TIA-EIA-IS-801

TIA/EIAINTERIM STANDARD

Position Determination ServiceStandard for Dual ModeSpread Spectrum Systems

TIA/EIA/IS-801

NOVEMBER 1999

TELECOMMUNICATIONS INDUSTRY ASSOCIATION

Representing the telecommunications industry inassociation with the Electronic Industries Alliance

TIA

/EIA

/IS-8

01

NOTICE

TIA/EIA Engineering Standards and Publications are designed to serve the public interest through eliminatingmisunderstandings between manufacturers and purchasers, facilitating interchangeability and improvement ofproducts, and assisting the purchaser in selecting and obtaining with minimum delay the proper product forhis particular need. Existence of such Standards and Publications shall not in any respect preclude anymember or nonmember of TIA/EIA from manufacturing or selling products not conforming to suchStandards and Publications, nor shall the existence of such Standards and Publications preclude theirvoluntary use by those other than TIA/EIA members, whether the standard is to be used either domesticallyor internationally.

Standards and Publications are adopted by TIA/EIA in accordance with the American National StandardsInstitute (ANSI) patent policy. By such action, TIA/EIA does not assume any liability to any patent owner,nor does it assume any obligation whatever to parties adopting the Standard or Publication.

TIA/EIA INTERIM STANDARDS

TIA/EIA Interim Standards contain information deemed to be of technical value to the industry, and arepublished at the request of the originating Committee without necessarily following the rigorous public reviewand resolution of comments which is a procedural part of the development of a TIA/EIA Standard.

TIA/EIA Interim Standards should be reviewed on an annual basis by the formulating Committee and adecision made on whether to proceed to develop a TIA/EIA Standard on this subject. TIA/EIA InterimStandards must be cancelled by the Committee and removed from the TIA/EIA Standards Catalog before theend of their third year of existence.

Publication of this TIA/EIA Interim Standard for trial use and comment has been approved by theTelecommunications Industry Association. Distribution of this TIA/EIA Interim Standard for comment shallnot continue beyond 36 months from the date of publication. It is expected that following this 36 monthperiod, this TIA/EIA Interim Standard, revised as necessary, will be submitted to the American NationalStandards Institute for approval as an American National Standard. Suggestions for revision should bedirected to: Standards & Technology Department, Telecommunications Industry Association, 2500 WilsonBoulevard, Arlington, VA 22201.

(From Project No. 4535, formulated under the cognizance of the TIA TR-45.5 Subcommittee on SpreadSpectrum Digital Technology.)

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2500 Wilson BoulevardArlington, VA 22201

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TIA/EIA/IS-801

i

CONTENTS�

1 GENERAL ......................................................................................................................... 1-1�

1.1 Terms ......................................................................................................................... 1-1�

2 MESSAGE TRANSPORT PROTOCOL ................................................................................ 2-1�

2.1 Analog Transport Protocol .......................................................................................... 2-1�

2.2 CDMA Transport Protocol........................................................................................... 2-1�

2.2.1 Session Tags ........................................................................................................ 2-1�

3 MOBILE STATION PROCEDURES .................................................................................... 3-1�

3.1 Analog Mobile Station Procedures .............................................................................. 3-1�

3.2 CDMA Mobile Station Procedures............................................................................... 3-1��

3.2.1 Position Determination Data Message Processing ................................................ 3-1��

3.2.1.1 Overview ........................................................................................................ 3-1��

3.2.1.2 Requirements................................................................................................. 3-2��

3.2.2 Point-to-point Procedures .................................................................................... 3-5��

3.2.2.1 Control Channel Procedure............................................................................ 3-5��

3.2.2.1.1 Mobile Position Message Termination ...................................................... 3-5��

3.2.2.1.1.1 Base Station Request Elements Received .......................................... 3-5��

3.2.2.1.1.2 Base Station Response Elements Received ........................................ 3-9��

3.2.2.1.2 Mobile Position Message Origination ....................................................... 3-9��

3.2.2.1.2.1 Position Determination Data Message Transmission Requirements .. 3-9��

3.2.2.1.2.2 Unsolicited Response Elements ....................................................... 3-10��

3.2.2.1.2.3 Request Elements............................................................................ 3-10��

3.2.2.2 Authentication Procedures........................................................................... 3-10��

3.2.2.3 Traffic Channel Procedure ........................................................................... 3-11��

3.2.2.3.1 Message Encryption............................................................................... 3-11��

3.2.2.3.2 Negotiation for the Position Determination Service Option .................... 3-11��

3.2.2.3.2.1 Procedures Using Service Negotiation.............................................. 3-11��

3.2.2.3.3 Mobile Position Message Termination .................................................... 3-13��

3.2.2.3.3.1 Base Station Request Elements Received ........................................ 3-13��

3.2.2.3.3.2 Base Station Response Elements Received ...................................... 3-17��

3.2.2.3.4 Traffic Channel Setup............................................................................ 3-17��

3.2.2.3.5 Mobile Position Message Origination in the Conversation Substate....... 3-18��

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ii

CONTENTS�

3.2.2.3.5.1 Position Determination Data Message Transmission Requirements 3-18�

3.2.2.3.5.2 Unsolicited Response Elements ....................................................... 3-18�

3.2.2.3.5.3 Request Elements............................................................................ 3-18�

3.2.3 Broadcast Procedures ........................................................................................ 3-18�

3.2.4 Reverse Link Message Format ............................................................................ 3-18�

3.2.4.1 Request Element Parameters Record ........................................................... 3-23�

3.2.4.2 Response Element Parameters Record......................................................... 3-27�

4 BASE STATION PROCEDURES ........................................................................................ 4-1�

4.1 Analog Base Station Procedures................................................................................. 4-1��

4.2 CDMA Base Station Procedures ................................................................................. 4-1��

4.2.1 Position Determination Data Message Processing ................................................ 4-1��

4.2.1.1 Overview ........................................................................................................ 4-1��

4.2.1.2 Requirements................................................................................................. 4-2��

4.2.2 Point-to-point Procedures .................................................................................... 4-4��

4.2.2.1 Control Channel Procedure............................................................................ 4-4��


4.2.2.1.1.1 Mobile Station Request Elements Received........................................ 4-4��

4.2.2.1.1.2 Mobile Station Response Elements Received ..................................... 4-7��

4.2.2.1.2 Mobile Position Message Termination ...................................................... 4-7��

4.2.2.1.2.1 Position Determination Data Message Transmission Requirements .. 4-7��

4.2.2.1.2.2 Unsolicited Response Elements ......................................................... 4-8��

4.2.2.1.2.3 Request Elements.............................................................................. 4-8��

4.2.2.2 Authentication Procedures............................................................................. 4-8��

4.2.2.3 Traffic Channel Procedure ............................................................................. 4-8��

4.2.2.3.1 Message Encryption................................................................................. 4-8��

4.2.2.3.2 Negotiation for the Position Determination Service Option ...................... 4-8��

4.2.2.3.2.1 Procedures Using Service Negotiation................................................ 4-9��


4.2.2.3.3.1 Mobile Station Request Elements Received...................................... 4-10��

4.2.2.3.3.2 Mobile Station Response Elements Received ................................... 4-12��

4.2.2.3.4 Traffic Channel Setup............................................................................ 4-12��

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iii

CONTENTS�

4.2.2.3.5 Mobile Station Message Termination in the Conversation Substate ...... 4-12�

4.2.2.3.5.1 Position Determination Data Message Transmission Requirements 4-12�

4.2.2.3.5.2 Unsolicited Response Elements ....................................................... 4-13�

4.2.2.3.5.3 Request Elements............................................................................ 4-13�

4.2.3 Broadcast Procedures ........................................................................................ 4-13�

4.2.4 Forward Link Message Format ........................................................................... 4-13�

4.2.4.1 Request Element Parameters Record ........................................................... 4-18�

4.2.4.2 Response Element Parameters Record......................................................... 4-22�

Annex A - TIMERS...............................................................................................................A-1��

Annex B – REQUEST/RESPONSE ELEMENT TYPES ..........................................................B-1��

Annex C – EXAMPLE POSITION DETERMINATION DATA MESSAGE..................................C-1��

TIA/EIA/IS-801

iv

TABLES

Table 3.2.1.2-1. Response Elements Sent in Response to Received Request Elements.....3-4�

Table 3.2.2.3.2.1-1. Valid Service Configuration Attributes for Service Option 35..........3-12�

Table 3.2.2.3.2.1-2. Valid Service Configuration Attributes for Service Option 36..........3-12�

Table 3.2.4-1. Reverse Link Messages ............................................................................3-19�

Table 3.2.4-2. Request Element Type .............................................................................3-22�

Table 3.2.4-3. Response Element Type ...........................................................................3-23�

Table 3.2.4.2-1. Reject Reason .......................................................................................3-28�

Table 3.2.4.2-2. Pilot Phase Capability ...........................................................................3-29�

Table 3.2.4.2-3. Mapping Table for GPS Acquisition Capability......................................3-29�

Table 3.2.4.2-4. Mapping Table for Position Calculation Capability ...............................3-30��

Table 3.2.4.2-5. Inverse of Weighting Factor Representation..........................................3-32��

Table 3.2.4.2-6. Time Reference Source .........................................................................3-34��

Table 3.2.4.2-7. Multipath Indicator...............................................................................3-36��

Table 3.2.4.2-8. Pseudorange RMS Error Representation...............................................3-36��

Table 3.2.4.2-9. RMS Error in Pilot Phase Measurement Representation .......................3-42��

Table 3.2.4.2-10. Position Uncertainty ...........................................................................3-46��

Table 4.2.1.2-1. Response Elements Sent in Response to Received Request Elements.....4-3��

Table 4.2.4-1. Forward Link Messages ...........................................................................4-14��

Table 4.2.4-2. Request Element Type .............................................................................4-17��

Table 4.2.4-3. Response Element Type ...........................................................................4-18��

Table 4.2.4.2-1. Reject Reason .......................................................................................4-23��

Table 4.2.4.2-2. Autonomous Location Determination Capability in the Base Station ...4-25��

Table 4.2.4.2-3. Reference PN.........................................................................................4-27��

Table 4.2.4.2-4. DOPPLER_WIN Parameter Format ........................................................4-28��

Table 4.2.4.2-5. Code Phase Search Window Parameter Format ....................................4-29��

Table 4.2.4.2-6. Position Uncertainty .............................................................................4-54��

Table A-1. Time Limits..................................................................................................... A-1��

Table B-1. MS Requests and BS Responses .................................................................... B-1��

Table B-2. MS Responses and BS Requests .................................................................... B-1��

Table C-1. Bit Field of the Position Determination Data Message.................................... C-1��

TIA/EIA/IS-801

v

FOREWORD�

(This foreword is not part of this standard)�

This Standard was prepared by Telecommunications Industry Association Subcommittee�

TR45.5, Spread Spectrum Digital Technology - Mobile and Personal Communications�

Standards.�

This standard is an adjunct standard to TIA/EIA-95-B, Mobile Station-Base Station�

Compatibility Standard for Dual-Mode Spread Spectrum Systems or TIA/EIA/IS-2000-5,�

Upper Layer (Layer 3) Signaling Standard for cdma2000 Spread Spectrum Systems. This�

standard defines a set of signaling messages between the mobile station and base station to�

provide a position determination service.��

This standard consists of the following sections:��

1. General. This section defines the terms and numeric indications used in this document.��

2. Message Transport Protocol. This section defines the transport protocol used between��

the mobile station and base station.��

3. Mobile Station Procedures. This section describes the procedures used by the mobile��

station to process messages received from the base station and to send messages to the��

base station. This section also specifies the message formats for messages sent from the��

mobile station to the base station.��

4. Base Station Procedures. This section describes the procedures used by the base��

station to process messages received from the mobile station and to send messages to the��

mobile station. This section also specifies the message formats for messages sent from the��

base station to the mobile station.��

Annex A. This section provides values from various timers used in the standard.��

Annex B. This section provides the summary tables of the request/response element��

types.��

Annex C. This section provides an example of the Position Determination Data Message.��

TIA/EIA/IS-801

vi

NOTES�

1. For purposes of this standard, “shall” and “shall not” identify requirements to be�

followed strictly to conform to the standard, and from which no deviation is�

permitted. “Should” and “should not” indicate that one of several possibilities is�

recommended as particularly suitable, without mentioning or excluding others; that�

a certain course of action is preferred, but not necessarily required; or (in negative�

form) that a certain possibility or course of action is discouraged, but not�

prohibited. “May” and “may not” indicate a course of action permissible within the�

limits of this standard. “Can” and “cannot” are used for statements of possibility�

and capability, whether material, physical or causal.��

2. The terms “location” and “position” are used interchangeably throughout this��

document. In this respect the definition of the term differs from the historic use of��

location in wireless systems to identify the mobile’s current serving system.��

3. Those wishing to deploy systems in the United States should also take notice of the��

requirement to be compliant with Federal Communications Commission (FCC)��

Rulings on 911 Emergency Services.��

4. “Base station” refers to the functions performed on the land side, which are typically��

distributed among a Base Station Transceiver (BTS), a Base Station Controller��

(BSC), a Mobile Switching Center (MSC), Mobile Positioning Center (MPC), Position��

Determination Entity (PDE) and any Inter-Working Function (IWF) required for��

network connection. These elements are grouped together, because there is no need��

to distinguish them in an air interface standard. See TSB-100 Wireless Reference��

Model and Enhanced Wireless 9-1-1 Phase 2 (to be released, currently PN-3890).��

5. Footnotes appear at various points in this specification to elaborate and to further��

clarify items discussed in the body of the specification.��

6. Unless indicated otherwise, this document presents numbers in decimal form.��

Binary numbers are distinguished in the text by the use of single quotation marks.��

7. The following operators define mathematical operations:��

× indicates multiplication.��

x indicates the largest integer less than or equal to x: 1.1 = 1, 1.0 = 1.��

x indicates the smallest integer greater or equal to x: 1.1 = 2, 2.0 = 2.��

|x| indicates the absolute value of x: |-17|=17, |17|=17.��

⊕ indicates exclusive OR (modulo-2 addition).��

min (x, y) indicates the minimum of x and y.��

max (x, y) indicates the maximum of x and y.��

x mod y indicates the remainder after dividing x by y: x mod y = x - (y × x/y).��

8. References in this document are to TIA/EIA-95-B. This standard is equally��

applicable to TIA/EIA/IS-2000. Except where explicit references are made to��

TIA/EIA/IS-2000, the reference to TIA/EIA-95-B can be converted directly to��

TIA/EIA/IS-2000 usage.��

TIA/EIA/IS-801

vii

9. Wherever this document refers to CDMA System time in frames, it is taken to mean�

an integer value t such that: t = s/0.02, where s represents System Time in�

seconds.�

TIA/EIA/IS-801

viii

REFERENCES�

The following standards contain provisions which, through reference in this text, constitute�

provisions of this standard. At the time of publication, the editions indicated were valid.�

All standards are subject to revision, and parties to agreements based on this standard are�

encouraged to investigate the possibility of applying the most recent editions of the�

standards indicated below. ANSI and TIA maintain registers of currently valid national�

standards published by them.�

�

1. TIA/EIA-95-B, Mobile Station-Base Station Compatibility Standard for Dual-Mode�

Spread Spectrum Systems, March 1999.��

2. TIA/EIA/TSB58-B, Administration of Parameter Value Assignments for TIA/EIA��

Spread Spectrum Standards, August 1999.��

3. ICD-GPS-200C, Navstar GPS Space Segment / Navigation User Interfaces, September��

1997.��

4. DMA TR 8350.2, Defense Mapping Agency Publication, September 30, 1987.��

5. Enhanced Wireless 9-1-1 Phase 2. TR45.2 AHES. To be released. (Currently��

PN-3890).��

6. Beyond Enhanced Wireless 9-1-1 Phase 2. TR45.2 AHES. To be released.��

(Currently PN-4288).��

7. Geo-Location Support on the Analog Air Interface. TR45.1.1.1. To be released.��

(Currently PN-4662).��

8. TSB-100, Wireless Network Reference Model, July 1998.��

9. TIA/EIA/IS-2000-1, Introduction to cdma2000 Standards for Spread Spectrum��

System, July 1999.��

10. TIA/EIA/IS-2000-2, Medium Access Control (MAC) Standards for cdma2000 Spread��

Spectrum Systems, July 1999.��

11. TIA/EIA/IS-2000-3, Signaling Link Access Control (LAC) Standard for cdma2000��

Spread Spectrum Systems, July 1999.��

12. TIA/EIA/IS-2000-4, Upper Layer (Layer 3) Signaling Standard for cdma2000 Spread��


13. TIA/EIA/IS-2000-5, Upper Layer (Layer 3) Signaling Standard for cdma2000 Spread��


14. TIA/EIA/IS-2000-6, Analog Signaling Standard for cdma2000 Spread Spectrum��

Systems, July 1999.��

TIA/EIA/IS-801

1-1

1 GENERAL�

1.1 Terms�

2D Fix. A two-dimensional (latitude and longitude) position determination process.�

3D Fix. A three-dimensional (latitude, longitude and height) position determination�

process.�

Advanced Forward Link Trilateration (AFLT). A geolocation technique that utilizes the�

mobile station’s measured time of arrival of radio signals from the base stations (and,�

possibly, other terrestrial measurements).�

AFLT. See Advanced Forward Link Trilateration.�

Almanac. See GPS Almanac.��

Alpha. See Alpha, Beta Parameters.��

Alpha, Beta Parameters. Ionospheric parameters which allow the “L1 only” user to utilize��

the ionospheric mode for computation of ionospheric delay are contained in page 18 of��

subframe 4 of GPS navigation data.��

Angle of Axis for Position Uncertainty. Position uncertainty is represented as a 1-σ (one��

standard deviation) ellipse. This angle is the angle of one of the ellipse’s axes with respect��

to True North.��

Assistance Data. The assistance data provided by the base station to the mobile station��

for various purposes (e.g., acquisition, location calculation or sensitivity improvement).��

Authentication. A procedure used by a base station to validate a mobile station’s identity.��

Autonomous Mobile Station. A mobile station that is capable of detecting a navigation��

signal without any help from the base station. The mobile station may be capable of��

autonomously calculating its own position.��

Autonomous Base Station. A base station capable of determining the location of the��

mobile station without requiring any cooperation from the mobile station.��

Azimuth. An angle that specifies a direction in the horizontal plane, expressed in degrees��

measured clockwise from True North.��

Base Station. The base station includes the transceiver equipment, Mobile Switching��

Center (MSC), Mobile Positioning Center (MPC), Position Determination Entity (PDE) and��

any Inter-Working Function (IWF) required for network connection.��

Base Station Almanac. The location and reference time correction for a collection of base��

stations in the immediate neighborhood of the mobile station (the size of the immediate��

neighborhood is a service provider option).��

Beta. See Alpha, Beta Parameters.��

C/A Code. Coarse/Acquisition code used for spectral spreading of the GPS signal.��

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1-2

C/A Code Chip. The interval defined by the chipping (spreading) rate of the GPS C/A code.�

Stated as a time interval, one chip equals approximately 977.5 ns; as a distance it is�

approximately 293.0 m.�

C/N0. The ratio of carrier signal power (C) to the power spectral density of background�

noise (N0).�

CDMA System Time. All base station digital transmissions are referenced to a common�

CDMA system-wide time scale that uses the Global Positioning System (GPS) time scale,�

which is traceable to and synchronous with Universal Coordinated Time (UTC). GPS and�

UTC differ by an integer number of seconds, specifically the number of leap second�

corrections added to UTC since January 6, 1980. The start of CDMA System Time is��

January 6, 1980 00:00:00 UTC, which coincides with the start of GPS time. (See��

TIA/EIA/95-B Section 1.2).��

Clock Bias. The difference between the GPS System Time and the local time in the mobile��

station.��

Clock Drift. The rate of change of the clock bias.��

Code Phase. At a given time, the code phase is the fraction of the code period that has��

elapsed since the latest code boundary.��

Code Phase Search Window. The expected range of possible code phase values.��

DGPS. Differential GPS.��

Doppler nth Order. The nth order moment specifying a satellite’s observed Doppler.��

Doppler Search Window. The expected range of possible Doppler values.��

ECEF. “Earth-Centered-Earth-Fixed”. A frame of reference for specifying positions that is��

centered in the center of the Earth and rotates with it.��

Elevation Angle. The angle between a (GPS) satellite and the horizon, expressed in��

degrees.��

Ephemeris. The ephemeris data embedded in the GPS signal. The precise (high accuracy)��

orbital parameters of one GPS satellite, as transmitted by that satellite in GPS subframes 1,��

2, and 3. The ephemeris also includes satellite clock correction.��

Extended Base Station Almanac. The location and reference time correction for a��

collection of base stations in the extended neighborhood of the mobile station (the size of��

the extended neighborhood is a service provider option).��

Fix. The process of performing position computation.��

Frame. See GPS Navigation Message Frame.��

Geolocation. The process of determining a geographic location.��

GPS. Global Positioning System.��

GPS Almanac. The almanac data embedded in the GPS signal. The almanac data are a��

reduced-precision subset of the clock and ephemeris parameters for all satellites, as��

transmitted by every satellite in GPS subframes 4 and 5.��

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1-3

GPS Navigation Message Frame. A GPS navigation message frame contains five�

subframes. Subframes 1 through 3 contain ephemeris information, subframes 4 and 5�

contain message and almanac information.�

GPS Navigation Message Subframe. One of the five GPS subframes of the GPS navigation�

message. Subframe is 300-bits long.�

GPS Navigation Message Superframe. A GPS navigation message superframe consists of�

25 frames and has a duration of 12.5 minutes.�

ICD. Interface Control Document.�

IWF. InterWorking Function. A network entity enabling interactions between network�

elements, such as interactions between an MSC and a landline function. The IWF usually��

performs protocol conversions as its primary function.��

Legacy Terminal. A mobile station that is not compliant with the messages defined in��

this document.��

Location. The terms “location” and “position” are used interchangeably throughout this��

document. In this respect, the definition of the term differs from the historic use of location��

in wireless systems to identify the mobile’s current serving system. See Position.��

LSB. Least Significant Bit.��

MPC. Mobile Positioning Center: The network entity that serves as the point of interface of��

the wireless network for the exchange of geographic position information.��

Mobile Station (MS). A station that communicates with the base station.��

Mobile Station Originated Message. A message originating from a mobile station.��

Mobile Station Terminated Message. A message received by a mobile station.��

Mobile Switching Center (MSC). A configuration of equipment that provides cellular��

radio-telephone service. Also called the Mobile Telephone Switching Office (MTSO).��

ms. Millisecond (10-3 second).��

MS. See Mobile Station.��

MSB. Most Significant Bit.��

MSC. See Mobile Switching Center.��

Navigation Message Bits. The message bits (50 bits per second) transmitted by GPS��

satellites, containing the satellite clock, ephemeris, almanac and other parameters.��

ns. Nanosecond (10-9 second).��

PDE. See Position Determination Entity.��

PN Offset. The PN offset measured in units of 64 PN chips of a pilot, relative to the zero-��

offset pilot PN sequence.��

Position. The geographic position of the mobile station expressed in latitude and��

longitude.��

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1-4

Position Determination Entity (PDE). A network entity which manages the position or�

geographic location determination of the mobile station.�

ppb. Parts per billion.�

Pseudodoppler. The measured Doppler frequency shift in the signal received from the GPS�

satellite. Since the satellite and receiver clock drifts are included, it is referred to as�

pseudodoppler.�

Pseudorange. The measured range (in GPS chip) from the observed satellite to the GPS�

receiver antenna. Since the satellite and receiver clock biases are included, it is referred to�

as pseudorange.�

Push. An unsolicited response.��

Reference Bit Boundary. A boundary between two 20-ms GPS bit intervals chosen as the��

reference point for code phases.��

Sensitivity. The minimum level (dBm) of received GPS signal at mobile station that allows��

the determination of the geolocation of the mobile station.��

Subframe. See GPS Navigation Message Subframe.��

Superframe. See GPS Navigation Message Superframe.��

SV. Space Vehicle; a way of referring to one of the GPS satellites; note SV will often be��

used in this context as part of a message name, so the message is associated with a��

satellite.��

PRN Number. The GPS PRN signal number as defined in ICD-GPS-200C, table 3-I.��

Time of Arrival. The time occurrence, as measured at the mobile station antenna��

connector, of the earliest arriving usable multipath component of the signal.��

Unsolicited Response. A response element that is issued in the absence of the��

corresponding request element.��

Weighting Factor. Weighting factor is a weight applied to the GPS measurement as part of��

a Weighted Least Squares Filter (WLSF) implementation of the navigation algorithm used by��

the Mobile Station to compute its position.��

WGS-84. World Geodetic System - 1984.��

WGS-84 reference ellipsoid. Worldwide datum reference system defining the surface of��

the Earth (note: Supersedes WGS-72), i.e., the standard physical model of the Earth used��

for GPS applications. Ellipsoid reference models are location specific and may be obtained��

from Defense Mapping Agency publication DMA TR 8350.2 (September 30, 1987).��

WLSF. Weighted Least Squares Filter navigation algorithm.��

TIA/EIA/IS-801

2-1

2 MESSAGE TRANSPORT PROTOCOL�

Position Determination Data Messages (see 3 and 4) can be sent over the CDMA Traffic�

Channel or the CDMA Control Channel. Position Determination Data Messages are sent�

using a Layer-2 protocol that provides reliable delivery and duplicate detection.�

2.1 Analog Transport Protocol�

The analog transport protocol is defined in [7].�

2.2 CDMA Transport Protocol�

The message defined in 3.2.4 and 4.2.4 shall be sent in the CHARi fields of Data Burst�

Messages (see 6.7.1.3.2.3, 6.7.2.3.2.4, 7.7.2.3.2.9 and 7.7.3.3.2.4 of TIA/EIA-95-B). The�

BURST_TYPE field of Data Burst Messages carrying Position Determination Data Messages��

shall be set to ‘000101’ (as assigned in TSB58-B). The MSG_NUMBER and NUM_MSGS��

fields shall be set to 1 and the NUM_FIELDS fields shall be set to the number of octets in��

the Position Determination Data Message. Data Burst Messages carrying Position��

Determination Data Message shall be sent as messages requiring Layer-2 acknowledgement��

(see 6.6.4.1.3.1 and 7.6.4.1.3.1 of TIA/EIA-95-B).��

2.2.1 Session Tags��

The first CHARi field of each Data Burst Message of BURST_TYPE ‘000101’ is intended to��

identify groups of Position Determination Data Messages that are related to one another.��

The purpose is to assist the network in routing the data to the proper destination.��

Two Position Determination Data Messages are defined to be related, and the elements or��

parts of elements they contain are defined to be related if any of the following is true.��

• One Position Determination Data Message contains a request element and the other��

Position Determination Data Message contains the associated response element or��

part of the associated response element.��

• One Position Determination Data Message contains part of a response element and��

the other Position Determination Data Message contains another part of the same��

response element.1��

• The sending entity (mobile station or base station) of a Position Determination Data��

Message had previously received or previously sent another Position Determination��

Data Message, and the two Position Determination Data Messages contain elements��

that are related. The criteria for determining if a relation exists are defined by the��

sending entity in an implementation-dependent fashion.��

The structure of the first CHARi field is detailed in 3.2.4 and 4.2.4. It includes a session��

tag (SESS_TAG) and three flags. Procedures for assigning a value to SESS_TAG are also��

detailed in 3.2.4 and 4.2.4.��

1 This definition covers unsolicited responses that are divided into several parts in differentmessages.

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All request elements, response elements, and parts of response elements that are related�

should, if possible, be included in the same Position Determination Data Message. A�

Position Determination Data Message shall only include request elements, response�

elements, or parts of response elements that are mutually related.�

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3 MOBILE STATION PROCEDURES�

3.1 Analog Mobile Station Procedures�

The analog mobile station procedures are defined in [7].�

3.2 CDMA Mobile Station Procedures�

3.2.1 Position Determination Data Message Processing�

3.2.1.1 Overview�

The Position Determination Data Message sent by the mobile station is comprised of request�

elements and response elements, as specified below.�

Request elements sent by mobile station:�

• Request BS Capabilities��

• Request GPS Acquisition Assistance��

• Request GPS Location Assistance��

• Request GPS Sensitivity Assistance��

• Request Base Station Almanac��

• Request GPS Almanac��

• Request GPS Ephemeris��

• Request GPS Navigation Message Bits��

• Request Location Response��

• Request GPS Almanac Correction��

Response elements sent by mobile station:��

• Reject��

• Provide MS Information��

• Provide Autonomous Measurement Weighting Factors��

• Provide Pseudorange Measurement��

• Provide Pilot Phase Measurement��

• Provide Location Response��

• Provide Time Offset Measurement��

• Provide Cancellation Acknowledgement��

The Position Determination Data Message received by the mobile station is also comprised of��

request elements and response elements, as specified below.��

Request elements received by mobile station:��

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• Request MS Information�

• Request Autonomous Measurement Weighting Factors�

• Request Pseudorange Measurement�

• Request Pilot Phase Measurement�

• Request Location Response�

• Request Time Offset Measurement�

• Request Cancellation�

Response elements received by mobile station:�

• Reject�

• Provide BS Capabilities��

• Provide GPS Acquisition Assistance��

• Provide GPS Location Assistance – Spherical Coordinates��

• Provide GPS Location Assistance – Cartesian Coordinates��

• Provide GPS Sensitivity Assistance��

• Provide Base Station Almanac��

• Provide GPS Almanac��

• Provide GPS Ephemeris��

• Provide GPS Navigation Message Bits��


• Provide GPS Almanac Correction��

Response elements sent by the mobile station may be generated in response to request��

elements received by the mobile station or they may be generated as unsolicited response��

elements. Every request element includes a REQ_TYPE (request element type) field that��

uniquely identifies the request element (See Table 3.2.4-2). Every response element��

includes a RESP_TYPE (response element type) field that uniquely identifies the response��

element (See Table 3.2.4-3). Multiple response elements may be associated with a single��

request element. Unsolicited response elements are sent with the UNSOL_RESP flag set to��

‘1’ (see 3.2.4).��

3.2.1.2 Requirements��

Each Position Determination Data Message shall contain at least one request element, or at��

least one part of a response element, or both. No more than one request element of a��

specific REQ_TYPE shall be included in a Position Determination Data Message. Each��

request element shall be fully contained in a Position Determination Data Message. Some��

response elements may be divided into parts (see 3.2.4.2). Each response element part��

shall be fully contained in a Position Determination Data Message. All Position��

Determination Data Messages shall be no larger than 200 bytes.��

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If the mobile station sends a response element in response to a received request element, it�

shall comply with Table 3.2.1.2-1. A “Reject” shall not be sent as a response element to a�

“Request MS Information” request element. A “Reject” shall not be sent as a response�

element to a “Request Cancellation” request element.�

If one or more response elements from the mobile station can be useful to the base station�

in responding to a request from the mobile station, the mobile station should include all or�

part of each response element and the request element in the same Position Determination�

Data Message.�

Upon receiving a Position Determination Data Message, the mobile station should examine�

the received response elements prior to processing the request elements.2��

2 Consider, for example, the case in which a base station asks a mobile station for alocation fix while, at the same time, providing acquisition assistance that is needed toachieve the fix. In that case, the base station would issue a Position Determination DataMessage containing both the request for a location fix (Request Location Responsemessage) and an unsolicited response with the acquisition assistance (Provide GPSAcquisition Assistance message). Sending a message with both the request and responseavoids the additional exchange of messages that would otherwise occur if the mobile stationhad to issue a request for acquisition assistance and wait for the response. However, forthis example to work correctly, the mobile station must be aware that the acquisitionassistance is available when it processes the request for a fix; hence, the recommendationthat response elements should be “examined” prior to processing the request elements.

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Table 3.2.1.2-1. Response Elements Sent in Response to Received Request Elements�

Request element received Possible response elements

Request MS Information Provide MS Information

RejectRequest Autonomous MeasurementWeighting Factors Provide Autonomous Measurement

Weighting Factors

RejectRequest Pseudorange Measurement

Provide Pseudorange Measurement

RejectRequest Pilot Phase Measurement

Provide Pilot Phase Measurement

RejectRequest Location Response

Provide Location Response

RejectRequest Time Offset Measurement

Provide Time Offset Measurement

Request Cancellation Provide CancellationAcknowledgement

�

No more than one request element shall be outstanding at any given time for each�

REQ_TYPE. If an additional request element is received while there is an outstanding�

request element of the same type, the additional request element shall be discarded. A�

received request element is considered outstanding until all of the corresponding response�

elements or a “Reject” have been sent or until a “Request Cancellation” for the request�

element has been received. The mobile station should wait T9 (see ANNEX A) seconds for a�

response or a “Reject” to a sent request element; after T9 seconds the request element�

should no longer be considered outstanding. Unsolicited response elements shall have the��

UNSOL_RESP flag set to ‘1’. If the mobile station while in the Mobile Station Idle State��

performs an idle handoff (see section 6.6.2.1.4 of TIA/EIA-95B) to a base station with��

different SID/NID, it shall discard all of the outstanding request elements. If the mobile��

station switches from an analog system to a CDMA system or switches from a CDMA��

system to an analog system, the mobile station shall discard all of the outstanding request��

elements. If the mobile station, while in the Mobile Station Conversation Substate of Mobile��

Station Control on the Traffic Channel State, performs a handoff (see section 6.6.6.2.9 of��

TIA/EIA-95B) to an analog system, the mobile station shall discard all of the outstanding��

request elements.��

If a “Reject” constitutes the response element, its REJ_REQ_TYPE shall be set to the��

REQ_TYPE of the corresponding request element.��

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3.2.2 Point-to-point Procedures�

This section defines the procedures for the processing of mobile-terminated Position�

Determination Data Messages that are addressed to individual mobile stations and for the�

processing of all mobile-originated Position Determination Data Messages.�

3.2.2.1 Control Channel Procedure�

3.2.2.1.1 Mobile Position Message Termination�

A mobile station supporting Position Determination shall accept and shall process Data�

Burst Messages received while the mobile station is monitoring the CDMA Paging Channel�

(see 7.7.2.3.2.9 of TIA/EIA-95-B) that are addressed to the mobile station. Processing of�

TIA/EIA-95-B Layer-2 fields shall be in accordance with TIA/EIA-95-B. Data Burst��

Messages used to transport Position Determination request and response elements shall��

always be acknowledged (Layer 2) and the in-order delivery over the air interface shall be��

guaranteed by the transmitting entities: Mobile station and base station.��

The mobile station shall process all Data Burst Messages addressed to the mobile station��

on the Paging Channel and having the BURST_TYPE field set to ‘000101’ (as assigned in��

TSB58-B). The mobile station shall discard the message without further processing if one��

or more of the following is true:��

• MSG_NUMBER field is set to a value other than 1.��

• NUM_MSGS field is set to a value other than 1.��

• NUM_FIELDS field is set to zero.��

Otherwise, the mobile station shall process the Position Determination Data contained in��

the CHARi fields of the received Data Burst Message (see 7.7.2.3.2.9 of TIA/EIA-95-B), as��

described below.��

3.2.2.1.1.1 Base Station Request Elements Received��

If the mobile station does not support the requested capability, the mobile station shall��

respond with a “Reject” response element with the appropriate reject reason (see Table��

3.2.4.2-1), unless the base station request element is “Request MS Information” or “Request��

Cancellation” (these request elements cannot be rejected); otherwise, the mobile station��

shall include the appropriate response elements in the response Position Determination��

Data (see 3.2.4) as described below. The response Position Determination Data shall reside��

in the CHARi field of the response Data Burst Message (see 6.7.1.3.2.3 of TIA/EIA-95-B).3��

• Request MS Information: The mobile station shall include the “Provide MS��

Information” response element in the response Position Determination Data. The��

response Position Determination Data Message shall be sent within 750 ms of the��

reception of the “Request MS Information”.��

3 The parameters discussed in this subsection are defined in 4.2.4.1.

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• Request Autonomous Measurement Weighting Factors: The mobile station shall�

include the “Provide Autonomous Measurement Weighting Factors” response�

element in the response Position Determination Data. The PREF_RESP_QUAL�

indicator provided in the “Request Location Response” shall also apply to the�

“Request Autonomous Measurement Weighting Factors” request element.�

• Request Pseudorange Measurement: The mobile station shall send one or more�

“Provide Pseudorange Measurement” response elements, according to that which is�

specified by NUM_FIXES (Number of Fixes) and T_BETW_FIXES (Time between�

Fixes) included in the “Request Pseudorange Measurement”. The mobile station�

shall include the “Provide Pseudorange Measurement” response element in one or��

more response Position Determination Data Messages, according to the number of��

parts into which the response element is divided. The mobile station should use the��

mobile station time reference as defined in TIA/EIA-95 as the time reference used to��

perform the pseudorange measurements.4 If the mobile station is unable to use the��

mobile station time reference, as defined in TIA/EIA-95, to measure the��

pseudoranges, then the mobile station shall use an alternate time reference to��

perform the pseudorange measurements. The mobile station shall set the��

TIME_REF_SRC field in the “Provide Pseudorange Measurement” response element��

to the appropriate value to indicate the source of the time reference used to perform��

the pseudorange measurements. The mobile station shall set the periodic rate of��

measurement collection equal to the value of T_BETW_FIXES.��

² If PREF_RESP_QUAL is set to ‘000’, the “Provide Pseudorange Measurement”��

response element shall be sent within T1 seconds of the time corresponding��

to the beginning of the measurement collection period; if PREF_RESP_QUAL��

is set to ‘001’, the “Provide Pseudorange Measurement” response element��

shall be sent within T2 seconds of the time corresponding to the beginning of��

the measurement collection period; if PREF_RESP_QUAL is set to ‘010’, the��

“Provide Pseudorange Measurement” response element shall be sent within��

T3 seconds of the time corresponding to the beginning of the measurement��

collection period; if PREF_RESP_QUAL is set to ‘011’, the “Provide��

Pseudorange Measurement” response element shall be sent within T4��

seconds of the time corresponding to the beginning of the measurement��










4 The time reference used to perform the pseudorange measurements should be initializedfrom the mobile station time reference as defined in TIA/EIA-95.

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collection period; if PREF_RESP_QUAL is set to ‘111’, the “Provide�

Pseudorange Measurement” response element shall be sent within T8�

seconds of the time corresponding to the beginning of the measurement�

collection period.�

² If OFFSET_REQ is set to ‘1’, the “Provide Pseudorange Measurement”�

response element shall include REF_PN and MOB_SYS_T_OFFSET;�

otherwise the “Provide Pseudorange Measurement” response element should�

not include REF_PN and MOB_SYS_T_OFFSET.�

• Request Pilot Phase Measurement: The mobile station shall send one or more�

“Provide Pilot Phase Measurement” response elements, according to that which is��

specified by NUM_FIXES (Number of Fixes) and T_BETW_FIXES (Time between��

Fixes) included in the “Request Pilot Phase Measurement”. The mobile station shall��

include the “Provide Pilot Phase Measurement” response element in one or more��

response Position Determination Data Messages according to the number of parts��

into which the response element is divided. The mobile station shall set the periodic��

rate of measurement collection equal to the value of T_BETW_FIXES.��

² If PREF_RESP_QUAL is set to ‘000’, the “Provide Pilot Phase Measurement”��



is set to ‘001’, the “Provide Pilot Phase Measurement” response element shall��

be sent within T2 seconds of the time corresponding to the beginning of the��

measurement collection period; if PREF_RESP_QUAL is set to ‘010’, the��

“Provide Pilot Phase Measurement” response element shall be sent within T3��


collection period; if PREF_RESP_QUAL is set to ‘011’, the “Provide Pilot��

Phase Measurement” response element shall be sent within T4 seconds of the��

time corresponding to the beginning of the measurement collection period; if��

PREF_RESP_QUAL is set to ‘100’, the “Provide Pilot Phase Measurement”��










time corresponding to the beginning of the measurement collection period.��

² If DESI_PIL_PH_RES is set to ‘1’, the "Provide Pilot Phase Measurement”��

response element shall5 be of at least 1/8 of TIA/EIA-95 PN chip resolution;��

5 If the mobile station rejects the request with 1/8 chip resolution, it may send anunsolicited response (see 3.2.1.1) with 1 chip resolution.

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otherwise, the “Provide Pilot Phase Measurement” response element shall be�

of at least 1 TIA/EIA-95 PN chip resolution.�

² If OFFSET_REQ is set to ‘1’, the “Provide Pilot Phase Measurement” response�

element shall include MOB_SYS_T_OFFSET; otherwise the “Provide Pilot�

Phase Measurement” response element should not include�

MOB_SYS_T_OFFSET.�

• Request Location Response: The mobile station shall send one or more “Provide�

Location Response” response elements, according to that which is specified by�

NUM_FIXES (Number of Fixes) and T_BETW_FIXES (Time between Fixes) included�

in the “Request Location Response”. The mobile station shall include the “Provide��

Location Response” response element in one or more response Position��

Determination Data Messages according to the number of parts into which the��

response element is divided. The mobile station shall set the periodic rate of��


² If PREF_RESP_QUAL is set to ‘000’, the “Provide Location Response”��



is set to ‘001’, the “Provide Location Response” response element shall be��

sent within T2 seconds of the time corresponding to the beginning of the��


“Provide Location Response” response element shall be sent within T3��


collection period; if PREF_RESP_QUAL is set to ‘011’, the “Provide Location��

Response” response element shall be sent within T4 seconds of the time��

corresponding to the beginning of the measurement collection period; if��

PREF_RESP_QUAL is set to ‘100’, the “Provide Location Response” response��

element shall be sent within T5 seconds of the time corresponding to the��

beginning of the measurement collection period; if PREF_RESP_QUAL is set��

to ‘101’, the “Provide Location Response” response element shall be sent��

within T6 seconds of the time corresponding to the beginning of the��






corresponding to the beginning of the measurement collection period.��

² If HEIGHT_REQ is set to ‘1’, the “Provide Location Response” response��

element should include height information; otherwise, the “Provide Location��

Response” response element should not include height information.��

² If CLK_COR_GPS_REQ is set to ‘1’, the “Provide Location Response” response��

element should include clock correction for GPS time; otherwise, the “Provide��

Location Response” response element should not include clock correction for��

GPS time.��

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² If VELOCITY_REQ is set to ‘1’, the “Provide Location Response” response�

element should include velocity information; otherwise, the “Provide Location�

Response” response element should not include velocity information.�

• Request Time Offset Measurement: The mobile station shall include a “Provide Time�

Offset Measurement” response element in the response Position Determination�

Data. If USE_TIME is set to ‘1’, the “Provide Time Offset Measurement” response�

element shall include the offset information determined to be valid at the�

ACTION_TIME. If USE_TIME is set to ‘0’, the “Provide Time Offset Measurement”�

response element shall include the offset information determined to be valid at the�

time the “Request Time Offset Measurement” is received by the mobile station. If��

USE_TIME is set to ‘1’, the “Provide Time Offset Measurement” response element��

shall be sent within 750 ms of ACTION_TIME. If USE_TIME is set to ‘0’, the “Provide��

Time Offset Measurement” response element shall be sent within 750 ms of the��

reception of the “Request Time Offset Measurement” request element.��

• Request Cancellation: The mobile station shall cancel the outstanding request��

element indicated by CANCEL_TYPE. The mobile station shall include a “Provide��

Cancellation Acknowledgement” response element in the Position Determination Data��

Message to indicate the successful cancellation of the outstanding request element.��

If the mobile station has no outstanding request element of the type indicated by��

CANCEL_TYPE, it shall set the NO_OUT_REQ flag in the “Provide Cancellation��

Acknowledgment” response element. The “Provide Cancellation Acknowledgement”��

response element shall be sent within 750 ms of the reception of the “Request��

Cancellation” request element.��

3.2.2.1.1.2 Base Station Response Elements Received��

The mobile station should process and should make use of base station response elements.��

Upon receiving a Position Determination Data Message, the mobile station should examine��

the received response elements prior to processing the request elements.��

If the mobile station receives “Provide GPS Almanac Correction” response element, the��

mobile station shall process the response element as follows.��

• If DELTA_XYZ_INCL is ‘0’, the mobile station shall set the values of DELTA_X,��

DELTA_Y, DELTA_Z, DELTA_X_1ST, DELTA_Y_1ST and DELTA_Z_1ST to 0.��

• If DELTA_CLOCK_INCL is ‘0’, the mobile station shall set the values of��

DELTA_CLOCK and DELTA_CLOCK_1ST to 0.��

3.2.2.1.2 Mobile Position Message Origination��

3.2.2.1.2.1 Position Determination Data Message Transmission Requirements��

Mobile stations supporting Position Determination shall support the Mobile Station Message��

Transmission Operation, as defined in 6.6.2.6 of TIA/EIA-95-B.��

When the mobile station is in the TIA/EIA-95-B Mobile Station Idle State and needs to send��

one (or more) Position Determination Data Message(s), the mobile station shall determine��

whether the Position Determination Data Message(s) is (are) suitable for transmission on the��

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Access Channel6. As part of this determination, the mobile station shall determine whether�

the length of the Position Determination Data Message(s) is such that the message(s) can be�

sent on the Access Channel. If the Position Determination Data Message(s) is (are) not�

suitable for the Access Channel, the mobile station shall send the Position Determination�

Data Message(s) on the CDMA Traffic Channel, following the procedures defined in 3.2.2.3.�

If the Position Determination Data Message(s) is (are) suitable to be sent on the Access�

Channel, the mobile station may form one (or more) Data Burst Message(s) (see 6.7.1.3.2.3�

of TIA/EIA-95-B), setting BURST_TYPE to ‘000101’, and send it (them) on the Access�

Channel, following the procedure specified in 6.6.2.6 and 6.6.3 of TIA/EIA-95-B. The�

mobile station shall set NUM_FIELDS field to the number of octets in the Position��

Determination Data Message (see 3.2.4). The mobile station address fields shall be set��

using the address parameter stored in the mobile station. The authentication fields shall��

be set, as described in 3.2.2.2, using the authentication parameter stored in the mobile��

station. The Data Burst Message contains the Position Determination Data in the CHARi��

fields (see 6.7.1.3.2.3 of TIA/EIA-95-B). The mobile station shall wait for an appropriate��

response from the base station in accordance with the mobile station request elements.��

When the mobile station is in the TIA/EIA-95-B System Access State, the mobile station��

shall wait until it exits the System Access State. If the mobile station enters the Mobile��

Station Idle State, the mobile station shall follow the procedures specified in the above��

paragraph. If the mobile station enters the Mobile Station Control on Traffic Channel State,��

the mobile station shall follow the procedures defined in 3.2.2.3. If the mobile station��

enters an analog mode task, the mobile station shall follow the procedures for a mobile��

station in analog mode (see 3.1).��

Position Determination Data Messages sent on the Access Channel always require a��

TIA/EIA-95-B Layer-2 acknowledgement and the in-order delivery over the air interface��

shall be guaranteed by the mobile station.��

3.2.2.1.2.2 Unsolicited Response Elements��

Reserved��

3.2.2.1.2.3 Request Elements��

Reserved��

3.2.2.2 Authentication Procedures��

When sending a Data Burst Message on the Access Channel, the mobile station shall use��

the authentication procedures defined in 6.3.12 of TIA/EIA-95-B. The authentication��

parameter shall consist of six 4-bit digits, encoded according to TIA/EIA-95-B Table��

6.7.1.3.2.4-4. The digits shall be generated from the first three CHARi fields of the Data��

Burst Message.��

6 The criteria for suitability are implementation dependent.

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The sequence of digits in the authentication parameter shall be used to compute the�

authentication fields of the Data Burst Message in accordance with 6.3.12.1.8 of TIA/EIA-�

95-B.�

3.2.2.3 Traffic Channel Procedure�

3.2.2.3.1 Message Encryption�

To enhance the security of the position determination session and to protect sensitive�

subscriber location information, Position Determination Data Messages on the Traffic�

Channel should be encrypted as deemed appropriate. Encryption of the Forward and�

Reverse CDMA Traffic Channel messages is defined in 6.3.12.2 of TIA/EIA-95-B and Annex�

A of TIA/EIA-95-B.��

3.2.2.3.2 Negotiation for the Position Determination Service Option��

Negotiation for the Position Determination Service Option is only required when no other��

service option is connected.��

The Position Determination Service Option described by this standard shall use service��

option number 35 and is called Service Option 35 when using Multiplex Option 1. The��

Position Determination Service Option shall use service option number 36 and is called��

Service Option 36 when using Multiplex Option 2.��

The mobile station shall negotiate for Service Option 35 using service negotiation (see��

3.2.2.3.2.1).��

The mobile station shall negotiate for Service Option 36 using service negotiation (see��

3.2.2.3.2.1).��

3.2.2.3.2.1 Procedures Using Service Negotiation��

The mobile station shall perform service negotiation for Service Option 35 or Service Option��

36 as described in TIA/EIA-95-B. The negotiated service configuration shall include only��

valid attributes for the negotiated service option consistent with those specified in Table��

3.2.2.3.2.1-1 and Table 3.2.2.3.2.1-2.��

��

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Table 3.2.2.3.2.1-1. Valid Service Configuration Attributes for Service Option 35�

Service Configuration Attribute Valid Selections

Forward Multiplex Option Multiplex Option 1

Reverse Multiplex Option Multiplex Option 1

Forward Transmission Rates Rate Set 1 with all four rates enabled

Reverse Transmission Rates Rate Set 1 with all four rates enabled

Forward Traffic Type None. This service option does not use norgenerate any forward traffic other than signaling.

Reverse Traffic Type None. This service option does not use norgenerate any reverse traffic other than signaling.

�

Table 3.2.2.3.2.1-2. Valid Service Configuration Attributes for Service Option 36�

Service Configuration Attribute Valid Selections

Forward Multiplex Option Multiplex Option 2

Reverse Multiplex Option Multiplex Option 2

Forward Transmission Rates Rate Set 2 with all four rates enabled

Reverse Transmission Rates Rate Set 2 with all four rates enabled

Forward Traffic Type None. This service option does not use norgenerate any forward traffic other than signaling.

Reverse Traffic Type None. This service option does not use norgenerate any reverse traffic other than signaling.

�

If the mobile station accepts a service configuration, as specified in a Service Connect�

Message, that includes a service option connection using Service Option 35 or Service�

Option 36, then the service option connection shall become part of the current service�

configuration at the action time associated with the Service Connect Message. Service�

Option 35 or Service Option 36 is considered to be connected when the current service�

configuration includes a service option connection for it.��

If Service Option 35 or Service Option 36 is connected when the mobile station enters the��

Waiting for Mobile Station Answer Substate, or Service Option 35 or Service Option 36��

becomes connected while the mobile station is in the Waiting for Mobile Station Answer��

Substate, the mobile station shall send a Connect Order to the base station as a message��

requiring acknowledgment without waiting for the user to explicitly command the call to be��

answered. The mobile station shall enter the Conversation Substate.��

The mobile station shall not send a Service Option Control Message for Service Option 35 or��

Service Option 36. The mobile station shall send a Mobile Station Reject Order (ORDQ =��

TIA/EIA/IS-801

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‘00000001’, unspecified reason), if it receives a Service Option Control Message for Service�

Option 35 or Service Option 36 from the base station.�


A mobile station supporting Position Determination shall accept and shall process Data�

Burst Messages received on the CDMA Forward Traffic Channel (see 7.7.2.3.2.9 of�

TIA/EIA-95-B). Processing of TIA/EIA-95-B Layer-2 fields shall be in accordance with�

TIA/EIA-95-B. Data Burst Messages used to transport Position Determination request and�

response elements shall always be acknowledged (Layer 2) and the in-order delivery over�

the air interface shall be guaranteed by the transmitting entities: Mobile station and base�

station.��

The mobile station shall process all Data Burst Messages addressed to the mobile station��

on the Forward Traffic Channel and having the BURST_TYPE field set to ‘000101’ (as��

assigned in TSB58-B). The mobile station shall discard the message without further��

processing if one or more of the following is true:��




Otherwise, the mobile station shall process the Position Determination Data contained in��

the CHARi fields of the received Data Burst Message (see 7.7.3.3.2.4 of TIA/EIA-95-B), as��


3.2.2.3.3.1 Base Station Request Elements Received��

If the mobile station is unable to respond with the requested information, the mobile��

station shall respond with a “Reject” response element with the appropriate reject reason,��

unless the base station request element is “Request MS Information” or “Request��

Cancellation” (these request elements cannot be rejected); otherwise, the mobile station��

shall include the appropriate response elements in the response Position Determination��

Data (see 3.2.4) as described below. The response Position Determination Data shall reside��

in the CHARi fields of the response Data Burst Message (see 6.7.2.3.2.4 of TIA/EIA-95-B).7��

• Request MS Information: The mobile station shall include the “Provide MS��

Information” response element in the response Position Determination Data. The��

response Position Determination Data Message shall be sent within 750 ms of the��

reception of the “Request MS Information”.��

• Request Autonomous Measurement Weighting Factors: The mobile station shall��

include the “Provide Autonomous Measurement Weighting Factors” response��

element in the response Position Determination Data. The PREF_RESP_QUAL��

indicator provided in the “Request Location Response” shall also apply to the��

“Request Autonomous Measurement Weighting Factors” request element.��


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• Request Pseudorange Measurement: The mobile station shall send one or more�

“Provide Pseudorange Measurement” response elements, according to that which is�


Fixes) included in the “Request Pseudorange Measurement”. The mobile station�

shall include the “Provide Pseudorange Measurement” response element in one or�

more response Position Determination Data Messages according to the number of�

parts into which the response element is divided. The mobile station should use the�

mobile station time reference as defined in TIA/EIA-95 as the time reference used to�

perform the pseudorange measurements.8 If the mobile station is unable to use the�

mobile station time reference as defined in TIA/EIA-95 to measure the��

pseudoranges, then the mobile station shall use an alternate time reference to��

perform the pseudorange measurements. The mobile station shall set the��

TIME_REF_SRC field in the “Provide Pseudorange Measurement” response element��

to the appropriate value to indicate the source of the time reference used to perform��

the pseudorange measurements. The mobile station shall set the periodic rate of��


² If PREF_RESP_QUAL is set to ‘000’, the “Provide Pseudorange Measurement”��



is set to ‘001’, the “Provide Pseudorange Measurement” response element��

shall be sent within T2 seconds of the time corresponding to the beginning of��

the measurement collection period; if PREF_RESP_QUAL is set to ‘010’, the��

“Provide Pseudorange Measurement” response element shall be sent within��

T3 seconds of the time corresponding to the beginning of the measurement��
















collection period.��

8 The time reference used to perform the pseudorange measurements should be initializedfrom the mobile station time reference as defined in TIA/EIA-95.

TIA/EIA/IS-801

3-15

² If OFFSET_REQ is set to ‘1’, the “Provide Pseudorange Measurement”�

response element shall include REF_PN and MOB_SYS_T_OFFSET;�

otherwise the “Provide Pseudorange Measurement” response element should�

not include REF_PN and MOB_SYS_T_OFFSET.�

• Request Pilot Phase Measurement: The mobile station shall send one or more�

“Provide Pilot Phase Measurement” response elements, according to that which is�


Fixes) included in the “Request Pilot Phase Measurement”. The mobile station shall�

include the “Provide Pilot Phase Measurement” response element in one or more�

response Position Determination Data Messages according to the number of parts��

into which the response element is divided. The mobile station shall set the periodic��

rate of measurement collection equal to the value of T_BETW_FIXES.��

² If PREF_RESP_QUAL is set to ‘000’, the “Provide Pilot Phase Measurement”��










time corresponding to the beginning of the measurement collection period; if��

PREF_RESP_QUAL is set to ‘100’, the “Provide Pilot Phase Measurement”��










time corresponding to the beginning of the measurement collection period.��

² If DESI_PIL_PH_RES is set to ‘1’, the “Provide Pilot Phase Measurement”��

response element shall9 be of at least 1/8 of TIA/EIA-95 PN chip resolution;��

otherwise, the “Provide Pilot Phase Measurement” response element shall be��

of at least 1 TIA/EIA-95 PN chip resolution.��

² If OFFSET_REQ is set to ‘1’, the “Provide Pilot Phase Measurement” response��

element shall include MOB_SYS_T_OFFSET; otherwise the “Provide Pilot��

9 If the mobile station rejects the request with 1/8 chip resolution, it may send anunsolicited response (see 3.2.1.1) with 1 chip resolution.

TIA/EIA/IS-801

3-16

Phase Measurement” response element should not include�

MOB_SYS_T_OFFSET.�

• Request Location Response: The mobile station shall send one or more “Provide�

Location Response” response elements, according to that which is specified by�

NUM_FIXES (Number of Fixes) and T_BETW_FIXES (Time between Fixes) included�

in the “Request Location Response”. The mobile station shall include the “Provide�

Location Response” response element in one or more response Position�

Determination Data Messages according to the number of parts into which the�

response element is divided. The mobile station shall set the periodic rate of�


² If PREF_RESP_QUAL is set to ‘000’, the “Provide Location Response”��



is set to ‘001’, the “Provide Location Response” response element shall be��

sent within T2 seconds of the time corresponding to the beginning of the��






corresponding to the beginning of the measurement collection period; if��

PREF_RESP_QUAL is set to ‘100’, the “Provide Location Response” response��

element shall be sent within T5 seconds of the time corresponding to the��

beginning of the measurement collection period; if PREF_RESP_QUAL is set��

to ‘101’, the “Provide Location Response” response element shall be sent��

within T6 seconds of the time corresponding to the beginning of the��






corresponding to the beginning of the measurement collection period.��

² If HEIGHT_REQ is set to ‘1’, the “Provide Location Response” response��

element should include height information; otherwise, the “Provide Location��

Response” response element should not include height information.��


element should include clock correction for GPS time; otherwise, the “Provide��

Location Response” response element should not include clock correction for��

GPS time.��

² If VELOCITY_REQ is set to ‘1’, the “Provide Location Response” response��

element should include velocity information; otherwise, the “Provide Location��

Response” response element should not include velocity information.��

TIA/EIA/IS-801

3-17

• Request Time Offset Measurement: The mobile station shall include a “Provide Time�

Offset Measurement” response element in the response Position Determination�

Data. If USE_TIME is set to ‘1’, the “Provide Time Offset Measurement” response�

element shall include the offset information determined to be valid at the�

ACTION_TIME. If USE_TIME is set to ‘0’, the “Provide Time Offset Measurement”�

response element shall include the offset information determined to be valid at the�

time the “Request Time Offset Measurement” is received by the mobile station. If�

USE_TIME is set to ‘1’, the “Provide Time Offset Measurement” response element�

shall be sent within 750 ms of ACTION_TIME. If USE_TIME is set to ‘0’, the “Provide�

Time Offset Measurement” response element shall be sent within 750 ms of the��

reception of the “Request Time Offset Measurement” request element.��

• Request Cancellation: The mobile station shall cancel the outstanding request��

element indicated by CANCEL_TYPE. The mobile station shall include a “Provide��

Cancellation Acknowledgement” response element in the Position Determination Data��

Message to indicate the successful cancellation of the outstanding request element.��

If the mobile station has no outstanding request element of the type indicated by��

CANCEL_TYPE, it shall set the NO_OUT_REQ flag in the “Provide Cancellation��

Acknowledgment” response element. The “Provide Cancellation Acknowledgement”��

response element shall be sent within 750 ms of the reception of the “Request��

Cancellation” request element.��

3.2.2.3.3.2 Base Station Response Elements Received��

The mobile station should process and should make use of base station response elements.��

Upon receiving a Position Determination Data Message, the mobile station should examine��

the received response elements prior to processing the request elements.��

If the mobile station receives “Provide GPS Almanac Correction” response element, the��

mobile station shall process the response element as follows.��

• If DELTA_XYZ_INCL is ‘0’, the mobile station shall set the values of DELTA_X,��

DELTA_Y, DELTA_Z, DELTA_X_1ST, DELTA_Y_1ST and DELTA_Z_1ST to 0.��

• If DELTA_CLOCK_INCL is ‘0’, the mobile station shall set the values of��

DELTA_CLOCK and DELTA_CLOCK_1ST to 0.��

3.2.2.3.4 Traffic Channel Setup��

When a mobile station in the TIA/EIA-95-B Mobile Station Idle State intends to send��

Position Determination Data Message on a Traffic Channel, the following procedures apply:��

• The mobile station shall send an Origination Message (see 6.7.1.3.2.4 of��

TIA/EIA-95-B) containing no dialed digits and requesting Service Option 35 or��

Service Option 36. The base station should complete an authentication Unique��

Challenge-Response Procedure (see 6.3.12.1.5 of TIA/EIA-95-B) immediately after��

assigning the traffic channel. The Unique Challenge-Response Procedure should be��

completed successfully before the Position Determination Data Messages are sent to��

the mobile station, and before the mobile-originated Position Determination Data��

Messages are forwarded to other network entities.��

TIA/EIA/IS-801

3-18

• Call processing following the transmission of the Origination Message shall follow�

the procedures defined in 6.6 of TIA/EIA-95-B. When the mobile station enters the�

Conversation Substate, the mobile station may send the Position Determination Data�

Messages in accordance with the procedures defined in the next section.�

3.2.2.3.5 Mobile Position Message Origination in the Conversation Substate�

3.2.2.3.5.1 Position Determination Data Message Transmission Requirements�

When the mobile station is in the TIA/EIA-95-B Mobile Station Conversation Substate and�

needs to send one (or more) Position Determination Data Message(s), the mobile station shall�

form one (or more) Data Burst Message(s) (see 6.7.2.3.2.4 of TIA/EIA-95-B), setting�

BURST_TYPE to ‘000101’ and send the Data Burst Message(s) on the Reverse Traffic��

Channel. The mobile station shall set the MSG_NUMBER and NUM_MSGS fields to 1, and��

shall set NUM_FIELDS field to the number of octets in the Position Determination Data��

Message (see 3.2.4). The Data Burst Message contains the Position Determination Data in��

the CHARi fields (see 6.7.2.3.2.4 of TIA/EIA-95-B). The mobile station shall set the��

ACK_REQ Layer-2 field to ‘1’. If the only connected service option is Service Option 35 or��

Service Option 36, the mobile station should enter the Release Substate with a mobile��

station release indication (see 6.6.4.5 of TIA/EIA/95-B) when Position Determination Data��

Messages have not been received or have not been sent during a period of time which is��

implementation-dependent. If any service option in addition to Service Option 35 or Service��

Option 36 is connected, the mobile station shall remain in the Conversation Substate, and��

the mobile station should initiate Service Negotiation to drop Service Option 35 or Service��

Option 36 when Position Determination Data Messages have not been received or have not��

been sent during a period of time which is implementation-dependent. If the user needs to��

initiate a call and Service Option 35 or 36 is the only service option connected, then the��

mobile station should release the call for Service Option 35 or 36 if needed to connect the��

user call.��


Reserved��


Reserved��

3.2.3 Broadcast Procedures��

Reserved��

3.2.4 Reverse Link Message Format��

The reverse link Position Determination Data Messages are summarized in Table 3.2.4-1.��

��

TIA/EIA/IS-801

3-19

Table 3.2.4-1. Reverse Link Messages�

Message Name PD_MSG_TYPE

Position Determination DataMessage

‘00000000’

Reserved for future standardization ‘00000001’ through‘10111111’

Available for manufacturer-specificPosition Determination DataMessage definition as specified inTSB-58

‘11000000’ through‘11111110’

Reserved ‘11111111’

�

The Position Determination Data Message from mobile station to base station has the�

following variable length format:�

�

Field Length (bits)

SESS_START 1

SESS_END 1

SESS_SOURCE 1

SESS_TAG 5

PD_MSG_TYPE (‘00000000’) 8

NUM_REQUESTS 4

NUM_RESPONSES 4

The mobile station shall include NUM_REQUESTSoccurrences of the following record:

RESERVED 4

REQ_TYPE 4

REQ_PAR_LEN 8

REQ_PAR_RECORD 8 × REQ_PAR_LEN

The mobile station shall include NUM_RESPONSESoccurrences of the following record:

TIA/EIA/IS-801

3-20

RESERVED 3

UNSOL_RESP 1

RESP_TYPE 4

RESP_PAR_LEN 8

RESP_PAR_RECORD 8 × RESP_PAR_LEN

�

SESS_START – Start-of-session indicator.�

If the mobile station has previously sent or received a�

Position Determination Data Message related to this�

Position Determination Data Message (as defined in�

2.2.1) it shall set this field to ‘0’; otherwise, it shall set�

this field to ‘1’.�

SESS_END – End-of-session indicator.�

If the mobile station does not expect to receive or send�

any more Position Determination Data Messages related��

to this Position Determination Data Message (as defined��

in 2.2.1) the mobile station shall set this field to ‘1’;��

otherwise, it shall set this field to ‘0’. The criteria for��

setting this field are implementation dependent.��

SESS_SOURCE – Session-source indicator.10��

If SESS_START is set to ‘1’ the mobile station shall set��

this field to ‘1’; otherwise it shall set this field to the��

same value as the SESS_SOURCE field that appeared��

in a previously-received or previously-sent Position��

Determination Data Message that was related to this��

Position Determination Data Message (as defined in��

2.2.1).��

10 This field indicates which side (mobile station or base station) initiated this session.

TIA/EIA/IS-801

3-21

SESS_TAG – Session tag.�

If SESS_START is set to ‘0’ the mobile station shall set�

this field to the same value as the SESS_TAG field that�

appeared in a previously-received or previously-sent�

Position Determination Data Message that was related�

to this Position Determination Data Message (as defined�

in 2.2.1); otherwise, the mobile station shall set this�

field to one more (modulo 32) than the value it�

assigned to this field in the latest Position�

Determination Data Message that it sent with��

SESS_START set to ‘1’. If no such latest Position��

Determination Data Message exists, the mobile station��

shall set this field to ‘00000’. The definition of “latest”��

is implementation dependent.��

PD_MSG_TYPE – Position Determination Data Message type.��

The mobile station shall set this field to ‘00000000’.��

NUM_REQUESTS – Number of request element parameter records.��

The mobile station shall set this field to the number of��

request element parameters records included in the��

message.��

NUM_RESPONSES – Number of response element parameter records.��


response element parameters records included in the��

message.��

RESERVED – Reserved bits.��


REQ_TYPE – Request element type.��

The mobile station shall set this field to the value��

shown in Table 3.2.4-2.��

��

TIA/EIA/IS-801

3-22

Table 3.2.4-2. Request Element Type�

Description REQ_TYPE(binary)

Reserved ‘0000’

Request BS Capabilities ‘0010’

Request GPS Acquisition Assistance ‘0100’

Request GPS Location Assistance ‘0110’

Reserved ‘0111’

Request GPS Sensitivity Assistance ‘0101’

Request Base Station Almanac ‘0011’

Request GPS Almanac ‘1000’

Request GPS Ephemeris ‘1001’

Request GPS Navigation Message Bits ‘1010’

Request Location Response ‘0001’

Request GPS Almanac Correction ‘1011’

All other REQ_TYPE values are reserved.

�

REQ_PAR_LEN – Request element parameters length.�

The mobile station shall set this field to the number of�

octets included in the REQ_PAR_RECORD field.�

REQ_PAR_RECORD – Request element parameters record.�

The mobile station shall set this record as described in�

3.2.4.1.�

RESERVED – Reserved bits.�

The mobile station shall set these bits to ‘000’.��

UNSOL_RESP – Unsolicited response indicator.��

If the response element is an unsolicited response��

element, the mobile station shall set this field to ‘1’;��

otherwise the mobile station shall set this field to ‘0’.��

RESP_TYPE – Response element type.��


shown in Table 3.2.4-3.��

��

TIA/EIA/IS-801

3-23

Table 3.2.4-3. Response Element Type�

Description RESP_TYPE(binary)

Reject ‘0000’

Provide MS Information ‘0010’

Provide Autonomous Measurement Weighting Factors ‘0011’

Provide Pseudorange Measurement ‘0100’

Provide Pilot Phase Measurement ‘0101’

Provide Location Response ‘0001’

Provide Time Offset Measurement ‘0110’

Provide Cancellation Acknowledgement ‘0111’

All other RESP_TYPE values are reserved.

�

RESP_PAR_LEN – Response element parameters length.�

The mobile station shall set RESP_PAR_LEN to the�

number of octets included in the response element.�

RESP_PAR_RECORD – Response element parameters record.�

The mobile station shall set this record as described in�

3.2.4.2.�

3.2.4.1 Request Element Parameters Record�

The mobile station shall set REQ_PAR_RECORD as described below11.��

If REQ_TYPE in Position Determination Data Message is equal to ‘0010’, or if REQ_TYPE is��

equal to ‘0101’, or if REQ_TYPE is equal to ‘1000’, the mobile station shall not include this��

record. If REQ_TYPE in Position Determination Data Message is equal to ‘0001’, or if��

REQ_TYPE is equal to ‘0011’, or if REQ_TYPE is equal to ‘0100’, or if REQ_TYPE is equal to��

‘0110’, or if REQ_TYPE is equal to ‘1001’, or if REQ_TYPE is equal to ‘1010’, or if REQ_TYPE��

is equal to ‘1011’, the mobile station shall include the record REQ_PAR_RECORD and set��

its fields as described below.��

If REQ_TYPE is equal to ‘0100’ (Request GPS Acquisition Assistance), REQ_PAR_RECORD��

shall include the following record:��

11 A request element includes any parameters that directly specify the structure or contentsof the expected response. It does not include parameters that convey information about the"state" (or status) of the mobile, or values of parameters stored in the mobile. If suchparameters are needed in support of the request, they can be conveyed in an unsolicitedresponse. (Note: "state" does not refer to the IS-95 state of the mobile; rather, it refers, ingeneral, to the internal status of the mobile).

TIA/EIA/IS-801

3-24

�

Field Length (bits)

DOPP _REQ 1

ADD_DOPP_REQ 1

CODE_PH_PAR_REQ 1

AZ_EL_REQ 1

RESERVED 4

�

DOPP _REQ – Doppler (0th order) term requested.�

If Doppler (0th order) terms are requested, the mobile�

station shall set this field to ‘1’; otherwise the mobile�

station shall set this field to ‘0’.�

ADD_DOPP_REQ – Additional Doppler terms requested.�

If the Doppler (0th order) terms, the Doppler High-�

Order terms and the Doppler search window terms are�

requested, the mobile station shall set this field to ‘1’;��


CODE_PH_PAR_REQ – Code phase parameters requested.��

If the code phase parameters are requested, the mobile��

station shall set this field to ‘1’; otherwise the mobile��

station shall set this field to ‘0’.��

AZ_EL_REQ – Azimuth and elevation angle requested.��

If azimuth and elevation angle are requested, the��

mobile station shall set this field to ‘1’; otherwise the��

mobile station shall set this field to ‘0’.��



If REQ_TYPE is equal to ‘0110’ (Request GPS Location Assistance), REQ_PAR_RECORD��


��

Field Length (bits)

COORD_TYPE 1

RESERVED 7

��

COORD_TYPE – Coordinate type requested.��

TIA/EIA/IS-801

3-25

If Cartesian coordinates are requested, the mobile�

station shall set this field to ‘0’. If spherical�

coordinates are requested, the mobile station shall set�



The mobile station shall set this field to ‘0000000’.�

If REQ_TYPE is equal to ‘0011’ (Request Base Station Almanac), REQ_PAR_RECORD shall�

include the following record:�

�

Field Length (bits)

EXT_BS_ALM 1

RESERVED 7

��

EXT_BS_ALM – Extended base station almanac requested.��

If the extended base station almanac is requested, the��

mobile station shall set this field to ‘1’. If the base��

station almanac is requested, the mobile station shall��

set this field to ‘0’.��



If REQ_TYPE is equal to ‘1001’ (Request GPS Ephemeris), REQ_PAR_RECORD shall include��

the following record:��

��

Field Length (bits)

AB_PAR_REQ 1

RESERVED 7

��

AB_PAR_REQ – Alpha/Beta parameters requested.��

If Alpha/Beta parameters are requested, the mobile��

station shall set this field to ‘1’; otherwise the mobile��

station shall set this field to ‘0’.��



If REQ_TYPE is equal to ‘1010’ (Request GPS Navigation Message Bits), REQ_PAR_RECORD��


��

TIA/EIA/IS-801

3-26

Field Length (bits)

SUBF_4_5_REQ 1

RESERVED 7

�

SUBF_4_5_REQ – Subframes 4 and 5 requested.�

If subframes 4 and 5 are requested, the mobile station�

shall set this field to ‘1’; otherwise the mobile station�

shall set this field to ‘0’.�



If REQ_TYPE is equal to ‘0001’ (Request Location Response), REQ_PAR_RECORD shall�


��

Field Length (bits)

HEIGHT_REQ 1

CLK_COR_GPS_REQ 1

VELOCITY_REQ 1

RESERVED 5

��

HEIGHT_REQ – Height information requested.��

If height information is requested, the mobile station��

shall set this field to ‘1’; otherwise the mobile station��

shall set this field to ‘0’.��

CLK_COR_GPS_REQ – Clock correction for GPS time requested.��

If clock correction for GPS time is requested, the��

mobile station shall set this field to ‘1’; otherwise the��

mobile station shall set this field to ‘0’.��

VELOCITY_REQ – Velocity information requested.��

If velocity information is requested, the mobile station��





If REQ_TYPE is equal to ‘1011’ (Request GPS Almanac Correction), REQ_PAR_RECORD��


TIA/EIA/IS-801

3-27

�

Field Length (bits)

TOA 8

WEEK_NUM 8

�

TOA – Time of almanac.�

The mobile station shall set this field to the time of�

applicability of the almanac for which the correction is�

requested, in units of 4096 s, in the range from 0 to�

602,112 s.�

WEEK_NUM – GPS week number.�

The mobile station shall set this field to the 8 least�

significant bits of the GPS week number of the��

almanac for which the correction is requested. The��

range for this field is from 0 to 255.��

3.2.4.2 Response Element Parameters Record��

The mobile station shall set RESP_PAR_RECORD as described below.��

If RESP_TYPE in Position Determination Data Message is equal to ‘0000’ (Reject),��

RESP_PAR_RECORD shall include the following record:��

��

Field Length (bits)

REJ_REQ_TYPE 4

REJ_REASON 3

RESERVED 1

��

REJ_REQ_TYPE – Reject request type.��

The mobile station shall set this field to the value of��

the REQ_TYPE corresponding to the request element it��

rejects. See Table 4.2.4-2.��

REJ_REASON – Reject reason.��


shown in Table 3.2.4.2-1.��

��

TIA/EIA/IS-801

3-28

Table 3.2.4.2-1. Reject Reason�

Reason for rejectionREJ_REASON

(binary)

Capability not supported by the mobile station ‘000’

Capability normally supported by the mobilestation but temporarily not available or notenabled12

‘001’

All other REJ_REASON values are reserved.

�



If RESP_TYPE is equal to ‘0010’ (Provide MS Information), RESP_PAR_RECORD shall�

include the following variable-length record:�

�

Field Length (bits)

MS_LS_REV 6

MS_MODE 4

PILOT_PH_CAP 6

GPS_ACQ_CAP 12

LOC_CALC_CAP 12

�

MS_LS_REV – The mobile station location standard revision number.�


MS_MODE – The digital mode indicator.��


PILOT_PH_CAP – Pilot phase capability.��


shown in Table 3.2.4.2-2.��

��

12 For example, the position determination feature may be disabled by the user.

TIA/EIA/IS-801

3-29

Table 3.2.4.2-2. Pilot Phase Capability�

PILOT_PH

(binary)

IS-95 Pilot Phase Capability

‘000000’ Full Chip Measurement Capability

‘000001’ Half Chip Measurement Capability

‘000010’ Quarter Chip Measurement Capability

‘000011’ Eighth Chip Measurement Capability

‘000100’ One Sixteenth Chip Measurement Capability

All other PILOT_PH values are reserved.

�

GPS_ACQ_CAP – GPS acquisition capability.�

GPS_ACQ_CAP consists of 12 bits, each of the LSB’s�

represents one GPS acquisition capability. The�

mapping of the bits is listed in Table 3.2.4.2-3. If a�

GPS acquisition capability is supported, the mobile�

station shall set the corresponding bit in�

GPS_ACQ_CAP to ‘1’; otherwise the mobile station�

shall set the corresponding bit to ‘0’. Bits 8-12 shall��

be set to ‘00000’.��

��

Table 3.2.4.2-3. Mapping Table for GPS Acquisition Capability��

Corresponding Bit in GPS_ACQ_CAP GPS Acquisition Capability

Bit 1 (LSB) GPS Acquisition Assistance

Bit 2 GPS Sensitivity Assistance

Bit 3 GPS Almanac

Bit 4 GPS Ephemeris

Bit 5 GPS Navigation Message Bits

Bit 6 GPS Almanac Correction

Bit 7 GPS Autonomous Acquisition Capable

Bits 8 – 12 Reserved

��

LOC_CALC_CAP – Position calculation capability.��

TIA/EIA/IS-801

3-30

LOC_CALC_CAP consists of 12 bits, each of the LSB’s�

represents one position calculation capability. The�

mapping of the bits is listed in Table 3.2.4.2-4. If a�

position calculation capability is supported, the mobile�

station shall set the corresponding bit in�

LOC_CALC_CAP to ‘1’; otherwise the mobile station�

shall set the corresponding bit to ‘0’. Bits 9-11 shall�

be set to ‘000’.�

�

Table 3.2.4.2-4. Mapping Table for Position Calculation Capability��

Corresponding Bit in LOC_ACQ_CAP Position Calculation Capability

Bit 1 (LSB) Location Calculation Capable usingLocation Assistance – Spherical

Bit 2 Location Calculation Capable usingLocation Assistance – Cartesian

Bit 3 Advanced Forward Link Trilateration(AFLT) Location Calculation Capable

Bit 4 Location Calculation Capable using GPSAlmanac Assistance

Bit 5 Location Calculation Capable using GPSEphemeris Assistance

Bit 6 Location Calculation Capable using GPSAlmanac Correction

Bit 7 Autonomous Location Calculation Capable

Bit 8 Hybrid GPS and AFLT LocationCalculation Capable

Bit 9 –11 Reserved

Bits 12 (MSB) Pre-programmed Location

��

If RESP_TYPE is equal to ‘0011’ (Provide Autonomous Measurement Weighting Factors),��

RESP_PAR_RECORD shall include the following variable length record:��

��

TIA/EIA/IS-801

3-31

Field Length (bits)

TIME_REF_CDMA 14

DGPS 1

NUM_SV 4

GPS_WEIGHT 4

The mobile station shall include NUM_SV occurrences of thefollowing fields:

SV_PRN_NUM 6

INV_WEIGHT_FA 6

RESERVED 0 - 7 (as needed)

�

TIME_REF_CDMA – CDMA system time at the time the solution is valid.�

The mobile station shall set this field to (t/50 mod�

16384), where t is the CDMA system time in frames, as�

defined in 1.2 of TIA/EIA-95-B, at the time the�

solution is valid. This is the time at which the values�

of the parameters reported in this response element�

parameter record are valid.�

DGPS – DGPS flag.�

If differential GPS is used, the mobile station shall set��

this field to ‘1’; otherwise the mobile station shall set��

this field to ‘0’.��

NUM_SV – Number of GPS satellites in solution.��


GPS satellites used to compute the solution, in the��

range from 1 to 16, where the binary value of the field��

conveys the number of satellites minus one.��

GPS_WEIGHT – Ratio of GPS weight to total weight.��

The mobile station shall set this field to the ratio of��

GPS weight to total weight (GPS weight and pilot phase��

weight) used to compute the solution, in the range��

from 0 to 1, with a resolution of 1/15.��

TIA/EIA/IS-801

3-32

SV_PRN_NUM – Satellite PRN number.�

The mobile station shall set this field to the value of�

the PRN signal number for which the measured data is�

valid. It is represented as an unsigned value in the�

range from 1 to 37, where the binary value of the field�

conveys the satellite PRN number minus one.�

INV_WEIGHT_FA – Inverse of weighting factor.�

The mobile station shall set this field to the inverse of�

the weighting factor used for the satellite, in the range�

from 0.5 m to 112 m. A “floating-point” representation��

is used where the 3 most significant bits constitute the��

exponent and the 3 least significant bits constitute the��

mantissa as specified in Table 3.2.4.2-5.��

��

Table 3.2.4.2-5. Inverse of Weighting Factor Representation��

Exponent, X Mantissa, YIndex value, i

= Y + 8 × XFloating-Point

value, fi

Inverse WeightingFactor value, σ (m)

‘000’ ‘000’ 0 0.5 σ < 0.5

‘000’ ‘001’ 1 0.5625 0.5 ≤ σ < 0.5625

X Y 2 ≤ i ≤ 61 0.5×(1 + Y/8)×2X fi-1 ≤ σ < fi

‘111’ ‘110’ 62 112 104 ≤ σ < 112

‘111’ ‘111’ 63 Not Applicable 112 ≤ σ

��


The mobile station shall add reserved bits as needed in��

order to make the length of the response element��

parameters record equal to an integer number of��

octets. The mobile station shall set these bits to ‘0’.��

TIA/EIA/IS-801

3-33

If RESP_TYPE is equal to ‘0100’ (Provide Pseudorange Measurement), RESP_PAR_RECORD�

shall include the following variable length record:�

�

Field Length (bits)

PART_NUM 3

TOTAL_PARTS 3

NUM_PS_RANGES_P 6

TIME_REF 24

TIME_REF_SRC 2

OFFSET_INCL 1

REF_PN 0 or 9

MOB_SYS_T_OFFSET 0 or 14

The mobile station shall include NUM_PS_RANGES_Poccurrences of the following fields:

SV_PRN_NUM 6

SV_CNO 6

PS_DOPPLER 16

SV_CODE_PH_WH 10

SV_CODE_PH_FR 10

MUL_PATH_IND 3

PS_RANGE_RMS_ER 6


�

PART_NUM – The part number.�

The mobile station shall set this field to specify the�

part number of the Pseudorange Measurement data, in�

the range from 1 to TOTAL_PARTS.�

TOTAL_PARTS – The total number of parts.�

The mobile station shall set this field to specify the��

total number of parts that the Pseudorange��

Measurement data is divided into, in the range from 1��

to 8.��

TIA/EIA/IS-801

3-34

NUM_PS_RANGES_P – Number of pseudoranges in this part.�

The mobile station shall set this field to the number of�

pseudoranges included in this part of the response�

element, in the range from 1 to 64, where the binary�

value of the field conveys the number of satellites�

minus one.�

TIME_REF – The time of validity of the parameters reported in this�

response element.�

The mobile station shall set this field to�

(t mod 14,400,000), where t is the time of validity in��

units of 1 ms, based on the time reference specified by��

TIME_REF_SRC (see Table 3.2.4.2-6). This is the time��

at which the values of the parameters reported in this��

response element parameter record are valid.��

TIME_REF_SRC – Time reference source.��

The mobile station shall set this field according to��

Table 3.2.4.2-6.��

��

Table 3.2.4.2-6. Time Reference Source��

Time reference sourceTIME_REF_SRC

(binary)

Mobile station time reference as defined in 6.1.5.1 ofTIA/EIA-95-B

‘00’

GPS time reference ‘01’

Other time reference ‘10’

Reserved ‘11’

��

OFFSET_INCL – Offset Included.��

If the response element includes REF_PN and��

MOB_SYS_T_OFFSET fields, then the mobile station��



REF_PN – Time reference PN sequence offset.��

If the OFFSET_INCL field is set to ‘1’, then the mobile��

station shall set this field to the PN sequence offset of��

the pilot used by the mobile station to derive its time��

reference, relative to the zero offset pilot PN sequence��

in units of 64 PN chips; otherwise the mobile station��

shall not include this field.��

TIA/EIA/IS-801

3-35

MOB_SYS_T_OFFSET – Mobile station system time offset.�

If the OFFSET_INCL field is set to ‘1’, then the mobile�

station shall set this field to the two’s complement�

value of the offset between mobile station time�

reference and time of occurrence of Reference PN, in�

units of 1/16 TIA/EIA-95-B chips13, in the range from�

-512 to +511.9375 TIA/EIA-95-B chips; otherwise the�

mobile station shall not include this field. The sign of�

this quantity shall be positive if the reference PN�

occurs earlier than the mobile station time reference;��

otherwise it shall be negative.��

SV_PRN_NUM – Satellite PRN number.��


the PRN signal number for which the measured data is��

valid. It is represented as an unsigned value in the��


conveys the satellite PRN number minus one.��

SV_CNO – Satellite C/N0.��


the satellite C/N0, as referenced to the antenna��

connector14, in units of 1 dB-Hz, in the range from 0 to��

63 dB-Hz.��

PS_DOPPLER – Pseudodoppler.��

The mobile station shall set this field to the two’s��

complement value of the measured satellite��

pseudodoppler, in units of 0.2 Hz, in the range from��

-6,553.6 Hz to +6,553.6 Hz.��

SV_CODE_PH_WH – Satellite code phase – whole chips.��

The mobile station shall set this field to the satellite��

code phase measured as a number of GPS chips, in��

units of 1 GPS chips, in the range from 0 to 1022��

chips.��

13 This field supports a maximum resolution of 1/16th of a TIA/EIA-95-B chip. However,mobile stations not capable of 1/16th chip measurement resolution are also supported bythis standard (See Table 3.2.4.2-2). Measurements made at lower resolutions are reportedin this field using 1/16th chip resolution.

14 If an active antenna is employed (i.e., one with a built-in amplifier and/or filter), thenC/N0 should be referenced to the antenna port prior to any amplifier or filter.

TIA/EIA/IS-801

3-36

SV_CODE_PH_FR – Satellite code phase – fractional chips.�

The mobile station shall set this field to the residual�

satellite code phase, in units of 1/210

of GPS chips, in�

the range from 0 to (210

-1)/210

GPS chips.�

MUL_PATH_IND – Multipath indicator.�

The mobile station shall set this field to the value�

shown in Table 3.2.4.2-7.�

�

Table 3.2.4.2-7. Multipath Indicator�

DescriptionThreshold MUL_PATH_IND

(binary)

Not measured Not specified ‘000’

Low MP Error ≤ 5 m ‘001’

Medium 5 m < MP Error ≤ 43 m ‘010’

High MP Error > 43 m ‘011’

All other MUL_PATH_IND values are reserved.

��

PS_RANGE_RMS_ER – Pseudorange RMS error.��

The mobile station shall set this field to the��

pseudorange RMS error used for the satellite, in the��

range from 0.5 m to 112 m. A “floating-point”��

representation is used where the 3 most significant��

bits constitute the exponent and the 3 least significant��

bits constitute the mantissa as specified in Table��

3.2.4.2-8.��

��

Table 3.2.4.2-8. Pseudorange RMS Error Representation��


= Y + 8×XFloating-Point

value, fi

Pseudorange value,P (m)

‘000’ ‘000’ 0 0.5 P < 0.5

‘000’ ‘001’ 1 0.5625 0.5 ≤ P < 0.5625

X Y 2 ≤ i ≤ 61 0.5×(1 + Y/8)×2X fi-1 ≤ P < fi

‘111’ ‘110’ 62 112 104 ≤ P < 112

‘111’ ‘111’ 63 Not Applicable 112 ≤ P

��

TIA/EIA/IS-801

3-37


The mobile station shall add reserved bits as needed in�

order to make the length of the response element�

parameters record equal to an integer number of�

octets. The mobile station shall set these bits to ‘0’.�

TIA/EIA/IS-801

3-38

If RESP_TYPE is equal to ‘0101’ (Provide Pilot Phase Measurement), RESP_PAR_RECORD�

shall include the following variable length record:�

�

Field Length (bits)

TIME_REF_MS 24

OFFSET_INCL 1

MOB_SYS_T_OFFSET 0 or 14

REF_PN 9

PILOT_STRENGTH 6

BAND_CLASS 5

CDMA_FREQ 11

BASE_ID 16

SID 15

NID 16

PART_NUM 3

TOTAL_PARTS 3

NUM_PILOTS_P 6

The mobile station shall include NUM_PILOTS_P occurrencesof the following two-field record:

PILOT_PN_PHASE 19

RMS_ERR_PHASE 6

ADD_PILOTS_INCL 1

ADD_BAND_CLASS 0 or 5

ADD_CDMA_FREQ 0 or 11

NUM_ADD_PILOTS_P 0 or 6

If ADD_PILOT_INCL is set to ‘1’, the mobile station shallinclude NUM_ADD_PILOTS_P occurrences of the followingtwo-field record:

ADD_PILOT_PN_PH 19

ADD_RMS_ERR_PH 6


�

TIA/EIA/IS-801

3-39

TIME_REF_MS – The time of validity of the parameters reported in this�


The mobile station shall set this field to�

(t mod 14,400,000), where t is the time of validity in�

units of 1 ms, based on mobile station time reference�

as defined in 6.1.5.1 of TIA/EIA-95-B. This is the time�

at which the values of the parameters reported in this�

response element parameter record are valid.�

OFFSET_INCL – Offset Included.�

If the response element includes MOB_SYS_T_OFFSET��

field, then the mobile station shall set this field to ‘1’;��


MOB_SYS_T_OFFSET – Mobile station system time offset. See 6.1.5.1 of��

TIA/EIA-95-B.��

If the OFFSET_INCL field is set to ‘1’, then the mobile��

station shall set this field to the two’s complement��

value of the offset between mobile station time��

reference and time of occurrence of Reference PN, in��

units of 1/16 TIA/EIA-95-B chips, in the range from��

-512 to +511.9375 TIA/EIA-95-B chips; otherwise the��

mobile station shall not include this field. The sign of��

this quantity shall be positive if the reference PN��

occurs earlier than the mobile station time reference;��


REF_PN – Time reference PN sequence offset.��

The mobile station shall set this field to the PN��

sequence offset of the pilot used by the mobile station��

to derive its time reference, relative to the zero offset��

pilot PN sequence in units of 64 PN chips.��

PILOT_STRENGTH – Pilot strength.��

This parameter conveys the Ec/Io of this pilot (as��

specified in 6.6.6.2.2 of TIA/EIA-95-B), in the units of��

0.5 dB, in the range from 0 to –31.5 dB. The mobile��

station shall set this field to��

-2 × 10 log10 PS,��

TIA/EIA/IS-801

3-40

where PS is the strength of the pilot used by the�

mobile station to derive its time reference (see 6.1.5.1�

of TIA/EIA-95-B), measured as specified in 6.6.6.2.2 of�

TIA/EIA-95-B. If this value (-2 × 10 log10 PS) is less�

than 0, the mobile station shall set this field to�

‘000000’. If this value is greater than 63, the mobile�

station shall set this field to ‘111111’.�

BAND_CLASS – Band class.�

The mobile station shall set this field to the CDMA�

band class of the pilots that are reported in this��

response element, as specified in TSB58-B.��

CDMA_FREQ – Frequency assignment.��

The mobile station shall set this field to the CDMA��

Channel number, in the specified CDMA band class, of��

the pilots that are reported in this response element,��

as specified in 6.1.1.1 of TIA/EIA-95-B.��

BASE_ID – Base Station Identification.��

If the mobile station is on the Paging Channel, the��

mobile station shall set this field to the base station��

identification number obtained from the Paging��

Channel that the mobile station is demodulating;��

otherwise, the mobile station shall set this field to the��

base station identification number obtained from the��

Paging Channel that the mobile station last��

demodulated.��

SID – System Identification.��

If the mobile station is on the Paging Channel, the��

mobile station shall set this field to the system��

identification number obtained from the Paging��

Channel that the mobile station is demodulating;��

otherwise, the mobile station shall set this field to the��

system identification number obtained from the Paging��

Channel that the mobile station last demodulated.��

TIA/EIA/IS-801

3-41

NID – Network Identification.�

If the mobile station is on the Paging Channel, the�

mobile station shall set this field to the network�

identification number obtained from the Paging�

Channel that the mobile station is demodulating;�

otherwise, the mobile station shall set this field to the�

network identification number obtained from the�

Paging Channel that the mobile station last�

demodulated.�

PART_NUM – The part number.��


part number of the Pilot Phase Measurement data, in��

the range from 1 to TOTAL_PARTS.��

TOTAL_PARTS – The total number of parts.��


total number of parts that the Pilot Phase��

Measurement data is divided into, in the range from 1��

to 8.��

NUM_PILOTS_P – Number of pilots in this part.��


pilots to be reported in this part of the response��

element (not including additional pilots, as defined by��

NUM_ADD_PILOTS_P).��

The mobile station shall include NUM_PILOTS_P occurrences of the following pair of fields��

for each pilot in the Active Set, and for each pilot in the Candidate or Neighbor Set whose��

pilot strength is greater than T_DROP15, other than the pilot identified by the REF_PN field.��

PILOT_PN_PHASE – Pilot measured phase.��

The mobile station shall set this field to the phase of��

the pilot PN sequence relative to the zero offset pilot PN��

sequence of this pilot, in units of 1/16 TIA/EIA-95 PN��

chips, in the range from 0 to 32,767.875 chips. The��

pilot arrival time shall be the time of occurrence, as��

measured at the mobile station antenna connector, of��

the earliest arriving usable multipath component of��

the pilot. See 6.6.6.2.4 of TIA/EIA-95-B.��

15 T_DROP is defined in TIA/EIA-95-B.

TIA/EIA/IS-801

3-42

RMS_ERR_PHASE – RMS error in phase measurement. This field�

represents the mobile station’s best estimate of the�

standard deviation of PILOT_PN_PHASE.�

The mobile station shall set this field to a value in the�

range from 1 m to 224 m. A “floating-point”�

representation is used where the 3 most significant�

bits constitute the exponent and the 3 least significant�

bits constitute the mantissa as specified in Table�

3.2.4.2-9.�

��

Table 3.2.4.2-9. RMS Error in Pilot Phase Measurement Representation��


= Y + 8×XFloating-Point

value, fi

RMS Error in PilotPhase Measurement

Value, σ (m)

‘000’ ‘000’ 0 1 σ < 1

‘000’ ‘001’ 1 1.125 1 ≤ σ < 1.125

X Y 2 ≤ i ≤ 61 (1 + Y/8)×2X fi-1 ≤ σ < fi

‘111’ ‘110’ 62 224 208 ≤ σ < 224

‘111’ ‘111’ 63 Not Applicable 224 ≤ σ

��

ADD_PILOTS_INCL – Additional pilots included.��

If this part of the response element includes additional��

pilots belonging to a different CDMA channel number��

or to a different CDMA band class, the mobile station��



ADD_BAND_CLASS – Additional band class.��

If ADD_PILOTS_INCL is set to ‘1’, the mobile station��

shall set this field to the CDMA band class of the��

additional pilots that are reported in this part of the��

response element, as specified in TSB58-B; otherwise��

the mobile station shall not include this field.��

ADD_CDMA_FREQ – Additional frequency assignment.��

If ADD_PILOTS_INCL is set to ‘1’, the mobile station��

shall set this field to the CDMA channel number, in��

the specified CDMA band class, of the additional pilots��

that are reported in the response element, as specified��

in 6.1.1.1 of TIA/EIA-95-B; otherwise the mobile��

station shall not include this field.��

TIA/EIA/IS-801

3-43

NUM_ADD_PILOTS_P – Number of additional pilots in this part.�

If ADD_PILOTS_INCL is set to ‘1’, the mobile station�

shall set this field to the number of additional pilots to�

be reported in this part of the response element;�

otherwise the mobile station shall not include this�

field.�

The mobile station shall include NUM_ADD_PILOTS_P occurrences of the following pair of�

fields for pilots whose pilot strength is greater than T_DROP.�

ADD_PILOT_PN_PH – Additional pilot measured phase.�

The mobile station shall set this field to the phase of��

the pilot PN sequence relative to the zero offset pilot PN��

sequence of this pilot, in units of 1/16 TIA/EIA-95 PN��

chips, in the range from 0 to 32,767.875 chips. The��

pilot arrival time shall be the time of occurrence, as��

measured at the mobile station antenna connector, of��

the earliest arriving usable multipath component of��

the pilot. See 6.6.6.2.4 of TIA/EIA-95-B.��

ADD_RMS_ERR_PH – Additional pilot RMS error in phase measurement.��

This field represents the mobile station’s best estimate��

of the standard deviation of ADD_PILOT_PN_PH.��

The mobile station shall set this field to a value��

according to Table 3.2.4.2-9.��






TIA/EIA/IS-801

3-44

If RESP_TYPE is equal to ‘0001’ (Provide Location Response), RESP_PAR_RECORD shall�

include the following variable length record:�

�

Field Length (bits)

TIME_REF_CDMA 14

LAT 25

LONG 26

LOC_UNCRTNTY_ANG 4

LOC_UNCRTNTY_A 5

LOC_UNCRTNTY_P 5

FIX_TYPE 1

VELOCITY_INCL 1

VELOCITY_HOR 0 or 9

HEADING 0 or 10

VELOCITY_VER 0 or 8

CLOCK_INCL 1

CLOCK_BIAS 0 or 18

CLOCK_DRIFT 0 or 16

HEIGHT_INCL 1

HEIGHT 0 or 14

LOC_UNCRTNTY_V 0 or 5


�


The mobile station shall set this field to (t/50 mod�




of the parameters reported in this response element��

parameter record are valid.��

TIA/EIA/IS-801

3-45

LAT – Latitude.�

The mobile station shall set this field to the two’s�

complement value of the latitude, in units of 180/225

�

degrees, in the range from -90 degrees to +90×(1-2-24

)�

degrees, referenced to the WGS-84 reference ellipsoid,�

counting positive angles north of the equator and�

negative angles south of the equator,�

LONG – Longitude.�


complement value of the longitude, in units of 360/226

��

degrees, in the range from -180 degrees to��

+180×(1-2-25

) degrees, referenced to the WGS-84��

reference ellipsoid, counting positive angles east of the��

Greenwich meridian and negative angles west of the��

Greenwich meridian.��

LOC_UNCRTNTY_ANG– Angle of axis with respect to True North for position��

uncertainty.��

The mobile station shall set this field to the angle of��

axis for position uncertainty, in units of 5.625 degrees,��

in the range from 0 to 84.375 degrees, where 0 degrees��

is True North and the angle increases toward the East.��

LOC_UNCRTNTY_A – Standard deviation of axis along angle specified for��

position uncertainty.��

The mobile station shall set this field to represent the��

standard deviation of axis along angle specified for��

position uncertainty as specified in Table 3.2.4.2-10.��

��

TIA/EIA/IS-801

3-46

Table 3.2.4.2-10. Position Uncertainty�

LOC_UNCRTNTY Standard Deviation for Position Uncertainty (meters)

‘00000’ 0.5

‘00001’ 0.75

‘00010’ 1

‘00011’ 1.5

‘00100’ 2

‘00101’ 3

‘00110’ 4

‘00111’ 6

‘01000’ 8

‘01001’ 12

‘01010’ 16

‘01011’ 24

‘01100’ 32

‘01101’ 48

‘01110’ 64

‘01111’ 96

‘10000’ 128

‘10001’ 192

‘10010’ 256

‘10011’ 384

‘10100’ 512

‘10101’ 768

‘10110’ 1,024

‘10111’ 1,536

‘11000’ 2,048

‘11001’ 3,072

‘11010’ 4,096

‘11011’ 6,144

‘11100’ 8,192

‘11101’ 12,288

‘11110’ >12,288

‘11111’ Not computable

TIA/EIA/IS-801

3-47

�

LOC_UNCRTNTY_P – Standard deviation of axis perpendicular to angle�

specified for position uncertainty.�

The mobile station shall set this field to represent the�

Standard Deviation of Axis Perpendicular to Angle�

Specified for Position Uncertainty as specified in Table�

3.2.4.2-10.�

FIX_TYPE – Fix type.�

The mobile station shall set this field to ‘0’ for 2D fix�

and to ‘1’ for 3D fix.��

VELOCITY_INCL – Velocity information included.��

If velocity information is included in this response��

element, the mobile station shall set this field to ‘1’. If��

velocity information16 is not included in this response��

element, the mobile station shall set this field to ‘0’.��

VELOCITY_HOR – Horizontal velocity magnitude.��

If VELOCITY_INCL is set to ‘1’, the mobile station shall��

set this field to the horizontal velocity, in units of 0.25��

m/s, in the range from 0 to 127.75 m/s; otherwise the��

mobile station shall not include this field.��

Note that this field is not included for cases in which��

the measurement technique does not permit��

calculation of value.��

HEADING – Heading.��

If VELOCITY_INCL is set to ‘1’, the mobile station shall��

set this field to Heading, in units of 360/210 degrees, in��

the range from 0 to 360×(1-2-10) degrees; otherwise the��

mobile station shall not include this field, where 0��

degrees is True North and the angle increases toward��

the East.��




16 Velocity information includes the horizontal and vertical components of velocity, as wellas heading.

TIA/EIA/IS-801

3-48

VELOCITY_VER – Vertical velocity.�

If VELOCITY_INCL and FIX_TYPE are set to ‘1’, the�

mobile station shall set this field to the two’s�

complement value of Vertical Velocity, in units of 0.5�

m/s, in the range from -64 m/s to +63.5 m/s;�

otherwise the mobile station shall not include this�

field.�

Note that this field is not included for cases in which�

the measurement technique does not permit�


CLOCK_INCL – Clock information included.��

If clock information is included in this response��

element, the mobile station shall set this field to ‘1’. If��

clock information is not included in this response��

element, the mobile station shall set this field to ‘0’.��

CLOCK_BIAS – Clock bias.��

If CLOCK_INCL is set to ‘1’, the mobile station shall set��

this field to the clock bias in units of 1 ns, in the range��

from -13,000 ns to +249,143 ns; otherwise the mobile��

station shall not include this field. This parameter is��

computed as true GPS time minus mobile station time��

reference as defined in TIA/EIA-95.��

Note that as part of a GPS fix, the computation yields��

an estimate of the discrepancy between the time��

specified by the local clock and true GPS time. This��

parameter reports the discrepancy. The main cause of��

this discrepancy is going to be the propagation delay��

from the base station to the MS, which is always��

positive. Accordingly, the range allowed for this��

parameter is not symmetric.��

CLOCK_DRIFT – Clock drift.��

If CLOCK_INCL is set to ‘1’, the mobile station shall set��

this field to the two’s complement value of the rate of��

change of clock bias in units of ppb (ns/s), in the��

range from -32768 ppb (ns/s) to +32767 ppb (ns/s);��

otherwise the mobile station shall not include this��

field.��

HEIGHT_INCL – Height information included.��

If height information is included in this response��

element, the mobile station shall set this field to ‘1’;��

otherwise, the mobile station shall set this field to ‘0’.��

TIA/EIA/IS-801

3-49

HEIGHT – Height.�

If HEIGHT_INCL is set to ‘1’, the mobile station shall�

set this field to the height above the WGS-84 reference�

ellipsoid, in units of 1 meter, in the range from -500 m�

to 15833 m; otherwise it shall not include this field.�

LOC_UNCRTNTY_V – Standard deviation of vertical error for position�

uncertainty.�

If HEIGHT_INCL is set to ‘1’, the mobile station shall�

include this field and set this field to represent the�

Standard Deviation Vertical Error for Position��

Uncertainty as specified in Table 3.2.4.2-10; otherwise��

the mobile station shall not include this field.��









If RESP_TYPE is equal to ‘0110’ (Provide Time Offset Measurement), RESP_PAR_RECORD��


��

Field Length (bits)

TIME_REF_MS 24

REF_PN 9

MOB_SYS_T_OFFSET 14

RESERVED 1

��

TIME_REF_MS – The time of validity of the parameters reported in this��

response element.��

The mobile station shall set this field to��

(t mod 14,400,000), where t is the time of validity in��

units of 1 ms, based on mobile station time reference��

as defined in 6.1.5.1 of TIA/EIA-95-B. This is the time��

at which the values of the parameters reported in this��

response element parameter record are valid.��

TIA/EIA/IS-801

3-50

REF_PN – Time reference PN sequence offset.�

The mobile station shall set this field to the PN�

sequence offset of the pilot used by the mobile station�

to derive its time reference, relative to the zero offset�

pilot PN sequence in units of 64 PN chips.�

MOB_SYS_T_OFFSET – Mobile station system time offset.�


complement value of the offset between mobile station�

time reference and time of occurrence of Reference PN,�

in units of 1/16 TIA/EIA-95 chips, in the range from��

-512 to +511.9375 TIA/EIA-95 chips. The sign of this��

quantity shall be positive if the reference PN occurs��

earlier than the mobile station time reference;��




If RESP_TYPE is equal to ‘0111’ (Provide Cancellation Acknowledgement),��


��

Field Length (bits)

CANCEL_TYPE_ACK 4

NO_OUT_REQ 1

RESERVED 3

��

CANCEL_TYPE_ACK – Cancellation type.��


CANCEL_TYPE included in the corresponding request��

element (“Request Cancellation”).��

NO_OUT_REQ – No outstanding request element.��

If there is no outstanding request element of the type��

indicated by CANCEL_TYPE_ACK, the mobile station��





TIA/EIA/IS-801

4-1

4 BASE STATION PROCEDURES�

4.1 Analog Base Station Procedures�

The analog base station procedures are defined in [7].�

4.2 CDMA Base Station Procedures�

4.2.1 Position Determination Data Message Processing�

4.2.1.1 Overview�

The Position Determination Data Message sent by the base station is comprised of request�

elements and response elements, as specified below.�

Request elements sent by base station:�

• Request MS Information��

• Request Autonomous Measurement Weighting Factors��

• Request Pseudorange Measurement��

• Request Pilot Phase Measurement��


• Request Time Offset Measurement��

• Request Cancellation��

Response elements sent by base station:��

• Reject��

• Provide BS Capabilities��

• Provide GPS Acquisition Assistance��

• Provide GPS Location Assistance – Spherical Coordinates��

• Provide GPS Location Assistance – Cartesian Coordinates��

• Provide GPS Sensitivity Assistance��

• Provide Base Station Almanac��

• Provide GPS Almanac��

• Provide GPS Ephemeris��

• Provide GPS Navigation Message Bits��


• Provide GPS Almanac Correction��

The Position Determination Data Message received by the base station is also comprised of��

request elements and response elements, as specified below.��

TIA/EIA/IS-801

4-2

Request elements received by base station:�

• Request BS Capabilities�

• Request GPS Acquisition Assistance�

• Request GPS Location Assistance�

• Request GPS Sensitivity Assistance�

• Request Base Station Almanac�

• Request GPS Almanac�

• Request GPS Ephemeris�

• Request GPS Navigation Message Bits�


• Request GPS Almanac Correction��

Response elements received by base station:��

• Reject��

• Provide MS Information��

• Provide Autonomous Measurement Weighting Factors��

• Provide Pseudorange Measurement��

• Provide Pilot Phase Measurement��


• Provide Time Offset Measurement��

• Provide Cancellation Acknowledgement��

Response elements sent by the base station may be generated in response to request��

elements received by the base station or they may be generated as unsolicited response��

elements. Every request element includes a REQ_TYPE (request element type) field that��

uniquely identifies the request element (See Table 4.2.4-2). Every response element��

includes a RESP_TYPE (response element type) field that uniquely identifies the response��

element (See Table 4.2.4-3). Multiple response elements may be associated with a single��

request element. Unsolicited response elements are sent with the UNSOL_RESP flag set to��

‘1’ (see 4.2.4).��

4.2.1.2 Requirements��

Each Position Determination Data Message shall contain at least one request element, or at��

least one part of a response element, or both. No more than one request element of a��

specific REQ_TYPE shall be included in a Position Determination Data Message. Each��

request element shall be fully contained in a Position Determination Data Message. Some��

response elements may be divided in parts (see 4.2.4.2). Each response element part shall��

be fully contained in a Position Determination Data Message.��

TIA/EIA/IS-801

4-3

If the base station sends a response element in response to a received request element, it�

shall comply with Table 4.2.1.2-1. A “Reject” shall not be sent as a response element to a�

“Request BS Capabilities” request element.�

If one or more response elements from the base station can be useful to the mobile station�

in responding to a request from the base station, the base station should include all or part�

of each response element and the request element in the same Position Determination Data�

Message.�

Upon receiving a Position Determination Data Message, the base station should examine the�

received response elements prior to processing the request elements.�

��

Table 4.2.1.2-1. Response Elements Sent in Response to Received Request Elements��

Request element received Possible response elements

Request BS Capabilities Provide BS Capabilities

RejectRequest GPS Acquisition Assistance

Provide GPS Acquisition Assistance

Reject

Provide GPS Location Assistance –Spherical Coordinates And

Provide GPS Acquisition AssistanceRequest GPS Location Assistance

Provide GPS Location Assistance –Cartesian Coordinates And

Provide GPS Acquisition Assistance

RejectRequest GPS Sensitivity Assistance

Provide GPS Sensitivity Assistance

RejectRequest Base Station Almanac

Provide Base Station Almanac

RejectRequest GPS Almanac

Provide GPS Almanac

RejectRequest GPS Ephemeris

Provide GPS Ephemeris

RejectRequest GPS Navigation Message Bits

Provide GPS Navigation Message Bits

RejectRequest Location Response

Provide Location Response

RejectRequest GPS Almanac Correction

Provide GPS Almanac Correction

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4-4

�

No more than one request element shall be outstanding at any given time for each�

REQ_TYPE. If an additional request element is received while there is an outstanding�

request element of the same type, the additional request element shall be discarded. A�

received (or sent) request element is considered outstanding until all of the corresponding�

response elements or a “Reject” for the request element have been sent (or received).�

Unsolicited response elements shall have the UNSOL_RESP flag set to ‘1’.�

If a “Reject” constitutes the sent response element, its REJ_REQ_TYPE shall be set to the�

REQ_TYPE of the corresponding request element.�

4.2.2 Point-to-point Procedures��

This section defines the procedures for the processing of mobile-terminated Position��

Determination Data Messages that are addressed to individual mobile stations and for the��

processing of all mobile-originated Position Determination Data Messages.��

4.2.2.1 Control Channel Procedure��


A base station supporting Position Determination shall accept and shall process Data Burst��

Messages received on the CDMA Access Channel (see 6.7.1.3.2.3 of TIA/EIA-95-B). The��

processing of TIA/EIA-95-B Layer-2 fields shall be in accordance with TIA/EIA-95-B. Data��

Burst Messages used to transport Position Determination request and response elements��

shall always be acknowledged (Layer 2) and the in-order delivery over the air interface shall��

be guaranteed by the transmitting entities: Mobile station and base station.��

The base station shall process all Data Burst Messages received on the Access Channel and��

having the BURST_TYPE field set to ‘000101’.��

The base station shall discard the message without further processing if one or more of the��

following is true:��




Otherwise, the base station shall process the Position Determination Data contained in the��

CHARi fields of the received Data Burst Message (see 6.7.1.3.2.3 of TIA/EIA-95-B), as��


4.2.2.1.1.1 Mobile Station Request Elements Received��

If the base station does not support the requested capability, the base station shall respond��

with a “Reject” response element with the appropriate reject reason, unless the mobile��

station request element is “Request BS Capabilities”; otherwise, the base station shall��

include the appropriate response elements in the response Position Determination Data��

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(see 4.2.4) as described below. The response Position Determination Data shall reside in�

the CHARi fields of the response Data Burst Message (see 7.7.2.3.2.9 of TIA/EIA-95-B).17�

• Request BS Capability: The base station shall respond with the “Provide BS�

Capabilities” response element.�

• Request GPS Acquisition Assistance: The base station shall respond with the�

“Provide GPS Acquisition Assistance” response element.�

² If DOPP_REQ is set to ‘1’, the “Provide GPS Acquisition Assistance” response�

element shall include the Doppler 0th order term and ADD_DOPP_INCL flag;�

otherwise, the “Provide GPS Acquisition Assistance” response element should�

not include the Doppler 0th order term and ADD_DOPP_INCL flag.��

² If ADD_DOPP_REQ is set to ‘1’, the “Provide GPS Acquisition Assistance”��

response element shall include the high-order Doppler and the Doppler��

search window terms; otherwise, the “Provide GPS Acquisition Assistance”��

response element should not include the high-order Doppler and the Doppler��

search window terms.��

² If CODE_PH_PAR_REQ is set to ‘1’, the “Provide GPS Acquisition Assistance”��

response element shall include the code phase parameters; otherwise, the��

“Provide GPS Acquisition Assistance” response element should not include��

the code phase parameters.��

² If AZ_EL_REQ is set to ‘1’, the “Provide GPS Acquisition Assistance” response��

element shall include the azimuth and elevation angles; otherwise, the��


the azimuth and elevation angles.��

• Request GPS Location Assistance: The base station shall respond with the “Provide��

GPS Location Assistance – Spherical Coordinates” or with the “Provide GPS Location��

Assistance – Cartesian Coordinates” response element. If COORD_TYPE is set to ‘1’,��

the base station shall provide the “Provide GPS Location Assistance – Spherical��

Coordinates” response element; otherwise, the base station shall provide the��

“Provide GPS Location Assistance – Cartesian Coordinates” response element. The��

base station shall also send the “Provide GPS Acquisition Assistance” response��

element in the same Position Determination Data Message that contains the “Provide��

GPS Location Assistance – Spherical Coordinates” response element or the “Provide��

GPS Location Assistance – Cartesian Coordinates” response element. The value of��

NUM_SV_P in each part of the “Provide GPS Location Assistance – Spherical��

Coordinates” response element or the “Provide GPS Location Assistance – Cartesian��

Coordinates” response element shall be the same as the value of NUM_SV_P in the��

part of the “Provide GPS Acquisition Assistance” response element that appears in��

the same Position Determination Data Message. The “Provide GPS Location��

Assistance – Spherical Coordinates” response element or the “Provide GPS Location��

Assistance – Cartesian Coordinates” response element shall have the satellite��


TIA/EIA/IS-801

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related fields repeated in the same SV_PRN_NUM order as contained in the “Provide�

GPS Acquisition Assistance” response element.�

• Request GPS Sensitivity Assistance: The base station shall respond with a “Provide�

GPS Sensitivity Assistance” response element in one or more response Position�

Determination Data Messages, according to the number of parts into which the�

response element is divided.�

• Request Base Station Almanac: The base station shall respond with a “Provide Base�

Station Almanac” response element in one or more response Position Determination�

Data Messages, according to the number of parts into which the response element�

is divided. If EXT_BS_ALM is set to ‘1’, the “Provide Base Station Almanac”��

response element shall include the extended base station almanac; otherwise, the��

“Provide Base Station Almanac” response element shall include the basic base��

station almanac.��

• Request GPS Almanac: The base station shall respond with a “Provide GPS Almanac”��

response element in one or more response Position Determination Data Messages,��

according to the number of parts into which the response element is divided.��

• Request GPS Ephemeris: The base station shall respond with a “Provide GPS��

Ephemeris” response element in one or more response Position Determination Data��

Messages, according to the number of parts into which the response element is��

divided. If AB_PAR_REQ is set to ‘1’, the “Provide GPS Ephemeris” response element��

shall include the Alpha and Beta parameters; otherwise, the “Provide GPS��

Ephemeris” response element should not include the Alpha and Beta parameters.��

• Request GPS Navigation Message Bits: The base station shall respond with a��

“Provide GPS Navigation Message Bits” response element in one or more response��

Position Determination Data Messages, according to the number of parts into which��

the response element is divided. If SUBF_4_5_REQ is set to ‘1’, the “Provide GPS��

Navigation Message Bits” response element shall include the subframes 4 and 5;��

otherwise, the “Provide GPS Navigation Message Bits” response element shall not��

include the subframes 4 and 5.��

• Request Location Response: The base station shall respond with the “Provide��

Location Response“ response element.��

² If HEIGHT_REQ is set to ‘1’, the Location response element should include��

height information; otherwise, the “Provide Location Response” response��

element should not include height information.��


element should include clock correction for mobile station time; otherwise,��

the “Provide Location Response” response element should not include clock��

correction for mobile station time.��




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• Request GPS Almanac Correction: The base station shall respond with a “Provide�

GPS Almanac Correction” response element in one or more response Position�

Determination Data Messages, according to the number of parts into which the�

response element is divided.�

4.2.2.1.1.2 Mobile Station Response Elements Received�

The base station should process and should make use of the mobile station response�

elements. Upon receiving a Position Determination Data Message, the base station should�

examine the received response elements prior to processing the request elements.�



The requirements of this section apply when Position Determination Data Messages��

addressed to individual mobile stations are to be sent by the base station andthe��

destination mobile station is not on a Traffic Channel.��

When the base station has to send one (or more) Position Determination Data Message(s),��

and the addressed mobile station is not on a Traffic Channel, the base station shall��

determine whether the Position Determination Data Message(s) is (are) suitable to be sent on��

the Paging Channel.18 If the Position Determination Data Message(s) is (are) suitable, the��

base station may form one (or more) Paging Channel Data Burst Message(s) (see 7.7.2.3.2.9��

of TIA/EIA-95-B), setting BURST_TYPE to ‘000101’. The base station shall set the��

MSG_NUMBER and NUM_MSGS fields to 1, and shall set the NUM_FIELDS field to the��

number of characters in the Position Determination Data Message(s) (as appropriate).��

When a Position Determination Data Message is to be sent on the Paging Channel, the base��

station shall send the message following the procedures specified in 7.6.2 of TIA/EIA-95-B.��

The base station may send the Position Determination Data Message throughout the area��

where the mobile is registered. Alternatively, the base station may page the mobile station��

to determine which Paging Channel to use to communicate with the mobile; the base��

station may use Service Option 35 or 36 in the Page Record; then, the base station may��

send the Position Determination Data Message on the Paging Channel corresponding to the��

Access Channel on which the mobile station responded. The base station may then send a��

Release Order to the mobile station.��

If the Position Determination Data Message(s) is (are) unsuitable for transmission on the��

Paging Channel19, the base station shall send the Position Determination Data Message(s) on��

the CDMA Traffic Channel, following the procedures defined in 4.2.2.3.��

18The criteria for suitability are implementation dependent.

19For example, the choice to use the Paging Channel or a Forward Traffic Channel, whenmultiple Position Determination Data Messages are waiting to be transmitted, isimplementation dependent.

TIA/EIA/IS-801

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The base station shall set the ACK_REQ Layer-2 field to ‘1’. The base station shall�

guarantee the in-order delivery of Position Determination Data Messages.�

4.2.2.1.2.2 Unsolicited Response Elements�

If “Provide GPS Acquisition Assistance” is sent as an unsolicited response element, the base�

station shall set CODE_PH_PAR_INCL to ‘1’ and it shall include REFERENCE_PN,�

SV_CODE_PH, SV_CODE_PH_INT, GPS_BIT_NUM and SV_CODE_PH_WIN.�

If “Provide GPS Location Assistance – Spherical Coordinates” or the “Provide GPS Location�

Assistance – Cartesian Coordinates” is sent as an unsolicited response element, the base�

station shall also send “Provide GPS Acquisition Assistance” response element in the same�

Position Determination Data Message. The value of NUM_SV_P in each part of the “Provide��

GPS Location Assistance – Spherical Coordinates” response element or the “Provide GPS��

Location Assistance – Cartesian Coordinates” response element shall be the same as the��

value of NUM_SV_P in the part of the “Provide GPS Acquisition Assistance” response��

element that appears in the same Position Determination Data Message. The “Provide GPS��

Location Assistance – Spherical Coordinates” response element or the “Provide GPS��

Location Assistance – Cartesian Coordinates” response element shall have the satellite��

related fields repeated in the same SV_PRN_NUM order as contained in the “Provide GPS��

Acquisition Assistance” response element.��


A “Request Autonomous Measurement Weighting Factors” shall not be issued unless a��

“Request Location Response” is issued in the same Position Determination Data Message.��

4.2.2.2 Authentication Procedures��

If the mobile station includes authentication information when sending an activation��

origination, the base station should process the authentication data as required in 7.3.1 of��

TIA/EIA-95-B. During the position determination session, the base station should invoke��

signaling message encryption whenever available, as appropriate.��

4.2.2.3 Traffic Channel Procedure��

4.2.2.3.1 Message Encryption��

To enhance the security of the position determination session and to protect sensitive��

subscriber location information, the base station should enable message encryption as��

appropriate (see 7.3.2 of TIA/EIA-95-B). Encryption of the Forward and Reverse CDMA��

Traffic Channel messages is defined in Annex A of TIA/EIA-95-B.��

4.2.2.3.2 Negotiation for the Position Determination Service Option��

Negotiation for the Position Determination Service Option is only required when no other��

service option is connected.��

The Position Determination Service Option described by this standard shall use service��

option number 35 and is called Service Option 35 when using Multiplex Option 1. The��

TIA/EIA/IS-801

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Position Determination Service Option shall use service option number 36 and is called�

Service Option 36 when using Multiplex Option 2.�

The base station shall negotiate for Service Option 35 using service negotiation (see�

4.2.2.3.2.1).�

The base station shall negotiate for Service Option 36 using service negotiation (see�

4.2.2.3.2.1).�

4.2.2.3.2.1 Procedures Using Service Negotiation�

The base station shall perform service negotiation for Service Option 35 or Service Option�

36 as described in TIA/EIA-95-B. The negotiated service configuration shall include only�

valid attributes for the negotiated service option consistent with those specified in Tables��

3.2.3.1.2-1 and 3.2.3.1.2-2.��

If the base station establishes a service configuration, as specified in a Service Connect��

Message, that includes a service option connection using Service Option 35 or Service��

Option 36, then the service option connection shall become part of the current service��

configuration at the action time associated with the Service Connect Message. Service��

Option 35 or Service Option 36 is considered to be connected when the current service��

configuration includes a service option connection for it.��

The base station shall not send a Service Option Control Message for Service Option 35 or��

Service Option 36.��


For mobile-originated calls with no dialed digits in the Origination Message, the base station��

should complete an authentication Unique Challenge-Response Procedure (see 6.3.12.1.5��

of TIA/EIA-95-B) immediately after assigning the traffic channel. The Unique Challenge-��

Response Procedure should be completed successfully before Position Determination Data��

Messages are sent to the mobile station and before any mobile-originated Position��

Determination Data Messages are forwarded to other network entities.��

A base station supporting Position Determination shall accept and shall process Data Burst��

Messages received on the CDMA Reverse Traffic Channel (see 6.7.2.3.2.4 of TIA/EIA-95-B).��

Processing of TIA/EIA-95-B Layer-2 fields shall be in accordance with TIA/EIA-95-B. Data��

Burst Messages used to transport Position Determination request and response elements��

shall always be acknowledged (Layer 2) and the in-order delivery over the air interface shall��

be guaranteed by the transmitting entities: Mobile station and base station.��

The base station shall process all Data Burst Messages received on the Reverse Traffic��

Channel and having the BURST_TYPE field set to ‘000101’ (as assigned in TSB58-B). The��

base station shall discard the message without further processing, if one or more of the��

following is true:��




TIA/EIA/IS-801

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Otherwise, the base station shall process the Position Determination Data contained in the�

CHARi fields of the received Data Burst Message (see 6.7.2.3.2.4 of TIA/EIA-95-B), as�

described in the next section.�

If the only connected service option is Service Option 35 or Service Option 36, the base�

station should release the traffic channel when no Position Determination Data Messages�

have been received or have been sent during a period of time which is implementation-�

dependent.�

4.2.2.3.3.1 Mobile Station Request Elements Received�

If the base station does not support the requested capability, the base station shall respond�

with a “Reject” response element with the appropriate reject reason, unless the mobile��

station request element is “Request BS Capabilities”; otherwise, the base station shall��

include the appropriate response elements in the response Position Determination Data��

(see 4.2.4) as described below. The response Position Determination Data shall reside in��

the CHARi fields of the response Data Burst Message (see 7.7.3.3.2.4 of TIA/EIA-95-B).20��

• Request BS Capability: The base station shall respond with the “Provide BS��

Capabilities” response element.��

• Request GPS Acquisition Assistance: The base station shall respond with the��

“Provide GPS Acquisition Assistance” response element.��

² If DOPP_REQ is set to ‘1’, the “Provide GPS Acquisition Assistance” response��

element shall include the Doppler 0th order term and ADD_DOPP_INCL flag;��

otherwise, the “Provide GPS Acquisition Assistance” response element should��

not include the Doppler 0th order term and ADD_DOPP_INCL flag.��

² If ADD_DOPP_REQ is set to ‘1’, the “Provide GPS Acquisition Assistance”��

response element shall include the high-order Doppler and Doppler search��

window terms; otherwise, the “Provide GPS Acquisition Assistance” response��

element should not include the high-order Doppler and Doppler search��

window terms.��

² If CODE_PH_PAR_REQ is set to ‘1’, the “Provide GPS Acquisition Assistance”��

response element shall include the code phase parameters; otherwise, the��


the code phase parameters.��

² If AZ_EL_REQ is set to ‘1’, the “Provide GPS Acquisition Assistance” response��

element shall include the azimuth and elevation angles; otherwise, the��


the azimuth and elevation angles.��

• Request GPS Location Assistance: The base station shall respond with the “Provide��

GPS Location Assistance – Spherical Coordinates” or with the “Provide GPS Location��

Assistance – Cartesian Coordinates” response elements. If COORD_TYPE is set to��


TIA/EIA/IS-801

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‘1’, the base station shall provide the “Provide GPS Location Assistance – Spherical�

Coordinates” response element; otherwise, the base station shall provide the�

“Provide GPS Location Assistance – Cartesian Coordinates” response element. The�

base station shall also send the “Provide GPS Acquisition Assistance” response�

element in the same Position Determination Data Message that contains the “Provide�

GPS Location Assistance – Spherical Coordinates” response element or the “Provide�

GPS Location Assistance – Cartesian Coordinates” response element. The value of�

NUM_SV_P in each part of the “Provide GPS Location Assistance – Spherical�

Coordinates” response element or the “Provide GPS Location Assistance – Cartesian�

Coordinates” response element shall be the same as the value of NUM_SV_P in the��

part of the “Provide GPS Acquisition Assistance” response element that appears in��

the same Position Determination Data Message. The “Provide GPS Location��

Assistance – Spherical Coordinates” response element or the “Provide GPS Location��

Assistance – Cartesian Coordinates” response element shall have the satellite��

related fields repeated in the same SV_PRN_NUM order as contained in the “Provide��

GPS Acquisition Assistance” response element.��

• Request GPS Sensitivity Assistance: The base station shall respond with a “Provide��

GPS Sensitivity Assistance” response element in one or more response Position��

Determination Data Messages, according to the number of parts into which the��

response element is divided.��

• Request Base Station Almanac: The base station shall respond with a “Provide Base��

Station Almanac” response element in one or more response Position Determination��

Data Messages, according to the number of parts into which the response element��

is divided. If EXT_BS_ALM is set to ‘1’, the “Provide Base Station Almanac”��

response element shall include the extended base station almanac; otherwise, the��

“Provide Base Station Almanac” response element shall include the basic base��

station almanac��

• Request GPS Almanac: The base station shall respond with a “Provide GPS Almanac”��

response element in one or more response Position Determination Data Messages,��

according to the number of parts into which the response element is divided.��

• Request GPS Ephemeris: The base station shall respond with a “Provide GPS��

Ephemeris” response element in one or more response Position Determination Data��

Messages, according to the number of parts into which the response element is��

divided. If AB_PAR_REQ is set to ‘1’, the “Provide GPS Ephemeris” response element��

shall include the Alpha and Beta parameters; otherwise, the “Provide GPS��

Ephemeris” response element should not include the Alpha and Beta parameters.��

• Request GPS Navigation Message Bits: The base station shall respond with a��

“Provide GPS Navigation Message Bits” response element in one or more response��

Position Determination Data Messages, according to the number of parts into which��

the response element is divided. If SUBF_4_5_REQ is set to ‘1’, the “Provide GPS��

Navigation Message Bits” response element shall include the subframes 4 and 5;��

otherwise, the “Provide GPS Navigation Message Bits” response element shall not��

include the subframes 4 and 5.��

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• Request Location Response: The base station shall respond with the “Provide�

Location Response” response element.�

² If HEIGHT_REQ is set to ‘1’, the “Provide Location Response” response�

element should include height information; otherwise, the “Provide Location�

Response” response element should not include height information�

² If CLK_COR_GPS_REQ is set to ‘1’, the “Provide Location Response” response�

element should include clock correction for mobile station time; otherwise,�

the “Provide Location Response” response element should not include clock�

correction for mobile station time.�




• Request GPS Almanac Correction: The base station shall respond with a “Provide��

GPS Almanac Correction” response element in one or more response Position��

Determination Data Messages, according to the number of parts into which the��

response element is divided.��

4.2.2.3.3.2 Mobile Station Response Elements Received��

The base station should process and should make use of the mobile station response��

elements. Upon receiving a Position Determination Data Message, the base station should��

examine the received response elements prior to processing the request elements.��

4.2.2.3.4 Traffic Channel Setup��

When a base station is to send Position Determination data on a Traffic Channel, and the��

addressed mobile station is not on a Traffic Channel, the following procedures apply.��

The mobile station address shall be used for messages sent over the paging channel. The��

base station shall page the mobile station and establish a Traffic Channel using the��

procedures defined in 7.6 of TIA/EIA-95-B. The base station shall request Service Option��

35 or Service Option 36.��

When the base station enters the Conversation Substate, the base station may send the��

Position Determination Data Messages in accordance with the procedures defined in��

4.2.2.3.5.��

4.2.2.3.5 Mobile Station Message Termination in the Conversation Substate��


The requirements of this section shall be followed when the addressed mobile station is in��

the TIA/EIA-95-B Conversation Substate of the Mobile Station Control on the Traffic Channel��

State.��

The base station shall form one (or more) Data Burst Message(s) (see 7.7.3.3.2.4 of TIA/EIA-��

95-B), setting BURST_TYPE to ‘000101’ and send the message(s) on the Forward Traffic��

Channel. The base station shall set the MSG_NUMBER and NUM_MSGS fields to 1 and��

TIA/EIA/IS-801

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shall set the NUM_FIELDS field to the number of octets in the Position Determination Data�

message (see 4.2.4). The base station shall set the ACK_REQ Layer-2 field to ‘1’.�

If the only connected service option is Service Option 35 or Service Option 36, the base�

station should release the traffic channel when Position Determination Data Messages have�

not been received or have not been sent during a period of time which is implementation-�

dependent. If any service option in addition to Service Option 35 or Service Option 36 is�

connected, the base station should initiate Service Negotiation to drop Service Option 35 or�

Service Option 36 when Position Determination Data Messages have not been received or�

have not been sent during a period of time which is implementation-dependent. After�

sending a Position Determination Data Message, the base station should delay the traffic��

channel release for a period of time sufficient to allow the mobile station to return any��

requested acknowledgments.��


If “Provide GPS Acquisition Assistance” is sent as an unsolicited response element, the base��

station shall set CODE_PH_PAR_INCL to ‘1’ and it shall include REFERENCE_PN,��

SV_CODE_PH, SV_CODE_PH_INT, GPS_BIT_NUM and SV_CODE_PH_WIN.��

If “Provide GPS Location Assistance – Spherical Coordinates” or the “Provide GPS Location��

Assistance – Cartesian Coordinates” is sent as an unsolicited response element, the base��

station shall also send “Provide GPS Acquisition Assistance” response element in the same��

Position Determination Data Message. The value of NUM_SV_P in each part of the “Provide��

GPS Location Assistance – Spherical Coordinates” response element or the “Provide GPS��

Location Assistance – Cartesian Coordinates” response element shall be the same as the��

value of NUM_SV_P in the part of the “Provide GPS Acquisition Assistance” response��

element that appears in the same Position Determination Data Message. The “Provide GPS��

Location Assistance – Spherical Coordinates” response element or the “Provide GPS��

Location Assistance – Cartesian Coordinates” response element shall have the satellite��

related fields repeated in the same SV_PRN_NUM order as contained in the “Provide GPS��

Acquisition Assistance” response element.��


A “Request Autonomous Measurement Weighting Factors” shall not be issued unless a��

“Request Location Response” is issued in the same Position Determination Data Message.��

4.2.3 Broadcast Procedures��

Reserved��

4.2.4 Forward Link Message Format��

The forward link Position Determination Data Messages are summarized in Table 4.2.4-1.��

��

TIA/EIA/IS-801

4-14

Table 4.2.4-1. Forward Link Messages�

Message Name PD_MSG_TYPE

Position Determination DataMessage

‘00000000’

Reserved for future standardization ‘00000001’ through‘10111111’

Available for manufacturer-specificPosition Determination DataMessage definition as specified inTSB-58

‘11000000’ through‘11111110’

Reserved ‘11111111’

�

The Position Determination Data Message from base station to mobile station has the�

following variable length message format:�

�

Field Length (bits)

SESS_START 1

SESS_END 1

SESS_SOURCE 1

SESS_TAG 5

PD_MSG_TYPE (‘00000000’) 8

NUM_REQUESTS 4

NUM_RESPONSES 4

The base station shall include NUM_REQUESTS occurrencesof the following record:

RESERVED 4

REQ_TYPE 4

REQ_PAR_LEN 8

REQ_PAR_RECORD 8×REQ_PAR_LEN

The base station shall include NUM_RESPONSESoccurrences of the following record:

RESERVED 3

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UNSOL_RESP 1

RESP_TYPE 4

RESP_PAR_LEN 8

RESP_PAR_RECORD 8 × RESP_PAR_LEN

�

SESS_START – Start-of-session indicator.�

If the base station has previously sent or received a�

Position Determination Data Message related to this�

Position Determination Data Message (as defined in�

2.2.1) it shall set this field to ‘0’; otherwise, it shall set�


SESS_END – End-of-session indicator.�

If the base station does not expect to receive or send�

any more Position Determination Data Messages related��

to this Position Determination Data Message (as defined��

in 2.2.1) the base station shall set this field to ‘1’;��

otherwise, it shall set this field to ‘0’. The criteria for��

setting this field are implementation dependent.��

SESS_SOURCE – Session-source indicator.21��

If SESS_START is set to ‘1’ the base station shall set��

this field to ‘0’; otherwise it shall set this field to the��

same value as the SESS_SOURCE field that appeared��

in a previously-received or previously-sent Position��

Determination Data Message that was related to this��

Position Determination Data Message (as defined in��

2.2.1).��

21 This field indicates which side (mobile station or base station) initiated this session.

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SESS_TAG – Session tag.�

If SESS_START is set to ‘0’ the base station shall set�

this field to the same value as the SESS_TAG field that�

appeared in a previously-received or previously-sent�

Position Determination Data Message that was related�

to this Position Determination Data Message (as defined�

in 2.2.1); otherwise, the base station shall set this field�

to one more (modulo 32) than the value it assigned to�

this field in the latest Position Determination Data�

Message that it sent with SESS_START set to ‘1’. If no��

such latest Position Determination Data Message��

exists, the base station shall set this field to ‘00000’.��

The definition of “latest” is implementation dependent.��

PD_MSG_TYPE – Position Determination Data Message type.��

The base station shall set this field to ‘00000000’.��

NUM_REQUESTS – Number of request element parameter records.��

The base station shall set this field to the number of��

request element parameters record included in the��

message.��

NUM_RESPONSES – Number of response element parameter records.��


response element parameters record included in the��

message.��



REQ_TYPE – Request element type.��

The base station shall set this field to the value shown��

in Table 4.2.4-2.��

��

TIA/EIA/IS-801

4-17

Table 4.2.4-2. Request Element Type�

DescriptionREQ_TYPE

(binary)

Reserved ‘0000’

Request MS Information ‘0010’

Request Autonomous Measurement Weighting Factors ‘0011’

Request Pseudorange Measurement ‘0100’

Request Pilot Phase Measurement ‘0101’

Request Location Response ‘0001’

Request Time Offset Measurement ‘0110’

Request Cancellation ‘0111’

All other REQ_TYPE values are reserved.

�

REQ_PAR_LEN – Request element parameters length.�

The base station shall set this field to the number of�

octets included in the REQ_PAR_RECORD field.�

REQ_PAR_RECORD – Request element parameters record.�

The base station shall set this record as described in�

4.2.4.1.�


The base station shall set these bits to ‘000’.��

UNSOL_RESP – Unsolicited response indicator.��

The base station shall set this field to ‘1’ if the��

response element is an unsolicited response element;��

otherwise the base station shall set this field to ‘0’.��

RESP_TYPE – Response element type.��

The base station shall set this field to the value shown��

in Table 4.2.4-3.��

TIA/EIA/IS-801

4-18

�

Table 4.2.4-3. Response Element Type�

DescriptionRESP_TYPE

(binary)

Reject ‘0000’

Provide BS Capabilities ‘0010’

Provide GPS Acquisition Assistance ‘0100’

Provide GPS Location Assistance – Spherical Coordinates ‘0110’

Provide GPS Location Assistance – Cartesian Coordinates ‘0111’

Provide GPS Sensitivity Assistance ‘0101’

Provide Base Station Almanac ‘0011’

Provide GPS Almanac ‘1000’

Provide GPS Ephemeris ‘1001’

Provide GPS Navigation Message Bits ‘1010’

Provide Location Response ‘0001’

Provide GPS Almanac Correction ‘1011’

All other RESP_TYPE values are reserved.

�

RESP_PAR_LEN – Response element parameters length.�

The base station shall set RESP_PAR_LEN to the�

number of octets included in the RESP_PAR_RECORD�

field.�

RESP_PAR_RECORD – Response element parameters record.�

The base station shall set this record as described in�

4.2.4.2.��

4.2.4.1 Request Element Parameters Record��

If REQ_TYPE in Position Determination Data Message is equal to ‘0010’, or if REQ_TYPE is��

equal to ‘0011’, the base station shall not include this record. If REQ_TYPE is equal to��

‘0001’, or if REQ_TYPE is equal to ‘0100’, or if REQ_TYPE is equal to ‘0101’, or if REQ_TYPE��

is equal to ‘0110’, or if REQ_TYPE is equal to ‘0111’, the base station shall include the��

record REQ_PAR_RECORD and set its fields as described below.��

If REQ_TYPE in Position Determination Data Message is equal to ‘0100’ (Request��

Pseudorange Measurement), REQ_PAR_RECORD shall include the following fields:��

��

TIA/EIA/IS-801

4-19

Field Length (bits)

PREF_RESP_QUAL 3

NUM_FIXES 8

T_BETW_FIXES 8

OFFSET_REQ 1

RESERVED 4

�

PREF_RESP_QUAL – Preferred response quality.�

The base station shall set this according to 3.2.2.1.1.1�

and 3.2.2.3.3.1.�

NUM_FIXES – Number of fixes.�

The base station shall set this field to the requested�

number of fixes, in the range from 1 to 255.�

T_BETW_FIXES – Time between fixes.�


seconds between fixes, in the range from 0 to 255.��

OFFSET_REQ – Offset requested.��

If REF_PN and MOB_SYS_T_OFFSET are requested,��

the base station shall set this field to ‘1’; otherwise the��

base station shall set this field to ‘0’.��



If REQ_TYPE is equal to ‘0101’ (Request Pilot Phase Measurement), REQ_PAR_RECORD��

shall include the following fields:��

��

Field Length (bits)

PREF_RESP_QUAL 3

NUM_FIXES 8

T_BETW_FIXES 8

OFFSET_REQ 1

DESI_PIL_PH_RES 1

RESERVED 3

��

PREF_RESP_QUAL – Preferred response quality.��

TIA/EIA/IS-801

4-20

The base station shall set this field according to�

3.2.2.1.1.1 and 3.2.2.3.3.1.�






seconds between fixes, in the range from 0 to 255.�

OFFSET_REQ – Offset requested.�

If MOB_SYS_T_OFFSET is requested, the base station��

shall set this field to ‘1’; otherwise the base station��


DESI_PIL_PH_RES – Desired pilot phase resolution.��

If at least one TIA/EIA-95 PN chip pilot phase��

resolution is requested, the base station shall set this��

field to ‘0’. If at least 1/8 TIA/EIA-95 PN chip pilot��

phase resolution is requested, the base station shall��

set this field to ‘1’.��



If REQ_TYPE is equal to ‘0001’ (Request Location Response), REQ_PAR_RECORD shall��

include the following fields:��

��

Field Length (bits)

PREF_RESP_QUAL 3

NUM_FIXES 8

T_BETW_FIXES 8

HEIGHT_REQ 1

CLK_COR_GPS_REQ 1

VELOCITY_REQ 1

RESERVED 2

��

PREF_RESP_QUAL – Preferred response quality.��

The base station shall set this field according to��

3.2.2.1.1.1 and 3.2.2.3.3.1.��

TIA/EIA/IS-801

4-21






seconds between fixes, in the range from 0 to 255.�

HEIGHT_REQ – Height information requested.�

If the height information is requested, the base station�

shall set this field to ‘1’; otherwise the base station�


CLK_COR_GPS_REQ – Clock correction for GPS time requested.��

If the clock correction for GPS time is requested, the��

base station shall set this field to ‘1’; otherwise the��


VELOCITY_REQ – Velocity information requested.��

If velocity information is requested, the base station��

shall set this field to ‘1’; otherwise the base station��




If REQ_TYPE is equal to ‘0110’ (Request Time Offset Measurement), REQ_PAR_RECORD��

shall include the following fields:��

��

Field Length (bits)

USE_TIME 1

ACTION_TIME 0 or 6

RESERVED 7 or 1 (as needed)

��

USE_TIME – Use action time indicator.��

This field indicates whether an ACTION_TIME is��

specified in this request element.��

If an ACTION_TIME is specified in this message, the��

base station shall set this field to ‘1’; otherwise, the��


ACTION_TIME – Action time.��

TIA/EIA/IS-801

4-22

If the USE_TIME field is set to ‘1’, the base station�

shall set this field to the System Time, in units of 80�

ms (modulo 64), at which the offset measurement is to�

take effect. If the USE_TIME field is set to ‘0’ the base�

station shall not include this field.�


The base station shall add reserved bits as needed in�

order to make the length of the request element�


octets. The base station shall set these bits to ‘0’.��

If REQ_TYPE is equal to ‘0111’ (Request Cancellation), REQ_PAR_RECORD shall include��

the following fields:��

��

Field Length (bits)

CANCEL_TYPE 4

RESERVED 4

��

CANCEL_TYPE – Cancellation type.��

The base station shall set this field to the type of��

request element to be cancelled, according to Table��

4.4.1.1-1.��



4.2.4.2 Response Element Parameters Record��

The base station shall set RESP_PAR_RECORD as described below.��

If RESP_TYPE in Position Determination Data Message is equal to ‘0000’ (Reject),��


��

Field Length (bits)

REJ_REQ_TYPE 4

REJ_REASON 3

RESERVED 1

��

REJ_REQ_TYPE – Reject request type.��

TIA/EIA/IS-801

4-23

The base station shall set this field to the value of the�

REQ_TYPE corresponding to the request element it�

rejects. See 3.2.4.�

REJ_REASON – Reject reason.�

The base station shall set this field to the value shown�

in Table 4.2.4.2-1.�

�

Table 4.2.4.2-1. Reject Reason�

Reason for rejectionREJ_REASON

(binary)

Capability not supported by the base station ‘000’

Capability normally supported by the base station buttemporarily not available or not enabled

‘001’

All other REJ_REASON values are reserved.

�



If RESP_TYPE is equal to ‘0010’ (Provide BS Capabilities), RESP_PAR_RECORD shall��

include the following fields:��

��

Field Length (bits)

BS_LS_REV 6

GPSC_ID 1

AFLTC_ID 1

APDC_ID 8

��

BS_LS_REV – The base station location standard revision number.��


GPSC_ID – GPS capability indicator.��

If the base station can do all of the following:��

• provide the “GPS Assist” response elements��

(“Provide GPS Acquisition Assistance”; “Provide��

GPS Location Assistance – Spherical Coordinates”;��

“Provide GPS Location Assistance – Cartesian��

Coordinates”; “Provide GPS Sensitivity Assistance”;��

TIA/EIA/IS-801

4-24

“Provide GPS Almanac”; “Provide GPS Ephemeris”;�

“Provide GPS Navigation Message Bits”), and�

• determine the position of the mobile station based�

on information provided by the mobile station�

through the GPS response elements (“Provide�

Autonomous Measurement Weighting Factors”;�

“Provide Pseudorange Measurement”), and�

• accept a “Provide Location Response” response�

element from the mobile station with autonomous�

positioning technology,��

then the base station shall set this field to ‘1’;��


AFLTC_ID – Advanced forward link trilateration capability��

indicator.��


• provide the “Provide Base Station Almanac”��

response element, and��

• determine the position of the mobile station based��

on information provided by the mobile station��

through the “Provide Pilot Phase Measurement”��

response element, and��

• accept a “Provide Location Response” response��

element from the mobile station with autonomous��


then the base station shall set this field to ‘1’;��


APDC_ID – Autonomous position determination capability��

indicator.��


• determine the position of the mobile station��

autonomously (i.e., without mobile station��

involvement), and��

• accept a “Provide Location Response” response��

element from the mobile station with autonomous��


then the base station shall set this field to a value��

other than ‘00000000’ according to Table 4.2.4.2-2;��

otherwise the base station shall set this field to��

‘00000000’.��

TIA/EIA/IS-801

4-25

�

Table 4.2.4.2-2. Autonomous Location Determination Capability in the Base Station�

APDC_ID Location Determination Capability

‘00000000’No Autonomous Location DeterminationCapability

‘00000001’ – ‘11111111’ Autonomous Location Technology Identifier

�

If RESP_TYPE is equal to ‘0100’ (Provide GPS Acquisition Assistance), RESP_PAR_RECORD�

shall include the following record:�

�

Field Length (bits)

NUM_SV 4

TIME_OF_APP 8

DOPP_INCL 1

ADD_DOPP_INCL 0 or 1

CODE_PH_PAR_INCL 1

REFERENCE_PN 0 or 10

AZ_EL_INCL 1

The base station shall include NUM_SV occurrences of thefollowing fields:

SV_PRN_NUM 6

DOPPLER0 0 or 12

DOPPLER1 0 or 7

DOPPLER_WIN 0 or 3

SV_CODE_PH 0 or 10

SV_CODE_PH_INT 0 or 5

GPS_BIT_NUM 0 or 2

SV_CODE_PH_WIN 0 or 5

AZIMUTH 0 or 5

ELEVATION 0 or 3


�

NUM_SV – Number of GPS satellites.�

TIA/EIA/IS-801

4-26


repeated data fields for all applicable satellites, in the�


conveys the number of satellites minus one.�

TIME_OF_APP – The CDMA system time reference for the GPS�

Acquisition Assist information.�

The base station shall set this field to the CDMA�

system time reference, in units of 1.28 s, in the range�

from 0 to 318.72 s.�

DOPP_INCL – Doppler (0th order) term included.��

If DOPPLER0 is included in this response element, the��

base station shall set this field to ‘1’; otherwise the��


ADD_DOPP_INCL – Additional Doppler information included.��

If DOPP_INCL is set to ‘1’, the base station shall��

include this field and, if DOPPLER1 and��

DOPPLER_WIN are included in this response element,��

it shall set ADD_DOPP_INCL to ‘1’; if DOPPLER1 and��

DOPPLER_WIN are not included in this response��

element, it shall set ADD_DOPP_INCL to ‘0’. If��

DOPP_INCL is set to ‘0’, the base station shall not��

include this field.��

CODE_PH_PAR_INCL – Code phase information included.��

If code phase information is included in this response��

element, the base station shall set this field to ‘1’. If��

code phase information is not included in this��

response element, the base station shall set this field��

to ‘0’.��

REFERENCE_PN – Reference PN.��

If CODE_PH_PAR_INCL is set to ‘1’, the base station��

shall include this field and set the most significant bit��

of this field to ‘0’ and the 9 least significant bits of this��

field to the PN sequence offset of the pilot used as time��

reference by the base station for the SV_CODE_PH��

information included in this element, relative to the��

zero offset pilot PN sequence in units of 64 PN chips.��

If the SV_CODE_PH information included in this��

element does not use any pilot PN sequence as its��

reference, then the base station shall set this field to��

‘1000000000’. See Table 4.2.4.2-3. If��

CODE_PH_PAR_INCL is set to ‘0’, the base station��


TIA/EIA/IS-801

4-27

�

Table 4.2.4.2-3. Reference PN�

REFERENCE_PN

(binary)

PN sequence offset value

‘0xxxxxxxxx’ ‘xxxxxxxxx’

‘1000000000’ No Pilot PN sequence used as reference

All other REFERENCE_PN values are reserved.

�

AZ_EL_INCL – Azimuth and elevation angle included.�

If azimuth and elevation angle are included in this�

response element, the base station shall set this field�

to ‘1’. If azimuth and elevation angle are not included�

in this response element, the base station shall set�


SV_PRN_NUM – The satellite PRN number.��






DOPPLER0 – The 0th order Doppler.��

If DOPP_INCL is set to ‘1’, the base station shall set��

this field to the two’s complement value of the 0th order��

Doppler, in units of 2.5 Hz, in the range from -5120 Hz��

to +5117.5 Hz; otherwise the base station shall not��

include this field.��

Note: Generally, this value is obtained from a��

specification of the associated parameter that has a��

larger number of bits of resolution. These values shall��

be obtained by simple truncation without round-off.��

DOPPLER1 – The 1st order Doppler.��

If ADD_DOPP_INCL is included and set to ‘1’, the base��

station shall set this field to the two’s complement��

value of the 1st order Doppler, in units of 1/64 Hz/s, in��

the range from -1 Hz/s to +63/64 Hz/s; otherwise the��

base station shall not include this field.��

DOPPLER_WIN – The Doppler search window.��

TIA/EIA/IS-801

4-28

If ADD_DOPP_INCL is included and ADD_DOPP_INCL�

is set to ‘1’, the base station shall set this field to�

represent the Doppler search window as specified in�

Table 4.2.4.2-4; otherwise the base station shall not�

include this field.�

�

Table 4.2.4.2-4. DOPPLER_WIN Parameter Format�

DOPPLER_WIN Doppler Search Window

‘000’ 200 Hz

‘001’ 100 Hz

‘010’ 50 Hz

‘011’ 25 Hz

‘100’ 12.5 Hz

All other values of DOPPLER_WIN are reserved.

�

SV_CODE_PH – The GPS code phase.�

If CODE_PH_PAR_ INCL is set to ‘1’, the base station��

shall include this field and set this field to the code��

phase in GPS chip, in the range from 0 to 1022 GPS��

chips; otherwise, the base station shall not include��

this field.��

SV_CODE_PH_INT – The integer number of code periods that have elapsed��

since the latest GPS bit boundary.��


shall set this field to number of the code periods that��

have elapsed since the latest GPS bit boundary, in��

units of C/A code period, in the range from 0 to 19;��

otherwise the base station shall not include this field.��

GPS_BIT_NUM – The two least significant bits of the bit number (within��

the GPS frame) being currently transmitted.��


shall set this field to represent the two least significant��

bits of the bit number being received at TIME_OF_APP��

in the range from 0 to 3; otherwise the base station��


SV_CODE_PH_WIN – The total code phase window.��


shall set this field to represent the two sided code��

TIA/EIA/IS-801

4-29

phase search window as specified in Table 4.2.4.2-5;�

otherwise the base station shall not include this field.�

�

Table 4.2.4.2-5. Code Phase Search Window Parameter Format�

SV_CODE_PH_WIN Code Phase Search Window

(GPS chips)

‘00000’ 1023

‘00001’ 1

00010’ 2

‘00011’ 3

‘00100’ 4

‘00101’ 5

‘00110’ 6

‘00111’ 8

‘01000’ 10

‘01001’ 12

‘01010’ 14

‘01011’ 18

‘01100’ 22

‘01101’ 26

‘01110’ 30

‘01111’ 38

‘10000’ 46

‘10001’ 54

‘10010’ 62

‘10011’ 78

‘10100’ 94

‘10101’ 110

‘10110’ 126

TIA/EIA/IS-801

4-30

‘10111’ 158

‘11000’ 190

‘11001’ 222

‘11010’ 254

‘11011’ 318

‘11100’ 382

‘11101’ 446

‘11110’ 512

‘11111’ 640

�

AZIMUTH – Azimuth of the GPS satellite.�

If AZ_EL_ INCL is set to ‘1’, the base station shall set�

this field to the azimuth, in units of 11.25 degrees, in�

the range from 0 to 348.75 degrees; otherwise the base�

station shall not include this field.�

Note: Generally, this value is obtained from a�

specification of the associated parameter that has a�

larger number of bits of resolution. These values shall�


ELEVATION – Elevation angle of the GPS satellite.��

If AZ_EL_ INCL is set to ‘1’, the base station shall set��

this field to the elevation angle, in units of 11.25��

degrees, in the range from 0 to 78.75 degrees;��


Note: Generally, this value is obtained from a��

specification of the associated parameter that has a��

larger number of bits of resolution. These values shall��



The base station shall add reserved bits as needed in��




��

TIA/EIA/IS-801

4-31

If RESP_TYPE is equal to ‘0110’ (Provide GPS Location Assistance – Spherical Coordinates),�

RESP_PAR_RECORD shall include the following record:�

�

Field Length (bits)

LAT_REF 20

LONG_REF 20

HEIGHT_REF 7

NUM_DLY 3

NUM_SV 4

The base station shall include NUM_DLY occurrences of thefollowing fields:

PILOT_PN 9

DLY_ONEWAY 11


DOPPLER0_LSB 4

SV_CODE_PH_FR 10

AZIMUTH_LSB 11

ELEVATION_LSB 11


�

LAT_REF – Reference latitude.�

The base station shall set this field to the two’s�

complement value of the latitude, in units of 180/220

�


)�

degrees, referenced to the WGS-84 reference ellipsoid,�

counting positive angles north of the equator and��

negative angles south of the equator.��

LONG_REF – Reference longitude.��

The base station shall set this field to the two’s��

complement value of the longitude, in units of 360/220

��

degrees, in the range from -180 degrees to��

+180×(1-2-19

) degrees, referenced to the WGS-84��

reference ellipsoid, counting positive angles east of the��

Greenwich meridian and negative angles west of the��

Greenwich meridian.��

TIA/EIA/IS-801

4-32

HEIGHT_REF – Reference height.�

The base station shall set this field to the reference�

height, in units of 40 m, in the range from -400 m to�

+4680 m.�

Note that the reference height is defined as the height�

above the WGS-84 reference ellipsoid.�

NUM_DLY – Number of delays.�


repeated data fields for all applicable PN offsets, in the�

range from 0 to 7.��

NUM_SV – Number of GPS satellites.��


repeated data fields for all applicable satellites, in the��


conveys the number of satellites minus one .��

PILOT_PN – Pilot PN sequence offset index.��

The base station shall set this field to the pilot PN��

sequence offset for the base station, in units of 64��

TIA/EIA-95 PN chips.��

DLY_ONEWAY – One way delay.��

The base station shall set this field to the one way��

delay, in units of 1/16 TIA/EIA-95 PN chips, in the��

range from 0 to 127.9375 chips.��

DOPPLER0_LSB – The LSB’s of the 0th order term Doppler. This field is a��

resolution extension of DOPPLER0 in a “Provide GPS��

Acquisition Assistance” response element. When��

appended to the bit representation DOPPLER0 in a��

“Provide GPS Acquisition Assistance” response element��

included in the same Position Determination Data��

Message, it provides higher-resolution version of the��

0th order term Doppler.��

The base station shall set this field to the LSB’s of the��

0th order Doppler, in units of 2.5/24 Hz, in the range��

from 0 to 2.5×(1-2-4) Hz.��

SV_CODE_PH_FR – The fractional chip of code phase. This field is a��

resolution extension of SV_CODE_PH in “Provide GPS��


appended to the chip representation SV_CODE_PH in��

“Provide GPS Acquisition Assistance” response��

TIA/EIA/IS-801

4-33

element, it provides higher-resolution version of the�

code phase.�

The base station shall set this field to the fractional�

chip of code phase, in units of 2-10 GPS chips, in the�

range from 0 to (1- 2-10) chips.�

AZIMUTH_LSB – The LSB’s of the azimuth. This field is a resolution�

extension of AZIMUTH in a “Provide GPS Acquisition�

Assistance” response element. When appended to the�

bit representation AZIMUTH in a “Provide GPS�

Acquisition Assistance” response element included in��

the same Position Determination Data Message, it��

provides higher-resolution version of the azimuth.��


azimuth, in units of 11.25/211 degrees, in the range��

from 0 to 11.25×(1-2-11) degrees.��

ELEVATION_LSB – The LSB’s of the elevation angle. This field is a��

resolution extension of ELEVATION in a “Provide GPS��


appended to the bit representation ELEVATION in a��

“Provide GPS Acquisition Assistance” response element��

included in the same Position Determination Data��

Message, it provides higher-resolution version of the��

elevation angle.��


elevation angle, in units of 11.25/211 degrees, in the��

range from 0 to 11.25×(1-2-11) degrees.��






If RESP_TYPE is equal to ‘0111’ (Provide GPS Location Assistance – Cartesian Coordinates),��


��

Field Length (bits)

NUM_DLY 3

NUM_SV 4

The base station shall include NUM_DLY occurrences of thefollowing fields:

TIA/EIA/IS-801

4-34

PILOT_PN 9

DLY_ONEWAY 11


DOPPLER0_LSB 4

SV_COOR_X 27

SV_COOR_Y 27

SV_COOR_Z 27


�

NUM_DLY – Number of delays.�


repeated data fields for all applicable PN offsets, in the�

range from 0 to 7.�

NUM_SV – Number of GPS satellites.�


repeated data fields for all applicable satellites, in the�


conveys the number of satellites minus one.��



sequence offset for the base station, in units of 64��

TIA/EIA-95 PN chips.��

DLY_ONEWAY – One way delay.��

The base station shall set this field to the One way��

delay, in units of 1/16 TIA/EIA-95 PN chips, in the��

range from 0 to 127.9375 chips.��

DOPPLER0_LSB – This field is a resolution extension of DOPPLER0 in a��

“Provide GPS Acquisition Assistance” response��

element. When appended to the bit representation��

DOPPLER0 in a “Provide GPS Acquisition Assistance”��

response element included in the same Position��

Determination Data Message, it provides higher-��

resolution version of the 0th order term Doppler.��


0th order Doppler, in units of 2.5/24 Hz, in the range��

from 0 to 2.5×(1-2-4) Hz.��

TIA/EIA/IS-801

4-35

SV_COOR_X – The X coordinate of the satellite in ECEF format.�


complement of the X coordinate of the satellite, in�

units of 0.4125 m, in the range from -0.4125×226 m to�

0.4125×(226 - 1) m.�

SV_COOR_Y – The Y coordinate of the satellite in ECEF format.�


complement of the Y coordinate of the satellite, in�

units of 0.4125 m, in the range from -0.4125×226 m to�

0.4125×(226 - 1) m.��

SV_COOR_Z – The Z coordinate of the satellite in ECEF format.��


complement of the Z coordinate of the satellite, in��

units of 0.4125 m, in the range from -0.4125×226 m to��

0.4125×(226 - 1) m.��






TIA/EIA/IS-801

4-36

If RESP_TYPE is equal to ‘0101’ (Provide GPS Sensitivity Assistance), RESP_PAR_RECORD�

shall include the following record:�

�

Field Length (bits)

REF_BIT_NUM 11

NUM_DR_P 4

DR_SIZE 8

PART_NUM 3

TOTAL_PARTS 3

The base station shall include NUM_DR_P occurrences of thefollowing record of (NUM_SV_DR+2) fields:

NAV_MSG_BITS 2 × DR_SIZE

NUM_SV_DR 4

The base station shall include NUM_SV_DR occurrences ofthe following field:

SV_PRN_NUM 6


�

REF_BIT_NUM – The reference bit number.�

This parameter conveys the position of a particular bit�

in the 1500-bit GPS frame to be called the “reference�

bit”, which is the last bit of the first half of the�

NAV_MSG_BITS field. The base station shall set this�

field to the position of the reference bit in the range��

from 0 to 1499.��

NUM_DR_P – Number of data records in this part.��

The base station shall set this field to specify the��

number of repeated records in this part of the��

response element, in the range from 0 to 15.��

DR_SIZE – Data record size.��

The base station shall set this field to specify the data��

record size in 2-bit units, in the range from 0 to 510��

bits.��

TIA/EIA/IS-801

4-37


The base station shall set this field to specify the part�

number of the GPS Sensitivity Assistance data, in the�

range from 1 to TOTAL_PARTS.�

TOTAL_PARTS – The total number of parts.�

The base station shall set this field to specify the total�

number of parts that the GPS Sensitivity Assistance�

data is divided into, in the range from 1 to 8.�

NAV_MSG_BITS – Navigation message bits.�


Navigation message bits.��

NUM_SV_DR – Number of GPS satellites in this data record.��


repeated data fields for all applicable satellites in this��

data record, in the range from 1 to 16, where the��

binary value of the field conveys the number of��

satellites minus one.��












If RESP_TYPE is equal to ‘0011’ (Provide Base Station Almanac), RESP_PAR_RECORD shall��

include the following record:��

��

TIA/EIA/IS-801

4-38

Field Length (bits)

REF_PN 9

TIME_CRRCTION_REF 9

LAT_REF 23

LONG_REF 24

HEIGHT_REF 10

PART_NUM 3

TOTAL_PARTS 3

NUM_PILOTS_P 9

The base station shall include NUM_PILOTS_P occurrences ofthe following six-field record:

PILOT_PN 9

TIME_CORRECTION 9

LOC_SAME_AS_PREV 1

DELTA_LAT 0 or 16

DELTA_LONG 0 or 16

HEIGHT 0 or 10


�

REF_PN – Pilot PN sequence offset of the reference base station.�

The base station shall set this field to the pilot PN�

sequence offset of the pilot transmitted by the�

reference base station with respect to which locations�

of other base stations are reported, relative to the zero�

offset pilot PN sequence in units of 64 PN chips.�

TIME_CRRCTION_REF– Reference time correction.�


complement value of the reference time correction of��

the base station transmitting pilot REF_PN in units of��

1/16 TIA/EIA-95 PN chips, in the range from -16 to��

+15.9375 chips.��

TIA/EIA/IS-801

4-39

LAT_REF – Reference latitude.�

The base station shall set this field to the latitude of the�

base station antenna transmitting pilot REF_PN,�

referenced to the WGS-84 reference ellipsoid, in units�

of 0.125” (arc seconds), expressed as a two’s complement�

signed number with positive numbers signifying north�

latitudes. The base station shall set this field to a value�

in the range from –324000” to 324000” inclusive�

(corresponding to the range from -90° to +90°).�

LONG_REF – Reference longitude.��

The base station shall set this field to the longitude of the��

base station antenna transmitting pilot REF_PN,��

referenced to the WGS-84 reference ellipsoid, in units��

of 0.125” (arc seconds), expressed as a two’s complement��

signed number with positive numbers signifying east��

longitudes. The base station shall set this field to a value��

in the range from –648000” to 648000” inclusive��

(corresponding to the range from -180° to +180°).��

HEIGHT_REF – Reference height.��

The base station shall set this field to the height, above��

the WGS-84 reference ellipsoid, of the base station��

antenna transmitting pilot REF_PN, in units of 4 m, in��

the range from 0 to 4092 m.��


The base station shall set this field to specify the part��

number of the Base Station Almanac data, in the��

range from 1 to TOTAL_PARTS.��


The base station shall set this field to specify the total��

number of parts that the Base Station Almanac data is��

divided into, in the range from 1 to 8.��

NUM_PILOTS_P – Number of pilots in this part.��


pilots to be reported in this part of the response��

element, in the range from 0 to 511.��



sequence offset of the pilot transmitted by the base��

station whose location is being reported, relative to the��

zero offset pilot PN sequence in units of 64 PN chips.��

TIA/EIA/IS-801

4-40

TIME_ CORRECTION – The (GPS) reference time correction for Pilot PILOT_PN.�


complement value of the reference time correction of�

the base station antenna transmitting pilot PILOT_PN,�

in units of 1/16 TIA/EIA-95 PN chips, expressed as a�

two’s complement signed number in the range from�

-16 to +15.9375 chips.�

LOC_SAME_AS_PREV– Location same as the previous.�

If the location of the base station antenna transmitting�

this pilot PN is the same as the location of the previous��

base station antenna, the base station shall set this��

field to ‘1’; otherwise, the base station shall set this��

field to ‘0’.��

DELTA_LAT – The difference in the latitude of this base station��

antenna and the latitude of the reference base station��

antenna.��

If LOC_SAME_AS_PREV is set to ‘0’, the base station shall��

set this field to the difference in the latitude of the base��

station antenna transmitting pilot PILOT_PN and the��

latitude of the reference base station antenna (latitude��

of base station antenna transmitting pilot PILOT_PN��

minus latitude of reference base station antenna) with��

both latitudes referenced to the WGS-84 reference��

ellipsoid, in units of 0.125 s, expressed as a two’s��

complement signed number in the range from -1024 s��

to +1023.875 s; otherwise, the base station shall omit��

this field.��

DELTA_LONG – The difference in the longitude of this base station��

antenna and the longitude of the primary base station��

antenna.��

If LOC_SAME_AS_PREV is set to ‘0’, the base station shall��

set this field to the difference in the longitude of the��

base station antenna transmitting PILOT_PN and the��

longitude of the reference base station antenna��

(longitude of base station antenna transmitting pilot��

PILOT_PN minus longitude of reference base station��

antenna) with both longitudes referenced to the��

WGS-84 reference ellipsoid, in units of 0.125 s,��

expressed as a two’s complement signed number in the��

range from -1024 s to +1023.875 s; otherwise, the base��

station shall omit this field.��

TIA/EIA/IS-801

4-41

HEIGHT – The height of the base station antenna.�

The base station shall set this field to the height, above�

the WGS-84 reference ellipsoid, of the base station�

antenna transmitting pilot PILOT_PN, in units of 4 m,�

in the range form 0 to 4092 m.�






If RESP_TYPE is equal to ‘1000’ (Provide GPS Almanac), RESP_PAR_RECORD shall include��

the following record:��

��

Field Length (bits)

NUM_SV_P 6

WEEK_NUM 8

TOA 8

PART_NUM 5

TOTAL_PARTS 5

The base station shall include NUM_SV_P occurrences of thefollowing ten-field record:

SV_PRN_NUM 5

DELTA_INCLINATION 16

MO 24

ECCENTRICITY 16

A_SQRT 24

OMEGA_0 24

OMEGA 24

OMEGADOT 16

AF1 11

AF0 11


��

TIA/EIA/IS-801

4-42

NUM_SV_P – Number of satellites in this part.�

The base station shall set this field to specify the�

number of repeated records for all applicable satellites�

in this part of response element, in the range from 1 to�

64, where the binary value of the field conveys the�

number of satellites minus one.�

WEEK_NUM – The GPS week number of the almanac.�

The base station shall set this field to the 8 least�

significant bits of the GPS week number of the�

almanac22 from which parameters in this message are��

obtained. The range for this field is from 0 to 255.��

TOA – The reference time of the almanac.��


reference time of the almanac22 from which parameters��

in this message are obtained, in units of 4096 s, in the��

range from 0 to 602,112 s.��


The base station shall set this field to specify the part��

number of the Almanac data, in the range from 1 to��

TOTAL_PARTS.��



number of parts that the Almanac data is divided into,��

in the range from 1 to 32.��







DELTA_INCLINATION – Correction to inclination.��

The base station shall set this field to the value��

contained in the associated parameter of the specified��

GPS almanac22

.��

22 This parameter is as defined in ICD200(http://www.navcen.uscg.mil/gps/geninfo/gpsdocuments/icd200/default.htm).

TIA/EIA/IS-801

4-43

M0 – Mean anomaly at reference time.�

The base station shall set this field to the value�

contained in the associated parameter of the specified�

GPS almanac22

.�

ECCENTRICITY – Eccentricity.�



GPS almanac22

.�

A_SQRT – Square root of the semi-major axis.�



GPS almanac22

.��

OMEGA_0 – Longitude of ascending node of orbit plane at weekly��

epoch.��



GPS almanac22

.��

OMEGA – Argument of perigee.��



GPS almanac22

.��

OMEGADOT – Rate of right ascension.��



GPS almanac22

.��

AF1 – Apparent satellite clock correction af1.��



GPS almanac22

.��




GPS almanac22

.��






TIA/EIA/IS-801

4-44

If RESP_TYPE is equal to ‘1001’ (Provide GPS Ephemeris), RESP_PAR_RECORD shall�


�

Field Length (bits)

NUM_SV_P 4

PART_NUM 5

TOTAL_PARTS 5

AB_PAR_INCL 1

ALPHA_0 0 or 8

ALPHA_1 0 or 8

ALPHA_2 0 or 8

ALPHA_3 0 or 8

BETA_0 0 or 8

BETA _1 0 or 8

BETA _2 0 or 8

BETA _3 0 or 8

The base station shall include NUM_SV_P occurrences of thefollowing twenty-two-field record:

SV_PRN_NUM 5

IODE 8

C_RS 16

DELTA_N 16

M0 32

C_UC 16

ECCENTRICITY 32

C_US 16

A_SQRT 32

TOE 16

C_IC 16

OMEGA_0 32

C_IS 16

ANGLE_INCLINATION 32

C_RC 16

OMEGA 32

OMEGADOT 24

TIA/EIA/IS-801

4-45

IDOT 14

TOC 16

AF2 8

AF1 16

AF0 22


�


The base station shall set this field to specify the�

number of repeated records for all applicable satellites�

in this part of the response element, in the range from�

1 to 16, where the binary value of the field conveys the�

number of satellites minus one.�



number of the Ephemeris data, in the range from 1 to��

TOTAL_PARTS.��



number of parts that the Ephemeris data is divided��

into, in the range from 1 to 32.��

AB_PAR_INCL – Inclusion of the alpha and beta parameters.��

The base station shall set this field to ‘1’ if the alpha��

and beta parameters are included in the response��

element; otherwise the base station shall set this field��

to ‘0’.��

ALPHA_0 – Ionospheric correction parameter α0.��

If AB_PAR_INCL is set to ‘1’, the base station shall set��

this field to the value contained in the associated��

parameter of the specified GPS ephemeris23; otherwise��

the base station shall not include this field.��

23 This parameter is as defined in ICD200(http://www.navcen.uscg.mil/gps/geninfo/gpsdocuments/icd200/default.htm).

TIA/EIA/IS-801

4-46

ALPHA_1 – Ionospheric correction parameter α1.�

If AB_PAR_INCL is set to ‘1’, the base station shall set�

this field to the value contained in the associated�

parameter of the specified GPS ephemeris23; otherwise�

the base station shall not include this field.�

ALPHA_2 – Ionospheric correction parameter α2.�

If AB_PAR_INCL is set to ‘1’, the base station shall set�

this field to the value contained in the associated�

parameter of the specified GPS ephemeris23; otherwise�


ALPHA_3 – Ionospheric correction parameter α3.��





BETA_0 – Ionospheric correction parameter β0.��
























TIA/EIA/IS-801

4-47



IODE – Issue of data.�



GPS ephemeris23.�

C_RS – Amplitude of the sine harmonic correction term to the�

orbit radius.�



GPS ephemeris23.��

DELTA_N – Mean motion difference from the computed value.��




M0 – Mean anomaly at the reference time.��




C_UC – Amplitude of the cosine harmonic correction term to��

the argument of latitude.��




ECCENTRICITY – Eccentricity.��




C_US – Amplitude of the sine harmonic correction term to the��

argument of latitude.��




A_SQRT – Square root of the semi-major axis.��




TIA/EIA/IS-801

4-48

TOE – ephemeris reference time.�



GPS ephemeris23.�

C_IC – Amplitude of the cosine harmonic correction term to�

the angle of inclination.�



GPS ephemeris23.�

OMEGA_0 – Longitude of ascending node of orbit plane at weekly��

epoch.��




C_IS – Amplitude of the sine harmonic correction term to the��

angle of inclination.��




ANGLE_INCLINATION– Inclination angle at the reference time.��




C_RC – Amplitude of the cosine harmonic correction term to��

the orbit radius.��




OMEGA – Argument of perigee.��




OMEGADOT – Rate of right ascension.��




TIA/EIA/IS-801

4-49

IDOT – Rate of inclination angle.�



GPS ephemeris23.�

TOC – Clock data reference time.�



GPS ephemeris23.�

AF2 – Apparent satellite clock correction af2.�

















If RESP_TYPE is equal to ‘1010’ (Provide GPS Navigation Message Bits),��


��

Field Length (bits)

NUM_SV_P 6

PART_NUM 5

TOTAL_PARTS 5

SUBF_4_5_INCL 1

SUBF_4_5 0 or 15000

The base station shall include NUM_SV_P occurrences of thefollowing two-field record:

TIA/EIA/IS-801

4-50

SV_PRN_NUM 6

SUB_1_2_3 900


�



repeated records for all applicable satellites in this part�

of the response element, in the range from 1 to 64,�

where the binary value of the field conveys the number�

of satellites minus one.�



number of the GPS Navigation Message Bits data, in��

the range from 1 to TOTAL_PARTS.��



number of parts that the GPS Navigation Message Bits��

data is divided into, in the range from 1 to 32.��

SUBF_4_5_INCL – Inclusion of the additional parameters indicator.��

The base station shall set this field to ‘1’ if the��

subframes 4 and 5 are included in the response��

element; otherwise the base station shall set this field��

to ‘0’.��

SUBF_4_5 – GPS subframes 4 and 5.��

If SUBF_4_5_INCL is set to ‘1’, the base station shall��

set this field to the contents of GPS navigation��

message subframes 4 and 5; otherwise the base��

station shall not include this field.��

Note that the data shall be current as of the time of��

transmission; time-dependent fields shall be��

represented as they will occur in the next whole frame��

(for subframes 1, 2 and 3) or in the next whole��

superframe (for subframes 4 and 5) from the time the��

request is received by the base station.��




TIA/EIA/IS-801

4-51




SUBF_1_2_3 – The subframes 1, 2 and 3.�

The base station shall set this field to the contents of�

GPS navigation message subframes 1, 2 and 3�

transmitted by the satellite specified in the previous�

field.�

Note that the data shall be current as of the time of�

transmission; time-dependent fields shall be��

represented as they will occur in the next whole frame��

(for subframes 1, 2 and 3) or in the next whole��

superframe (for subframes 4 and 5) from the time the��

request is received by the base station.��






If RESP_TYPE is equal to ‘0001’ (Provide Location Response), RESP_PAR_RECORD shall��

include the following record:��

��

TIA/EIA/IS-801

4-52

Field Length (bits)

TIME_REF_CDMA 14

LAT 25

LONG 26

LOC_UNCRTNTY_ANG 4

LOC_UNCRTNTY_A 5

LOC_UNCRTNTY_P 5

FIX_TYPE 1

VELOCITY_INCL 1

VELOCITY_HOR 0 or 9

HEADING 0 or 10

VELOCITY_VER 0 or 8

CLOCK_INCL 1

CLOCK_BIAS 0 or 18

CLOCK_DRIFT 0 or 16

HEIGHT_INCL 1

HEIGHT 0 or 14

LOC_UNCRTNTY_V 0 or 5


�


The base station shall set this field to (t/50 mod�




of the parameters reported in this response element�

parameter record are valid.�

LAT – Latitude.�


complement value of the latitude, referenced to the��

WGS-84 reference ellipsoid, in units of 180/225

��


)��

degrees, counting positive angles north of the equator��

and negative angles south of the equator.��

TIA/EIA/IS-801

4-53

LONG – Longitude.�


complement value of the longitude, referenced to the�

WGS-84 reference ellipsoid, in units of 360/226

�

degrees, in the range from -180 degrees to�

+180×(1-2-25

) degrees, counting positive angles east of�

the Greenwich meridian and negative angles west of�

the Greenwich meridian.�

LOC_UNCRTNTY_ANG– Angle of axis with respect to True North for position�

uncertainty.��

The base station shall set this field to the angle of axis��

for position uncertainty, in units of 5.625 degrees, in��

the range from 0 to 84.375 degrees, where 0 degrees is��

True North and the angle increases toward the East.��

LOC_UNCRTNTY_A – Standard deviation of axis along angle specified for��

position uncertainty.��

The base station shall set this field to represent the��

standard deviation of axis along angle specified for��

position uncertainty as specified in Table 4.2.4.2-6.��

��

TIA/EIA/IS-801

4-54

Table 4.2.4.2-6. Position Uncertainty�

LOC_UNCRTNTY Standard Deviation forPosition Uncertainty(meters)

‘00000’ 0.5

‘00001’ 0.75

‘00010’ 1

‘00011’ 1.5

‘00100’ 2

‘00101’ 3

‘00110’ 4

‘00111’ 6

‘01000’ 8

‘01001’ 12

‘01010’ 16

‘01011’ 24

‘01100’ 32

‘01101’ 48

‘01110’ 64

‘01111’ 96

‘10000’ 128

‘10001’ 192

‘10010’ 256

‘10011’ 384

‘10100’ 512

‘10101’ 768

‘10110’ 1,024

‘10111’ 1,536

‘11000’ 2,048

‘11001’ 3,072

‘11010’ 4,096

‘11011’ 6,144

TIA/EIA/IS-801

4-55

‘11100’ 8,192

‘11101’ 12,288

‘11110’ >12,288

‘11111’ Not computable

LOC_UNCRTNTY_P – Standard deviation of axis perpendicular to angle�

specified for position uncertainty.�

The base station shall set this field to represent the�

Standard Deviation of Axis Perpendicular to Angle�

Specified for Position Uncertainty as specified in Table�

4.2.4.2-6.�

FIX_TYPE – Fix type.�

The base station shall set this field to ‘0’ for 2D fix and�

to ‘1’ for 3D fix.�

VELOCITY_INCL – Velocity information included.��

If velocity information is included in this response��


velocity information is not included in this response��

element, the base station shall set this field to ‘0’.��

VELOCITY_HOR – Horizontal velocity magnitude.��

If VELOCITY_INCL is set to ‘1’, the base station shall��

set this field to the horizontal velocity, in units of 0.25��

m/s, in the range from 0 to 127.75 m/s; otherwise the��

base station shall not include this field.��




HEADING – Heading.��

If VELOCITY_INCL is set to ‘1’, the base station shall��

set this field to Heading, in units of 360/210 degrees, in��

the range from 0 to 360×(1-2-10) degrees; otherwise the��

base station shall not include this field, where 0��

degrees is True North and the angle increases toward��

the East.��




TIA/EIA/IS-801

4-56

VELOCITY_VER – Vertical velocity.�

If VELOCITY_INCL and FIX_TYPE are set to ‘1’, the�

base station shall set this field to the two’s�

complement value of Vertical Velocity, in units of 0.5�

m/s, in the range from -64 m/s to +63.5 m/s;�

otherwise the base station shall not include this field.�

Note that this field is not included for cases in which�

the measurement technique does not permit�

calculation of value.�

CLOCK_INCL – Clock information included.��

If clock information is included in this response��


clock information is not included in this response��

element, the base station shall set this field to ‘0’.��

CLOCK_BIAS – Clock bias.��

If CLOCK_INCL is set to ‘1’, the base station shall set��

this field to the clock bias in ns, in the range from��

-13,000 ns to +249,143 ns; otherwise the base station��

shall not include this field. This parameter is��

computed as true GPS time minus mobile station time��

reference as defined in TIA/EIA-95.��

Note that as part of a GPS fix, the computation yields��

an estimate of the discrepancy between the time��

specified by the local clock and true GPS time. This��

parameter reports the discrepancy. The main cause of��

this discrepancy is going to be the propagation delay��

from the base station to the MS, which is always��

positive. Accordingly, the range allowed for this��

parameter is not symmetric.��

CLOCK_DRIFT – Clock drift.��

If CLOCK_INCL is set to ‘1’, the base station shall set��

this field to the two’s complement value of the rate of��

change of clock bias in units of ppb (ns/s), in the��

range from -32768 ppb (ns/s) to +32767 ppb (ns/s);��


HEIGHT_INCL – Height information included.��

If height information is included in this response��


HEIGHT is not included in this response element, the��


TIA/EIA/IS-801

4-57

HEIGHT – Height.�

If HEIGHT_INCL is set to ‘1’, the base station shall set�

this field to the height, above WGS-84 reference�

ellipsoid, in units of 1 meter, in the range from -500 m�

to 15833 m; otherwise it shall not include this field.�

LOC_UNCRTNTY_V – Standard deviation of vertical error for position�

uncertainty.�

If HEIGHT_INCL is set to ‘1’, the base station shall�

include this field and set this field to represent the�

Standard Deviation Vertical Error for Position��

Uncertainty as specified in Table 4.2.4.2-6; otherwise��










If RESP_TYPE is equal to ‘1011’ (Provide GPS Almanac Correction), RESP_PAR_RECORD��


��

Field Length (bits)

NUM_SV_P 4

REF_TIME 8

TOA 8

WEEK_NUM 8

PART_NUM 5

TOT_PARTS 5

The base station shall include NUM_SV_P occurrences of thefollowing fields:

SV_PRN_NUM 5

DELTA_XYZ_INCL 1

DELTA_X 0 or 15

DELTA_Y 0 or 15

DELTA_Z 0 or 15

DELTA_X_1ST 0 or 7

TIA/EIA/IS-801

4-58

DELTA_Y_1ST 0 or 7

DELTA_Z_1ST 0 or 7

DELTA_CLOCK_INCL 1

DELTA_CLOCK 0 or 17

DELTA_CLOCK_1ST 0 or 8


�

NUM_SV_P – Number of satellites in the part.�


satellites in this part of the response element, in the�


conveys the number of satellites minus one.�

REF_TIME – The time of validity of the parameters reported in this�


The base station shall set this field to the time of�

validity of these almanac corrections.��

The base station shall set this field to (t/1280 mod��

250), where t is the GPS time of validity of the��

corrections in units of 1 ms.��

TOA – Time of almanac.��


reference time of the almanac from which parameters��

in this message are obtained, in units of 4096 s, in the��

range from 0 to 602,112 s.��

WEEK_NUM – GPS week number.��

The base station shall set this field to the 8 least��

significant bits of the GPS week number of the��

almanac for which the almanac corrections are��

provided. The range for this field is from 0 to 255.��

PART_NUM – Part number.��


the current part in the response element, in the range��

from 1 to 32.��

TIA/EIA/IS-801

4-59

TOT_PARTS – Total parts.�

The base station shall set this field to the total number�

of parts that constitute the response element, in the�

range from 1 to 32.�

SV_PRN_NUM – The satellite PRN number.�

The mobile station shall set this field to the value of�

the PRN signal number for which the measured data is�




DELTA_XYZ_INCL – Correction for XYZ included.��

The base station shall set this field to ‘1’ if delta XYZ��

information is included in the message; otherwise it��

shall set this field to ‘0’.24��

DELTA_X – Correction for X coordinate.��

If DELTA_XYZ_INCL is set to ‘1’ the base station shall��

include DELTA_X and set this field to the two’s��

complement value of the 0th order position correction X��

term, in units of 0.5 m, in the range from -8192 m to��

+8191.5 m; otherwise the base station shall not��

include this field24.��

DELTA_Y – Correction for Y coordinate.��


include DELTA_Y and set this field to the two’s��

complement value of the 0th order position correction Y��




DELTA_Z – Correction for Z coordinate.��


include DELTA_Z and set this field to the two’s��

complement value of the 0th order position correction Z��




24 See 3.2.2.1.1.2 and 3.2.2.3.3.2

TIA/EIA/IS-801

4-60

DELTA_X_1ST – 1st order correction for X coordinate.�

If DELTA_XYZ_INCL is set to ‘1’ the base station shall�

include DELTA_X_1ST and set this field to the two’s�

complement value of the 1st order position correction X�

term, in units of 2.5 cm/s, in the range from -160�

cm/s to +157.5 cm/s; otherwise the base station shall�

not include this field.�

DELTA_Y_1ST – 1st order correction for Y coordinate.�

If DELTA_XYZ_INCL is set to ‘1’ the base station shall�

include DELTA_Y_1ST and set this field to the two’s��

complement value of the 1st order position correction Y��

term, in units of 2.5 cm/s, in the range from -160��

cm/s to +157.5 cm/s; otherwise the base station shall��

not include this field.��

DELTA_Z_1ST – 1st order correction for Z coordinate.��


include DELTA_Z_1ST and set this field to the two’s��

complement value of the 1st order position correction Z��

term, in units of 2.5 cm/s, in the range from -160��

cm/s to +157.5 cm/s; otherwise the base station shall��

not include this field.��

DELTA_CLOCK_INCL – Correction for clock included.��

The base station shall set this field to ‘1’ if delta clock��

information is included in the message; otherwise it��


DELTA_CLOCK – Correction for clock.��

If DELTA_CLOCK_INCL is set to ‘1’ the base station��

shall include DELTA_CLOCK and set this field to the��

two’s complement value of the delta clock 0th order, in��

units of 1 ns, in the range from -65536 ns to��

65535 ns; otherwise the base station shall not include��

this field.��

DELTA_CLOCK_1ST – 1st order correction for clock.��

If DELTA_CLOCK_INCL is set to ‘1’ the base station��

shall include DELTA_CLOCK_1ST and set this field to��

the two’s complement value of the delta clock 1st order,��

in units of 0.1 ppb, in the range from -12.8 ppb to��

+12.7 ppb; otherwise the base station shall not include��

this field.��

TIA/EIA/IS-801

4-61





octets. The base station shall set these bits to ‘0’.�

TIA/EIA/IS-801

4-62

No text.�

TIA/EIA/IS-801

A-1

Annex A - TIMERS�

The following table provides values for time limits given in the text.�

Table A-1. Time Limits�

TimeLimit

Description Value References

T1 Time limit for preferred quality of “Provide PseudorangeMeasurement”, “Provide Pilot Phase Measurement” and“Provide Location Response” response elements whenPREF_RESP_QUAL = ‘000’

2 s 3.2.2.1.1.1

3.2.2.3.3.1


4 s 3.2.2.1.1.1

3.2.2.3.3.1


8 s 3.2.2.1.1.1

3.2.2.3.3.1


16 s 3.2.2.1.1.1

3.2.2.3.3.1


32 s 3.2.2.1.1.1

3.2.2.3.3.1


64 s 3.2.2.1.1.1

3.2.2.3.3.1


128 s 3.2.2.1.1.1

3.2.2.3.3.1


256 s 3.2.2.1.1.1

3.2.2.3.3.1

T9 The time limit for the mobile station to wait for a responseor a “Reject” to a sent request element

35 s 3.2.1.2

�

TIA/EIA/IS-801

A-2

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TIA/EIA/IS-801

B-1

Annex B – REQUEST/RESPONSE ELEMENT TYPES�

Table B-1. MS Requests and BS Responses�

Code REQUEST Elements sent by MS Code RESPONSE Elements sent by BS

0000 Reserved 0000 Reject

0001 Request Location Response 0001 Provide Location Response

0010 Request BS Capabilities 0010 Provide BS Capabilities

0011 Request Base Station Almanac 0011 Provide Base Station Almanac

0100 Request GPS Acquisition Assistance 0100 Provide GPS Acquisition Assistance

0101 Request GPS Sensitivity Assistance 0101 Provide GPS Sensitivity Assistance

0110 Request GPS Location Assistance 0110 Provide GPS Location Assistance –Spherical Coordinate

0111 Reserved 0111 Provide GPS Location Assistance –Cartesian Coordinate

1000 Request GPS Almanac 1000 Provide GPS Almanac

1001 Request GPS Ephemeris 1001 Provide GPS Ephemeris

1010 Request GPS Navigation Message Bits 1010 Provide GPS Navigation Message Bits

1011 Request GPS Almanac Correction 1011 Provide GPS Almanac Correction

See Table 3.2.4-2. Request Element Type and Table 4.2.4-3. Response Element Type.�

�

Table B-2. MS Responses and BS Requests�

Code RESPONSE Elements sent by MS Code REQUEST Elements sent by BS

0000 Reject 0000 Reserved

0001 Provide Location Response 0001 Request Location Response

0010 Provide MS Information 0010 Request MS Information

0011 Provide Autonomous MeasurementWeighting Factor

0011 Request Autonomous MeasurementWeighting Factor

0100 Provide Pseudorange Measurement 0100 Request Pseudorange Measurement

0101 Provide Pilot Phase Measurement 0101 Request Pilot Phase Measurement

0110 Provide Time Offset Measurement 0110 Request Time Offset Measurement

0111 Provide Cancellation Acknowledgement 0111 Request Cancellation

See Table 3.2.4-3. Response Element Type and Table 4.2.4-2. Request Element Type.�

TIA/EIA/IS-801

B-2

No text.�

TIA/EIA/IS-801

C-1

Annex C – EXAMPLE POSITION DETERMINATION DATA MESSAGE�

The following is an example of a mobile station originated Position Determination Data�

Message. The example merely serves as an aid in understanding the format specified in the�

body of the document. The example accommodates two mobile station requests, along with�

a mobile station response (to a previous base station request to the mobile). The example�

shows how the individual records (and fields) (i.e. REQ_TYPEs, REQ_PAR_RECORDs, etc.)�

are built from the most significant bit (MSB) to the least significant bit (LSB), the length of�

the individual records, and the ordering of the individual records within the final Position�

Determination Data Message. Finally, the entire bit string for the Position Determination�

Data Message is constructed.��

The Mobile requests the following information from the base station:��

• GPS Acquisition Assistance��

• GPS Almanac Correction��

The mobile is also responding to a base station request for “Provide MS Information”��

response element.��

Individual fields of the Position Determination Data Message are listed in Table C-1. The��

message begins with the PD_MSG_TYPE record and ends with a RESERVED record.��

��

Table C-1. Bit Field of the Position Determination Data Message��

FIELD TYPE MSB → LSB COMMENTS

SESS_START 0 Not the first message of a session

SESS_END 1 The last message of a session

SESS_SOURCE 0 Base station originated the session

SESS_TAG 01100 Tag of the session

PD_MSG_TYPE 00000000 From Table 3.2.4-1

NUM_REQUESTS 0010 Making 2 requests

NUM_RESPONSES 0001 Making 1 response

REQ_TYPE 00000100 Request GPS Acquisition Assistance

REQ_PAR_LEN 00000001 indicates one octet in followingREQ_PAR_RECORD

REQ_PAR_RECORD 11110000 Requests DOPP_REQ, ADD_DOPP_REQ,CODE_PH_PAR_REQ, AZ_EL_REQ + 4RESERVED bits

REQ_TYPE 00001011 Request GPS Almanac Correction

REQ_PAR_LEN 00000010 Two octets in following REQ_PAR_RECORD

TIA/EIA/IS-801

C-2

REQ_PAR_RECORD

TOA 10010011 Requested reference Time Of Almanac =602112 s

WEEK_NUM 10101010 Requested WEEK_NUM = 170

UNSOL_RESP 0000 Reserved bits + including a response to anearlier BSS request with the above requests

RESP_TYPE 0100 Provide MS Information

RESP_PAR_LEN 00000110 six octets in following REQ_PAR_RECORD

RESP_PAR_RECORD

MS_LS_LEV 000000 by definition

MS_MODE 0000 by definition

PILOT_PH_CAP 000000 set to indicate Full Chip MeasurementCapability (Table 3.2.4.2-2)

GPS_ACQ_CAP 000000100001 set to indicate GPS Acquisition Assistanceand GPS Almanac Correction Capability(Table 3.2.4.2-3)

LOC_CALC_CAP 000010100101 set to indicate Location Assistance-Spherical, AFLT, GPS Almanac Correction,Hybrid Position Calculation Capability(Table 3.2.4.2-4)

�

Therefore the entire Position Determination Data Message consists of 16 octets or 128 bits�

as follows:�

MSB and beginning of message�

↓�

00000000001000010000010000000001111100000000�

10110000001001011001001110101010000001000000�

0110000000000000000000100001000010100101�

↑�

LSB end of message��

��

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