Home > Documents > CDMA overview

CDMA overview

Date post: 21-Dec-2015
Category:
Author: vivek-khandelwal
View: 220 times
Download: 4 times
Share this document with a friend
Description:
gives all required info regarding 1X call flow and using codes
Embed Size (px)
Popular Tags:
of 144 /144
February, 2000 7 - 1 RF100 (c) 1998 Scott Baxt er Technical Introduction to CDMA Course RF100 Chapter 7
Transcript
  • Technical Introduction to CDMACourse RF100 Chapter 7

    RF100 (c) 1998 Scott Baxter

  • Course OutlineBasic CDMA PrinciplesCodingForward and Reverse ChannelsCDMA Operational DetailsMultiplexing, Forward and Reverse Power ControlCDMA Handset ArchitectureCDMA HandoffsCDMA Network ArchitectureCDMA Messaging and Call FlowOptional TopicsWireless Multiple Access TechnologiesOverview of Current TechnologiesCapacity; CDMA Overlays, Spectrum Clearing

    RF100 (c) 1998 Scott Baxter

  • Section AHow Does CDMA Work?Introduction to Basic Principles

    RF100 (c) 1998 Scott Baxter

  • CDMA: Using A New DimensionAll CDMA users occupy the same frequency at the same time! Frequency and time are not used as discriminatorsCDMA operates by using CODING to discriminate between usersCDMA interference comes mainly from nearby usersEach user is a small voice in a roaring crowd -- but with a uniquely recoverable codeFigure of Merit: C/I(carrier/interference ratio)AMPS: +17 dBTDMA: +14 to +17 dBGSM: +7 to 9 dB.CDMA: -10 to -17 dB.CDMA: Eb/No ~+6 dB.

    RF100 (c) 1998 Scott Baxter

  • Two Types of CDMAThere are Two types of CDMA:Frequency-HoppingEach users narrowband signal hops among discrete frequencies, and the receiver follows in sequenceFrequency-Hopping Spread Spectrum (FHSS) CDMA is NOT currently used in wireless systems, although used by the militaryDirect Sequencenarrowband input from a user is coded (spread) by a user-unique broadband code, then transmittedbroadband signal is received; receiver knows, applies users code, recovers users dataDirect Sequence Spread Spectrum (DSSS) CDMA IS the method used in IS-95 commercial systems

    RF100 (c) 1998 Scott Baxter

  • DSSS Spreading: Time-Domain ViewAt Originating Site:Input A: Users Data @ 19,200 bits/secondInput B: Walsh Code #23 @ 1.2288 McpsOutput: Spread spectrum signalAt Destination Site:Input A: Received spread spectrum signalInput B: Walsh Code #23 @ 1.2288 McpsOutput: Users Data @ 19,200 bits/second just as originally sentDrawn to actual scale and time alignmentvia air interface Originating SiteDestination Site

    RF100 (c) 1998 Scott Baxter

  • Spreading from a Frequency-Domain ViewTraditional technologies try to squeeze signal into minimum required bandwidthCDMA uses larger bandwidth but uses resulting processing gain to increase capacity

    RF100 (c) 1998 Scott Baxter

  • CDMA Uses Code ChannelsA CDMA signal uses many chips to convey just one bit of information Each user has a unique chip pattern, in effect a code channelTo recover a bit, integrate a large number of chips interpreted by the users known code patternOther users code patterns appear random and integrate in a random self-canceling fashion, dont disturb the bit decoding decision being made with the proper code pattern

    RF100 (c) 1998 Scott Baxter

  • CDMA: The Code Magic behind the VeilThis figure illustrates the basic technique of CDMA signal generation and recovery.The actual coding process used in IS-95 CDMA includes a few additional layers, as well see in following slides.

    RF100 (c) 1998 Scott Baxter

  • Spreading: What we do, we can undoSender combines data with a fast spreading sequence, transmits spread data streamReceiver intercepts the stream, uses same spreading sequence to extract original data

    RF100 (c) 1998 Scott Baxter

  • Shipping and Receiving via CDMAWhether in shipping and receiving, or in CDMA, packaging is extremely important!Cargo is placed inside nested containers for protection and to allow addressingThe shipper packs in a certain order, and the receiver unpacks in the reverse orderCDMA containers are spreading codes

    RF100 (c) 1998 Scott Baxter

  • CDMAs Nested Spreading SequencesCDMA combines three different spreading sequences to create unique, robust channelsThe sequences are easy to generate on both sending and receiving ends of each linkWhat we do, we can undo

    RF100 (c) 1998 Scott Baxter

  • One of the CDMA Spreading Sequences:Walsh Codes64 Magic Sequences, each 64 chips longEach Walsh Code is precisely Orthogonal with respect to all other Walsh Codesits simple to generate the codes, ortheyre small enough to use from ROM WALSH CODES # ---------------------------------- 64-Chip Sequence ------------------------------------------ 0 0000000000000000000000000000000000000000000000000000000000000000 1 0101010101010101010101010101010101010101010101010101010101010101 2 0011001100110011001100110011001100110011001100110011001100110011 3 0110011001100110011001100110011001100110011001100110011001100110 4 0000111100001111000011110000111100001111000011110000111100001111 5 0101101001011010010110100101101001011010010110100101101001011010 6 0011110000111100001111000011110000111100001111000011110000111100 7 0110100101101001011010010110100101101001011010010110100101101001 8 0000000011111111000000001111111100000000111111110000000011111111 9 010101011010101001010101101010100101010110101010010101011010101010 001100111100110000110011110011000011001111001100001100111100110011 011001101001100101100110100110010110011010011001011001101001100112 000011111111000000001111111100000000111111110000000011111111000013 010110101010010101011010101001010101101010100101010110101010010114 001111001100001100111100110000110011110011000011001111001100001115 011010011001011001101001100101100110100110010110011010011001011016 000000000000000011111111111111110000000000000000111111111111111117 010101010101010110101010101010100101010101010101101010101010101018 001100110011001111001100110011000011001100110011110011001100110019 011001100110011010011001100110010110011001100110100110011001100120 000011110000111111110000111100000000111100001111111100001111000021 010110100101101010100101101001010101101001011010101001011010010122 001111000011110011000011110000110011110000111100110000111100001123 011010010110100110010110100101100110100101101001100101101001011024 000000001111111111111111000000000000000011111111111111110000000025 010101011010101010101010010101010101010110101010101010100101010126 001100111100110011001100001100110011001111001100110011000011001127 011001101001100110011001011001100110011010011001100110010110011028 000011111111000011110000000011110000111111110000111100000000111129 010110101010010110100101010110100101101010100101101001010101101030 001111001100001111000011001111000011110011000011110000110011110031 011010011001011010010110011010010110100110010110100101100110100132 000000000000000000000000000000001111111111111111111111111111111133 010101010101010101010101010101011010101010101010101010101010101034 001100110011001100110011001100111100110011001100110011001100110035 011001100110011001100110011001101001100110011001100110011001100136 000011110000111100001111000011111111000011110000111100001111000037 010110100101101001011010010110101010010110100101101001011010010138 001111000011110000111100001111001100001111000011110000111100001139 011010010110100101101001011010011001011010010110100101101001011040 000000001111111100000000111111111111111100000000111111110000000041 010101011010101001010101101010101010101001010101101010100101010142 001100111100110000110011110011001100110000110011110011000011001143 011001101001100101100110100110011001100101100110100110010110011044 000011111111000000001111111100001111000000001111111100000000111145 010110101010010101011010101001011010010101011010101001010101101046 001111001100001100111100110000111100001100111100110000110011110047 011010011001011001101001100101101001011001101001100101100110100148 000000000000000011111111111111111111111111111111000000000000000049 010101010101010110101010101010101010101010101010010101010101010150 001100110011001111001100110011001100110011001100001100110011001151 011001100110011010011001100110011001100110011001011001100110011052 000011110000111111110000111100001111000011110000000011110000111153 010110100101101010100101101001011010010110100101010110100101101054 001111000011110011000011110000111100001111000011001111000011110055 011010010110100110010110100101101001011010010110011010010110100156 000000001111111111111111000000001111111100000000000000001111111157 010101011010101010101010010101011010101001010101010101011010101058 001100111100110011001100001100111100110000110011001100111100110059 011001101001100110011001011001101001100101100110011001101001100160 000011111111000011110000000011111111000000001111000011111111000061 010110101010010110100101010110101010010101011010010110101010010162 001111001100001111000011001111001100001100111100001111001100001163 0110100110010110100101100110100110010110011010010110100110010110

    EXAMPLE:

    Correlation of Walsh Code #23 with Walsh Code #59

    #23 0110100101101001100101101001011001101001011010011001011010010110#59 0110011010011001100110010110011010011001011001100110011010011001Sum 0000111111110000000011111111000011110000000011111111000000001111

    Correlation Results: 32 1s, 32 0s: Orthogonal!! Unique Properties:Mutual Orthogonality

    RF100 (c) 1998 Scott Baxter

  • Other Sequences: Generation & PropertiesOther CDMA sequences are generated in shift registersPlain shift register: no fun, sequence = length of registerTapped shift register generates a wild, self-mutating sequence 2N-1 chips long (N=register length)Such sequences match if compared in step (no-brainer, any sequence matches itself)Such sequences appear approximately orthogonal if compared with themselves not exactly matched in timefalse correlation typically
  • Another CDMA Spreading Sequence:The Short PN CodeThe short PN code consists of two PN Sequences, I and Q, each 32,768 chips longGenerated in similar but differently-tapped 15-bit shift registersTheyre always used together, modulating the two phase axes of a QPSK modulator

    RF100 (c) 1998 Scott Baxter

  • Third CDMA Spreading Sequence: Long Code Generation & Masking to establish OffsetGenerated in a 42-bit register, the PN Long code is more than 40 days long (~4x1013 chips) -- too big to store in ROM in a handset, so its generated chip-by-chip using the scheme shown aboveEach handset codes its signal with the PN Long Code, but at a unique offset computed using its ESN (32 bits) and 10 bits set by the systemthis is called the Public Long Code Mask; produces unique shiftprivate long code masks are available for enhanced privacyIntegrated over a period even as short as 64 chips, phones with different PN long code offsets will appear practically orthogonal

    RF100 (c) 1998 Scott Baxter

  • Putting it All Together: CDMA ChannelsThe three spreading codes are used in different ways to create the forward and reverse linksA forward channel exists by having a specific Walsh Code assigned to the user, and a specific PN offset for the sectorA reverse channel exists because the mobile uses a specific offset of the Long PN sequence

    RF100 (c) 1998 Scott Baxter

  • Section BIS-95 CDMA Forward and Reverse Channels

    RF100 (c) 1998 Scott Baxter

  • How a BTS Builds the Forward Code Channels

    RF100 (c) 1998 Scott Baxter

  • Functions of the CDMA Forward ChannelsPILOT: WALSH CODE 0The Pilot is a structural beacon which does not contain a character stream. It is a timing source used in system acquisition and as a measurement device during handoffsSYNC: WALSH CODE 32This carries a data stream of system identification and parameter information used by mobiles during system acquisitionPAGING: WALSH CODES 1 up to 7There can be from one to seven paging channels as determined by capacity needs. They carry pages, system parameters information, and call setup ordersTRAFFIC: any remaining WALSH codesThe traffic channels are assigned to individual users to carry call traffic. All remaining Walsh codes are available, subject to overall capacity limited by noise

    RF100 (c) 1998 Scott Baxter

  • Code Channels in the Reverse Direction

    RF100 (c) 1998 Scott Baxter

  • Functions of the CDMA Reverse ChannelsThere are two types of CDMA Reverse Channels:TRAFFIC CHANNELS are used by individual users during their actual calls to transmit traffic to the BTSa reverse traffic channel is really just a user-specific public or private Long Code maskthere are as many reverse Traffic Channels as there are CDMA phones in the world!ACCESS CHANNELS are used by mobiles not yet in a call to transmit registration requests, call setup requests, page responses, order responses, and other signaling informationan access channel is really just a public long code offset unique to the BTS sectorAccess channels are paired to Paging Channels. Each paging channel can have up to 32 access channels.

    RF100 (c) 1998 Scott Baxter

  • Basic CDMA Network ArchitectureAccess Manageror (C)BSCSwitchBTSCh. CardTFU1GPSRCDSUCDSUSBSVocodersSelectorsCDSUCDSUCDSUCDSUCDSUCMSLMLPPLPPENETDTCsDMS-BUSTxcvrATxcvrBTxcvrCRFFEARFFEBRFFECTFUGPSRGPSGPSIOCPSTNCDSUDISCOCDSUDS0 in T1PacketsChipsRFChannelElementVocoder

    RF100 (c) 1998 Scott Baxter

  • Forward Traffic Channel: Generation Details from IS-95

    RF100 (c) 1998 Scott Baxter

  • Reverse Traffic Channel: Generation Details from IS-95

    RF100 (c) 1998 Scott Baxter

  • Section CIS-95 Operational DetailsVocoding, Multiplexing, Power Control

    RF100 (c) 1998 Scott Baxter

  • Variable Rate Vocoding & MultiplexingVocoders compress speech, reduce bit rate, greatly increasing capacityCDMA uses a superior Variable Rate Vocoderfull rate during speechlow rates in speech pausesincreased capacitymore natural soundVoice, signaling, and user secondary data may be mixed in CDMA frames

    RF100 (c) 1998 Scott Baxter

  • Forward Power ControlThe BTS continually reduces the strength of each users forward baseband chip stream When a particular handset sees errors on the forward link, it requests more energyThe complainers chip stream gets a quick boost; afterward, continues to diminishEach network manufacturer uses FER-based triggers and initial, minimum, and maximum traffic channel DGU values

    RF100 (c) 1998 Scott Baxter

  • Reverse Power ControlThree methods work in tandem to equalize all handset signal levels at the BTSReverse Open Loop: handset adjusts power up or down based on received BTS signal (AGC)Reverse Closed Loop: Is handset too strong? BTS tells up or down 1 dB 800 times/secondReverse Outer Loop: BSC has FER trouble hearing handset? BSC adjusts BTS setpoint

    RF100 (c) 1998 Scott Baxter

  • Details of Reverse Link Power ControlTXPO Handset Transmit PowerActual RF power output of the handset transmitter, including combined effects of open loop power control from receiver AGC and closed loop power control by BTScant exceed handsets maximum (typ. +23 dBm)

    TXGA Transmit Gain AdjustSum of all closed-loop power control commands from the BTS since the beginning of this callTypical TXPO:+23 dBm in a coverage hole0 dBm near middle of cell-50 dBm up close to BTS TXPO = -(RXdbm) -C + TXGAC = +73 for 8K vocoder systems= +76 for 13K vocoder systems

    RF100 (c) 1998 Scott Baxter

  • Section DA Quick Introduction to CDMA Messages and Call Processing

    RF100 (c) 1998 Scott Baxter

  • Messages in CDMAIn CDMA, most call processing events are driven by messagesSome CDMA channels exist for the sole purpose of carrying messages; they never carry users voice trafficSync Channel (a forward channel)Paging Channel (a forward channel)Access Channel (a reverse channel)On these channels, there are only messages, continuously all of the timeSome CDMA channels exist just to carry user trafficForward Traffic ChannelReverse Traffic ChannelOn these channels, most of the time is filled with traffic and messages are sent only when there is something to doAll CDMA messages have very similar structure, regardless of the channel on which they are sent

    RF100 (c) 1998 Scott Baxter

  • How CDMA Messages are SentCDMA messages on both forward and reverse traffic channels are normally sent via dim-and-burstMessages include many fields of binary dataThe first byte of each message identifies message type: this allows the recipient to parse the contentsTo ensure no messages are missed, all CDMA messages bear serial numbers and important messages contain a bit requesting acknowledgmentMessages not promptly acknowledged are retransmitted several times. If not acknowledged, the sender may release the callField data processing tools capture and display the messages for studyMSG_TYPE (00000110)ACK_SEQMSG_SEQACK_REQENCRYPTIONERRORS_DETECTEDPOWER_MEAS_FRAMESLAST_HDM_SEQNUM_PILOTSPILOT_STRENGTHRESERVED (0s)833125102460-7NUM_PILOTS occurrences of this field:FieldLength (in bits)EXAMPLE: A POWER MEASUREMENT REPORT MESSAGEt

    RF100 (c) 1998 Scott Baxter

  • Message Vocabulary: Acquisition & Idle States

    RF100 (c) 1998 Scott Baxter

  • Message Vocabulary: Conversation State

    RF100 (c) 1998 Scott Baxter

  • Section ECDMA Handset ArchitectureCDMA Handoffs

    RF100 (c) 1998 Scott Baxter

  • Whats In a Handset? How does it work?

    RF100 (c) 1998 Scott Baxter

  • The Rake ReceiverEvery frame, handset uses combined outputs of the three traffic correlators (rake fingers)Each finger can independently recover a particular PN offset and Walsh codeFingers can be targeted on delayed multipath reflections, or even on different BTSsSearcher continuously checks pilots

    RF100 (c) 1998 Scott Baxter

  • CDMA Soft Handoff MechanicsCDMA soft handoff is driven by the handsetHandset continuously checks available pilotsHandset tells system pilots it currently seesSystem assigns sectors (up to 6 max.), tells handsetHandset assigns its fingers accordinglyAll messages sent by dim-and-burst, no muting!Each end of the link chooses what works best, on a frame-by-frame basis!Users are totally unaware of handoff

    RF100 (c) 1998 Scott Baxter

  • The Complete Rules of Soft HandoffThe Handset considers pilots in setsActive: pilots of sectors actually in useCandidates: pilots mobile requested, but not yet set up & transmitting by systemNeighbors: pilots told to mobile by system, as nearby sectors to checkRemaining: any pilots used by system but not already in the other sets (div. by PILOT_INC)Handset sends Pilot Strength Measurement Message to the system whenever:It notices a pilot in neighbor or remaining set exceeds T_ADDAn active set pilot drops below T_DROP for T_TDROP timeA candidate pilot exceeds an active by T_COMPThe System may set up all requested handoffs, or it may apply special manufacturer-specific screening criteria and only authorize someExercise: How does a pilot in one set migrate into another set, for all cases? Identify the trigger, and the messages involved.

    RF100 (c) 1998 Scott Baxter

  • Softer HandoffEach BTS sector has unique PN offset & pilot Handset will ask for whatever pilots it wantsIf multiple sectors of one BTS simultaneously serve a handset, this is called Softer HandoffHandset cant tell the difference, but softer handoff occurs in BTS in a single channel elementHandset can even use combination soft-softer handoff on multiple BTS & sectorsBSC

    Switch

    Sel.

    RF100 (c) 1998 Scott Baxter

  • What is Ec/Io?Ec/Iocleanness of the pilotforetells the readability of the associated traffic channelsguides soft handoff decisionsdigitally derived: ratio of good to bad energy seen by the search correlator at the desired PN offsetNever appears higher than Pilots percentage of serving cells transmitted energyCan be degraded by strong RF from other cells, sectorsImperfect orthogonality, other PNs are ~-20 dB.Can be degraded by noise

    RF100 (c) 1998 Scott Baxter

  • CDMA Call ProcessingSection F

    RF100 (c) 1998 Scott Baxter

  • Lets Acquire the System!Example 1

    RF100 (c) 1998 Scott Baxter

  • Find a Frequency with a CDMA RF Signal

    RF100 (c) 1998 Scott Baxter

  • How Idle Mobiles Choose CDMA CarriersAt turnon, Idle mobiles use proprietary algorithms to find the initial CDMA carrier intended for them to useWithin that CDMA signal, two types of paging channel messages could cause the idle mobile to choose another frequency: CDMA Channel List Message and GSRM

    RF100 (c) 1998 Scott Baxter

  • Find Strongest Pilot, Read Sync Channel

    RF100 (c) 1998 Scott Baxter

  • The Configuration MessagesAfter reading the Sync Channel, the mobile is now capable of reading the Paging Channel, which it now monitors constantlyBefore it is allowed to transmit or operate on this system, the mobile must collect a complete set of configuration messages Collection is a short process -- all configuration messages are repeated on the paging channel every 1.28 secondsThe configuration messages contain sequence numbers so the mobile can recognize if any of the messages have been freshly updated as it continues to monitor the paging channelAccess parameters message sequence numberConfiguration message sequence numberIf a mobile notices a changed sequence number, or if 600 seconds passes since the last time these messages were read, the mobile reads all of them again

    RF100 (c) 1998 Scott Baxter

  • Go to Paging Channel, Get ConfiguredRake FingersReference PNActive PilotKeep Rake finger(s) on strongest available PN, decode Walsh 1, and monitor the Paging ChannelNow were ready to operate!!

    RF100 (c) 1998 Scott Baxter

  • Two Very Important Configuration Messages

    RF100 (c) 1998 Scott Baxter

  • Four Additional Configuration Messages

    RF100 (c) 1998 Scott Baxter

  • Lets do an Idle Mode Handoff!Example 2

    RF100 (c) 1998 Scott Baxter

  • Idle Mode HandoffAn idle mobile always demodulates the best available signalIn idle mode, it isnt possible to do soft handoff and listen to multiple sectors or base stations at the same time -- the paging channel information stream is different on each sector, not synchronous -- just like ABC, NBC, CBS, and CNN TV news programs arent in word-sync for simultaneous viewingSince a mobile cant combine signals, the mobile must switch quickly, always enjoying the best available signalThe mobiles pilot searcher is constantly checking neighbor pilotsIf the searcher notices a better signal, the mobile continues on the current paging channel until the end of the current superframe, then instantly switches to the paging channel of the new signalThe system doesnt know the mobile did this! (Does NBCs Tom Brokaw know you just switched your TV to CNN?)On the new paging channel, if the mobile learns that registration is required, it re-registers on the new sector

    RF100 (c) 1998 Scott Baxter

  • Idle Mode on the Paging Channel: Meet the Neighbors, track the Strongest PilotEc/IoAll PN Offsets0032K512ChipsPN0-20Neighbor SetThe phones pilot searcher constantly checks the pilots listed in the Neighbor List MessageIf the searcher ever notices a neighbor pilot substantially stronger than the current reference pilot, it becomes the new reference pilot and the phone switches over to its paging channel on the next superframe.This is called an idle mode handoff.

    RF100 (c) 1998 Scott Baxter

  • Phone Operation on the Access ChannelA sectors Paging Channel announces 1 (typ) to 32 (max) Access Channels: PN Long Code offsets for mobiles to use if accessing the system. For mobiles sending Registration, Origination, Page ResponsesBase Station always listening!On the access channel, phones are not yet under BTS closed-loop power control!Phones access the BTS by probing at power levels determined by receive power and an open loop formulaIf probe not acknowledged by BTS within ACC_TMO (~400 mS.), phone will wait a random time (~200 mS) then probe again, stronger by PI db.There can be 15 max. (typ. 5) probes in a sequence and 15 max. (typ. 2) sequences in an access attemptmost attempts succeed on first probe!The Access Parameters message on the paging channel announces values of all related parameters

    RF100 (c) 1998 Scott Baxter

  • Lets Register!Example 3

    RF100 (c) 1998 Scott Baxter

  • RegistrationRegistration is the process by which an idle mobile lets the system know its awake and available for incoming callsthis allows the system to inform the mobiles home switch of the mobiles current location, so that incoming calls can be deliveredregistration also allows the system to intelligently page the mobile only in the area where the mobile is currently located, thereby eliminating useless congestion on the paging channels in other areas of the systemThere are many different conditions that could trigger an obligation for the mobile to registerthere are flags in the System Parameters Message which tell the mobile when it must register on the current system

    RF100 (c) 1998 Scott Baxter

  • An Actual RegistrationThe System Parameters Message tells all mobiles when they should register.This mobile notices that it is obligated to register, so it transmits a Registration Message.The base station confirms that the mobiles registration message was received. Were officially registered!

    RF100 (c) 1998 Scott Baxter

  • Lets Receive an incoming Call!Example 4

    RF100 (c) 1998 Scott Baxter

  • Receiving an Incoming CallAll idle mobiles monitor the paging channel to receive incoming calls.When an incoming call appears, the paging channel notifies the mobile in a General Page Message.A mobile which has been paged sends a Page Response Message on the access channel.The system sets up a traffic channel for the call, then notifies the mobile to use it with a Channel Assignment Message.The mobile and the base station notice each others traffic channel signals and confirm their presence by exchanging acknowledgment messages.The base station and the mobile negotiate what type of call this will be -- I.e., 13k voice, etc.The mobile is told to ring and given a calling line ID to display.When the human user presses the send button, the audio path is completed and the call proceeds.

    RF100 (c) 1998 Scott Baxter

  • An Actual Page and Page ResponseThe system pages the mobile, 615-330-0644.The base station confirms that the mobiles page response was received. Now the mobile is waiting for channel assignment,expecting a response within 12 seconds.The mobile responds to the page.

    RF100 (c) 1998 Scott Baxter

  • Channel Assignment and Traffic Channel ConfirmationOnly about 400 ms. after the base station acknowledgment order, the mobile receives the channel assignment message.The base station is already sending blank frames on the forward channel,using the assigned Walsh code.The mobile sees at least two good blank frames in a row on the forward channel, and concludes this is the right traffic channel. It sends a preamble of two blank frames of its own on the reverse traffic channel.The base station acknowledges receiving the mobiles preamble.The mobile station acknowledges the base stations acknowledgment.Everybody is ready!

    RF100 (c) 1998 Scott Baxter

  • Service Negotiation and Mobile AlertNow that both sides have arrived on the traffic channel, the base station proposes that the requested call actually begin.The mobile agrees and says its ready to play.The base station orders the mobile to ring, and gives it the calling partys number to display.18:14:48.018 Reverse Traffic Channel: Order ACK_SEQ: 1 MSG_SEQ: 4 ACK_REQ: 0ENCRYPTION: 0 Mobile Station Acknowledgement Order

    The mobile says its ringing.SERVICE CONNECT COMPLETE is a major milestone in call processing. Up until now, this was an access attempt. Now it is officially a call.

    RF100 (c) 1998 Scott Baxter

  • The Human Answers! Connect OrderThe mobile has been ringing for several seconds. The human user finally comes over and presses the send button to answer the call.Now the switch completes the audio circuit and the two callers can talk!

    RF100 (c) 1998 Scott Baxter

  • Lets make an Outgoing Call!Example 5

    RF100 (c) 1998 Scott Baxter

  • Placing an Outgoing CallThe mobile user dials the desired digits, and presses SEND.Mobile transmits an Origination Message on the access channel.The system acknowledges receiving the origination by sending a base station acknowledgement on the paging channel.The system arranges the resources for the call and starts transmitting on the traffic channel.The system notifies the mobile in a Channel Assignment Message on the paging channel.The mobile arrives on the traffic channel.The mobile and the base station notice each others traffic channel signals and confirm their presence by exchanging acknowledgment messages.The base station and the mobile negotiate what type of call this will be -- I.e., 13k voice, etc.The audio circuit is completed and the mobile caller hears ringing.

    RF100 (c) 1998 Scott Baxter

  • OriginationThe mobile sends an origination message on the access channel.The base station confirms that the origination message was received.The base station sends a Channel Assignment Message and the mobile goes to the traffic channel.

    RF100 (c) 1998 Scott Baxter

  • Traffic Channel Confirmation

    RF100 (c) 1998 Scott Baxter

  • Service Negotiation and Connect Complete

    RF100 (c) 1998 Scott Baxter

  • Lets End a Call!Example 6

    RF100 (c) 1998 Scott Baxter

  • Ending A CallA normal call continues until one of the parties hangs up. That action sends a Release Order, normal release. The other side of the call sends a Release Order, no reason given.If a normal release is visible, the call ended normally.At the conclusion of the call, the mobile reacquires the system.Searches for the best pilot on the present CDMA frequencyReads the Sync Channel MessageMonitors the Paging Channel steadilySeveral different conditions can cause a call to end abnormally:the forward link is lost at the mobile, and a fade timer actsthe reverse link is lost at the base station, and a fade timer actsa number of forward link messages arent acknowledged, and the base station acts to tear down the linka number of reverse link messages arent acknowledged, and the mobile station acts to tear down the link

    RF100 (c) 1998 Scott Baxter

  • A Beautiful End to a Normal CallAt the end of a normal call, this mobile user pressed end.The mobile left the traffic channel, scanned to find the best pilot, and read the Sync Channel Message.The base station acknowledged receiving the message, then sent a release message of its own.

    RF100 (c) 1998 Scott Baxter

  • Lets receive Notificationof a Voice Message!Example 7

    RF100 (c) 1998 Scott Baxter

  • Feature Notification98/06/30 21:16:44.368 [PCH] Feature Notification MessageMSG_LENGTH = 144 bitsMSG_TYPE = Feature Notification MessageACK_SEQ = 0MSG_SEQ = 0ACK_REQ = 1VALID_ACK = 0ADDR_TYPE = IMSIADDR_LEN = 56 bitsIMSI_CLASS = 0IMSI_CLASS_0_TYPE = 3RESERVED = 0MCC = 302IMSI_11_12 = 00IMSI_S = 9055170325RELEASE = 0RECORD_TYPE = Message WaitingRECORD_LEN = 8 bitsMSG_COUNT = 1RESERVED = 0

    FEATURE NOTIFICATION MESSAGEThe Feature Notification Message on the Paging Channel tells a specific mobile it has voice messages waiting.

    There are other record types to notify the mobile of other features.The mobile confirms it has received the notification by sending a Mobile Station Acknowledgment Order on the access channel.MOBILE STATION ACKNOWLEDGMENT

    RF100 (c) 1998 Scott Baxter

  • Lets do a Handoff!Example 8

    RF100 (c) 1998 Scott Baxter

  • The Call is Already Established. What Next?Ec/IoAll PN Offsets0032K512ChipsPN0-20Neighbor SetThe call is already in progress. PN 168 is the only active signal,and also is our timing reference.Continue checking the neighbors.If we ever notice a neighbor with Ec/Io above T_ADD,ask to use it! Send a Pilot Strength Measurement Message!T_ADD107521683200250014080220!!

    RF100 (c) 1998 Scott Baxter

  • Mobile Requests the Handoff!Just prior to this message, this particular mobile already was in handoff with PN 168 and 220. This pilot strength measurement message reports PN 500 has increased above T_Add, and the mobile wants to use it too.The base station acknowledges receiving the Pilot Strength Measurement Message.

    RF100 (c) 1998 Scott Baxter

  • System Authorizes the Handoff!The base station sends a Handof Direction Message authorizing the mobile to begin soft handoff with all three requested PNs. The pre-existing link on PN 168 will continue to use Walsh code 61, the new link on PN220 will use Walsh Code 20, and the new link on PN500 will use Walsh code 50.The mobile acknowledges it has received the Handoff Direction Message.

    RF100 (c) 1998 Scott Baxter

  • Mobile Implements the Handoff!The mobile searcher quickly re-checks all three PNs. It still hears their pilots!The mobile sends a Handoff Completion Message, confirming it still wants to go ahead with the handoff.BASE STATION ACKNOWLEDGMENT98/05/24 23:14:02.985 [RTC] Handoff Completion MessageMSG_LENGTH = 72 bits MSG_TYPE = Handoff Completion MessageACK_SEQ = 6 MSG_SEQ = 1 ACK_REQ = 1ENCRYPTION = Encryption Mode DisabledLAST_HDM_SEQ = 0PILOT_PN = 168 Offset IndexPILOT_PN = 220 Offset IndexPILOT_PN = 500 Offset IndexRESERVED = 0HANDOFF COMPLETION MESSAGEThe base station confirms it has received the mobiles Handoff Completion message, and will continue with all of the links active.98/05/24 23:14:03.085 [FTC] Forward Traffic Channel: Order ACK_SEQ: 0 MSG_SEQ: 1 ACK_REQ: 0 ENCRYPTION: 0 USE_TIME: 0 ACTION_TIME: 0 Base Station Acknowledgement Order

    RF100 (c) 1998 Scott Baxter

  • Neighbor List Updated, Handoff is Complete!In response to the mobiles Handoff Completion Message, the base station assembles a new composite neighbor list including all the neighbors of each of the three active pilots.This is necessary since the mobile could be traveling toward any one of these pilots and may need to request soft handoff with any of them soon.The mobile confirms receiving the Neighbor List Update Message. It is already checking the neighbor list and will do so continuously from now on.The handoff is fully established.

    RF100 (c) 1998 Scott Baxter

  • Handoff Now In Effect, but still check Pilots!

    RF100 (c) 1998 Scott Baxter

  • The Complete Picture of Handoff & Pilot Sets

    RF100 (c) 1998 Scott Baxter

  • Deeper Handoff Details:Search Windows & TimingSection G

    RF100 (c) 1998 Scott Baxter

  • The Pilot Searchers Measurement Process

    RF100 (c) 1998 Scott Baxter

  • A Quick Primer on Pilot Search WindowsThe phone chooses one strong sector and locks to it, accepting its offset at face value and interpreting all other offsets by comparison to itIn messages, system gives to handset a neighbor list of nearby sectors PNsPropagation delay skews the apparent PN offsets of all other sectors, making them seem earlier or later than expectedTo overcome skew, when the phone searches for a particular pilot, it scans an extra wide delta of chips centered on the expected offset (called a search window) Search window values can be datafilled individually for each Pilot set:There are pitfalls if the window sizes are improperly settoo large: search time increasestoo small: overlook pilots from far awaytoo large: might misinterpret identity of a distant BTS signal One chip is 801 feet or 244.14 m1 mile=6.6 chips; 1 km.= 4.1 chips

    RF100 (c) 1998 Scott Baxter

  • Setting Pilot Search Window SizesWhen the handset first powers up, it does an exhaustive search for the best pilot. No windows are used in this process.On the paging channel, the handset learns the window sizes SRCH_WIN_A, N, R and uses them when looking for neighbors both in idle mode and during calls.When a strong neighbor is requested in a PSMM, the former neighbor pilot is now a candidate. Its offset is precisely remembered and frequently rechecked and tracked by the phone.Window size for actives and candidates can be small, since their exact position is known. Only search wide enough to include multipath energy!This greatly speeds up overall searching!Most post-processing tools deliver statistics on the spread (in chips) between fingers locked to the same pilot. These statistics literally show us how wide the SRCH_WIN_A should be set.Neighbor and Remaining search windows should be set to accommodate the maximum intercell distances which a mobile might experience

    RF100 (c) 1998 Scott Baxter

  • Handoff Problems: Window Dropped CallsCalls often drop when strong neighbors suddenly appear outside the neighbor search window and cannot be used to establish soft handoff.Neighbor Search Window SRCH_WIN_N should be set to a width at least twice the propagation delay between any site and its most distant neighbor site Remaining Search Window SRCH_WIN_R should be set to a width at least twice the propagation delay between any site and another site which might deliver occasional RF into the service area

    RF100 (c) 1998 Scott Baxter

  • Overall Handoff PerspectiveSoft & Softer Handoffs are preferred, but not always possiblea handset can receive BTS/sectors simultaneously only on one frequency all involved BTS/sectors must connect to a networked BSCs. Some manufacturers do not presently support this, and so are unable to do soft-handoff at boundaries between BSCs.frame timing must be same on all BTS/sectorsIf any of the above are not possible, handoff still can occur but can only be hard break-make protocol like AMPS/TDMA/GSMintersystem handoff: hardchange-of-frequency handoff: hardCDMA-to-AMPS handoff: hard, no handbackauxiliary trigger mechanisms available (RTD)

    RF100 (c) 1998 Scott Baxter

  • Section HCDMA Network Architecture

    RF100 (c) 1998 Scott Baxter

  • Structure of a Typical Wireless SystemBASE STATIONCONTROLLERSUPPORTFUNCTIONSBASE STATIONSMobile TelephoneSwitching OfficePSTNLocal CarriersLong DistanceCarriersATM Linkto other CDMANetworks(Future)Voice Mail SystemSWITCHHLR Home Location Register(subscriber database)

    RF100 (c) 1998 Scott Baxter

  • Signal Flow: Two-Stage MetamorphosisBSC-BSMMTXBTSCh. CardTFU1GPSRCDSUCDSUSBSVocodersSelectorsCDSUCDSUCDSUCDSUCDSUCMSLMLPPLPPENETDTCsDMS-BUSTxcvrATxcvrBTxcvrCRFFEARFFEBRFFECTFUGPSRGPSGPSIOCPSTNCDSUDISCOCDSUDS0 in T1PacketsChipsRFChannelElementVocoder

    RF100 (c) 1998 Scott Baxter

  • Nortel CDMA Network Architecturewww.nortel.com

    RF100 (c) 1998 Scott Baxter

  • NORTEL CDMA System Architecture

    RF100 (c) 1998 Scott Baxter

  • Switch: The Nortel MTXPrimary functionsCall ProcessingMobility ManagementHLR-VLR accessIntersystem call delivery (IS-41C)Inter-MTX handover (IS-41C)Billing Data CaptureCalling Features & ServicesCollecting System OMs, PegsHigh reliability, redundancyMTXCMSLMLPPENETDTCsDMS-BUSPSTN & Other MTXsCDMABSCUnch. T1IOCCDMASBSMAP,VDUsBillingLPPCCS7Ch.T1ChT1

    RF100 (c) 1998 Scott Baxter

  • The Nortel BSCPrimary functionsvocodingsoft handoff managementFER-based power controlrouting of all traffic and control packetsScaleable architectureexpand SBS to keep pace with traffic growthexpandable DISCO

    RF100 (c) 1998 Scott Baxter

  • The Nortel BTSBase Transceiver StationPrimary function: Air link generate, radiate, receive CDMA RF signal IS-95/J.Std. 8high-efficiency T1 backhaultest capabilitiesConfigurations1, 2, or 3 sectors800 MHz.: indoor1900 MHz.: self-contained outdoor, remotable RFFEsnew 1900 MHz. indoor, 800 MHz. & 1900 MHz. multi-carrier options

    RF100 (c) 1998 Scott Baxter

  • The Nortel BSMBase Station ManagerPrimary functions: OA&M for CDMA componentsConfiguration managementBSC, BTS configuration and parametersFault managementAlarm ReportingPerformance managementinterface for CDMA statistics and peg counts collectionSecurity managementUnix-based

    RF100 (c) 1998 Scott Baxter

  • Summary of CDMA Capacity Considerations

    RF100 (c) 1998 Scott Baxter

  • Lucent CDMA Network Architecturewww.lucent.com

    RF100 (c) 1998 Scott Baxter

  • Lucent CDMA System Architecture5ESS-2000 DCSECPBTSChannelUnitClusterPSTN & Other MTXsExecutiveCellular Processor Complex (ECPC)Circuit Switch PlatformCDMA SpeechHandling EquipmentPacket SwitchPlatform

    RF100 (c) 1998 Scott Baxter

  • The Lucent ECPExecutive Cellular ProcessorPrimary functionsCall ProcessingMobility ManagementHLR-VLR accessIntersystem call delivery (IS-41C)Inter-MTX handover (IS-41C)Billing Data CaptureCalling Features & ServicesCollecting System OMs, PegsHigh reliability, redundancy

    RF100 (c) 1998 Scott Baxter

  • The Lucent #5ESS and Access ManagerPrimary functionsvocodingsoft handoff managementFER-based power controlrouting of all traffic and control packetsScaleable architectureexpand speech handlersexpandable packet switch

    RF100 (c) 1998 Scott Baxter

  • The Lucent BTSPrimary function: Air link generate, radiate, receive CDMA RF signal IS-95/J.Std. 8high-efficiency T1 backhaultest capabilities

    RF100 (c) 1998 Scott Baxter

  • Motorola CDMA Network Architecturewww.motorola.com

    RF100 (c) 1998 Scott Baxter

  • Motorola CDMA System ArchitectureOMC-RCBSCPCSCPersonalCommunicationsSwitchingCenterPSTNDSCEMX-2500orEMX-5000Mobility ManagerTranscoderOMC-RProcessorApplicationProcessor(or SC-UNO)BTS (SC9600/4800/2400)Group LineInterface (GLI)MultichannelCDMA Card (MCC)BTS (SC614T/611)MotorolaAdvancedWidebandInterface(MAWI)PCLocalMaintenanceFacility

    RF100 (c) 1998 Scott Baxter

  • The Motorola PCSCPersonal Communications Switching CenterPrimary functionsCall ProcessingHLR-VLR accessIntersystem call delivery (IS-41C)Billing Data CaptureCalling Features & ServicesPSTNDSCEMX-2500orEMX-5000EMX-2500EMX-5000

    RF100 (c) 1998 Scott Baxter

  • The Motorola CBSCCentralized Base Station ControllerMobility Managerallocation of BTS resourceshandoff managementCall management & supervision Transcodervocodingsoft handoff managementFER-based power controlrouting of all traffic and control packets

    CBSCMobility ManagerTranscoder

    RF100 (c) 1998 Scott Baxter

  • The Motorola BTS FamilyPrimary function: Air link generate, radiate, receive CDMA RF signal IS-95/J.Std. 8high-efficiency T1 backhaultest capabilities

    BTS (SC9600/4800/2400)Group LineInterface (GLI)MultichannelCDMA Card (MCC)BTS (SC614T/611)MotorolaAdvancedWidebandInterface(MAWI)PCLocalMaintenanceFacilitySC614T

    RF100 (c) 1998 Scott Baxter

  • Section IIntroduction to Optimization

    RF100 (c) 1998 Scott Baxter

  • Introduction to OptimizationCourse RF200 provides detailed information on CDMA system performance optimization, and is intended for all personnel who are responsible for improving system performance. RF200 presents:Performance Indicators and Problem Signatures analysisReview of tools and stats available on the systemReview of mobile tools and how to interpret test drive dataHow to analyze drive-test data with post-processing toolsReal-life examples of problems for hands-on analysisOptimization is important enough that everyone should understand what it is and how it is usually performed. The following slides provide a general perspective on optimization and are intended for everyone with technical responsibilities, even if not directly involved in performance optimization

    RF100 (c) 1998 Scott Baxter

  • System Performance OptimizationThe term System Performance Optimization really includes three distinct types of activities:Optimization of a New System or New Cellsexamining parameters, neighbor lists, and cell configuration to ensure that blatant errors are eliminated and normal operation is achieved as verified in drive testsMinimization of Operating Problems on Existing Systemsidentifying problems from system statistics, drive tests, and customer complaintsreducing dropped calls, access failures, trouble spotsCapacity Enhancementwatching system capacity indicators and optimizing adjustable parameters to achieve the best possible capacity, consistent with acceptable levels of dropped calls and access failures

    RF100 (c) 1998 Scott Baxter

  • Department Store Analogy: Tops-Down, Bottoms-UpSome things are easier to measure from the customer side!

    RF100 (c) 1998 Scott Baxter

  • Aeronautical Analogy: Tools for Problem InvestigationTo study the cause of an aeronautical accident, we try to recover the Flight Data Recorder and the Cockpit Voice Recorder.To study the cause of a CDMA call processing accident, we review data from the Temporal Analyzer and the Layer 3 Message Files -- for the same reasons.

    RF100 (c) 1998 Scott Baxter

  • Starting Optimization on a New SystemRF Coverage Controltry to contain each sectors coverage, avoiding gross spillover into other sectorstools: PN Plots, Handoff State Plots, Mobile TX plotsSearch Window Settingsfind best settings for SRCH_WIN_A, _N, _Respecially optimize SRCH_WIN_A per sector using collected finger separation data; has major impact on pilot search speedNeighbor List Tuningtry to groom each sectors neighbors to only those necessary but be alert to special needs due to topography and traffictools: diagnostic data, system logsAccess Failures, Dropped Call Analysisfinally, iterative corrections until within numerical goals Getting these items into shape provides a solid baseline and foundation from which future performance issues can be addressed.

    RF100 (c) 1998 Scott Baxter

  • Solving Problems on Existing SystemsCDMA optimization is very different from optimization in analog technologies such as AMPSAMPS: a skilled engineer with a handset or simple equipment can hear, diagnose, and correct many common problemsco-channel, adjacent channel, external interferencesdragged handoffs, frequency plan problemsCDMA impairments have one audible symptom: Dropped Callvoice quality remains excellent with perhaps just a hint of garbling even as the call approaches dropping in a hostile RF environmentSuccessful CDMA Optimization requires:recognition and understanding of common reasons for call failurecapture of RF and digital parameters of the call prior to dropanalysis of call flow, checking messages on both forward and reverse links to establish what happened, where, and why

    RF100 (c) 1998 Scott Baxter

  • CDMA Problems Attacked in OptimizationExcessive Access Failurestypical objectives:
  • Sources of CDMA Data and Tools for ProcessingCDMA optimization data flows from three places:SwitchCDMA peripherals (CBSC & BTS)HandsetEach stream of data has a family of software and hardware tools for collection and analysisData AnalysisPost-ProcessingToolsIS-95/J-STD-008 MessagesIS-95/J-STD-8 MessagesSwitch Datapegs, logsMobile DataPost-ProcessingToolsMobile Data Capture ToolsHandsetMessagesExternalAnalysisToolsPC-basedPC-basedUnix-based,PC-basedVariousCDMA NETWORK EQUIPMENTHANDSETSystem Internal Messages

    RF100 (c) 1998 Scott Baxter

  • CDMA Field Test ToolsField Collection Tools using Handset DataThere are many commercial CDMA field test toolsCharacteristics of many test tools:capture data from data ports on commercial handsetslog data onto PCs using proprietary softwarecan display call parameters, messaging, graphs, and mapsstore data in formats readable for post-processing analysissmall and portable, easy to use in vehicles or even on footA few considerations when selecting test tools:does it allow integration of network and mobile data?Cost, features, convenience, availability, and supportnew tools are introduced every few months - investigate!

    QualcommGraysonComarcoSAFCOLCCMotorolaPN ScannersHewlett-PackardHewlett-PackardBerkeleyVaritronicsGraysonQualcomm

    RF100 (c) 1998 Scott Baxter

  • Qualcomms MDM: Mobile Diagnostic MonitorQualcomms Mobile Diagnostic Monitor CDMA handset (customer provided)Proprietary connecting cablePC software for collection and field pre-analysisTemporal analyzer display modeMessaging

    RF100 (c) 1998 Scott Baxter

  • Grayson Electronics Mobile Collection ToolsWireless Measurement Instrumentone hardware platform, can contain up to 4 receivers, handsets, scanners, and other devicesInspector32 PC collection softwarenumerous output formats & exporting - ASCII messages, database, temporal datasimultaneous display of parameters, map location, messaging, PN scannerAnalyzerTM post-processing software call event statistics, parameters, performance indicators as map icons, graphs, and spreadsheet tablesmessage display window synched with maps and graphscan search for events, messagescan study multiple drive files at once

    RF100 (c) 1998 Scott Baxter

  • LCC, SAFCO and Comarco Mobile ToolsLCC:RSAT2000 mobile collectionCollect2000 PC collection softwareDeskCAT post-processing SoftwareSAFCO (no photo available)Mobile PC collection toolPortable pen-based PC toolOPAS post-analysis software COMARCO:NES-series units / PC collectionFile formats for post-processinglatest models include L3 messagingComarcoLCC

    RF100 (c) 1998 Scott Baxter

  • PN ScannersPN Scanners are faster than phones and more reliable finding rogue pilotsBerkeley Varitronics (GPS-referenced)full-PN scan speed 26-2/3 ms.2048 parallel processors for very fast detection of transient interferorsHewlett-Packard (GPS-referenced)full-PN scan speed 1.2 sec.Integrated with spectrum analyzer and phone call-processing toolQualcomm (BTS-referenced)lowest-cost solutionalso acts as test phone with user-set T_Add, T_Drop, etc.Grayson Wireless (BTS-referenced)scan speed 6.3 sec.integrated with phone & call-processing data collection toola high-end version is also available using Berkeley Scanner (GPS-locked)

    RF100 (c) 1998 Scott Baxter

  • Handsets as Tools: Simple but always Available!Most CDMA handsets provide some form of maintenance display (Debug Mode) as well as instrumentation accessall CDMA drive-test tools use handsets as their front-endsUsing the handset as a manual tool without Commercial Test Tools:Enter the maintenance mode by special sequence of keystrokesDisplayed ParametersPN Offset, Handset Mode, Received RF Level , Transmit Gain AdjustMaintenance Display Applicationsbest serving cell/sectorsimple call debugging (symptoms of weak RF, forward link interference, etc.)Handset Limitations during manual observationno memory: real-time observations only; no access to messages or call details; serving PN offset not updated during voice calls

    RF100 (c) 1998 Scott Baxter

  • Entering QCP-800/QCP-1900 Maintenance DisplayMenu401See following legend for maintenance display values(* or correct code, if different)Press This:See This:continue:See This:**

    RF100 (c) 1998 Scott Baxter

  • Entering QCP-820/QCP-2700 Maintenance DisplayEnter 111111Hold the jog dial inNavigate to the Debug ScreenEnter the access code (normally 000000)you will see the same display screens and options as in the earlier QCP phones

    RF100 (c) 1998 Scott Baxter

  • Interpreting the QCP Maintenance Display

    RF100 (c) 1998 Scott Baxter

  • Lucent Maintenance Display on QCP PhonesLucent systems can display site-specific maintenance data during calls on CDMA phones (using data burst short messages) by this procedure:Enter the local test number for maintenance use765-3421 [TALK]you will hear a dial toneEnter *426 [TALK]you will hear a dial toneobserve display as shownPress * [CLEAR] repeatedly to cycle through the channel elements within the sectorCaution - Information Unverified

    RF100 (c) 1998 Scott Baxter

  • The Sanyo Dual-Band Phonepress menu 7, 0enter in DEBUGM (332846) screens are similar to QCP phones70Press This:Menu

    RF100 (c) 1998 Scott Baxter

  • Entering the Samsung Maintenance Display801See following legend for maintenance display values(* or correct code, if different)Press This:See This:continue:See This:**Menu

    RF100 (c) 1998 Scott Baxter

  • Interpreting Samsung Maintenance Display:Acquisition, Idle, and Access States

    RF100 (c) 1998 Scott Baxter

  • Interpreting Samsung Maintenance Display:Traffic Channel State

    RF100 (c) 1998 Scott Baxter

  • Entering Denso Touchpoint Debug ModeEnter ##DEBUG (##33284)Scroll down to SAVEPress OKHighlight SERVICE SCREENPress OK

    If you want to make a test call, dial the digits and press OK while in idle mode

    RF100 (c) 1998 Scott Baxter

  • Denso Touchpoint Maintenance DisplayCharging Battery VoltageAverage Battery VoltageAverage Battery TemperatureSystem IDNetwork IDRF Channel FrequencyDigital PN OffsetReceived Signal StrengthEstimated Transmitter Power OutputNumber of Bad FramesNumber of Good FramesFrame Erasure Rate, PercentBase Station coordinatesCurrent status of Rake FingersActive Pilot SetCandidate Pilot SetNeighbor Pilot Set

    RF100 (c) 1998 Scott Baxter

  • Entering Maintenance Mode: MotorolaMotorola phones must be enabled for maintenance mode. Normal customer phones are not pre-enabled to enter maintenance mode.To Enter Maintenance Mode:Press FCN 00**83786633 STO; Phone will display US Enter 55#Press * to step to number 9Enter 01000000, Press STOPower cycle phone -- Test mode is now enabled!To access the screens:Press FCN FCN (Phone should now say "Old Markov Call")Use volume keys or * or # keys, scroll to "Call Status Mode OffPress Smart Button (between volume keys) to enable screenPress END You should now be in Call Status Mode!Nice display includes active PNs, Ec/Io, etc.

    RF100 (c) 1998 Scott Baxter

  • Motorola Maintenance Display3720653003841681850IDLMR082-04001270013V0183000106Current SIDCurrent NIDCall CounterStrongest ActivePNEc/Io# Active# Cand.Strongest NeighborCurrent RSSIDropped Call Counter# NeighborsCurrent RF ChannelCurrent FERCurrent TX dbm

    RF100 (c) 1998 Scott Baxter

  • Entering the Nokia Maintenance DisplayEnter *3001#12345 MENUScroll down to Field testPress SelectScroll up to EnabledPress OKPower the phone off and onYou should now be in Field test mode

    RF100 (c) 1998 Scott Baxter

  • Maintenance Display Screens of Nokia HandsetsCSSTXXXXXRSSICCCCRXTXScreen 1: GeneralMobile MINMobile Station ESNPreferred Sys 1=AMPS, 2=CDMAOwnNumberESNPAOperator Selected(1=A, 2=B, 3=bothScreen 4: NAM InfoPrimary Channel ASecondary Channel APPCASPCAScreen 5: NAM InfoPrimary Channel BSecondary Channel BPPCBSPCBLocal UseAccess Overload ClassLACurrent SIDCurrent NIDSIDNIDScreen 6: BS & Access. Info.DBUS (Handsfree?)DBUSBASE_ID (sys par msg)P_REV (sync msg)BASE#P_REVScreen 7: BS Protocol Rev. LevelMIN_P_REV (sync msg.MIN_P_REVCS StateDate from System TimeCSSTMMDDYYScreen 8: Time InformationSystem TimeHHMMSSThe following screens appear in field test mode on Nokia HD881 series of Handsets:

    RF100 (c) 1998 Scott Baxter

  • Nokia Maintenance Display Screens (continued)TADDTDROPTATDScreen 9: Acquisition InformationTCOMPTCTTDROPTTActive WindowWW1Neighbor WindowWW2Remaining WindowWW3Pilot PN OffsetEc/Io in 1/2 db unitsPPNECScreen 10: Active Set (#1-3) Keep? 1KPilot PN OffsetEc/Io in 1/2 db unitsPPNECKeep? 1KPilot PN OffsetEc/Io in 1/2 db unitsPPNECKeep? 1KPilot PN OffsetEc/Io in 1/2 db unitsPPNECScreen 11: Active Set (#4-6)Keep? 1KPilot PN OffsetEc/Io in 1/2 db unitsPPNECKeep? 1KPilot PN OffsetEc/Io in 1/2 db unitsPPNECKeep? 1K

    RF100 (c) 1998 Scott Baxter

  • Nokia Maintenance Display Screens (continued)NBR 1 PN OffsetEc/Io in 1/2 db unitsPPNECScreen 12: Neighbor Set (#1-5) NBR 2 PN OffsetEc/Io in 1/2 db unitsPPNECNBR 3 PN OffsetEc/Io in 1/2 db unitsPPNECNBR 4 PN OffsetEc/Io in 1/2 db unitsPPNECNBR 5 PN OffsetEc/Io in 1/2 db unitsPPNECNBR 6 PN OffsetEc/Io in 1/2 db unitsPPNECScreen 13: Neighbor Set (#6-10) NBR 7 PN OffsetEc/Io in 1/2 db unitsPPNECNBR 8 PN OffsetEc/Io in 1/2 db unitsPPNECNBR 9 PN OffsetEc/Io in 1/2 db unitsPPNECNBR 10 PN OffsetEc/Io in 1/2 db unitsPPNECNBR 11 PN OffsetEc/Io in 1/2 db unitsPPNECScreen 14: Neighbor Set (#1-5) NBR 12 PN OffsetEc/Io in 1/2 db unitsPPNECNBR 13 PN OffsetEc/Io in 1/2 db unitsPPNECNBR 14 PN OffsetEc/Io in 1/2 db unitsPPNECNBR 15 PN OffsetEc/Io in 1/2 db unitsPPNECNBR 16 PN OffsetEc/Io in 1/2 db unitsPPNECScreen 15: Neighbor Set (#16-20) NBR 17 PN OffsetEc/Io in 1/2 db unitsPPNECNBR 18 PN OffsetEc/Io in 1/2 db unitsPPNECNBR 19 PN OffsetEc/Io in 1/2 db unitsPPNECNBR 20 PN OffsetEc/Io in 1/2 db unitsPPNEC

    RF100 (c) 1998 Scott Baxter

  • Nokia Maintenance Display Screens (continued)CAND 1 PN OffsetEc/Io in 1/2 db unitsPPNECScreen 16: Candidate Set (#1-5) CAND 2 PN OffsetEc/Io in 1/2 db unitsPPNECCAND 3 PN OffsetEc/Io in 1/2 db unitsPPNECCAND 4 PN OffsetEc/Io in 1/2 db unitsPPNECCAND 5 PN OffsetEc/Io in 1/2 db unitsPPNECTask NameWorst-Cs Stack Free SpTASKNFREEScreen 17-22: Task Stack Ck InfoOverflow ind. by shift2=sys stack overflowTask StackSys StackScreen 23: Stack Status Info.Screen 24: Codec Registers

    RF100 (c) 1998 Scott Baxter

  • BibliographyWireless Communications Principles & Practice by Theodore S. Rappaport. 641 pp., 10 chapters, 7 appendices. Prentice-Hall PTR, 1996, ISBN 0-13-375536-3. If you can only buy one book, buy this one. Comprehensive summary of wireless technologies along with principles of real systems. Includes enough math for understanding and solving real problems. Good coverage of system design principles.

    The Mobile Communications Handbook edited by Jerry D. Gibson. 577 pp., 35 chapters. CRC Press/ IEEE Press 1996, ISBN 0-8493-0573-3. $89 If you can buy only two books, buy this second. Solid foundation of modulation schemes, digital processing theory, noise, vocoding, forward error correction, excellent full-detailed expositions of every single wireless technology known today, RF propagation, cell design, traffic engineering. Each chapter is written by an expert, and well-edited for readability. Clear-language explanations for both engineers and technicians but also includes detailed mathematics for the research-inclined. Highly recommended.

    CDMA Systems Engineering Handbook by Jhong Sam Lee and Leonard E. Miller, 1998 Artech House, ISBN 0-89006-990-5. Excellent treatment of CDMA basics and deeper theory, cell and system design principles, system performance optimization and capacity issues. Highly recommended.

    Applications of CDMA in Wireless/Personal Communications by Garg, Smolik & Wilkes. 360 pp., Prentice Hall, 1997, ISBN 0-13-572157-1 $65. Good CDMA treatment. Excellent treatment of IS-95/JStd. 008 as well as W-CDMA. More than just theoretical text, includes chapters on IS-41 networking, radio engineering, and practical details of CDMA signaling, voice applications, and data applications.

    CDMA RF System Engineering by Samuel C. Yang, 1998 Artech House, ISBN 0-89006-991-3. Good general treatment of CDMA capacity considerations from mathematical viewpoint.

    "CDMA: Principles of Spread Spectrum Communication" by Andrew J. Viterbi. 245 p. Addison-Wesley 1995. ISBN 0-201-63374-4, $65. Definitive very deep CDMA Theory. You can design CDMA chipsets after reading it, but beware lots of triple integrals; not very relevant to operations. Prestige collectors item among CDMA faithful.

    "Mobile Communications Engineering" 2nd. Edition by William C. Y. Lee. 689 pp. McGraw Hill 1998 $65. ISBN 0-07-037103-2 Lees latest/greatest reference work on all of wireless; very complete and well done.

    "Spread Spectrum Communications Handbook" by Simon, Omura, Scholtz, and Levitt. 1227 pp., 15 illus., McGraw-Hill # 057629-7, $99.50 Definitive technical reference on principles of Spread Spectrum including direct sequence as used in commercial IS-95/JStd008 CDMA. Heavy theory.

    RF100 (c) 1998 Scott Baxter

  • Bibliography (concluded)Wireless and Personal Communications Systems by Garg, Smolik & Wilkes. 445 pp., Prentice Hall, 1996, $68. ISBN 0-13-234-626-5 $68. This is the little brother of The Mobile Communications Handbook. Good explanation of each technology for a technical newcomer to wireless, but without quite as much authoritative math or deep theoretical insights. Still contains solid theory and discussion of practical network architecture.

    "Voice and Data Communications Handbook" by Bates and Gregory 699 pp, 360 illus., McGraw-Hill # 05147-X, $65 Good authoritative reference on Wireless, Microwave, ATM, Sonet, ISDN, Video, Fax, LAN/WAN

    "Communication Electronics" by Louis E. Frenzel, 2nd. Ed., list price $54.95. Glencoe/MacMillan McGraw Hill, April, 1994, 428 pages hardcover, ISBN 0028018427. All the basic principles of transmission and their underlying math. If you didnt take signals & systems in school, this is your coach in the closet.

    Digital Communications: Fundamentals and Applications by Bernard Sklar. 771 pp., Prentice Hall, 1988. $74 ISBN# 0-13-211939-0 Excellent in depth treatment of modulation schemes, digital processing theory, noise.

    "Wireless Personal Communications Services" by Rajan Kuruppillai. 424 pp., 75 illus., McGraw-Hill # 036077-4, $55 Introduction to major PCS technical standards, system/RF design principles and process, good technical reference

    "PCS Network Deployment" by John Tsakalakis. 350 pp, 70 illus., McGraw-Hill #0065342-9, $65 Tops-down view of the startup process in a PCS network. Includes good traffic section.

    "The ARRL Handbook for Radio Amateurs (1997)" published by the American Radio Relay League (phone 800-594-0200). 1100+ page softcopy ($44); useful exposure to nuts-and-bolts practical ideas for the RF-unfamiliar. Solid treatment of the practical side of theoretical principles such as Ohms law, receiver and transmitter architecture and performance, basic antennas and transmission lines, and modern circuit devices. Covers applicable technologies from HF to high microwaves. If you havent had much hands-on experience with real RF hardware, or havent had a chance to see how the theory you learned in school fits with modern-day communications equipment, this is valuable exposure to real-world issues. Even includes some spread-spectrum information in case youre inclined to play and experiment at home. At the very least, this book will make dealing with hardware more comfortable. At best, it may motivate you to dig deeper into theory as you explore why things behave as they do.

    RF100 (c) 1998 Scott Baxter

  • End of Section

    RF100 (c) 1998 Scott Baxter

  • How a BTS Builds the Forward Code Channels

    RF100 (c) 1998 Scott Baxter


Recommended