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Workshop 1 WCDMA Overview 16/09/2008 Confidential
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Workshop 1WCDMA Overview
16/09/2008
Confidential
CONFIDENTIAL
Workshop Contents [WCDMA Overview]WCDMA/UMTS Network Architecture
Core Network Element OverviewMSC, SGSN, GGSN, Iu Interfaces
UTRAN Network Element and Feature OverviewRNC, Node-B
Radio Access Bearer
Introduction to Air-Interface
UMTS-FDD Carriers
Spreading & Processing Gain
Spreading Factor vs. Transmit Power
WCDMA Transmitter- Coding, Interleaving, Spreading
- DL & UL Channelization Codes
- Scrambling Codes
- Modulation, Rake receiver
UMTS Protocol Overview
Channel Organization/Mapping in UMTS
DL Common Control Channel Power Settings
Day 1
Day 2
CONFIDENTIAL
WCDMA/UMTS System Objectives
Providing broad range of servicesvoice, video, data with variable rates, and especially multimedia services.
High quality of service with complete security and reliability
Easy and smoothly transition from 2G to 3G, backwards compatibility with 2G
High spectral efficiency
Capable of roaming globally
CONFIDENTIAL
WCDMA/UMTS Applications/Functions
CONFIDENTIAL
WCDMA/UMTS Network Architecture
CONFIDENTIAL
CORE NETWORK ELEMENT OVERVIEW
The CN is responsible for switching and routing calls and data connections to external networks.
It contains the physical entities that provide support for the network features and telecommunications services.
It is also responsible for providing the mobility and location services on the highest level of the UE.
The CN handles both packet-oriented services (such as data) and circuit-oriented services (such as speech).
The UMTS CN can be organised into two main domains:
CS Domain
PS Domain
CONFIDENTIAL
CORE NETWORK ELEMENT OVERVIEW (II)
CS domainThis domain offers circuit switched bearer services. The cs domain is mainly used for real time data services, including speech and video transmission.
The network entities MSC, GMSC and VLR can be found here.
PS domainThis domain offers packet switched bearer services. It is based on the GSM feature GPRS.
Originally, this domain was developed for non-real time packet switched applications, such as file transfer, email, access to the Internet. But there are tendencies to improve its offered QoS, so that real time services can be offered, too. The SGSN and GGSN are located in the packet switched domain.
There are also some network elements, which are shared by the packet switched and circuit switched domain.
The common network elements comprise the HLR, AuC and EIR.
A set of network elements were specified for application provisioning, which can be also found in the CN.
Examples are the Camel Service Environment and WAP.
CONFIDENTIAL
WCDMA/UMTS Core Network Architecture and Interfaces
CIRCUIT SWTICHED CORE
PSTN/Legacy/External
PACKET SWTICHED CORE
SGSN GGSNMultimedia IP
NetworksGn Gi
MGW
MSC GMSC
HLREIR
DF
AuCC
H
GcGrGf
Gs
RNS
TE MT Node B RNCUu Iub
Iur
TE MT Node B RNCUu Iub
R
R
Iu-ps
Iu-cs
MGWIu-cs
Iu-ps
CONFIDENTIAL
MSC SERVER FUNCTIONALITY: Services
Services Supported by the MSCTeleservices
- Telephony, Emergency calls, Originating & Terminating, SMS
Bearer Services- The MSC server supports circuit based data up to 64 kbit/s. It is also possible to
use lower bit rates.Supplementary Services
- Examples include: Line Identification, Call Forwarding, Call Waiting and Call Hold, Multi Party, Closed User, Group, Advice of Charge, Call Barring, Call completion to Busy Subscriber, EMLPP (Enhanced Multi-level Precedence and Preemption).
Unstructured Supplementary Service Data (USSD), as specified in 3GPP
IN in CAMEL- Customized Applications for Mobile Network Enhanced Logic.- The main application of CAMEL is the support of prepaid charging, also referred
to as real-time or on-line charging.
Positioning Service- This service indicates the position of the mobile. Positioning is based on the
transfer of geographical coordinates stored in the MSC Server that uses the MAP and CAP protocols. A translation is performed internally between the position of the cell and the geographical coordinates.
CONFIDENTIAL
MSC SERVER FUNCTIONALITY:Control Functions
Connection management
The MSC Server handles circuit-based connection management. Iu control signaling is performed between the MSC Server and UTRAN, while the user plane is set up via media gateways without passing the MSC Server.
In the event that tones, announcements, connection of transcoders, etc., are required, the MSC Server orders the devices to be connected.
Mobility management
Roaming: The MSC Server supports mobility management in order to enable attachment/detachment and roaming within the UMTS network, between UMTS networks, and between UMTS and GSM networks.
Handover: The MSC Server supports intra-MSC SRNS relocation, inter-MSC and intra-MSC handover from UMTS to GSM
Security
Subscriber authentication, Key agreement, Ciphering, Data integrity, Negotiation of algorithm
Charging
CONFIDENTIAL
MSC SERVER FUNCTIONALITY:Media Streaming
Coding/decoding
The Transcoder Unit will provide coding/decoding between UTRAN and the UMTS circuit-based Core Network and between UTRAN and the external network.
Echo cancellation
Echo cancellers are provided to attenuate echo generated at the conversion between the 4-wire and 2-wire transmissions in the PSTN and acoustic echo generated in the user equipment.
Tone handling
Devices are provided to send and receive DTMF tones as requested by push-button signals originating in the user equipment. Devices are provided for sending tones such as ringing tones and busy tones, to the mobile subscriber.
Conference Calls
The Conference Call Device (CCD) is provided for bridging multiparty calls.
Announcement machine
Announcement Service Terminals (AST) are provided to make announcements to end-users.
CONFIDENTIAL
SGSN Server
The SGSN handles the communication with MSs and the establishment of the connection between an MS and the Packet Data Network.
It forwards IP packets between all GPRS attached MSs within that SGSN service area and the GGSN
SGSN Main Functions
Session management
Mobility management
Subscriber data management
Security
GGSN control signaling
Charging
Admission Control
MAP and RANAP control signaling
SMS
CONFIDENTIAL
SGSN SERVER FUNCTIONALITY: Description (1)
Session management:
SGSN functionality for session management is responsible for establishment, maintenance and release of end user PDP contexts.
This includes inter-working with the GGSNs for IP address allocation if dynamic IP addresses are used.
Session management also includes functionality for establishment and release of WCDMA Radio Access Bearers (RAB) for end user IP data transportation.
Mobility management:
Functionality supports intersystem handover within and roaming between mobile networks
Subscriber data management:
SGSN supports the standardized interface to the HLR for management of end user subscriber data such as International Mobile Subscriber Identity (IMSI), Access Point
Names, Subscribed QoS etc.
Security:
It includes subscriber authentication for attach/detach and location update procedures.
CONFIDENTIAL
SGSN SERVER FUNCTIONALITY: Description (2)
GGSN control signaling:
The GTP-C protocol for control signaling between SGSN and GGSN is supported. GTP-C is transported by UDP/IP and contains functionality for SGSN - GGSN tunnel management and control.
Charging:
SGSN supports off-line charging with generation of CDRs, and on-line charging according to CAMEL prepaid is supported.
Admission Control:
function is handling the control of the following:
maximum number of simultaneously attached users in the SGSN
maximum bit-rate in the SGSN
The Admission Control function also includes a control of the MS requested QoS profile against the subscribed QoS profile.
MAP and RANAP control signaling:
SGSN supports the RANAP protocol for control signaling over the RNC-SGSN interface for establishment and release of Radio Access Bearers.
SMS:
SGSN treats SMS messages as control traffic, SMS messages can be sent as soon as a control connection has been established and no dedicated RAB is required
CONFIDENTIAL
SGSN SERVER Interfaces
CONFIDENTIAL
GGSN Server
GGSN is effectively the gateway to external data networks.
It forwards uplink and downlink IP packets between the SGSN and the PDN
The GGSN handles session management, that is, activation, modification, and deactivation of PDP contexts for sessions between the GGSN and the SGSN, and between the GGSN and the PDN.
Session management also includes dynamic IP address allocation and QoS negotiation.
Supports control signaling towards external IP networks for authentication and IP address allocation,
Supports mobility within the mobile network. It communicates with one or several SGSNs.
The GGSN provides functions for forwarding and handling user information (IP packets) to and from external networks (Internet/intranets).
CONFIDENTIAL
GGSN FUNCTIONALITY
The main functions of the GGSN are as follows:Session and Mobility management
- The GGSN handles establishment, maintenance and release of PDP contexts that are initiated on request by an SGSN.
- The GGSN includes functionality for intra-PLMN and inter-PLMN routing of IP packets.
IP address allocation
- The GGSN is responsible for allocation of dynamic IP addresses.
- The GGSN can either allocate the IP addresses itself, or interact with a RADIUS server for end user authentication and retrieval of IP addresses.
- Dynamic address allocation enables the use of IP addresses from a common pool of addresses.
CONFIDENTIAL
Core Interfaces
CONFIDENTIAL
Iuc/ps Function Key Functions
Iucs and Iups provide the control relationships between each of the RNCs and the CS servers (MSC) and PS servers (SGSN)
For IuCS, an RNC can only be controlled by one MSC.
- One MSC can control several RNCs.
For IuPS, an RNC can only be controlled by one SGSN.
- One SGSN can control several RNCs.
The Iu interface, normally uses two parallel STM-1 links connecting the
RNC to the RNSGW in the Core Network. The two links are configured as a redundant pair to protect against both equipment and transmission link faults.
A core network may use the Media Gateway (M-MGw) to perform the role specified for the RNSGW
CONFIDENTIAL
UTRANUMTS Terrestrial Radio Access Network
Overview
CONFIDENTIAL
UTRAN architecture
Hierarchical Architecture
UTRAN Elements:
- Radio Network Controller
- Node B (Base Station)
UTRAN consists of a set of Radio Network Subsystems (RNS) connected to CN through Iu
Node B connects to RNC through Iub
Iur interface between RNC for soft handover
CONFIDENTIAL
RNC roles
Concerning one connection between UTRAN and one UE, the following roles of RNC exists:
Serving RNC (SRNC) that control the connections to a UE
Drift RNC (DRNC) that lends its resources for the Serving RNC for a particular UE
Each RNC also has the controlling role towards its Node Bs (CRNC).
One UE connected to UTRAN has one and only one SRNC
One UE may have zero, one or more DRNCs
CONFIDENTIAL
Iur Key Functions
Iur is the Interface connecting 2 RNCs
Supports Inter-RNC Mobility, Soft HandoversDedicated channel traffic, (user data transfer with dedicated connection)
- Allow anchoring of SRNC when UE is in Dedicated channel (DCH) state
Common channel traffic- Allow anchoring of SRNC and also when UE is in common channel
(RACH/FACH) state
Flow control between SRNC and DRNC
• Transfer of positioning parameters between controller
• Transfer of Node B timing information between two RNCs
Anchoring
Iur
Huawei also supports RNC relocation. When UE leaves SHO DRNC becomes SRNC
It establishes a new Iu interface and the Iur is terminated.
CONFIDENTIAL
RNC Key Functions
Responsible for processing of user data
Responsible for Radio Resource Management
Comparable to Base Station Controller in GSM
Key RNC Functions:
Closed loop power control
Handover control
Capacity Management (Admission & Congestion Control)
Code allocation
Packet scheduling
Macro diversity combining/splitting over number of Node Bs
CONFIDENTIAL
Node-B Key Functions
Comparable to Base Transceiver Station in GSM
Responsible for Air Interface Layer 1
Key Node B Functions:
Inner-loop power control
Modulation and spreading
RF Processing
Rate matching
Micro diversity combining/splitting inside Node B
CONFIDENTIAL
RNC & Node-B Feature OverviewPower Ctrl, Handover Ctrl, Capacity Management
CONFIDENTIAL
Power Control
Power control is the most important element in DS-CDMA in particular on the uplink.
Because many users access and use the same frequency and bandwidth at the same time, there is a high possibility of interference between the users.
In the case where there is no power control, it may happen that an MS at the cell edge suffers from a higher path loss than another MS that is close to the RBS. If there were no mechanism for the MSs to be power controlled to the same level at the base station, the MS that is closer to the base station could easily over shout the other MS and block a large part of the cell giving rise to the so-called ‘near-far problem’.
In order to maintain good capacity levels in the network, the signals received by the RBS, no matter where the MSs are transmitting from (that is near or far) should be of equal power assuming that all MSs are transmitting at the same user bit rate.
CONFIDENTIAL
Three types of power control
1. Open-Loop (slow) power control
2. Inner-Loop (fast) power control and
3. Outer-Loop power control
CONFIDENTIAL
Power Control Flow Chart
CONFIDENTIAL
Uplink Signal to Interference Ratio (SIR)
SIR is defined (according to 3GPP) = (RSCP/ISCP)*SFWhere:
RSCP = Received Signal Code Power
SF = The spreading factor of the DPCCH
ISCP = Interference Signal Code Power
- ISCP is normally approximated by the RTWP (Received Total Wideband Power)
SIR = (RSCP/RTWP)*SF
Since these terms are normally expressed in dB:
SIR = RSCP – RTWP + 10logSF
To solve for RSCP:
RSCP = RTWP + SIR - 10logSF
CONFIDENTIAL
Downlink Signal to Interference Ratio (SIR)
In the downlink transmitter the bits are passed though a 1:2 de-mux
SIR = (RSCP/ISCP)*SF/2Where:
RSCP = Received Signal Code Power
SF = The spreading factor of the DPCCH
ISCP = Interference Signal Code Power
- ISCP is normally approximated by the RTWP (Received Total Wideband Power)
SIR = (RSCP/RTWP)*SF/2
Since these terms are normally expressed in dB:
SIR = RSCP – RTWP + 10log(SF/2)
To solve for RSCP:
RSCP = RTWP + SIR - 10log2/SF
CONFIDENTIAL
Handover Introduction
The purpose of handover is to maintain the connection quality while utilizing as little radio resources as possible while the UE moves between cells.
In a Wideband Code Division Multiple Access Radio Access Network (WCDMA RAN) system, there are several types of handover:
Soft/Softer Handover- When the UE is in connected mode, CELL_DCH state. It permits
"neighboring" cells to use the same frequency and the UE to have mobility in order to keep the connection without interruption.
Inter-Frequency Handover:- When the UE in connected mode, CELL_DCH state, is moving out of
coverage of one WCDMA RAN frequency and into coverage of another WCDMA RAN frequency. It will cause some interruptions to the connection (Hard HO)
Inter-Radio Access Technology (Inter-RAT) Handover- When the UE in connected mode, CELL_DCH state, is moving out from
WCDMA RAN coverage into an area where only GSM/GPRS coverage exist. It will cause some interruptions to the connection (Hard HO)
CONFIDENTIAL
Handover Introduction (entities involved during the reporting, evaluation, and execution phases)
SHO_Eval: Soft/Softer Handover evaluation algorithm. IFHO_Eval: Inter-Frequency Handover evaluation algorithm. IRATHO_Eval: Inter-RAT Handover (WCDMA RAN to GSM/GPRS) evaluation algorithm. SBHO_Eval: Service Based Handover (WCDMA RAN to GSM for speech users only) evaluation algorithm, as a particular case of IRATHO algorithm. IRATCC_Eval: Inter-RAT Cell Change (WCDMA RAN to GSM/GPRS) evaluation algorithm. CNHHO_Eval: Hard Handover via Core Network evaluation algorithm. HSCC_Eval: HS-DSCH Cell Change evaluation algorithm. Meas_Handl: Measurement handling algorithm. UE_Meas_Eval: UE measurement evaluation algorithm (working in the UE)..
Entities Involved in Reporting, Evaluation, and Execution of Handover-Related Functions.
CONFIDENTIAL
Soft/Softer Handover Basics (1)In Soft Handover, the UE connection consists of at least two radio links established with cells belonging to different Radio Base Stations (RBS).
In Softer handover, the UE connection consists of at least two radio links established with cells belonging to the same RBS.
A combination of Soft and Softer Handover is also possible for a UE connection
Data flow is not interrupted during the addition or removal of radio links.
The downlink signals, received by the UE, are combined in the RAKE receiver; that allows for multipath reception and thereby gives protection against fading
CONFIDENTIAL
Capacity Management Overview
WCDMA RAN Capacity Management solution controls the load in the WCDMA cell.
This makes it possible for the system to provide the requested QoS and coverage for individual connections.
Each cell or group of cells has its own set of Capacity Management functions responsible for monitoring and controlling the resources of that cell.
The Capacity Management solution consists of three main functions:
Dedicated Monitored Resource Handling
Admission Control
Congestion Control
CONFIDENTIAL
Capacity Management Overview
CONFIDENTIAL
Capacity Management Functions Overview (1)
Dedicated Monitored Resource Handling
The Dedicated Monitored Resource Handling function is responsible for keeping track of the utilization of critical resources in the system.
The utilization of these resources provides information that is used by Admission and Congestion Control functions to control the cell load.
- It provides information about the current usage of resources that are critical to the load of the cell.
This is done by performing measurements and keeping track of every radio link setup, addition, deletion, and modification in the cell.
CONFIDENTIAL
Capacity Management Functions Overview (2)
Admission ControlThe Admission Control function is responsible for controlling the utilization of dedicated monitored resources by accepting or refusing requests for usage of these resources.
Those requests are initiated when setting up new connections, performing (soft) handover, and reconfiguring existing connections.
The decision on accepting or refusing a request takes into account the current load on the dedicated monitored resources and the characteristics of the request.
Congestion Control The Congestion Control function is responsible for detecting and resolving overload situations on certain dedicated monitored resources.
These overload situations can, for example, occur due to fluctuations in the radio conditions for the individual users.
Overload is resolved by a combination of blocking additional admission requests in a cell and issuing congestion resolve actions towards individual users
- for example: switching packet users to lower rates, and releasing connections
CONFIDENTIAL
What is the Bearer?
The user traffic, known as the user plane, is carried through the network from the mobile to the core network on a bearer.
In GSM, the traffic channel was the bearer.
In UMTS, a bearer is a varied bit rate and is allocated depending on the needs of the subscriber.
The actual data in the bearer is transparent to the network.
CONFIDENTIAL
Bearer CharacteristicsD O C U M E N T T Y P E 1 ( 1 )
M o b i l e P h o n e sT y p e Y o u r N a m e H e r e T y p e D a t e H e r e
C o n v e r s a t i o n a l c l a s s V o i c e a n d v i d e o
S t r e a m i n g c l a s s S t r e a m i n g v i d e o
I n t e r a c t i v e c l a s s W e b b r o w s i n g
B a c k g r o u n d c l a s s M a i l d o w n l o a d i n g
CONFIDENTIAL
Types of bearer
A bearer has different parameters, such as variable data rates, protection and delay.
The bearer is dependent on the service required.
VoiceVoice Messages
MessagingTransactionalInfoservices
WWW browsingIntranet accessDownloading
Audio/Video Streaming
0 8 16 32 48 64 80 96 112 128 256 384 kbit/s
Video telephony
CONFIDENTIAL
Relationship between the RAB and Signaling Protocols
As the bearer is passing through the network elements, we need to control its activities.
One network element must be capable of sending and receiving messages to other network elements (Node B to RNC, RNC to CN and RNC to RNC).
This is called signaling.
Standardized signaling protocols specify how two pieces of equipment can communicate and understand messages.
The figure below illustrates the user plane information between the terminal and the core network through the network by use of the RAB.
CONFIDENTIAL
UMTS Planes
Transport plane protocols:
Transport plane provides the means how the physical connection is established between the User Equipment (UE) and the network.
Provides a reliable connection between two end nodes. Is responsible for the transport of higher layer data
User plane protocols:
Protocols implementing the radio access bearer service carrying user data through the access stratum (parallel layers).
Control plane protocols:
Protocols for controlling the radio bearers and the connection between the User Equipment (UE) and the network from different aspects (including requesting the service, controlling different transmission resources, handover, and so on).
CONFIDENTIAL
Transport Plane Iu-PS, Iu-CS, Iur, & Iub:
Physical Layer
ATM
AAL2
Service:• Variable bit rate• Source & destination
synchronised• connection orientated
AAL5
Service:• Variable bit rate• Source & destination
not synchronised• connection orientated
control data
Iu-CS, Iu-PS, Iur, Iub
user dataIu-PS
user data
Iu-CS, Iur, Iub
CONFIDENTIAL
RAN interfaces & Functions Summary
BS Functions: - Modulation - Rate Matching - Error Protection in Uu Interface - Uu Interface Channelisation - Macro Diversity (Softer Handover)
Uu Interface:Transport Plane
Control Plane
User Plane
Procedures
- WCDMA (Wideband Code Division Multiple Access) - DPDCH and DPCCH Channels - Optimised, application-related protocols suitable for both packet and circuit switched traffic - Radio Link (RL) Setup - RL Reconfiguration - RL Addition - RL Deletion - Radio Access Bearer Mgmt
Iub Interface:Transport Plane
Control Plane
User Plane
Procedures
- ATM - Communication Control Ports - Node B Control Ports - RACH/FACH/DCH Data Ports forming UE Context(s) - Radio Link (RL) Setup - RL Reconfiguration - RL Addition - RL Deletion - Power Control Information - Handover Signalling - Measurement Reports
Iur Interface:Transport Plane
Control Plane
User Plane
Procedures
- ATM - SCCP over CCS7 - Frame Protocols for Dedicated Channels over ATM - Radio Link (RL) Setup - RL Reconfiguration - RL Addition - RL Deletion - Power Control Information - Handover Signalling - Measurement Reports
Iu Interface for CN Packet Domain: Transport Plane
Control Plane
User Plane
Procedures
- ATM - RANAP over CCS7 or IP - GTP (GPRS Tunnelling Protocol) over UDP/IP over AAL5 - Radio Access Bearer Management - SRNC Relocation - Direct Transfer Procedures (Direct Signalling between UE and the CN Packet Domain)
Iu Interface for CN Circuit Domain: Transport Plane
Control Plane
User Plane
Procedures
- ATM - RANAP over CCS7
- Optimised, application-related protocols over ATM AAL2
- Radio Access Bearer Management - SRNC Relocation - Direct Transfer Procedures (Direct Signalling between UE and the CN Circuit Domain)
4
BS
BS RNC
RNC
RNC Functions: Radio Resource Management
Telecommunication Management
- Admission Control - Code Allocation - Load Control - Power Control - Handover Control (HO) - Macro Diversity (Soft HO) - Radio Access Bearer (RAB) - RAB - Radio Link Mapping
CONFIDENTIAL
UTRAN OverviewIntroduction to Air-Interface
CONFIDENTIAL
UTRAN Interfaces UTRAN DefinitionsRNS (Radio Network
Subsystem)A full or partial network offering access between UE and Core NetworkContains one RNC
RNC (Radio Network Controller)
Element of the RNS that controls physical radio resources
Node BLogical Node controlling transmission and reception from one or more cells
Iub InterfaceInterface between RNC and Node B
Uu InterfaceInterface between UE and Node B
Iur InterfaceInterface between one RNS and another RNS
Iu InterfaceInterface between CN and RNS
CONFIDENTIAL
WCDMA Direct Sequence CDMA (DS-CDMA)
WCDMA/UMTS uses Direct Sequence CDMA (DS-CDMA), the information for each user is spread with a unique code.
Separate Users through different Codes
Provides large bandwidth
Provides continuous transmission and reception
CDMA is also known as a Spread Spectrum Technology.
CONFIDENTIAL
UMTS-FDD Carriers
DiGi Carriers
Ch. Number (UARFCN UL/DL = Carrier Center Freq * 5 = 2112.4*5 =10562
Others Operator CarriersCarrier 1 Carrier 2 Carrier 3
Uplink 1920 1925 1930Downlink 2110 2115 2120
Uplink 9612 9637 9662Downlink 10562 10587 10612
Uplink 1935 1940 1945Downlink 2125 2130 2135
Uplink 9687 9712 9737Downlink 10637 10662 10687
Uplink 1950 1955 1960Downlink 2140 2145 2150
Uplink 9762 9787 9812Downlink 10712 10737 10762
U Mobile
Maxis
CelcomMHz
Ch. Number
MHz
Ch. Number
MHz
Ch. Number
Carrier 1 Carrier 2 Carrier 3Uplink 1965 1970 1975
Downlink 2155 2160 2165Uplink 9837 9862 9887
Downlink 10787 10812 10837
DiGiMHz
Ch. Number
CONFIDENTIAL
WCDMA terminology – Bits, Symbols, & Chips
Terms: Bit, Symbol, Chip Bit : data after source coding
Symbol: data after channel coding and interleaving
Chip: data after spreading
Processing Procedure of WCDMA System
CONFIDENTIAL
SPREADING WITH CODES
The process of spreading
A bit of information is a ‘1’ or a ‘0’ (digital) or a ‘-1’, ‘+1’ (analogue).
The user information bits are spread into a number of chips when it is “multiplied” with the spreading code (which is unique).
- The chip rate for the system is constant 3.84 Mchip/s
- and the signal is spread into a bandwidth of 5 MHz.
The Spreading Factor (SF) is the ratio between the chip rate and the symbol rate.
- This is equal to the spreading gain (i.e. the protection against interference).
The same code is used to dispread the information after it is sent over the air interface, i.e. both the UE and the RBS use the same codes.
Different bit rates and Spreading Factors at a constant chip rate
CONFIDENTIAL
Spreading Factor & Processing Gain
FrequencyPow
er
den
sity
(W
att
s/H
z)
Unspread narrowband signal Spread wideband signal
Bandwidth W (3.84 Mchip/sec)
Bit rate R
sec84.3 MchipWconstSFR
SFR
W
B
BdBG
Baerer
Up
u Gp: processing gainBUu: system chip rateBBearer: bearer symbol rateSF: spreading factor
CONFIDENTIAL
Processing Gain Examples
Voice user (R=12,2 kbit/s)
Packet data user (R=384 kbit/s)
Pow
er
den
sity
(W
/Hz)
R
Frequency (Hz)
Gp=W/R=24.98 dB
Pow
er
den
sity
(W
/Hz)
R
Gp=W/R=10 dB
• Spreading sequences have a different length• Processing gain depends on the user data rate
=10log10 (3.84^6/12.2^3)
CONFIDENTIAL
Transmission Power
To send a stream of bits, a certain power is needed.
The bit rate has a constant relationship to the power level and if the bit rate is high, then the power level becomes high and vice versa
Frequency
5MHz
Power
Time
High bit rate user
Low bit rate user
CONFIDENTIAL
Spreading Factor vs. Power
Since the chip rate is constant, the spreading factor is low when the bit rate is high.
One of the most important characteristics of WCDMA is the fact that power is the common shared resource.
Imagine like a box with fix volume
• When SF Increases Power decreases
• When SF decreases Power increases
CONFIDENTIAL
Eb/No and Processing Gain
Eb/N0 (the energy per bit to noise power spectral density ratio) is an important parameter in digital communication or data transmission
In 3G radio network planning and system dimensioning typically make use of the terms Eb/No and Processing Gain (PG).
defines the required and achieved carrier to interference (C/I) ratio i.e. C/I = Eb/No - PG.
Both Eb/No and PG are relatively conceptual and are not quantities that can be measured directly.
Eb/No is provided by the equipment vendors for the Uplink and Downlink, for the different CS and PS services and for the different channel model types (i.e. TU3, TU50, RA50 etc)
Table below are the Eb/No values used by Huawei
UL DL
AMR12.2 5.4 7.8
CS64 2.8 6.3
PS64 2.6 4.8
PS128 2.3 4.7
PS384 1.8 3.8
Huawei's Required Eb/No (dB)
CONFIDENTIAL
Processing Gain and Eb/No Example
Processing gain is what gives CDMA systems the robustness against self-interference that is necessary in order to reuse the available 5 MHz carrier frequencies over geographically close distances.
Let’s take an example with real WCDMA parameters.
Speech service with a bit rate of 12.2 kbps has a processing gain of 25 dB, 10log10 (3.84e6/12.2e3).
After dispreading, the signal power needs to be typically a few decibels above the interference and noise power.
The required power density over the interference power density after dispreading is designated as Eb/No, where Eb is the energy, or power density, per user bit and No is the interference and noise power density.
For speech service Eb/No is typically in the order of 7.0 dB, and the required wideband signal-to-interference ratio is therefore 7.0 dB minus the processing gain is 18.0 dB.
In other words, the signal power can be 18 dB under the interference or thermal noise power, and the WCDMA receiver can still detect the signal.
Kbps PG12.2 25.064 17.8
128 14.8384 10
Processing Gain
PG=10log(chip/bit rate)
CONFIDENTIAL
WCDMA Transmitter
Pulse Shaping
Filter
Pulse Shaping
FilterRF Out
Data Channel
1
Data Channel
N
Linear
Summation
Linear
Summation
Spread Spectrum Code
(PN Code or Gold Code)FEC
Coding
FEC Coding
Orthogonal Code 1
Orthogonal Code N
1:2Demux
1:2Demux
Pulse Shaping
Filter
Pulse Shaping
Filter
I/Q Modulat
or
I/Q Modulat
or
CRC Coding
CRC Coding Inter-
leaving
Inter-leaving
CRC Coding
CRC Coding
Complex Multipli
er (I + jQ)
Complex Multipli
er (I + jQ)
FEC Coding
FEC Coding Inter-
leaving
Inter-leaving
D/AD/A
D/AD/A
SSC_QSSC_I
I
Q
I
Q
I
Q
Allows for error
detection in the receiver
Allows for error correction in the receiver
Improves error
correction in the
receiver
Gives a unique
identity to each data
stream
Maps digital bits to analog signals
0 +1
1 -1
Provides 2x higher data rate
(WCDMA,cdma2000 downlink)
Gives a unique
identity to this
transmitter
Contains transmitt
ed frequency spectrum
Allows both signals from 1:2 Demux to share
the same RF bandwidth
Pre-coded data (bits)
Symbols Chips
+
+
CRC: Cyclic Redundancy CheckFEC: Forward Error Correction
Add CRC to Transport Block
Channel Coding:Convolutional or TurboStarts here
CONFIDENTIAL
Air interface: Coding, Interleaving, Spreading
The number of chips per data symbol is called the Spreading Factor (SF).
The lower the spreading factor the higher the data rate.
SF value varies in FDD from 4 to 512.
CONFIDENTIAL
WCDMA Channel Coding
During the transmission, there are many interferences and fading.
To guarantee reliable transmission, system should overcome these through the channel coding which includes convolution and interleaving.
Convolution that is used for overcome interference. Through the technology, many redundant bits will be inserted in original information.
When error code is caused by interference, the redundant bits can be used to recover the original information.
3 types of Channel Coding are possible [per code block of N bits]1/2 rate convolutional channel coding [2N + 16 bits], coded information1/3 rate convolutional channel coding [3N + 24 bits]turbo coding [3N + 12 bits]
Convolution code applies to voice service while Turbo code applies to high rate data service.
Channel Coding Increases the delay
CONFIDENTIAL
InterleavingInterleaving ‘spreads out’ consecutive bits in time
Reduces the probability of losing consecutive bits
Convolutional encoding is sensitive to consecutive bit loss
Trades delay time for data protection
Longer interleaving periods have better data protection with more delay
Interleaving periods:10, 20, 40, or 80 ms
Most coding schemes perform better on random data errors than on blocks of errors.
By interleaving the data, no two adjacent bits are transmitted near to each other, and the data errors are randomized.
CONFIDENTIAL
Spreading Codes in WCDMA
In WCDMA, two types of codes are used in tandem for spreading the channel bits into a wideband CDMA chip sequence:
channelization codes, and
scrambling codes.
after spreading the scrambling code only modifies the chip values in the transmitted chip sequence in such a way that the cross-correlation interference in the system is minimised.
the channelization code performs the actual signal spreading to the final chip rate (3.84 Mchips/s)
CONFIDENTIAL
DL & UL Channelization CodesChannelization codes, or Walsh Codes, are often referred to as Orthogonal Variable Spreading Factor (OSVF)
SF for the DL transmission in FDD mode = {4, 8, 16, 32, 64, 128, 256, 512}
SF for the UL transmission in FDD mode = {4, 8, 16, 32, 64, 128, 256} - A lower SF means a higher data rate, because this means less chips per symbol
- PS384 kbps (DL) SF=8 => 8 chips per symbol
- AMR12.2 kbps (DL) SF=128 => 128 chips per symbol
The codes have orthogonal properties to minimize the interference between different users.
Two vectors that are orthogonal give the resulting vector 0, when they are multiplied with each other.
This means that the coded information is only affected by the “right” orthogonal code when it is dispread.
In this way the interference can be minimized.
The channelization codes preserve the orthogonality between the different physical channels of users even if they operate at different bit rates
Orthogonal codes are suited for channel separation, where synchronisation between different channels can be guaranteed, e.g.
downlink channels under one cell,
uplink channels from a single user;
- uplink signals from different users are not time synchronised.
CONFIDENTIAL
Channelization codes
Channelization codes are very important in downlink, since they are used for multiplexing (at the transmitter) and separating (at the receiver) the signals intended for different terminals.
In uplink, channelization codes are used for multiplexing the data and control channel (DPDCH and DPCCH) signals transmitted from a single terminal.
In both directions, the channelization codes are employed for spreading the channel bits to the final chip rate of 3.84 Mchips/s.
The required bit rate - and thus the spreading factor - of some services may change over time. The transmitter takes care of changes in the spreading factor among others by changing the channelization code.
The channelization codes are based on the Orthogonal Variable Spreading Factor (OVSF) technique, which allows the spreading factor to be changed without disrupting the orthogonality between different codes of different lengths simultaneously in use.
CONFIDENTIAL
Channelization Code Tree
C0(0)=[1]
C2(1)=[1-1]
C2(0)=[11]
C4(0)=[1111]
C4(1)=[11-1-1]
C4(2)=[1-11-1]
C4(3)=[1-1-11]
C8(0)=[11111111]
C8(1)=[1111-1-1-1-1]
C8(2)=[11-1-111-1-1]
C8(3)=[11-1-1-1-111]
C8(0)=[1-11-11-11-1]
C8(5)=[1-11-1-11-11]
C8(6)=[1-1-111-1-11]
C8(7)=[1-1-11-111-1]
C16(0)=[............]C16(1)=[............]
C16(15)=[...........]
C16(14)=[...........]
C16(13=[...........]
C16(12)=[...........]
C16(11)=[...........]
C16(10)=[...........]
C16(9)=[............]
C16(8)=[............]
C16(7)=[............]
C16(6)=[............]
C16(5)=[............]
C16(4)=[............]
C16(3)=[............]
C16(2)=[............]
SF=1
SF=2
SF=4
SF=8
SF=16
SF=256
...
CONFIDENTIAL
Tree of Orthogonal Channelization Codes in Downlink
C1(0) = [ 1 ]
C2(0) = [ 1 1 ]
C2(1) = [ 1 0 ]
C4(0) = [ 1 1 1 1 ]
C4(1) = [ 1 1 0 0 ]
C4(2) = [ 1 0 1 0 ]
C4(3) = [ 1 0 0 1 ]
C8(0) = [ 1 1 1 1 1 1 1 1 ]
C8(1) = [ 1 1 1 1 0 0 0 0 ]
. . .
. . .
Spreading factor:
SF = 1 SF = 2 SF = 4 SF = 8
C8(2) = [ 1 1 0 0 1 1 0 0 ]
C8(3) = [ 1 1 0 0 0 0 1 1]
. . .
. . .
C8(4) = [ 1 0 1 0 1 0 1 0 ]
C8(5) = [ 1 0 1 0 0 1 0 1 ]
. . .
. . .
C8(6) = [ 1 0 0 1 1 0 0 1 ]
C8(7) = [ 1 0 0 1 0 1 1 0 ]
. . .
. . .
SF 4
SF 8
SF 16
384 user #1128 user #1
384 user #2
Signaling
The codes have orthogonal properties to minimize the interference between different users.Channelization
codes of different length, depending of the bit rateEnsures
orthogonality even with different rates and spreading factors
Channelization Code Tree
CONFIDENTIAL
DL Primary Scrambling Code
The data stream after the channelization codes, multiplied by a code from a group of special binary codes, to distinguish between different transmitters.
UMTS uses 512 primary scrambling codes, divided into 64 groups of 8
The Common Pilot Channel (CPICH) is an unmodulated code channel, which is scrambled with the cell-specific primary scrambling code.
One DL scrambling code is used per sector in the base station, and it makes the signals from different sources separable from each other.
The DL Scrambling code is used in the cell selection, reselection, and handover process by the UE to distinguish the desired cell.
CONFIDENTIAL
KV Scrambling Code Group Plan
15 Sites per Group
CONFIDENTIAL
Where are codes used?
In the Uplink
(UE Node B),
the user's data and signaling information is
separated by Channelization
Codes
datasignaling
In the Downlink
(Node BUE),
cells are separated by
Scrambling Codes
In the Uplink
(UE Node B),
terminals are separated by
Scrambling Codes
In the Downlink
(Node B UE),
user connections are separated by Channelization
Codes
Dedicated User Channel
CONFIDENTIAL
Channelization and Scrambling Code Summary
Channelization code Scrambling code
Usage Uplink: Separation of physical data and control channels from the same terminal
Downlink: Separation of downlink dedicated user channels
Uplink: Separation of terminals
Downlink: Separation of sectors (cell)
Length Variable (depends on the user allocation)
Fixed
Number of codes
Depends on the spreading factor (SF)
Uplink: Several million
Downlink: 512
CONFIDENTIAL
Air interface - Modulation
QPSK
2 bits / symbol =480 kbit/s/HS-PDSCH =
max. 7.2 Mbit/s
16QAM
4 bits / symbol =960 kbit/s/HS-PDSCH =
max. 14.4 Mbit/s
1011
1001
1000
1010
0001
0011
0010
0000
0100
0110
0111
0101
1110
1100
1101
1111
Q
I
10 00
0111
Q
I
• RF communication systems use advanced forms of modulation to increase the amount of data that can be transmitted in a given amount of frequency spectrum
QPSK uses four phases
They are positioned on a circle so that they can all be transmitted with the same energy This gives maximum phase-separation between adjacent points and thus the best immunity to corruption Can encode two bits per symbol to minimize the BER
The higher order modulations need a much better SNR because when an error occurs on one symbol, more bits are lost.
Example: EDGE (Enhanced Data rates for GSM Evolution) uses an 8-PSK modulation scheme. It can provide data rates up to 380 kbps, but only for users close to the base station (in a 100 m radius approximately),
In UMTS, a spread spectrum modulation is used. It is made of two stages:Symbol modulation based on spread spectrum symbols. Each symbol is modulated by several chips,
Chip modulation based on a simple narrow band modulation. This is a classical PSK modulation.
CONFIDENTIAL
Rake Receiver
CDMA uses the multipath signals and combines them to make an even stronger signal at the receivers due to its wide bandwidth and Rake receivers
It is essentially a set of four or more receivers
One of the receivers (fingers) constantly searches for different multipath and helps the other 3 fingers to lock into strong multipath signals which have more than one chip delay
Each finger then demodulates the signal corresponding to a strong multipath and then the results are combined together to make a stronger signal
CONFIDENTIALMicro/Macro Diversity Combining
Micro Diversity Pointsmax ratio combining is used
Summed signalNode B RAKE
Receiver
MS RAKE
Receiver
Node B
Node B
Node B
S-RNC
D-RNC
Core Network
Active cell set
Macro Diversity Pointselection combining is used
CONFIDENTIAL
UMTS Channel Mapping
CONFIDENTIAL
UMTS Channel Terminology
Downlink – Transmitted by UTRAN, received by UE.
Uplink – Transmitted by UE, received by UTRAN.
Common – Carries information to/from multiple UEs.
Dedicated – Carries information to/from a single UE.
Logical – Defined by what type of information is transferred, e.g., signaling or user data.
Transport – Defined by how data is transferred over the air interface, e.g., multiplexing of Logical Channels.
Physical – Defined by physical mappings and attributes used to transfer data over the air interface, e.g., spreading rate.
CONFIDENTIAL
Radio Interface Protocol Architecture (in UE)
Radio Resource Control (RRC)
Packet Data Convergence Protocol (PDCP)
Broadcast/Multicast Control (BMC)
Radio Link Control (RLC)
Medium Access Control (MAC)
Layer 1 or Physical Layer (PHY or L1)
Radio Bearers – Carry signaling between RRC and RLC or carry user data from application layers to Layer 2.
Logical Channels – Carry signaling and user data between RLC and MAC.
Transport Channels – Carry signaling and user data between MAC and PHY.
Physical Channels – Carry signaling and user data over the radio link.
CONFIDENTIAL
UMTS Channel Organization
UENode B
RNC
Logical channels
Transport channels
Physical channels
Frames
In UMTS there are three different types of channels
CONFIDENTIAL
Radio Interface Channel Description
: Logical ChannelsLogical Channels were created to transmit a specific content. There are for instance logical channel to transmit the cell system information, paging information, or user data.Logical channels are offered as data transfer service by the Medium Access Control (MAC) layer to the next higher layer. Consequently, logical channels are in use between the mobile phone and the RNC. Transport Channels (TrCH)The MAC layer is using the transport service of the lower, Physical layer. The MAC layer is responsible to organise the logical channel data on transport channels. This process is called mapping. In this context, the MAC layer is also responsible to determine the used transport format. The transport of logical channel data takes place between the UE and the RNC. Physical Channels (PhyCH)The physical layer offers the transport of data to the higher layer. The characteristics of the physical transport have to be described. When we transmit information between the RNC and the UE, the physical medium is changing.Between the RNC and the Node B, where we talk about the interface Iub, the transport of information is physically organised in so-called Frames.Between the Node B and the UE, where we find the WCDMA radio interface Uu, the physical transmission is described by physical channels. A physical channel is defined by the UARFCN and the a spreading code in the FDD mode.
CONFIDENTIAL
Downlink channel mapping
SCH-1/SCH-2 (created in NodeB)
BCCH
BCH
PCCH
PCH
CCPCH-1
CCCH
FACH
CCPCH-2
DCCH
(DPDCH+DPCCH)
DTCH Logical Channels
Transport Channels
Physical ChannelsDPCH
CTCH
DCH DSCH
PDSCHSCH-1/SCH-2 (created in NodeB)
BCCH
BCH
PCCH
PCH
CCPCH-1
CCCH
FACH
CCPCH-2
DCCH
(DPDCH+DPCCH)
DTCH Logical Channels
Transport Channels
Physical ChannelsDPCHDPCH
CTCH
DCH DSCH
PDSCH
Logical Channels:Control Channels (CCH):
Broadcast Control Channel (BCCH)Paging Control Channel (PCCH)Common Control Channel (CCCH)Dedicated Control Channel (DCCH)
Traffic Channels (TCH): Dedicated Traffic Channel
(DTCH)Common Traffic Channel
(CTCH)
Transport Channels: Common Transport Channels:
Broadcast Channel (BCH)Paging Channel (PCH)
Forward Access Channel (FACH)Downlink Shared Channel (DSCH)Random Access Channel (RACH)
Common Packet Channel (CPCH)Dedicated Transport Channels:
Dedicated Channel (DCH)
Physical Chs: characterised by
UARFCN,scrambling code,channelization code (optional),start and stop time, andrelative phase
CONFIDENTIAL
Uplink channel mapping
CCCH
PRACH
RACH
DTCH
DPDCH
DCH
DCCH
DPCCH PCPCH
CPCH
Logical Channels
Transport Channels
Physical Channels
Logical Channels:Control Channels (CCH):
Common Control Channel (CCCH)
Dedicated Control Channel (DCCH)
Traffic Channels (TCH): Dedicated Traffic Channel
(DTCH)
Transport Channels: Common Transport Channels:
Random Access Channel (RACH)Common Packet Channel
(CPCH)Dedicated Transport Channels:
Dedicated Channel (DCH)
Physical Chs: characterised by
UARFCN,scrambling code,channelization code (optional),start and stop time, andrelative phase
CONFIDENTIAL
Broadcast Channel
Broadcast Channel (Downlink)
Broadcast Control Channel (BCCH) [Logical/L3]
Broadcast Channel (BCH) [Transport/L2]
Primary Common Control Physical Channel (PCCPCH) [L1]
First channel to be decoded by UE after acquisition
Carries system information such as system ID, cell ID, neighbor cell information, system frame number, etc.
The BCCH Logical Channel carries system information messages necessary for the UE to camp on a WCDMA cell and to access the system.
UTRAN broadcasts this channel continuously, repeating the system information messages at a system configurable repetition rate.
The UE typically reads this channel after power-up or when camping on a new cell and periodically thereafter to ensure that the UE has current system information.
CONFIDENTIAL
Paging Channel
Paging Channel (Downlink)
Paging Control Channel (PCCH)
Paging Channel (PCH)
Secondary Common Control Physical Channel (SCCPCH)
Page Indicator Channel (PICH)
Monitored by UE in Idle Mode, CELL_PCH, and URA_PCH
Carries Paging messages
The PCCH Logical Channel carries paging messages to notify the UE of incoming calls. It is used in conjunction with the physical Page Indicator Channel (PICH).
UTRAN broadcasts the PCH continuously, but the UE typically only monitors the PICH during assigned slots
CONFIDENTIAL
Random and Forward Access ChannelsRandom Access Channel (Uplink)
Common Control Channel (CCCH) [Logical/L3]
Random Access Channel (RACH) [Transport/L2]
Physical Random Access Channel (PRACH)
Transmitted by UE to access the system
Forward Access Channel (Downlink)
Common Control Channel (CCCH)
Forward Access Channel (FACH)
Secondary Common Control Physical Channel (SCCPCH)
Acquisition Indication Channel (AICH)
Carries UTRAN messages to UE in Idle mode
These Uplink and Downlink Channels are used by the UE and UTRAN to communicate when the UE does not have a Dedicated Channel allocated to it.
The RACH has an access protocol associated with it, in which the UE transmits a preamble at increasing power levels until the UTRAN responds on the AICH.
When UTRAN receives a message from the UE on RACH, it responds on FACH. The FACH Transport Channel is mapped to an SCCPCH.
CONFIDENTIAL
Dedicated Channels
Dedicated Channels (Uplink/Downlink)Dedicated Control Channel (DCCH)
[Logical/L3]
Dedicated Traffic Channel (DTCH) [Logical/L3]
Dedicated Channel (DCH) [Transport/L2]
Dedicated Physical Data Channel (DPDCH)
Dedicated Physical Control Channel (DPCCH)
Carries signaling and user data
These Uplink and Downlink Channels are used to carry signaling and user data between the UTRAN and an individual UE.
These channels are assigned when a voice call is active or when a packet data call is transferring data.
CONFIDENTIAL
Frame Structure and TimingFrame Timing
Transmission Time Interval (TTI)
- TTI: 10, 20, 40, 80 ms boundaries
10 ms radio frames, 15 slots per frame
38400 chips per frame
Super Frame = 72 Frames = 720ms
Slot Timing2560 chips per slot, 0.67 ms
Symbol TimingSymbol consists of a number of chips
OVSF determines chips/symbol
OVSF ranges from 4 to 512 chips/symbol
(640 to 5 symbols per slot)
- AMR12.2kbps: SF=128 => 128 chips/symbol => 640/128=5 symbols/slot
- PS384kbps: SF=8 => 8 chips/symbol => 640/8=5=80 symbols/slot
At the 3.84 x 10^6 chipping rate => 38,400 chips per 10 ms Frame => 2560 chips per slot.
CONFIDENTIAL
Uplink Frame Structure for DPDCH and DPCCH
UL DPCH is two Physical Channels: the DPDCH and the DPCCH.
UL Dedicated Physical Data Channel (DPDCH) sent on I branch.
UL Dedicated Physical Control Channel (DPCCH) sent on Q branch.
The control information consists of:
pilot bits to support channel estimation for coherent detection
transmit power-control (TPC) commands,
feedback information (FBI)
optional transport format combination indicator (TFCI)
Each frame of length 10 ms is split into 15 slots,
Each of length Tslot = 0.667 ms, corresponding to one power-control period.
A super frame corresponds to 72 consecutive frames, i.e. the super-frame length is 720 ms.
CONFIDENTIAL
Downlink Frame Structure for DPDCH and DPCCH
There is only one type of downlink dedicated physical channel, the Downlink Dedicated Physical Channel (downlink DPCH).
Within one downlink DPCH, i.e. the dedicated transport channel (DCH), is transmitted in time-multiplex with control information (known pilot bits, TPC commands, and an optional TFCI).
The downlink DPCH can thus be seen as a time multiplex of a downlink DPDCH and a downlink DPCCH.
The control information consists of:
pilot bits to support channel estimation for
coherent detection
transmit power-control (TPC) commands,
feedback information (FBI)
optional transport format combination indicator (TFCI)
CONFIDENTIAL
System Information Messages
CONFIDENTIAL
System Information Messages
The BCCH (Logical Ch) is mapped to the BCH (TrCh).
The Node-B continuously transmits the SIBs in system information messages on the BCH
A UE is always able to find the MIB on the BCCH and to get the scheduling information for the other SIBs
The SIBs contain all information necessary for UEs to work properly in both Idle and Connected mode
UE timers and counters, Cell selection and reselection parameters, Common Physical Channel parameters, Measurement parameters, Neighbor list parameters
Contents MIB SIB1 SIB3 SIB5 SIB7 SIB11 SIB 12PLMN identity XCell selection and reselection parameters X XPaging parameters X XMeasurement management X XCell and common channel configuration XTimers and counters in Idle and Connected mode
X
Power control on common channel XLA and RA updating XSIB Scheduling Information X
CONFIDENTIAL
System Information Structure
The System Information elements are broadcast in System Information Blocks (SIBs).
SIB groups together System Information elements related to the same kind of activity controls.
Different types of SIB exist, and each type contains a specific collection of information.
The SIBs are organized as a tree, as shown below.
A MIB gives reference to a number of SIBs, and its functions include scheduling information for those SIBs.
CONFIDENTIAL
NEMO BCH, MIB, SIB (1)
CONFIDENTIALNEMO BCH, MIB, SIB (2) Cell Selection and Reselection
Parameters
{[-173 (thermal noise density)] – (-58)}
= -115 (qRxLevMin)
CONFIDENTIAL
NEMO BCH, MIB, SIB (3)
CONFIDENTIAL
NEMO BCH, MIB, SIB (4)
Cell & Common Channel Configuration
CONFIDENTIAL
DL Common Control Channel Power Settings
CONFIDENTIAL
DL Common Control Channel Power Settings
Power Settings for the different downlink common channels that are controlled through cell setup and cell reconfiguration.
These include Primary Common Pilot Channel (PCPICH),
Synchronization Channel (SCH)
Primary Common Control Physical Channel (PCCPCH),
DL Common control channels must be heard over the whole cell, thus their power setting is designed for “cell edge”.
DL Common Channels does not have a power control
The power of the common physical channels are set relative to the CPICH:
Power Settings: Actual settings in OSS (Huawei Recommended)
Avr.Pwr (dBm/W): Takes into account the Activity factor
Channel Type Power Settings Activity Factor Max. Pwr(dBm) Avr. Pwr(dBm) Avr. Pwr (W) % of Tot.P-CPICH 0 100% 33.0 33.0 2.0 10.0%P-SCH -5 10% 31.2 21.2 0.1 0.7%S-SCH -5 10% 29.5 19.5 0.1 0.4%BCH -2 90% 29.9 29.4 0.9 4.4%PICH -7 96% 26.0 25.8 0.4 1.9%PCH -2 20% 32.6 25.6 0.4 1.8%AICH -6 7% 27.0 15.3 0.0 0.2%
FACH-1 1 10% 34.8 24.8 0.3 1.5%FACH-2 1 30% 34.5 29.3 0.8 4.2%
4.2 20.9%Total Power used for Control Channels from a 20W Carrier
CONFIDENTIAL
DL Common Control Channel: Power Calculations example Node-B with RRU
Top of Ref PointNode-B at Antenna Max. Pwr(dBm) Avr. Pwr(dBm) Avr. Pwr (W) % of Tot.
Total Available Power Per Sector 20 W 17.8 33.0 33.0 2.0 10.0% P-CPICH43.0 dBm 0.5 42.5 28.0 18.0 0.1 0.3% P-SCH
28.0 18.0 0.1 0.3% S-SCHCPICH Power 33.0 dBm 32.5 31.0 30.5 1.1 5.7% BCH
2.0 W 1.8 26.0 25.8 0.4 1.9% PICH31.0 24.0 0.3 1.3% PCH27.0 15.3 0.0 0.2% AICH34.0 24.0 0.3 1.3% FACH-1
rel dB Activity Factor 34.0 28.8 0.8 3.8% FACH-2 Not UsedP-CPICH 0 100%P-SCH -5 10%S-SCH -5 10% Max. Pwr(dBm) Avr. Pwr(dBm) Avr. Pwr (W) % of Tot.BCH -2 90% 32.5 32.5 1.8 10.0% P-CPICHPICH -7 96% 27.5 17.5 0.1 0.3% P-SCHPCH -2 20% 27.5 17.5 0.1 0.3% S-SCHAICH -6 7% 30.5 30.0 1.0 5.7% BCHFACH-1 1 10% 25.5 25.3 0.3 1.9% PICHFACH-2 1 30% 30.5 23.5 0.2 1.3% PCH
26.5 14.8 0.0 0.2% AICH33.5 23.5 0.2 1.3% FACH-1
Total Power Used For Common Channels 4.2 W 3.7 33.5 28.3 0.7 3.8% FACH-2 Not Used36.2 dBm 35.7
20.9% 20.9%
Power Available For Dedicated Channels 15.8 W 14.142.0 dBm 41.5
79.1% 79.1%
Description of Common Channel Name Description
P-CPICH Primary Common Pilot Channel Predefined pilot sequence (15kbps, SF = 256), used for UE measurements on DLP-SCH Primary Synch Channel 256 Chip code used for initial slot syncronisation, (256 chips out of every 2560 chip slot).S-SCH Secondary Synch Channel Sequence of 256 chip code words, used for frame sync and SC Group ID (256 chips out of every 2560 chip slot).
P-CCPCH Primary Common Control Physical ChannelCarries the BCH information (system & cell specific using MIBs & SIBs) 15ksps, SF=256. Not transmitted during first 256chips of slot.S-CCPCH Secondary Common Control Physical ChannelUsed to carry FACH and PCH (Only on air when information to carry)
PICH Paging Indicator Channel Carries paging indicators. (SF=256).AICH Acquisition Indicator Channel Carries acquisition indicators to respond to RACH pre-ambles. (SF=256). (4096 chips out of 5120 chips)
Common Channel Allocation Relative to CPICH Power
Huawei Top of Node-B
Huawei at Antenna Input
Huawei
Feeder Loss
CONFIDENTIAL
DL Common Control Channel: Power Calculations example Node-B with Feeder
Top of Ref PointNode-B at Antenna Max. Pwr(dBm) Avr. Pwr(dBm) Avr. Pwr (W) % of Tot.
Total Available Power Per Sector 20 W 10.0 33.0 33.0 2.0 10.0% P-CPICH43.0 dBm 3.0 40.0 28.0 18.0 0.1 0.3% P-SCH
28.0 18.0 0.1 0.3% S-SCHCPICH Power 33.0 dBm 30.0 31.0 30.5 1.1 5.7% BCH
2.0 W 1.0 26.0 25.8 0.4 1.9% PICH31.0 24.0 0.3 1.3% PCH27.0 15.3 0.0 0.2% AICH34.0 24.0 0.3 1.3% FACH-1
rel dB Activity Factor 34.0 28.8 0.8 3.8% FACH-2 Not UsedP-CPICH 0 100%P-SCH -5 10%S-SCH -5 10% Max. Pwr(dBm) Avr. Pwr(dBm) Avr. Pwr (W) % of Tot.BCH -2 90% 30.0 30.0 1.0 10.0% P-CPICHPICH -7 96% 25.0 15.0 0.0 0.3% P-SCHPCH -2 20% 25.0 15.0 0.0 0.3% S-SCHAICH -6 7% 28.0 27.5 0.6 5.7% BCHFACH-1 1 10% 23.0 22.8 0.2 1.9% PICHFACH-2 1 30% 28.0 21.0 0.1 1.3% PCH
24.0 12.3 0.0 0.2% AICH31.0 21.0 0.1 1.3% FACH-1
Total Power Used For Common Channels 4.2 W 2.1 31.0 25.8 0.4 3.8% FACH-2 Not Used36.2 dBm 33.2
20.9% 20.9%
Power Available For Dedicated Channels 15.8 W 7.942.0 dBm 39.0
79.1% 79.1%
Common Channel Allocation Relative to CPICH Power
Huawei Top of Node-B
Huawei at Antenna Input
Huawei
Feeder Loss
CONFIDENTIAL
DL Common Control Channel
• Different quality requirement for the common channels make power planning an important task
Pilot coverage
P-CCPCHcoverage
In this example the mobile "sees" the cell but cannot access it as it cannot decode the BCH
Example values in dBm
CPICH = 33dBmP-CCPCH = 28 dBm (-5)SCH1= SCH2 = P-CCPCH = 28dBm (-5)
Example values in dBm
CPICH = 33dBmP-CCPCH = 28 dBm (-5)SCH1= SCH2 = P-CCPCH = 28dBm (-5)
CONFIDENTIAL
UMTS Protocol Overview
CONFIDENTIAL
UMTS Signaling Protocol Stack
The Non-Access Stratum architecture evolved from the GSM upper layers and includes:
Connection Management – Handles circuit-switched calls and includes sublayers responsible for call control (e.g., establish, release), supplementary services (e.g., call forwarding, 3-way calling), and short message service (SMS).
Session Management – Handles packet-switched calls (e.g., establish, release).
Mobility Management – Handles location updating and authentication for CS calls.
GPRS Mobility Management – Handles location updating and authentication for PS calls.
The Access Stratum architecture is new for WCDMA, and will see in a bit more detail in the next slides
The UMTS signaling protocol stack is divided into Access Stratum (AS) and Non-Access Stratum (NAS).
CONFIDENTIAL
Control Plane Protocol StackThe control plane protocol stack illustrates how signaling protocols are terminated. This example shows a circuit-switched call operating on dedicated Physical Channels.
Access Stratum (AS)• Radio Resource Control (RRC) protocols are defined between UE and RNC to handle establishment, release, and configuration of radio resources.• Radio Link Control (RLC) protocols are defined between UE and RNC to provide segmentation, re-assembly, duplicate detection, and other traditional Layer 2 functions.• Medium Access Control (MAC) protocols are defined between UE and RNC to multiplex user plane and control plane data.• Physical Layer protocols are defined between UE and Node B to transfer data over the radio link. The interface between UE and RNC at the Physical Layer handles macrodiversity combining and splitting functions.
CONFIDENTIAL
User Plane Protocol StackThe user plane protocol stack illustrates how user protocols are terminated. This example shows a circuit-switched voice call operating on dedicated Physical Channels.
Non-Access Stratum (NAS)• Application can consist of several layers. For example, in the case of voice, the topmost layer corresponds to the actual acoustic signals heard by users on both ends, whereas a lower layer carries the vocoded bits. In this protocol architecture, vocoders reside at the UE and at the MSC to translate digitized voice between the format transmitted over the air and that sent over digital wirelines (e.g., E1).Access Stratum (AS)• The RLC, MAC, and Physical Layer protocols for user plane are the same as for the control plane.• RRC does not participate in user plane protocols. It is responsible for setting up the radio bearers and channels, but does not touch the data.
CONFIDENTIAL
Radio Interface Protocol Architecture (in UE)
Radio Resource Control (RRC)
Packet Data Convergence Protocol (PDCP)
Broadcast/Multicast Control (BMC)
Radio Link Control (RLC)
Medium Access Control (MAC)
Layer 1 or Physical Layer (PHY or L1)
Radio Bearers – Carry signaling between RRC and RLC or carry user data from application layers to Layer 2.
Logical Channels – Carry signaling and user data between RLC and MAC.
Transport Channels – Carry signaling and user data between MAC and PHY.
Physical Channels – Carry signaling and user data over the radio link.
CONFIDENTIAL
Access Stratum Layer 3: Radio Resource Control (RRC)
RRC Functions of Access Stratum Layer 3
RRC is the overall controller of the Access Stratum, responsible for configuring all other layers in the Access Stratum and providing the control and signaling interface to the NAS layer.
Radio Resource Control (RRC) Include:
• Broadcast of System Information
• RRC Connection Management
• Radio Bearer Management
• RRC Mobility Functions
• Paging and Notification Functions
• Routing of Higher Layer Messages
• Control of Ciphering and Integrity Protection
• Measurement Control and Reporting
• Power Control Functions
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Access Stratum Layer 2
Layer 2 consists of four sublayers: BMC, PDCP, RLC and MAC.Broadcast/Multicast Control (BMC)
- Involved in the Cell Broadcast Messages
- Storage, scheduling, transmission, delivery
- Request for radio resources
Packet Data Convergence Protocol (PDCP)- Packet data header compression/decompression
Radio Link Control (RLC)- Typical Layer 2 functions
- Segmentation, reassembly, concatenation, padding
- Retransmission control, flow control
- Duplicate detection, in-sequence delivery
- Error correction
- Ciphering
Medium Access Control (MAC)- Mapping and multiplexing Logical Channels to Transport Channels
- Priority handling of data flows
- UE identification on common channels
- Traffic volume measurements
- Random Access Channel procedures
- Ciphering
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Access Stratum Layer 1: Physical Layer
Physical Layer functions are:
Macro-diversity distribution/combining and soft handover
Error detection on Transport Channels
Forward Error Correction (FEC) encoding/decoding
Interleaving/deinterleaving of Transport Channels
Multiplexing/demultiplexing of Transport Channels
Rate matching
Power weighting and combining of Physical Channels
Modulation/demodulation
Spreading/despreading
Frequency and time (chip, bit, slot, frame) synchronization
Measurements (e.g., FER, SIR, interference power, transmit power, etc.)
Closed loop power control
RF processing
CONFIDENTIAL
UE Call States
CONFIDENTIALUE Call States
Idle Mode
The UE operates in Idle mode whenever it has no active CS or PS call.
UE monitors the PCH and the associated PICH. It may “sleep” between paging cycles, by disabling some of its circuitry to improve standby time.
CELL_DCH State
The CELL_DCH state may be entered from the Idle Mode when an RRC connection is established, or when a Dedicated Physical Channel is established from the CELL_FACH state.
PS call may operate in CELL_DCH state, especially if it is a high data transfer
CELL_FACH State
The CELL_FACH state may be entered from the Idle Mode when an RRC connection is established or from the CELL_DCH state when directed by UTRAN to release dedicated channels
UE continuously monitors the FACH, because UTRAN can send it data or signaling at any time (no sleeping!).
CELL_PCH State
The CELL_PCH state may be entered from the CELL_FACH state, when UTRAN detects a lack of activity from the UE during a PS call.
Similar to Idle Mode, the UE monitors the PCH and the associated PICH. It may sleep between paging cycles. If the UE has data or signaling to send, it autonomously transitions to CELL_FACH and transmits on the RACH. The network knows which cell is camped under and pages that cell only. UE is required to perform a cell update procedure (from CELL_FACH) whenever its location changes to a new cell.
URA_PCH State
The URA_PCH state is similar to the CELL_PCH state, except that it is used when UTRAN detects very low activity from the UE during a PS call and wants to limit the number of cell update procedures performed by the UE.
The UE is required to perform a URA update procedure (from CELL_FACH) whenever its location changes to a new routing area. Because a routing area may encompass many cells, the frequency of updates is much lower than for the CELL_PCH state. The tradeoff is that UTRAN must page the UE in all cells of the routing area, rather than in just a single cell. [URA: UTRAN Registration Area}
Thank You
Confidential
CONFIDENTIAL
Support Slides
CONFIDENTIAL
Downlink channel mapping (Ericsson FDD)
BCCHBroadcast Control Ch.
PCCHPaging Control Ch.
CCCHCommon Control Ch.
DCCHDedicated Control Ch.
DTCHDedicated Traffic Ch. N
BCHBroadcast Ch.
PCHPaging Ch.
FACHForward Access Ch.
DCHDedicated Ch.
P-CCPCH(*)Primary Common Control Physical Ch.
S-CCPCHSecondary Common Control Physical Ch.
DPDCH (one or more per UE) Dedicated Physical Data Ch.
DPCCH (one per UE)Dedicated Physical Control Ch.Pilot, TPC, TFCI bits
SSCi
Logical Channels(Layers 3+)
Transport Channels(Layer 2)
Physical Channels(Layer 1)
DownlinkRF Out
DPCH (Dedicated Physical Channel)One per UE
DSCHDownlink Shared Ch.
SHCCHDSCH Control Ch.
CTCHCommon Traffic Ch.
CPICHCommon Pilot ChannelNull Data
Data Encoding
Data Encoding
Data Encoding
Data Encoding
Data Encoding
PDSCHPhysical Downlink Shared Channel
AICH (Acquisition Indication Channel)
PICH (Paging Indication Channel )
Access Indication data
Paging Indication bits
AP-AICH(Access Preamble Indication Channel )
Access Preamble Indication bits
CSICH (CPCH Status Indication Channel )
CPCH Status Indication bits
CD/CA-ICH (Collision Detection/Channel Assignment )
CPCH Status Indication bits
S/P
S/P
Cch
S/P
S/P
S/P
S/P
S/P
S/P
S/P
S/P
Cell-specificScrambling
Code
I+jQ I/QModulator
Q
I
Cch
Cch
Cch
Cch
Cch
Cch
Cch
Cch 256,1
Cch 256,0
GS
PSC
GP
Sync Codes(*)
* Note regarding P-CCPCH and SCH
Sync Codes are transmitted only in bits 0-255 of each timeslot;P-CCPCH transmits only during the remaining bits of each timeslot
Filter
Filter
Gain
Gain
Gain
Gain
Gain
Gain
Gain
Gain
Gain
Gain
SCH (Sync Channel)
DTCHDedicated Traffic Ch. 1
DCHDedicated Ch.
Data Encoding
MUX
MUX
CCTrCH
DCHDedicated Ch.
Data Encoding
CONFIDENTIAL
Uplink channel mapping (Ericsson FDD)
Logical Channels(Layers 3+)
Transport Channels(Layer 2)
Physical Channels(Layer 1)
UplinkRF Out
UEScrambling
Code
I+jQ I/QMod.
Q
I
Chc
I
Filter
Filter
CCCHCommon Control Ch.
DTCH (packet mode)Dedicated Traffic Ch.
RACHRandom Access Ch.
PRACHPhysical Random Access Ch.
DPDCH #1Dedicated Physical Data Ch.
CPCHCommon Packet Ch.
PCPCHPhysical Common Packet Ch.
Data Coding
Data Coding
DPDCH #3 (optional)Dedicated Physical Data Ch.
DPDCH #5 (optional) Dedicated Physical Data Ch.
DPDCH #2 (optional) Dedicated Physical Data Ch.
DPDCH #4 (optional) Dedicated Physical Data Ch.
DPDCH #6 (optional) Dedicated Physical Data Ch.
Q
DPCCHDedicated Physical Control Ch.
Pilot, TPC, TFCI bits
Chd
Gc
Gd
j
Chd,1 Gd
Chd,3 Gd
Chd,5 Gd
Chd,2 Gd
Chd,4 Gd
Chd,6 Gd
Chc Gd
Chc
Chd
Gc
Gd
j
RACH Control Part
PCPCH Control Part
j
DCCHDedicated Control Ch.
DTCHDedicated Traffic Ch. N
DCHDedicated Ch.
Data Encoding
DTCHDedicated Traffic Ch. 1
DCHDedicated Ch.
Data Encoding M
UX
CCTrCH
DCHDedicated Ch.
Data Encoding
CONFIDENTIAL
Signaling Diagrams
CONFIDENTIAL
Mobile OriginatingCall Setup[CS Services]
Figure shows the procedure for the Mobile Originating Call Setup. The Procedure starts with RRC Connection Request and ends with Connect Ack.
CONFIDENTIAL
Mobile TerminatingCall Setup[CS Services]
Figure shows the procedure for the Mobile Terminating Call Setup.
CONFIDENTIAL
Terminating SMS
The procedure for mobile terminated SMS is shown
CONFIDENTIAL
RAB Establishment (MS initiated) [PS Services]
The UE is in PMM-IDLE mode and sends the Service Request messageincluding RAB Assignment to the SGSN.
Precondition for the scenario is that a Packet Service Attach and aPDP Context Activation have been done.
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Packet Service Attach Including PDP Context Activation
The UE shall perform a GPRS Attach to the SGSN in order to obtain accessto the GPRS services. The Packet Service Attach including PDP ContextActivation procedure
CONFIDENTIAL
Contents
WCDMA/UMTS Network Architecture
Core Network Element Overview
UTRAN Network Element Overview
Radio Access Bearer
Introduction to Air-Interface
UMTS-FDD Carriers
Spreading & Processing Gain
DL & UL Channelization Codes
Channel Organization/Mapping in UMTS
DL Common Control Channel Power Settings
CONFIDENTIAL
Scrambling Code Planning Overview
CONFIDENTIAL
Basic Scrambling Code Theory
The Common Pilot Channel (CPICH) is an unmodulated code channel, which is scrambled with the cell-specific primary scrambling code.
One DL scrambling code is used per sector in the base station, and it makes the signals from different sources separable from each other.
The DL Scrambling code is used in the cell selection, reselection, and handover process by the UE to distinguish the desired cell.
The P-SCH and S-SCH are decoded by the UE attempting to find the P-CPICH.
Once connected into the network P-CCPCH broadcasts neighbour lists, so helping the UE to find suitable handover partners.
UMTS uses 512 primary scrambling codes, divided into 64 groups of 8
CONFIDENTIAL
Code Groups
Totally 512 (0…511) DL primary SC are subdivided into 64 (0…63) code
groups each of 8 codes.
Each cell has to be assigned by 1 particular scrambling code.
2 cells for a same sector but with different carriers can have the same SC.
0 0 1 2 3 4 5 6 71 8 9 10 11 12 13 14 152 16 17 18 19 20 21 22 233 24 25 26 27 28 29 30 31. . . . . . . . .. . . . . . . . .. . . . . . . . .. . . . . . . . .. . . . . . . . .
63 504 505 506 507 508 509 510 511
Code Group No.(0,1,….,63)
Total 64 codeGroups
CONFIDENTIAL
Cell Search Procedure
1. The UE acquires slot synchronization by correlating the information on the P-SCH with primary synchronization code, which is common to all cells, and by detecting peak values at the matched filter output.
2. The UE obtains frame synchronization and determines the scrambling code group of the cell (made up by eight primary scrambling codes) by correlating the information on the S-SCH with all secondary synchronization code sequences and by detecting the peak value, since the cyclic shifts of sequences are unique.
3. The UE determines the primaryScramblingCode by correlating the CPICH with all codes within the scrambling code group identified in Step2. When the primary scrambling code has been identified, the Primary Common Control Physical Channel (P-CCPCH) will be detected and the UE is able to read the information on the BCCH.
CONFIDENTIAL
Code Group Segregation64 Code Groups are divided into 3 sets.
Code Group 0, CG-0, will not be used. Reserved since some vendors cannot use SC0
Set A: 45 groups reserved for Macro layer outdoor sites.Set A will be further subdivided:
- Set A1 for current 2007 rollout , and will support
36 x 8codes = 288 codes = 288 cells = 96 sites (1-time reuse)
- Set A2 reserve for initial 2008 rollout of new sites
9 x 8codes = 72 codes = 72 cells = 24 sites
Set B: 9 groups for future expansions 2008/9, which can support9 x 8codes = 72 codes = 72 cells = 24 sites (1-time reuse)
Set C: 9 groups for In-building, Micro and tested cells which can support
9 x 8codes = 72 codes = 72 cells
1 … 36 37 … 45 46 … 54 55 … 63
Scrambling Code Groups
99936
Set CSet BSet A2Set A1
CONFIDENTIAL
Code Group Assignments0 1 2 3 4 5 6 7 0 1 2 3 4 5 6 7
Rsv CG-0 0 0 1 2 3 4 5 6 7 CG-37 37 296 297 298 299 300 301 302 303 aCG-1 1 8 9 10 11 12 13 14 15 a CG-38 38 304 305 306 307 308 309 310 311 bCG-2 2 16 17 18 19 20 21 22 23 b CG-39 39 312 313 314 315 316 317 318 319 cCG-3 3 24 25 26 27 28 29 30 31 c CG-40 40 320 321 322 323 324 325 326 327 aCG-4 4 32 33 34 35 36 37 38 39 a CG-41 41 328 329 330 331 332 333 334 335 bCG-5 5 40 41 42 43 44 45 46 47 b CG-42 42 336 337 338 339 340 341 342 343 cCG-6 6 48 49 50 51 52 53 54 55 c CG-43 43 344 345 346 347 348 349 350 351 aCG-7 7 56 57 58 59 60 61 62 63 a CG-44 44 352 353 354 355 356 357 358 359 bCG-8 8 64 65 66 67 68 69 70 71 b CG-45 45 360 361 362 363 364 365 366 367 cCG-9 9 72 73 74 75 76 77 78 79 c CG-46 46 368 369 370 371 372 373 374 375 a
CG-10 10 80 81 82 83 84 85 86 87 a CG-47 47 376 377 378 379 380 381 382 383 bCG-11 11 88 89 90 91 92 93 94 95 b CG-48 48 384 385 386 387 388 389 390 391 cCG-12 12 96 97 98 99 100 101 102 103 c CG-49 49 392 393 394 395 396 397 398 399 aCG-13 13 104 105 106 107 108 109 110 111 a CG-50 50 400 401 402 403 404 405 406 407 bCG-14 14 112 113 114 115 116 117 118 119 b CG-51 51 408 409 410 411 412 413 414 415 cCG-15 15 120 121 122 123 124 125 126 127 c CG-52 52 416 417 418 419 420 421 422 423 aCG-16 16 128 129 130 131 132 133 134 135 a CG-53 53 424 425 426 427 428 429 430 431 bCG-17 17 136 137 138 139 140 141 142 143 b CG-54 54 432 433 434 435 436 437 438 439 cCG-18 18 144 145 146 147 148 149 150 151 c CG-55 55 440 441 442 443 444 445 446 447CG-19 19 152 153 154 155 156 157 158 159 a CG-56 56 448 449 450 451 452 453 454 455CG-20 20 160 161 162 163 164 165 166 167 b CG-57 57 456 457 458 459 460 461 462 463CG-21 21 168 169 170 171 172 173 174 175 c CG-58 58 464 465 466 467 468 469 470 471CG-22 22 176 177 178 179 180 181 182 183 a CG-59 59 472 473 474 475 476 477 478 479CG-23 23 184 185 186 187 188 189 190 191 b CG-60 60 480 481 482 483 484 485 486 487CG-24 24 192 193 194 195 196 197 198 199 c CG-61 61 488 489 490 491 492 493 494 495CG-25 25 200 201 202 203 204 205 206 207 a CG-62 62 496 497 498 499 500 501 502 503CG-26 26 208 209 210 211 212 213 214 215 b CG-63 63 504 505 506 507 508 509 510 511CG-27 27 216 217 218 219 220 221 222 223 cCG-28 28 224 225 226 227 228 229 230 231 aCG-29 29 232 233 234 235 236 237 238 239 bCG-30 30 240 241 242 243 244 245 246 247 cCG-31 31 248 249 250 251 252 253 254 255 aCG-32 32 256 257 258 259 260 261 262 263 bCG-33 33 264 265 266 267 268 269 270 271 cCG-34 34 272 273 274 275 276 277 278 279 aCG-35 35 280 281 282 283 284 285 286 287 bCG-36 36 288 289 290 291 292 293 294 295 c
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S.C. SetS.C. SetCell
CONFIDENTIAL
Outdoor Macro sites SC Plan (Example)
• For the convenience of displaying and mapping the 8 reuse patterns onto the network, 8 individual colors are assigned to each reuse pattern
R1R2R3R4R5R6R7R8
CONFIDENTIAL
Scrambling Code Polygon Assignment
ReUse Pattern of 8 Polygons
Repeat same pattern until entire area is planned
Even though a perfect pattern cannot be maintained in the real network try to maintain code group distances to avoid Interference
CONFIDENTIAL
KV Scrambling Code Polygon Assignment
Example of KV Re-Use Pattern of the 8 Polygons
CONFIDENTIAL
Throughput Calculations: RLC/MAC & LLC Layers
Coding Scheme N (number of bytes) Radio Block Size Radio Block Throughput (bit/s)CS-1 23 23*8=184 184*50=9200CS-2 33 33*8=264 264*50=13200CS-3 39 39*8=312 312*50=15600CS-4 53 53*8=424 424*50=21200
Table 9. Radio Block Throughput (bits/s). Within the RLC/MAC Layer
Number of TS CS-1 CS-2 CS-3 CS-41 9200 13200 15600 212002 9200*2=18400 13200*2=26400 15600*2=31200 21200*2=424003 9200*3=27600 13200*3=39600 15600*3=46800 21200*3=636004 9200*4=36800 13200*4=52800 15600*4=62400 21200*4=84800
Table 10. RLC/MAC Theoretical Maximum Throughput (bits/s)
Number of TS CS-1 CS-2 CS-3 CS-41 8000 12000 14400 200002 8000*2=16000 12000*2=24000 14400*2=28800 20000*2=400003 8000*3=24000 12000*3=36000 14400*3=43200 20000*3=600004 8000*4=32000 12000*4=48000 14400*4=57600 20000*4=80000
Table 11. LLC Theoretical Maximum Throughput (bits/s)
CONFIDENTIAL
Slides removed
CONFIDENTIAL
Open-Loop (slow) Power Control
Open-loop power control is used for initial power setting of the MS at the beginning of a connection. When the mobile requires access to the network rather than transmit at full power, as is the case in GSM, it uses the following steps to avoid causing interference to other users in the cell:
1. The mobile measures the received power from the Base Station.
2. The mobile read the Base Station transmit power from the broadcast channel.
3. The mobile estimates (calculates) the minimum transmit power necessary to access the Cell and makes an attempt at a power slightly lower.
4. If this attempt is unsuccessful that is, there is no response from the Base Station, it will increase the power and re-try.
CONFIDENTIAL
Inner-Loop (fast) Power Control
Power control is also required in call to avoid mobiles transmitting too much power as they move towards the Base Station. The system must ensure that the mobile only transmits just enough to be received to avoid unnecessary interference to other users.
Another reason for this Fast Power Control is to overcome a phenomenon known as fast or Rayleigh fading, whereby the received signal strength from moving objects experiences very short duration fades that are dependant on the radio frequency and the speed of the object.
Once the connection is established, the mobile (uplink) power, can be controlled by the Base Station by sending power control messages (TPC bits, are used for the downlink power control as well). The power can be adjusted in steps of 0.5 dB at a rate of 1500 times per second.
In example below we can see that as Mobile A moves behind the tree it is told to increase its power by 1 dB. Similarly as Mobile B moves towards the Base Station it is told to decrease its power by 1dB.
CONFIDENTIAL
Outer-Loop power control
The outer loop power control is needed to keep the quality of communication at the required level by setting the target, SIR target or Eb/I0, for the fast power control.
The SIR target for fast control changes in the range of 1 Hz and is set by the RNC and is based on Bit Error Rate (BER) or Frame Error Rate (FER).
The outer loop aims at providing the required quality: no worse, no better, since too high quality would waste the capacity of the system.
If the received quality in UL is better than the required quality then the SIR target is decreased. If not then the SIR target is increased.
In the DL the fastest adjustment of the downlink target is obtained by having the outer loop power control within the mobile.
