WCMDA 01 Radio Network Solution

8/17/2019 WCMDA 01 Radio Network Solution

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COMIT Training Course 1

Oct - 2015


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At the end of this module, you will be able to

• Name the structure of UTRAN specific signalling interfaces

• Understand the RAB QoS parameters

Objectives


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3G RPLS / AA / 10/2008

• In December 1999, the first UMTS Release was frozen. This release is commonly called UMTS Release 99. In thespecification phase, two main objectives had to be met:

•New radio interface solution

•Core Network (CN) evolution

• Mobile communication became a big business case in the 90s with unexpected growth rates.

• In some areas, this imposed capacity problems. There were not enough radio resources available to supply thesubscribers in a satisfying way.

• The 2nd generation mobile communication systems were still optimised for speech transmission.

• Also in the 90s, there was an unprecedented growth in data communications. This was mainly caused by theintroduction of user friendly GUIs, the browsers, to serve in the net, and by the steadily dropping costs forcomputer and router.

UMTS Release 99


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3G RPLS / AA / 10/2008

• Therefore, during the standardisation process, one major focus lay on the radio interface solution.

•It had to be more efficient to serve more subscribers in one geographical area, resp. to allow higher datarates.•On the other hand, more flexibly was required, too, so that all kinds of present and future multimedia

applications could be served.•CDMA was selected as multiple access technology for the radio interface solution. The UMTS radiointerface solution is often called WCDMA, because CDMA is used on 5 MHz.•Two duplex transmission solutions are available with UMTS Release 99, one based on the TDD and onebased on the FDD mode.The introduction of a new radio interface solution required a new design of the whole radio access network, which is called UTRAN.

• CN evolutionThere are more than 500 GSM operators worldwide. So one requirement to UMTS Release 99 was to enable asmooth evolution from 2G to 3G. Therefore, the UMTS Rel99 CN is an enhanced GSM NSS.

UMTS Release 99 (cont.)


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3G RPLS / AA / 10/2008

3GPP Release 4 3GPP Release 4 is a further enhancement of 3GPP Release 1999.

3GPP Release 4 contains, but is not limited to

UTRA FDD repeater function

low chip rate TDD option

700 MHz support for GERAN, e2e transparent packet streaming service

Tandem Free Operation

Transcoder Free Operation

IP transport of CN protocols

bearer independent CS core network

CAMEL enhancements and OSA enhancements.

The 3GPP Release 4 was functionally frozen in March 2001.

(Adopted from TR 21.902)


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3G RPLS / AA / 10/2008

3GPP Release 5 3GPP Release 5 is a further enhancement of the previous releases.

3GPP Release 5 contains, but is not limited to,

High Speed Downlink Packet Access (HSDPA)

Initial phase of the IP Multimedia Subsystem (IMS)

Wideband AMR

Location Services enhancements

UMTS in 1800/1900 MHz bands (release independent)

IP transport in the UTRAN

UTRAN sharing in connected mode and security enhancements.

The 3GPP Release 5 was functionally frozen in March 2002 and the remaining part in June 2002.



7/373G RPLS / AA / 10/2008

3GPP Release 6 Release 6 (frozen 09/2005) . contains, but is not limited to FDD Enhanced Uplink (HSUPA)

FDD Enhanced Uplink - Physical Layer FDD Enhanced Uplink - Layer 2 and 3 Protocol Aspects FDD Enhanced Uplink - UTRAN Iub/Iur Protocol Aspects FDD Enhanced Uplink - RF Radio Transmission/ Reception, System Performance Requirements and

Conformance Testing Location Services enhancements 2 WLAN-UMTS Interworking Rel-6

Security WLAN charging USIM enhancements for WLAN Interworking

IMS Phase 2 Multimedia Messaging (MMS) enhancements

Multimedia Broadcast/Multicast Service (MBMS) AMR-WB extension for high audio quality Push Services and Presence Network Sharing

NOTE: Nokia/NSN RAN releases (RAN1.5, RAN04, RAS05, RAS 06, RU 10..) do not follow strictly the 3GPPreleases



8/373G RPLS / AA / 10/2008

3GPP Release 7 Release 7 (closed 10/2007) with HSPA+ features:

Higher order Modulation 64QAM for the DL; 16QAM for the UL larger Peak Data rates & Capacity

MIMO Antennas: 2x2 MIMO larger Peak Data rates & Capacity

Network Architecture Improvements: Improved latency & efficiency; lower OPEX / CAPEX WLAN charging Direct Tunneling

Continuous Packet Connectivity CPC / VoIP higher efficiency; more capacity; less UE battery consumption

Enhanced UE Receiver more capacity; higher UE throughput Enhanced Cell_FACH

higher throughput in Cell_FACH L2 / RLC Optimisation

less L2 overhead; higher net throughput

(Adopted from Work_plan_3gpp_rel7)


9/373G RPLS / AA / 10/2008

3GPP Release 8 & 9 Release 8 (closed 12/2008)

Enhancements for HSPA+ evolution 64QAM & 2x2 MIMO simultaneously

Peak Rates up to 42 Mbps

….

Long Term Evolution (LTE) as new radio access system

and 3GPP System Architecture Evolution (SAE) /Enhanced Packet Core EPC for GERAN, UMTS and non

3GPP access….

Release 9 (expected to be closed 12/2009)

LTE-Advanced (LTE-A)

3GPP proposal for IMT-Advanced (4G)

Max. Peak Rate (low Mobility) 1 Gbps DL and up to

500 Mbps (UL) Max. Peak Rate (high Mobility) 100 Mbps UL & DL

Bandwidth of up to 100 Mbps expected

Advanced MIMO-antenna systems expected

…

(Adopted from Work_plan_3gpp_rel8)


10/373G RPLS / AA / 10/2008

UMTS Release 99

UMTS Release 4

UMTS Release 5

UMTS Release 6

• UMTS CN = enhanced GSM NSS• UTRAN & WCDMA

• Bearer independent CS domain• Low chip rate TDD mode• UTRA repeater• MMS

• High Speed Downlink Packet Access (HSDPA)• Wideband AMR• Initial phase of the IP Multimedia Subsystem• IP transport in the UTRAN

• Location Services enhancements

• FDD Enhanced Uplink (HSUPA)• IMS Phase 2• Wireless LAN/UMTS Inter-working• Multimedia Broadcast/Multicast Service (MBMS)• Push Services and Presence.

1999

2001

2002

2006

UMTS Releases

UMTS Release 7

UMTS Release 8

2007

2008

• HSPA+ (MIMO & Higher Order Modulation)• Enhanced UE Receiver• Direct Tunneling

• HSPA+ Enhancements• LTE + SAE/EPS

UMTS Release 92009/10

• LTE-A: IMT-Advanced (4G) proposal


11/373G RPLS / AA / 10/2008

UMTS Network Architecture•The UMTS CN can be organised into two main domains:•CS domain

•This domain offers Circuit Switched (CS) bearer services.

•The CS domain is nowadays mainly used for real time data services, including speech and faxtransmission.

•The network entities MSC, GMSC and VLR can be found here.•PS domain

•This domain offers Packet Switched (PS) bearer services.

•It is based on the GSM feature GPRS. Originally, this domain was developed for non-real timepacket switched applications, such as file transfer, email, access to the Internet.

•It is used today mainly for MMS. But there are tendencies to improve its offered QoS, so that realtime services can be offered, too.

•The SGSN and GGSN are located in the packet switched domain. Other specified PS domainentities are the BGF and the CGF, which are often offered as stand alone devices.

•There are also some network elements, which are shared by the packet switched and circuit switched domain. Thecommon 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. Some service solutions affect the access network, too. Seefor instance LCS.


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3G RPLS / AA / 10/2008

CN (Core Network)

circuit switched (cs) domain

Packet Switched (PS) domain

commoncs & psnetworkelements

GERAN

UTRAN WAP

corporatenetworks

PDN

IP-backbone

CGF

Billing

Centre

BGF

Inter-PLMN

Network

PSTN/ISDN

MSC/VLR GMSC

EIRHLR

AC

SGSN GGSN

UMTS Core Network


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3G RPLS / AA / 10/2008

UMTS Release 4 core network In the 3GPP R4 Core Network the MSC evolves to the MSC Server and the MGW.

The MSC Server is responsible e.g. for signalling, paging and collecting charging information whilethe MGW is doing a switching.

MSC Server contains a communication management functionality and is also responsible for amobility management.

The MGW (Multimedia Gateway) main functions are:

To adapt a conventional signalling between the MSC Server or the GCS (Gateway Control Server)and different network interfaces

To connect a user data from an ATM/IP backbone into the RAN or circuit switched networks

To provide tones and announcements to end users

To do a transcoding and signal processing for a user plane when it's needed


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3G RPLS / AA / 10/2008

UMTS Release 4 core network


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UTRAN The UMTS Terrestrial Radio Access Network (UTRAN) is the access network, which was developed withUMTS.

The access network is organised in Radio Network Subsystems (RNS).

Each RNS has one radio resource control unit, called Radio Network Controller (RNC).

The tasks of a RNC can be seen on one figure on the following pages.

In each RNS, there is at least one Node B active, which is connected to its Controlling RNC (CRNC)

A Node B is the 3G base station.

One or several cells can be activated with one Node B. The main features of a Node B can be seen on one figure of the following pages.


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CN

circuitswitched

(cs)domain

packetswitched(ps)

domain

UTRAN

Radio Network Subsystem (RNS)

Radio Network Subsystem (RNS)

Iub

Iub

Iur

Iu-PS

Iu-CS

Uu

Uu

UE

UE

MSC/VLR

SGSN

RNC

RNC

UTRAN


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• WCDMA radio resource management Admission Control, Packet Scheduling, LoadControl, Power Control, Handover Control,Resource Manager.

• Telecom functionality

incl. Location & connection management(Transport Manager), ciphering, Iu and Iubchannel management, ATM switching andmultiplexing

• Maintenance

incl. Fault localisation and reconfiguration• Operation

incl. RNC and Node B parametermodification

RNC Tasks and Functions


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Iub Interface ATM

Uu Interface

WCDMA

Cellular Transmission management Managing ATM switching and

multiplexing over the Iub interface.Control of AAL2/AAL5 connections.Control of the physical transmission

interfaces – E1, PDH, SDH or microwave.

Air Interface management.Controlling Uplink and

Downlink radio paths on the Uu Air Interface. Baseband to RF

conversion. Antenna multi-coupling.

O&M Processing.Interfacing with NMS

and RNC for alarm andcontrol (Operationsand Maintenance)

functions.

Radio Channel functions. Transport to physical channel

mappings. Encoding/Decoding– Spreading/Despreading user

traffic and signalling.

RNC

Node B Tasks and Functions in Rel

99


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• Scrambling Codes

•The scrambling codes are derived from the Gold code family.•They represent pseudo noise sequences.• As a consequence, if there is multi-path propagation in the system, the individual multi-paths can bedetected due the scrambling codes.

•There are 512 primary scrambling codes defined for the downlink transmission.•Uplink, several million scrambling codes are available.• A scrambling code repeats with every 10 ms frame.

• Channelization Codes•The channelization code are used for channel separation within one multi-path.•The channelization codes are orthogonal codes.

•They repeat with each information bit, which has to be transmitted. Data rates and channelization codesare consequently related.•Uplink, user data and control data are code multiplexed on one physical channel.•Downlink, they are time multiplexed.

Key WCDMA Facts


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Duplex Transmission Modes:• Frequency Division Duplex (FDD)• Time Division Duplex (TDD)

Multiple Access:• Code Division Multiple Access (CDMA)

Modulation• Quadrature Phase Shift Keying (QPSK)• 16-QAM (HSDPA)

Bandwidth• 5 MHz

Time Organisation:• 10 ms per radio frame• 15 time slots per frame• 72 radio frames per hyperframe• 2560 chips per timeslot

Spreading• Spreading codes =

channelisation codes scrambling codes• Chip rate: 3.84 Mchips• Channelisation codes = orthogonal codes,

length: depends on spreading factor

• Scrambling codes = pseudo noise codes(derived from Gold code family)length: 38400 chips (10 ms)

Spreading Factors (FDD mode):• UL: 4, 8, 16, 32, 64, 128, 256• DL: 4, 8, 16, 32, 64, 128, 256, 512The spreading factor can be changed every

TTI (10, 20, 40, or 80 ms).

Handover types: Soft & Softer HO (FDD only),Hard Handover;

Key WCDMA Facts in Rel 99


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• Strata were introduced to group protocols related to one aspect of service. In this course, especially the AccessStratum is of importance.

• The Access Stratum (AS) comprises infrastructure and protocols between entities of the infrastructure specificto the applied access technique. In UMTS it offers services related to the data transmission via the radiointerface. It also allows the management of the radio interface on behalf of other parts of the network. Twoaccess strata are defined in UMTS:

•UTRAN – MT•The protocols in use between UTRAN and the mobile phone specify in detail radio interface relatedinformation. AS signalling is used to inform the UE about how to use the radio interface in the ULand DL direction.

•UTRAN – CN•The CN requests the access network to make transmission resources available. The interactionbetween UTRAN and the CN is hereby independent of the interaction between the UTRAN and the

UE. In other words, the UTRAN – CN access stratum is independent of the used radio interfacetechnology.

• In this course, we focus our interest mainly on the transmission of signalling information and related parameters via the radio interface. Consequently, the access stratum between the UE and UTRAN will be discussed in detail.But also Non Access Stratum (NAS) signalling will be outlined. NAS signalling is exchanged between the UEand the serving network. In this course material, this signalling is regarded as part of the non-access stratum.

Access Stratum


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UTRAN

RNC

UE CN Iu edge node

NAS signalling and User datai.e. MM, PMM & CC, SS, SMS, SM

Access Stratum Signalling(Uu Stratum)

RRC

Access Stratum Signalling(Iu Stratum)

RANAP

AS and NAS Signalling


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• When a subscriber requests a network service, he expects to get – and is willing to pay for – a specific end-to-end quality of service.

• In a peer-to-peer communication, the QoS has to be provided between the two participating terminals. TheQoS of an end-to-end bearer service has to be described. Parameter such as minimum bit rate, guaranteed bitrate, and end-to-end delay can be used.

• An end-to-end bearer service may be made available by several operators. This is the situation displayed in the

figure on the right hand side. The UMTS provider offers the UMTS bearer service, a service establishedbetween the UE and a CN edge node (GMSC, GGSN).• The UMTS bearer service and its QoS depends on the underlying bearer services:

•The CN bearer service and the Radio Access Bearer (RAB) Service.• The signalling protocols RANAP between the CN Iu edge node (MSC/VLR, SGSN) and the RNC is used among

others to establish, maintain, modify and release the Iu Bearer Service, which is required to establish the RABbetween the CN Iu edge node and the S-RNC. Between the S-RNC and the UE, the signalling and controlprotocol RRC is used to establish Radio Bearer (RB) Services, which is also required to establish a RAB Service.

• The RRC is used peer-to-peer between the UE and the S-RNC. There are two intermediate devices, which alsohave to be informed about the bearer management: The Node B and – during a soft handover – the D-RNC.The management of the Iub resources to offer adequate QoS to „higher layer“ bearer services is done with theNBAP. This protocol is also used to inform the Node B about the transmission and reception of common anddedicated information on the radio interface Uu. The RNSAP is used between neighbouring RNCs for featuressuch as inter-RNC soft handovers and S-RNC relocation.

UMTS QoS Architecture


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TE TECN

GatewayMT UTRANCN Iu

edge node

End-to-End Service

TE/MT Local

Bearer Service

External

Bearer Service

UMTS Bearer Service = UMTS QoS

CNBearer Service

Radio AccessBearer Service

BackboneBearer Service

Radio

Bearer Service

Iu

Bearer Service

UTRA FDD/TDDService

PhysicalBearer Service

(adopted from TS 23.107)


QoS Management Functions in t e


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TE ext. networkCN GatewayMT UTRAN CN Iu edge node

UMTS BS

Manager

UMTS BS

Manager

UMTS BS

ManagerRAB

Manager

CN BS

Mana-ger

Iu BS

Mana-ger

Ext. BS

Mana-ger

CN BS

Mana-ger

Iu BS

Mana-ger

RadioBS

Mana-ger

RadioBS

Mana-ger

LocalBS

Mana-ger

BB NSMana-

ger

Iu NSMana-

ger

BB NSMana-

ger

Iu NSMana-

ger

UTRAph. BSMana-

ger

UTRAph. BSMana-

ger

SubscrControl

Adm/Cap.

Control

Adm/Cap.

Control

Trans-lation

Adm/Cap.

Control

Adm/Cap.

Control

Trans-lation

(adopted fromTS 23.107)

QoS Management Functions in t eControl Plane

UTRAN S ifi Si lli d


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3G-MSC/VLR

3G-SGSN

UE Node BRNC

RNC

RNS

RNS

RRC

Iur: RNSAP

UTRAN Specific Signalling and

Control Protocols


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• In UMTS, four QoS classes have been defined:• Conversational class

•is the QoS class for delay sensitive real time services such as speech telephony.• Streaming class

•is also regarded as real-time QoS class. It is also sensitive to delays; it carries traffic, which looks real timeto a human user. An application for streaming class QoS is audio streaming, where music files aredownloaded to the receiver. There may be an interruption in the transmission, which is not relevant for

the user of the application, as long as there are still enough data left in the buffer of the receivingequipment for seamless application provision to gap the transmission time break.

• Interactive class•is a non-real time QoS class, i.e. it is used for applications with limited delay sensitivity (so-calledinteractive applications). But many applications in the internet still have timing constraints, such as http,ftp, telnet, and smtp. A response to a request is expected within a specific period of time. This is the QoSoffered by the interactive class.

• Background class•is a non-real time QoS class for background applications, which are not delay sensitive. Exampleapplications are email and file downloading.

• A set of UMTS bearer attributes have been defined to specify the UMTS service. They are listed on the righthand side. When a UMTS bearer is established, modified or released, aspects such as the UE capabilities,subscription profiles and network specific QoS profiles have to be taken under consideration.



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Background

class

Interactive

class

Streaming

classTraffic class

Maximum bit rate

SDU format

informationSDU error ratio

Residual biterror ratioDelivery of

erroneous SDUs

Transfer delay

Guaranteed bit rate

Traffic handlingpriority

Allocation/Retentionpriority

Delivery order

Maximum SDU size

Conversational

class

(adopted from TS 23.107 chap. 6.4.3.3)

UMTS Bearer Attributes


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Services and traffic class Different services and applications set different requirements for the connection over the radio access

network (RAN), i.e. radio access bearer (RAB)

Minimum bit rate Delay

Error protection These different quality requirements can be met by selection of traffic class Conversational class

The most well known use of this scheme is telephony speech (e.g. GSM). But with Internet andmultimedia a number of new applications will require this scheme, for example voice over IP and videoconferencing tools. Real time conversation is always performed between peers (or groups) of live(human) end-users. This is the only scheme where the required characteristics are strictly given by

human perception. Streaming class When the user is looking at (listening to) real time video (audio) the scheme of real time streams

applies. The real time data f low is always aiming at a live (human) destination. It is a one way transport.This scheme is one of the newcomers in data communication, raising a number of new requirements inboth telecommunication and data communication systems. It is characterised by that the time relations(variation) between information entities (i.e. samples, packets) within a flow shall be preserved,although it does not have any requirements on low transfer delay.

Interactive class When the end-user, that is either a machine or a human, is on line requesting data from remote

equipment (e.g. a server), this scheme applies. Examples of human interaction with the remote

equipment are: web browsing, data base retrieval, server access. Examples of machines interaction withremote equipment are: polling for measurement records and automatic data base enquiries (tele-machines). Background class

When the end-user, that typically is a computer, sends and receives data-files in the background, thisscheme applies. Examples are background delivery of E-mails, SMS, download of databases andreception of measurement records.

(adopted from TS 23.107)


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Traffic classBackground

classInteractive

classStreaming

classConversational

class

Speech

Streaming audio

Web browsing

Email

Email (background)

VoIPGaming

Presence

Video call

Streaming video

Services/apps and traffic class

Initially 3G networks do not support all traffic classes and services are implemented withlower quality connections.

G l P l M d l f UTRAN


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• The general protocol model for UTRAN interfaces can be seen in the figure on the right hand side.•It is organised in horizontal and vertical planes.

• There are two main vertical layers:•The control plane is used for signalling and control.

•UTRAN specific signalling protocols had been developed, such as the RNSAP. This is one exampleof an application protocol, as denoted in the figure.•Each signalling and control protocol requires a signalling bearer.

•The signalling bearers in UMTS are based on standard bearer protocols (e.g. ATM).•The user plane describes the user data transport.

•The data streams are transmitted via data bearers.

• Within the transport network layers, there are vertical transport network user and control planes.• A transport network control plane is responsible for the transport of higher layer data.•The transmission resources for the control plane are made available by operation and maintenance.

•The Transmission resources for the user data streams can be made available on demand. On someinterface, ALCAP is used.•It is a transport network control plane specific signalling protocol to establish, maintain, modify, andrelease data bearers. It is for instance in use on the Iu-CS interface, but not on the Iu-PS interface. Thesignalling bearers for ALCAP are always set up by operations and maintenance.

General Protocol Model for UTRAN

Interfaces



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Physical Layer

(copied from TS 25.401 chap. 11.1.1)

Control Plane User PlaneRadioNetworkLayer

TransportNetwork

Layer

ApplicationProtocol

SignallingBearer(s)

SignallingBearer(s)

DataBearer(s)

ALCAP

DataStreams

Transport NetworkControl Plane User Plane

Transport Network

User Plane

Transport Network


Interfaces


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• The figure on the right hand side shows the Uu access stratum protocols as implemented in the UE.

• The UE protocol stack can be divided into a control and a user plane.

• The L3 protocol RRC is used to inform the UE about the use of the uplink and downlink radio resources.

• The RRC protocol‘s peer entities are the RNC and the Node B.

• The receiving entity has to configure the L2 (MAC, PHY, PDCP, and BMC) protocol entities in accordance to thereceived commands.

•MAC: Medium Access Control•PHY: Physical layer•PDCP: Packet Data Conversion Protocol•BMC: Broadcast/multicast control

• The protocol stacks for signalling and user data transfer can be seen with the two figures, which follow the nextone.


Interfaces

Radio Interface Protocol Architecture


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MAC Layer

RLC Layer

PHY Layer

(copied from TS 25.301 chap. 5.1)

Control Plane Signalling User Plane Signalling

RRC Layer

TrCHs

RLCRLCRLC

RLC

RLCRLC RLC

RLC

BMC

PDCPPDCP

PDCP

PhyCHs

LogCHs

RBs

control

controlcontrol

control

control

Radio Interface Protocol Architecture

(in UE)


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For this course module, following 3GPP specifications were used:

• TR 21.902, Evolution of 3GPP system• TS 23.002, Network architecture• TS 23.101, General UMTS Architecture• TS 23.107, Quality of Service (QoS) concept and architecture• TS 25.301, Radio interface protocol architecture• TS 25.308, UTRA HSDPA; Overall description; Stage 2• TS 25.401, UTRAN overall description• TR 25.876, MIMO in UTRA• TS 25.308, HSDPA – Overall Description• TS 25.309, FDD Enhanced Uplink (HSUPA) – Overall Description• TS 36.300, E-UTRA and E-UTRAN Overall Description• TR 36.913, LTE-Advanced

TS Technical SpecificationTR Technical Report

Remark:Most of these Specifications are available in different versions, mainly depending on the 3GPP Release. HSDPA is

only available starting with Release 5; therefore, HSDPA is only contained in Version 5 or later specifications.Release 99 is referred to as Version 3. Modifications within one release are possible, resulting in runningnumbers.

Example: TS 25.401 V3.10.0 gives an overall description of UTRAN based on Release 99. 10.0 refers to 10 (by3GPP) approved versions with minor corrections.

References

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WCMDA 01 Radio Network Solution

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