3g protocals and proccedures

WCDMA RAN Protocols and Procedures

Agenda

oWCDMA System Architecture

oRadio interface

oIUB ,IUR and Iu interface

oRRC (Radio Resource controller )Protocols

oRLC (Radio link controller) Protocols

oMAC and Physical layer function

BTS

GSM BSS

Node‐b RNC

WCDMA Systems RAN

MSC / VLR GMSC

MGW

SGSN GGSN

IP Network

Abis

Gb

Iub IuIu-Ps

Iu-CS

SGSN •Handle the PS services to and from the UE. •Forwards incoming and outgoing IP packets addressed to/from an UE that is attached within the SGSN SA •Provides functions such as ciphering and authentication, session management and mobility management

GGSN•Interface to the external IP packet network

MGW •Connects the Core Network to the RNC •CS traffic. •Cross connection between the RNC and the SGSN.

WCDMA System Architecture

PCU

BSC

RNC

RNC

UE WCDMA RAN Core Network

MSC

MGW

SGSN

GGSN

•Every interface contains protocols used over it.

•Protocol used over the Iub interface

oNode B Application Part Protocol (NBAP).

•Protocol used over the Iur interface

oRadio Network Subsystems Application Part (RNSAP).

•Protocol used over the Iu interface

oRadio Access network application part(RNAP)

NAS MessagesoSignaling between the UE and CN directly

Uu Iub

IUR

WCDMA RAN Interfaces.Iu

NAS messages

RNC

CS Domain

MGW

MSC

GGSN

WCDMA RAN

Iu‐Bc

SGSN

CBC

PS Domain

Broadcast domain

Cell Broadcast center

WCDMA RAN Interfaces (Cont’d).

•The Iu interface to the circuit switched domain, i.e. to the MSC, is referred to as Iu‐CS.

•The Iu interface to the packet switched domain, i.e. to the SGSN, is referred to as Iu‐PS.

Iu‐PS

In band Signaling

Direct tunneling

data

Signaling

Core Network

Iu‐CS

Protocols in WCDMA RAN

•UE needs to contact the network which can be triggered either by:

oSystem information (Location Area Updating or Routing Area Updating)

oTimer expiring (Periodic Registration)

oPaging message received

oUE wants to initiate a call setup (Mobile Originating)

•Exchange of signals between two entities. oWhat nodes are involved ?o What kind of information needs to be exchanged over the different interfaces?

•Why protocol ?oTo be able to understand the kind of signaling messages that need to be sent and how they are transmitted over the interfaces

Protocols in WCDMA RAN(Cont’d)Location Update•UE performs location updating

oTo keep the network up to date with the subscriber’s location .oUE doesn’t miss incoming calls

•How the UE gets information regarding the Location Area Identity (LAI) of the serving cell ?oWhen the UE is idle, it listens to the system information on BCCH.

1

1‐UE reads from system information that the LAI is not the same as that stored in the USIM. This triggers the UE to update the location area.

2‐UE tries to access the network and sends a request message to the RNC, via the RBSThe RNC checks if it is possible to allocate a dedicated channel to the UE.

3‐ Resources in the RBS and over the Iub interface are reserved by the RNC and are ACK by the RBS

4. Information about the new channel is sent to the UE with a setup message.

5. Synchronization is achieved between the UE and the RBS, and the UE sends a complete message.

22

3

4

5

RNC

Example :LOCATION UPDATING

1

22

3

4

5

VLRRNCMSC

6

6‐The UE sends the request to update the location information to the CN.oThis message also carries the IMSI and LAI. oIu signaling bearer is set up between the RNC and the CN. oThere is now a signaling connection between the UE and the CN. oAs this is the first time the UE accesses this service area the subscriber is unknown in the VLR.

7‐The VLR sends a request to the subscriber’s HLR for Authentication Information.

8‐ The HLR sends this information to the VLR.

9‐MSC/VLR starts to authenticate the subscriber. oThis message is transparent over WCDMA RAN.

10‐After Authentication, the VLR asks the HLR to update its Location information for the IMSI and with thenew VLR address

11‐ VLR receives an acknowledgement from the HLR.

12‐The MSC/VLR transmits an acceptance to the UE, UE updates the location information in the USIM.

13‐ The signaling connection is released. First the UE is told to release the connection then the RBS

HLR

7

8

9

10

11

1213

Location Update and Routing area update(Cont’d)

LAYERED STRUCTURE OF PROTOCOLS

LAYERED STRUCTURE OF PROTOCOLS

oSignaling message travels down in the protocol stack of the sending node.

oThe layers on the way add their specific information to the original message.

oMessage arrives at a receiving node.

oHandled upwards in the protocol stack, each layer in the receiving node analyzing information added by the peer

protocol.

110010110010

1001010010

010010

Peer layers

User Data

Correction

addressing

INTRODUCTION TO RADIO INTERFACE (Uu)

UE

INTRODUCTION TO RADIO INTERFACE, UU

The interface is layered into three protocol layers:

oThe physical layer (L1);

oThe data link layer (L2);

o Network layer (L3)

Layer 3

Layer 2

Layer 1

Physical layer (L1)

Data link layer (L2)

Network layer (L3)

Layer 3 (Network layer )

oLayer 3 consists of one protocol, called Radio Resource Control (RRC), which belong to the control plane.

o Function of RRC is to establish Signaling Radio Bearers between the UE and the RNC to handle most of the

control signals.

oRRC controls the lower layers

Note :

oMessages that are not meant for the RAN but for the CN are called Non Access Stratum (NAS)

oTransferred transparently over the WCDMA RAN.

INTRODUCTION TO RADIO INTERFACE, Uu

Layer 3RRC

NAS

Control Plane

INTRODUCTION TO RADIO INTERFACE, Uu (Cont’d)Layer 2 (Data link layer) oLayer 2 is split into different sub layers.

A‐ Radio Link Control (RLC) B‐Medium Access Control (MAC)

Layer 3RRC

NAS

Control Plane

Layer 2

RLC

MAC

User Plan (User data)

Signaling Radio Bearers Radio Bearers

RLC layer (Radio Link Control)oRLC layer provides service in both

A‐Control plane is called Signaling Radio Bearer (SRB) B‐User plane it is called a Radio Bearer (RB).

oSignaling Radio Bearer, SRB Signaling messages between the UE and the RNC.

oRadio Bearer, RB. User data transport between the UE and the RNC.

oRLC make sure the messages have correct lengthLong messages convert them to segmentsShort messages add padding bits to them

oRLC instance is configured by RRC to operate in one of three modes depending on the service : Transparent Mode (TM).Unacknowledged Mode (UM) ,Acknowledged Mode (AM),

oRLC map messages on different logical channels.

Control Channels

Broadcast Control Channel (BCCH, DL)Downlink channel for broadcasting system information.

Paging Control Channel (PCCH, DL)Downlink channel that transfers paging information

Common Control Channel (CCCH, DL & UL)Used by the UE needs to access the network.

Dedicated Control Channel (DCCH, DL & UL)Point‐to‐point bi‐directional channel Transmits dedicated control information between UE and network.

Traffic ChannelsDedicated Traffic Channel (DTCH, DL & UL)

Point‐to‐point channel, dedicated to one UE,Transferring user Information.

Common Traffic Channel (CTCH, DL)Traffic channel for sending traffic to a group of UE’s

logical channels

INTRODUCTION TO RADIO INTERFACE, Uu (Cont’d)

RLC

SRB

Logical Channels

RB

Logical Channels

Control Plane User Plan (User data)

MAC layer Medium Access Control oLogical channels received from the RLC layer are mapped onto the transport channels.oMultiplex signaling and data to transport channels


Common transport channel(Several users use the same channel)‐Broadcast Channel (BCH) (DL)

Continuous transmission of system and cell information

‐ Paging Channel (PCH) (DL)When the network wants to initiate communication with the terminal.

‐Random Access Channel (RACH) (UL)The RACH is an uplink transport channel used to make requests to set up a connection

‐Forward Access Channel (FACH) (DL)Control signaling during call setupPacket data transmission in low rates

‐High Speed Downlink Shared Channel (HS‐DSCH)(DL)HSDPA

Transport channels

Dedicated transport channel(For exclusive use of one user) ‐Dedicated Channel (DCH) (UL & DL)

Service data, such as speech frames

Layer 2RLC RLC

Logical Channels Logical Channels

MAC

Transport Channels

BCCHBroadcast Control Ch.

PCCHPaging Control Ch.

CCCHCommon Control Ch.

CTCHCommon Traffic Ch.

DCCHDedicated Control Ch.

DTCHDedicated Traffic Ch.

Logical Channel

BCHBroadcast Ch.

PCHPaging Ch.

FACHForward Access Ch.

DCHDedicated Ch.

HS‐DSCHHigh Speed DLShared Ch.

DCHDedicated Ch.

HSDPA

CPICHCommon Pilot Channel (Aids

channel estimation )

P‐CCPCH(*)Primary Common Control Physical Ch.

S‐CCPCHSecondary Common ControlPhysical Ch.

DPDCH (one or more per UE)Dedicated Physical Data Ch.

DPCCH (one per UE)Dedicated Physical Control Ch.

Pilot /TPC /TFCI

AICH Acknowledges that RBS has acquired a UE Random Access attempt

(Acquisition Indicator Channel)

PICH(Paging Indicator Channel )

HS‐ PDSCH (one or more per UE)High Speed Physical Downlinkshared Ch

HS‐SCCH (<=4 per UE)High Speed Shared Control Ch

MUX

Transport Channels Physical Channels

S/P

CH Code

SC code

Gain

I/QModulator

Primary Common Control Physical Channel (PCCPCH)Broadcast Channel (BCH)

Transport Channel Physical Channel

RBS

Channel mapping

Secondary Common Control Physical Channel (SCCPCH)

Physical Downlink Shared Channel (PDSCH)

Forward Access Channel (FACH)

Paging Channel (PCH)

RACH

DSCH

DCH

UE

Dedicated Physical Control Channel (DPCCH)

DCCH /DTCH

Paging Control Channel (PCCH)

Common Control Channel (CCCH)

Broadcast Control Channel (BCCH)

Physical Common Packet Channel (PCPCH)

Dedicated Physical Data Channel (DPDCH)

Logical Channel

Physical Random Access Channel (PRACH)

Different MAC entities depend on the traffic type:

oMAC‐b handles the transport channel for the broadcast channel.

oMAC‐c handles the transport channels for common channels

oMAC‐d handles all dedicated transport channels

oMAC‐hs handles the HS‐DSCH transport channels

oMAC‐e handles the EUL



Layer 3RRC

NAS

Control Plane

Layer 2

RLC

MAC


SRB

Logical Channels Logical Channels

Transport Channels

RB

Layer 1 (physical layer)

oTransport channels are mapped onto the physical layer.oModulationoCodingoSpreadingoScrambling

oMapped to combination of:Carrier frequencyCodes (channelization/scrambling code pair)Relative phase (UL only)

Layer 1Physical Layer

L3RRC

Control Plane

L2

RLC

MAC


Logical Channels

Transport Channels

PHY L1

RRC

Control Plane

RLC

MAC


Logical Channels

Transport Channels

PHY

Layer 1

FP

AAL2

ATM

Layer 1

FP

AAL2

ATM

RNCNode‐B

L3

L2

L1

Exchanges of signaling and user data between the UE and the UTRAN

SRB

Radio Bearer

RA

B

UTRAN

CN‐CS

CN‐PS

Signaling connection

Radio Bearer Iu Bearer

oSC provides confidential transport of signaling between UE and CN

oRAB provides confidential transport of user data between UE and CN

oThe signaling Radio Bearers, SRB, can carry layer 3 signaling (RRC connection establishment),

oA Radio Bearer responsible for transfer of data between UE and UTRAN.

oRadio bearers are mapped successively on logical channels, transport channels and physical channels

SCSRB Iu Signaling Bearer

Signaling connection

Iu Bearer

Iu Signaling Bearer

CNRNC

Traffic Channel

RRC Channel

‐‐‐‐‐‐‐‐‐‐‐‐‐‐Radio Bearer‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐

‐‐‐‐‐‐‐‐‐‐‐‐‐‐Signaling Radio Bearer‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐

‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐RAB‐‐‐‐‐‐‐‐‐‐ ‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐

‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐Signaling Connection‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐

CNRNC

HSDPA RAB ‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐Streaming (TV)

HSDPA RAB ‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐interactive (Browsing)

HSDPA RAB ‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐Background (Email)

SRB

Iu‐PS Signaling (RANAP)

Conversational ‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐Voice Call

Iu‐CS Signaling (RANAP)

SGSN

MGW

oA user can have several RABs in case several services are required for this user.

Four Major traffic classes can be identified:

Traffic class

Conversational class

conversational RT

Streaming classstreaming RT

Interactive classInteractive best

effort

BackgroundBackground best

effort

Fundamentalcharacteristics

High Protectionas there is no

Retransmission Protocol

No Delays in both ways

High Protectionas there is no

Retransmission Protocol

Mini Delay (Buffers

compensate the Delays)

Request and Response

Re transmission Protocols are used

Delays are Accepted

Example of theapplication voice streaming video Web browsing Emails

oExample for protocols used when delivering message from UE to CN

oMessage from UE to CN (NAS message)

NAS includes Mobility Management (Location area update)Short Message Services (SMS).

NAS

RRC

RLC

MAC

Layer 1Layer

1

FP

AAL2

ATM

Layer 1

SCCP

ATM

NNI ‐SAAL

MTP ‐3b

Layer 1

RANAP

AAL5

FP

AAL2

ATM

Layer 1

RRC

RLC

MAC

SCCP

ATM

NNI ‐SAAL

MTP ‐3b

Layer 1

RANAP

AAL5

NAS

Uu IUBIU

Peer

Exchanges of signaling between the UE and the CN

RNCNode‐B CN

NAS messages

RRC (Radio Resource Controller)

RRC provides the following functions:

Broadcast of system information

Initial cell selection and cell re‐selection.

Paging.

Establishment, maintenance and release of an RRC connection between the UE and RAN.

Transparent message transfer.

Establishment, reconfiguration and release of Radio Bearers.

oCapacity managements .

RRC connection mobility functions.

oHandover evaluation

UE measurement reporting and control of the reporting.

oTake the decisions based on measurements report

RRC (Radio Resource Controller) Cont’d

Example for RRC Messages..

oRRC Connection RequestoRRC Connection SetupoRRC Connection RejectoRRC Connection Setup CompleteoRRC Connection ReleaseoRRC Connection Release CompleteoPaging Type 1 (CS Idle)oPaging Type 2 (CS connected)oRadio Bearer SetupoRadio Bearer Setup CompleteoRadio Bearer Setup FailureoRadio Bearer ReconfigurationoRadio Bearer Reconfiguration CompleteoRadio Bearer Reconfiguration Complete FailureoRadio Bearer ReleaseoRadio Bearer Release CompleteoRadio Bearer Release FailureoPhysical Channel ReconfigurationoPhysical Channel Reconfiguration CompleteoPhysical Channel Reconfiguration Complete Failure

oURA UpdateoURA Update ConfirmoCell UpdateoCell Update ConfirmoActive Set UpdateoActive Set Update CompleteoActive Set Update FailureoCell Change Order From WCDMA RANoCell Change Order From WCDMA RAN Failure


RRC FUNCTIONS AND PROCEDURES

1‐ BROADCAST OF SYSTEM INFORMATIONThe System Information messages are sent on BCCH logical channel


WCDMA RANBCCH on BCH or FACH

The UE reads system information on the BCCH when following occur:‐ The UE is powered up‐ The UE changes cell in Idle mode or in state CELL_FACH‐ The UE is informed of a change of System Information.‐The UE moves from dedicated mode to common mode

BCCH (Logical) BCH(Transport)DL idle

DL FACH BCCH (Logical) FACH(Transport)

P‐CCPCH(*)Primary Common Control Physical Ch.

S‐CCPCHSecondary Common ControlPhysical Ch..

2‐ INITIAL CELL SELECTION AND CELL RESELECTION

After the UE has read the system information, it shall use the cell selection and Reselection parameters and choose the most suitable cell to camp on.

Cell selection procedure

oSqual = Qqualmeas ‐ qQualMin (For WCDMA)

Qqualmeas is CPICH Ec/NoqQualMin is minimum required Ec/No

oSrxlev = Qrxlevmeas ‐ qRxlevMin (for all cells)

Qrxlevmeas is CPICH RSCPqRxlevMin is minimum required RSCP

oThe cell consider as accepted if

•Squal > 0 and Srxlev > 0


Cell selection occurs whenUE is switched onUE goes from common channel(cell‐FACH) to idle modeUE goes from connected mode (cell‐DCH) to idleUE goes to idle mode after an emergency call on any PLMNUE in idle mode has had a number of failed RRC connection request

Cell reselection procedure

When it occurs

When cell on which it is camping is no longer suitable

When there is any neighbor with better quality than the selected one

When the UE in the limited service state on an acceptable cell

When the UE is in cell _FACH state

3G F1 3G F2 GSM

3G F1

2‐ INITIAL CELL SELECTION AND CELL RESELECTION (Cont’d)


1‐ Intra frequency measurements starts when

Squal <= Sintrasearch

SintraSearch : Controls when intra‐frequency measurements are performed

Qqualmeas ‐ qQualMin <= Sintrasearch

Qqualmeas <= Sintrasearch + qQualMin

2. Inter frequency measurements starts when

Squal <= SinterSearch

Sintersearch : Controls when intra‐frequency measurements are performed

Qqualmeas ‐ qQualMin <= SinterSearch

Qqualmeas <= SinterSearch + qQualMin

Cell reselection procedure(Cont’d)



3. GSM measurements starts when

Squal <= sRatSearch

Qqualmeas <= sRatSearch + qQualMin

OR Srxlev <= SHcsRat

Qqualmeas <= sHcsRat + qrxlevmin

sRatSearch : Controls quality (Ec/No)Threshold at which GSM measurements are performedSHcsRat : Controls Signal Strength Threshold at which GSM measurements are performed




GSM measurement

Time

Qqualmin‐18

‐14

Qqualmeas

SRAT Search=4dB




Qqualmeas <= Sintrasearch + qQualMin

GSM measurement

Time

Qrxlevmin‐115

‐112

QRxlevmeas

sHcsRat =3dB




Qqualmeas <= sHcsRat + qrxlevmin

oWhen the UE triggers a cell reselections procedure it starts ranking for the cell satisfy S‐criteria o(Squal > 0 and Srxlev > 0)

oRanking is done for the serving cell and the neighbor cell

oR(serving)= Qmeas(s)+qHyst(s)

oR(neighbor)= Qmeas(n)‐qOffset(s,n)

oQmeas: is the quality value of the received signaloCPICH Ec/No oCPICH RSCP

oqHyst(s): hystersis value sent to mobile in system information used to delay the reselection oqHyst1 if the ranking based on CPICH RSCPoqHyst2 if the ranking based on CPICH Ec/No

oqOffset(s,n): is the offset between the serving and the neighbor cell also used to shift the cell boarderoqOffset1sn : if the ranking based on RSCP.oqOffset2sn : if the ranking based on Ec/No

oqualMeasQuantityoParameter that determine if we will do the ranking based on RSCP or Ec/No

o The UE reslect the better cell if it stay better for time interval more than Treselection




Time

Qmeas

R(S)

qHyst2=4

R(n)

Qmeas(S)

Qmeas(n)

qOffset2SN=o

TreSelection

Cell Re‐Selection to Neig

R(n) >R(S)




UMTS to GSM cell Reselection

Time

Qmeas

R(S)

qHyst1=4

Qmeas(n) (GSM)

qrxlevmin+SHcsSearch

Qmeas(S)Qrxlevmin

GSM measurements

S‐criteriaSrxlev > 0

Srxlev > Qrxlevmeas ‐ qRxlevMin

Qmeas(S)< qrxlevmin+SHcsSearch

R(N)

qoffset1SN

R(N)>R(S)

TreSelection

Cell Re‐Selection to Neig (GSM)




3G States Introduction

oUE has dedicated channelo(DCCH) for control signaling o (DTCH) is used for user data TransmissionoDCCH and DTCH are mapped onto dedicated transport channels (DCH).oThe UE performs measurements and sends reports to the RNC

Cell FACH DL /UL

CELL DCHDL/UL

Cell PCHDL only

oUE has no dedicated channel allocatedoUE uses the common channels, RACH and FACH, for signaling messages and small amounts of data (Transport Channels)oUE needs to send Cell Update messages to RNC every time it selects a new cell.

oUE can only be reached via the Paging Indicator Channel (PICH).oBattery consumption of the UE very low because:

PICH includes (DRX) functionality.UE does not have to monitor the FACH any more.

If the network initiates any activityPage the UE. When the UE receives the paging it changes to the CELL_FACH stateperforms a Cell Update.

IF UE initiates any activity it triggers a switch to the CELL_FACH state

oA UE on FACH is switched down to Cell_PCH if it shows no activity for a long period of time (system resources are freed)oWhen extended inactivity on both the uplink and the downlink, a Cell_PCH state will be switched down to IDLE


Idle


3‐ PAGINGThis procedure is used to transmit paging information to selected UE in

oIdle modeoCELL_PCH or URA_PCH state.oCell FACH and Cell DCH

oPICH is used to indicate to the UE when it should read the SCCPCH (Physical channels)

WCDMA RAN”Paging type 1” PCCH/PCH

DCCH(Logical) FACH (Transport)

CELL_DCHCELL_FACH

Idle /PCH

WCDMA RAN”Paging type 2” DCCH

DL DCH FACH

PCCH (Logical)Paging Control Ch.

PCH (Transport)Paging Ch. S‐CCPCH (Physical)

Secondary Common ControlPhysical Ch.

DL Idle

4‐ESTABLISHMENT, MAINTENANCE AND RELEASE OF RRC CONNECTION


RNC

RRC Connection Setup” CCCH/FACH

”RRC Connection Request” CCCH/RACH

RRC Connection Establishment

”RRC Connection Setup Complete” DCCH/DCH

WCDMA RANConnected

Mode

CCCH (Logical Channel)Common Control Ch.

FACH (Transport Channel)Forward Access Ch.

S‐CCPCHSecondary Common Control (Physical Ch.)

CCCH (Logical Channel)Common Control Ch.

RACH (Transport Channel)Forward Access Ch.

PRACH(Physical Ch.)

UL

DL

Establishment Cause for RRC connectionoOriginating Conversational CalloOriginating Streaming CalloOriginating Interactive CalloOriginating Background CalloTerminating Conversational CalloTerminating Streaming CalloTerminating Interactive CalloTerminating Background CalloEmergency CalloInter‐RAT Cell Re‐SelectionoInter‐RAT Cell Change OrderoRegistrationoDetachoCall Re‐Establishment


4‐ESTABLISHMENT, MAINTENANCE AND RELEASE OF RRC CONNECTION (Cont’d)

RNC

DCCH:”RRC Connection Release”

DCCH:”RRC Connection Release Complete”

CELL_DCH

CCCH/FACH: ”RRC Connection Release”

CCCH/RACH: ”RRC Connection Release Complete”

CELL_FACH

PICH

CCCH/RACH: ”RRC Connection Release Complete”

URA_PCH PCCH (RRC Connection Release)

Release the RRC connection causeWhen contact with the UE is considered lostWhen RAN has received a request from the CN to release the signaling connection.RAN detects a need to release the connection.


URA_PCH no uplink channel in URA

SIGNALING CONNECTION

RANAP

Iu TransportLayer

RRC

RLC

MAC

L1

RANUE

One RRC Connection

CS

PS

RRC

RLC

MAC

L1

Iu TransportLayer

MSC

RANAP

Iu TransportLayer

CN 1

SGSN

CN 2

oSignaling Connection is a connection between one Core Network (CN) and one UE oThe Signaling Connection consists

one RRC Connection over RAN one or two signaling connection over Iu interface

oEstablishment of the first Signaling Connection is initiated by the UE as soon as the RRC Connection is successfully established.


SC

SC

SC

RANAP

Note that only one RRC Connection is used.

Signaling Connection Release


RANAP

Iu TransportLayer

RRC

RLC

MAC

L1

RANUE

RRC

RLC

MAC

L1

MSC

RANAP

Iu TransportLayer

CN 1

RNC”Signaling Connection Release”RAB

One RRC Connection

oA signaling connection normally exists in conjunction with a RABoHowever, in some cases a signaling connection is established to perform control plane actions that do not involve any user plane action, such as location area updating.oSignaling connection release procedure is used to notify the UE that one of its signaling connections has been released.oThis procedure does not initiate the release of the RRC connection.

SC

UE location area updating

TRANSPARENT MESSAGE TRANSFER


RANAP

Iu TransportLayer

RRC

RLC

MAC

L1

RANUE

RRC

RLC

MAC

L1

MSC

RANAP

Iu TransportLayer

CN 1

RNC

SC

One RRC Connection

”Initial Direct Transfer” (DCCH)

oThe UE sends “Initial Direct Transfer”oThis message carries the initial NAS message from the UE to the CN (Reason for the access)

RAN CN

RRC: ”RRC Connection Request”

RRC: ”RRC Connection Setup”

”RRC Connection Setup complete”

Initial Direct Transfer” NAS: (Service Request)

RRC: ”Uplink Direct Transfer” NAS: (Setup) (i want to make a call)

RRC: ”Downlink Direct Transfer” NAS: (Authentication Request)

RRC: ”Security Mode Complete”

RRC: ”Security Mode Command”

RRC: ”Radio bearer Setup complete”

RRC: ”Downlink Direct Transfer” NAS: (Call Proceeding)

RRC: ”Radio Bearer Setup”

Transfer of NAS messages at Mobile Originated Call Setup

Authentication Response

Check Iu resources

Check RNC resources and QOS

RAB Assignment Request


RADIO BEARER MANAGEMENT

RRC performs oRadio Bearer establishment,oRadio Bearer reconfiguration oRadio Bearer release.

RRC

RLC

MAC

L1

RANAP

Iu TransportLayer

RANAP

Iu TransportLayer

RRC

RLC

MAC

L1

CNRANUE

RAB Assignment RequestRB Manage

RNC RAB Assignment Request

RB Setup Complete

CN

Admission Control,

Radio Bearer Setup”

Set QoS requirements


RB Reconfiguration Complete

CN

RB Reconfiguration


Radio Bearer Release Complete

CN

Radio Bearer Release

Radio Bearer Setup

Radio Bearer Reconfiguration

Radio Bearer Release


CELL UPDATE

oWhile in connected mode (DCH) the UE is always in SOFT handoveroWhen finish the call (common channels) oI have to send cell update oTo tell the network where I am


RNC

”Cell Update Confirm” DCCH on FACH

”Cell Update” CCCH on RACH

CCCH (Logical) RACH(Transport) PRACH (Physical Ch.)Physical Random Access Ch.

UL

DLDCCH(Logical) FACH(Transport) S‐CCPCH (Physical)

Secondary Common Control Physical

Cell Update

The purpose of the cell update is to update the current location of the UE when it is inCELL_FACH /Cell PCH state.

In FACH/ CELL PCH Cell update can be initiated with the following cause values:

oPeriodic Cell update (expiry of timer) T305oCell Selection/ Reselection


What is the radio link supervision ?Is the algorithm supervises the radio connection between the UE and the UTRAN

ReasonoCheck if the UTRAN still control the UE or not.oIncrease the efficiency of resources usage.

FACH oCell Update Message will be sent when:

When the UE change its serving cellWhen t305 expires

Radio Link Supervision (Periodic Cell update (expiry of timer) T305)

UE Enters Cell FACH

T305 expires

Cell Update Message

Cell Update Confirmation

CCHWAITCUT Reset

Overall Connection Release

T305CCHWAITCUT Expire

CCHWAITCUT Start CCHWAITCUT

RLC Protocols

User data

RLC SDURLC PCI

RLC Layer 2

PayloadRLC PCI

MAC SDU

Layer 1

User data

RLC SDU

PayloadRLC PCI

MAC SDU

Layer 1

MAC Layer 2

Uu

SDU service data unit is what I get from higher layersRLC PCI Protocol control information is added to get PDU protocol data unit (headers)

RLC Layer 2

MAC Layer 2

RLC PDU

RLC Protocols

User dataRLC

MAC SDU

RLC PDU

1‐Segmentation and re‐assemblyoI don’t know the user data size so I make segmentation into block size to feet the PDUoReassembly I have to do the opposite on the other side

PayloadRLC PCIRLC PDU

RLC PDU

Uu

PayloadRLC PCI

PayloadRLC PCI

User data

RLC

MAC SDU

RLC PDU


RLC PDU PayloadRLC PCI

PayloadRLC PCI

RLC SDURLC PCI

data 1

RLC PDU SDU 1

2‐ConcatenationIf the contents of an RLC SDU do not fill RLC PDUSo I can concatenate in the PDU and use the headers PCI to know the blocks

SDU 2

RLC Protocols(Cont’d)RLC Functions

RLC

3‐PaddingData to be transmitted does not fill RLC SDU of given size, The remainder of the data field is filled with padding bits.

RLC SDURLC PCI

data 1

RLC PDU SDU 1Dummy bits

4‐Transfer of user dataRLC supports data transfer in the below modes

oAcknowledged ModeoUnacknowledged ModeoTransparent Mode

User dataRLC

RLC PDU



PayloadRLC PCI

Buffer

Buffer

Buffer

I have to put the data in buffer and Release it once I get ACK If get NACK I retransmit the data in the buffer


RLC

•Acknowledged Mode (AM)Some data go through and get changed if Error happened Retransmission is requested (interactive PS data)

•Unacknowledged Mode (UM) Some data to through and get changed but no retransmissions happened (Streaming )

User dataRLC



•Transparent Mode (TM).•Some data go through and no change happened on it

oSignalingoNo change happened to it oAs I designed it by 3GPP to feet the lower layers

•CCCH•Amr Voice

RLC Protocols(Cont’d)

RLC Functions

5‐In‐sequence delivery of upper layer PDUs

User dataRLC

MAC SDU

RLC PDU

1RLC PDU

RLC PDU 2

3

RLC

MAC SDU

RLC PDU

1RLC PDU

RLC PDU 2

3

6‐Duplicate detectionEnsures that PDU is delivered only once to the upper layer.


7‐Error correctionThis function provides error correction by retransmission in the acknowledged data transfer mode.

Operate in ACK mode

8‐Flow controlKeep the data in buffer until the resources are ready (Control the rate of transmission)

MAC(Medium Access control Protocol) Protocols

MAC –C

MAC(Medium Access control Protocol) Protocols

Take data from RLC layer and put them on the Right transport channel

Layer 2

RLC

MAC

Logical Channels

Transport Channels

MAC ‐D

MAC ‐hsMAC ‐e

CCCHBCCHPCCH

RACHFACHPCH

DTCHDCCH

DCH

MAC Architecture UE Side

HS ‐DSCHE‐DCH

Physical Layer

Channel Coding

Multiplexing

Mapping to physical channels

Spreading

Modulation

Air interface

Transport channels

Physical Layer Overview

Mapped to combination ofoCarrier frequencyoCodeoRelative phase (UL only)

GENERAL PROTOCOL MODEL FOR WCDMA RAN INTERFACES (IUB, IUR, IU)


HORIZONTAL LAYERS

VERTICAL PLANES

Radio Network Layer(RNL)RAN related issues

Transport Network Layer(TNL)Transport technology

Control Plane User Plane

Control Plane oApplication Protocol

Iu interface Radio Access Network Application Part (RANAP)Iur Interface Radio Network Subsystems Application Part (RNSAP) Iub interface Node B Application Part (NBAP)

oSignaling Bearer for transporting the Application Protocol messages

ApplicationProtocol

SignalingBearer

Data Stream

Data Bearer

User PlaneoUser data, such as the coded voice in a voice call or the packets in an Internet connection are transported via the User Plane. oThe User Plane includes the Data Stream(s) and the Data Bearer(s) for the Data Stream(s).

TN User Plane TN User Plane

Transport Network Control Plane

ALCAP protocol (Access Link Control Application Protocol)oALCAP has its own Signaling Bearer(s) needed for the ALCAP protocol(s).

oALCAP used to set up and release the Data bearers

(In the control plan)First there is a signaling transaction by the Application Protocol

This signaling transaction triggers the set up of the Data Bearer by the ALCAP protocol



ApplicationProtocol

SignalingBearer

Data Stream

Data Bearer

Transport NetworkControl Plane

ALCAP

Signaling Bearer

VERTICAL PLANES


ApplicationProtocol

SignalingBearer

Data Stream

Data Bearer


ALCAP

Signaling Bearer

Physical Layer

GENERAL PROTOCOL MODEL FOR WCDMA RAN INTERFACES (IUB, IUR, IU) (cont’d)

RNL

TNL

HORIZONTAL LAYERS

IUB INTERFACE PROTOCOLS

RNC

Node‐B

IuB Protocols

RNL

IUB INTERFACE PROTOCOLS

oIub interfaces the RBS to the RNC


NBAP

NBAP‐DNBAP‐C

DC

H FP

RA

CH

FP

HS_D

SCH

FP

PC

H FP

Node B Application Part (NBAP)oEstablishment of a signaling connection over Iub. oIt is divided into two essential components

NBAP‐CNBAP‐D

oNBAP‐CSignaling that is not related to a specific UE.

oNBAP‐D Used for signaling relating to a specific UE context.

User plane Iub Frame Protocols (FP) oThese are DCH‐FP, RACH‐FP, FACH‐FP, HSDSCH FP and PCH‐FP transport channel

TNL defines procedures for establishing physical connections between the RBS and the RNC.

RNL

TNL



NBAP

NBAP‐DNBAP‐C

ALCAP

UNI‐SAAL

UNI‐SAAL

DC

H FP

RA

CH

FP

RA

CH

FP

PC

H FP

AAL2

ATM

oUNI‐SAAL user to network signaling ATM Adaption Layer oALCAP Access Link control Application PartoAAL2 ATM adaption layer Type 2

IUB INTERFACE PROTOCOLS(Cont’d)

IUR INTERFACE PROTOCOLS

RNC

RNC

IUR Protocols

IUR INTERFACE PROTOCOLS

oIUR interface connects two RNCs. Radio Network Layer (RNL)

RNLControl Plane User Plane

RNSAP DCH FP

oThe RNSAP protocoloThe RNSAP protocol is the signaling protocol defined for the Iur interface. oIt consists of four distinct functions:

Basic Inter‐RNC mobility support (to allow signaling between RNCs)Dedicated channel traffic support (to allow dedicated channels for user data between RNCs, e.g. for soft handover)Common channel traffic support (to allow common channel communication between RNCs). Not supported by Ericsson.Global resource management support (allows transfer of Node B timing info and cell measurements between RNCs)

oThe User Plane for the RNL across the Iur can be based either:common channel (not supported by Ericsson) dedicated channel.

TNLTN User Plane TN User Plane

SCCP

SCCP (Signaling Connection Control Protocol )Provides the functionality to transport signaling messagesMTP‐3b (Message Transfer Part layer 3)provides message routing (for point‐to‐point link) To adapt the SS7 signaling not that the SS7 signaling is not used in IUB NNI‐SAALAdapts the upper layer protocol to the requirements of the Lower ATM


MTP3b

NNI‐SAAL

AAL2

NNI‐SAAL

IUR INTERFACE PROTOCOLS (Cont’d)

ALCAP

RNLControl Plane User Plane

RNSAP DCH FP

RNL


RNSAP DCH FP

TNLTN User Plane TN User Plane

SCCP


MTP3b

NNI‐SAALAAL2

NNI‐SAAL

ATM

ALCAP

IUR INTERFACE PROTOCOLS (Cont’d)

IU INTERFACE PROTOCOLS

RNC

CN

Iu Protocols

oThe Iu interface connects the RNC to CNIu‐CS interfaces the RNC to the MSC‐serverIu‐PS interfaces the RNC to the SGSN

RNL


Data

Control plane protocol (RANAP)Provides the signaling service between UTRAN and CN

RAB managementTransport of NAS signaling messages

User Plane protocolsdata

RANAP

Radio Network Layer (RNL)

IU INTERFACE PROTOCOLS (Cont’d)

Control PlaneUser Plane

RANAP Data

TN User Plane

SCCP


MTP3b

NNI‐SAAL

AAL2

NNI‐SAAL

ATM

ALCAP

TN User Plane

Control PlaneUser Plane

RANAP Data

TN User Plane

SCCP


MTP3b

NNI‐SAAL

TN User Plane

GTP‐U

UDP

IP

AAL5

ATM

Iu‐CS Interface Protocols.

Iu‐PS Interface Protocols.

Iu‐PS interface has instead of AAL2 plane: GTP‐U (GPRS Tunneling Protocol‐User) (UDP) User Datagram Protocol Internet Protocol (IP)

GTP‐U: GTP‐U is user data bearer towards the PS domain.

UDP Transport of IP applications

Thanks You

3g protocals and proccedures

Documents