3g protocals and proccedures
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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
INTRODUCTION TO RADIO INTERFACE, Uu (Cont’d)
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
INTRODUCTION TO RADIO INTERFACE, Uu (Cont’d)
INTRODUCTION TO RADIO INTERFACE, Uu (Cont’d)
Layer 3RRC
NAS
Control Plane
Layer 2
RLC
MAC
User Plan (User data)
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
User Plan (User data)
Logical Channels
Transport Channels
PHY L1
RRC
Control Plane
RLC
MAC
User Plan (User data)
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 (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 (Radio Resource Controller) Cont’d
RRC FUNCTIONS AND PROCEDURES
1‐ BROADCAST OF SYSTEM INFORMATIONThe System Information messages are sent on BCCH logical channel
RRC (Radio Resource Controller) Cont’d
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
RRC (Radio Resource Controller) Cont’d
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)
RRC (Radio Resource Controller) 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)
2‐ INITIAL CELL SELECTION AND CELL RESELECTION (Cont’d)
RRC (Radio Resource Controller) 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
Cell reselection procedure(Cont’d)
2‐ INITIAL CELL SELECTION AND CELL RESELECTION (Cont’d)
RRC (Radio Resource Controller) Cont’d
GSM measurement
Time
Qqualmin‐18
‐14
Qqualmeas
SRAT Search=4dB
Cell reselection procedure(Cont’d)
2‐ INITIAL CELL SELECTION AND CELL RESELECTION (Cont’d)
RRC (Radio Resource Controller) Cont’d
Qqualmeas <= Sintrasearch + qQualMin
GSM measurement
Time
Qrxlevmin‐115
‐112
QRxlevmeas
sHcsRat =3dB
Cell reselection procedure(Cont’d)
2‐ INITIAL CELL SELECTION AND CELL RESELECTION (Cont’d)
RRC (Radio Resource Controller) Cont’d
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
Cell reselection procedure(Cont’d)
2‐ INITIAL CELL SELECTION AND CELL RESELECTION (Cont’d)
RRC (Radio Resource Controller) Cont’d
Time
Qmeas
R(S)
qHyst2=4
R(n)
Qmeas(S)
Qmeas(n)
qOffset2SN=o
TreSelection
Cell Re‐Selection to Neig
R(n) >R(S)
Cell reselection procedure(Cont’d)
2‐ INITIAL CELL SELECTION AND CELL RESELECTION (Cont’d)
RRC (Radio Resource Controller) Cont’d
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)
Cell reselection procedure(Cont’d)
2‐ INITIAL CELL SELECTION AND CELL RESELECTION (Cont’d)
RRC (Radio Resource Controller) Cont’d
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
RRC (Radio Resource Controller) Cont’d
Idle
RRC (Radio Resource Controller) Cont’d
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
RRC (Radio Resource Controller) Cont’d
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
RRC (Radio Resource Controller) Cont’d
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.
RRC (Radio Resource Controller) Cont’d
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.
RRC (Radio Resource Controller) Cont’d
SC
SC
SC
RANAP
Note that only one RRC Connection is used.
Signaling Connection Release
RRC (Radio Resource Controller) Cont’d
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
RRC (Radio Resource Controller) Cont’d
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
RRC (Radio Resource Controller) Cont’d
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
RNC RAB Assignment Request
RB Reconfiguration Complete
CN
RB Reconfiguration
RNC RAB Assignment Request
Radio Bearer Release Complete
CN
Radio Bearer Release
Radio Bearer Setup
Radio Bearer Reconfiguration
Radio Bearer Release
RRC (Radio Resource Controller) Cont’d
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
RRC (Radio Resource Controller) Cont’d
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
RRC (Radio Resource Controller) Cont’d
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
PayloadRLC PCIRLC 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 PCIRLC PDU
RLC PDU PayloadRLC PCI
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 Protocols(Cont’d)RLC Functions
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
PayloadRLC PCIRLC PDU
RLC PDU PayloadRLC PCI
•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.
RLC Protocols(Cont’d)RLC Functions
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)
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
GENERAL PROTOCOL MODEL FOR WCDMA RAN INTERFACES (IUB, IUR, IU)
Control Plane User Plane
ApplicationProtocol
SignalingBearer
Data Stream
Data Bearer
Transport NetworkControl Plane
ALCAP
Signaling Bearer
VERTICAL PLANES
Control Plane User Plane
ApplicationProtocol
SignalingBearer
Data Stream
Data Bearer
Transport NetworkControl Plane
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
Control Plane User Plane
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
Control Plane User Plane
Transport NetworkControl Plane
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
Transport NetworkControl Plane
MTP3b
NNI‐SAAL
AAL2
NNI‐SAAL
IUR INTERFACE PROTOCOLS (Cont’d)
ALCAP
RNLControl Plane User Plane
RNSAP DCH FP
RNL
Control Plane User Plane
RNSAP DCH FP
TNLTN User Plane TN User Plane
SCCP
Transport NetworkControl Plane
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
Control Plane User Plane
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
Transport NetworkControl Plane
MTP3b
NNI‐SAAL
AAL2
NNI‐SAAL
ATM
ALCAP
TN User Plane
Control PlaneUser Plane
RANAP Data
TN User Plane
SCCP
Transport NetworkControl Plane
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
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