1
WCDMA RAN Interface and Procedure
2
Course ContentsCourse Contents
Chapter 1 UTRAN Network ArchitectureUTRAN Network Architecture
Chapter 2 UTRAN Interface Protocol and FunctionsUTRAN Interface Protocol and Functions
Chapter 3 Basic Signaling Process
3
UMTS System Architecture
Iu
UTRAN
UE
Uu
UTRAN : UMTS Terrestrial Radio Access NetworkCN : Core NetworkUE : User Equipment
CN
4
UTRAN System Architecture
RNS
RNC
RNS
RNC
Core Network
Node B Node B Node B Node B
Iu Iu
Iur
Iub IubIub Iub
5
Common Protocol Model of UTRAN Interfaces
ApplicationProtocol
DataStream(s)
ALCAP(s)
TransportNetwork
Layer
Physical Layer
SignallingBearer(s)
TransportUser
NetworkPlane
Control Plane User Plane
TransportUser
NetworkPlane
Transport NetworkControl Plane
RadioNetwork
Layer
SignallingBearer(s)
DataBearer(s)
The principle of interface protocol architecture is the logical mutual-independence between layers and planes. Protocol layers of a specified protocol version, or even all layers in a plane can be modified if required in the future.
6
Basic NotionsBasic Notions
UE Working Mode and State
Serving RNC 、 Drift RNC and Control RNC
Source RNC and Target RNC
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UE Working Modes and states UE Working Modes and states
Idle Mode
In standby state with no service conducted
No connection to UTRAN
There is no information related to this UE in UTRAN
Connected Mode (Cell-DCH, Cell-FACH, Cell-PCH, URA-
PCH)
Cell-DCH
In active state
Communicating via its dedicated channels
UTRAN knows which cell UE is in.
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Cell-FACH and Cell-PCH State Cell-FACH and Cell-PCH State
Cell-FACH
In active state
Few data to be transmitted both in uplink and in downlink. There is no
need to allocate dedicated channel for this UE.
Downlink uses FACH and uplink uses RACH.
UE need to monitor the FACH for its relative information.
UTRAN knows which cell UE is in.
Cell-PCH
No data to be transmitted or received.
Monitor PICH, to receive its paging.
lower the power consumption of UE.
UTRAN knows which cell UE is in.
UTRAN have to update cell information of UE when UE roams to
another cell
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URA-PCH StateURA-PCH State
URA-PCH
No data to be transmitted or received.
Monitor PICH. to enter the non-consecutive state.
UTRAN only knows which URA (UTRAN Registration Area,
which consists of multiple cells) that UE is in.
UTRAN update UE information only after UE has roamed to
other URA.
A better way to lower the resource occupancy and signaling
transmission
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UE states
CELL_DCH CELL_FACH
CELL_PCHURA_PCH
IDLE
DEAD - Scanning networks (PLMN)- ”Camp on” cell
- Monitor paging channel- cell re-selection
- Dedicated Channel- Radio bearers Transmission Services - upper layer Signaling
trigger (CN)
- Reduce action , DTX , and save power
RRC connection
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SRNC/DRNCSRNC/DRNC
In WCDMA system , notion of SRNC/DRNC is introduced because the
existence of Iur Interface
SRNC and DRNC are related to a specific UE. They can be regarded as l
ogical notions
In brief, the RNC directly connected to CN and controlling all the UE’s res
ources is called SRNC(serving RNC) of this UE
The RNC with no connection to CN but only providing resources for UE is
called DRNC(Drift RNC) of this UE
A UE in connection state has at least and only one SRNC, but can has 0
or multiple DRNCs
CN
SRNC DRNCIu
Iur
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CRNCCRNC
CRNC is related to a specific NodeB (or Cell)
The RNC connected directly to a NodeB and controlling the usage of
its resources is called the CRNC of this NodeB
There is and only one Controlling RNC for any NodeB
CRNC is in charge of the allocation and usage of NodeB’s resources
CRNC
Iub
Node BCell Cell Cell
Node B
...
CN
Iu
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Source RNC/Target RNCSource RNC/Target RNC
SRNC Relocation is the process of switching the SRNC of a specifi
c UE.
Source RNC is the SRNC before SRNC Relocation and Target RN
C is the SRNC after SRNC Relocation
Source RNC and Target RNC refer to different RNCs during a SR
NC Relocation process
CNCN
Source RNC
TargetRNC
ServingRNC
Iu IuIur RNC
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Course ContentsCourse Contents
Chapter 1 UTRAN Network Architecture
Chapter 2 UTRAN Interface Protocol and Functions
Chapter 3 Basic Signaling Process
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UTRAN Interface Protocols and FunctionsUTRAN Interface Protocols and Functions
Iu Interface
Iur Interface
Iub Interface
Uu Interface
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Iu Interface System Structure
Core Network (CN)UTRAN
Node B
Node B
Node B
Node B
RNC
Iu Interface
Iu-CS
CSDomain
PSDomain
Iu-PS
RNC
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Iu-CS Interface Protocol Stack Structure
Q.2150.1
Q.2630.1
RANAP Iu UP ProtocolLayer
TransportNetwork
Layer
Physical Layer
TransportUser
NetworkPlane
Control Plane User Plane
TransportUser
NetworkPlane
Transport NetworkControl Plane
RadioNetwork
Layer
ATM
SSCOP
AAL5
SSCOP
SSCF-NNI
AAL2AAL5
MTP3bMTP3b
SCCP
SSCF-NNI
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Iu-PS Interface Protocol Stack Structure
SSCF-NNI
SSCOP
AAL5
IP
SCTP
SCCP
SSCF-NNI
MTP3-BM3UA
RANAPIu UP Protocol
Layer
TransportNetwork
Layer
Physical Layer
TransportUser
NetworkPlane
Control Plane User Plane
TransportUser
NetworkPlane
Transport NetworkControl Plane
RadioNetwork
Layer
ATM
AAL5
IP
UDP
GTP-U
Physical Layer
ATM
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Iu Interface Functions(1)Iu Interface Functions(1)
Mobility Management
Location Area Report
SRNS Relocation
Hard handover between RNCs and inter-system handover
Radio Access Bearer ( RAB ) Management
Establishment, Modification and Release of RAB
Iu data transmission
normal data transmission
abnormal data transmission
Transparent transmission of UE-CN connection information
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Iu Interface Functions(2)Iu Interface Functions(2)
Paging
Iu Release
Security Mode Control
Overload Control
Common UE ID ( IMSI ) Management
Iu Signaling Trace Management
Iu Interface Abnormality Management
CBS(Cell Broadcast Service) Control
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UTRAN Interfaces Protocols and Functions
Iu Interface
Iur Interface
Iub Interface
Uu Interface
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Iur Interface Protocol Stack Structure
SSCF-NNI
SSCOP
MTP3-B
AAL5
IP
SCTP
SCCP
AAL5
SSCF-NNI
STC (Q.2150.1)
RNSAP Iur DataStream(s)
TransportNetwork
Layer
Physical Layer
TransportUser
NetworkPlane
Control Plane User Plane
TransportUser
NetworkPlane
Transport NetworkControl Plane
RadioNetwork
Layer
ATM
ALCAP(Q.2630.1)
AAL2
SSCF-NNI
SSCOP
MTP3-B
IP
SCTPSSCF-NNI
M3UA M3UA
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Iur Interface Functions(1)Iur Interface Functions(1)
Support Basic Mobility Functions between RNCs
Support SRNC relocation
Cell Update and URA Update between RNCs
Paging between RNCs
Protocol Error Report
Dedicated Channel Functions
Establish, Modify or Release Dedicated Channels in DRNC
during handover
Transmission of DCH TB(Transmission Block) on Iur
Management of RL(Radio Link) in DRNS by Dedicated
Measurement Procedure and Filter Control
RL Management , Compressed Mode Management
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Iur Interface Functions(2)Iur Interface Functions(2)
Common Channel Functions
Establishment, Deletion of Common transport Channels on Iur
Common Transport Channels are used to Transmit UE informati
on which is in Common Channel state in DRNC
Separate MAC-d From MAC-c
Traffic Control Between MAC-d and MAC-c
Global Resource Management
Common Measurement Between RNCs
Transmission of Node B Timing Information between RNCs
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UTRAN Interfaces Protocols and FunctionsUTRAN Interfaces Protocols and Functions
Iu Interface
Iur Interface
Iub Interface
Uu Interface
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Iub Interface Protocol Stack
Node BApplication Part
(NBAP)
AAL Type 2
ALCAP
TransportLayer
Physical Layer
RadioNetworkLayer
Radio NetworkControl Plane
TransportNetwork
Control Plane
DC
H F
P
RA
CH
FP
ATM
DS
CH
FP
AAL Type 5
User Plane
SSCF-UNI
SSCOP
AAL Type 5
SSCF-UNI
SSCOP
Q.2630.1
Q.2150.2
FA
CH
FP
PC
H F
P
US
CH
FP
CP
CH
FP
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Iub Interface Functions(1)Iub Interface Functions(1)
Common Functions
Common Transport Channel Management
Iub Common Channel Data Transmission
Logical O&M of Node B ( maintenance functions such as cell
configuration Management , Fault Management , Block
Management, etc. ) System Information Management
Common Measurement
Resource Verification
Abnormality Management
Timing and Synchronization Management
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Iub Interface Functions(2)Iub Interface Functions(2)
Dedicated Functions
Dedicated Transport Channel Management
Radio Link(RL) Monitoring
Dedicated Measurement Management
Timing and Synchronization Management
Up-link outer loop Power Control
Iub Dedicated Data transmission
Balance on down-link power drifting
Compressed Mode Control
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UTRAN Interfaces Protocols and FunctionsUTRAN Interfaces Protocols and Functions
Iu Interface
Iur Interface
Iub Interface
Uu Interface
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Uu Interface Protocol Stack Structure
L3
co
ntr
ol
co
ntr
ol
co
ntr
ol
co
ntr
ol
LogicalChannels
TransportChannels
C-plane signalling U-plane information
PHY
L2/MAC
L1
RLC
DCNtGC
L2/RLC
MAC
RLCRLC
RLCRLC
RLCRLC
RLC
Duplication avoidance
UuS boundary
BMC L2/BMC
RRC
control
PDCPPDCP L2/PDCP
DCNtGC
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Uu Interface L1 Functions(1)Uu Interface L1 Functions(1)
Multiplexing of transport channels and de-multiplexing of encoded
composite channels
Mapping of encoded composite transport channels on physical
channels
Macro-diversity distribution/combining and soft handover execution
Error detection on transport channels and indication to higher layers
FEC encoding/decoding and interleaving/de-interleaving of transport
channels
Rate matching of coded transport channels to physical channels
Power weighting and combining of physical channels
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Uu Interface L1 Functions(2)Uu Interface L1 Functions(2)
closed-loop power control
open-loop power control
Modulation and spreading/demodulation and de-spreading of
physical channels
Synchronization between frequency and time (chip, bit, slot, frame)
Radio characters measurements (FER, SIR, Interference power) and
indication to higher layers
Compressed mode support
Diversity of Transmission/Receiving
Other base band processing functions
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MAC: Medium Access Control
AS
L2
GC Nt DC
RRC(L3)
RLC
PHY(L1)
PDCP BMC
MAC
Logical Channels
Transport Channels
Control SAP's
Control SAP
Radio (Access) Bearers
Physical Channels
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MAC FunctionsMAC Functions
mapping between logical channels and transport channels
selection of appropriate Transport Format for each Transport Channel de
pending on instantaneous data rate
priority handling between data flows of one UE
priority handling between UEs by dynamic scheduling
identification of UEs on common transport channels
multiplexing/demultiplexing of higher layer PDUs into/from transport bloc
k sets delivered to/from the physical layer on common and dedicated tra
nsport channels
traffic volume monitoring
Dynamic Transport Channel type switching
ciphering for transparent RLC
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MAC: Mapping of Logical Channels(UE)
{XOR}
Transport Channels
(L1 Characteristics Dependent)
PCH BCH FACH RACH DCH
S-CCPCHP-CCPCHPhysical
ChannelsPRACH DPDCH
Logical Channels
(Data Dependent)
PCCH
DCCH
DTCH
DecicatedLogical
Channel
CipherOn
BCCH CCCH CTCH
Higher Layer data
PagingPagingSystem
InfoSystem
InfoSignalingSignaling
CellBroadcast
Service
CellBroadcast
Service
Signalingand
User data
Signalingand
User data
DTCHDTCH
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MAC: Transport Format Selection(1)
Control immediate bit rate by means of changing traffic per TTI(Transmission Time Interval, is multiple of 10ms)
Transport Block (TB): The basic unit exchanged between L1 and MAC Transport Block Size: the number of bits in a Transport Block Transport Block Set: A set of TBs transmitted in a TTI Transport Block Set Size: the number of bits in a Transport Block Set
Transport Block, TB#1
TB#2
TB#n
Transport Block Size
Transport Block Set
Transport Block Set Size = Transport Block Size x N
Transport Time Interval, TTI t
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MAC: Transport Formation Selection(2)MAC: Transport Formation Selection(2)
Transport Format (TF) defines Transport Block Set (Transport Block Size,
Transport Block Set Size,TTI,FEC type,size of CRC)
Transport Format Set (TFS): Possible TF combinations of a transport channel.
MAC will chose a TF during every TTI
Transport Format Combination (TFC): Determined TF combination in each TTI,
each transport channel
Transport Format Combination Set (TFCS): define all possible TFC combination
method. Thus MAC can process dynamic transport rate control in different
transport channels
TFCS
TrCH#1
TFS
TF
TrCH#2TrCH#3TrCH#4
TFC
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RLC: Radio Link Control
AS
L2
GC Nt DC
RRC(L3)
RLC
PHY(L1)
PDCP BMC
MAC
Control SAP's
Control SAP
Radio (Access) Bearers
Logical
Channels
Transport Channels
PhysicalChannels
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RLC FunctionsRLC Functions
Segmentation, reassembly and Padding
Transmission of user data
Error correction using different transport Format
In-sequence delivery of higher layer PDUs, duplicate
detection
Flow control
Sequence number check in Unacknowledged
Mode ( UM ) Protocol error detection and recovery
Ciphering
Suspend/resume function
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PDCP: Packet Data Convergence ProtocolBMC: Broadcast/Multicast Control
AS
L2
GC Nt DC
RRC(L3)
RLC
PHY(L1)
PDCP BMC
MAC
Control SAP's
Control SAP
Radio (Access) Bearers
Logical
Channels
Transport Channels
PhysicalChannels
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PDCP FunctionsPDCP Functions
Mapping of network PDU from network protocol to RLC
protocol entity.
header compression and de-compression in order to
reduce the redundant control information in higher layer
data, thus enhance the transport efficiency in air interface
buffering and retransmit of higher layer data
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BMC FunctionsBMC Functions
Storage of cell broadcast message
Monitoring of traffic volume and CBS (Cell Broadcast
Service) radio resource request
BMC message dispatching
Transport BMC message to UE
Transport BMC message to higher layer
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RRC: Radio Resource Control
AS
L2
GC Nt DC
RRC(L3)
RLC
PHY(L1)
PDCP BMC
MAC
Control SAP's
Control SAP
Radio (Access) Bearers
Logical
Channels
Transport Channels
PhysicalChannel
s
44
RRC Functions(1)RRC Functions(1)
Management of system information broadcast
Paging/Notification
RRC connection management ( establish 、 reconfig, maintai
n and release )Radio Bearer (RB) Management ( establish, reconfig and rele
ase ) , support NAS services
RRC connection mobility management
initial cell selection
Routing of higher layer PDUs
Control of requested QoS and map into different resources of A
ccess Stratum
Management and control of radio resources
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RRC Functions(2)RRC Functions(2)
Management and control of RB, transport channel and
physical channel
open loop power control
Support of SRNS relocation
Control of UE measurement and measurement report
Ciphering control, protection of integrity
CBS related functions ( BMC configuration , CBS radio
resource distribute request, support of CBS non-continuous
receiving )
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Course ContentsCourse Contents
Chapter 1 UTRAN Network ArchitectureChapter 1 UTRAN Network Architecture
Chapter 2 UTRAN Interface Protocol and FunctionsUTRAN Interface Protocol and Functions
Chapter 3 Basic Signaling ProcessChapter 3 Basic Signaling Process
47
Basic Signaling Procedures
Call overall process
Network start process
UE registration process
Call process, soft handover and hard handover
process
Connection mobility management process
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Call overall ProceduresNetwork side Start
1、 Initialize equipment2、 Process system
broadcast
Step 1Handset Power on
1、 cell reselection2、 Location registration
3、Waiting for call
Step 2Paging UE
Step 3
RRC connection
Establish
Step 4
NAS signaling
connection establish
Step 5RAB set up
1、 synchronous set up2、 asynchronous set up
Step 6RAB/RB modification
Step 6Transport channel
reconfiguration
Step 6Physical channel
reconfiguration
Step 6Soft/hard handover
Step 6URA update
Step 6Cell update
Step 6Handover with GSM
Step 7RRC connection
release
Step 8Waiting for call again
1、 cell selection2、 wait for call
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Basic Signaling Process
Call overall process
Network start process
UE registration process
Call process, soft handover and hard handover
process
Connection mobility management process
50
System Information Broadcast Flow
. 3.BCCH:System Information
1.System Information Update Request
UE Node B RNC CN
NBAPNBAP
RRCRRC
. 4.BCCH:System Information RRCRRC
5.BCCH:System Information RRCRRC
. 2.System Information Update Response
NBAPNBAP
51
Basic Signaling Process
Call overall process
Network start process
UE registration process
Call process, soft handover and hard handover
process
Connection mobility management process
52
RRC Connection Establishment Flow(CCH)
UE SRNC
RRC: RRC CONNECTION REQUEST
RRC: RRC CONNECTION SETUP
RRC: RRC CONNECTION SETUP COMPLETE
NodeB
UE originate RRC connection setup for registration.SRNC decides to establish RRC connection on common channel,and uses pre-configured common channel resources.
53
NAS Signaling Establishment Flow
UE SRNC CN
RRC£ ºINITIAL DIRECT TRANSFER
RANAP: INITIAL UE MESSAGE
RRC£ ºDTRANAP£ ºDT
RANAP£ ºDT
RRC£ ºDT
UE changes DT messages with CN, such as Authentication, connection establishment, location registration, etc.
54
RRC Connection Release Flow(CCH)
UE NodeB SRNC
IU RELEASE COMMAND
IU RELEASE COMPLETE
RRC£ ºRRC CONNECTION RELEASE
RRC£ ºRRC CONNECTION RELEASE COMPLETE
CN
In registration process, UE does not use dedicated user plane resources. Instead, it release signaling link directly. Thus registration procedure ends.
55
Basic Call ProcessesBasic Call Processes
Call overall process
Network start process
UE registration process
Call process, soft handover and hard handover
process
Connection mobility management process
56
Paging Flow (UE in Idle State or PCH State)
CNSRNCUE
RANAP£ ºPAGING
RRC£ ºPAGING TYPE 1
CN sends paging message and specifies UE and paging area. ( CN is responsible for paging message re-send ) . SRNC sends relevant paging message according to UE state.
57
Paging Flow (connection mode)
CN sends paging message and specifies UE and paging area. ( CN is responsible for paging message re-send ) . SRNC sends relevant paging message according to UE state.
UE ServingRNC
CN
RRCRRC2. DCCH : Paging
RANAP RANAP1. Paging
58
RRC Connection Establishment Flow(DCH)
UE SRNC
RRC: RRC CONNECTION REQUEST
RRC: RRC CONNECTION SETUP
RRC: RRC CONNECTION SETUP COMPLETE
NodeB
RL SESETUP REQUEST
RL SETUP RESPONSE
ALCAP Establish, synchronization
UE send RRC connect request containing UE identify, ability, cause on CCCH. If the condition is met, SRNC will configure NodeB according to the requirement, and establish its path to Node B, then send RRC connection setup message on CCCH channel, and wait for response from UE on DCCH.
59
NAS Signaling Establish Flow
UE SRNC CN
RRC£ ºINITIAL DIRECT TRANSFER
RANAP: INITIAL UE MESSAGE
RRC£ ºDTRANAP£ ºDT
RANAP£ ºDT
RRC£ ºDT
UE exchange DT messages with CN, such as authentication,service request, connection establish, etc.
60
RAB Establish Flow(DCH-DCH, synchronous)
UE SRNCNodeB CN
RAB ASSIGNMENT REQUEST
ALCAP Establish
RL RECONFIG PRE
RL RECONFIG READY
ALCAP Establish, synchronization
RRC : RB SETUP
RRC : RB SETUP COMPLETERAB ASSIGNMENT RESPONSE
RL RECONFIG COMMIT
There are more than one ALCAP establish procedures on Iu Interface, more than one user plane RABs can be established simultaneously. After user plane establish, UE enters call connection.
61
RAB Establish Flow(DCH-DCH, asynchronous)
UE SRNCNodeB CNRAB ASSIGNMENT REQUEST
ALCAP EstablishRL RECONFIG REQ
RL RECONFIG RESP
ALCAP Establish, synchronization
RRC : RB SETUP
RRC : RB SETUP COMPLETE
RAB ASSIGNMENT RESPONSE
62
RAB Establish Flow(RA/FA-RA/FA)
UE SRNCNodeB CNRANAP: RAB ASSIGNMENT REQUEST
ALCAP Establish
RRC : RB SETUP
RRC : RB SETUP COMPLETE
RANAP : RAB ASSIGNMENT RESPONSE
63
RAB Establish Flow(RA/FA-DCH)
RANAP: RAB ASSIGNMENT REQUEST
ALCAP Establish
RRC : RB SETUP
RRC : RB SETUP COMPLETE
RANAP : RAB ASSIGNMENT RESPONSE
RL SETUP REQ
RL SETUP RESP
ALCAP Establish, synchronization
64
RAB Reconfig Flow
UE NodeB SRNC
RL RECONFIG PREPARE
RL RECONFIG READY
RL RECONFIG COMMIT
RB RECONFIG
RB RECONFIG COMPLETE
ALCAP Establish, synchronization
ALCAP Release
CN
RAB ASSIGNMENT REQ
ALCAP Establish
RAB ASSIGNMENT RESP
ALCAP Release
65
Transport Channel Reconfig Flow
UE NodeB SRNC
RL RECONFIG PREPARE
RL RECONFIG READY
RL RECONFIG COMMIT
TRANSPORT CHANNEL RECONFIG
TRANSPORT CHANNEL RECONFIG COMPLETE
ALCAP Establish, synchronization
ALCAP Release
66
Physical Channel Reconfig Flow
UE NodeB SRNC
RL RECONFIG PREPARE
RL RECONFIG READY
RL RECONFIG COMMIT
PHYSICAL CHANNEL RECONFIG
PHYSICAL CHANNEL RECONFIG COMPLETE
67
Notions Related to Soft HandoverNotions Related to Soft Handover
Soft Handover
Macro diversity is a operation state in which a User
Equipment simultaneously has radio links with two or more
UTRAN access points. The aim is to improve quality of the
radio connection or provide seamless connection.
Active Set is a set of radio links simultaneously involved in a
specific communication service between an UE and a
UTRAN access point.
68
Soft Handover Illustration (Intra RNC)
Before Soft Handover After Soft Handover
CN
SRNC
NodeBNodeB
CN
SRNC
NodeBNodeB
CN
SRNC
NodeBNodeB
During Soft Handover
69
Soft Handover Flow (Intra RNC add branch)
Decision to setupnew RL
7. DCCH : Active Set Update Complete
6.DCCH: Active Set Update Command
UE Node B(new) SRNC
NBAP1. Radio Link Setup RequestNBAP
NBAP2. Radio Link Setup ResponseNBAP
3 ALCAP Iub Data Transport Bearer Setup
Start RX description
DCH-FP4. Downlink SynchronizationDCH-FP
DCH-FP5.Uplink SynchronizationDCH-FP
Start RX description
RRC
RRC
RRC
RRC
70
Soft Handover Flow (Intra-RNC delete branch)
Decision to deletea RL
2. DCCH : Active Set Update Complete
1.DCCH: Active Set Update Command
UE Node B(old) SRNC
NBAP3. Radio Link Deletion RequestNBAP
NBAP4. Radio Link Deletion ResponseNBAP
RRC
RRC
RRC
RRC
Stop RX and Tx
5 ALCAP Iub Transport Bearer release
71
Soft Handover Illustration (Inter-RNC)
Before Soft Handover After Soft Handover
Radio Link(RL) is added and deleted simultaneously
CN
SRNC RNC
NodeB NodeBNodeB
CN
SRNC RNC
NodeB NodeBNodeB
72
Soft Handover Flow (Inter-RNC)
7. Uplink Synchronization
RNSAP RNSAP
1. Radio Link Setup Request
Start TX description
RNSAP RNSAP
4. Radio Link SetupResponse
NBAP NBAP2. Radio Link Setup Request
NBAP NBAP3. Radio Link Setup Response
Start RX description
Decision to setupnew RL and
release old RL
NBAP 10. Radio Link Deletion Request
NBAP NBAP11. Radio Link Release Response
Stop RX and TX
12. ALCAP Iub Data Transport Bearer Release
RRCRRC9. DCCH : Active Set Update Complete
RRCRRC 8. DCCH: Active Set Update Command
[Radio Link Addition & Deletion]
NBAP
UE Node BDrift RNS
Node BServing RNS
Drift RNC Serving RNC
ALCAP Iur Bearer Setup5. ALCAP Iub Data Transport Bearer Setup
DCH-FPDCH-FP
DCH-FPDCH-FP
6. Downlink Synchronization
73
Hard Handover Illustration (Intra-RNC)
Before Har Handover 7 After Hard Handover
Radio Link(RL)cannot exist simultaneously
CN
SRNC
NodeBNodeB
CN
SRNC
NodeBNodeB
74
Hard Handover Flow (Intra-RNC)
UE Node B Source Node B Target SRNC
8. DCCH : Physical Channel Reconfiguration Complete
6.DCCH : Physical Channel Reconfiguration
1. Radio Link Setup Request
2. Radio Link Setup Response
9. Radio Link Deletion Request
10. Radio Link Deletion Response
3 ALCAP ub Data Transport Bearer Setup
7. Radio Link Failure IndicationRRCRRC
NBAPNBAP
NBAP
RRCRRC
NBAP
NBAP
NBAP NBAP
Decide to handover
Start Rx
Start Tx
DCH-FP4. Downlink SynchronizationDCH-FP
DCH-FP5.Uplink SynchronizationDCH-FP
NBAP
NBAP
NBAP
11. ALCAP Iub Data Transport Bearer Release
75
Hard Handover Illustration (Inter-RNC)
Before Hard Handover After Hard Handover
Radio Link(RL)can’t exist simultaneously
CN
SRNC RNC
NodeBNodeB
CN
SRNC RNC
NodeBNodeB
76
Hard Handover Flow (Inter-RNC via Iur interface)
RNSAPRNSAP1. Radio Link Setup Request
UE Node B
Source
Node BTarget
RNCSource
RNCTarget
SRNC
RRCRRC
10. DCCH : Physical Channel Reconfiguration Complete
RRC7.DCCH : Physical Channel Reconfiguration
RRC
6. ALCAP Iur Data Transport Bearer Setup
NBAP NBAP2. Radio Link Setup Request
NBAP NBAP3. Radio Link Setup Response
NBAP NBAP12. Radio Link Deletion Request
NBAP NBAP13. Radio Link Deletion Response
4. ALCAP ub Data Transport Bearer Setup
14. ALCAP Iub Data Transport Bearer Release
RNSAP RNSAP15. Radio Link Deletion Response
16. ALCAP Iur Data Transport Bearer Release
RNSAP5. RL Setup Response
RNSAP
RNSAP11. Radio Link Deletion Request
RNSAP
NBAP NBAP8. Radio Link Failure Indication
RNSAPRNSAP
9. Radio Link Failure Indication
77
RRC Release Flow( DCH)
UE NodeB SRNC CN
IU RELEASE COMMAND
IU RELEASE COMPLETE
ALCAP ReleaseRRC : RRC CONNECTION RELEASE
RRC : RRC CONNECTION RELEASE COMPLETE
RL DELETION
RL DELETION RESPONSE
ALCAP Release
Release procedure is usually originated by CN. But if UE is faulty, SRNC can also request release. Connection to UE is released first, then the connection to Node B. The release of RRCis the end of call.
78
Basic Signaling Process
Call overall process
Network start process
UE registration process
Call process, soft handover and hard handover
process
Connection mobility management process
79
Connection mobility management processes
Cell update process
URA update process
Inter-system handover process
80
Forward Handover
Forward Handover, including CELL UPDATE and URA UPDATE, is
originated by UE. URA UPDATE procedure is only used for UE under
URA_PCH state to process URA reselection, and to check if RRC
connection is right.
For UE under CELL_FACH and CELL_PCH state
cell reselection needed
In specific SA(Service Area) , Timer T305 timed out (this timer is defined in
system broadcast message)
For UE under CELL_PCH and URA_PCH state
transfer data on up link needed (enter CELL_FACH state)
upon receiving paging message on PCCH, originate cell update
CELL UPDATE process can be used to re-establish unrecoverable errors of
RLC entity ( losing connection ) , and to monitor RRC connection state.
81
Cell Update Flow
UE DRNCSource
DRNCTarget
SRNC
RNSAP RNSAP8. Common Transp. Channel Resources Release
RNSAPRNSAP
2. Uplink Signaling TransferIndication
RNSAP
3. Common Transp. Channel ResourcesInitialization Request
RNSAP
RRC1. CCCH: Cell Update
RRC-relay
RRC6. DCCH: Cell Update Confirm
RRC
RRC7. DCCH: RNTI Relocation Complete
RRC
RNSAPRNSAP
4. Common Transp. Channel Resourcesinitialization Response
5. ALCAP Iur bearer setup
82
URA Update Flow
UETargetRNC
5.CCCH: URA Update Confirm
SourceRNC
2.Uplink Signaling Transfer Indication
ServingRNC
[new C-RNTI,D-RNTI, UL message]
1.CCCH: URA Update
[U-RNTI, URA update cause]RRC-relayRRC
3. Decision Not toperform SRNS
relocation
RRC RRC-relay
RNSAP
RNSAP
4. Downlink Signaling Transfer Request
RNSAP
RNSAP
83
Hard Handover Flow( UMTS->GSM)
MAP/E MAP/E
2. PrepareHandover
BSSMAP BSSMAP4. Handover Request Ack
RANAP RANAP
13. Iu ReleaseComplete
BSSMAP BSSMAP
3. Handover Request
MAP/E MAP/E5. Prepare Handover
Response
RANAP RANAP
6. Relocation Command
BSSMAP BSSMAP
8. Handover Detect
BSSMAP BSSMAP
10. Handover Complete
MAP/E MAP/E
11. Send End Signal Request
MAP/E MAP/E
14. Send End Signal Response
RANAP RANAP1. Relocation Required
UE Node BRNC
Serving CN MSC BSC BTS
RRC
7. DCCH : Inter-System Handover Command
RRC
RR9. Handover Complete
RR
RANAP RANAP
12. Iu Release Command
84
Hard Handover Flow( GSM->UMTS)
RANAP RANAP
3. RelocationRequest
BSSMAP BSSMAP
1. HandoverRequired
RANAP RANAP
4. RelocationRequest Ack
MAP/E MAP/E
5. Prepare HandoverResponse
MAP/E MAP/E
2. PrepareHandover
BSSMAP BSSMAP
6. HandoverCommand
MAP/E MAP/E
11. Send End SignalRequest
BSSMAP BSSMAP
12. ClearCommand
BSSMAP BSSMAP
13. ClearComplete
RANAP RANAP
10. Relocation Complete
UE Node B RNCTarget
CN MSC BSC BTS
MAP/E MAP/E
14. Send End SignalResponse
RRC9. DCCH : Handover Complete
RRC
RR
7. Handover Command
RR
RANAP RANAP
8. RelocationDetect
85
Cell Reselection Flow( UMTS->GPRS)
UE CN
2. UE Access GPRS system
ServingRNC
RANAP RANAP
4. Iu Release Command
RANAP RANAP
4. Iu Release Complete
GPRS
1. UE releases connection with RNC
3. Inter-system information exchangedata transfer
86
Cell reselection Flow( GPRS->UMTS)
UE ServingRNC
1. UE Access UMTS system(RNC)
CN
2. Make signaling connection with CN
3. User plane bearers set up
GPRS
4. Inter-system information exchangedata transfer
87