7. HUAWEI UMTS Radio Access Network
Protocols and Signalling Analysis
Manual Version T2-030223-20041001-C-1.22
Product Version BSC6800V100R002 NodeB V100R003
BOM 31026523
Huawei Technologies Co., Ltd. provides customers with comprehensive technical support
and service. Please feel free to contact our local office or company headquarters.
Huawei Technologies Co., Ltd.
Address: Administration Building, Huawei Technologies Co., Ltd.,
Bantian, Longgang District, Shenzhen, P. R. China
Postal Code: 518129
Website: http://www.huawei.com
Email: support@huawei.com
9. Summary of Updates
This section provides the update history of this manual and introduces the contents of
subsequent updates.
Update History
This manual is updated for a major product version to maintain consistency with system
hardware or software versions and to incorporate customer suggestions.
Manual Version Notes
T2-030223-20041001-C-1.22 Initial commercial release
Updates of Contents
None
10. About This Manual
Release Notes
This manual applies to BSC6800 V100R002 and NodeB V100R003.
Organization
The manual analyzes protocols and signaling of radio access network in UMTS.
There are 7 chapters and 3 appendixes in the manual.
Chapter 1 UTRAN Interface Protocols and Functions profiles the interfaces,
functions and the corresponding protocols in the radio access network of UMTS. The
user planes of Iub/Iur/Iu interfaces are described in this chapter.
Chapter 2 Transport Network Layer Procedure Analysis analyzes the signalling
procedures of transport network layer and describes the functions of entities in the
transport network signalling layer.
Chapter 3 Cell Related Procedure Analysis analyzes the cell-related procedures,
such as cell setup, common channel setup and a whole cell setup procedure example
is presented.
Chapter 4 System Information Procedure Analysis analyzes the system information
procedures.
Chapter 5 Call Setup and Release Procedure Analysis mainly analyzed the
procedures of RRC connection setup and release, of RAB setup and release.
Chapter 6 Mobility Management Procedure Analysis analyzes the procedures of
forward handover, soft handover, hard handover, Inter-Rat handover and SRNS
relocation.
Chapter 7 Dynamic Resource Control Procedure Analysis analyzes the
procedures of RAB modification and dynamic channel reconfiguration.
Appendix A Tracing Tools introduce the message tracing tools.
Appendix B Call Example presents a whole typical call procedure example.
Appendix C Acronyms and Abbreviations
Intended Audience
11. The manual is intended for the following readers:
Technical marketing specialists
Operation and maintenance personnel
Conventions
The manual uses the following conventions:
I. General conventions
Convention Description
Arial Normal paragraphs are in Arial.
Arial Narrow Warnings, Cautions, Notes and Tips are in Arial Narrow.
Boldface Headings are in Boldface.
Courier New Terminal Display is in Courier New.
II. Symbols
Eye-catching symbols are also used in the manual to highlight the points worthy of
special attention during the operation. They are defined as follows:
Caution, Warning, Danger: Means reader be extremely careful during the
operation.
Note, Comment, Tip, Knowhow, Thought: Means a complementary description.
12. Protocols and Signalling Analysis
HUAWEI UMTS Radio Access Network Table of Contents
Table of Contents
Chapter 1 UTRAN Interface Protocols and Functions............................................................... 1-1
1.1 Overview ............................................................................................................................ 1-1
1.2 Uu Interface ....................................................................................................................... 1-2
1.2.1 Uu Protocol Structure.............................................................................................. 1-2
1.2.2 RRC Functions ........................................................................................................ 1-4
1.2.3 L2 Functions............................................................................................................ 1-5
1.2.4 L1 Functions............................................................................................................ 1-6
1.3 Iub interface ....................................................................................................................... 1-6
1.3.1 Iub Protocol Structure ............................................................................................. 1-6
1.3.2 Functions of NBAP.................................................................................................. 1-8
1.3.3 NBAP Procedures ................................................................................................... 1-8
1.3.4 Iub FP for Common Transport Channel Data Transfer......................................... 1-10
1.3.5 Iub FP for Dedicated Transport Channel Data Transfer ....................................... 1-14
1.4 Iur Interface...................................................................................................................... 1-18
1.4.1 Iur Protocol Structure ............................................................................................ 1-18
1.4.2 Functions of RNSAP ............................................................................................. 1-19
1.4.3 RNSAP Procedures .............................................................................................. 1-20
1.4.4 Iur FP for Transport Channel Data Transfer ......................................................... 1-22
1.5 Iu Interface ....................................................................................................................... 1-22
1.5.1 Iu Protocol Architecture......................................................................................... 1-22
1.5.2 Functions of RANAP ............................................................................................. 1-25
1.5.3 RANAP Procedures .............................................................................................. 1-26
1.5.4 Functions of Iu UP................................................................................................. 1-28
1.5.5 GTP-U ................................................................................................................... 1-33
1.5.6 Functions of SABP ................................................................................................ 1-33
Chapter 2 Transport Network Layer Procedure Analysis ......................................................... 2-1
2.1 Overview ............................................................................................................................ 2-1
2.2 SAAL.................................................................................................................................. 2-1
2.2.1 Overview ................................................................................................................. 2-1
2.2.2 SSCOP.................................................................................................................... 2-2
2.2.3 SSCF....................................................................................................................... 2-7
2.2.4 CPCS ...................................................................................................................... 2-8
2.2.5 SAR ......................................................................................................................... 2-8
2.2.6 LM ........................................................................................................................... 2-9
2.2.7 SSCOP Message .................................................................................................. 2-10
2.3 MTP3-B............................................................................................................................ 2-11
2.3.1 Overview ............................................................................................................... 2-11
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HUAWEI UMTS Radio Access Network Table of Contents
2.3.2 Function................................................................................................................. 2-12
2.3.3 Message Structure ................................................................................................ 2-14
2.3.4 Changeover/Changeback/ Management prohibit ................................................. 2-19
2.3.5 Signaling Network Management and Status of Signaling Link ............................. 2-20
2.3.6 Signaling Network Management and Signaling Route Status .............................. 2-22
2.3.7 MTP3-B Upper User Message .............................................................................. 2-23
2.3.8 MTP3-B Test Message ......................................................................................... 2-24
2.3.9 MTP3-B Management Message ........................................................................... 2-25
2.4 ALCAP ............................................................................................................................. 2-26
2.4.1 Overview ............................................................................................................... 2-26
2.4.2 Function................................................................................................................. 2-27
2.4.3 Message structure................................................................................................. 2-29
2.4.4 Establish Request Message.................................................................................. 2-30
2.5 SCCP ............................................................................................................................... 2-31
2.5.1 Overview ............................................................................................................... 2-31
2.5.2 Function................................................................................................................. 2-32
2.5.3 Message Structure ................................................................................................ 2-33
2.5.4 Connection Request Message .............................................................................. 2-34
Chapter 3 Cell Related Procedure Analysis ............................................................................... 3-1
3.1 Overview ............................................................................................................................ 3-1
3.2 Procedures Involved in Cell Setup..................................................................................... 3-1
3.2.1 Resource Status Indication Procedure ................................................................... 3-1
3.2.2 Resource Audit Procedure ...................................................................................... 3-2
3.2.3 Cell Setup Procedure .............................................................................................. 3-3
3.2.4 Common Transport Channel Setup Procedure....................................................... 3-4
3.2.5 Iub Interface User Plane Setup ............................................................................... 3-4
3.2.6 System Information Update..................................................................................... 3-5
3.2.7 Common Measurement Initiation Procedure .......................................................... 3-5
3.2.8 Cell Reconfiguration Procedure .............................................................................. 3-6
3.2.9 Cell Deletion Procedure .......................................................................................... 3-7
3.2.10 Resource Status Indication Message ................................................................... 3-7
3.2.11 Audit Response Message ................................................................................... 3-12
3.2.12 Cell Setup Request Message.............................................................................. 3-16
3.2.13 Common Transport Channel Setup Request Message ...................................... 3-20
3.2.14 System Information Update Request Message .................................................. 3-25
3.3 Example of Cell Setup Procedures.................................................................................. 3-28
Chapter 4 System Information Procedure Analysis .................................................................. 4-1
4.1 Overview ............................................................................................................................ 4-1
4.1.1 System Information Structure.................................................................................. 4-1
4.1.2 System Information Monitoring Mechanism............................................................ 4-2
4.1.3 Functions of System Information............................................................................. 4-2
4.2 System Information Broadcast and Update....................................................................... 4-3
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HUAWEI UMTS Radio Access Network Table of Contents
4.2.1 System Information Broadcast ................................................................................ 4-3
4.2.2 System Information Update..................................................................................... 4-3
4.2.3 System Information Message.................................................................................. 4-4
4.3 System Information Modification........................................................................................ 4-6
4.3.1 Modification by a value tag...................................................................................... 4-7
4.3.2 Modification by a timer ............................................................................................ 4-7
4.3.3 Paging Type 1 Message ......................................................................................... 4-7
Chapter 5 Call Setup and Release Procedure Analysis ............................................................ 5-1
5.1 Overview ............................................................................................................................ 5-1
5.2 Paging................................................................................................................................ 5-1
5.2.1 Overview ................................................................................................................. 5-1
5.2.2 Paging for UEs in Idle Mode or in PCH State ......................................................... 5-2
5.2.3 Paging for UEs in CELL_DCH or CELL_FACH State............................................. 5-3
5.2.4 Paging Type 1 Message ......................................................................................... 5-3
5.2.5 Paging Type 2 Message ......................................................................................... 5-4
5.3 RRC Connection Setup ..................................................................................................... 5-5
5.3.1 Overview ................................................................................................................. 5-5
5.3.2 RRC Connection Setup on Dedicated Channel ...................................................... 5-6
5.3.3 RRC Connection Setup on Common Channel........................................................ 5-7
5.3.4 RRC Connection Reject .......................................................................................... 5-7
5.3.5 RRC Connection Request Message ....................................................................... 5-8
5.3.6 RRC Connection Setup Message ......................................................................... 5-10
5.3.7 RRC Connection Reject Message ........................................................................ 5-13
5.3.8 Radio Link Setup Request Message..................................................................... 5-14
5.4 Direct Transfer Messages................................................................................................ 5-18
5.4.1 Overview ............................................................................................................... 5-18
5.4.2 Initial Direct Transfer ............................................................................................. 5-18
5.4.3 Uplink Direct Transfer ........................................................................................... 5-19
5.4.4 Downlink Direct Transfer....................................................................................... 5-20
5.4.5 Initial Direct Transfer Message ............................................................................. 5-21
5.4.6 Uplink Direct Transfer Message............................................................................ 5-22
5.4.7 Downlink Direct Transfer Message ....................................................................... 5-23
5.5 UE Capability Information ................................................................................................ 5-24
5.5.1 UE Capability Enquiry ........................................................................................... 5-25
5.5.2 UE Capability Information Update......................................................................... 5-25
5.6 RAB Setup ....................................................................................................................... 5-26
5.6.1 Overview ............................................................................................................... 5-26
5.6.2 DCH-DCH.............................................................................................................. 5-27
5.6.3 CCH-DCH.............................................................................................................. 5-30
5.6.4 CCH-CCH.............................................................................................................. 5-32
5.6.5 RAB Assignment Request Message ..................................................................... 5-33
5.6.6 RAB Assignment Response Message .................................................................. 5-36
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15. Protocols and Signalling Analysis
HUAWEI UMTS Radio Access Network Table of Contents
5.6.7 Radio Bearer Setup Message ............................................................................... 5-38
5.7 Call Release..................................................................................................................... 5-43
5.7.1 Overview ............................................................................................................... 5-43
5.7.2 Iu Signaling Connection Release .......................................................................... 5-44
5.7.3 RAB Release......................................................................................................... 5-45
5.7.4 Combined Release of CS Domain Iu Signaling Link and RAB ............................. 5-47
5.7.5 RRC Connection Release ..................................................................................... 5-48
Chapter 6 Mobility Management Procedure Analysis ............................................................... 6-1
6.1 Overview ............................................................................................................................ 6-1
6.2 Forward handover.............................................................................................................. 6-1
6.2.1 Overview ................................................................................................................. 6-1
6.2.2 Cell Update.............................................................................................................. 6-1
6.2.3 URA Update ............................................................................................................ 6-3
6.2.4 Cell Update Message.............................................................................................. 6-4
6.2.5 URA Update Message ............................................................................................ 6-6
6.3 Soft Handover .................................................................................................................... 6-8
6.3.1 Overview ................................................................................................................. 6-8
6.3.2 Radio Link Addition ................................................................................................. 6-9
6.3.3 Radio Link Deletion ............................................................................................... 6-10
6.3.4 Radio Link Addition and Deletion .......................................................................... 6-12
6.3.5 Radio Link Setup Request Message..................................................................... 6-13
6.3.6 Active Set Update Message.................................................................................. 6-13
6.4 Hard Handover................................................................................................................. 6-15
6.4.1 Overview ............................................................................................................... 6-15
6.4.2 Compressed Mode................................................................................................ 6-16
6.4.3 Iur Interface Hard Handover.................................................................................. 6-17
6.4.4 Combined Hard Handover .................................................................................... 6-19
6.4.5 Radio Link Setup Request Message..................................................................... 6-22
6.4.6 Physical Channel Reconfiguration Message ........................................................ 6-22
6.5 Inter-RAT Handover......................................................................................................... 6-24
6.5.1 Overview ............................................................................................................... 6-24
6.5.2 WCDMA->GSM Inter-RAT Handover ................................................................... 6-25
6.5.3 GSM->WCDMA Inter-RAT Handover ................................................................... 6-27
6.5.4 GSM/GPRS->WCDMA Cell Reselection .............................................................. 6-29
6.5.5 WCDMA->GSM/GPRS Cell Reselection .............................................................. 6-29
6.5.6 Handover from UTRAN Command Message........................................................ 6-32
6.5.7 Handover to UTRAN Command Message............................................................ 6-33
6.6 Relocation ........................................................................................................................ 6-35
6.6.1 Overview ............................................................................................................... 6-35
6.6.2 Static Relocation ................................................................................................... 6-35
6.6.3 Relocation with Hard Handover ............................................................................ 6-39
6.6.4 Relocation with Forward Handover ....................................................................... 6-41
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HUAWEI UMTS Radio Access Network Table of Contents
6.6.5 Relocation Required Message .............................................................................. 6-42
6.6.6 Relocation Request Message ............................................................................... 6-45
6.6.7 Relocation Command Message ............................................................................ 6-46
6.6.8 UTRAN Mobility Information Message.................................................................. 6-49
6.6.9 Uplink Signaling Transfer Indication Message...................................................... 6-51
Chapter 7 Dynamic Resource Control Procedure Analysis...................................................... 7-1
7.1 Overview ............................................................................................................................ 7-1
7.2 RAB Modification ............................................................................................................... 7-1
7.2.1 Overview ................................................................................................................. 7-1
7.2.2 RAB Modification (DCH-DCH) ................................................................................ 7-1
7.2.3 RAB Assignment Request Message ....................................................................... 7-3
7.2.4 Radio Bearer Reconfiguration Message ................................................................. 7-3
7.3 Dynamic Channel Reconfiguration .................................................................................... 7-6
7.3.1 Overview ................................................................................................................. 7-6
7.3.2 RB Reconfiguration ................................................................................................. 7-7
7.3.3 Radio Bearer Reconfiguration Message ................................................................. 7-8
Appendix A Tracing Tools............................................................................................................A-1
A.1 About Tracing Tools ..........................................................................................................A-1
A.1.1 RNC Tracing Tool ...................................................................................................A-1
A.1.2 NodeB Tracing Tool................................................................................................A-1
Appendix B Call Example .............................................................................................................B-1
B.1 Overview............................................................................................................................B-1
B.2 Originating Call Procedure ................................................................................................B-1
B.3 Terminated Call procedure................................................................................................B-4
Appendix C Acronyms and Abbreviations .................................................................................C-1
Index ................................................................................................................................................ i-1
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17. Protocols and Signalling Analysis Chapter 1
HUAWEI UMTS Radio Access Network UTRAN Interface Protocols and Functions
Chapter 1 UTRAN Interface Protocols and
Functions
1.1 Overview
Figure 1-1 UTRAN interfaces
As shown in Figure 1-1, UTRAN interfaces in the UMTS system include Iub, Iur, Iu and
Uu interfaces. See Table 1-1 for the description of the interfaces.
Table 1-1 UTRAN interfaces
Interface Description
Uu Logical interface between UTRAN and UE
Iub Logical interface between RNC and NodeB
Iur Logical interface between RNCs
Iu Logical interface between RNC and CN
1-1
18. Protocols and Signalling Analysis Chapter 1
HUAWEI UMTS Radio Access Network UTRAN Interface Protocols and Functions
Iub, Iur, Iu and Uu interfaces are standard interfaces and can be used to connect
different network elements (NEs) from different vendors. Iub, Iur and Iu interfaces are
also called as UTRAN terrestrial interfaces.
According to the type of CN entity connected to RNC, the Iu interface can be classified
into Iu-CS interface, Iu-PS interface and Iu-BC interface. Iu-CS interface is used to
connect RNC and MSC. Iu-PS interface is used to connect RNC and SGSN. The Iu-BC
interface is used to connect RNC and CBC.
1.2 Uu Interface
1.2.1 Uu Protocol Structure
Uu interface is the interface between User Equipment (UE) and UMTS Terrestrial Radio
Access Network (UTRAN) and it is the most important interface in the UMTS system.
As shown in Figure 1-2, Uu interface includes three protocol layers, physical layer (L1),
data link layer (L2) and network layer (L3).
L1 provides the radio physical channels for the transmission of the traffic from upper
layers. The functions of L1 are implemented by NodeB.
L2 includes four sublayers, Medium Access Control (MAC), Radio Link Control (RLC),
Broadcast/Multicast Control (BMC) and Packet Data Convergence Protocol (PDCP).
The functions of L2 are implemented by RNC.
L3 includes the RRC sublayer in the access stratum, the Mobility Management (MM)
and Call Control (CC) in the non-access stratum. The RRC functions of L3 are
implemented by RNC, and the MM and CC functions of L3 are implemented by CN.
1-2
19. Protocols and Signalling Analysis Chapter 1
HUAWEI UMTS Radio Access Network UTRAN Interface Protocols and Functions
GC Nt DC
Duplication avoidance
GC Nt DC
UuS boundary
C-plane signalling U-plane information
RRC control L3
co co co co
Radio
ntr ntr ntr ntr Bearers
PDCP
PDCP L2/PDCP
BMC
L2/BMC
RLC RLC L2/RLC
RLC RLC
RLC RLC
RLC RLC
Logical
Channels
MAC L2/MAC
Transport
Channels
PHY L1
Figure 1-2 Uu interface protocol stack
Uu interface specifications are shown in Figure 1-3.
1-3
20. Protocols and Signalling Analysis Chapter 1
HUAWEI UMTS Radio Access Network UTRAN Interface Protocols and Functions
GC Nt DC
Duplication avoidance
GC Nt DC
C-plane signalling U-plane information UuS boundary
control
L3
TS25.331
TS25.323 L2/PDCP
control
control
control
control
TS25.324 L2/BMC
RLC RLC L2/RLC
RLC RLC
RLC RLC
RLC TS25.322
Logical
Channels
TS25.321 L2/MAC
Transport
Channels
TS25.211~TS25.215 L1
Figure 1-3 Uu interface specifications
1.2.2 RRC Functions
The RRC performs the functions listed below :
Broadcast of information related to the non-access stratum (Core Network);
Broadcast of information related to the access stratum;
Establishment, maintenance and release of an RRC connection between the UE
and UTRAN;
Establishment, reconfiguration and release of Radio Bearers;
Assignment, reconfiguration and release of radio resources for the RRC
connection;
RRC connection mobility functions;
Route selection for the Protocol Data Unit (PDU) of upper layers;
Control of requested QoS;
UE measurement reporting and control of the reporting;
Outer loop power control;
Control of ciphering;
Paging;
Initial cell selection and cell re-selection;
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21. Protocols and Signalling Analysis Chapter 1
HUAWEI UMTS Radio Access Network UTRAN Interface Protocols and Functions
Arbitration of radio resources on uplink DCH;
RRC message integrity protection;
CBS control.
1.2.3 L2 Functions
L2 includes four sublayers, Medium Access Control (MAC), Radio Link Control (RLC),
Broadcast/Multicast Control (BMC) and Packet Data Convergence Protocol (PDCP).
I. MAC
The functions of MAC include:
Mapping between logical channels and transport channels
Selection of appropriate Transport Format for each Transport Channel
Priority handling between data flows of one UE
Priority handling between UEs by means of dynamic scheduling
Priority handling between data flows of several users on FACH
Identification of UEs on common transport channels
Multiplexing/demultiplexing of upper layer PDUs into/from transport blocks
delivered to/from the physical layer on common transport channels
Traffic volume measurement
Transport Channel type switching
Ciphering for transparent mode RLC
Access Service Class selection
II. RLC
The functions of RLC include:
Segmentation and reassembly, concatenation, padding and transfer of user data.
Flow control
Error correction, in-sequence delivery of upper layer PDUs and duplicate
detection
Sequence numbers check
Protocol error detection and recovery
Ciphering
Suspend/resume function
III. PDCP
The functions of PDCP include:
Header compression and decompression of IP data streams at the transmitting
and receiving entity respectively.
Transfer of user data
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22. Protocols and Signalling Analysis Chapter 1
HUAWEI UMTS Radio Access Network UTRAN Interface Protocols and Functions
Forward the PDCP-SDU from non-access stratum to RLC, and multiplex different
RBs to the same RLC entity.
IV. BMC
The functions of BMC include:
Storage of Cell Broadcast Messages
Traffic volume monitoring and radio resource request for CBS
Scheduling of BMC messages
Transmission of BMC messages to UE
Delivery of Cell Broadcast messages to upper layer (NAS)
1.2.4 L1 Functions
The functions of L1 (physical layer) mainly includes:
Measurements and indication to higher layers (e.g. FER, SIR, interference power,
transmission power, etc)
Macro-diversity distribution/combining and soft handover execution;
Frequency and time (chip, bit, slot, frame) synchronization;
Closed-loop power control;
RF processing;
Multiplexing of transport channels and demultiplexing of coded composite
transport channels;
Mapping of coded composite transport channels on physical channels;
Modulation and spreading/demodulation and despreading of physical channels;
The detailed functions and relevant specifications of L1 are involved with the basic
principles of W-CMDA which is out of the range of this manual. Refer to relevant
protocols for the details.
1.3 Iub interface
1.3.1 Iub Protocol Structure
Iub interface is the logical interface between RNC and NodeB. The protocol stack of Iub
interface is illustrated in Figure 1-4.
1-6
23. Protocols and Signalling Analysis Chapter 1
HUAWEI UMTS Radio Access Network UTRAN Interface Protocols and Functions
Radio Network User Plane
Radio Control Plane
FACH FP
RACH FP
DCH FP
PCH FP
Network Node B
Layer Application Part
(NBAP)
Transport Network
Control Plane
ALCAP
Transport
Layer Q.2630.1
Q.2150.2
SSCF-UNI SSCF-UNI
SSCOP SSCOP
AAL Type 5 AAL Type 5 AAL Type 2
ATM
Physical Layer
Figure 1-4 Protocol Stack of Iub interface
Iub interface specifications are shown in Figure 1-5.
Radio Network User Plane
Control Plane Dedicated Common
Radio NBAP Channels Channels
Network TS 25.433 TS 25.427 TS 25.435
Layer
Transport
Network
Control Plane
Transport Signaling
Transport TS 25.426
Layer (Dedicated Channel
Dedicated Common
Transport) Channel Channel
NBAP Transport Transport Transport
TS 25.434
(Common Channel
TS 25.432 Transport) TS 25.426 TS 25.434
TS 25.431
Physical Layer
Figure 1-5 Iub interface specifications
In this section, only the functions and procedures of radio network layer are given. For
the transport layer, refer to “Chapter 2 Transfer Network Layer Procedure Analysis”.
The radio network user plane of Iub interface is to transfer the data between RNC and
NodeB. The plane is implemented by means of Frame Protocol (FP) of transport
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24. Protocols and Signalling Analysis Chapter 1
HUAWEI UMTS Radio Access Network UTRAN Interface Protocols and Functions
channels. According to the type of transported data, the FP can be classified as FP for
common transport channel and FP for Dedicated transport channel.
1.3.2 Functions of NBAP
NBAP is the Radio network control plane of Iub interface, which provides the following
functions:
Cell Configuration Management. This function gives the CRNC the possibility to
manage the cell configuration information in a NodeB.
Common Transport Channel Management. This function gives the CRNC the
possibility to manage the configuration of Common Transport Channels in a
NodeB.
System Information Management. This function gives the CRNC the ability to
manage the scheduling of System Information to be broadcast in a cell.
Resource Event Management. This function gives the NodeB the ability to inform
the CRNC about the status of NodeB resources.
Configuration Alignment. This function gives the CRNC and the NodeB the
possibility to verify and enforce that both nodes have the same information on the
configuration of the radio resources.
Measurements on Common Resources. This function allows the NodeB to initiate
measurements in the NodeB. The function also allows the NodeB to report the
result of the measurements.
Radio Link Management. This function allows the CRNC to manage radio links
using dedicated resources in a NodeB.
Radio Link Supervision. This function allows the CRNC to report failures and
restorations of a Radio Link.
Compressed Mode Control. This function allows the CRNC to control the usage of
compressed mode in a NodeB.
Measurements on Dedicated Resources. This function allows the CRNC to initiate
measurements in the NodeB. The function also allows the NodeB to report the
result of the measurements.
DL Power Drifting Correction. This function allows the CRNC to adjust the DL
power level of one or more Radio Links in order to avoid DL power drifting between
the Radio Links.
Reporting of General Error Situations. This function allows reporting of general
error situations, for which function specific error messages have not been defined.
1.3.3 NBAP Procedures
NBAP procedures are divided into common procedures and dedicated procedures.
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25. Protocols and Signalling Analysis Chapter 1
HUAWEI UMTS Radio Access Network UTRAN Interface Protocols and Functions
NBAP common procedures are procedures that request initiation of a UE context
for a specific UE in NodeB or are not related to a specific UE. NBAP common
procedures also incorporate logical O&M procedures.
NBAP dedicated procedures are procedures that are related to a specific UE
context in NodeB. This UE context is identified by a UE context identity.
The two types of procedures may be carried on separate signaling links.
I. NBAP Common Procedures
The mapping between the NBAP functions and NBAP elementary procedures is shown
in the Table 1-2.
Table 1-2 Mapping between functions and NBAP elementary procedures
Function Elementary Procedure(s)
Cell Configuration Management a) Cell Setup
b) Cell Reconfiguration
c) Cell Deletion
Common Transport Channel Management a) Common Transport Channel Setup
b) Common Transport Channel Reconfiguration
c) Common Transport Channel Deletion
System Information Management System Information Update
Resource Event Management a) Block Resource
b) Unblock Resource
c) Resource Status Indication
Configuration Alignment a) Audit Required
b) Audit
c) Reset
Measurements on Common Resources a) Common Measurement Initiation
b) Common Measurement Reporting
c) Common Measurement Termination
d) Common Measurement Failure
Radio Link Management. Radio Link Setup
II. NBAP Dedicated Procedures
The mapping between the NBAP functions and NBAP dedicated procedures is shown
in Table 1-3.
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26. Protocols and Signalling Analysis Chapter 1
HUAWEI UMTS Radio Access Network UTRAN Interface Protocols and Functions
Table 1-3 Mapping between functions and NBAP dedicated procedures
Function Dedicated Procedure(s)
Radio Link Management. a) Radio Link Addition
b) Radio Link Deletion
c) Unsynchronized Radio Link Reconfiguration
d) Synchronized Radio Link Reconfiguration
Preparation
e) Synchronized Radio Link Reconfiguration
Commit
f) Synchronized Radio Link Reconfiguration
Cancellation
g) Radio Link Pre-emption
Radio Link Supervision. a) Radio Link Failure
b) Radio Link Restoration
Compressed Mode Control a) Radio Link Setup
b) Radio Link Addition
c) Compressed Mode Command
d) Unsynchronized Radio Link Reconfiguration
e) Synchronized Radio Link Reconfiguration
Preparation
f) Synchronized Radio Link Reconfiguration Commit
g) Synchronized Radio Link Reconfiguration
Cancellation
Measurements on Dedicated Resources a) Dedicated Measurement Initiation
b) Dedicated Measurement Reporting
c) Dedicated Measurement Termination
d) Dedicated Measurement Failure
DL Power Drifting Correction Downlink Power Control
Reporting of General Error Situations Error Indication
1.3.4 Iub FP for Common Transport Channel Data Transfer
Iub FP for common transport channel data transfer is the radio network user plane of
Iub interface which provides the following services:
Transport of Transport Block Set (TBS) between the NodeB and the CRNC for
common transport channels (including RACH, FACH PCH)
Support of transport channel synchronization mechanism
Support of Node Synchronization mechanism
I. RACH Data Transfer
RACH Data Transfer procedure is used to transfer data received from Uu interface from
NodeB to CRNC.
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The procedure is realized by a transmission of Data Frame from NodeB to CRNC, as
shown in Figure 1-6.
NodeB CRNC
RACH Data Frame
Figure 1-6 RACH data transfer procedure
II. FACH Data Transfer
FACH Data Transfer procedure is used to transfer data from CRNC to NodeB.
The procedure is realized by a transmission of Data Frame from CRNC to NodeB, as
shown in Figure 1-7.
NodeB CRNC
FACH Data Frame
Figure 1-7 FACH data transfer procedure
III. PCH Data Transfer
PCH Data Transfer procedure is used to transfer data from CRNC to NodeB.
The procedure is realized by a transmission of Data Frame from CRNC to NodeB, as
shown in Figure 1-8.
NodeB CRNC
PCH Data Frame
Figure 1-8 PCH data transfer procedure
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IV. Node Synchronization
Node synchronization is to obtain the round trip delay (RTD) of the transmission
between information entities over the Iub interface.
In the Node Synchronization procedure, the RNC sends a DL Node Synchronization
control frame to NodeB containing the parameter T1. Upon reception of a DL Node
Synchronization control frame, the NodeB shall respond with UL Node Synchronization
Control Frame, indicating t2 and t3, as well as t1 which was indicated in the initiating DL
Node Synchronization control frame, as shown in Figure 1-9.
NodeB CRNC
DL Node Synchronization
UL Node Synchronization
Figure 1-9 Node synchronisation procedure
TheT1, T2, T3 parameters are defined as:
T1: RNC specific frame number (RFN) that indicates the time when RNC sends
the frame through the SAP to the transport layer.
T2: NodeB specific frame number (BFN) that indicates the time when NodeB
receives the correspondent DL Node synchronization frame through the SAP from
the transport layer.
T3: NodeB specific frame number (BFN) that indicates the time when NodeB
sends the frame through the SAP to the transport layer.
V. DL Transport Channels Synchronization
DL transport channel synchronization procedure is used to synchronize the transport
channel after the transport channel has been set up or used to maintain the
synchronization of the transport channel when there is no DL data frame.
In the DL transport channel synchronization procedure, CRNC sends a DL
Synchronization control Frame to NodeB. This message indicates the target CFN.
Upon reception of control message, NodeB shall immediately respond with UL
Synchronization Control Frame indicating the Time of Arrival (ToA) for the DL
Synchronization frame and the CFN indicated in the received message, as shown in
Figure 1-10.
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NodeB CRNC
DL Synchronization
UL Synchronization
Figure 1-10 FACH and PCH transport channels synchronization procedure
VI. DL Timing Adjustment
Timing Adjustment procedure is used for NodeB to indicate the CRNC the incorrect
arrival time of downlink data to the NodeB.
Timing adjustment procedure is initiated by the NodeB if a DL frame arrives outside of
the defined arrival window. If the DL frame has arrived before the ToAWS or after the
ToAWE, NodeB will include the ToA and the target CFN in the Timing Adjustment
Control Frame, as shown in Figure 1-11.
NodeB CRNC
Timing Adjustment
.
Figure 1-11 FACH and PCH Timing Adjustment procedure
The arrival window and the time of arrival are defined as follows:
Time of Arrival Window Endpoint (ToAWE): ToAWE represents the time point
by which the DL data shall arrive to the NodeB from Iub. The ToAWE is defined as
the amount of milliseconds before the last time point from which a timely DL
transmission for the identified CFN would still be possible taking into account the
NodeB internal delays. ToAWE is set via control plane. If data does not arrive
before ToAWE a Timing Adjustment Control Frame shall be sent by NodeB.
Time of Arrival Window Startpoint (ToAWS): ToAWS represents the time after
which the DL data shall arrive to the NodeB from Iub. The ToAWS is defined as the
amount of milliseconds from the ToAWE. ToAWS is set via control plane. If data
arrives before ToAWS a Timing Adjustment Control Frame shall be sent by
NodeB.
Time of Arrival (ToA): ToA is the time difference between the end point of the DL
arrival window (ToAWE) and the actual arrival time of DL frame for a specific CFN.
A positive ToA means that the frame is received before the ToAWE, a negative
ToA means that the frame is received after the ToAWE.
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1.3.5 Iub FP for Dedicated Transport Channel Data Transfer
Iub FP for dedicated transport channel data transfer is the radio network user plane of
Iub interface which provides the following services:
Transport of TBS between SRNC and NodeB
Transport of outer loop power control information between the SRNC and the
NodeB
Support of transport channel synchronization mechanism
Support of Node Synchronization mechanism
Transfer of radio interface parameters from the SRNC to the NodeB
I. Uplink Data Transfer
NodeB SRNC
UL Data Frame
Figure 1-12 Uplink data transfer procedure
Uplink Data Transfer procedure is used to transfer data from NodeB to SRNC.
The procedure is realized by a transmission of UL Data Frame from NodeB to SRNC,
as shown in Figure 1-12.
Two modes can be used for the UL transmission: normal mode and silent mode. The
mode is selected by the SRNC when the transport bearer is set up and signalled to the
NodeB with the relevant control plane procedure.
In normal mode, the NodeB shall always send an UL Data Frame to the RNC for
all the DCHs in a set of coordinated DCHs regardless of the number of Transport
Blocks of the DCHs.
In silent mode and in case only one transport channel is transported on a transport
bearer, the NodeB shall not send an UL Data Frame to the RNC when it has
received a TFI indicating “number of TB equal to 0” for the transport channel
during a TTI.
In silent mode and in case of coordinated DCHs, when the NodeB receives a TFI
indicating “number of TB equal to 0” for all the DCHs in a set of coordinated DCHs,
the NodeB shall not send an UL data frame to the RNC for this set of coordinated
DCHs.
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II. Downlink Data Transfer
NodeB SRNC
DL Data Frame
Figure 1-13 Downlink data transfer procedure
Downlink Data Transfer procedure is used to transfer data from SRNC to NodeB.
The procedure is realized by a transmission of DL Data Frame from SRNC to NodeB,
as shown in Figure 1-13.
The NodeB shall consider a transport bearer synchronized only after it has received at
least one data frame on this transport bearer before the latest time of arrival (LTOA).
The NodeB shall consider the DL user plane for a certain RL synchronized if all
transport bearers established for carrying DL DCH data frames for this RL are
synchronized.
Only when the DL user plane is considered synchronized, the NodeB shall transmit the
data on the DL DPDCH.
When the DL user plane is considered synchronized and the NodeB does not receive a
valid DL Data Frame in a TTI, it assumes that there is no data to be transmitted in that
TTI for this transport channel, and shall act as one of the following cases:
If the NodeB is aware of a TFI value corresponding to zero bits for this transport
channel, this TFI is assumed. When combining the TFI’s of the different transport
channels, a valid TFCI might result and in this case data shall be transmitted on
Uu.
If the NodeB is not aware of a TFI value corresponding to zero bits for this
transport channel or if combining the TFI corresponding to zero bits with other
TFI’s, results in an unknown TFI combination, the handling will be different. In the
former case, at each radio frame, the NodeB shall build the TFCI value of each
CCTrCH, according to the TFI of the DCH data frames multiplexed on this
CCTrCH. In the latter case, NodeB shall transmit only the DPCCH without TFCI
bits.
III. Outer Loop Power Control Information Transfer
Outer loop power control information transfer procedure is used to transfer power
control information from SRNC to NodeB.
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The procedure is realized by a transmission of Outer Loop PC control frame from
SRNC to NodeB, as shown in Figure 1-14. The Outer Loop PC control frame can be
sent via any of the transport bearers dedicated to one UE.
Based, for example, on the CRC Indicator (CRCI) values and on the quality estimate in
the UL frames, SRNC modifies the SIR target used by the UL Inner Loop Power Control
by including the absolute value of the new SIR target in the Outer Loop PC control
frame sent to the NodeB's. At the reception of the Outer Loop PC control frame, the
NodeB shall immediately update the SIR target used for the inner loop power control
with the specified value.
NodeB SRNC
Outer Loop PC
Figure 1-14 Outer loop power control information transfer procedure
IV. Radio Interface Parameter Update
Radio interface parameter update procedure is used to update radio interface
parameters which are applicable to all RL’s for the concerning UE. Both synchronized
and unsynchronized parameter updates are supported.
The procedure is realized by a transmission of Radio Interface Parameter Update
control frame SRNC to the NodeB, as shown in Figure 1-15
NodeB SRNC
Radio Interface Parameter Update
Figure 1-15 Radio interface parameter update procedure
V. Node Synchronization
Node synchronization procedure is to obtain the round trip delay (RTD) of the
transmission between information entities over the Iub interface.
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In the Node Synchronization procedure, the SRNC sends a DL Node Synchronization
control frame to NodeB containing the parameter T1. Upon reception of a DL Node
Synchronization control frame, the NodeB shall respond with UL Node Synchronization
control frame, indicating t2 and t3, as well as t1 which was indicated in the initiating DL
Node Synchronization control frame, as shown in Figure 1-16.
NodeB SRNC
DL Node Synchronization
UL Node Synchronization
Figure 1-16 Node synchronization procedure
The T1, T2, T3 parameters are defined as:
T1: RNC specific frame number (RFN) that indicates the time when RNC sends
the frame through the SAP to the transport layer.
T2: NodeB specific frame number (BFN) that indicates the time when NodeB
receives the correspondent DL synchronization frame through the SAP from the
transport layer.
T3: NodeB specific frame number (BFN) that indicates the time when NodeB
sends the frame through the SAP to the transport layer.
VI. Downlink Transport Channel Sychronization
Downlink transport channel synchronization procedure is used to achieve or restore the
synchronization of the DCH data stream in DL direction, and as a keep-alive procedure
in order to maintain activity on the Iur/Iub transport bearer.
In the downlink transport channel synchronization procedure, CRNC sends a DL
Synchronization control frame to NodeB. This message indicates the target CFN. Upon
reception of control message, NodeB shall immediately respond with UL
Synchronization control frame indicating the Time of Arrival (ToA) for the DL
Synchronization frame and the CFN indicated in the received message, as shown in
Figure 1-17.
UL Synchronization control frame shall always be sent, even if the DL Synchronization
control frame is received by the NodeB within the arrival window.
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NodeB SRNC
DL Synchronization
UL Synchronization
Figure 1-17 DCH synchronization procedure
VII. Downlink Timing Adjustment
The timing adjustment procedure is used to keep the synchronization of the DCH data
stream in DL direction.
Timing adjustment procedure is initiated by the NodeB if a DL frame arrives outside of
the defined arrival window. If the DL frame has arrived before the ToAWS or after the
ToAWE, NodeB will include the ToA and the target CFN in the Timing Adjustment
control frame, as shown in Figure 1-18.
NodeB SRNC
Timing Adjustment
Figure 1-18 Timing adjustment procedure
1.4 Iur Interface
1.4.1 Iur Protocol Structure
Iur interface is the interface between RNCs, The protocol stack of Iur interface is
illustrated in Figure 1-19.
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