Content for TS 25.401 Word version: 18.0.0

3.1 Definitions 3.2 Abbreviations 3.3 Notation
...

1 Scope p. 7

The present document describes the overall architecture of the UTRAN, including internal interfaces and assumptions on the radio and Iu interfaces.

2 References p. 7

The following documents contain provisions which, through reference in this text, constitute provisions of the present document.

References are either specific (identified by date of publication, edition number, version number, etc.) or non specific.
For a specific reference, subsequent revisions do not apply.
For a non-specific reference, the latest version applies. In the case of a reference to a 3GPP document (including a GSM document), a non-specific reference implicitly refers to the latest version of that document in the same Release as the present document.

[1] Void

[2]

TS 23.110: "UMTS Access Stratum Services and Functions".

[3] Void

[4]

TS 25.442: "UTRAN Implementation Specific O&M Transport".

[5]

TS 25.402: "Synchronisation in UTRAN, Stage 2".

[6]

TS 23.003: "Numbering, Addressing and Identification".

[7]

TS 25.331: " Radio Resource Control (RRC); Protocol specification".

[8]

TS 23.101: "General UMTS Architecture".

[9]

TS 25.414: " UTRAN Iu Interface Data Transport & Transport Signalling".

[10]

TS 25.424: "UTRAN Iur Interface Data Transport & Transport Signalling for Common Transport Channel Data Streams".

[11]

TS 25.434: "UTRAN Iub Interface Data Transport & Transport Signalling for Common Transport Channel Data Streams".

[12]

RFC 2460 (1998-12): "Internet Protocol, Version 6 (Ipv6) Specification".

[13] Void

[14]

RFC 768 (1980-08): "User Datagram Protocol".

[15]

"Information technology - Open Systems Interconnection - Network service definition", X.213, ISO/IEC 8348.

[16]

"Information technology - Open Systems Interconnection - Network service definition Amendment 1: Addition of the Internet protocol address format identifier", X.213/Amd.1, ISO/IEC 8348.

[17]

RFC 791 (1981-09): "Internet Protocol".

[18]

TS 25.426: "UTRAN Iur and Iub Interface Data Transport & Transport Signalling for DCH Data Streams".

[19] Void

[20]

TS 23.236: "Intra-domain connection of Radio Access Network (RAN) nodes to multiple Core Network (CN) nodes".

[21]

TR 43.930: "Iur-g interface; Stage 2".
→ to date, withdrawn by 3GPP

[22]

TR 44.901: "External Network Assisted Cell Change".

[23]

TS 48.018: "General Packet Radio Service (GPRS); BSS GPRS Protocol (BSSGP)".

[24]

TS 25.460: "UTRAN Iuant Interface: General Aspects and Principles".

[25]

TS 25.461: "UTRAN Iuant Interface: Layer 1".

[26]

TS 25.462: "UTRAN Iuant Interface: Signalling Transport".

[27] Void

[28]

TS 23.251: "Network sharing - Architecture and functional description".

[29]

TS 25.410: "UTRAN Iu Interface: general aspects and principles".

[30]

TS 25.346: "Introduction of the Multimedia Broadcast Multicast Service (MBMS) in the Radio Access Network (RAN); Stage 2".

[31]

TS 25.413: "UTRAN Iu Interface RANAP Signalling".

[32]

TS 25.466: "UTRAN Iuant Interface: Application part".

[33]

TS 25.305: "Stage 2 functional specification of UE positioning in UTRAN".

[34]

RFC 4548 (2006-05): "Internet Code Point (ICP) Assignments for NSAP Addresses"

[35]

TS 36.300: "Evolved Universal Terrestrial Radio Access (E-UTRA), Evolved Universal Terrestrial Radio Access Network (E-UTRAN); Overall description; stage 2".

[36]

TS 23.060: "General Packet Radio Service (GPRS); Service description; Stage 2".

[37]

RFC 3168 (2001-09): "The Addition of Explicit Congestion Notification (ECN) to IP".

[38]

TS 37.320: "Universal Terrestrial Radio Access (UTRA) and Evolved Universal Terrestrial Radio Access (E-UTRA); Radio measurement collection for Minimization of Drive Tests (MDT); Overall description; Stage 2".

3 Definitions and abbreviations p. 8

3.1 Definitions p. 8

For the purposes of the present document, the following terms and definitions apply:

[1.28Mcps TDD - Multi-frequency Cell:

If multiple frequencies are configured in one cell, the cell is defined as the multi-frequency cell.]

[1.28Mcps TDD - Primary frequency:

In a multi-frequency cell, the frequency on which the P-CCPCH is transmitted is defined as primary frequency.]

[1.28Mcps TDD - Secondary frequency:

In a multi-frequency cell, any frequency other than the primary frequency is defined as secondary frequency.]

ALCAP:

generic name for the transport signalling protocols used to set-up and tear-down transport bearers

Cell:

Radio Network object that can be uniquely identified by a User Equipment from a (cell) identification that is broadcasted over a geographical area from one UTRAN Access Point

A Cell is either FDD or TDD mode.

DCN-ID:

DCN identity identifies a specific decicated core network (DCN).

Iu:

interface between an RNC and an MSC, SGSN or CBC, providing an interconnection point between the RNS and the Core Network. It is also considered as a reference point

Iub:

interface between the RNC and the Node B

Iur:

logical interface between two RNCs

Whilst logically representing a point to point link between RNCs, the physical realisation need not be a point to point link.

Iur-g:

logical interface between RNC/BSS and BSS

Whilst logically representing a point to point link between RNC/BSS and BSS, the physical realisation need not be a point to point link.

Logical Model:

Logical Model defines an abstract view of a network or network element by means of information objects representing network element, aggregations of network elements, the topological relationship between the elements, endpoints of connections (termination points), and transport entities (such as connections) that transport information between two or more termination points

The information objects defined in the Logical Model are used, among others, by connection management functions. In this way, a physical implementation independent management is achieved.

Network sharing supporting UE:

as defined in TS 23.251.

Network sharing non-supporting UE:

as defined in TS 23.251.

Node B:

logical node in the RNS responsible for radio transmission / reception in one or more cells to/from the UE

The logical node terminates the Iub interface towards the RNC.

Radio Resources:

resources that constitute the radio interface in UTRAN, e.g. frequencies, scrambling codes, spreading factors, power for common and dedicated channels

Node B Application Part:

Radio Network Signalling over the Iub

Radio Network Controller:

logical node in the RNS in charge of controlling the use and the integrity of the radio resources

Controlling RNC:

role an RNC can take with respect to a specific set of Node B's

There is only one Controlling RNC for any Node B. The Controlling RNC has the overall control of the logical resources of its node B's.

MBMS Master RNC:

role an RNC can take with respect to one or more specific MBSFN cluster(s)

MRNC may be used for Inter-RNC MBSFN operation whenever dynamic synchronization of radio resources used for MBMS services is centrally controlled. There is only one MBMS Master RNC for any MBSFN cluster, which may control one or more MBSFN cluster(s). The MRNC has the overall control of the logical resources of the RNSs that are used for MBSFN operation within the MBSFN cluster(s).

Radio Network Subsystem:

RNS can be either a full UTRAN or only a part of a UTRAN

An RNS offers the allocation and release of specific radio resources to establish means of connection in between an UE and the UTRAN. A Radio Network Subsystem contains one RNC and is responsible for the resources and transmission/reception in a set of cells.

Serving RNS:

role an RNS can take with respect to a specific connection between an UE and UTRAN

There is one Serving RNS for each UE that has a connection to UTRAN. The Serving RNS is in charge of the radio connection between a UE and the UTRAN. The Serving RNS terminates the Iu for this UE.

Drift RNS:

role an RNS can take with respect to a specific connection between an UE and UTRAN

An RNS that supports the Serving RNS with radio resources when the connection between the UTRAN and the UE need to use cell(s) controlled by this RNS is referred to as Drift RNS.

Radio Access Network Application Part:

Radio Network Signalling over the Iu

Radio Network Subsystem Application Part:

Radio Network Signalling over the Iur

RRC Connection:

point-to-point bi-directional connection between RRC peer entities on the UE and the UTRAN sides, respectively

An UE has either zero or one RRC connection.

Stand-Alone SMLC:

as defined in TS 25.305.

User Equipment:

Mobile Equipment with one or several UMTS Subscriber Identity Module(s)

A device allowing a user access to network services via the Uu interface. The UE is defined in ref. TS 23.101. If this term is used in the context of Iur-g, it means MS in case it uses radio resources of a DBSS.

Universal Terrestrial Radio Access Network:

UTRAN is a conceptual term identifying that part of the network which consists of RNCs and Node Bs between Iu an Uu

The concept of UTRAN instantiation is currently undefined.

User Datagram Protocol:

as defined in IETF RFC 768 [14].

UTRAN Access Point:

conceptual point within the UTRAN performing radio transmission and reception

A UTRAN access point is associated with one specific cell, i.e. there exists one UTRAN access point for each cell. It is the UTRAN-side end point of a radio link.

Radio Link:

"radio link" is a logical association between a single User Equipment and a single UTRAN access point

Its physical realisation comprises one or more radio bearer transmissions.

Radio Link Set:

set of one or more Radio Links that has a common generation of Transmit Power Control (TPC) commands in the DL

Uu:

Radio interface between UTRAN and the User Equipment

RAB sub-flows:

Radio Access Bearer can be realised by UTRAN through several sub-flows

These sub-flows correspond to the NAS service data streams that have QoS characteristics that differ in a predefined manner within a RAB e.g. different reliability classes.

RAB sub-flows have the following characteristics:

The sub-flows of a RAB are established and released at the RAB establishment and release, respectively.
The sub-flows of a RAB are submitted and delivered together at the RAB SAP.
The sub-flows of a RAB are carried over the same Iu transport bearer.
The sub-flows of a RAB are organised in a predefined manner at the SAP and over the Iu interface. The organisation is imposed by the NAS as part of its co-ordination responsibility.

Set of co-ordinated DCHs:

set of co-ordinated DCHs is a set of dedicated transport channels that are always established and released in combination

Individual DCHs within a set of co-ordinated DCHs cannot be operated on individually e.g. if the establishment of one DCH fails, the establishment of all other DCHs in the set of co-ordinated DCHs shall be terminated unsuccessfully. A set of coordinated DCHs is transferred over one transport bearer. All DCHs in a set of co-ordinated DCHs shall have the same TTI.

Shared Network Area (SNA):

Area consisting of one or more LA's to which access can be controlled.

3.2 Abbreviations p. 10

For the purposes of the present document, the following abbreviations apply:

AAL

ATM Adaptation Layer

AAL2

ATM Adaptation Layer 2

ALCAP

Access Link Control Application Part

APN

Access Point Name

ATM

Asynchronous Transfer Mode

BM-IWF

Broadcast Multicast Interworking Function

BMC

Broadcast/Multicast Control

BSS

Base Station Subsystem

CBC

Cell Broadcast Centre

CBS

Cell Broadcast Service

Core Network

CRNC

Controlling Radio Network Controller

DCH

Dedicated Channel

DCN

Dedicated Core Network

Downlink

DRNS

Drift RNS

DSP

Domain Specific Part

EAB

Extended Access Barring

E-DCH

Enhanced UL DCH

EDGE

Enhanced Data rates for Global Evolution

FACH

Forward Access Channel

FFS

For Further Study

GERAN

GSM EDGE Radio Access Network

GSM

Global System for Mobile Communications

GTP

GPRS Tunnelling Protocol

GWCN

GateWay Core Network

HPLMN

Home PLMN

IDP

Initial Domain Part

IPv4

Internet Protocol, version 4

IPv6

Internet Protocol, version 6

Location Area

L-GW

Local GateWay

MAC

Medium Access Control

MBMS

Multimedia Broadcast Multicast Service

MCCH

MBMS point-to-multipoint Control Channel

MDT

Minimization of Drive-Tests

MOCN

Multi Operator Core Network

MRNC

MBMS Master Radio Network Controller

MSCH

MBMS point-to-multipoint Scheduling Channel

MTCH

MBMS point-to-multipoint Traffic Channel

NACC

Network Assisted Cell Change

NAS

Non Access Stratum

NBAP

Node B Application Part

NNSF

NAS Node Selection Fuction

NSAP

Network Service Access Point

PCH

Paging Channel

PLMN

Public Land Mobile Network

PTM

Point To Multipoint

PTP

Point To Point

QoE

Quality of Experience

QoS

Quality of Service

RAB

Radio Access Bearer

RACH

Random Access Channel

RANAP

Radio Access Network Application Part

RET

Remote Electrical Tilting

RIM

RAN Information Management

RNC

Radio Network Controller

RNL

Radio Network Layer

RNS

Radio Network Subsystem

RNSAP

Radio Network Subsystem Application Part

RNTI

Radio Network Temporary Identity

SAB

Service Area Broadcast

SAS

Stand-Alone SMLC

SIPTO

Selected IP Traffic Offload

SIPTO@LN

Selected IP Traffic Offload at the Local Network

SMLC

Serving Mobile Location Centre

SNA

Shared Network Area

SRNC

Serving Radio Network Controller

SRNS

Serving RNS

S-GW

Serving GateWay

TMA

Tower Mounted Amplifier

TBSS

Target BSS

TEID

Tunnel Endpoint Identifier

TMGI

Temporary Mobile Group Identity

TNL

Transport Network Layer

TTI

Transmission Time Interval

UDP

User Datagram Protocol

User Equipment

Uplink

UMTS

Universal Mobile Telecommunication System

URA

UTRAN Registration Area

USIM

UMTS Subscriber Identity Module

UTRAN

Universal Terrestrial Radio Access Network

3.3 Notation p. 12

For the purposes of the present document, the following notations apply:

[FDD]

This tagging of a word indicates that the word preceding the tag "[FDD]" applies only to FDD. This tagging of a heading indicates that the heading preceding the tag "[FDD]" and the section following the heading applies only to FDD.

[TDD]

This tagging of a word indicates that the word preceding the tag "[TDD]" applies only to TDD, including 3.84Mcps TDD, 7.68Mcps TDD and 1.28Mcps TDD. This tagging of a heading indicates that the heading preceding the tag "[TDD]" and the section following the heading applies only to TDD, including 3.84Mcps TDD, 7.68Mcps TDD and 1.28Mcps TDD.

[3.84Mcps TDD]

This tagging of a word indicates that the word preceding the tag "[3.84Mcps TDD]" applies only to 3.84Mcps TDD. This tagging of a heading indicates that the heading preceding the tag "[3.84Mcps TDD]" and the section following the heading applies only to 3.84Mcps TDD.

[1.28Mcps TDD]

This tagging of a word indicates that the word preceding the tag "[1.28Mcps TDD]" applies only to 1.28Mcps TDD. This tagging of a heading indicates that the heading preceding the tag "[1.28Mcps TDD]" and the section following the heading applies only to 1.28Mcps TDD.

[7.68Mcps TDD]

This tagging of a word indicates that the word preceding the tag "[7.68Mcps TDD]" applies only to 7.68Mcps TDD. This tagging of a heading indicates that the heading preceding the tag "[7.68Mcps TDD]" and the section following the heading applies only to 7.68Mcps TDD.

[FDD - …]

This tagging indicates that the enclosed text following the "[FDD - " applies only to FDD. Multiple sequential paragraphs applying only to FDD are enclosed separately to enable insertion of TDD specific (or common) paragraphs between the FDD specific paragraphs.

[TDD - …]

This tagging indicates that the enclosed text following the "[TDD - " applies only to TDD including 3.84Mcps TDD, 7.68Mcps TDD and 1.28Mcps TDD. Multiple sequential paragraphs applying only to TDD are enclosed separately to enable insertion of FDD specific (or common) paragraphs between the TDD specific paragraphs.

[3.84Mcps TDD - …]

This tagging indicates that the enclosed text following the "[3.84Mcps TDD - " applies only to 3.84Mcps TDD. Multiple sequential paragraphs applying only to 3.84Mcps TDD are enclosed separately to enable insertion of FDD and TDD specific (or common) paragraphs between the 3.84Mcps TDD specific paragraphs.

[1.28Mcps TDD - …]

This tagging indicates that the enclosed text following the "[1.28Mcps TDD - " applies only to 1.28Mcps TDD. Multiple sequential paragraphs applying only to 1.28Mcps TDD are enclosed separately to enable insertion of FDD and TDD specific (or common) paragraphs between the 1.28Mcps TDD specific paragraphs.

[7.68Mcps TDD - …]

This tagging indicates that the enclosed text following the "[7.68Mcps TDD - " applies only to 7.68Mcps TDD. Multiple sequential paragraphs applying only to 7.68Mcps TDD are enclosed separately to enable insertion of FDD and TDD specific (or common) paragraphs between the 7.68Mcps TDD specific paragraphs.

Message

When referring to a message in the specification, the MESSAGE NAME is written with all letters in upper case characters followed by the word "message", e.g. RADIO LINK SETUP REQUEST message.

When referring to an information element (IE) in the specification, the Information Element Name is written with the first letters in each word in upper case characters and all letters in Italic font followed by the abbreviation "IE", e.g. Transport Format Set IE.

Value of an IE

When referring to the value of an information element (IE) in the specification, the "Value" is enclosed by quotation marks, e.g. "Abstract Syntax Error (Reject)".

Frame

When referring to a control or data frame in the specification, the CONTROL/DATA FRAME NAME is written with all letters in upper case characters followed by the words "control/data frame", e.g. FACH FLOW CONTROL control frame.

4 General principles p. 13

The general principles guiding the definition of UTRAN Architecture as well as the UTRAN interfaces are the following:

Logical separation of signalling and data transport networks.
UTRAN and CN functions are fully separated from transports functions. Addressing scheme used in UTRAN and CN shall not be tied to the addressing schemes of transport functions. The fact that some UTRAN or CN function resides in the same equipment as some transport functions does not make the transport functions part of the UTRAN or the CN.
[FDD - Macro diversity is fully handled in the UTRAN.]
Mobility for RRC connection is fully controlled by the UTRAN.
When defining the UTRAN interfaces the following principles were followed: The functional division across the interfaces shall have as few options as possible.
Interfaces should be based on a logical model of the entity controlled through this interface.
One Physical Network Element can implement multiple Logical Nodes.

Transport Network Control Plane is a functional plane in the interfaces protocol structure that is used for the transport bearer management. The actual signalling protocol that is in use within the Transport Network Control Plane depends on the underlying transport layer technology. The intention is not to specify a new UTRAN specific Application Part for the Transport Network Control Plane but to use signalling protocols standardised in other groups (if needed) for the applied transport layer technology.