3 Abbreviations and definitions

23.0093GPPHandover proceduresRelease 17TS

3.1 Abbreviations

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

3G_MSC A third generation MSC that supports the Iu interface and optionally the A interface

3G_MSC‑A The controlling 3G_MSC on which the call was originally established

3G_MSC‑B The 3G_MSC to which the UE is handed over in a Basic Handover

3G_MSC‑B’ The 3G_MSC to which the UE is handed over in a Subsequent Handover

BSC Base Station Controller

BSS Base Station System

BSS-A The BSS from which the MS is being handed over

BSS-B The BSS to which the MS is being handed over

BTS Base Transceiver Station

CSG Closed Subscriber Group

CSS CSG Subscriber Server

E-UTRAN Evolved Universal Terrestrial Radio Access Network

GERAN GSM EDGE Radio Access Network

ISC International Switching Centre

LCLS Local Call Local Switch

MS Mobile Station

MSC A second generation Mobile Services Switching Centre that only supports the A interface

MSC‑A The controlling MSC on which the call was originally established

MSC‑B The MSC to which the MS is handed over in a Basic Handover

MSC‑B’ The MSC to which the MS is handed over in a Subsequent Handover

MME Mobility Management Entity

RNC Radio Network Controller

RNS Radio Network Subsystem

SBSS Serving BSS

SNA Shared Network Area

SRNS Serving RNS

STN-SR Session Transfer Number for SR-VCC

UE A User Equipment is a terminal that supports USIM and the UMTS Uu interface

UE/MS A terminal that supports USIM, SIM, the Uu interface and the Um interface

UESBI UE Specific Behaviour Information

USIM UMTS Subscriber Identity Module

Other abbreviations used in the GSM specifications are listed in 3GPP TR 21.905 [2a].

3.2 Definitions

The following terms are used in this Technical Specification:

A/Gb mode: mode of operation of the MS when connected to the Core Network via GERAN and the A and/or Gb interfaces. Throughout this specification the term GSM refers to GERAN A/Gb mode.

AoIP-Selected codec (Target): the codec selected by the target BSS, to be used by the UE/MS in GERAN A/Gb mode after the handover to the BSS using A interface over IP.

AoIP-Supported Codecs List (Anchor): a list of codecs for GERAN A/Gb mode derived by the anchor MSC‑A/3G_MSC-A based on the codecs supported by the MS and the codecs available at the anchor MSC‑A/3G_MSC-A for A interface over IP, and provided by MSC-A/3G_MSC-A to MSC-B/3G_MSC-B during Inter-MSC handover/relocation with MAP signalling. Within the list, the codecs are ordered in decreasing order of priority, the first entry in the list being the highest priority codec (preferred codec) and the last entry the lowest priority codec.

AoIP-Available Codecs list (MAP): a list of codecs for GERAN A/Gb mode available for the target AoIP interface signalled via MAP.

CSG ID list: for a specific PLMN-ID the list of CSG IDs for which the MS has a valid subscription. The CSG ID list for the registered PLMN can be derived from the CSG subscription data provided by the HLR or the CSS to the anchor MSC. The CSG ID lists for the equivalent PLMNs can be derived from the CSG subscription data provided by the HLR.

Iu mode: mode of operation of the MS when connected to the Core Network via GERAN or UTRAN and the Iu interface. Throughout this specification the term UMTS refers to UTRAN or GERAN Iu mode.

Iur interface: the logical interface between two UTRAN RNSs.

Iur-g interface: the logical interface between two BSSs or a BSC and an RNC and it is only considered in Iu mode.

Iu Currently used codec: the codec used by the UE/MS in UTRAN or GERAN Iu mode before a handover or SRNS relocation.

Iu Selected codec: the codec to be used by the UE/MS in UTRAN or GERAN Iu mode after the handover or SRNS relocation.

Iu Supported Codecs List: a list of codecs supported by the MS and by the core network, provided by MSC-A/3G_MSC-A to 3G_MSC-B during Inter-MSC handover/relocation. The Iu Supported Codecs List may contain separate list of codecs for UTRAN Iu mode and GERAN Iu mode. Within each list, the codecs are ordered in decreasing order of priority, the first entry in the list being the highest priority codec (preferred codec) and the last entry the lowest priority codec.

Default speech codec: In UTRAN Iu mode the default speech codec is the UMTS AMR or UMTS AMR2 codec, dependent on the capabilities of the UE/MS. For a description of how the network determines the default UMTS speech codec, see 3GPP TS 24.008 [10], clause 5.2.1.11. If necessary, 3G_MSC-B shall use the Radio Resource Information instead of the GSM Bearer Capability, since the GSM Bearer Capability is not available in MSC-B.

In GERAN Iu mode the default speech codec is the AMR FR codec.

SRVCC MSC: MSC server enhanced for SRVCC as defined in 3GPP TS 23.216 [26] clause 5.3.2.

vSRVCC MSC: MSC server enhanced for vSRVCC as defined in 3GPP TS 23.216 [26] clause 5.3.2a.

UE Specific Behaviour Information – Iu (UESBI-Iu): information that is sent from the MSC to the RAN and that can be used to derive specific information about the UE’s capabilities.

For the purposes of the present document, the following terms and definitions given in 3GPP TS 23.216 [26] apply:

SRVCC

vSRVCC

For the purposes of the present document, the following terms and definitions given in 3GPP TS 23.237 [31] apply:

SCC AS

For the purposes of the present document, the following terms and definitions given in 3GPP TS 24.008 [10] apply:

CSG cell

CSG ID