For the purposes of the present document, the terms defined in TR 21.905
for the purpose of this specification, and unless otherwise stated, a CN node is either an MSC or an SGSN.
NAS node selection Function:
The function used to assign specific network resources (i.e. MSC or SGSN) to serve a mobile station and subsequently route the traffic to the assigned network resource.
Network Resource Identifier:
A specific parameter used to identify the CN node assigned to serve a mobile station.
Each CN node in a pool have to be assigned one unique non-broadcast LAI/RAI that it use in case it want to be offloaded. Each CN node in the pool has to be aware of the non-broadcast LAI/RAI assigned to the other CN nodes in the pool, because in case of re-distribution the 'target CN node' will retrieve data (e.g. IMSI, security context, MM & PDP contexts) from the 'offloaded CN node' based on non-broadcast LAI/RAI.
A 'null-NRI' indicates to a radio node (BSC/RNC) that the NAS Node Selection Function shall be used for selecting a CN node to receive a message. There is one unique 'null-NRI' in a PLMN supporting pool functionality. In MOCN shared networks (see TS 23.251
) with multiple CN Operators, there is one unique 'null-NRI' per CN operator. That is, in MOCN networks the RAN Operator handles multiple 'null-NRIs'.
A pool area is an area within which a MS may roam without need to change the serving CN node. A pool area is served by one or more CN nodes in parallel. All the cells controlled by a RNC or BSC belong to the same one (or more) pool area(s).
for the purpose of this specification, and unless otherwise stated, a RAN node is either an RNC or a BSC.
RAN node service area:
This area contains all the cells controlled by the RNC or BSC.
For the purposes of the present document, the abbreviations given in TR 21.905
and the following apply. An abbreviation defined in the present document takes precedence over the definition of the same abbreviation, if any, in TR 21.905
Base Station Controller
BSSGP Virtual Connection Identifier
Circuit Switched Media Gateway
Dedicated Core Network
Directory Name Server
Intra Domain NAS Node Selector
Location Area Identity
Multi-Operator Core Network
Mobile Switching Centre
Non Access Stratum
Network Resource Identifier
Operation and Maintenance
Routing Area Identity
Radio Access Network
Radio Network Controller
Serving Radio Network Subsystem
Temporary Mobile Station Identity
Temporary Logical Link Identifier