GSM 09.02 - Version 5.3.0 - Digital cellular telecommunications - ETSI

Page 468
GSM 09.02 Version 5.3.0: August 1996
19 Supplementary services procedures
The following application contexts exist for handling of supplementary services:
- accessUnstructuredSsContext;
- accessFunctionalSsContext.
The accessUnstructuredSsContext refers to a simple MAP users, for which the corresponding MAP
process can be identified by the MAP-Provider directly.
However, the accessFunctionalSsContext refers to a complex MAP-User consisting of several processes.
For this user, a process co-ordinator is defined for each network entity, in order to identify the correct
process to invoke. These processes open and validate the dialogue, then invoke the necessary
operation-specific process. These processes are described below.
19.0 Functional supplementary service processes
19.0.1 Functional supplementary service process co-ordinator for MSC
Upon receipt of a CM-Service request with CM-service type = SS, the MSC initiates the process access
request procedure towards the VLR as described in clause 21 of this ETS.
Once a CM connection is established, the MSC can handle supplementary service indications from the MS.
Table 19.0/1 shows the co-ordinating process' reaction on receipt of specific SS service indications on the
air interface. After the relevant process is invoked, the received air interface service indication is sent to
that process. The creation of service requests on the basis of air interface messages is described in
TS GSM 09.11.
Service indication received Process invoked
A_REGISTER_SS_ind REGISTER_SS_MSC
A_ERASE_SS_ind ERASE_SS_MSC
A_ACTIVATE_SS_ind ACTIVATE_SS_MSC
A_DEACTIVATE_SS_ind DEACTIVATE_SS_MSC
A_INTERROGATE_SS_ind INTERROGATE_SS_MSC
A_REGISTER_PASSWORD REGISTER_PASSWORD_MSC
Table 19.0/1: Relationship between received service indication and invoked process in the MSC
Figure 19.0/1 shows the co-ordinating process in the MSC.