7 Service Capability Detection

22.2793GPPCombined Circuit Switched (CS) and IP Multimedia Subsystem (IMS) sessionsStage 1TS

Tools: ARFCN - Frequency Conversion for 5G NR/LTE/UMTS/GSM

7.1 General

The Service Capability Detection may indicate to the user that the UEs have interoperable CSICS capability and that the access network(s) have the necessary network functionality to carry the combinational service.

The detection of the capabilities of the recipient terminal and the operators’ networks shall ensure that information is updated in case of change of terminal.

An operator should have the mechanism to inhibit the capability check, or at least indicate to UE that it should not be performed.

Note: An operator may want to inhibit the capability check for CSICS in order to optimise the usage of radio resources.

It shall be possible for the (CSICS capable) UEs to have the information, prior to initiating a combinational service, regarding the type of capabilities, which are jointly supported by both UEs, without user intervention.

Due to the handover of the participating users to an access network which does not support combinational services, service capability detection may be needed during a CS call to notify the user of the service availability.

7.2 User privacy

Participants in a CS call or IMS session may choose not to reveal their identity, even though this may prevent the establishment of a combinational session.

During the service capability detection and exchange of information process, the user’s privacy settings shall be respected. The applicable privacy settings are as described in clauses 8 and 9. Additionally, the user shall be able to restrict the information exchanged by the service capability detection application and the user’s consent should be requested prior to the exchange of information.

NOTE: The terminal is not normally aware of existing Calling Line Identity Restriction / Connected Line Restriction settings in the network, hence the need for the user to be able to configure the service capability detection application not to reveal such information.