Z.1 General

23.2283GPPIP Multimedia Subsystem (IMS)Release 18Stage 2TS

This clause describes the required functions to support IMS-based restricted local operator services (RLOS). RLOS services are operator owned services that are offered to the following categories of subscribers:

– Roaming users who are subscribers of other operators with whom the local operator has no roaming agreement, or the local operator cannot communicate with their network.

– Roaming users who are subscribers of other operators with whom the local operator has roaming agreements for IMS services and for Restricted Operator Local Services.

– Operator own subscribers who roamed in cells with restricted services. These subscribers may or may not have been successfully authenticated prior to roaming in cells with restricted services.

NOTE: Operator restricted services can also be offered to the local operator own subscribers roaming in unrestricted areas, however this is out of scope.

RLOS is used only for originating services.

In this version of the specification, RLOS is only defined for users connected to IMS over EPS (see TS 23.401 [70]);