This TS specifies the procedures used at the radio interface (reference point Um as defined in TS 04.02
) for normal operation, registration, erasure, activation, deactivation, interrogation and network invocation of call offering supplementary services. Provision and withdrawal of supplementary services is an administrative matter between the mobile subscriber and the service provider and cause no signalling on the radio interface.
The following supplementary services belong to the call offering supplementary services and are described in this TS:
Call forwarding unconditional (CFU)
Call forwarding on mobile subscriber busy (CFB)
Call forwarding on no reply (CFNRy)
Call forwarding on mobile subscriber not reachable (CFNRc)