ETSI TS 124 091

ETSI TS 124 091 gives the stage 3 description of the call transfer supplementary services.

The present document specifies the procedures used at the radio interface (Reference point Um as defined in 3GPP TS 24.002) for normal operation, registration, erasure, activation, deactivation, invocation and interrogation of call transfer 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.

In 3GPP TS 24.010 the general aspects of the specification of supplementary services at the layer 3 radio interface are given.

3GPP TS 24.080 specifies the formats and coding for the supplementary services.

Definitions and descriptions of supplementary services are given in 3GPP TS 22.004, 3GPP TS 22.08x and 3GPP TS 22.09x-series. 3GPP TS 22.091 is related specifically to call transfer supplementary services.

The technical realization of supplementary services is described in 3GPP TS 23.011, 3GPP TS 23.08x and 3GPP TS 23.09x-series. 3GPP TS 23.091 is related specifically to call transfer supplementary services.

The procedures for Call Control, Mobility Management and Radio Resource management at the layer 3 radio interface are defined in 3GPP TS 24.007 and 3GPP TS 24.008.

The following supplementary services belong to the call transfer supplementary services and are described in the present document:

• Explicit Call Transfer (ECT) (see clause 4).