3 Definitions and abbreviations

22.0913GPPExplicit Call Transfer (ECT) supplementary serviceStage 1TS

3.1 Definitions

For the purposes of the present document, the following definitions apply.

Alerting state: the remote subscriber is being informed of the call (i.e. the connection has not yet been established for that call).

Answered state: the connection has been established on the call to the remote subscriber.

Subscriber A: is the served mobile subscriber, the one who has subscribed to, and invokes the Explicit Call Transfer supplementary service.

Subscriber B: is the other party in one of subscribers A’s calls. By convention, in the present document it is considered that the connection has been established on this call.

Subscriber C: is the other party in another of subscribers A’s calls.

Subscriber D: is the forwarded-to subscriber of call forwarded by subscriber C.

NOTE: Each of subscriber B, C and D can be a mobile or a fixed subscriber, and each of them is referred to as "remote party".

Successful invocation: The ECT supplementary service is successfully invoked if the outcome of all checks (e.g. subscription, states of calls, resources) performed by the network on the received ECT request from the served subscriber are successful.

3.2 Abbreviations

All abbreviations used within the present document are given in 3GPP TS 21.905 [1].