22.0913GPPExplicit Call Transfer (ECT) supplementary serviceStage 1TS
The ECT supplementary service enables the served mobile subscriber (subscriber A) who has two calls , each of which can be an incoming or outgoing call, to connect the other parties in the two calls and release the served mobile subscribers own connection.
Prior to transfer, the connection shall have been established on the call between subscriber A and subscriber B. On the call between subscriber A and subscriber C, either the connection shall have been established prior to transfer, or, as a network option, transfer can occur while subscriber C is being informed of the call (i.e. the connection has not yet been established.)
4.1 Applicability to telecommunication services
This service is applicable to telephony (TS:11) only.