| 摘要 |
A circuit-switched call is established between said subscriber devices, and then a first subscriber device transmits a request for transferring said circuit-switched call to be carried via a group call established over a packet-switched connection. In a network element linking information is created for handing the said call over to a packet-switched connection, and in response to said subscriber devices and all relevant network elements having an appropriate information for establishing a packet-switched connection, a speech channel of said circuit-switched call is terminated. Next, a packet-switched connection is established between said subscriber devices, and then a group call is established over said packet-switched connection, whereby said subscriber devices are included in said group call on the basis of said linking information.
|
