Patent ID: 7826603

Claim:
A method of alerting a group in a communications network, the method comprising: receiving, by a PTT server, an INVITE request message to initiate an alert to the group; determining, by the PTT server, that a SIP Require header in the INVITE request message indicates that alerting is needed for members of the group not already in a group session; joining, by the PTT server, an alert originator to the group session if the originator was not already a member of the group session; and initiating a call in response to the alert, the call including: sending, by the PTT server, another INVITE request message to invite the members not already in the group session to join the group session; receiving, by the PTT server, an INVITE OK response message wherein the response includes a request for a speech token; sending, by the PTT server, an ACK message in response to the request for the speech token, wherein an Event header provides mechanism for requesting and granting the speech token in the INVITE OK response & the ACK messages respectively.