Patent ID: 9264467
Filing Date: 2016-02-16
CPC Classification: G06F,H04L,H04W

Claim Text:
1. A method for opening an ad-hoc Push-To-Talk (PTT) over Cellular (PoC) session in a PoC system, including a first PoC server and a second PoC server, comprising the steps of: receiving, by the first PoC server, a session INVITE message from a PoC client requesting session initiation, the session INVITE message including information of at least one group identifier; checking, by the first PoC server, the at least one group identifier included in the session INVITE message received by the first PoC server; sending a group list information request message including the at least one group identifier and a value indicating a conference server, from the first PoC server, to the second PoC server hosting a group list corresponding to the group identifier; and receiving group list information, at the first PoC server, from the second PoC server, in response to the group list information request message.