Patent ID: 6545995
Filing Date: 2003-04-08
Classification: H04W

Abstract:
A method of maintaining a group call in a mobile communication system comprising a network infrastructure, and mobile stations that communicate with the network infrastructure over a radio path, whose frame structure comprises time slots, the method comprising:establishing a group call in which a first mobile station is prioritized, the mobile stations that participate in the group call communicating in speech items, and the frame structure comprising time slots that a second mobile station sending a speech item employs in its speech item; allocating only to the first mobile station time slots or time periods from the frame structure of said group call in which time slots or time periods only the first mobile station may send signalling messages to said network infrastructure; and sending the first mobile station and a third mobile station data indicating in which time slots or time periods only the first mobile station may send signalling messages to said network infrastructure, the third mobile station refraining from sending signalling messages in said time slots or time periods allocated to the first mobile station.