Maintenance of group call in mobile communication system

摘要

method of maintaining a group call in a mobile communication system comprising a network infrastructure and mobile stations, includes establishing a group call in which a first mobile station is prioritized. The mobile stations participating in the group call communicate in speech items, the frame structure comprising time slots that a second mobile station sending a speech item employs in its speech item. The first mobile station is allocated time slots or time periods in which only the first mobile station can transmit signaling messages to the network infrastructure. Data is sent to the first mobile station and the third mobile stations indicating in which time slots or time periods only the first mobile station can send signaling messages to the network infrastructure. The third mobile stations refrain from sending their signaling messages in the time slots or time periods (204) allocated to the first mobile station.