METHOD AND APPARATUS TO REDUCE DISPATCH DELAYS IN DISPATCH COMMUNICATION NETWORKS

摘要

A communication network supports push-to-talk communications with reduced dispatching delays by eliminating channel grant/request handshaking on the uplink and the downlink. A pool of communication channels (12) can be associated with a group of nets (NET1; NET2; NETm) that include one or more mobile terminals. Any terminal can send dispatch traffic immediately on an assigned uplink channel simply by seizing the channel. The network detects such traffic and retransmits it on a downlink channel monitored by the group of nets. Along with the retransmitted traffic, the network sends a net ID and a new downlink channel assignment. Terminals in the targeted net process the retransmitted traffic and non-targeted terminals switch to the new channel. Alternatively, the control channel can be multiplexed to signal traffic channel assignments as needed for all nets, and traffic can be transmitted on the indicated channels for reception by targeted terminals. The reduced delays particularly benefit networks incorporating satellite relays.