A packet channel sharing protocol for microcellular mobile communications

Because new microcellular systems have high-speed transmission, they are expected to provide the infrastructure for voice and data communication. To implement packet radio communication on such systems, packet channel sharing protocol for DCA systems (PCSD) scheme is proposed for sharing dynamically assigned TDMA channels with circuit-switched calls. In this protocol, packet channels are temporally established only when packets are generated. This is done by transmitting downlink signals, consecutively, from a cell station (CS); and subsequent uplink packets are transmitted in accordance with the access control signal associated with each downlink signal. If no packet is transmitted within a predetermined period, the CS stops downlink transmission to release the packet channel. The characteristics of this protocol are evaluated using computer simulations of four-channel TDMA/TDD. The results indicate that the protocol improves channel capacity by more than 10 percent (when packet throughput is 0.2) compared to individual assignment in which channels are separately assigned to packet and circuit-switched calls, respectively, without deteriorating packet throughput.