Multiple access protocols for indoor wireless communications

The authors present an investigation of multiple access techniques which would be suitable for indoor radio systems offering both voice and data capability. A suitable cellular-based TDMA radio system is chosen that would overcome the difficulties of the indoor radio channel, such as shadow fading and multipath spread of signals, through the application of diversity techniques and resource sharing. Two new hybrid multiple access protocols are described. Polling is also considered as a potential access technique, but is found to be inefficient in terms of the frame time needed for reservations. In order to predict the performance of the new protocols in the indoor environment, a radio network is both simulated on a computer and analyzed mathematically. It is shown how a contention-based scheme can support a data throughput of 2.6 Mbits/sec with 50 active voice calls in one cell