The adaptive permission reservation protocol for wireless communications

The adaptive permission reservation (APR) protocol is proposed as a wireless multiple access control (MAC) protocol for multiplexing voice traffic. The APR belongs to the category of protocols that introduces random access to the time division multiple access (TDMA). In contrast to the normal approach of using a fixed sending permission at every voice terminal, APR uses simple heuristics to estimate the number of contending terminals. The estimation is based on the difference between the number of collisions and the number of successfully contentions over a period of time. Simulation results show that, with slow speech activity detectors, the performance of APR approximates that of the ideal packet reservation multiple access (PRMA) when the channel bit rate is low. In other words, the heuristics is an excellent estimation to the number of contending terminals under that type of environment. In addition, APR also exhibits significant improvement over the original PRMA protocol when fast speech activity detectors are used.