On the capacity of packet reservation multiple access with capture in personal communication systems

A new Markovian model is developed to analyze the packet reservation multiple access (PRMA) protocol over Rician fading channels with lognormal shadowing. The packet dropping probability and the voice user capacity are defined as the performance measures. A new formula is derived to evaluate the dropping probability in the fading environment. The analytical results from our new formula show close agreement with those from computer simulations. The capture effect on the PRMA system performance is also studied. We found that, with capture, the user capacity will be improved and the service quality will degrade gracefully when the number of active users in the system increases. Using the dropping probability as the criterion, we also determine the optimal permission probability in a microcellular environment.