Throughput analysis of split-channel MAC with p-persistent CSMA on the control channel and reservation scheme

We deal with the split-channel MAC where total bandwidth splits into one control channel for RTS/CTS dialogue and several data sub-channels for data packet transmission. We consider the with-reservation scheme which allows successful RTS/CTS dialogue to be stored in a virtual queue for future transmission when all of the data sub-channels are occupied. We obtain the throughput of the split-channel MAC, when the control channel adopts p-persistent CSMA and has with-reservation scheme, by modeling the stochastic behavior of the sum of the number of occupied data sub-channels and the number of successful RTS/CTS dialogues in the virtual queue, and the state of control channel as a two-dimensional discrete time Markov Chain (DTMC). The numerical results show that throughput of with-reservation scheme outperforms that of without-reservation scheme in particular when the data packet size is large. Also, from the numerical results, we obtain the optimal value of p to maximize throughput as the number of stations and average packet size vary.