TCP-aware cross-layer design in cognitive radio networks

In this paper, we propose an optimal TCP throughput framework to optimize the TCP throughput in CR networks, which jointly considers the channel sensing decision and access policy as well as low layer design parameters. The TCP throughput optimization is achieved by a two step process. First, we select a channel to maximize the spectrum utilization by reducing the probability of collision with primary users. Secondly, for an available and accessed channel, a cross-layer approach is proposed to improve TCP throughput which adaptively adjusts the modulation and coding scheme/frame size based on the observed channel gain. Simulation results show that the TCP throughput can be improved substantially compared with the existing approach that maximizes physical layer throughput.