TCP enhancement technology in cognitive network based on cross-layer designing

The difference between cognitive wireless network and traditional wireless network lies in the function of spectrum sensing and channel switching. In cognitive networks, cognitive users must sense the spectrum. When the primary users access, it must switch to another channel in order to avoid the interference to the primary users. Therefore, it is necessary to improve the traditional TCP to make it adapt to the spectrum sensing and channel switching in cognitive network. The cross-layer designing between TCP and MAC can eliminate retransmission problems caused by the spectrum sensing, and the proposed “TCP-improved algorithm” can solve the problems of low utilization rate of bandwidth or network congestion when cognitive users switch its channel. The experimental results show that the “TCP-improved algorithm” has the best performance in cognitive network.