Improving TCP performance using the adaptive link layer retransmission algorithm over wireless channel

We investigate the TCP performance over Radio Link Protocol (RLP). The link layer persistence is important parameter to ensure reliable delivery of traffic across the link. When the link layer persistence is chosen, the interaction between TCP and RLP must be considered. Irrespective of the degree of wireless channel loss, existing algorithms use the fixed retransmission value. Therefore, we suggest the adaptive link layer retransmission algorithm. The proposed algorithm changes the link layer recovery persistence, considering interaction between TCP and RLP. We show the improvement of the normalized TCP throughput using the suggested algorithm. The results presented are based on computer simulation using the OPNET.