Performance of TCP over radio link with adaptive channel coding and ARQ

The performance of transmission control protocol (TCP) over wireless links could degrade due to handoff, high bit error rate and long roundtrip delay on the air interface. Radio link protocol (RLP) uses channel coding and ARQ to mitigate impairment over wireless channels. In this paper, we study the performance of TCP over adaptive RLP. We investigate this problem in the context of the TDMA (IS-136 and IS-130) wireless network, where the wireless data is transmitted through the reliable RLP. The RLP is modified with an adaptive channel coding scheme. First, we analyze the throughput of RLP with combination of ARQ and fixed channel codes. Second, we consider an adaptive channel coding scheme using punctured convolutional codes and ARQ that maximizes the throughput under variable channel conditions. Third, we simulate the effect of radio environment and compare the performance of TCP over RLP with fixed and adaptive channel coding. Our simulation results indicate significant improvement in throughput performance for TCP over adaptive RLP