Hybrid Multi-Radio Transmission Diversity Scheme to Improve Wireless TCP Performance in an Integrated LTE and HSDPA Networks

The performance of Transmission Control Protocol (TCP) degrades over wireless links which are characterized by varying channel condition and high error rate. TCP misinterprets these as network congestion. In this paper, we analyze the TCP send rate of parallel multi-radio transmission diversity (MRTD) schemes with and without redundancy in heterogeneous wireless networks (HWNs). Through developing a cross-layer model, MAC layer packet error rate and link rate are taken into consideration. By comparing the performance of these schemes, we propose a hybrid MRTD scheme which aims at obtaining good tradeoff between robustness and efficiency to improve TCP performance. The feasibility of the proposed scheme is validated by user-level simulation. Moreover, system-level simulation results show that hybrid MRTD scheme improves the wireless TCP performance comparing with parallel MRTD schemes.