Performance improvements of TCP protocol for mobile data service

In this paper, the data service protocol which can support data services more efficiently between the mobile host in the wireless network and the fixed host in wired network is investigated. The wireless link has a high bit error rate compared with the wire link. Thus, the TCP performance for the data service is degraded in wire and wireless interworking environments. We propose a method which could reduce performance degradation. In order to support the data service efficiently, an interworking module which connects the wireless and wire links is added as a simple protocol processing function to improve performance. The proposed interworking module analyzes the header information of the TCP frame. If the received TCP frame is a duplicated frame, the TCP frame is discarded. If the interworking module receives a retransmission request, the interworking module performs the retransmission procedure. According to simulation results, the proposed IWF shows a better performance than the traditional IWF in view of delay and throughput in the wire and wireless interworking environments.