Some mechanisms to improve TCP/IP performance over wireless and mobile computing environment

The Internet and wireless networks are two of the most important technical developments that have had a direct effect on the lives of people over the past few years. The next step is to combine these two technologies to provide wide-area wireless Internet access. Currently, TCP/IP (Transport Control Protocol/Internet Protocol) is the most important protocol that integrates a wide range of different physical networks into the global Internet. The environment of wireless networks violates many assumptions made by traditional TCP/IP. Compared with fixed and wired networks, wireless networks have a high bit-error rate (BER) and offer less available bandwidth. Furthermore, the host mobility also results in packet losses or delays during handoff procedures. Hence, the performance of TCP/IP over such wireless networks without any modification suffers significant degradation of throughput and high interactive delay. In this paper, we propose some schemes to improve the performance of TCP/IP over wireless networks according to their characteristics. We analyze the performance of TCP/IP under different network conditions by using ns-2 (Network Simulator version 2) to facilitate comparisons with previous studies. The simulation results show that our proposed mechanisms achieve better performance than other protocols.