TCP Protocol Optimization On Mobile Devices Design And Implementation

With the development of Internet and wireless data communication technologies, wireless Internet access becomes a new hot spot. Mobile devices, such as a smart phone and PDA, etc, are widely used. Because the TCP protocol is not designed according to the character of wireless network and mobile device, its performance is undesirable on throughput and energy consumption.The problem can be resolved in parts by optimizing the congestion control algorithm of TCP, including the sending rate slowing down during the avoiding congestion course and using the timestamp option to judge whether it begins a loss recovery phase incorrectly. The TCP's behavior can be benefit from the optimization and the device's energy consumption also can be reduced.At first, this paper introduced the basic principle of TCP protocol and the most popular TCP protocol software – TCP Reno. And the method and character are researched when mobile device is used to access Internet by wireless network. Then a optimizing design of congestion avoiding mechanism and loss detecting mechanism are proposed. At last the paper also presents a result of contrastive test between Reno and the optimized TCP in a simulate environment which is established by a PC and a GPRS module. It shows that the optimized TCP can achieve between 20 and 30% effective throughput.