Stochastic model of TCP and UDP traffic in IEEE 802.11b/g

IEEE 802.11 networks have been widely explored since last decade and IEEE802.11g was proposed to increase the data rate of wireless networks up to 54Mbps which ensure backward capability with IEEE802.11b. The main goal of increasing the data rate is to handle high data rate traffic. Many studies have been conducted to analyze the performance of wireless networks using Quality of service constrains. However there are limited studies which try to understand the behavior of TCP traffic while UDP is present. The IEEE 802.11 family has a standard mechanism to handle TCP and UDP traffic without consideration of traffic priorities. In the presence of UDP traffic, the TCP cause high delay and saturation. In this paper we embedded the Bianchi´s Markov chain model with our packet fragmentation technique to reduce the saturation impact on TCP traffic while UDP is present. We have analyzed the throughput for IEEE802.11b/g considering response times and packet retransmission. The theoretical results are validated by simulation and it is observed that the TCP packet rate is improved by using our proposed approach.