Sanjesh S. Pawale, Research Scholar
Department of Computer Engineering, Bharati Vidyapeeth (Deemed to be University), College of Engineering, Pune, India.
Sandeep B. Vanjale, Professor, Shashank D. Joshi, Professor, Suhas H. Patil, Professor
Department of Computer Engineering, Bharati Vidyapeeth (Deemed to be University), College of Engineering, Pune, India.
Performance Improvement of TCP Westwood by Dynamically Adjusting Congestion Window in Wireless Network
Authors
Abstract
Reliable delivery of data across the network is assured by Transmission Control Protocol (TCP) which performs well in wired networks with low bit-error rates. But in wireless networks, links have higher bit-error rates; violating many of the assumptions made by TCP, causing performance degradation. This paper proposes a modification in congestion control mechanism of TCP Westwood. The proposed algorithm, Westwood-M, dynamically adjusts the congestion window (cwnd) in Slow Start (SS), Additive Increase (AI) and Multiplicative Decrease (MD) phases. The proposed algorithm calculates the appropriate threshold using Round Trip Time (RTT) estimation and set cwnd according to be estimated threshold. A good threshold and cwnd improves the transmission performance of TCP. Results carried out in NS2 simulator shows considerable improvement in TCP performance than standard TCP variants.