Published Paper Details:

Abstract : Faster data communication is today requirement in any wireless system. TCP is most widely used transport protocol. TCP provides reliable delivery of data in wired network. In wireless network, congestion event and non-congestion event are present. Traditional TCP always considers as packet is lost due to congestion. It fails to perform well in wireless network. Many TCP variants have been proposed for congestion control but they cannot distinguish reason of dropping packets that is either due to congestion or due to bit error. For Congestion reduction router queue play important role, like drop tail and RED. Here, study and comparative analysis of TCP variants has been done with different parameters like throughput, end to end delay, number of dropped packets and packet delivery fraction. By analyzing these comparisons conclude that NewReno give batter result With RED queue as compare to other but there is no solution for bit error and high priority packet drop over RED. It reduces congestion window every time when their congestion error but when there is a bit error then no need to reduce the transmission rate. MOD_TCPNR is capable to reduce the unnecessary reduction of congestion window and retransmissions caused by bit error or random error. MOD_TCPNR uses the ECN indication of TCP header for distinguishes issue of congestion from bit error and Congestion notification of high priority traffic. Simulation results shows that MOD_TCPNR gives better results compare to NewReno. Simulation has been performed in ns2.35.