Performance evaluation for TCP with traffic shaping over satellite communications

Nowadays the demand for high-mobility remote access broadband services like satellite networks is becoming more popular. Therefore arise of the network congestion seems to be the major problems for most of network operators. TCP (transmission control protocol) is being studied in order to provide reliable data delivery over broadband satellite communications. TCP per se provides various congestion avoidance algorithms that may be used over the satellite link. However, TCP may somehow have to face with some difficulties due to the satellite transmission and propagation delay. In such network where significant losses are occurred, it is difficult for TCP to respond to the required throughput but in other words it may degrade the performance. In this paper, traffic shaping is investigated in order to ease the problem of congestion. To shape the traffic prior to the entrance of satellite communication system, the paper makes use of NoQ, network of queue, and then the consequent TCP congestion avoidance algorithm is employed. Several types of queue are assumed as well as TCP window size is changeable. The results from this study reveals that NoQ is directly giving an impact to window size as of TCP protocol over satellite communications. By performing intensive simulations, under different input rates, the impressive results are obtained. NoQ indicates that in some certain cases the improvement of throughput is reaching high as 15%. The improvement may be varied, based upon the network traffic condition over the satellite communications (that is the sliding window size) and input traffic rates