IMPROVED BINARY INCREASE CONGESTION CONTROL ALGORITHMS FOR DATA TRANSFER IN SATELLITE NETWORK

In our previous work[18], it was proved that the performance of bic-tcp was good under satellite network, and a new adaptive window increment based bic-tcp algorithm (bic_AWI) was proposed to show an improved data transfer in satellite network. We, implemented the idea on ns2’s implementation of bic tcp. Proposed modifications has been made on bic-tcp, and improvement in performance has been realized. Even though, the congestion avoidance mechanism of standard bic will be very much influenced by this proposed adaptive window change strategy, in update method of the bic, some of the parameters like BICTCP_B are kept as constant during finding a optimum tcp windows size. The constant value BICTCP_B has been cahnged dynamically with respect to the acceleration and deceleration of rtt, has shown a considerable improvement in performance. Based on that idea, we proposed a dynamic parameter estimation based binary increase congestion control algorithm (bic_DPE) [19] for data transfer in satellite network. In this method, with respect to the acceleration of deceleration of rtt the important parameter BICTCP_B will be dynamically adjusted to provide best performance. Further, we added the mechanism to minimize packet loss during terminal handover. Proposed modifications has been made on bic-tcp, and the performance of the improved protocol “bic_AWI” and “bic_DPE” has been compared with normal bic-tcp under Iridium satellite constellation. The performance of the algorithms has been measured using suitable metrics and the proposed bic_DPE performed better than normal bic-tcp as well as our previous “bic_AWI” method.