RTT fair congestion control algorithm for satellite interactive networks

This paper presents the adaptive logarithmic increase and adaptive decrease algorithm, called A-LIAD, as an alternative for the current TCP congestion control algorithm. We defined new increasing function in the fashion of logarithm depending on the increasing factor α which is different from the other logarithmic increase algorithm adopting the fixed vale of α = 2 leading to binary increase. The α value is derived in the function of RTT through the analysis. With the modification of increasing function applied for the congestion avoidance phase, hybrid scheme is also presented for the slow start phase. From this hybrid scheme, we can avoid overshooting problem in the slow start phase even without SACK option. To verify the feasibility of the algorithm for the deployment in the high speed and long distance network, several aspects are evaluated through the NS-2 simulation. We performed simulations for intra-fairness and inter-fairness as well as the friendliness in the different conditions of varying RTTs, bandwidth and PER. From these simulations, we showed that although A-LIAD is not the best in the all aspects, it provides competitive performance in almost all aspects especially in the start-up and packet loss impact and thus can be an alternative TCP congestion control algorithm for the high BDP networks including satellite network.