A Performance Comparison of Equation-Based and GAIMD Congestion Control in Mobile Ad Hoc Networks

Fast-growing applications like streaming media make TCP a poor fit. Because the UDP protocol lacks congestion control, equation-based and AIMD-based congestion control schemes have been two promising alternative to TCP for real-time multimedia streaming over the Internet. Past studies have shown that they are able to maintain throughput smoothness and achieve reasonable fairness with competing TCP flows in wireline networks. However, their behavior remains not clear in mobile ad hoc network (MANET). In this paper, we compare the general AIMD-based congestion control mechanism (GAIMD) with equation-based congestion control mechanism (TFRC TCP-friendly rate control) over a wide range of MANET scenario, in terms of throughput fairness and smoothness. Our results show that TFRC and GAIMD (0.2, 0.125) are able to maintain throughput smoothness in MANET, but at the same time, they obtain less throughput than the competing TCP flows. Our results also show that TFRC changes its sending rate more smoothly than GAIMD (0.2, 0.125) does, but it gets the least throughput compares with TCP and GAIMD (0.2, 0.125).