Auto Rate Protocol with Congestion Control for Multi-Hop Ad Hoc Networks

Nodes in wireless multi-hop Ad Hoc networks need to contend for the shared wireless channel,which could result in congestions and waste the wireless bandwidth resource.To utilize the multirate capability of Ad Hoc physical layer more efficiently,an ACC-AR(Adaptive Congestion Control-Auto Rate) protocol is proposed with dynamic transmission window mechanism.The receiver sets the highest feasible transmission rate allowed by the channel condition,and controls the sender's transmission window according to its congestion level.The sender then transmits the back-to-back DATA frames according to the value of transmission window.The simulation results show that ACC-AR can effectively utilize the channel condition,increase the network saturation throughput by about 80% under heavy network load,and achieve congestion control in the MAC(Media Access Control) layer.