Hop by Hop congestion control system for adhoc networks

As the development of Internet continues, congestion control has become a major issue to the computer network society. Most of the congestion control schemes fall into two categories : end to end and hop-by-hop (HBH) congestion control schemes. The hop-by-hop algorithm can achieve short delays and quick responses to the congestion situations, and cause no packet loss. It can also minimize the bandwidth requirement and achieve high buffer usage level for nodes along the transmission path. In HBH mechanisms, traffic control is used at each node along the traffic flow path. As a consequence, congestion along the traffic flow path could be detected immediately and appropriate control could be carried out (e.g., buffering packets) at the immediate upstream node to avoid the congestion condition. In this paper the HBH congestion control scheme is implemented using network simulator and the simulation results are analyzed as to how effectively it sends feedback to its upstream nodes and also decreases the rate of sending accordingly.