Congestion Avoidance Routing for MANETs

In a Mobile Ad Hoc Network (MANET), communication connections need to adapt to frequent and unpredictable topology changes due to the mobility, energy constraints, and limited computing power of the mobile hosts. Early solutions address this fundamental requirement by employing techniques that can reconnect a broken link quickly with a low overhead; however, this strategy cannot cope with the increased frequency of broken links in a high mobility environment. To resolve the problem, greedy techniques (i.e., packet switching or geographic routing) have emerged. The scheme rely on any mobile hosts along the general direction towards the destination node to help forward data packets. However, the greedy approach suffers from packet loss because the packet forwarding policy does not consider traffic congestion along the route or the direction.

In this project, we propose a congestion avoidance routing (CAR) technique for two greedy protocols, Connectionless Approach (CLA) and Contention-based Forwarding (CBF), to address the packet loss problem by rerouting packets dynamically to avoid traffic congestion. To demonstrate the improvement of the proposed techniques, we studied and showed the simulation results on not only different metrics (i.e., packet delivery, end-to-end delay, control overhead, and energy consumption) but also different network environments/settings (i.e., real-world road network, congestion metric, and size of contention area). The extensive performance results show that the proposed techniques outperform existing approaches.