Congestion Free Routing in Adhoc Networks

Problem statement: A Mobile Ad-Hoc Network (MANET) is a temporary network; the mobile devices in an ad-hoc network are communicating through wireless links without any pre-existing infrastructure. The one major problem of this network is network congestion, it may take place at any intermediate nodes when data packets are traveling from source to destination. The major problems of congestion or high data loss, increasing End to End and retransmission packets which affects the overall network performance. The main goal of congestion control is to effectively utilize the existing network resources and maintain the network load below the capacity. Approach: This study presents the Congestion Free Routing in Adhoc networks (CFR), based on dynamically estimated mechanism to monitor network congestion by calculating the average queue length at the node level. While using the average queue length, the nodes’ congestion status divided into the three zones (safe zone, likely to be congested zone and congested zone). CFR utilizes the non-congested neighbors and initiates route discovery mechanism to discover a congestion free route between source and destination. This path becomes a core path between source and destination. To maintain the congestion free status, the nodes which are helping data packet transmission periodically calculate their congestion status at the node level. When a core node is noticed that it fell in to likely to congested zone and alerts to its neighbors. The predecessor core path node is aware of this situation and initiates an alternate path discovery mechanism to a destination. Finally it discovers a new congestion free route to the destination. Results: The assessment between CFR and AODV was conducted by using the Ns-2 simulator. The simulation results confirmed that the CFR improved packet delivery ratio, reduction of End to End delay and control packets. Conclusion: Our proposed technique solved the congestion problems in a network.