Buffer Management And Auxiliary Routing In AODV

A mobile ad hoc network (MANET) is a collection of wireless mobile nodes with network interfaces that may form a temporary network without the aid of any established infrastructure or centralized administration. They are often set up on temporary basis for a particular purpose over a period of time. MANET has found applications in every day communication needs of organizations, especially in conferencing. Due to the ad hoc nature of MANET, resources are in constant state scarcity. This problem is more acute where applications using audio and video streaming require large bandwidth for effective operation. This put a further constraint on the already constrained network.This thesis proposes an algorithm, Fly Over Algorithm (FOVA), which is aimed at improving the performance of the AODV algorithm with respect to the above mentioned problem. The choice of the AODV protocol over the other existing ad hoc protocols was due to the following reasons:AODV requires the least modification for the implementation of FOVA in comparison with the other protocols discussed such as DSR and TORA.It requires a relatively lower overhead and has a good bandwidth and energy conservation.It is a popular protocol.The algorithm basically makes a slight modification to the way AODV operates by improving the buffer management and preventing packets from being dropped due to buffer overflow. The algorithm monitors the buffer level at the nodes and reroutes traffic through a backup routing system to ease the congestion at respective nodes. Congestion is assumed where the buffer approaches a threshold value which subsequently triggers the alternative route routing.The modifications will be evaluated through a series of simulations carried out in the NS2environment using various scenarios such as varied mobility levels, high and low traffic. The simulations will include the added constraint of several sources targeting a single destination in order to further demonstrate the full effect of the Fly Over Algorithm (FOVA). The results show a substantial improvement in the performance of AODV. Especially good results have been obtained for packet delivery rate and end-to-end delay.