Modified AODV for multi-constrained QoS routing and performance optimization in MANET

A mobile ad-hoc network (MANET) is a collection of self configuring mobile devices, capable of moving randomly and connected through wireless physical medium without having any fixed infrastructure. MANET technology is highly important for any kind of communications where no fixed infrastructure is available. The dynamic characteristics of MANET, has made it quite challenging to maintain connectivity and ensure Quality of Service (QoS). In this paper, AODV, a purely on demand MANET routing protocol, is enhanced to provide QoS. The route discovery process is modified to reduce the connection set up latency. In addition, QoS provision based on delay and bandwidth requirements is incorporated to ensure guaranteed performance level to the QoS sensitive applications. The enhanced protocol is called NQoS AODV. Three performance parameters: End-to-end Average Delay, Packet Delivery Ratio and Control Overhead are considered in different mobility scenarios to compare the performance of the proposed protocol with the original AODV. Hello message is used for connectivity maintenance and carrying QoS information.