Performance Analysis and Comparison of Ad Hoc Routing Protocols AODV and OLSR on Video Conferencing using OPNET Simulator

ABSTRACT: The use of devices with wireless technologies such as Laptops and mobile phones are very popular. These devices influence the use of wireless networks such as ad hoc networks. Mobile ad hoc network (MANET) is a group of devices that are connected to each other by wireless links without any centralized controlling or infrastructure. Nodes (devices) of this network are changing their locations, and also the number of nodes may change during the time. Therefore, the topology type of this network is known as dynamic. Nodes in a dynamic topology communicate with each other using routing protocols. Routing protocols are responsible for finding a path between nodes. These protocols have a significant role for the total performance of the ad hoc networks. Routing protocols of ad hoc networks are divided into the following; proactive, reactive and hybrid routing protocols. Different types of routing protocols for ad hoc networks were improved by network designers and researchers to enhance the performance of ad hoc networks by finding the shortest and efficient route establishment between two nodes for message delivery. To evaluate and compare the performance of routing protocols, a number of performance metrics are used. Each of these methods has its own properties and is suitable for a specific application type. In this study, two well-known ad hoc routing protocols, Ad hoc On-demand Distance Vector (AODV) and Optimized Link State Routing (OLSR), were analysed and compared according to their performance using a video conference application. Interactive video conferencing was chosen as an application in this study because of the increasing popularity of multimedia and real time applications by the users of ad hoc networks recently. Routing protocols are analysed with respect to the following metrics; number of hops per route, route discovery time, routing traffic sent and routing traffic received. For comparison among the mentioned protocols, metrics were used that are important for video conference applications, namely which are packet delay variation, packet end-to-end delay and normalized routing load. OPNET simulator version 17.1 is used to model and simulate ad hoc networks. The results of experimental simulations show that OLSR has better performance in packet delay variation. With OLSR protocol, the time that is required to transfer a packet from source to destination is less than the time taken by AODV. AODV has less (better) normalized routing load than OLSR in high density networks. In low density network, AODV is again better when a few nodes are communicating. On the other hand, Normalized routing load of OLSR is getting down compared with AODV when the number of communicating nodes are increasing. Keywords: Ad hoc networks, routing protocols, AODV, OLSR, simulation, performance metrics, OPNET simulator. …………………………………………………………………………………………………………………………