2012 2nd IEEE International Conference on Parallel, Distributed nd Grid Computing Metrics Improvement ofMANET Using Reactive Protocols Approach Puneet Dadral Department of Elecronics Technology, Guru Nanak Dev University, Amritsar, Punjab, India puneet6 _dadral@yahoo.co.in Rajan Vohra* Department of Elecronics Technology, Guru Nanak Dev University, Amritsar, Punjab, India sargam _lll@yahoo.co.in* Ravinder Singh Sawhney Department of Elecronics Technology, Guru Nanak Dev University, Amritsar, Punjab, India sawhney_gndu@hotmail.com Abstract- Mobile ad hoc networks (MANETs) are a collection of wireless nodes that dynamically create a wireless network among themselves without any infrastructure. Each device in a MANET is free to move independently in any direction, and will therefore change its links to other devices frequently. The objective of this paper is to evaluate the simulation of MANET reactive routing protocols that are Ad Hoc On demand Distance Vector (AODV) and Dynamic Source Routing (DSR) and temporally ordered routing algorithm (TORA) for Guru Nanak Dev University Campus environment using the High Resolution Video Conferencing application. Comparative analysis has been carried out based on the results obtained by simulations with OFDM (802.11a) and Extended Rate PHY (802.11g) physical characteristics in OPNET Modeler version 14.5. Parameters used are Throughput, End to End delay, Routing load and Media Access Delay. Kywords- MANET, DSR, AOD, RREP, RREQ, A, OPNET I. INTRODUCTION Mobile Ad hoc Networks refer to wireless networks where all network components are mobile. In MANET there is no distinction between a host and a router since all network hosts can be endpoints as well as forwarders of trafic [I]. Nodes in the network should be able to sense and discover their neighboring nodes and interact with them. Due to the limited transmission range of wireless network interfaces, multiple network hops may be needed for one node to exchange data with another across the network. Nodes in these networks carry out both network control and routing duties and thus generate both user and application traics. The nodes in the network are used to provide connectivity and services that the nodes communicate directly with one another in peer-to-peer fashion [2]. MANETS are successful in applications such as disaster recovery, conferences, emergency situations in hospitals, meetings, crowd control, and battle ields [3]. II. LITERATURE REVIEW A lot of research work has been done previously for the comparison analysis of routing protocols of MANET by means of performance parameters for the various 978-1-4673-2925-5/12/$31.00 ©2012 IEEE 73 applications and used different simulators for this purpose. M.L Sharma, Noor Fatima Rizvi [4] have worked on evaluating the performance of proactive and reactive AODV, DSR routing protocols based on trafic generators like FTP under different network scenarios and the results are varied depending upon the used raic. Results show that DSR performs better than AODV in terms of packet delivery ratio and throughput but worst in average end to end delay. While AODV shows the best performance in terms of average end to end delay and routing message overhead. The research carried by Jahangir khan et al. [5] is to extend and evaluate routing protocols AODV and DSR in order to judge MANET delay and packet delivery ratio in intermediate nodes and also to present some of the undamental routing issues when developing QoS (Quality of Service) ramework for ad hoc networks. Maashri et al. [6] analyzed the performance of DSR, AODV and OLSR routing protocols. The paper concluded that DSR has superior performance in terms of data packet delivery ratio, throughput and end to end delay at the speeds of less than 10 mls compared to AODV and OLSR. But, OLSR performed weak in the presence of a statistically self-similar trafic at high mobility especially in terms of data packet delivery ratio, overhead and delay. Also in AODV, lower end-to-end delay has been observed. Singla and P. Kakar [7] have compared the performance of AODV, TORA and DSDV protocols under both CBR and TCP traic pattern. Simulation results show that Reactive protocols perform better in terms of packet delivery ratio and average end to end delay. In our research, simulation results are evaluated for AODV, DSR and TORA reactive protocols of MANET based on OFDM (802.1Ia) and Extended Rate PHY (802.11g) physical characteristics using high resolution Video Conferencing application at high data rate of 48mbps. III. PROTOCOLS DESCIPTION A routing protocol is mainly used to discover the shortest and most eficient path during the data transmissions in MANET. Routing basically classiied in