Abstract:
In a Mobile Ad hoc Network (MANET) there isnofixed infrastructure by which routing is performed. The mobile nodes work both as routers and hosts. The absence of fixed centralized infrastructure and unpredictably varying topology in MANETs make routing andthe design of routing protocols complex and challenging issues. A lot of researches have been done on the area and different routing protocols were developed such as AODV, DSR, OLSR, TORA and others. A good understanding of their performance characteristics helps to find out and deploy appropriate protocol for a particular network scenario and do further optimizations.In most of these previous works, performance analysis were not performed based on a broad range of control variables on which the protocols are mainly optimized such as traffic loads, network size and mobility scaling. There are no adequate and comprehensive researches on the effect of each control variable on the protocols. Most of the researches were done based on constant bit rate (CBR) on NS-2 simulator. In this research the performance analysisand comparison of three popular protocols (AODV, DSR and OLSR) have been conducted using OPNET Modeler. The effect of FTP traffic load, network size and mobility variations on each of the protocols considered were analyzed. Average end-to-end delay and throughput were used as performance measurement metrics. Simulation results show that the throughput performance increases and the delay performance decreases when traffic load and network size increase in all the protocols. Mobility has no significant effect on the performance of the protocols as the network grows larger. OLSR and AODVhave overall betterperformances in terms of end-to-end delay and throughput respectively in almost all
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the scenarios considered. Reactive protocols have inconsistent and larger delay performance.
