Influence of Routing Protocols in Performance of Wireless Mobile Adhoc Network

An ad hoc network is a collection of wireless mobile nodes dynamically forming a temporary network without the use of any existing network infrastructure or centralized administration. A number of routing protocols such as Dynamic Source Routing (DSR), Ad Hoc on-Demand Distance Vector Routing (AODV) and Destination-Sequenced Distance-Vector (DSDV) have been implemented. In this paper, an attempt has been made to compare the performance of two prominent on-demand reactive routing protocols for mobile ad hoc networks: DSR and AODV, along with the traditional proactive DSDV protocol. A simulation model with Media Access Control (MAC) and physical layer models are used to study interlayer interactions and their performance implications. The On-demand protocols, AODV and DSR perform better than table-driven DSDV protocol. Although DSR and AODV share similar on-demand behavior, the differences in the protocol mechanism can lead to measurable amount of variation in performance. A variety of workload are characterized by mobility, load and size of the ad hoc network in a given scenario were simulated which helped to analyze the performance. The main reason for degradation in performance as a result of node mobility is due to traffic control overhead required for maintaining accurate routing tables in case of table-driven protocols and maintaining routes in on-demand protocols [1]. We quantify the effect of node mobility and message length on the Bit Error Rate (BER) of an average multi-hop route using a recently developed communication-theoretic framework for adhoc wireless network [2]. We study the network performance such as throughput, delivery ratio, and end-to-end delay when position-based routing is used. Also node mobility and position error affect the performance. The variation in performance differentials are analyzed by use of varying simulation time. These simulations are carried out using NS-2 simulator. The results presented in this work illustrate the importance in carefully evaluating and implementing routing protocols in an ad hoc environment.