Performance Evaluation of AODV and OLSR with Varying Number of Nodes and Fragmentation Threshold

Abstract

Communication in Physical Sciences, 2020, 6(2): 899-909 

Authors: Obasa Mustapha Adeyink, Okunade Oluwasogo Adekunle and Osunade Seyi

Received 18 September 2020/Accepted 28 December 2020    

A Mobile Adhoc Network (MANET) is a collection of mobile devices dynamically forming a communication network without any central devices controlling it or any pre-existing network infrastructure. Frequent topology changes of MANET have generated some routing challenges. The present investigation was conducted on the impact of fragmentation threshold and node size On-demand Distance Vector (AODV) Routing Protocol, a proactive routing protocol and the Optimized Link State Routing protocol (OLSR), a reactive routing protocol. Different network scenarios of sizes 5 and 20 nodes method were used under fragmentation threshold of 256 bytes and 1024 bytes, with a trajectory to give mobility to the nodes. The Transmission Control Protocol (TCP) flavor Tahoe was used as the default TCP congestion control protocol. AODV and OLSR were evaluated based on their performance, using: Throughput, Delay, and Retransmission attempts. AODV has a better throughput over OLSR under the fragmentation threshold of 256 bytes but OLSR has a better throughput with fragmentation at 1025 bytes with node size kept constant at 5. An increase in note size from 5to 20 resulted in the AODV been better than OLSR but with fragmentation at 256 and 1024 bytes. Under the constraints defined in the simulation, the retransmission attempt in AODV displayed better performance for the larger network (20 nodes) and OLSR with fragmentation threshold at 256 bytes with a smaller network (5 nodes).