Influence of link sensing mechanism of IMEP on the performance of TORA under different mobility models

The performance evaluation of Mobile Ad Hoc Network (MANET) routing protocols is an important as well as open area of research worldwide. Temporally Ordered Routing Algorithm (TORA) is an adaptable and distributed MANET routing protocol which is dependent on the services of Internet MANET Encapsulation Protocol (IMEP) for its various necessary functions like link status detection. The incorrect link failure detection by IMEP leads to creation of congested network and initiation of avoidable route maintenance in TORA. Thus changes need to be introduced in the link sensing mechanism provided by IMEP to improve the detection of links in TORA. According to previously available research, if the maximum number of OBM retransmissions is increased, significant improvement in the performance of TORA is noticed. This modification has been implemented in this paper and performance of Enhanced TORA is evaluated under Random-Waypoint model, Manhattan-Grid mobility model and Random-Direction model using FTP traffic with 10 connections. The results are then compared with those of original TORA using various performance metrics like Packet Delivery Ratio, Average End to End Delay and Routing Overhead.