Improvement of DSR routing protocol using TTL-based scheme in Mobile Ad Hoc Networks

Rapid change in network topology due to mobility is one of the challenges in Mobile Ad hoc Network (MANET) routing, which poses a number of problems. The protocols must be able to adapt to the unpredictable dynamic topology. This study investigates the conventional DSR and DSDV routing protocol with the aim of improving DSR routing protocol using TTL-based scheme. The preliminary investigation showed that DSDV outperformed DSR most especially when the nodes moved at high speed, which was due to inability of the DSR to repair a broken link locally and lack of any mechanism to control the freshness of routes when there are multiple options. A new mechanism, DSR_TTL was proposed in order to improve the performance of conventional DSR. The analysis was based on the small network size with constant and variable speed. The results of the study indicated that a medium number of TTL revealed a high performance for the metrics used for the study. Therefore, with all default parameters unchanged as in conventional DSR protocol, the new TTL value was set for the proposed protocol. The results have shown that the proposed protocol generally improved the network throughput and reduced the total overhead.