Performance Study and Effects of Route Caching Mechanisms in On-Demand Routing Algorithms for MANET

摘要

Route caching strategy is an important part of any on-demand routing protocols to influence performance of wireless networks. Performance metrics like overhead and delay were found to vary with utilization levels of route cache for protocols like Dynamic Source Routing (DSR) and Highest Energy Routing (HER). Hence variations to these protocols are presented in this paper to improve reliability of service and reduce the effects of cache staleness and network partitions. The variation is with respect to identification of route and cache validation of errors using different techniques namely Update Route Caching (URC), Temporal Cache Validation (TCV), Negative Cache Validation (NCV) and combined cache validation (CCV). These techniques refresh cache more often than the DSR and HER thereby initiating route requests earlier, when a route still being used is broken, thus reducing peer-to-peer delay to transmit packets. The results of GloMoSim simulator validates higher cache hit percentage and reliable delivery of packets in the technique Combined Cache Validation (CCV) when in comparison to DSR and HER.