Energy Efficient Node Caching and Load Balancing Enhancement of Reactive Ad Hoc Routing Protocols

Enhancing route request broadcasting protocols constitutes a substantialpart of recent research in mobile ad-hoc network (MANET) routing. We suggest anovel approach to modify route request broadcast based on node caching. The intuitionbehind node caching is that the nodes involved in recent data packet forwarding havemore reliable information about its neighbors and have better locations (e.g., on theintersection of several data routes) than other nodes.We cache nodes which are recentlyinvolved in data packet forwarding, and use only them to forward route requests.Stopping forwarding route requests from the other nodes considerably reduces routingoverhead at the expense of possible destination missing. The suggested node cachingtechniques can be also viewed as a dynamic implementation of a connected dominatingset (CDS).We overcome the known drawback of CDS – overuse of dominating (cached)nodes – by a new load-balancing scheme.Our contributions include: (i) a new energy-efficient node caching enhancement of routerequest broadcast for reactive ad hoc routing protocols; (ii) an extensive simulationstudy in NS2 of the novel node caching enhancement of AODV (AODV-NC) showingdrastic reduction in overhead, significant improvement of the packet delivery ratio andthe end-to-end delay and overhead; (iii) an analysis of the forwarding load distributionand energy consumption, and (iv) an extensive simulation study in NS2 of thenovel AODV-NC based routing protocol with adaptive workload balancing (AODVNC-WLB) showing considerable improvement in throughput, overhead, delivery ratioand delay over the standard AODV for stressed MANETs