The Dynamic Counter-Based Broadcast for Mobile Ad hoc Networks

摘要: Broadcasting is a fundamental operation in mobile ad hoc networks (MANETs) crucial to the successful deployment of MANETs practice. Simple flooding most basic broadcasting technique where each node rebroadcasts any received packet exactly once. Although ideal for its simplicity and high reachability it has critical disadvantage that tends generate excessive collision consumes medium by unneeded redundant packets. A number schemes have been proposed alleviate drawbacks while maintaining reasonable level reachability. These mainly fall into two categories: stochastic deterministic. While former employs simple yet effective probabilistic principle reduce latter typically requires sophisticated control mechanisms broadcast. The key danger with aim broadcasts retransmissions they often do so at expense threshold which can be required many applications. Among schemes, counter-based broadcasting. In this scheme are inhibited criteria related duplicate packets received. For achieve optimal reachability, fairly stable known nodal distributions. However, general, MANETs‟ topology changes continuously unpredictably over time. Though was among earliest suggestions problems associated broadcasting, there few attempts analyse depth performance such an approach MANETs. Accordingly, first part research, Chapter 3, sets baseline study analysing under various network operating conditions. The second part, 4, establish claim alleviating existing dynamically setting values according local neighbourhood density improves overall efficiency. This done through implementation analysis Dynamic Counter-Based (DCB) scheme, developed as work. shows clear benefit terms of average rate, saved end-to-end delay, reachability. The third 5, evaluates dynamic counting tests some approximately realistic scenarios. examples chosen from rapidly developing field Vehicular Ad Networks (VANETs). studied metropolitan settings, involving nodes moving streets lanes speed direction constraints. Two models considered implemented: assuming unobstructed open terrain; other taking account buildings obstacles. While vital MANET routing protocols, investigation broadcast tended focus on little examination impact those specific applications, route discovery protocols. fourth 6, On-demand Distance Vector (AODV) protocol mechanism based dynamic-counting. AODV widely accepted research community standardised IETF working group. That said, protocols would expected interact similar manner. analysed three mechanisms, notably flooding, counting. Results noticeable advantage, metrics achieved using compared or traditional flooding. In summary, range conditions applications; demonstrates when predecessors wide conditions.