August 2013 Issue Vol.3 No.8
Abstract: Due to unstable link states and interference between neighbour nodes, routing in wireless mesh network (WMN) is much more complicated and unpredictable than wired network. As the simplest and most primitive routing metric, hop count does not always work well in WMN where routing with least hop count does not bring the best performance. Recent research shows that radio metrics, such as ETX reflect more accurately the link conditions in a mesh network in terms of delay, loss, bandwidth, and so on. The ETX metric routing method is used with a cross-layer design taking the asymmetry of a wireless link into account, in which monitoring and measurement functions provide metrics in both forward and reverse directions and captures the link state between the node and each of its neighbours. This method is applied to Ad-hoc On-demand Distance Vector (AODV) routing protocol during the route discovering operation. AODV-ETX finds the best path based on value of the ETX by sending the probe packets to find the delivery ratios in the forward and reverse directions, from source to destination and from destination to source respectively. We evaluate performance of the AODV-ETX protocol using NS-2 simulator. The results show that the AODV-ETX outperforms the original AODV, where the results show a significant reduction of delay compared to the original AODV and also the packet delivery ratio is comparable to the packet delivery ratio in the original AODV.
Keywords: AODV, ETX, internetwork, MAC, Mesh topology, Network traffic, NS-2.34, Radio nodes, X-graphs
Abstract: MANET is an temporary decentralized infrastructure less network where each node can behave like receiver and transmitter and having a permission to move any were across the network without loss the connectivity with rest of network. Message sharing is an important task of MANET, MANET have verity of routing protocol to serve massage sharing .Performance of these routing protocol depend upon collision rate ,reach ability, rebroadcasting and average latency. Message sharing scheme in MANET is categorized namely into deterministic and probabilistic schemes. This paper give an bird eye over MANET and its routing algorithms mainly probabilistic scheme for routing and also include recent research towards better performance in term of lower collision rate, battery consumption, rebroadcasting rate and higher degree of reach ability ,average latency.
Keywords: MANET, Probabilistic Algorithm, Bayesian Approach