Research On Routing Algorithm And Related Technologies In Wireless Ad Hoc Network

Wireless Mobile Ad Hoc Network (MANET) is a special temporary wireless networkwithout infrastructure. This type of network has characteristics, such as dynamic and finiteenergy supply. Dynamic topology changes, node mobility and channel fading have a greatinfluence on the performance of networks. Unlike some other networks, like wired networksand wireless cellular networks, wireless ad hoc networks does not have fixed infrastructure,whose nodes are randomly put into a space (e.g., thrown from an aircraft). Wireless nodescan communicate with each other through establishing a communication network in anenergy efficient manner.In Mobile Ad Hoc Network, each node acts as both traffic originators and forwarders inorder to construct a multi-hop network. Out-of-range nodes can be reached by routingprocess, which is a challenging task since the constraints of bandwidth and battery power.Wireless nodes are usually powered by batteries with limited power. However, it is verydifficult and even impossible to recharge or change the batteries. This defect motivated manyresearchers to design wireless ad hoc networks with higher energy efficient topologies andmethods.Routing is the fundamental problem for Wireless Ad hoc networks, although theproblem has been extensively studied in the past few years, the existing solutions havedeficiencies in e ciency, scalability, robustness, complexity and etc. Therefore, the rationaldesign of routing protocols is very important for Wireless Mobile Ad hoc network.The main contributions of this dissertation are as following.1. There are lots of devices with different power in Wireless Mobile Ad hoc network.The issue may have little influence in a wired network. However, in the wireless network,that would become a serious problem. Most of the traditional routing protocols assume thatthe link is symmetric, but we found that heterogeneity network performance would be severely affected. We design new routing protocols that employ adaptive technique to theMANET routing protocols. In the new routing protocol, nodes can determine whether toforward packets or not by sensing the power. By avoiding dependence on periodic beaconing,this method requires low overhead and delay.2. Since Wireless Ad hoc networks is an autonomous collection of mobile users thatcommunicate over relatively bandwidth constrained wireless links. As the nodes are mobile,the network topology may change rapidly and unpredictably over time. As each node is freeto join and leave the network in a non-deterministic way, it is important to find a route,which can send packets in such a dynamic networks. This is particularly important when thenumber of nodes becomes larger in the network. According the situation, we propose arouting protocol based on Mean Field Equilibrium in Wireless Ad Hoc network, in whicheach node reacts to only the long run average state of other nodes, and do not require nodesto know each other’s exact states. It can simplify the compute process by using standardsolution of Markov perfect equilibrium. It can be shown that mean field equilibrium isapproximately Markov perfect equilibrium as the number of players grows large. Oursimulation show the comparison of protocols AODV and MFEA, particularly averageend-to-end delay, packet delivery ratio and normalized overhead, the consequences indicatethe methodology works well and even in dense wireless ad hoc networks.3. Stateless location-based routing schemes have been proposed to avoid complex routediscovery and maintenance, whereby nodes make routing decisions based solely on theknowledge of their location, the location of their neighbors, and the location of thedestination. An efficient route finding approach for mobile ad hoc network is presented inthis paper，it is an adaptive routing protocol that has a tradeoff between transmission powerand hop count for wireless ad hoc networks. When a node works on route finding process, itsends out multiple copies of HOP messages to increase the likelihood that more nodes cancommunicate each other by a shortest path, and the node who has received route requestmessage compares itself power with the threshold power value, then according to thediscriminating algorithms to select a reasonable route hop number. Simulation consequencesindicate that the proposed protocol can deliver better performances with respect to energyconsumption and end-to-end delay. This algorithm is an effective solution to the wireless Adhoc network through reasonably selected path to reduce the whole network energyconsumptions and average delay.