A mobile ad hoc network consists of wireless hosts that may move often. Movement of hosts results in a change in routes, requiring some mechanism for determining new routes. Several routing protocols have already been proposed for ad hoc networks. This paper suggests an approach to utilize location information (for instance, obtained using the global positioning system) to improve performance of routing protocols for ad hoc networks. By using location information, the proposed Location-Aided Routing (LAR) protocols limit the search for a new route to a smaller “request zone ” of the ad hoc network. This results in a significant reduction in the number of routing messages. We present two algorithms to determine the request zone, and also suggest potential optimizations to our algorithms. 1

We propose a new geometric spanner for static wireless ad hoc networks, which can be constructed efficiently in a localized manner. It integrates the connected dominating set and the local Delaunay graph to form a backbone of the wireless network.

This paper investigate fault tolerance for wireless ad hoc networks. We consider a large-scale of wireless networks whose nodes are distributed randomly in a unit-area square region. Given n wireless nodes V , each with transmission range rn , the wireless networks are often modeled by graph G(V,rn ) in which two nodes are connected if their Euclidean distance is no more than rn .

Many routing protocols have been proposed for wireless ad hoc networks, and most of them are based on some variants of flooding. Thus many routing messages are propagated through the network unnecessarily despite various optimizations. Gossip based routing method has been used and re-investigated to reduce the number of messages in both wired networks and wireless ad hoc networks. However, the global gossiping still generates many unnecessary messages in the area that could be far away from the line between sender node and receiver node. We propose a regional gossip approach, where only the nodes within some region forward a message with some probability, to reduce the overhead of the route discovery in the network. We show how to set the forwarding probability based on the region and the network density both by theoretical analysis and by extensive simulations. Our simulations show that the number of messages generated using this approach is much less than the simple global gossiping method, which already saves many messages compared with global flooding. We expect that the improvement should be even more significant in larger networks.

Location-Aided Routing (LAR) [14] algorithm is an approach to utilize location information for mobile hosts, with the goal of decreasing routing-related overhead in mobile ad hoc networks. A number of optimizations are possible to improve performance of the basic LAR protocols. This paper mainly focuses how the basic operation of LAR can be improved by applying those optimization schemes. 1 Introduction The issue of developing efficient routing algorithms is a challenging problem in the area of mobile ad hoc networking (MANET). Many different protocols have been proposed to achieve a given level of routing performance for MANET [1, 2, 4, 5, 6, 8, 9, 14, 15, 18, 19, 20, 22, 23]. Among those protocols, Location-Aided Routing (LAR) algorithms we proposed [11, 12, 14] attempt to reduce routing discovery overhead incurred with some flooding based approaches, such as Dynamic Source Routing (DSR) [9, 10] and Ad hoc On demand Distance Vector routing Research reported is supported in part b...

Ad Hoc Networks consists of set of mobile nodes forming spontaneous network. There is a need for an efficient routing protocol for Ad Hoc networks over the years. Bandwidth utilization and node power consumption are two important factors in wireless transmissions. This paper presents simulation model of new routing protocol ARRP (Azimuth Restricted Routing Protocol). ARRP uses position information of nodes and azimuth angle to define a range to restrict the broadcast of RREQ packets rather than flooding the entire network. This will reduce routing overhead in route discovery phase, saving wireless bandwidth and node power. Simulation of this protocol is done using Network Simulator