A wireless multi-hop ad hoc network consists of a collection of nodes, which can communicate without any fixed base stations or networking infrastructure. Multi-hop ad hoc networks are ideally suited in areas such as sensor networking, community networking and networking used in emergency situations. Since transmission is wireless and nodes could be mobile, ad hoc networks bring about new chall...

This thesis contributes toward the design of a quality-of-service (QoS) aware network layer for wireless ad hoc networks. With the lack of an infrastructure in ad hoc networks, the role of the network layer is not only to perform multihop routing between a source node and a destination node, but also to establish an end-to-end connection between communicating peers that satisfies the service le...

Ad hoc networks are multi-hop wireless networks where mobile devices communicate using a shared, low power, low bandwidth channel without any wired infrastructure: each node acts also as a router of its neighbors. Ad hoc networks protocol design is still a new and growing research area; there currently is an IETF Working Group working on the definition of a standard for such networks. Various p...

in this paper, an efficient fault-tolerant routing algorithm for mobile ad-hoc networks (manets) is presented. the proposed algorithm increases the network fault-tolerance using natural redundancy of ad-hoc networks. this algorithm is carried out in two stages; 1) the selection of backup nodes 2) the selection of backup route(s). in the first stage, the proposed algorithm chooses nodes with the...

Ab8tmct-A mobile ad-hoc network is composed of only mobile nodes, which are distributed dynamically, without any wired backbone or centralized entities. Each terminal in the mobile ad-hoc network also has the role of the router, but the frequent changes of the terminal positions induce the waste of time, energy and computing power for updating the routing table with the paging, and also may pro...

Mobile ad-hoc networks pose real difficulty in finding the multihop shortest paths because of continuous changing positions of the nodes. Traditional ad-hoc routing protocols are proposed to find multi-hop routes based on shortest path routing algorithms, which cannot effectively adapt to time-varying radio links and network topologies of Ad-hoc networks. In this paper we proposed an enhanced r...

Efficient communication between nodes in ad-hoc networks can be established through repeated cluster formations with designated clusterheads. In this context minimum d-hop dominating set problem was introduced for cluster formation in ad-hoc networks and is proved to be NP-complete. Hence, an exact solution to this problem for certain subclass of graphs (representing an ad-hoc network) can be b...

This paper presents an analytical model based upon discrete time Markov chain analysis of receiver-initiated protocols for multi hop Ad hoc networks. Three-way receiver initiated (RTR-DATA-ACK) scheme for collision avoidance in Ad hoc networks has many protocols with it. In the proposed model, the nodes are randomly distributed according to a twodimension Poisson distribution with density λ. Fo...

Wireless ad hoc networks have very limited network resources and are thus susceptible to attacks that focus on resource exhaustion, such as the injection of junk packets. These attacks cause serious denial-of-service via wireless channel contention and network congestion. Although ad hoc network security has been extensively studied, most previous work focuses on secure routing, but cannot prev...

The medium access control (MAC) protocol is the main element which determines the system performance in wireless local area networks. The MAC technique of the IEEE 802.11 protocol is called Distributed Coordination Function (DCF). In IEEE 802.11 Wireless Local Area Networks (WLANs), network nodes experiencing collisions on the shared channel need to backoff for a random period of time, which is...