Revisiting Gossip-Based Ad-Hoc Routing

The Ad-Hoc networks are autonomous and infrastructure-less networks that provide flexibility to network nodes to connect and disconnect at any time. Routing protocol is a crucial part in the changeable topology network. DSDV, DSR and AODV are the most typical basic protocols for wireless Ad-Hoc networks. In this paper, it interprets and compares these three typical routing protocols using NS-2 simulator. It analyzes these three protocols in several aspects such as packet loss rate, route cost, average end-to-end delay and packet delivery fraction through simulations using Network Simulator in varying network conditions including the number of nodes, maximum moving speed of mobile node, maximum number of connections, node pause time, data rate and node moving range. Performance analysis of simulation results shows that each protocol has its own best suitable scene, so one can choose the optimal protocol under different scenarios according to the simulation results.

Wireless ad-hoc networks are collections of wireless nodes having no predefined infrastructure. Most of the existing routing protocols for wireless ad-hoc networks use the shortest path or minimum distance path to the destination. However, the shortest path routing does not provide a good balance of the traffic load among all nodes. When many users utilize the shortest paths, some nodes become highly congested and become what is known as hotspots. These hotspots degrade the performance of wireless ad-hoc networks by creating long queuing and contention delays. This paper investigates the effects of shortest path routing on the network by varying different network parameters. A load distributed path routing is also proposed to enhance the performance of shortest path routing. Matlab simulations show that the load distributive routing provides 35% and 44% less contentions in a 20-node and 30-node network respectively, when compared to shortest path routing.

This paper considers the problem of self-diagnosis of wireless ad-hoc networks using the comparison approach. In this approach, a MANET consists of a collection of n independent heterogeneous mobile hosts interconnected via wireless links, and it is assumed that at most σ of these mobile hosts are faulty. In order to diagnose the state of the wireless ad hoc network, tasks are assigned to pairs of mobiles and the outcomes of these tasks are compared. The agreements and disagreements among mobiles are the basis for identifying the faulty mobiles. The comparison approach is believed to be one of the most practical diagnosis approaches. We describe a new distributed self-diagnosis protocol for wireless ad hoc networks that is able to identify hard and soft faults in a finite amount of time. We then analyze the time and communication complexities of wireless ad hoc networks and show that it performs better, from a communication complexity viewpoint, than the existing protocols.

A peer-to-peer file search and download protocol for wireless ad-hoc networks

This paper presents an overlay based Byzantine tolerant broadcast protocol for wireless ad-hoc networks. The use of an overlay results in a significant reduction in the number of messages. The protocol overcomes Byzantine failures by combining digital signatures, gossiping of message signatures, and failure detectors. These ensure that messages dropped or modified by Byzantine nodes will be detected and retransmitted and that the overlay will eventually consist of enough correct processes to enable message dissemination. An appealing property of the protocol is that it only requires the existence of one correct node in each one-hop neighborhood. The paper also includes a detailed performance evaluation by simulation.

CF-MAC is an energy efficient collision-free MAC protocol for wireless ad-hoc networks, based on the theory of Balanced Incomplete Block Design (BIBD). It has been originally designed considering energy saving as primary aim. In this paper, using computer simulations, its ability to handle voice calls has been evaluated. Specifically, the Mean Opinion Score and the Cumulative Distribution Function of the one way packet delay have been analyzed, for various protocol parameters and network scenarios. Moreover, a comparison between CF-MAC and classical 802.11 DCF access function has been proposed. Simulation results have shown that by properly selecting protocol parameters, CF-MAC can effectively support VoIP calls.

We introduce WRP-Lite, which is a table-driven routing protocol that uses non-optimal routes, and compare its performance with the performance of the dynamic source routing (DSR) protocol, which is an on-demand routing protocol for wireless ad-hoc networks. We evaluate the performance of WRP-Lite and DSR for varying degree of mobility and traffic in a 20-node network. The performance parameters are end-to-end delay, control overhead, percentage of packets delivered, and hop distribution. We show that WRP-Lite has much better delay and hop performance while having comparable overhead to DSR.

Complete-exchange multicasting is quite useful for numerous applications. We explicate a load-balanced complete-exchange multicast protocol (LCM), based on passive clustering, for wireless ad-hoc networks. From a logical viewpoint, LCM constructs multiple cluster structures to balance the traffic loads among all group members. It further avoids overloading of nodes or traffic congestion on the route. In LCM, an innovative scheme is devised to deal with the scenario in which a node plays different roles for different cluster structures. Simulation results show that LCM not only preserves all the advantages of passive clustering, but also performs very efficiently in complete-exchange multicasting. Consequently, LCM is really a feasible solution for load-balanced complete-exchange multicasting, especially for dense networks.

Development of applications and protocols for wireless ad-hoc networks has always been a challenge. Spe- cific characteristics such as frequent topology changes due to nodes moving around, popping up or being turned off, need to be considered from the earliest stages of develop- ment. Since testing and evaluation using genuine wireless devices is both expensive and highly impractical, other tools need to be used in the development phase. Simulators give a very detailed model of lower layers' behaviors, but code often needs to be completely rewritten in order to be used on actual physical devices. Emulators present a trade-off be- tween real test beds and simulators, providing a virtual wireless network at the lowest layers, and yet allowing real code to be run on the higher layers. In this paper, we pre- sent such an emulation platform, called NEMAN, that al- lows us to run a virtual wireless network of hundreds of nodes on a single end-user machine. NEMAN has shown to be an important and very useful tool during development of different applications and protocols for our project, includ- ing a key management protocol and a distributed event noti- fication service.

Ad hoc mobile networks are composed of mobile nodes communicating through wireless medium, without any fixed backbone infrastructure. In these networks, Congestion occurs in any intermediate nodes when data packets travel from source to destination and they incur high packet loss and long delay, which cause the performance degradations of a network. This paper presents the early detection congestion and control routing protocol for wireless Ad-hoc networks called as EDAODV. EDAODV detects congestion at a node level by calculating queue_status value and finding congestion status. Based on a congestion status, EDAODV utilizes the non-congested predecessor and successor nodes of a congested node and initiates route finding process bi-directionally to find alternate non-congested path between them for transmitting data. The process finds more non-congested alternate paths and chooses a best single path for transmitting data.

TDMA-based Medium Access Control (MAC) protocols for ad hoc networks achieve good performances at high loads and high network densities. Nevertheless, their slot assignment techniques infer inefficient and unfair resources exploitation due to free slots appearance and slot assignment regardless the effective needs. This paper tackles these disadvantages by performing a slot-by-slot reservation mechanism. It results a new MAC protocol, called OSTR (One shot Slot TDMA-based Reservation). OSTR operates in a distributed and slotted environment. It is a topology-based and dynamic frame size-based protocol. OSTR leads to a slower frame size increase. Experimental results show that OSTR achieves a shorter frame size even with high densities inferring a better channel utilization.

Mobile Ad-hoc Network (MANET) has emerged as the self organized wire less interconnection for the various applications in random topology. As most of the multimedia applications require strict QoS guarantee during the communication between a single source and multiple destinations. How ever, achieving reliable multicast transmission in MANET is crucial due to the dynamic network topology caused by the node mobility. This gives rise to the need for an efficient multicast routing strategy. This paper proposes a novel scheme PBMRP-BR (position-based Multicast Routing Protocol for Ad-hoc Network Using Backpressure Restoration) for efficient transmission of multimedia applications in Ad-hoc Network, which provides priorities for routing based on Distance of path, Load at the node (ie, traffic) and queue length at the node(ie, bandwidth). It also keeps the path information including bandwidth resources of each node for routing decisions. The problem of the link failure in the channel during the call in progress thus lead in the degradation of the QoS (Quality of Service).To deal this we are using a Backpressure Technique The simulation results shows that the proposed algorithm is able to find a better solution, fast convergence speed and high reliability. The simulation results shows the proposed PBMRP-BR protocol achieve the above objectives and gives the batter results than previous schemes like DSR for the maintenance of overheads and the path reliability. Our proposed scheme will improve the bandwidth utilization by reducing the congestion in the Adhoc wireless network.

Ad hoc networks are useful in many application areas. Security is important but it is a challenging issue due to ad hoc network’s characteristics such as lack of infrastructure, communication over wireless medium, and node mobility. In this paper we present a secure multicast routing protocol for ad hoc networks. The proposed protocol makes it possible for a node to create a new multicast group and join or leave an existing group securely. It also includes a mechanism for detecting and repairing broken links securely. In addition to securely exchanging multicast packets, this paper addresses the problem of securely building and maintaining multicast trees in ad hoc networks. Moreover, the protocol guards against attacks from authorized but misbehaving nodes as well as unauthorized nodes.

Ad Hoc network is one of the popular wireless multi-hop networks. Nodes or Users in Ad Hoc network can move randomly and freely to maintain communication without the control of the fixed infrastructure. Due to the limited transmission power and wireless coverage of the terminal, if two terminals that are beyond their respective transmission radius need communicate, they must use other intermediate or relay nodes for packet forwarding, so that a wireless Ad Hoc network is formed among these nodes. In this paper, the current state-of-the-art multipath routing protocols for Ad Hoc networks are reviewed. Particularly, the pros and cons of them are analyzed. Finally, they are summarized and compared.

Recent development has a tremendous growth in the ad-hoc wireless networks. Ad-hoc wireless networks are dynamic topology networks organized by a collection of mobile nodes that utilize multi-hop radio relaying and are capable of operating without the support of any fixed infrastructure. Ad-hoc wireless networks are very useful in emergency operations, collaborative and distributed computing and military applications. Multicasting plays an important role in the ad-hoc wireless networks, where nodes form groups to carry out certain tasks that require point-to-multipoint and multipoint-to-multipoint voice and data communication. The biggest challenge in the ad-hoc wireless networks is to find an optimized path between the two nodes. In this paper, we present an ant colony based metaheuristic multicast routing protocol for ad-hoc wireless networks, in that we analyzed the performance of dynamic core based multicast routing protocol (DCMP). This approach maps the solution capability of swarm intelligence to mathematical and engineering problems. The DCMP is highly adaptive, efficient and scalable. The performance of these protocols has been examined under realistic scenarios using NS 2, the network simulator tool. Performance has been analyzed for the metrics packet delivery ratio and control overheads with the multicast routing protocol. The proposed ant colony based routing protocol reduce the overheads in routing.