Routing in mobile Ad Hoc Networks

A Mobile Ad Hoc Network (MANET) is built on the fly where a number of wireless mobile nodes work in cooperation without the engagement of any centralized access point or any fixed infrastructure. Two nodes in such a network can communicate in a bidirectional manner if and only if the distance between them is at most the minimum of their transmission ranges. When a node wants to communicate with a node outside its transmission range, a multihop routing strategy is used which involves some intermediate nodes. Because of the movements of nodes, there is a constant possibility of topology change in MANET. Considering this unique aspect of MANET, a number of routing protocols have been proposed so far. This chapter gives an overview of the past, current, and future research areas for routing in MANET. In this chapter we will learn about the following things: - The preliminaries of mobile ad hoc network - The challenges for routing in MANET - Expected properties of a MANET routing protocol - Categories of routing protocols for MANET - Major routing protocols for MANET - Criteria for performance comparison of the routing protocols for MANET - Achievements and future research directions - Expectations and realit

Routing Protocol Performance Evaluation for Mobile Ad-hoc Networks

Currently, MANETs are a very active area of research, due to their great potential to provide networking capabilities when it is not feasible to have a fixed infrastructure in place, or to provide a complement to the existing infrastructure. Routing in this kind of network is much more challenging than in conventional networks, due to its mobile nature and limited power and hardware resources. The most practical way to conduct routing studies of MANETs is by means of simulators such as GloMoSim. GloMoSim was utilized in this research to investigate various performance statistics and draw comparisons among different MANET routing protocols, namely AODV, LAR (augmenting DSR), FSR (also known as Fisheye), WRP, and Bellman-Ford (algorithm). The network application used was FTP, and the network traffic was generated with tcplib [Danzig91]. The performance statistics investigated were application bytes received, normalized application bytes received, routing control packets transmitted, and application byte delivery ratio. The scenarios tested consisted of an airborne application at a high (26.8 m/s) and a low speed (2.7 m/s) on a 2000 m x 2000 m domain for nodal values of 36, 49, 64, 81, and 100 nodes, and radio transmit power levels of 7.005, 8.589, and 10.527 dBm. Nodes were paired up in fixed client-server couples involving 10% and 25% of the nodes being V111 clients and the same quantity being servers. AODV and LAR showed a significant margin of performance advantage over the remaining protocols in the scenarios tested

Ad hoc network routing

An ad hoc network is composed of nodes that may move arbitrarily and without the support of a stationary infrastructure. The dynamic nature of ad hoc networks makes it very challenging to realize routing and deliver data packets efficiently. This article discusses the challenges of ad hoc network routing, surveys existing routing algorithms, and provides a comparison of these algorithms.published_or_final_versio

Effective Route Maintenance and Restoration Schemes in Mobile Ad Hoc Networks

This study proposes a location-based hybrid routing protocol to improve data packet delivery and to reduce control message overhead in mobile ad hoc networks. In mobile environments, where nodes move continuously at a high speed, it is generally difficult to maintain and restore route paths. Therefore, this study suggests a new flooding mechanism to control route paths. The essence of the proposed scheme is its effective tracking of the destination’s location based on the beacon messages of the main route nodes. Through experiments based on an NS-2 simulator, the proposed scheme shows improvements in the data packet delivery ratio and reduces the amount of routing control message overhead compared with existing routing protocols such as AODV, LAR, ZRP and AODV-DFR

Routing in Large Scale tactical mobile ad hoc Networks

The current Transformation of the military networks adopts the MANET as a main component of the tactical domain. Indeed, a MANET is the right solution to enable highly mobile, highly reactive and quickly deployable tactical networks. Many applications such as the Situational Awareness rely on group communications, underlying the need for a multicast service within the tactical environment where the MANET is employed as a transit network. The purpose of this thesis is to study the setting up of an optimal multicast service within this tactical environment. We firstly focus on defining the protocol architecture to carry out within the tactical network paying particular attention to the MANET. This network is interconnected with different types of networks based on IP technologies and implementing potentially heterogeneous multicast protocols. The tactical MANET is supposed to be made of several hundred of mobile nodes, which implies that the scalability is crucial in the multicast protocol architecture choice. Since the concept of clustering proposes interesting scalability features, we consider that the MANET is a clustered network. Thereby, we define two multicast routing protocols adapted to the MANET: firstly STAMP that is in charge of the multicast communications within each cluster and secondly SAFIR that handles multicast flows between the clusters. These two protocols that can be implemented independently, act in concert to provide an efficient and scalable multicast service for the tactical MANET. Then, we study the interoperability of these multicast protocols employed within the MANET with those employed in the heterogeneous networks that it is interconnected with in order to guarantee end-to-end seamless multicast services to users. Finally, since the multicast protocols proposed in this thesis rely on underlying unicast routing protocols, we propose, in the last chapter, a scalable unicast routing protocol based on OLS

Efficient and highly scalable route discovey for on-demand routing protocols in ad hoc networks

This paper presents a number of different route discovery strategies for on-demand routing protocols, which provide more control to each intermediate node make during the route discovery phase to make intelligent forwarding decisions. This is achieved through the idea of selfselection. In self-selecting route discovery each node independently makes Route Request (RREQ) forwarding decisions based upon a selection criterion or by satisfying certain conditions. The nodes which do not satisfy the selection criterion do not rebroadcast the routing packets. We implemented our self-selecting route discovery strategies over AODV using the GloMoSim network simulation package, and compared the performance with existing route discovery strategies used in AODV. Our simulation results show that a significant drop in the number of control packets can be achieved by giving each intermediate node more authority for self-selection during route discovery. Furthermore, a significant increase in throughput is achieved as the number nodes in the network is increased

Securing Fisheye State Routing Algorithm Against Data Packet Dropping by Malicious Nodes in MANET.

Mobile Ad Hoc Network (MANET) is an emerging area of research in the communication network world. As the MANET is infrastructure less, it is having dynamic nature of arbitrary network topology. So, it needs set of new networking strategies to be implemented in order to provide efficient end to end communication. These (MANET) networks have immense application in various fields like disaster management, sensor networks, battle field etc. Many routing protocols have been proposed in MANET among which Fisheye State Routing (FSR) protocol scales well in large network. Security in MANET is a very difficult problem to incorporate without degrading the performance of the protocol. A performance comparison of different routing protocols has been given here and this research narrows down to security related issues associated with FSR. The attacks on the MANET can be broadly divided into 2 types as active attacks and passive attacks. The proposed scheme deals with minimizing passive attacks which causes dropping of data packets by the selfish nodes or malicious nodes. The idea is based on modifying the traditional Dijkstra’s Algorithm which computes shortest route to all destinations from a source. The actual FSR algorithm considers the link cost between two nodes as 1 if one node comes in the radio range of another. In our proposed scheme the weight has been assigned depending upon the number of times the next node has behaved maliciously or selfishly. Here we have proposed one scheme which uses a two hop time stamp method to detect a malicious node and the Dijkstra’s shortest path algorithm has been modified to re compute the optimal paths to destination and hence, to minimize the data packet dropping by malicious nodes in the network