Nodes in mobile ad hoc networks communicate with one another via packet radios on wireless multihop links. Because of node mobility and power limitations, the network topology changes frequently. Routing protocols therefore play an important role in mobile multihop network communications. A trend in ad hoc network routing is the reactive on-demand philosophy where routes are established only when required. Most of the protocols in this category, however, use a single route and do not utilize multiple alternate paths. We propose a scheme to improve existing on-demand routing protocols by creating a mesh and providing multiple alternate routes. Our algorithm establishes the mesh and multipaths without transmitting any extra control message. We apply our scheme to the Ad-hoc On-Demand Distance Vector (AODV) protocol and evaluate the performance improvements by simulation.

AODV-BR: backup routing in ad hoc networks

If you want to get Handbook of Internet Computing pdf eBook copy write by good Handbook of Wireless Networks and Mobile Computing Google Books. Mobile Computing General. Handbook of Algorithms for Wireless Networking and Mobile Computing by Azzedine Boukerche (Editor). Call Number: TK 5103.2. CITS4419 Mobile and Wireless Computing software projects related to wireless networks, (2) write technical reports and documentation for complex computer.

Handbook of wireless networks and mobile computing

The use of on-demand techniques in routing protocols for multi-hop wireless ad hoc networks has been shown to have significant advantages in terms of reducing the routing protocol's overhead and improving its ability to react quickly to topology changes in the network. A number of on-demand multicast routing protocols have been proposed, but each also relies on significant periodic (non-on-demand) behavior within portions of the protocol. This paper presents the design and initial evluation of the Adaptive Demand-Driven Multicast Routing protocol (ADMR), a new on-demand ad hoc network multicast routing protocol that attemps to reduce as much as possible any non-on-demand components within the protocol. Multicast routing state is dynamically established and maintained only for active groups and only in nodes located between multicast senders and receivers. Each multicast data packet is forwarded along the shortest-delay path with multicast forwarding state, from the sender to the receivers, and receivers dynamically adapt to the sending pattern of senders in order to efficiently balance overhead and maintenance of the multicast routing state as nodes in the network move or as wireless transmission conditions in the network change. We describe the operation of the ADMR protocol and present an initial evaluation of its performance based on detailed simulation in ad hoc networks of 50 mobile nodes. We show that ADMR achieves packet delivery ratios within 1% of a flooding-based protocol, while incurring half to a quarter of the overhead.

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Adaptive demand-driven multicast routing in multi-hop wireless ad hoc networks

Ad-hoc networks are a key in the evolution of wireless networks Ad-hoc networks are typically composed of equal nodes, which communicate over wireless links without any central control Ad-hoc wireless networks inherit the traditional problems of wireless and mobile communications, such as bandwidth optimisation, power control and transmission quality enhancement In addition, the multi-hop nature and the lack of fixed infrastructure brings new research problems such as configuration advertising, discovery and maintenance, as well as ad-hoc addressing and self-routing Many different approaches and protocols have been proposed and there are even multiple standardization efforts within the Internet Engineering Task Force, as well as academic and industrial projects This chapter focuses on the state of the art in mobile ad-hoc networks It highlights some of the emerging technologies, protocols, and approaches (at different layers) for realizing network services for users on the move in areas with possibly no pre-existing communications infrastructure

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Mobile ad hoc networks

Advances in portable computing and wireless technologies are opening up exciting possibilities for the future of wireless mobile networking. A mobile ad hoc network consists of mobile platforms which are free to move arbitrarily. Since the nodes are mobile, internode connectivity may change frequently. There is an increasing demand for applications like multiplayer online gaming, where players residing at different locations participate in the same gaming session through their handheld portable devices. Such applications are characterized by a close degree of collaboration, typical of ad hoc network scenarios. Multicasting could prove to be an efficient way of providing necessary services for these kinds of applications; hence, it is imperative to determine what is the best way to provide these services in an ad hoc environment. Due to the very diverse requirements of the applications and the unpredictable nature of ad hoc networks, it is necessary to investigate and discern the applicability of existing ad hoc multicast protocols and quantify which is more suitable for which type of application. We provide a detailed description and comparison of ad hoc multicast protocols. We hope that this discussion is helpful to application developers in selecting an appropriate multicast protocol and paves the way for further research.

Multicast over wireless mobile ad hoc networks: present and future directions

In this paper we investigate the performance of multicast routing protocols in wireless mobile ad hoc networks. An ad hoc network is composed of mobile nodes without the presence of a wired support infrastructure. In this environment, routing/multicasting protocols are faced with the challenge of producing multihop routes under host mobility and bandwidth constraints. In recent years, a number of new multicast protocols of different styles have been proposed for ad hoc networks. However, systematic performance evaluations and comparative analysis of these protocols in a common realistic environment has not yet been performed. In this study, we simulate a set of representative wireless ad hoc multicast protocols and evaluate them in various network scenarios. The relative strengths, weaknesses, and applicability of each multicast protocol to diverse situations are studied and discussed.

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J. Hsu

Papers

A performance comparison study of ad hoc wireless multicast protocols