Ad hoc wireless distribution service

About: Ad hoc wireless distribution service is a research topic. Over the lifetime, 17734 publications have been published within this topic receiving 488205 citations.

Wireless ad hoc networks

Abstract: A mobile ad hoc network is a relatively new term for an old technology - a network that does not rely on pre-existing infrastructure. Roots of this technology could be traced back to the early 1970s with the DARPA PRNet and the SURAN projects. The new twitch is the application of this technology in the non-military communication environments. Additionally, the research community has also recently addressed some extended features of this technology, such as multicasting and security. Also numerous new solutions to the “old” problems of routing and medium access control have been proposed. This survey attempts to summarize the state-of-the-art of the ad hoc networking technology in four areas: routing, medium access control, multicasting, and security. Where possible, comparison between the proposed protocols is also discussed. Keywords: ad hoc networks; MANET; MAC protocols for ad hoc network; routing protocols for ad hoc networks; proactive routing protocols; reactive routing protocols; hybrid routing protocols; multicasting for ad hoc networks; security for ad hoc networks

A simulation study of table-driven and on-demand routing protocols for mobile ad hoc networks

Abstract: Bandwidth and power constraints are the main concerns in current wireless networks because multihop ad hoc mobile wireless networks rely on each node in the network to act as a router and packet forwarder. This dependency places bandwidth, power, and computation demands on mobile hosts which must be taken into account when choosing the best routing protocol. In previous years, protocols that build routes based on demand have been proposed. The major goal of on-demand routing protocols is to minimize control traffic overhead. We perform a simulation and performance study on some routing protocols for ad hoc networks. The distributed Bellman-Ford (1957, 1962), a traditional table-driven routing algorithm, is simulated to evaluate its performance in multihop wireless network. In addition, two on-demand routing protocols (dynamic source routing and associativity-based routing) with distinctive route selection algorithms are simulated in a common environment to quantitatively measure and contrast their performance. The final selection of an appropriate protocol will depend on a variety of factors, which are discussed in this article.

Preemptive routing in ad hoc networks

Abstract: Routing in ad hoc networks is a challenging problem because nodes are mobile and links are continuously being created and broken. Existing on-demand ad hoc routing algorithms initiate route discovery only after a path breaks, incurring a significant cost in detecting the disconnection and establishing a new route. In this work, we investigate adding proactive route selection and maintenance to on-demand ad hoc routing algorithms. More specifically, when a path is likely to be broken, a warning is sent to the source indicating the likelihood of a disconnection. The source can then initiate path discovery early, potentially avoiding the disconnection altogether. A path is considered likely to break when the received packet power becomes close to the minimum detectable power (other approaches are possible). Care must be taken to avoid initiating false route warnings due to fluctuations in received power caused by fading, multipath effects and similar random transient phenomena. Experiments demonstrate that adding proactive route selection and maintenance to DSR and AODV (on-demand ad hoc routing protocols) significantly reduces the number of broken paths, with a small increase in protocol overhead. Packet latency and jitter go down in most cases. Because preemptive routing reduces the number of broken paths, it also has a secondary effect on TCP performance--unnecessary congestion handling measures are avoided. This is observed for TCP traffic under different traffic patterns (telnet, ftp and http). Additionally, we outline some problems in TCP performance in ad hoc environments.

Security in Ad Hoc Networks: a General Intrusion Detection Architecture Enhancing Trust Based Approaches.

Abstract: In the last few years, the performances of wireless technologies have increased tremendously thus opening new fields of application in the domain of networking. One of such fields concerns mobile ad hoc networks (MANETs) in which mobile nodes organise themselves in a network without the help of any predefined infrastructure. Securing MANETs is just as important, if not more, as securing traditional wired networks. Existing solutions can be used to obtain a certain level of security. Nevertheless, these solutions may not always be suitable to wireless networks. Furthermore, ad hoc networks have their own vulnerabilities that cannot be tackled by these solutions. To obtain an acceptable level of security in such a context, traditional security solutions should be coupled with an intrusion detection mechanism. In this paper we show how ad hoc networks can be, to a certain extent, secured using traditional techniques. We then examine the different intrusion detection techniques and point out the reasons why they usually cannot be used in an ad hoc context. Finally, we go through the requirements of an intrusion detection system for ad hoc networks, and define an adapted architecture for an intrusion detection system for manets.