MANET

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A "Mobile Ad Hoc Network" (MANET) is an autonomous system of mobile routers connected by wireless links--the union of which form an arbitrary graph. The routers are free to move randomly and organize themselves arbitrarily; thus, the network's wireless topology may change rapidly and unpredictably.

It is a collection of mobile nodes which communicate over radio and do not need any pre installed communication infrastructure. Communication can be performed if two nodes are close enough to exchange packets. The nodes in a MANET can dynamically join and disjoin the network, frequently, often without warning, and possibly without disruption to other nodes’ communication. Finally, the nodes in the network can be highly mobile, thus rapidly changing the node constellation and the presence or absence of links Wireless ad hoc networks (also referred to as packet radio networks and multi-hop radio networks) consist of mobile nodes communicating over a shared wireless channel. Contrary to cellular networks, where the nodes are restricted to communicate with a set of carefully placed base stations, there are no base stations in wireless ad hoc networks and two nodes either communicate directly using Single Hop or indirectly using Multi-Hop routing to deliver their packets to distant destinations. The lack of wired infrastructure, the nature of the wireless channel, and the mobility of the nodes create many challenging problems in the link, network, and higher levels of the OSI hierarchy. On the other hand, the lack of wired infrastructure and their topology make these networks ideal for many applications, from personal area networks, search and rescue operations. It is therefore expected that, once all the technological issues are solved, wireless ad hoc networks will become an integral part of our society's telecommunication infrastructure. MANET is an autonomous system of mobile nodes. The nodes may consist of separate, networked devices, or may be integrated into a single device such as a laptop computer. The nodes may be located in or on any type of moving vehicles like airplanes, ships, trucks, cars, perhaps even on people, and there may be multiple hosts per router. The nodes are equipped with wireless transmitters and receivers using antennas which may be omni-directional (broadcast), highly-directional (point-to-point) or some combination thereof. At a given point of time, depending on the nodes’ positions and their transmitter and receiver coverage patterns, transmission power levels and co-channel interference levels, a wireless connectivity in the form of a random, multi-hop graph or “ad hoc” network exists between the nodes. This is in contrast with the topology of the existing Internet, where the router topology is essentially static (barring network reconfiguration or router failures). Even the wireless sensor network is an emerging application area for ad hoc networks which has been receiving a large attention.