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Routing protocols in mobile and wireless networks Mobile and wireless networks allow the users to access information and services electronically, regardless of their geographic location. There are infrastructured networks and infrastructureless (ad hoc) networks. Infrastructured network consists of a network with fixed and wired gateways. A mobile host communicates with a Base Station (BS) within its communication radius. The mobile unit can move geographically while it is communicating. When it goes out of range of one BS, it connects with a new BS and starts communicating through it by using a handoff | Mobile Telecommunications Protocols For Data Networks. Anna Hac Copyright 2003 John Wiley Sons Ltd. ISBN 0-470-85056-6 9 Routing protocols in mobile and wireless networks Mobile and wireless networks allow the users to access information and services electronically regardless of their geographic location. There are infrastructured networks and infrastructureless ad hoc networks. Infrastructured network consists of a network with fixed and wired gateways. A mobile host communicates with a Base Station BS within its communication radius. The mobile unit can move geographically while it is communicating. When it goes out of range of one BS it connects with a new BS and starts communicating through it by using a handoff. In this approach the BSs are fixed. In contrast to infrastructure-based networks in ad hoc networks all nodes are mobile and can be connected dynamically in an arbitrary manner. All nodes of these networks behave as routers and take part in discovery and maintenance of routes to other nodes in the network. Ad hoc networks are very useful in emergency search-and-rescue operations meetings or conventions in which persons wish to quickly share information and data acquisition operations in inhospitable terrain. An ad hoc network is a collection of mobile nodes forming a temporary network without the aid of any centralized administration or standard support services regularly available in conventional networks. We assume that the mobile hosts use wireless radio frequency transceivers as their network interface although many of the same principles will apply to infrared and wire-based networks. Some form of routing protocol is necessary in these ad hoc networks since two hosts wishing to exchange packets may not be able to communicate directly. Wireless network interfaces usually operate at significantly slower bit rates than their wire-based counterparts. Frequent flooding of packets throughout the network a mechanism many protocols require can consume .