I. Introduction
Mobile ad hoc networks (MANETs) have attracted many research efforts over the past few years. A mobile ad hoc network is composed of several wireless mobile devices that are capable of communicating with each other in a peer-to-peer basis. The distinct feature of such a network is lack of fixed infrastructure and centralized administrative in the network. Each node acts not only as a host but also as a router, forwarding packets on behave of other nodes that are out of the direct radio range of their destinations. The self-organized and self-configured nature of MANETs provides a flexible alternative in a variety of applications where the deployment of a fixed infrastructure may be impractical. Consequently, MANETs are useful in military and other tactical applications such as emergency rescue or exploration missions. Furthermore, commercial situations (i.e. conferences, course training, lectures, museum visits, city tours, e-gaming and peer-to-peer applications) are potential application fields for the requirement of ubiquitous communication.