Wireless Ad Hoc and Sensor Networks

1Background on NetworkingComputer or communication networks can be broadly classified based onwhether they are physically connected or are intermittently connectedusing radio signals. Computer networks that are connected by a piece ofwiring, such as a coaxial cable are known as wired networks. Wirelessnetworks use radio signals as their physical layer. The ability to connecttwo or more computers without the need of cumbersome wiring and theflexibility to adapt to mobile environments have been fueling the widespreadacceptance and popularity of wireless networks. For an overviewof computer networks refer to (Stallings 2002, Chao and Guo 2002, Walrandand Varaiya 1996, Tanenbaum 1996).1.1 Computer NetworksCommon examples of wired networks are the Internet and asynchronoustransfer mode (ATM) networks. The broadband integrated services digitalnetwork (B-ISDN) with standardized ATM is envisaged to support newservices with varying traffic characteristics and quality of service (QoS)requirements that are imposed by the users. In simple terms, ATM is aconnection-oriented packet switching and multiplexing technique thatuses short fixed-size cells to transfer information over a B-ISDN network.The short cell size of ATM at high transmission rates is expected to offerfull bandwidth flexibility and provide the basic framework for guaranteeingQoS requirements of applications with a wide range of performancemetrics, such as delay and loss.Meanwhile, the advent of broadband networking technology has dramaticallyincreased the capacity of packet-switched networks, from a fewmegabits per second to hundreds or even thousands of megabits persecond. This increased data communication capacity allows new applicationssuch as videoconferencing and Internet telephony. These applicationshave diverse QoS requirements. Some require stringent end-to-enddelay bounds; some require a minimal transmission rate whereas others1