Wireless Ad Hoc and Sensor Networks

Background on Networking 35mathematically, and the performance requirements, like low-outageprobability and high spatial reuse, an important requirement in wirelessnetworks, are not satisfied. A system theory approach for solving a networkingproblem has been taken advantage of in the proposed scheme.When new users try to access the channel, active users may be inadvertentlydropped because of fluctuation in maintaining the QoS metrics.An active user may be dropped even if there is a possibility of new userseventually getting accommodated at the steady state. Moreover, theadmission of new users on to the wireless network is essential to maintainhigh system utilization and to ensure certain QoS metrics like low endto-enddelay and low packet losses in the network. An efficient powercontrol scheme, given in Chapter 5 in this book, provides protection forlinks that are currently operational, by maintaining the QoS of the usersat all times even as new users try to enter the network.Constant topology changes, due to mobile users in the wireless network,require that the active wireless links are protected during a session inprogress. Very few DPC schemes proposed in the past have consideredaddressing this issue. Link between the users in the network should beprotected by satisfying minimum QoS requirements for example, mechanismsto maintain a minimum SNR when a call is initiated and is in progress.The proposed power control scheme is aimed at providing active link protectionfor the users in the network by satisfying the QoS requirements.Modifications are needed for the existing protocols to accommodate theproposed power control schemes. Existing standards and protocols inplace for ad hoc wireless networks do not allow users to transmit atdifferent power levels. So, changes to the packet formats in control messages,and minor changes in the functionality in physical and MAC layers,will enable the implementation of the proposed DPC schemes with activelink protection. Next, we present an overview of WSNs.1.5 Wireless Sensor NetworksSmart environments represent the next evolutionary step in building,utilities, industrial, home, shipboard, and transportation system automation.Like any organism, the smart environment relies on real world sensorydata, which comes from multiple sensors of different modalities in distributedlocations. The smart environment needs information about itssurroundings as well as about its internal workings.Sensor networks are the key to gathering the information needed bysmart environments, whether in buildings, utilities, industrial, home, shipboard,transportation systems, automation, or elsewhere. Recent terrorist