Wireless Ad Hoc and Sensor Networks

230 Wireless Ad Hoc and Sensor Networks5.5 ConclusionsIn this chapter, a suite of DPC/ALP schemes is presented capturing theessential dynamics of power control. It was observed that the proposedDPC/ALP schemes allow fully distributed power and admission control,supporting ALP. The key idea introduced and leveraged here is to use aprotection margin (matched with gradual power-up) in the dynamics ofthe SIR. Using a novel power update, it is shown that the overall systemmaintains a desired target SIR value for each link analytically. The analyticalresults are verified via simulation in several scenarios where the link arrivalsare simulated in a uniform distribution. Simulation results show that ourDPC/ALP schemes offer a superior performance in terms of convergenceand maximizing the network capacity compared to the available ones inthe literature both for peer-to-peer and cellular network scenario.Subsequently, the DPC scheme is modified to render satisfactory performancein the presence of radio channel uncertainties. The simulationresults show that the modified DPC scheme converges faster than others,maintains a desired target SIR value for each link and can adapt to thechannel variations in the radio channel better. In the presence of channeluncertainties, the DPC scheme can render lower outage, using significantlyless transmitter power per active user compared to other DPC schemes.As a result, the DPC schemes of Chapter 5 offer superior performance interms of convergence, and it maximizes the network capacity comparedto the available ones in the literature. In the next chapter, the applicabilityof these schemes will be exploited for wireless ad hoc networks.ReferencesAein, J.M., Power Balancing in Systems Employing Frequency Reuse, COMSATTechnical Review, 1973, pp. 277–299.Alavi, H. and Nettleton, R.W., Downstream power control for a spread spectrumcellular mobile radio system, in Proceedings of IEEE GLOBECOMM, 1982,pp. 84–88.Bambos, N., Chen, S.C., and Pottie, G.J., Channel access algorithms with activelink protection for wireless communication networks with power control,IEEE/ACM Transactions on Networking, Vol. 8, 583–597, October 2000.Bambos, N., Toward power-sensitive network architectures in wireless communications:concepts, issues and design aspects, IEEE Personal Communications,Vol. 5, June 1998, pp. 50–59.Canchi, R. and Akaiwa, Y., Performance of adaptive transmit power control in p/4DQPSK mobile radio systems in flat Rayleigh fading channels, Proceedingsof the IEEE Vehicular Technology Conference, Vol. 2, 1999, pp. 1261–1265.