Wireless Ad Hoc and Sensor Networks

Distributed Power Control of Wireless Cellular and Peer-to-Peer Networks 2257 × 10−13 k v = 0016Channel change—Gii5432100 50Iterations100 150FIGURE 5.31Smoothed channel variation.probability with time wherein the outage probability using the proposedDPC scheme is significantly less (near zero) when compared to all theother schemes (about 85%), i.e., our approach can accommodate morenumber of mobile users rendering high channel utilization or capacity inthe presence of channel variations. This, in turn, implies that the powerconsumed per active user is less compared to other schemes.CASE II: SLOWLY VARYING CHANNEL In this scenario, . and σ = 3.In this case, though the channel changes every ten time-units, the channelvariation illustrated in Figure 5.31 follows the Rayleigh fading and shadowingbehavior. The channel variation is smoothed out using a linear functionbetween the changes. In this case also, the proposed DPC schemerenders a low outage probability (about 30% as observed in Figure 5.32)while consuming less power per active mobile because the proposed DPCscheme maintains the SIR of each link closer to its target compared to others.Other schemes result in about 85% outage probability. The low outageprobability for the proposed DPC scheme is the result of faster convergence,and low SIR error while it consumes satisfactory power per active user.Example 5.4.2: Performance Evaluation with Number of UsersWhen the total number of mobile users in the cellular network varies,we compare how the total power and outage probability vary. In this