Wireless Ad Hoc and Sensor Networks

108 Wireless Ad Hoc and Sensor NetworksS2S3D3D2S1D1Link 0 Link 1 Link 2Router 1 Router 2 Router 3 Router 4Link 3S4D4S5 S6 D6 D5FIGURE 3.19Extended topology with multiple bottlenecks.From Figure 3.11, we can once again see the CLR obtained using theproposed congestion control scheme is much better than the thresholdbasedcongestion control scheme. In fact, the CLR using the congestioncontrol scheme is equal to zero and, as in Example 3.4, the controllerreduces the source rates fairly. The results between proposed and threshold-basedcontrol are shown in Table 3.3.3.4 End-to-End Congestion Controller Designfor the InternetIn recent years, the emergence of high-speed Internet and increase inmultimedia traffic has spawned several challenging problems for thesmooth transfer of data. As the Internet offers best-effort service to multimediatraffic and, because, this traffic has bursty traffic characteristicsand various QoS and bandwidth requirements, a high-speed Internetrequires a real-time control scheme that manages the admission and controlof traffic flows to avoid congestion.Congestion and admission control protocols are too numerous to mention;only the important ones are referred to here. Several schemesTABLE 3.3Comparison of Results for the Extended Topology3VBR+3CBR NN Threshold-BasedTotal cell loss 0 73Cell loss ratio 0 0.42%Normalized delay 0.6587 0.6643System power 6.9984 6.968