Analysis of Quality of Service in Wimax networks

 
Figure 37 Average Delay with number of nodes for UGS service flows 
Figure 37 displays the variation of average delay as the number of nodes with 
UGS traffic increases. Again, similar to average jitter, the variation in delay as the 
number of nodes increases is very small.
4.2.4 Comparative Results for video traffic
When the three service flows are compared on a single graph some interesting 
patterns can be observed. Figure 38 shows the variation of overall throughput for video 
traffic as the number of nodes increase. The overall throughput is marginally higher in 
case of UGS service flow. For 10 nodes, the rtPS throughput is the lowest. This can be 
explained in conjunction with Figure 39 which displays the packet loss. 
Service Flow Type: Unsolicited Grant Service (UGS) 
Traffic Type: Video 
Video Parameters:64kbps H.263 

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Throughput
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Figure 38 Variation of Throughput for all service flows for video traffic 
Figure 39 shows the variation of packet loss with number of nodes. The rtPS 
service flow has very high rate of packet loss as the number nodes increase. This is 
because of the bandwidth request mechanism used in rtPS service flows. There is a lot of 
overhead in requesting bandwidth from the base station. 
Service Flow Type: Combined 
Traffic Type: Video 
Video Parameters:64kbps H.263 

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