Analysis of Quality of Service in Wimax networks

Number of nodes
S
ec
ond
s
Figure 13 Average Delay with number of nodes for rtPS 
Figure 13 shows the variation of average delay for rtPS service flow. The average 
delay increases vary slightly as the number of nodes increases. For all practical purposes, 
there is number of nodes has very little impact on the average delay in case of VOIP 
traffic over rtPS service flow. 
4.1.3 Results for VOIP traffic over Unsolicited Grant Service Flow 
The following section presents the results for VOIP traffic using UGS service 
flow. The VOIP codec used here is G.711. The comparative results for all the codecs is 
presented in 4.1.5. 
Service Flow Type: Real Time Polling Service(rtPS) 
Traffic Type: VOIP 
VOIP Codec: G.711 ((64kbps): 80 bytes frame, 160 bytes payload, 50 pkts per sec.) 

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Throughput
0
100
200
300
400
500
600
0
2
4
6
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10
12
Number of nodes
kbps
 
Figure 14 Throughput with number of nodes for UGS 
Figure 14 shows the variation of throughput for VOIP traffic over UGS service 
flow. Again, as expected there is a steady increase as the number of nodes increases.
The values range from 116 kbps for 2 nodes to 560 kbps for 10 nodes. 
Service Flow Type: Unsolicited Grant Service(UGS) 
Traffic Type: VOIP 
VOIP Codec: G.711 ((64kbps): 80 bytes frame, 160 bytes payload, 50 pkts per sec.) 

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44
Packet Loss
0
0.0002
0.0004
0.0006
0.0008
0.001
0.0012
0.0014
0.0016
0
2
4
6
8
10
12