**3.2 Simulation**

Simulations were carried out to observe the improvement in throughput by implementing user based packet classification. Priority 3 scenario of table 11 was simulated. The simulation network consists of one priority MS whose packets are prioritized as per Priority


3. Other MS are regular users whose packets are prioritized as per priority 1. Table 11 lists the simulation parameters used.

Table 11. Simulation Parameters.

Figure 12 shows the simulation results for BE traffic when the priority MS and regular MS generate both RTPS and BE packets. For priority MS, the BE packets are classified as RTPS packets.

Fig. 12. BE data (in Kbps) transmitted by priority-SS compared to regular-SS.

From Fig. 12 we see that, when the number of MS in the network are less than 8, both Priority MS and non-priority MS are able to transmit all their data. When the number of MS in the network goes beyond 8, there isn't enough bandwidth to support the BE traffic for non-priority users. So the average throughput for non-priority user drops. Since priority MS

3. Other MS are regular users whose packets are prioritized as per priority 1. Table 11 lists

Arrival Pattern for RTPS Traffic Variable bit rate packets at regular

Figure 12 shows the simulation results for BE traffic when the priority MS and regular MS generate both RTPS and BE packets. For priority MS, the BE packets are classified as RTPS

interval of time

Uplink Bandwidth 2Mbps

Number of Uplink frames per second 1000/Sec Maximum Uplink bandwidth per SS per Frame 400 bits/frame Minimum Reserved Traffic Rate for RTPS 240Kbps

Uplink Frame Duration 1msec (2000 bits)

Arrival Pattern for BE Traffic Poisson Arrival Average arrival Rate for RTPS traffic 160Kbps Average arrival Rate for BE traffic 72Kbps

Fig. 12. BE data (in Kbps) transmitted by priority-SS compared to regular-SS.

From Fig. 12 we see that, when the number of MS in the network are less than 8, both Priority MS and non-priority MS are able to transmit all their data. When the number of MS in the network goes beyond 8, there isn't enough bandwidth to support the BE traffic for non-priority users. So the average throughput for non-priority user drops. Since priority MS

**Parameter Value** 

the simulation parameters used.

Table 11. Simulation Parameters.

packets.

request bandwidth for their BE traffic as RTPS traffic, priority MS continue to receive bandwidth. Beyond 12 SS there isn't enough bandwidth to support elevation of BE traffic as RTPS traffic. So throughput for even priority-MS drops down. Fig. 13 shows the simulation results when the network consists of only BE traffic.

Fig. 13. BE data transmitted by priority-MS and regular-MS when only BE packets are present in the network.

In Fig. 13 we see that priority MS enjoy constant throughput of 70Kbps where as the throughput for non-priority MS keeps decreasing as the number of MS increases. This happens because BE traffic for priority MS is treated as RTPS traffic. So bandwidth is allotted to priority MS. The leftover bandwidth is shared by non-priority MS. So, by implementing priority based packet classification we can provide graded QoS to the users.
