Samuel Kakuba, Kyanda Swaib Kaawaase and Michael Okopa
In a recent study, an Enhanced Low Latency Queue (ELLQ) scheduling algorithm that categorizes and prioritizes the real-time traffic was developed. In this algorithm the high priority queues are introduced for scheduling the video applications separately along with the voice applications, with voice applications having a higher priority over video applications. The low priority queues are serviced using CBWFQ. However, at high arrival rate of voice packets, the video packets may suffer resource starvation. To overcome this drawback, we propose an improved LLQ algorithm which delays voice packets that arrive while the video packets are already in the queue and services video packets found in the queue before servicing voice packets as long as the voice packets are not delayed beyond the maximum tolerable delay limit. The numerical results obtained from the derived models show that average waiting time of both voice and video packets increase with increase in load and arrival rates of packets in the system. We also observe that delaying voice packets leads to reduction in the average waiting time of video packets and an increase in the average waiting time of voice packets, however the reduction in average waiting time of video packets is higher than the increase in the average waiting time of voice packets. The reduction in average waiting time of video packets and increase in average waiting time of voice packets are higher for high loads and high arrival rates. Furthermore, we observe that voice packets can be delayed to serve video packets as long as the load and arrival rates of voice packets does not exceed 81% and 14 packets/second respectively and less dependent on the load and arrival rates of video packets.
