An Improved Node Scheduling Scheme for Resilient Packet Ring Network

Priority Queue (PQ) algorithm is used as the scheduling scheme for Resilient Packet Ring network (RPR). The scheduler handles a specific queue on the basis that all the higher priority queues have been served and emptied. This approach ensures low delay for higher priority classes of traffic. However, it often leads to the starvation of lower priority queues. For both single transit and double transit buffer architecture, traffic on the ring, which is a mixture of HP and LP transit traffic, has higher priority over the transmit HP traffic. This could cause the LP traffic on the ring to block the transmit HP traffic from gaining access onto the ring. To improve the quality of service for high priority traffic transmission, we propose using Bitwise Round-Robin (BRR) algorithm to alternately select packets from the transit buffer and the high priority transmit buffer. Simulation results show certain improvement on overall delay and delay jitter performance of RPR networks by using our scheme.