An Insertion Mode Scheduler for improving QoS of real-time services

Traditional packet scheduling algorithms such as PQ (Priority Queuing) and WFQ etc. are packet-by-packet schedulers, in which a packet of a real-time service has to wait before a long non-real-time packet finishes transmitting if the real-time packet arrives after the beginning of the non-realtime packet's transmitting. This will have a bad effect on the delay and delay variation of the real-time service. An Insertion Mode Scheduler(IMS) is proposed in the paper, which allows a real-time packet to insert into a non-real-time packet when the latter is transmitting. The method of implementing the IMS is described and the simulation results are given, which show that the QoS performance is improved compared with the traditional packet-by-packet schedulers.