Simple scheduling algorithm for delay guarantee in VOQ architecture switches

Combining the earliest deadline first (EDF) policy and round robin manner, a simple scheduling algorithm was proposed to provide flow-based deterministic delay guarantee in virtual output queueing (VOQ) architecture switches. The EDF policy was employed to arbitrate the flow competitions in VOQ queues, and the round robin strategy was used to build input and output matching. In this case, the interval time between a packet arrival and that when it becomes the head cell in the VOQ, and the time from the packet becomes the head cell to it has been conveyed to the correspond output can be regard as the queuing time and service time in OQ architecture, respectively. The relation between the delay bounds and the packet inter-arrival times were derived. More important, the obtained results not only pave the way for design of more efficient algorithms, but also provide a novel approach to estimating that if there exist conflicts among the distinct delay bounds or not.