SBF-GWF scheduling for Combined Input-Crosspoint-Queued (CICQ) switches

Combined Input-Crosspoint-Queued (CICQ) crossbar switches are advantageous in performance over input-queued (IQ) switches. As a result, many scheduling schemes have been developed for CICQ switches to further improve their performance. This paper presents a new scheduling scheme called SBF-GWF (the Shortest buffer First and the Greatest Weigh buffer First). It takes the advantage of the SBF algorithm used in MCBF input arbiters with an additional feature that uses VOQ lengths as weights, which will in turn be used for privileged output with the fluid model, we have proved that SBF-GWF algorithm can achieve 100% throughput for any admissible traffic without the need of speed-up for crossbars. Our simulation results have also shown that SBF-GWF algorithm exhibits good delay performance under any admissible traffic compared with existing scheduling schemes.