A dynamic priority scheme for broadband switching

A dynamic priority scheme for a broadband communication switching architecture that combines the flexibility of statistical multiplexing with the fixed size packet slots found in time-division multiplexing is proposed. The technique presented recognizes two major classes of customers with two levels of priority: higher-level priority for isochronous traffic and lower-level priority for nonisochronous traffic. At any point in time, packets belonging to the isochronous class are served in favor of their nonisochronous counterparts. Nonisochronous packets are served only when there are no isochronous packets ready for transmission. A subpriority counting scheme is exercised in the isochronous class to allocate the transmission facility effectively and equitably and hence minimize the variation of time delay not tolerable by most real-time applications. Under this transmission strategy, packet switching can be satisfactorily accommodated with or without adopting a slight modification to the switch. In addition, the proposed technique has a potentially high bandwidth utilization factor, the flexibility to adapt to different communication environments, and the inherent structural simplicity of the fixed-size packet approach