INTER-CLASS SCHEDULERS UTILIZING PRIORITY GUARANTEED QUEUING

摘要

Inter-class schedulers for digital link systems provide high efficiency utilization of limited bandwidth by employing queuing techniques referred to as Statistical Priority Guarantee Queuing (SPGQ) and Generic Cell-Rate Algorithm Priority Guarantee Queuing (GCRA-PGQ). SPGQ "elevates" the priority of otherwise low-priority classes under prescribed circumstances in accordance with a statistical process. The SPGQ scheduler determines whether a number within a range produced by a uniform random number generator lies within a sub-range proportional to the programmed statistical guarantee for a given class. If the number lies within the sub-range associated with a given class, then the priority of that class is elevated to a higher priority when both are eligible to transmit. The GCRA-PGQ scheduler operates as a strict priority mechanism until a class requires bandwidth in excess of a GCRA "window" or threshold for that class. When that occurs, the service priority of that class is temporarily lowered.