BANDWIDTH ALLOCATION, TRANSMISSION SCHEDULING, AND CONGESTION AVOIDANCE IN BROADBAND ATM NETWORKS

摘要

A wide variety of call traffic is effectively integrated in a singlebroadband communications network. Calls having widely differing bandwidthrequirements and sensitivities to delay are handled by the network with efficient,effective, and fair bandwidth allocation and transmission scheduling. This isaccomplished by classifying each call in accordance with certain signal characteristics,such as required bandwidth and sensitivity to delay. Each call class is directed to aseparate queuing circuit. Some calls in certain classes, such as those associated withhigh-bandwidth constant bit rate services, are each directed to their own individualqueuing circuits. Other calls within a class are statistically multiplexed into a singlequeuing circuit for that class. A multiplexing circuit operates in accordance with adynamic time slice scheme which involves defining a service cycle time period duringwhich the multiplexer withdraws a predetermined number of information packets fromeach of a plurality of queuing circuits containing information packets and places thosepredetermined numbers of packets onto an output link. The multiplexer breaks up thecycle time period into a plurality of time slices, each of which determines how manyinformation packets are transmitted from each queuing circuit during the cycle timeperiod. Efficient resource usage and congestion avoidance are further achieved byusing one of a number of alternative scheduling techniques for delay insensitivetraffic.