ATM SERVICE SCHEDULER USING REVERSE-BINARY SCATTERING AND TIME-SPACE MAPPING

A method for scheduling low delay-jitter cell transmissions for multiple streams of Asynchronous Transfer Mode (ATM) traffic from a node is disclosed. Cells belonging to multiple streams of virtual circuits (VCs) and virtual paths (VPs) are stored in the node's memory. A link controller scans a time-space map to determine when a given stream will be sampled and its cells transmitted from the memory out over a link. The time-space map is comprised of time-slots whose spatial positions within the map correspond to times at which cells can be transmitted. A scattering technique, based on reverse-binary or other mapping schemes, ensures that each given stream occupies time-slots that are well-spaced within the time-space map. This ensures that cells belonging to a given stream are transmitted at well-spaced intervals of time. The scheduler can provide each stream with a guaranteed real number of time-slots per time-space map, which allows for high resolution service rates to be supported without having to resort to using very large maps. 58