Abstract: A communication unit (110) that wants to transmit a data packet to another communication unit (105) must acquire access to a common communication channel (not shown) before transmitting a data packet (440). For data packets of realtime applications, quality of service (QOS) parameters for the data packet are used to define transmission parameters to communicate the data packet (440). These parameters include Taccess (420) and Tdelay (430). In addition, compliance with predetermined requirements of size relationship between request-to-send (RTS) and clear-to-send (CTS) packets are imposed.

Abstract: The present distributed scheduling architecture comprise a hierarchy of schedulers comprising one master scheduler and many slave schedulers. The master scheduler is located at the AP. Its basic role is to allocate physical bandwidth to the different terminals. The slave scheduler is located in the data link control layer of a wireless terminal and one is located in the AP. It is important to note that at the AP, both master scheduler and slave scheduler (AP) co-exist while at the wireless terminals only slave schedulers (WT) are implemented. The rationale behind this architecture, is that the AP allocates time slots to the wireless terminals based on the information it receives through the reservation protocol, however, to cope with the problem of this information being out of date, the wireless terminals are allowed to freely distribute the allocated slots among their connections.

Abstract: A packet scheduling system is disclosed in which a plurality of first-in-first-out input buffers are provided each corresponding to a respective input data stream to a switching node or multiplexer. Credit is allocated to each stream having packets waiting to be transmitted and which is unable to transmit, and the next stream to be transmitted is based on the allocated credit values, the credit of a transmitted stream being reduced after transmission of a data packet from that stream.