| 摘要 |
PURPOSE: A method for scheduling cells according to weighted priority of an ATM(Asynchronous Transfer Mode) switch is provided to compare predetermined weight values, assigned for each queue included in a schedule queue with corresponding weight coefficients, so as to prevent schedule information stored in a queue relatively having a lower priority from not being outputted for a long time. CONSTITUTION: A weighted priority analysis block(44) of a scheduler(40) receives predetermined weight values for each queues(52-55) except for a CBR(Constant Bit Rate) queue(51) having a highest priority. The weighted priority analysis block(44) confirms whether queues(52-55) having weight coefficients larger than the weight values exist. If exist, the weighted priority analysis block(44) delivers schedule information stored in the corresponding queues(52-55) to a transmission control unit, and initializes weight coefficients for corresponding queues(52-55) to 0(zero). The weighted priority analysis block(44) confirms whether queues(51-55), except for presently selection-controlled queues, storing schedule information exist. If exist, the weighted priority analysis block(44) increases weight coefficients for corresponding queues(51-55) by 1(one), and the step of confirming queues(52-55) having weight coefficients larger than the weight values is returned. If queues(51-55) storing schedule information do not exist, the step of confirming queues(52-55) having weight coefficients larger than the weight values is returned. If queues(52-55) weight coefficients larger than the weight values do not exist, the weighted priority analysis block(44) sequentially confirms whether queues(51-55) storing schedule information exist, according to absolute priority. If exist, the weighted priority analysis block(44) delivers schedule information stored in the corresponding queues(51-55) to the transmission control unit, and initializes weight coefficients for corresponding queues(51-55) to 0(zero). Then, the step of confirming whether queues(51-55), except for presently selection-controlled queues, storing schedule information exist is returned.
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