| Summary: | 碩士 === 國立成功大學 === 資訊工程學系 === 102 === Time-division-multiplexing passive optical network (PON) has been considered in the past few years as a cost-effective broadband access technology. With the ever-increasing power saving concern, energy efficiency has been an important problem in PONs’ operations. To save energy in PONs, one of the methods is to allow the optical network unit (ONU) to go into sleep mode. In this mode, ONU can’t transmit and receive frames, so the frame delay may increase. Therefore, there is a tradeoff between frame delay and power consumption. It’s hard to give consideration to both frame delay and power consumption. The authors of Green bandwidth allocation (GBA) proposed a framework which uses the batch-mode transmission feature to minimize the frequency of ONU in on-off transitions. The optimal sleep time of each ONU is determined in every cycle without violating the maximum delay constraint.
However, if each ONU has different maximum delay constraint, using the maximum delay constraint to decide the sleep time may cause some packets of ONU to violate theirs delay constraint. Accordingly, we proposed a framework called “Group By Remaining Sleep time” that inspects the remaining sleep time and groups ONUs by the sleep length every cycle to avoid violating each ONU’s frame delay constraint. Finally, we set up ONUs with different delay constraint to evaluate the performance of GBRS. The simulation result shows that the grouping method of GBRS keep ONUs not impair their delay constraint in different test cases.
|
|---|
