- 學位論文
乙太被動式光纖網路之省電機制之設計
The Design of power saving mechanisms in Ethernet Passive Optical Networks
摘要
目前網際網路接取網路常建構被動式光學網路(PON)以符合日益增高的頻寬需求。然而提供越高的頻寬也意味著將損耗更多的能源。在近幾年來，為節省能源的消耗，有些研究探討了被動式光學網路架構之雙模式的節能設計，讓光纖網路終端機(ONU)適時的進入睡眠模式以達到節能的成效，因此，光纖網路終端機於系統運作中會在啟動模式與睡眠模式間切換。然而，這種雙模式的節能設計，在接取網路中若大多情況僅存在下行網路的流量，仍將造成不必要的能耗或封包時間延遲的增加。 本論文探討乙太被動式光學網路的節能機制設計，讓光纖網路終端機能在啟動、睡眠與淺眠三種模式中切換，期能設計兼顧節能與效能的解決方案，並滿足不同優先權封包之服務品質的需求。此機制透過淺眠模式的運作，維持網路下行通道的順暢；並利用提早喚醒機制來保障高優先權上傳資料的低時間延遲。透過模擬的效能評估結果顯示，本設計在各種不同上下傳網路負載量的情況下，均能滿足高優先權資料對於低時間延遲之服務品質的需求；而在具有大量下傳資料流量而僅有少量上傳資料流量的情況 (如一般的視訊串流應用服務) 下，本機制可展現比雙模式的節能設計更優異的節能成效。
並列摘要
Modern access networks are constructed widely by passive optical networks (PONs) to meet the growing bandwidth demand. However, higher bandwidth means more energy consumption. To save energy, a few research works propose the dual-mode energy saving mechanism that allows the ONU to switch into sleep modes whenever appropriately. Therefore, the ONU operates between active and sleep modes periodically. However, such dual-mode energy saving design may induce unnecessary power consumption or packet delay increase in the case that only downstream data exist for most of the time. In this thesis, we propose a new tri-mode energy saving scheme for Ethernet PON (EPON). The new tri-mode energy saving design, combined with the original dual-mode saving mechanism with the doze mode, allows the ONU to switch among these three modes alternatively. In the dose mode, the ONU may receive downstream data while keeping its transmitter close. Furthermore, the low packet delay of high priority upstream data can be attained through the use of early wake-up mechanism employed in both energy saving modes. The energy saving and system efficiency can thus be achieved jointly while maintaining the differentiated QoS for data with various priorities. Performance results via simulation reveal that such design can indeed meet the low packet delay requirements of high priority data under various loading. In addition, superior energy saving results can be observed whenever only lots of downstream data exist in the network, such as video streaming download services.