乙太被動式光纖網路中具流量感知性質之節能機制設計

簡嘉志 ； 劉健平 ； 吳和庭 ； 柯開維

《TANET2016 臺灣網際網路研討會》 2016 (2016/11) Pp. 1140-1145-203

https://doi.org/10.6679/TANET.2016.203

摘要

本論文提出一項具流量感知的節能機制設計，來減少乙太被動式光纖網路(EPON)系統非必要能源損耗。在本設計中，在節能模式的ONU無法傳送前週期殘留或本週期剛抵達的封包。為了掌握ONU節能狀態下的剩餘負載，本機制須分別量測上下行通道剩餘負載。針對下行剩餘負載量測，每次OLT發送GATE訊息前，量測下行流量；而上行流量量測，則是利用每次ONU發送REPORT訊息前量測上行流量。藉由比較量測到的數值與定義的門檻值，本機制將流量區分為高低流量負載。本機制只允許ONU在高流量負載狀態才可以傳輸，若是低流量負載則ONU進入節能模式。在低流量負載時將封包儲存在佇列中，可以讓ONU在節能模式下停留更久時間，達到節能的目標。此外，本機制為避免過長的高優先權封包傳輸延遲，只要當佇列中有高優先權封包，就不會將ONU轉換成節能模式以兼顧網路效能。透過模擬結果顯示，相較於先前三模式節能機制，本機制能在不影響高優先權封包時間延遲的情況下，可以有效減少能源損耗。

關鍵字

乙太被動式光纖網路 ； 節能模式 ； 淺眠模式 ； 睡眠模式 ； 流量感知 ； 剩餘負載

並列摘要

This study proposes a loading aware power saving mechanism for EPON system to reduce unnecessary energy consumption. The ONU in power saving mode cannot transmit those packets which are residue after previous cycle or just arrives in current cycle. To identify the incoming traffic loading in the power saving mode, the proposed mechanism measures a remaining loading for upstream and downstream channel respectively. For measuring downstream remaining loading, OLT measures the loading every time before sending GATE message. As to measure upstream remaining loading, ONU measures the loading every time before sending REPORT message. By comparing a predefined threshold with the measured remaining loading, the proposed mechanism classifies current traffic loading to the heavy or light level. The proposed mechanism only allows ONU to transmit packets in heavy loading, otherwise ONU changes to power saving mode in light loading. The proposed mechanism accumulates packets in light loading to allow ONU to stay in power saving mode for a longer time. Besides, in order to avoid long transmission delay of high priority packets, the ONU will not switch to power saving mode if the queue of high priority packets is not empty. The simulated results reveal that the proposed mechanism can reduce energy consumption without affecting the high priority packet delay, compared with those results achieved by the previous tri-mode power saving mechanism.

並列關鍵字

EPON ； Power saving mode ； Doze mode ； Sleep mode ； Loading aware ； Remaining loading