近年來行動通訊技術的發展日新月異，IEEE 802.16e無線都會型網路(WMAN)是一種支援行動網路以及戶外移動基地台(MS)的最新科技。因為MS是利用電池供電，因此它支援了省電模式以節省電力使用並且能夠提供所需要的服務品質。規格中定義了三種不同的省電模式，¬而每一種模式並擁有自己的省電參數。 在設定正確的參數之下，每一種省電模式將正常運作以延長電池的壽命。然而，如果連往MS的連線數量增加，省電的行為將不會單單是依照著省電參數而運作。因為MS只有在所有的連線在同一個時間框架都進入省電模式時，才會真的進入省電模式。除此之外，只要有任何一個連線還停留在正常模式，就算其他連線希望MS進入省電模式，MS還是無法進入省電模式以達到省電的目的。 因此，多重連線的情況將會降低MS整體的省電效率。在這篇論文當中，我們提出了一種新的智慧策略讓BS能夠用來設定在多重連線狀況下，IEEE 802.16e MS的省電參數。我們會先解釋IEEE 802.16e睡眠模式，接下來會提出智慧策略，而這個策略會用來指定每個連線的省電參數以延長電池的使用壽命。最後利用模擬發現，本智慧策略的勝過規格當中所定義的方式。 Recently, mobile communication technologies have been developed rapidly. The IEEE 802.16e wireless metropolitan area network (WMAN) standard is an emerging technology to support roaming mobility of mobile stations (MSs) in outdoor environment. For MSs powered by batteries, the standard supports power saving mode to conserve battery power meanwhile fulfilling the requirements of quality of services. Regarding to different service types, standard defines three different power saving types for them and each type has its own power saving parameters. By setting appropriate parameters, single type of power saving will work well for extending the battery life. However, if the number of established connections of MS is more than one and the number of associated power saving type is more than one, the sleeping behavior is not following the setting parameters because that the MS will enter sleep mode only when all of connections decide to enter sleep at a same time. In other words, for a time frame, if there is any one connection is in listening mode, the MS shall not turn down the wireless transceiver. Therefore, such multi-connection case may degrade power saving efficiency. In this dissertation, we propose a smart strategy for base station (BS) to configure the parameters of power saving classes for MSs with multiple connections. At first, we explain and discuss the features of IEEE 802.16e sleep modes and then propose a smart strategy for merging parameters of different power saving classes in order to extend the battery life. Performance of proposed strategy is evaluated by simulations and simulation results illustrate that the proposed strategy with single parameter set outperforms the standard strategy with multiple parameter sets.
