IEEE 802.16e在MAC層定義了MS的省電模式稱為睡眠模式(Sleep Mode)，以節省MS的電源消耗及減少佔用Serving BS的air interface資源。在睡眠模式下由於MS的行為受到了限制，MS的運作與其在正常運作模式(Normal operation or No sleep)下的運作有很大的差異，若要將正常運作模式下的鄰近基地台掃描機制直接運用於睡眠模式，則將大大降低MS省電的效能。
為了兼顧MS的行動性及省電的效能，本文從三方向著手，(1)使MS在適當的時機進行掃描(When to scan) ，(2)使MS有適用的機制可以進行掃描(How to scan) ，(3)減少掃描的次數，提出改良式應用簡單線性廻歸模型的換手預測、 MS與Serving BS或鄰近BS相對運動方向的判定方法、Candidate Target BS選擇的方法及應用前述方法的三種掃描機制。這三種掃描機制分別為(Scheme A)簡單周期性掃描 (Scheme B)有換手預測及預估線性迴歸線斜率輔助的非週期性掃描 (Scheme C)僅有預估線性迴歸線斜率輔助的非週期性掃描。
這三種掃描機制經過模擬與分析在相同換手成功率下以Scheme C的省電效能最佳，Scheme A，Scheme B次之，但均可在犧牲部份睡眠時間的情況下，達成兼顧MS的行動性及省電效能並減少佔用Serving BS的air interface資源的三重目的。

In the MAC layer of IEEE 802.16e, a power saving mode that is well known as sleep mode is defined to minimize MS power usage and decrease usage of Serving BS air interface resources. The behavior of each MS involved in sleep mode is restricted, and the operation of such a MS is much different to that in normal mode (i.e. no sleep.) It will significantly decrease the power efficiency of a MS to apply the neighbor base stations scan schemes which are normally used in normal mode.
In order to consider both mobility and power efficiency of a MS, this thesis proceeds to deal with these issues from three aspects: (1) let the MS be aware of when to scan, (2) providing the MS with workable scan schemes to be conducted in sleep mode, (3) reducing the scan frequencies. To fulfill the objectives mentioned above, this thesis introduces the improved handover prediction scheme by applying the simple linear regression model, a method which makes MS be able to sense the relative moving direction among Serving BS and neighbor base stations and the candidate target BS selection method. We propose three scan schemes, applying our introduced methods, and these scan schemes are: (1) Simple Periodic Scanning (Scheme A), (2) Non-periodic Scanning with Handover Prediction and the Slope of Estimated Linear Regression Line Support (Scheme B) and (3) Non-periodic Scanning just with the Slope of Estimated Linear Regression Line Support(Scheme C).
Through simulation and performance analysis, Scheme C presents high performance in power efficiency, while the performance of Scheme A and Scheme B is worst than Scheme C on the basis of the same HO successful rate. However, only sacrificing part of sleep time, the proposed three scan schemes can achieve the triple objectives of mobility, power efficiency and decreasing usage of Serving BS air interface resources.

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