在無線網路環境中，我們期望無論何時何地都能接收各種媒體的服務。而有效地作位置追蹤（location tracking）機制則是達成此期望的關鍵之一。明確的說，位置追蹤機制是用來追蹤可動式平台（mobile station）的系統架構。
本論文的主要目的在於針對可動式平台的移動行為設計有效的位置更新報告（location update）機制來追蹤可動式平台。本機制將時間式策略（time-base strategy）與距離式策略（distance-based strategy）融合為混合式策略（mixed mode strategy）。在本機制中，系統能根據位置更新報告的訊息推算出可動式平台之後的移動資訊，包含了接下來該平台會前往的位置及居留時間，並將這些資訊組成名冊（list）回傳給該平台。藉由在系統與可動式平台同時存放相同名冊的方式，我們可以根據時間因素縮小當通話來時所需尋找的廣播區域（page area）。在妥善推算下產生的名冊可以使整個位置追蹤機制達到良好的成效。此外，我們根據可動式平台往往長時間停留於特定區域的狀況，將距離式策略加以小部份修改，再加到我們提出的混合式策略中使用。最後，考量系統與可動式平台皆已知何處是特定長時間居留區域的情境，將我們的混合式策略加以調整，則可減少不必要的位置更新報告。
效能評估報告在本論文中以程式模擬的方式進行，討論在各種不同的可動式平台移動行為（mobility behavior）下所得到的效能，並與距離式策略或歷史式策略（history-based strategy）作比較。根據模擬結果本論文確實能有效提昇位置追蹤機制的效能。

We investigate feasible location tracking scheme that integrates time-based and distance-based location information for a class of mobile stations (MSs) with regular mobility patterns. The proposed schemes are able to yield performance gain through reducing paging cost with a slight increase in location update rate. This effect is achieved by exploiting predictable time and location information from mobility regularity of an MS and utilizing the information both at the network and the MS. Essentially, the technique requires the network to keep an updated list of location area identifications (LAIs) and relative dwell times for a targeted MS and send it to the MS during location update. If the MS violates the time constraint in a location area or runs out of listed LAIs, location update is performed. For call delivery, the technique allows the network to locate the called MS in a paging zone restricted to a subset of listed LAIs according to call arrival time. We found that for an MS with regular mobility behaviors most of time, the proposed scheme yields the most benefit. In addition, for MSs with occasional irregularity of mobility, the proposed scheme integrated with distance-based location update is able to take advantage of timely benefit from each mobility behavior all the time. Furthermore, we extend the proposed scheme by embedding user-specific location information in order to reduce potentially one unnecessary location update.

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