WAVE車間無線通訊系統之移動管理研究
Abstract
由於Wireless Access in Vehicular Environments (WAVE) 無線通訊協定的制定，無線通訊技術能實際的應用於交通環境之中，交通工具之間透過此一通訊協定相互進行無接縫式(seamless)的資料傳輸。在WAVE通訊協定中，資料可以透過WAVE Short Message Protocol (WSMP)進行傳輸，但是在規格書中，針對WSMP僅只提供廣播(broadcast)服務，對於點播(unicast)及群播(multicast)並沒有相對應的處理機制。欲處理WSMP之點播(unicast)及群播(multicast)資料傳遞服務，必需建立移動管理(mobility management)的機制，方能紀錄每一個使用者/交通工具之位置，以達成資料傳遞之目的。本計畫中，我們提出一套’以預測位置為基礎之移動管理機制’，此一機制將有效的利用全球定位系統(Global Positioning System； GPS)所提供之位置資訊，大量的降低維持移動管理機制所需之資料傳輸量。在車流量大且行駛速度快的快速道路/高速公路上，基於相同的呼叫成本(paging cost)，我們所提出的’以預測位置為基礎之移動管理機制’可以大幅減少40%~90%的移動管理資料傳輸量。
The Wireless Access in Vehicular Environments (WAVE) provides seamless and interoperable services for vehicles. In WAVE, the WAVE Short Message Protocol (WSMP) provides broadcast services but does not define unicast/multicast services that require mobility management to track the locations of the vehicles. To resolve this issue, we will propose a prediction-based mobility management mechanism by utilizing positioning systems (e.g., GPS) for a WAVE system deployed in highway environment with a large volume of high-speed vehicles. Our study indicates that under the same paging cost, our approach can reduce 40%-90% of the network traffic as compared with the traditional cellular mobility management approach.
The Wireless Access in Vehicular Environments (WAVE) provides seamless and interoperable services for vehicles. In WAVE, the WAVE Short Message Protocol (WSMP) provides broadcast services but does not define unicast/multicast services that require mobility management to track the locations of the vehicles. To resolve this issue, we will propose a prediction-based mobility management mechanism by utilizing positioning systems (e.g., GPS) for a WAVE system deployed in highway environment with a large volume of high-speed vehicles. Our study indicates that under the same paging cost, our approach can reduce 40%-90% of the network traffic as compared with the traditional cellular mobility management approach.