在本論文中，我們將研究一個低成本、低耗能的車用防盜通訊系統－VACS (Vehicle Anti-theft Communication System)，並加以實作及進行相關測試。VACS可以取代GSM通訊系統，讓車輛與外部週邊配件（如診斷器、遙控器）直接進行通訊，傳輸車輛狀態資訊及控制命令，而不需基地台等昂貴硬體建設介入傳輸，也因此不需負擔通訊月租費。 VACS係以IEEE Std 802.15.4TM – 2006 physical layer作為基礎，再加上自行研發的MAC layer及application layer，並儘量降低系統的複雜度，以節省開發時間和成本。 VACS利用duty periods來節省電源消耗。系統裝置在每一個固定時間區間內，只需視情況開啟transceiver一小段時間，其餘時間可關閉transceiver並進入low power mode。 VACS系統經實作驗證，有效傳輸距離可達135公尺以上。遙控器的待機時間長達40000小時，系統容量可供13333 users同時使用。成本方面，一套VACS硬體製造成本可控制在新台幣1000元以內。 In this thesis, we investigate a low cost and low power consumption communication system for vehicle anti-theft systems, “VACS (Vehicle Anti-theft Communication System)”. We also perform the hardware implementation and the related tests. VACS can replace the GSM system to communicate directly between the vehicle and its accessories (such as diagnostic device and remote control device), it can transmit vehicle status information and vehicle control command without the need of expensive infrastructures such as the base stations in GSM systems, and hence the users do not have to pay the monthly communication service fees. VACS is a system based on IEEE Std 802.15.4TM–2006 physical layer, the upper layers are self-defined MAC layer and application layer. We try to lower the complexity of the system in order to reduce the time and the cost of the development. VACS utilizes the duty periods to save power consumption. The devices turn on the transceivers only for a very short time in every fixed time interval, and turn off the transceivers to enter low power mode for the rest of the time. According to the test results of the hardware implementation, the effective transmission range of VACS is more than 135 meters. The standby duration of remote control device is up to 40000hrs. The system capacity can support 13333 users simultaneously. The cost of a set of VACS can be controlled under NT1000 dollars.
