（1）模塊工作電壓：本終端的工作電壓來源于車載電瓶，通常為 12V 或者24V，模塊電壓應小于電源電壓；
(1) Module working voltage: the working voltage of the terminal comes from the on-board battery, which is usually 12V or 24V, and the module voltage should be less than the power supply voltage;
(2) Communication mode: wireless network and short message communication can be used; (3) terminal online rate: in order to ensure the real-time data exchange between the terminal and the monitoring center, the terminal should maintain a high online rate;
(4) Packet loss rate: the packet loss rate refers to the ratio of the number of lost packets to the transmitted packets in the test. In order to reduce the packet loss rate, it can be considered in the design that when the wireless transmission module cannot connect to the network and the terminal cannot log in to the system, the data will be transmitted to the server after the wireless transmission module is out of the blind zone;
（5）定位精確度：車輛監控調度系統的電子地圖精度數量級是米，我國二級道路的標準寬度為 30~60m，如果要對車輛進行準確的監控，定位精度需控制在30m 以內，否則，當兩條道路的距離過近時，就可能出現定位錯誤，即正在某條公路上行駛的車輛被定為在道路外或其它道路上。
(5) Positioning accuracy: the order of magnitude of the electronic map accuracy of the vehicle monitoring and dispatching system is meters. The standard width of the secondary road in China is 30 ~ 60m. If the vehicle is to be accurately monitored, the positioning accuracy should be controlled within 30m Otherwise, when the distance between the two roads is too close, positioning error may occur, that is, the vehicle driving on a certain road is determined to be outside the road or on other roads.