外文资料翻译---基于gprs远程监控系统数据终端的研究(编辑修改稿)

外文资料翻译---基于gprs远程监控系统数据终端的研究(编辑修改稿)内容摘要：

switching technology, patible with GSM, and highspeed data transmission works, GPRS in the GSM work to introduce a traditional three new ponents : PCU (Packet Control Unit, a control unit). SGSN (Serving GPRS Support Node. GPRS service node support) and GGSN (Gateway GPRS Support Node. Gateway GPRS support node) with the following characteristics : The high utilization rate of resources to the introduction of the GPRS packet switching mode of transmission, Only users send or receive data only during the occupation of resources This means that many users share the same wireless munications and high efficiency, thereby increasing the utilization of resources. GSM circuit switched data transmission methods and models for the entire link period, Whether users transmit data alone will occupy Channel. GPRS Billing users by the flow of data munications for the accounting standards. GPRS data transmission speed of highspeed transmission attainable Access to wait for a short time GPRS access time is short, fast connectivity, the average 2s. Online users will provide realtime line and online at the initial state, which will visit service is very simple and rapid. GPRS supports IP and support of the most widely used Inter IP and X . 25 agreement, but because of GSM work coverage, makes GPRS will provide Inter and other wireless access to a global work. GPRS features can be seen from the above, the GPRS work is particularly suited to the frequent smallvolume data transmission. Industry Remote Data Acquisition System is a relatively small volume of data typical of the realtime frequency transmission system. 3 System Design system structure Overall system structure like chart 1 shows. Serial or user terminal equipment to connect to GPRS wireless data terminals, and then labeled as IP packet data. GPRS air interface to access through GPRS work Gateway Routing and eventually arrived at through various data centers. terminals hardware design Data Terminal Equipment GPRS Data Terminal Inter GPRS work Data Center Equipment System structure GPRS data terminal hardware modular design, include the dataprocessing module, remote munication module. analogdigital conversion module and display module, the system structure is shown in figure 2. Data processing module contains AT89C55[3], X25045 two chips, AT89C55 for dealing with longrange munication modules, analog / digital converter module and the module data transmission. To ensure that data will not be lost restart. Serial E2PROM X25045 device used。