【正文】
k it is not the economy, is unreasonable. This has helped wireless munications technology development in the field of remote monitoring. GPRS (General Packet Radio Service), as the existing GSM work evolution of the transition to the third generation mobile munication technology for (), with rapid access, always online, so by the flowmeter features Remote realtime data transmission in a sudden unmatched advantages. 2 GPRS technology GPRS (General Packet Radio Service) is based on the GSM mobile work systems, the use of packet 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