GPRS DTU wireless transmission

Analysis of the working process of GPRS DTU wireless transmission

GPRS DTU is a wireless data terminal with Internet of Things technology. It uses public operator Internet GPRS Internet (called G network) to show customers the role of wireless network for long-distance data transmission. It selects high-performance industrial 8/16/32-bit communication CPU and Industrial wireless module, with embedded real-time operating system as the support point service platform of mobile phone software, and showing RS232 and RS485 (or RS422) sockets, which can be connected to serial devices immediately, keeping the statistical data fully transparent transmission function.

The most basic method of using GPRS DTU is:

Put a GPRS-enabled sim card in the DTU. After the DTU is powered on, first apply for registration to the GPRS Internet, and then establish a connection based on the GPRS Internet and the data processing method base.

After the GPRS DTU is powered on, it is the first to read the main working parameters stored in the internal FLASH (including the main parameters of GPRS dialing, serial port baud rate, data center ip address, etc., which have been equipped beforehand).

GPRS DTU wireless transmission process:

1. GPRS DTU logs on to the GSM Internet, and then starts GPRS PPP dialing.

After the dial-up is successful, GPRS DTU will get an internal ip address randomly assigned by the mobile.

In addition, GPRS DTU is in the mobile internal network, and the ip address of the network is generally not fixed, and changes with each dialing.

People can understand that GPRS DTU at this time is a mobile internal local area network machine equipment, according to the mobile gateway ip to maintain the communication with the external Internet internal network ip. This is similar to the method of browsing the external Internet based on the gateway ip on a computer in a local area network.

2. GPRS DTU actively carries out the communication connection with the data center and maintains the communication connection always exists. Because GPRS DTU is in the mobile intranet, and the ip address is not fixed.

Therefore, only the GPRS DTU actively connects to the data center, and the data center cannot actively connect to the GPRS DTU.

This stipulates that the data center has a fixed intranet ipip address or a fixed domain name registration.

The internal network ipip address or fixed domain name registration of the data center is stored in the GPRS DTU as the main parameter, so that once the GPRS DTU is successfully connected to the data center, it can be actively connected to the data center.

3. Practically speaking, GPRS DTU makes TCP or UDP communication requests to the data center based on the main parameters such as the ip address of the data center and its server port.

After receiving no response from the base, GPRS DTU feels that the handshake with the base has been successful, and then maintains this communication connection to exist. If the communication connection is terminated, GPRS DTU will immediately shake hands with the base again.

Because the TCP/UDP communication connection has already been established, two-way communication of statistical data can be carried out.

4. As far as DTU is concerned, if two-way communication with the data center is established, it will be relatively easy to perform the conversion of client serial statistics data and GPRS Internet data files.

Once receiving the client's serial port statistics, DTU immediately encapsulates the serial port statistics in a TCP/UDP packet and sends it to the data center.

On the contrary, when DTU receives the TCP/UDP packet from the data center, it will remove the statistical data content from it, and immediately send it to the customer's machine equipment according to the serial port.

According to the wired data collection base, it also carries out two-way communication with many GPRS DTUs.

It is the more common method in the GPRS DTU software system at this stage.

The above is the analysis of the working process of GPRS DTU wireless transmission.