DTU working principle, DTU transmission method?

DTU working principle, DTU transmission method?

DTU concept introduction

What is the DTU in the Internet of Things? The Chinese name of DTU is "wireless data transmission terminal". According to the different transmission methods and networks used in data transmission, DTU devices can be divided into many types, such as: 4G DTU, NB-IOT DTU , LORA DTU, GPRS DTU.

Among them, 4G DTU is a wireless data transmission terminal that uses 4G network for data transmission. Nowadays, with the continuous development of the Internet of Things industry, more and more manufacturers of Internet of Things equipment are produced. Different manufacturers use 4G DTU equipment according to different needs. Different functions are integrated.

 How DTU works

The communication between the DTU and the server is initiated by the GPRS DTU (client), and the server responds to the DTU by sending back feedback or accepting communication. The DTU end and the server end together form an application system based on GPRS and INTERNET network communication. Compared with the DTU side, the server side is equipped with more complex applications, which can accept any communication request initiated by the DTU side and detect the communication status in the link at any time, so as to realize real-time data collection, database services and other applications.

The DTU side needs to know the IP address and port number of the server in advance before it can initiate a communication request. Once the communication is established, there is no difference between the server side and the DTU side.

The IP address of the server can be either a public IP (fixed IP) or a dynamic domain name obtained through a domain name resolution server.

The port number of the server usually corresponds to the specific application running in the server. For example, the port number TCP 21 is used by the FTP service, and TCP 80 is used by the hypertext server (Http). That is, the application on the server side supports sending and receiving data through a specific port number.

 DTU transmission mode

There are mainly the following communication methods between DTU and data center:

1. The data center has a fixed public IP: DTU uses the network provided by the operator to directly send a connection request from the monitoring point to interact with the data center. This method is reliable and stable.

2. Data center dynamic public network IP: Since the dynamic IP is used, the IP obtained by the data center is random, and the monitoring point cannot directly find the data center. Therefore, there needs to be a way for the monitoring point to find the data center. This way The domain name binding method is used.

By binding the domain name, the monitoring point finds the current IP of the data center through domain name resolution. This method saves broadband costs, but the connection status is controlled by the domain name server, which is suitable for small-scale monitoring.

3. The center adopts APN private network: all points use fixed IP in the internal network. This solution is that the customer center connects to the mobile company GPRS network through the APN private line, and the monitoring point is connected to the data center with a private fixed IP address. This way of data The security is high, but the cost is high and the application is complicated, most of which are used for super-large data monitoring.