GPRS, also called General Packet Radio Service, is the first step in the evolution of the GSM system to the third generation of mobile communications, so GPRS is also described as “2.5G”. GPRS makes full use of shared wireless channels, uses IP Over PPP to realize high-speed and remote access of data terminals, and provides end-to-end, wide-area wireless IP connections.
The networking method of the GPRS module is relatively simple. The GPRS module can be directly connected to the user equipment through the RS232 or RS485 interface.
GPRS module access: Users can choose CMNET and APN to access the network. CMNET is usually used for public users; APN is aimed at industry users, usually in a group, and users need to set a username and password, which has better security. In addition, APN users can apply to bind a fixed IP address to the mobile intranet.
The networking of the data center is slightly more complicated, and the choice of networking form is mainly determined by the amount of business data, reliability requirements, data confidentiality, and network conditions.
Internet access method (the monitoring center accesses the wireless network via the Internet)
The enterprise has stable and permanent access to the Internet; the router port address on the enterprise side and the IP address of the monitoring center should be public and provided by the ISP that provides Internet connections to the enterprise. For this solution, customers must first contact the Internet operator The business owner applies for a fixed IP on the public network. The center uses a fixed IP address on the public network, and the monitoring points directly initiate connections to the center. Or the client company has a server connected to the Internet and has a fixed public IP. However, considering the stable operation of the server, other application software is usually not allowed to be installed on the server, so the GPRS data center system cannot be installed on the server. You can use NAT port mapping to solve this problem.
Dynamic domain name resolution
When using dynamic DNS, there are several things to prepare first. The first is Domain Name, which requires applying for a set of third-level domain names or second-level domain names. The second is that you need to go to the domain management center to specify the dynamic DNS service. When the preparation work is completed, a Client software will be obtained from the domain management center to maintain the dynamic IP and Domain Name. When the computer in the data center is turned on, the dynamic IP can be obtained from the ISP, and then the client software can be used to maintain the dynamic IP and Domain Name. The DDNS server goes online and refreshes the domain name and IP comparison. The GPRS terminal can interpret the positive and negative Domain Name through DNS, and then establish a connection.
Dedicated line access method (the monitoring center accesses the wireless network through DDN dedicated line)
This solution is suitable for enterprises that do not have access to the Internet or that have high security concerns, and are suitable for use in industries such as finance, securities, and industrial monitoring. Enterprises access China Mobile’s routers through dedicated lines, and the client’s access router must provide a public IP address. .
GPRS MODEM access method (the monitoring center acts as a data terminal bound to a fixed IP address)
This solution is suitable for enterprises that do not have access to the Internet and have extremely high security requirements; it is suitable for applications that do not require a large total data bandwidth, such as data collection systems using the Polling transmission protocol; all data runs within the GPRS network; all GPRS Terminals can communicate directly with each other; the GPRS data terminal access point in the data center is bound to a fixed IP address. (That is, provide at least one SIM card bound to a fixed IP address)
The above is the specific content of GPRS module networking . I hope it will be helpful to everyone!