The 4G cellular modem general radio packet service (4G cellular modem) is a wireless packet switching technology based on the 4G system,Provides end-to-end, wide-area wireless IP connectivity.The 4G cellular modem makes full use of the shared wireless channel and adopts IP Over PPP to realize the high-speed remote access of the data terminal.As the transition technology (2.5g) from the existing GSM network to the third generation mobile communication, 4G cellular modem has significant advantages in many aspects.
The networking of 4G cellular modem wireless monitoring system is relatively simple.The 4G cellular modem can be directly connected to the user equipment through an RS232 or RS485 interface.
Data terminal (4G cellular modem) access: 4G cellular modem users can select CMNET and APN to access the network.CMNET is usually used for public users, APN is used for industry users, usually in a group, users need to set user name and password,Security is better. In addition, APN users can apply to bind the fixed IP address of the mobile intranet.
The network in the data center is a bit complicated.For the application field of 4G cellular modem, we provide data center networking solutions in various application forms for developers' reference.The choice of network form mainly depends on the amount of service data, reliability requirements, data confidentiality and network conditions.
This scheme is suitable for enterprises that can not access the Internet and have high security requirements.It is suitable for applications that do not require high data bandwidth, such as data acquisition systems that use polling transmission protocols.All data runs on a 4G cellular modem network.Require direct communication between all 4G cellular modem terminals; Fixed IP address of 4G cellular modem data terminal access point in data center.(I.e. At least one SIM card with a fixed IP address)
Enterprises have stable and permanent Internet access;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 connectivity for the enterprise.In this case, the customer should first apply to the Internet operator for the fixed IP of the public network.The center uses the public network fixed IP, and the monitoring point directly initiates the connection to the center.Or the client company has a server connected to the Internet and has a fixed public network IP.However, considering the stable operation of the server, it is usually not allowed to install other application software on the server.Therefore, a 4G cellular modem data center system cannot be installed on the server.
The scheme has good real-time performance and stability, but the cost of using public network fixed IP is high.
This kind of scheme is suitable for enterprises that can not access the Internet or consider high security, and is suitable for financial, securities, industrial monitoring and other industries.When the enterprise accesses the China Mobile router through the dedicated line, the client access router must provide the public network IP address.
For the application system without fixed IP, the networking mode is the same as "fixed IP access". The key to solving the problem lies in the data center.There are currently two solutions:
When the IP address of the data center changes, the central terminal can notify the terminal equipment of the latest IP address,And notify that connection through a short message. SMS can be sent via Internet or USB port 4G cellular modem.
Some preparation is required when using dynamic DNS.
The first is the domain name. You need to apply for a set of third or second level domain names.
Second, you need to go to the domain management center to specify the dynamic DNS service.
After the preparation is completed, a Client will be obtained from the domain management center software to maintain the dynamic IP and domain name.When the data center computer is turned on, you can get a dynamic IP from your ISP.The domain name and the IP control are refreshed online through the Client and the DDNS server software again,The 4G cellular modem terminal can positively and negatively interpret the domain name through DNS and then establish a connection.
The 4G cellular modem provides the following types of applications:
Transportation: vehicles and intelligent scheduling.
Finance, securities and commerce: wireless POS, wireless ATM, vending machines, mobile banking, etc.
Real-time release of stock market trends, weather forecasts, traffic information and so on.
Public safety industry: access remote databases anytime, anywhere.
Telemetry, remote sensing, remote control: such as meteorological and hydrological system data acquisition, disaster telemetry and early warning, remote operation.
Provide VPN services to enable enterprise employees to keep in touch with headquarters anytime and anywhere, and reduce the cost of self-built WAN.
It provides network application services based on 4G cellular modem and various applications based on WAP.
Check the inventory and turnover of vending machines through mobile phones or computers.
