Principle, Usage and Characteristics of Lte cat 4 modem

Lte cat 4 modem is mainly used for wireless data transmission. Moreover, it is through long-distance wireless data transmission, and the objects of transmission are equipment and data centers or equipment.For example, the sensor that collects the temperature is placed in a factory outside the city. Now the demand is that the data can be seen on the home computer in the city, so the data has to be transmitted to the server, and then realized through the computer.The process of transmitting data to the server is called data transmission, which is realized by LTE cat 4 modem.

The Lte cat 4 modem obtains data by connecting the terminal equipment through the interface, and then transmits the data wirelessly through the operator network (2G/3G/4G) to the designated data center or equipment. At the same time, the reverse data center can also send data or instructions to the LTE cat 4 modem through the operator network, and then the LTE cat 4 modem sends them to the terminal equipment through the interface.

What is Lte cat 4 modem?

The data transmission unit LTE cat 4 modem is a wireless terminal device specially used for converting serial port data into IP data or converting IP data into serial port data for transmission through a wireless communication network.Broadly speaking, during communication, the module unit responsible for sending data information at both ends of the link for data transmission is called LTE cat 4 modem, which converts the format of the transmitted information and collates and checks the data. In a narrow sense, LTE cat 4 modem generally refers to the lower 4G transmitting terminal equipment in wireless communication. The former is a module, while the latter is a device.The following description refers to the latter (lower transmitting terminal equipment) unless otherwise specified.

What are the terms related to Lte cat 4 modem?

(1) What are the upper and lower computers?

The upper computer and the lower computer are a relative concept. In communication, there is a pair of devices with master-slave relationship. The terminal device responsible for submitting information is the lower computer, and the device responsible for processing the submitted information is the upper computer.In most cases, the LTE cat 4 modem device belongs to the lower computer, and the data center that is responsible for processing the information returned by the LTE cat 4 modem is the upper computer. The typical application mode is that multiple LTE cat4 modems correspond to one data center.However, the upper computer and the lower computer do not necessarily correspond to each other. They can be one lower computer corresponding to one or more upper computers, or one upper computer corresponding to one or more lower computers. The specific correspondence depends on the application.

(2) What is a data center?

Data center refers to the upper computer system which collects, summarizes and processes the information returned by the lower computer, and controls and manages the lower computer to a certain extent. It includes complete computer hardware equipment and specific complete software functions.

(3) What is fully transparent transmission?

Transparent transmission is a simple process of sending IP packets without any operation or change.Generally speaking, during fully transparent transmission, the format and content of the data do not change before and after transmission. The data received by the remote data center is the same as the data collected on site. The data does not change during transmission. If there is any operation or change in the IP packet, it is not fully transparent.

How does the Lte cat 4 modem work?

The communication between the LTE cat 4 modem and the server is initiated by the 4G LTE cat 4 modem side (client), which responds to the LTE cat4 modem side by sending back feedback or accepting communication. Lte cat 4 modem and server form an application system based on 4G network communication.Compared with the LTE cat 4 modem side, the server side is installed with a more complex application program, which can accept any communication request initiated by the LTE cat 4 modem side and detect the communication status in the link at all times, so as to realize real-time data acquisition, database services and other applications.

Four core functions of Lte cat 4 modem

1. Support automatic heartbeat and keep online forever.

2. Provide bidirectional conversion function of serial port data

3. Internally integrated TCP/IP protocol stack

4. Support parameter configuration and permanent saving

What do I need to do to prepare for the Lte cat 4 modem test?

Before testing the Lte cat 4 modem, the following conditions are required:

(1) a public IP address or an independent domain name;

In some cases, the computer in the test environment cannot have an independent public network IP address and domain name address because it is in the internal LAN, so it is necessary to obtain an independent public network IP through dial-up Internet access, or set DMZ host mapping or port mapping on the router in the test environment to enable the computer to penetrate the internal network.So that the computer and the Lte cat 4 modem can answer normally.

(2) a SIM card with 4G data service (required for testing 4G Lte cat 4 modem), or a UIM card with 4G data service;

(3) a desktop or laptop computer with a 9Pin RS232 serial port (or USB to TTL);

This computer is used to set and adjust the parameters of the LTE cat 4 modems. At the same time, when testing, it can connect the LTE cat 4 modem as a virtual data source device, and send and receive data with the host computer data center through the serial debugging tool. Of course, this computer can be both the data center of the upper computer and the lower computer of the virtual data source when condition 1 is met. But in the second test purpose, try to avoid doing so, so as not to doubt the test itself.

4G LTE cat 4 modem covers 2G/4G/NB-IOT, which can adapt to the interconnection needs of various equipment scenarios, with strong compatibility and adaptability, and is widely used in the industry. Lte cat 4 modems independently developed by the company have been applied in the field of industrial Internet of Things, automatic water sales in residential areas, the power industry, intelligent retail, and other fields, promoting the application of Internet of Things scenarios.