RF wireless module is a kind of module that uses wireless technology for wireless transmission. It is widely used in computer wireless network, wireless communication, wireless control and other fields. The wireless module is mainly composed of transmitter, receiver and controller.

　　LoRa is one of the low-power WAN communication technologies. It is a kind of ultra-long-range wireless transmission technology based on spread spectrum technology adopted and promoted by Semtech. It is a unique modulation format generated by Semtech's RF part. LoRa RF part The core chips are the SX1276 and SX1278. These chips are small in scale and high in efficiency, bringing high reception sensitivity to LoRa wireless modules.

　　
The conventional digital data communication principle is to use as small a bandwidth as possible in accordance with the data rate. This is because the number of bandwidth is limited and there are many users to share. The principle of spread spectrum communication is to use the maximum amount of bandwidth as much as possible, and the same energy is transmitted over a large bandwidth. Here, a small portion of the spread spectrum bandwidth interferes with conventional wireless signals, but conventional wireless signals do not affect the spread spectrum signal because the bandwidth is narrow compared to conventional signals. For example, the LoRa spread spectrum transmission technology 170MHz E32-170T30D module has almost twice the transmission distance and penetration capability than the traditional FSK, GFSK and other modulation methods.

　　The E32-170T30D module operates at a frequency of 170MHz. The lower the frequency, the longer the wavelength and the smaller the propagation loss. Therefore, it has a strong penetrating diffraction capability and is suitable for more complicated environments. Compared to the E32-433T30D module with a frequency of 433MHz, the signal loss is significantly lower after passing through the four walls.

　　Antenna gain

　　Antenna gain is the ratio of the power density of the signal produced by the actual antenna at the same point in space as the ideal radiating element, under the condition of equal input power. Antenna gain is not only one of the most important parameters of the antenna, but also important for the operation quality of the wireless communication system. By increasing the antenna gain, the signal coverage in a certain direction can be increased, or the range is unchanged, but within the range. The signal strength is enhanced. Therefore, the higher the antenna gain, the better, and the smaller the standing wave ratio, the better.

　　FEC forward error correction

　　The FEC forward error correction code is a method to increase the reliability of data communication. In a one-way communication channel, once an error is found, its receiver will not have the right to request a transmission. FEC is a method of transmitting redundant information using data. When an error occurs in the transmission, the receiver is allowed to reconstruct the data. The FEC error correction function on the software can greatly improve the anti-interference ability, and the coding efficiency is high, and the error correction capability is strong. In the case of sudden interference, the interfered data packet can be actively corrected, and the reliability and the transmission distance are greatly improved; In the absence of FEC, such packets can only be discarded. The module has data encryption and compression capabilities. The data transmitted by the module in the air is random, and the data interception is meaningless through strict encryption and decryption algorithms. The data compression function has the probability of reducing the transmission time, reducing the probability of interference, improving reliability and transmission efficiency.

　　The air speed should be as low as possible, the higher the airspeed, the closer the communication distance, and the higher the packet loss rate.

　　RF wireless module is a kind of module that uses wireless technology for wireless transmission. It is widely used in computer wireless network, wireless communication, wireless control and other fields. The wireless module is mainly composed of transmitter, receiver and controller.

　　LoRa is one of the low-power WAN communication technologies. It is a kind of ultra-long-range wireless transmission technology based on spread spectrum technology adopted and promoted by Semtech. It is a unique modulation format generated by Semtech's RF part. LoRa RF part The core chips are the SX1276 and SX1278. These chips are small in scale and high in efficiency, bringing high reception sensitivity to LoRa wireless modules.