As a mature and stable IoT technology, LoRa has developed rapidly and has formed a huge ecosystem. Its industrial chain includes terminal hardware manufacturers, chip manufacturers, module gateway manufacturers, software manufacturers, system integrators, network operators business, etc. With its technical characteristics such as low power consumption, long transmission distance, strong penetration, flexible networking, and easy deployment, as well as the characteristics of “self-organization, security, and controllability”, it has been widely used in epidemic prevention and control, medical health, smart agriculture and other fields. It is widely used in many fields such as animal husbandry management, smart buildings, smart parks, smart meters and energy management, smart cities, smart logistics and smart manufacturing.
What is LoRa #
The full name of LoRa is Long Range, which means long distance. It is a wireless digital communication modulation technology at the physical layer, also known as spread spectrum continuous frequency modulation modulation technology (Chirp Modulation). A low-power local area network wireless standard developed and promoted by semtech, which is characterized by spreading farther than other wireless methods under the same power consumption, realizing the unity of low power consumption and long distance, and at the same power consumption Compared with the traditional wireless communication radio frequency communication distance, the distance is expanded by 3-5 times.
LoRa’s networking method #
LoRa is only a modulation technology of the physical layer, and its networking mode can be selected differently according to different applications and needs. Commonly used in practical applications are: point-to-point, star, tree, mesh, Mesh and other networking forms.
LoRa’s network is flexible and convenient: on-demand deployment, planning and deploying the network according to application needs; according to the on-site environment, for the terminal location, reasonable deployment of gateways and terminal devices. The expansion of the network is very simple, and the coverage can be enhanced or expanded at any time according to the change of the node size. At the same time, LoRa can be independently networked: individuals, enterprises or institutions can deploy private/private networks, enterprise networks or industry networks (license-free frequency bands). Most IoT applications are regional, and small-scale networks can solve the problem. Regional local area networks are an effective and necessary supplement to the public network.
LoRa communication security #
Technical analysis of whether a data is safe can be analyzed through four aspects: the radio frequency physical layer, the data transmission process, the security encryption algorithm, and the application layer.
From the analysis of the physical layer, the security of data is mainly reflected in the strong concealment of the signal. Strong concealment is also called low detectability (LPI—LowProbability of Intercept), that is, it is not easy to be detected, and the interference to various narrowband communication systems is very small. As shown in the figure below, the data before spreading is above the noise floor, and its signal is very easy to detect. When the signal is spread spectrum, the signal is completely below the noise floor and cannot be detected by the energy intensity. This is also the reason why industries such as military industry and communications have been using spread spectrum technology as a means of communication.
Compared with the communication rate, the spread spectrum signal is expanded in a relatively wide frequency band, the power in the unit frequency band is very small, and the signal is buried in the noise, which is generally not easy to be found, and the concealment is better. Furthermore, because the spread spectrum signal has a very low power spectral density, it interferes little with the various narrowband communication systems used. In terms of security, LoRa technology also inherits the advantages of spread spectrum technology, and it is difficult for general equipment to detect and interfere with LoRa signals.
Among all IoT communication technologies, LoRa technology can demodulate 20dB under noise, while other IoT communication technologies must be higher than a certain level of noise to achieve demodulation.
The waveforms of other IoT communication technologies can be captured by devices such as spectrum analyzers. Likewise, these communication data may also be tampered with or falsified. The LoRa technology has good concealment and anti-interference characteristics, and has strong physical layer security characteristics.
From the analysis of the data transmission process, the data of the terminal equipment using the public network technology first reaches the base station, then reaches the mobile switching center, and finally reaches the operator’s cloud, and then the final data is forwarded to the client application or the client’s cloud. Data can be sent directly to the client without first sending it to the operator’s cloud. The LoRa data of the private network is directly collected and calculated locally, and the data will not even leave the scope of the park. The farther the data is transmitted, the more the number of transfers, and the higher the security risk. With the use of private network technology, the data can be completely stored locally, and the data is always in its own hands. Many government and enterprise networks implement network security through the isolation of internal and external networks. If a private network is used, it can directly connect to the original internal network of the government and enterprises, and the security level is very high. From the data transmission process analysis (network layer analysis) LoRa private network/private network has high security features.
From the analysis of data encryption method, the public network represented by mobile cellular network technology adopts the same encryption method for convenience and efficiency, so it is easy to be broken. Because of the ubiquity of the public network, it is impossible to do too many customized services for security, and it must balance between security and performance. The private network is completely different. They can be armed to become “armored vehicles” according to the needs of customers. The security encryption algorithm of data can do its best. For security, it can sacrifice data rate and cost, which is completely absent from the public network. of. LoRa technology is just a transparent transmission technology at the physical layer. Users can set up their own security engine at the link layer of the network layer, perform the most in-depth customization, and add a hard encryption chip. From the analysis of data encryption methods, it can be seen that the security of LoRa can be strongly guaranteed.
From the analysis of the application layer, users can encrypt according to the actual application requirements. Since LoRa has strong flexibility in the networking, the security management method on the application side can cooperate with the network layer and encryption algorithm to realize the overall security of the entire application.
