What is a Wireless Sensor Network (WSN) and where is it mainly used? Here, we will briefly introduce several concepts related to Wireless Sensor Networks.

1. WSN (Wireless Sensor Networks) is a distributed sensing network whose terminals are sensors capable of perceiving and inspecting the external world. Sensors in a WSN communicate wirelessly, allowing for flexible network setup and easy changes in device locations. They can also connect to the Internet via wired or wireless methods. It forms a multi-hop self-organizing network through wireless communication.

2. WS (Wireless Sensor) consists of modules encapsulated within a housing. When in operation, it is powered by a battery or vibration generator and forms a node in a wireless sensor network. These微型节点, randomly distributed and integrated with sensors, data processing units, and communication modules, form a network through self-organization. They can collect digital signals from devices and transmit them wirelessly through the sensor network to a wireless gateway at the monitoring center, which then sends the data directly to a computer for analysis and processing. If needed, wireless sensors can also transmit the entire time history of collected signals in real-time. The monitoring center can also wirelessly transmit control and parameter setting information to the nodes through the gateway. The data conditioning, acquisition, and processing module amplifies and filters the weak signals output by the sensor, sends them to an analog-to-digital converter, converts them into digital signals, and sends them to the main processor for digital signal processing to calculate the sensor’s RMS value, displacement value, etc.

3. DTU (Data Transfer Unit) is a wireless terminal device specifically used to convert serial data to IP data or IP data to serial data for transmission over a wireless communication network.

4. RTU (Remote Terminal Unit) is a remote terminal control system responsible for monitoring and controlling field signals and industrial equipment. An RTU is a core device in enterprise integrated automation systems, typically consisting of signal input/output modules, microprocessors, wired/wireless communication devices, power supplies, and housings. Controlled by a microprocessor and supporting network systems, it uses its software (or intelligent software) system to ideally enable the enterprise’s central monitoring and dispatch system to perform telemetry, remote control, remote signaling, and remote adjustment functions on primary instruments at the production site.

5. GPRS (General Packet Radio Service) is a mobile data service available to GSM mobile phone users and belongs to the data transmission technology of second-generation mobile communications. GPRS can be seen as an extension of GSM. Unlike previous continuous channel transmission methods, GPRS transmits data in packets. Therefore, users are charged based on the data units transmitted rather than using the entire channel, theoretically making it cheaper. The transmission rate of GPRS can be increased to 56 or even 114 Kbps.

6. ZigBee is a low-power local area network protocol based on the IEEE 802.15.4 standard. According to international standards, ZigBee technology is a short-range, low-power wireless communication technology. The name (also known as the ZigBee protocol) is derived from the waggle dance of bees, which communicate the location of pollen to their companions by flying and vibrating their wings (“zigzagging”). In other words, bees rely on this method to form a communication network within the group. Its characteristics include short-range, low complexity, self-organization, low power consumption, and low data rates. It is mainly suitable for automatic control and remote control applications and can be embedded in various devices. In short, ZigBee is an inexpensive, low-power, short-range wireless networking communication technology. ZigBee is a wireless network protocol for low-speed, short-range transmission. The ZigBee protocol consists of layers from bottom to top: the Physical Layer (PHY), Media Access Control Layer (MAC), Transport Layer (TL), Network Layer (NWK), and Application Layer (APL). The Physical Layer and Media Access Control Layer comply with the IEEE 802.15.4 standard.

7. Modbus Protocol is a common language used on electronic controllers. Through this protocol, controllers can communicate with each other and with other devices via networks (such as Ethernet). It has become a general industrial standard. With it, control devices produced by different manufacturers can be connected into an industrial network for centralized monitoring. This protocol defines a message structure that controllers can recognize and use, regardless of the network over which they communicate. It describes the process by which a controller requests access to other devices, how to respond to requests from other devices, and how to detect and log errors. It establishes a common format for the structure and content of message fields.