Four positioning technologies for the Internet of Things

First, WIFI positioning technology

每个无线AP都有globally unique MAC address, and generally speaking, wireless APs will not move for a period of time. When Wi-Fi is turned on, the device can scan and collect surrounding AP signals, whether or not Encryption, whether it is connected, or even the signal strength is not enough to display in the wireless signal list, can get the MAC address broadcast by the AP.

Second, Bluetooth positioning technology

Based on the RSSI (Signal Strength) value, positioning is performed using the principle of triangular positioning.

Network-side positioning: Beacon, smart terminal, Bluetooth gateway, server (location engine, database), etc. When the smart terminal enters the coverage of the Beacon signal, the received RSSI value is uploaded to the server through the Bluetooth gateway, the positioning engine processes it, and it can be managed and checked in the management background.

Terminal-side positioning: Beacon, mobile terminal, server (location engine, database), etc. When the mobile terminal enters the coverage area of the base station, the RSSI (signal strength) value received by the mobile terminal is measured by the built-in positioning algorithm to determine the specific location, and the map engine is used for display and navigation operations.

Third, RFID indoor positioning technology

无线电频率识别室内定位technology uses radio frequency method. The fixed antenna adjusts the radio signal into an electromagnetic field. The tag attached to the article generates an induced current after the magnetic field and transmits the data. The data is exchanged through multiple pairs of two-way communication to achieve the purpose of identification and triangulation. Radio frequency identification indoor positioning technology has a short working distance, but it can obtain centimeter-level positioning accuracy information within a few milliseconds. Due to the non-line-of-sight advantages of electromagnetic fields, the transmission range is large, and the size of the mark is relatively small and the cost is relatively low.

Fourth, base station positioning technology

Base station positioning can be roughly divided into three types from the principle of positioning calculation: positioning technology based on triangulation and operation, positioning technology based on scene analysis, and positioning technology based on proximity relationship. It is mainly to estimate the position of a moving target by using the change of signal attenuation caused when the moving target approaches or moves away from the base station. If the signal power from a moving target is known, then when measuring the signal power at another point, a certain propagation model can be used to estimate the distance between the moving target and that point.