bluetooth sig bluetooth sig held a press conference in beijing, detailed introduces the bluetooth technology alliance of the bluetooth core specification core specification 5.1 content and technical details, and the new bluetooth core specification v5.1 introduces long-awaited "to find" function, this new function can help to clear the direction of the bluetooth signal device, thereby helping to develop cm-level real-time positioning and indoor positioning bluetooth solutions, this is a major breakthrough in the technology!
at present, high-precision indoor positioning needs a lot, such as through the navigation software navigation to find the hotel door, but the last 100 meters is also very critical, bluetooth homing function can solve this problem, from the hotel door can direct navigation to the guest room! in addition, this function has great potential in indoor searching, logistics and storage.
bluetooth technology is applied widely, from audio transmission and data transmission to location services, equipment, network areas are covered, and starting from 2016, bluetooth has become mobile phone standard, bluetooth technology has now extended to the tablet, automotive, audio entertainment devices, connected devices, intelligent building, smart home, intelligent industrial, smart city and so on, to predict a bluetooth device shipments will increase from $2018 in 4 billion to 2022 in 5.2 billion.
currently, location based bluetooth service solutions typically fall into two categories: proximity solutions and location systems. today, proximity solutions can use bluetooth to interpret when two devices are close to each other and an approximation of how far apart they are. this category includes both object-tracking solutions (such as personal property tags) and landmark information solutions (such as neighborhood awareness beacons).
in the future, bluetooth will be widely used in emerging fields, such as homing function, which will inspire many new applications. by 2022, bluetooth shipments based on location services are expected to reach 400 million!
principle of bluetooth homing technology
at present, the proximity and positioning solutions used by bluetooth are mainly based on rssi(received signal strength indication based on received signal strength indication) positioning, such as ibeacon positioning technology, which is generally used to transmit signals by beacon, receive signals by bluetooth device positioning and feedback signals. when the user enters, exits or lingers in the area, the beacon broadcast has the ability to carry on the transmission, can calculate the distance between the user and the beacon (can be calculated by rssi), from which we can know that as long as there are three can be located but its positioning accuracy can only reach the meter level.
how does bluetooth core specification 5.1 improve the accuracy to the centimeter level?
homing is not a new technique, its basic principle is to use radio phase difference to convert position information. in bluetooth 5.1, mainly adopts two kinds of positioning technology, one is using the arrival angle (angle - of - concatenated: aoa) measurement technology, is through the test to direction of the transmitters and receivers directly and through triangulation location and distance of emitter and purpose become technology, mainly for rtls (real-time positioning system (gps), items, tracking and landmark information.
its working principle is the transmitter send special data packets through a single antenna, the receiver has to multiple antenna array configuration, because the distance of the antenna to the transmitter is different, and thus the antenna will find that the received signal phase difference, when switching between active antenna, after obtaining the iq sample from the received signal through the calculated data signal of relative orientation. aoa is also suitable for reverse tracking, medical device management, etc.
there is a way is to use the departure angle (angle of departure) measurement, and using the signal phase difference technology, mainly for indoor positioning system (ips), it is the working principle of the emitter in to switch between active antenna array configuration, send special data packet, the receiver through a single antenna signal, and then from the received signal in iq samples, after know the antenna configuration in the transmitter, relative direction and distance of the signal through the calculation of data, the direction finding technology is suitable for indoor items management, logistics, warehousing, etc.
by introducing new homing capabilities, the bluetooth proximity class solution will be able to add features related to the device's orientation. for example, an item-tracking solution will not only inform the user of the location of an approaching property tag, but also give the user an idea of where they are going, significantly improving the user experience.
the positioning system can use bluetooth to determine the physical location of the device, such as real-time positioning system that can be used for asset tracking and indoor positioning system that can be used for indoor navigation. by adding a new homing feature, such a system can improve position accuracy to the centimeter level.
what else can orientation inspire?
the addition of bluetooth homing is expected to spur many innovative applications, such as enabling cars to open automatically via mobile phones. installed in the car locator, determine the angle of the driver, if it has already been to the front of the car can automatically open the door, and can also be used in the entrance guard system, through the angle of whether qualified personnel is close to the gate to open and close automatically, in addition, the bluetooth technology has achieved mesh network topology, such as many hotels or the building has been in use for mesh lighting lamps and lanterns and switch, the node can be a natural have sought to function aod transmitter or aod receiver, this integration can inspire a lot of innovation, the future will be a lot of this aspect of the fusion.
currently, some manufacturers are developing bluetooth modules that meet the bluetooth 5.1 standard, such as shenzhen xinta. bluetooth 5.1 enables precise positioning through the characteristics of arrival angle and departure angle, opening up new opportunities for accurate indoor positioning devices such as building access control and remote keyless unlocking system.