Satellite positioning indoors is not seen, 5G, UWB and Bluetooth are three centimeters high precision
5G, UWB and Bluetooth
In daily life, most of the information stream we receive contains spatial location information, and accurate acquisition of location information has become one of the necessary requirements for production and life. Especially in indoor environments with weak GPS or Beidou signals, there is an urgent need for higher-precision positioning technology to supplement location information. At present, 5G, UWB and Bluetooth technologies are all pursuing high-precision positioning, and each has its own advantages and disadvantages. Will the future high-precision positioning market be the only one, or will many complement each other? Let's analyze the development status and potential of the three.

5G positioning towards the centimeter level

5G is not just a communication network. The positioning network is also one of its highlights. With the overall promotion of 5G globally, the high-precision positioning of 5G is no longer a false proposition. 5G positioning is to measure wireless signals through a 5G mobile communication network to determine the geographic location information of the terminal. In the 3GPP R16 agreement, based on the large bandwidth characteristics of 5G, the 5G positioning capability can reach an accuracy of 80% for indoor 3 meters and 80% for outdoor 10 meters. Through technologies such as multi-base station RTT, AoA/AoD, TDOA, and single-base station UL-AoA, R16 has paved the way for 5G positioning services.

LampSite small cell / Huawei

For example, Huawei took the lead in completing the 5G indoor positioning verification in the Suzhou Metro in March this year through small base stations such as LampSite and MEC multi-access edge computing. By concealing the base station and deploying it in the ceiling, Huawei's 5G indoor positioning has achieved a positioning accuracy of 3 meters to 5 meters in 90% of subway booths and station halls.

This kind of precision is enough to cope with ordinary commercial scenarios, but it is not yet called high-precision positioning. In R17, which is scheduled to be launched in early 2022, a new work item LPHAP (low-power high-precision positioning) has been introduced. The goal of LPHAP is to further improve the positioning accuracy to 0.5 meters 90% or higher. At the same time, through the long-term sleep mode, the battery life of the positioning terminal can reach several months or even a year.

On September 28 this year, Beijing Zhilianan Technology announced the 5G LPHAP positioning chip MK8510, which supports the 5G frequency bands of N41, N77, N78, and N79, with an accuracy of 0.5 meters and 90%. Based on Zhilian's low-power control technology, the chip is positioned once every 6 seconds, and a 1000mAh battery can support 12 battery life. This LPHAP ecosystem built with chips, modules and terminal products, together with base stations and operators, is likely to become the main force for 5G positioning in the near future.

After operators have built 5G communication networks and positioning networks through base stations, they can provide 5G positioning services through the 5G location development platform. This not only includes the service of the operator itself, but third-party developers can also call open interfaces through the platform to quickly obtain the specific location of the terminal.

3GPP has also determined that the next generation of 5G evolution is 5G-Advanced, which is the so-called 5.5G, and officially started from R18. Under this standard, 5G will gain an ultra-large bandwidth of 800MHz or even above 1GHz, and advance 5G positioning to the centimeter level. At the same time, 5G-Advanced will introduce a minimalist air interface design to minimize air interface signaling power consumption, making the positioning module stand-by time to more than 2 years.

However, the freeze of R17 has not yet been completed, and R18 will have to wait until 2023. The millimeter wave 5G has not yet been fully rolled out. Both positioning accuracy and business model require follow-up exploration.

Complementary UWB and Bluetooth

When it comes to bandwidth, UWB technology known as ultra-bandwidth is naturally indispensable. The emergence of products such as AirTag has once again inspired UWB. UWB transmits data with extremely narrow pulses, so the bandwidth is basically above 500MHz. At present, UWB under ideal conditions can achieve decimeter-level accuracy, and other positioning technologies are beyond the reach. However, the frequency band of UWB is 6GHz to 9GHz, and the pulse penetration is not ideal, so the accuracy is higher when used in an unobstructed environment.

In addition to UWB, there is also Bluetooth technology that has impacted the positioning market starting from 5.0. Bluetooth can also achieve positioning functions through AoA and AoD technologies. However, due to the limitations of its own "hardware conditions", the accuracy is between the current 5G positioning and UWB positioning, and it is necessary to solve the interference problem in the complex signal environment. But its real advantage lies in its low power consumption and high popularity. Mobile terminals have basically popularized Bluetooth connections. Tags or terminals dedicated to positioning can also last for more than one year. Its characteristics are very similar to UWB. Good complement.

Bluetooth AoA Base Station / Four Phase Technology

Four Phase Technology has developed a set of integrated positioning system based on UWB and Bluetooth BLE AOA. According to different scenes, it is compatible with the positioning tags of these two signals at the same time. Four-phase technology's BLE AOA indoor positioning base station can achieve sub-meter positioning, while UWB can achieve positioning up to 10cm. In the large-scale coverage, UWB is responsible for full coverage, and AOA is responsible for the blind spot supplement of the occluded area.

Although UWB is currently the most accurate positioning technology, building a UWB positioning network requires positioning base stations and positioning tags. Although the number of the former is not high, the individual cost is still high. In contrast, the cost of Bluetooth positioning base stations is much lower, so this fusion scheme can further reduce costs.