We all love it when technology makes life easier for us. But what if you could walk up to your front door and have it automatically unlock and open for you? Or go through a subway turnstile hands-free without using a token or ticket? How about being in a mall, airport, or museum and being able to see exactly where you are on a map on your phone?
To make accurate indoor navigation a reality, FiRa™ Consortium is currently developing ultra-wideband (UWB) untracked navigation, a significant new technology that goes beyond the limits of existing indoor navigation techniques in accuracy, scalability, and privacy. Other potential applications include the ability to navigate in an underground garage, supplementing guide dogs for the visually impaired, and even finding a lost child in a crowded area.
How Other Technologies Work
Up till now, indoor navigation relied on UWB Two-Way Ranging, which accurately measures the Time-of-Flight (ToF) between UWB devices. This technology needs at least two ToF values with two different UWB anchors with known positions for two-dimensional positioning. To estimate a person’s location, there will be messages between a user’s device, often a smartphone, and a set of established anchors. However, when the number of users increases the number of messages transmitted increases. This can lead to message collisions, limiting the number of users that can simultaneously leverage the indoor navigation services with a stable performance. Technologies based on Bluetooth® and Wi-Fi have similar limitations in scalability.
Uplink Time Difference of Arrival (UL-TDoA) can help solve these scalability issues since a user’s device periodically only sends one uplink message for the UL-TDoA to estimate a user’s location. A drawback is that this technology needs anchors that are synchronized and connected to a centralized server capable of real-time location service – which is much more expensive to utilize.
How Untracked Indoor Navigation Works
FiRa’s execution of UWB-enabled untracked indoor navigation uses the downlink Time Difference of Arrival technique, DL-TDoA, also known as reverse TDoA, as a technology base. With this technology, no message is transmitted by user devices. Instead, a user’s device overhears the messages sent by UWB anchors to estimate their location.
Since a small number of messages is enough to compute a user’s location, regardless of the number of devices being used in an area, the technology is scalable. Also, UWB anchors simply need to be installed at planned locations and don’t need to be connected or synchronized between them using a wired network. This makes installation simple and cost-effective. Plus, UWB untracked indoor navigation enables centimeter-level positioning accuracy. This is a marked improvement to previous technologies.
UWB untracked indoor navigation is not only more affordable, scalable, and accurate, it also offers a higher level of security. In an era where personal information such as location is considered of utmost importance, having a location technology that is – as the name suggests – untracked is a significant improvement. With this technology, the location of the user device is determined by the user device itself. This stops a user’s location information from being exposed or the user from being tracked. It also prevents relay attacks, protecting the user’s privacy from being compromised.
The Future of UWB Untracked Indoor Navigation
Future use cases are virtually endless. FiRa is helping to define the potential of UWB untracked indoor navigation to include smart cities, buildings, industries, retail, and homes. Since most of the future use cases for untracked indoor navigation include a user’s smartphone versus a swipe card or key fob, the navigation technology to enable those use cases needs to be simpler and easier to implement. From this point of view, this simple but powerful indoor navigation technique will allow indoor venues to offer greatly enhanced location-based services to visitors and employees by having them rely on devices that they already have in their hands.