In our Live 5 for 2021 we raised micro-location as an area of technology where we expect to start seeing significant advances being made. UWB (Ultra Wideband) is just starting to get traction in consumer electronics and we believe that this will trigger innovation in micro-location technology.
So let’s back up a little, what is micro-location. Micro-location is room or building scale location technology. This is similar in function to GPS but on a smaller scale and with greater accuracy. Whereas GPS is great for figuring out where you are on a street in relation to a shop, once in the shop micro-location helps you figure out exactly where the item that you are looking for is. For comparison, GPS on a modern smartphone is accurate to around 5m whereas UWB is accurate to around 10cm.
BLE Use and Weaknesses
Bluetooth Low Energy (BLE) is currently used to provide micro-location services as it is supported widely on modern smartphones. One common use case is that of mapping services for large indoor areas such as shopping centres and airports. These use BLE beacons, and your phone uses these to determine how far away it is from a specific point in the location covered. By triangulating data from several beacons, your phone can determine its location within the environment. However, the robustness of BLE for micro-location is limited. BLE based solutions use signal strength to determine distance and have a resolution down to around 1m. Furthermore, this approach results in two weaknesses in the solution. Firstly, obstacles and reflective surfaces in an environment can result in the strength of the BLE signal received by the phone being weaker than would be expected for a given distance making it appear that a beacon is further away. Also, this approach is susceptible to relay attacks that can make it look like a device with credentials is closer than it is, meaning that BLE is not secure enough to use for proximity-based entry solutions.
Figure 2: BLE Relay Attack
The Benefits of Ultra Wideband (UWB)
Support for UWB is starting to come to premium smartphones. Apple started to include it with the introduction of the iPhone 11 and Samsung first included it in the Galaxy Note 20 Ultra. UWB has a couple of significant advantages over BLE that make it a more robust solution for micro-location. Firstly, the fundamentals of the radio technology used by UWB mean that signals more easily pass through obstructions and that reflections can be accounted for with relative ease. Secondly, UWB uses time-of-flight technology to determine distance. This approach uses the round-trip time of a signal out and back to a device to determine distance. The combination of technologies that underpin UWB enable it to have a resolution down to approx. 10cm.
The time-of-flight calculation used to determine proximity with UWB includes the time all the way to the actual device holding the credentials, and back. Consequently, an access control solution will calculate the distance to the device holding the credentials, not just the distance to the device emitting the signal. This approach to determining distance is what is enabling the Car Connectivity Consortium to add passive location-based car unlocking to their upcoming Digital Key Release 3.0 specification in a way that is secure.
Micro-Location 2.0 Solutions
Being more robust and having increased accuracy, UWB has the potential to extend existing micro-location use cases and create new ones. We’re already starting to see technology companies such as Sony and NTT DOCOMO, and BMW experimenting with it and starting to use it in production solutions. Here are a few examples of what we might expect to see from UWB:
- Improved contact tracing.
- On body tags to track posture and form for sporting applications.
- Mass transit systems could implement frictionless access control by tracking customers across the gate line.
- Large scale entertainment events could provide frictionless VIP access to events.
- Automotive companies are already working on enabling frictionless car access.
- Payments could be made without you ever having to take your payment credential (card / phone) out of your pocket.
- Proximity based data sharing could be enabled to allow emergency services / first responders with appropriate credentials to access medical data from a person’s phone when in their immediate proximity e.g. when treating them in a medical emergency.
These are just a few of the possibilities, and I am sure others will emerge as the technology starts to gain traction.
We view this very much as a technology that is starting to emerge, so the solutions described here are still, in many cases, some way off. Few phones currently support UWB and in some that do, such as the iPhone, the APIs available are currently limited. However, the potential opened up by the ability to determine a person’s position in space accurately, with confidence and in a robust way is likely to create innovate solutions that change how we interact with services in the physical world.