The growing importance of localization in a mobile world (Reader Forum)

In a mobile world, we now realize that one of the indispensable elements of most devices is positioning. Some apps are already common: navigating our phones and cars, finding where we parked the car, or keeping track of our kids. Location services for the IoT in general, for drones, logistics tracking, positioning for static devices in agriculture and urban automation, are growing even faster.

The GNSS market is expected to grow at a CAGR of 17% through 2025, according to GlobeNewsWire. Markets and markets expect the IoT location market to grow at a CAGR of nearly 38% by the end of 2022. This is a great opportunity, but the challenge is that it There is no perfect solution to all positioning needs. The best solution to meet a specific need often requires a mix of technologies.

COVID Tracking

Proximity monitoring for pandemic management has become commonplace around the world in the wake of COVID. Bluetooth, primarily Bluetooth Low Energy (BLE), is the de facto choice for this, offering excellent matching with reasonable accuracy combined with very low power consumption, and importantly, it is already widely available on mobile phones. Considering the alternatives, UWB would actually provide a more accurate measurement, but its rollout to mobile phones is just beginning and far from universal. GNSS, although widely available on cell phones, is far too power-hungry to be left running for this application. This makes choosing Bluetooth a study in engineering pragmatism.

However, as in many applications, the whole solution is more than just proximity sensing; you also need periodic cloud communication, via Wi-Fi and/or cellular broadband, facilities again readily available on phones. Of course, Covid itself is not just infecting those carrying cellphones, but the low power of BLE again allows for the deployment of low-power wearable tags, such as those deployed in Singapore’s TraceTogether system which incorporates Ambiq’s MCU Apollo3 Blue.

Global Logistics Tracking

In times of tight supply chains, it becomes even more important to know where your order is and how long you will have to wait to get it. It’s a location problem all over the world, from Shenzhen, across the Pacific to Long Beach, to a warehouse, to your home or factory. Only GNSS can cover this range.

But asset trackers have to be very low-powered, continuing to work for weeks-long rides. For true package-level (rather than pallet-level) tracking, the asset tracking tag must be very expensive. Traditional GNSS does not quite meet this objective. Putting the pragmatic hat on again, we can compromise on “snapshot” positioning rather than continuous tracking, with position snapshots being calculated on a slower periodic basis. In addition to less power, this also allows us to use software GNSS on shared hardware resources, which significantly reduces costs.

Again, GNSS itself is not a complete solution. A cellular data link is essential to communicate position with extended roaming, for example, NB-IoT or Cat-M. Such an auxiliary link also enables faster downloading of satellite orbital data, reducing on-device GNSS processing time, a technique known as assisted GNSS. Some treatments can even be offloaded to the cloud via this link. When cargo arrives in a warehouse or inside a tower, a different solution is needed. GNSS doesn’t work inside, but there are almost certainly Wi-Fi access points (APs) around the building. Time-of-flight measurement to multiple access points provides sufficient accuracy to locate a package or pallet within 10 meters.

Bluetooth telemetry, with AoA/AoD, can also be used, especially in a factory environment with dedicated infrastructure, but for ultimate factory accuracy UWB is the winner, with its centimeter accuracy and multi signal robustness. -paths. These techniques can also be supplemented with integrated motion sensors (an inertial measurement unit or IMU) to orchestrate position calculations in a power-efficient manner and to provide a level of dead reckoning.

Other localization goals

Navigation tracking and real-time location systems (RTLS) are massive market segments on their own, but there are many other consumer applications that can derive value from location information. “Find-my-stuff” apps like Apple’s AirTag are good examples.

High-end convenience applications like keyless access to a car or hotel room are also growing in popularity. Today, this is based on Bluetooth but is vulnerable to man-in-the-middle/relay attacks. UWB, however, provides much more accurate measurements of key fob distance and provides additional security due to its physical layer (PHY) nature. By coupling UWB with BLE, as popularized by the FiRa Consortium and the Car Connectivity Consortium (CCC), you can enjoy both the low power benefits of BLE with the added security and accuracy of UWB.

The spatial awareness enabled by UWB’s precise scope also creates new opportunities for users to interact with their devices, like point-to-check. Point your phone at an object you want to control (TV, thermostat, microwave) and the phone offers context-appropriate menu options.

Summary

As you can see, one size does not fit all in location services. It’s a good balance between power consumption, cost and accuracy. The most compelling solutions use multiple techniques to determine position and communicate that position, even in mass consumer products. Leaders like Apple are already integrating GPS, cellular, Wi-Fi, Bluetooth and UWB even into their smartwatches.

Melvin B. Baillie