A woman holding a smartphone, which infer the topic of using WiFi on smartphones

Building location-aware services with Android 9 Wi-Fi RTT

Juhani Lammi, 10/12/2018

Did you know that you can now pinpoint Android device location with 1-2 meter accuracy, even indoors? In this post, I’ll explain what Android 9 Wi-Fi RTT is all about and what kinds of cool services you could use it for.

Accurate positioning with Android 9 Wi-Fi RTT

Google’s Android Pie, released to the public in August 2018, introduced platform-level support for Wi-Fi RTT. This feature allows measuring distances between network access points, such as Wi-Fi routers, and peer Android devices.

What this means is that you can now build services utilizing indoor positioning, location-based voice control and location-based information. All you need is an RTT-enabled Wi-Fi router and a supported Android device – no additional hardware is needed. The one caveat is that the devices must implement the IEEE 802.11mc FTM standard for this feature to work, though.

If there are three or more RTT-enabled devices, the location of an individual device can be determined with 1-2 meter accuracy by using a multilateration algorithm.

The Android device does not even need to connect to the access point. The access point cannot determine the location of the device – only the requesting device can accurately determine its location. While it might take some time for device manufacturers to add Wi-Fi RTT support, it certainly opens a door for better indoor positioning.

Use cases for Wi-Fi aware devices

So, what is this technology good for? Here are a few ideas to stimulate your imagination.

Peer location detection

With a bunch of Wi-Fi aware devices, it would be possible to create a form of peer location detection. This would act like a location grid or a network of mobile devices. For example, a tourist group could form a peer network and the tour guide could use their mobile to check that no-one goes missing.

Indoor navigation

Large facilities, like shopping malls, can use Wi-Fi RTT to help shoppers navigate and find the stores they are looking for. Indoor positioning can be used for enterprise services, too – you can just as easily position workers in a factory or an office setting as well.

Providing location-based, contextual information

A store in a shopping mall could send a “Flash sale” notification to nearby devices: “Last 10 Donuts at half price!”. With the 1-2 meter accuracy, it would be possible to go even further and send messages from a specific location inside the store: “Products on aisle 5 are half price!” or for guidance: “This aisle contains toasters and coffee makers”.

Another use case would be an app that allows you to locate your friends or colleagues in a big event. There are lots of possibilities for gamification, too.

Voice control based on location

Voice control is a booming interaction method and smart homes with connected electronics are becoming more and more popular. In smart homes, accurate indoor positioning could enable voice commands such as “Turn off this light”.

How would you use accurate positioning? Or would you like us to tell you more? Get in touch!