I’ve placed two phones on this diagram at the transition between the weak and the strong. The green is the strongest signal, near the AP and the red is the weakest, measured toward the edges. Figure 1, with the access point in the center, shows a heat map of the signal strength around a Wi-Fi access point (AP).įigure 3. Basically, we can calculate distance as a function of signal strength. At this time, we use Wi-Fi received signal strength indication (RSSI).
Wi-Fi RTT ranging and indoor position estimation is based on making measurements of the time of flight of RF signals, and can be used to estimate your indoor position to an accuracy of one to two meters.īefore we get into the details of Wi-Fi RTT, we want to tell you how we currently calculate an indoor location.
#HOW ACCURATE IS FIND MY DEVICE ANDROID ANDROID#
But the important thing is that we are sure that you will have many more ideas than we have, and that’s the beauty of the open Android ecosystem. What you really want is the traffic speed in the lane that you’re in, so that you could ask, how much faster would it be if I took the carpool lane instead? There are, of course, many other use cases and we’ll mention a few.
Even for the most loved outdoor applications such as map directions and finding alternate routes in traffic, we could benefit from higher accuracy than we have now.įor example, when you came here this morning in a car, you probably had your arrival time estimated using the average speed of the traffic. You might wonder, why do I need better location accuracy anyway? Let’s look at two instances where existing apps could use much better location accuracy.įor indoor routing or navigation of the kind that you’re used to in your cars, you need much better accuracy than you have outdoors: you need one-meter accuracy, because indoor features like cubes or aisles are only a few meters wide. We want to work with you to accelerate development and bring the present closer to the future. If you want to wait a year or two, this will find its way into the worldwide ecosystem and the Android fused location provider API, but we want to give you a chance for a one- to two-year lead by taking accurate measurements and turning them into accurate location. The key technologies are Wi-Fi RTT, GPS dual-frequency and carrier phase measurements. We’ll show you how one-meter measurement accuracy can be made available in smartphones. But with raw GNSS measurements from the phones, this can now improve, and with changes in satellite and receiver hardware, the improvements can be dramatic.Įveryone’s familiar with the blue dot, but to get the blue dot you need a location provider, and to get location you need measurements - specifically, range measurements from Wi-Fi access points or from GPS satellites. If you’re outside and can see the open sky, the GPS accuracy from your phone is about five meters, and that’s been constant for a while. Meanwhile, what about GPS? In terms of GPS accuracy in the open sky, there has not been much change in the last few years. There continues to be improvement, and you’ll see indoor accuracy of better than 10 meters, but round-trip time (RTT) is the technology that will take us to the one-meter level. With each release of the fused location provider, we have had steady improvement of the Android algorithms and machine learning for Wi-Fi locations. Where are we today with indoor location accuracy? If you’ve noticed that your phone seems to be more accurate when you’re inside shopping malls and office blocks than it was a few years ago, you’re not imagining it. We will highlight where you must get user permissions and we’ll close with some guidelines for making great location apps. The more people who use location, the more careful we and you have to be.
We also want to highlight the need to protect and respect the user. It’s a great time for location applications because technology hardware standards and Android application programming interfaces (APIs) are all evolving simultaneously to enable an improved location accuracy that has not previously been possible when using smartphones.Įventually, this means high accuracy for everyone, but we want to take you under the hood of location because we want to give you the opportunity to get a head start on the future. Image: GPS World outdoor, Andriy Solovyov/ indoor, Rade Kovac/