I have done trilateration tests with other beacons, and the running average that is given by CoreLocation can take maybe 10 seconds to adapt to a new location. So I tried using instantaneous RSSI, but that jumps around in strength quite a bit, and only can be read once per second (with the beacons I have). If I just average the last few readings it can be more useful than the running average method CoreLocation uses, but still requires a few seconds of checking. And, with three beacons all doing their random RSSI twitchiness you’re lucky if the location is anywhere near correct.
Are your beacons special in any way? Like, how many times per second can they broadcast, and will the signal strength be more predictable than my cheaper beacons?
Another way to ask what I want to know: if you are 20 feet away and getting a steady 20 feet distance reading, and you teleport instantly to 2 feet away, how long would it take until you’re getting a steady 2 feet distance reading?
While we invest a lot in the antenna design and extensive testing, which probably already makes things better than cheaper beacons, Bluetooth is inherently a difficult technology to work with when it comes to positioning. So we mostly tackle the problem on the software side. Core Location is a simple API from Apple to allow basic beacon detection, but it was never meant to be used for positioning. Our Indoor Location on the other hand … well, positioning is its core feature, and we apply a ton of complex math and algorithms to make it work much, much better than CL. But these are just words, I encourage you to give it a try (:
As for your other questions:
Like, how many times per second can they broadcast, and will the signal strength be more predictable than my cheaper beacons?
Our Indoor Location requires the beacons to be set to at least 200 ms broadcasting interval—and benefits from lower values = better accuracy, but this naturally comes at the expense of the battery life. Broadcasting power is required to be set to the maximum.
Another way to ask what I want to know: if you are 20 feet away and getting a steady 20 feet distance reading, and you teleport instantly to 2 feet away, how long would it take until you’re getting a steady 2 feet distance reading?
If you did indeed teleport, I’m pretty sure our Indoor Location would end up completely puzzled (: Our mathematical models operate under the assumption of real-world conditions. If you walk 20 feet, changes in the position should be almost real-time. If you walk fast or run 20 feet, the lag might be a few seconds. But then again, it’s very hard to give any specific numbers, as a lot depends on the actual environment, the number of beacons used, the device (iPhone models differ slightly when it comes to performance of their Bluetooth radio, available sensors, quality of said sensors), etc.