What is pair tracking good for?
If you do not sleep alone in your bed, tossing and turning of your partner may affect your activity measurement (hence sleep phases detection, hence smart alarm and other sleep-phase dependent features), because a single mobile phone is not able to distinguish between the two moving bodies. Pair tracking uses two cooperating phones (your and your partner’s) simultaneously to filter out the partner’s activity and obtain clean separate activity records.
Check our blog post for the full story.
How does pair tracking work?
Both you and your partner need to have Sleep As Android installed on your phones. Then you need to pair the phones, i.e. tell them that they should cooperate during sleep tracking. Go to Settings/Sleep Tracking, to the new “Pair tracking” section. Enable Pair tracking, and then tap at “Find partner” simultaneously on the both phones.
The two phones will attempt to connect to each other and form a pair. When it succeeds, the screen will look something like this.
If pairing does not succeed the first time, please be patient and try it one or two times more. It will eventually pass. Now the two phones know about each other. The grey cryptic string at the bottom is their shared secret, which is unique for each pair, and by which the two phones recognize each other.
When you go to bed, you start sleep tracking as usually, and so does your partner. There is no need to start the tracking simultaneously, just use the app as you used to. During sleep tracking, the phones attempt to connect to each other and exchange their activity data, so that each phone also has a full record of the partner’s activity. From the two datasets, we are able to discount the partner’s activity and extract a clean actigraph for each sleeper. For the time periods when the partner phone is not reachable, tracking works just like it used to, calculating everything just from its local recording.
Sleep records where pair tracking was used for at least a part of the night are tagged with a new “pair” tag and an icon symbolizing a pair.
If you sleep alone temporarily, you may disable pair tracking, and it may save a bit of energy. Although, the difference is not very big, the impact of pair tracking on battery consumption is usually negligible.