Understanding WP7 Push Notifications Battery Life
I know you all don’t troll the comments but Jimski and I have been discussing WP7 push notifications and how the always on connectivity of WP7 would work and how much of a hit it would take on battery life. If you’re getting constant updates to all of these social networks and online forms of media then you’re using a lot of data, you have an open connection and your battery is just getting chewed up. Well I doubt the Windows Phone Developer Blog was reading our exchange but they’ve been discussing push notifications and how they work. To begin with, it’s noted that the reason that there are push notifications is to avoid having too many running applications. It actually makes sense. If apps are running just to get cloud updates that’s pretty inefficient from a battery perspective when you just need that one service to continue in the background. And these notifications are not running on the app or continually polling the cloud (so notifications are ‘push’ notifications and not ‘pulled’ so they are more efficient). At 16:45 in this video they state: “With persistent connection scenarios…traditionally on the phone platform they are the most battery consuming so…we aggregate that into one single pipe and that single pipe is used by all applications.” They also explain that multiple notifications can be pushed at once so that you don’t need to open a connection for each notification since the server will aggregate notifications. While there may be a small delay in the notification, the battery life will be optimized. It’s also more efficient to have one pipe than multiple persistent connections each searching for updates. And the notification itself is a very small amount of data. If it’s a Facebook update for example, you still need to open the app to get the update so you get to choose if you want that to occur. Obviously if you had a series of social networking apps all collecting data in the background your battery would get torn a new one so this system works to balance the need to get updates with the end users expectations that they want a phone that can make it through a day. And there you have it – MS is thinking about these things.