I've been playing around with some Web 2.0 services (Widsets, Yahoo Go etc) on a Nokia E71, and one thing I've noticed is that they kill the battery, as they keep going online looking for new stuff to pull down. Given that the device has a huge 1500MAh battery, the fact it can be depleted in a day (and gets pretty warm to the touch too) indicates to me that we've got a problem here.
Anyone else experienced this? Obviously the simple answer is to turn off "push" and "background apps" but that sort of misses the point.
The other option is to have something clever in the network, like BlackBerry or the new notifications server bit in the Apple system, which wakes up the phone when necessary, without needing it to keep "polling" the network.
I've also heard stories that power issues can completely derail the "mobile presence" model - particularly if you have a "live" address book with hundreds of contacts.
I haven't had a chance to look in detail at yesterday's announcement by OMTP of their BONDI platform for Web 2.0 on phones (I have a meeting with them scheduled for next week), but hopefully there's something in there which could help solve the problem.
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Fully agree. Presence and/or other continual updates kill the battery. This is simply analogous to laptop running on battery all day with wifi connection vs. intermittent connectivity.
ReplyDeleteA wake up mechanism is a must here _or_ the nirvana of the perpetual battery. Place your bets on whichcomes first.
I have seen the same thing. In my experience it was intermittant 3g connections that drained the battery and not background apps.
ReplyDeleteTry the nokia energy profiler. It can log what power the phone is actually using.
I would like to see incoming e-mail addresses that convert to SMS. This seems to be common in the US (where the incoming messages get charged from your allowance).
SMS is the ideal notification as there are already lots of APIs for background apps to get notifications and the phone is listening to a control channel anyway.
It would be great if with a data bundle you also got a free e-mail address=>SMS on your device (even with quite tight limits on the ammount of notifications). It shouldn't cost much as it is only an internal SMS to the operator and would be very easy for developers to exploit.
Generally, the most efficient notification methods are silent SMS or maintaining an existing IP (preferably UDP) connection a little bit longer to get the updates through. If you do that, the even a large AB with thousands of presence enabled contacts has no significant impact on battery life. I have been using a Helio Ocean for more than a year that works this way and there is no power consumption difference between presence/network-enabled ABs and running it only in local mode. It makes a bigger difference if you are running in 1x or EV-DO mode.
ReplyDeleteParsing XML into and out of web services requests isnt going to do much for battery life either, or user experience. I hope their thinking includes things like the Hessian binary protocol for WS....
ReplyDeleteAnecdotally: yes! A number of the "cool" apps that you can now download and run will absolutely hose your battery. This is going to become a new skillset in client side software (something embedded guys have been used to for ages) : designing for power optimisation.
ReplyDelete