Fast Dormancy and Battery — September 5, 2011

Fast Dormancy and Battery

Recently while nosing in with my device I stumbled upon (Not the website ,I hate that stuff) a feature known as fast dormancy .More about it .

What is Fast Dormancy? In simple terms its a device feature that enables mobile devices to notify the cellular base stations when the radio resource allocated to the device is no longer in use, so that the radio resource could be immediately released other than waiting for a timeout event. For instance lets say you are browsing a webpage using your cellular data plan. You stop at a certain webpage (for example to read this article) the connection is maintained and the device will be registered on the network even if data isn’t received or transmitted (always on) and will remain like that until a timeout event is invoked (as per the network rules as to how much time to wait before connection is terminated due to idle timeout). During this time the device’s battery will be drained needlessly in addition to increased congestion on the cellular network due to numerous idle connections. From a device perspective radio power consumes battery so employing fast dormancy should save battery power and increase its life. This also has an advantage to networks as it reduces congestion. But This doesn’t come without a major disadvantage to the very same cellular networks and operators. The making and breaking of the connections increases the signaling traffic and wastes network resources. The workaround to this was done by Nokia Siemens in collaboration with Qualcomm to employ NCFD or Network Control Fast Dormancy in which the device is put on a battery saving idle state while maintaining its network identity without the need to establish a new connection and request a new identity for the device on the network.

What does the above gobbledook mean ?

simple .If your network supports it ,you will save battery and increase it’s life .

If not ,it may hang your phone .esp . people having black screen hangover .Or it may consume more battery .

Calling your customer care representive and asking them “Hey does ABC have Fast dormancy” wont help .I have serious doubts they know it .

If you disable dormancy and your network supports it ,your download speed may slash .(especially those with 3G HSDPA )

It’s more of trial and error .It may or may not increase battery life .

You need a week of tests on both versions to give conclusive results (Mine would be super inconclusive so)

Androids have default Fast Dormancy switched on

I have disabled it today as a whim .

Switching Fast Dormancy On and Off will consume battery .

one hour is not a conclusive test span .

It may may SERIOUSLY affect the network data speed .

It doesn’t affect affect WIFI. 

*#9900# is the code to access the system dump menu .The below pic shows mine is disabled .

Advanced Battery Calibration

After freshly caliberating battery or installing a custom  ROM ,it is advisable to go through a full charge -discharge cycle atleast 5 times and then do whatever you want .

That way the battery will be properly calibrated .Though I wont advise you to do it every time as said in my previous post.