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[App Idea] GSM/WCDMA Switcher

Hey guys,
As the radio stack is the second cause of battery draining after the display, I was thinking about a way to save battery life by reducing the impact of the 3G connection. Most of the energy saving apps on the market are only disconnecting the phone from the APN, but this isn't a great solution as each app could be set to update at different times and thus being unable to download data even if the user sets some exceptions. So I thought that an application which operates in the following way could be great to save power:
- The phone uses the 3G network while the screen is on;
- It switches to 2G when phone is in standby mode;
- It disconnects the APN data connection while the phone is using a WiFi Network;
Obviously to avoid possible issues during the switch between 2G and 3G the following rules are applied:
- If there's an incoming call or a phone call is being performed, there won't be any radio switch until the phone call is ended;
- If there's an incoming SMS/MMS, there won't be any radio switch until the text message is fully received.
Unfortunately as I'm not a Java developer I can't code anything like this. But let me know what you guys think about my idea and if it's technically feasible... Maybe some developer could be interested into further exploring my thoughts and will try to create such an app
Cheers

I'm not a developer but I think it sounds like a great idea. I go into settings and switch it to 2g when I'm in spotty areas outside of town. I have to work a bit to keep my N1 battery alive all day...

Hello I'm new here.
I don't know if your suggested profiles are the best case scenarios. You would need to calculate your data throughput, not just the radio power.
If you need to send 100 packets, your radio would be on the longest for edge > 3g > wifi. So, even though wifi uses the most power, it would be for a much shorter duration.
A profile for "place calls only" would work somewhat like airplane mode, but still keep track of towers. Your phone just wouldn't register on the network unless you wanted to place a call. You would miss your incoming calls, have no data connection, or sms. But, you could have it check at an interval for voicemail or sms. This would be most useful for "ringer off" situations like class or meeting.

Afaik Android is always connected to the APN even if the phone is not downloading anything, consuming a lot of battery power. On other platforms, i.e. Windows Mobile, the connection can be terminated by user and re-established when an app needs that.
The amount of data downloaded by widgets, Google mobile applications or apps which operates in background like eBuddy or Facebook should be quite low, so downloading the required data by using GSM or WCDMA while the phone is in standby would be pretty much the same. The only difference is that downloading stuff using GSM/EDGE should take much less energy power.
So that's why I thought about the app I described before: the phone can save a lot of energy power while in standby and be back to its full horsepower when there is any kind of user intervention. Pretty much the same thing that the system already does for CPU usage. It scales to the less consuming protocol (or, in the case of CPU, frequency and voltage) to save power

I know on the google api it isn't possible to do this, but I don't think that isn't the problem.
At the moment you have 3 options. GSM only, WCDMA only and GSM/WCDMA. Whenever you switch between the 3 of them, the phone will lose signal for 10 seconds before it can find the best network. So the switcher here is not the best as you will lose connection, and what if you are downloading something at the same time...
What you need is when the phone is on GSM/WCDMA that it knows the best network to pick from depending on the phones lifecycle. GSM/WCDMA loses battery power because it always tries to find the best network to connect to, so for example if you are on GSM it will constantly try to find a 3G network etc (as far as I understand it).
What we need is the ability for the phone to stay on GSM when the phone is idle and then when the phone is woken up to automatically start to search for a WCDMA network and then gracefully switch over like it does now. For this I have no idea if it is possible as I don't know how the scanning of the network works. If it is possible then that would be wicked. But this is what we need.

my preference would be if the phone would stay on 3g as long as any possible even if there would be a more reliable 2g connection and only switch to 2g if there really is no way to connect to 3g. turn of apn if the screen us turned of for longer then 1 or 2 minutes and only check every 15 minutes or so.
most of the time I'm on 3g only mode . since I live in a city I got good coverage almost all over the city. only problem is that when there is no 3g available also my phone is unreachable. I don't really miss data connectivity when there is no 3g since 2g is so slow that I rather have no internet at all but not being sale to be called or texted is a major disadvantage...
Sent from my Nexus One using XDA App

Disable 3G/ Use EDGE Only

For all the people that need their battery for a day or more I wanted to add the instructions on how to disable 3G.
Go into the dialer and type in *#*#197328640#*#*
Select "Debug Screen" on the menu
then hit "Phone Control"
then "UE State Control"
"Change RAT to GSM" will turn off 3G access and will leave your DATA on 2G.
This will save lots of battery especially for those who have low 3G signals.
Please note that rebooting the phone or even turning on "Airplane mode" will reverse these changes.
This means you will have to change the settings again (this is also the fastest way to cancel the changes and go back to 3G).

Thanks a ton for this. I'm sure it was in another thread, but I always saw mixed reports and hadn't tried it myself.
I have a 3-4 bar EDGE signal in my office, but only a 0-3 3G signal, so this will be a lifesaver.
However, as soon as there's a ROM that adds the force 2G option that should be there back into settings (and removes any other locks AT&T put in the software), I'll probably go that direction just because it is a pretty clunky way to do something that should be an option as is.

I have something to add to this. If you use a reboot or airplane mode to turn 3G back on, the next time you go to turn 3G off, you may need to re-enable 3G (WCDMA) before changing back to GSM. Apparently, the setting didn't get changed in the debug menu even though I got switched to 3G, so I had to put it back on 3G first.

Is this still the only way to disable 3G but leave 2G enabled on the Captivate? The apps in the Market are still all or nothing (3G or no data connection at all).
Thanks!

3G, 2G disabling?
Is there a way to disable the 3G/2G altogether but still use wireless?

You can always put it in airplane mode and then turn WiFi on if you don't want to use the AT&T network at all.

Will the Droid Charge automatically switch from WiFi to 3g?

I have the Wifi enabled on my Droid Charge so when I'm home it will use the Wifi. But when using the Wifi the 'mobile data' icon is still highlighted in the pull down tasks..
now is it trying to use BOTH the wifi AND the mobile data at the same time? I want to use ONLY wifi at home to help conserve battery usage.
then when I leave my house will it automatically turn wifi OFF and use only mobile data?
trying to keep the battery usuage as efficient as possible.

In theory thats how it's supposed to work.

hahahha in theory.. but does it actually do it?
and another thing.. in the Mobile Networks Settings.. under 'System Selection'.. you can choose either LTE Automatic or CDMA Mode... being I am ONLY in a 3g area and do NOT have 4g LTE in my area yet.. should I choose the setting for 'CDMA Mode' Will that save the battery? or does the phone try to switch from 4g to 3g...

Yes, that is how it works. If wifi is on, the phone will use wifi by default, regardless of what it is connected to for mobile data (4g, 3g, 1x). Check out http://myresolver.info from your browser to see your ip and dns server you're using.

2G vs 3G battery usage

Ok I've got a few questions about the different network types and battery usage.
As far as I know there are 4 different possible scenarios:
3G mode active
3G mode active and connected to mobile data (3G/H showing in notification bar)
2G mode active
2G mode active and connected to mobile data (E or G showing in notification bar)
Currently I have settings default with "Use only 2G networks" unchecked, and "data enabled" unchecked. I have tasker made to automatically turn mobile data on whenever I open any app that may require it, and then turn it off after the app closes, or I can switch it on from the status bar power control.
This is because I assumed having it constantly activated would consume more power. Is this true? does it consume more power having data enabled even when no traffic is going through? If this wasn't the case, I might as well leave it enabled. However with my current system I could still be saving power because if I leave data on, traffic WOULD periodically be used for automatic sync and apps randomly using network and stuff.
The other thing I was wondering about is if there was any major difference in power consumption between 2G and 3G network modes with no mobile data connected. if 2G uses much less power, I could have it set on 2G by default then use tasker to switch to 3G and activate mobile data when opening any internet requiring app. Are there any other advantages of having 3G active over 2G other than mobile data transfer speeds?
Thanks for any help!

Imho your settings are good. Mobile network is one of the battery killlers, so not using (or better using it when you really it), is very good. You are right, 3g has a higher speed on mobile network. Whereas the 2g-network has a much better network coverage. And the permament switch between 2g and 3g drains the battery very fast, too (happens e.g. when you travel).
To sum it up: Use 2g and mobile network off. If you need to use mobile network, turn 3g and mobile network on. Are you done, turn them off again and switch back to 2g.

When you say mobile network, do you mean when an active data connection is enabled?
Because just by the name 'Mobile network", you can be connected to a mobile network for calling and texting etc. without being connected to mobile internet/data.
Is there a difference in call quality between 3G and 2G networks?
Also when toggling between forced 2G only and 3G there seems to be an inactivity period where the reception icon at the top shows like 'disconnected' like it cuts all network communications, then shortly connects again to the specified network type. This delay might be annoying when trying to get internet fast on apps that need it... might not be worth the power saving, if it is only minimal power saving

battery
for the best battery duration, use GSM ONLY!

Prevent 3G data connection

Hi All,
How do I make it so that my phone will not try and connect to the internet via 3G (the signal icon on the status bar has 3G written on it). Whenever my phone switches to 3G, internet doesnt work. this has been a problem for me here in Aus on multiple phones. While the icon says H, internet works awesome but the second it switches to 3G internet stops working until it switches back to H. It wouldnt be too bad, if it wasnt for the fact that the bloody thing switches back and forth every 5 seconds if Im in a good reception area, which is almost all the time.

Are you rooted/custom ROM? It sounds like it could be a poorly performing radio. Search for the radio/ril thread. You might find some answers there. You can switch your phone to 2G or 3G networks only, but the 3G option also includes H. So even if you left out the 2G you'd still suffer the same issues.