how can i leave my iphone or ipad on the 2G mode for receiving notifications to save battery, is there are any software can help me in that issue ?
the question in other way: how can i switch between 2G/3G mode in iOS 6 ?
Whether you have that ability is determined by the carrier file on your phone...in other words, your carrier determines this, not the iOS on your phone.
If not an available option for your carrier with iOS 6 on the devices, you can't.
For example, this used to be an available option with the iPhone and AT&T, but not any longer since AT&T started rolling out their LTE network.
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