From what I can interpret from the runtime requirements of sample region monitoring code of Apple, region monitoring is available on iPhone 4, iPad 2 Wifi + 3G or later. So I'm assuming that it's not available on iPad1 with 3G, or iPhone 3G/3GS.
Is this a correct interpretation? I cannot test this since I don't have all those devices and I couldn't find an official documentation about this.
PS: I know that I can check for it in the code by calling regionMonitoringAvailable method but I need this information to decide for the architecture of my app, so I need to know this upfront.
From what I have learned from working on region monitoring enabled devices is that you are correct.
Currently, region monitoring is only supported on the following devices (running iOS 5.x).
- iPhone 4
- iPhone 4S
- iPhone 5
- iPad 2, 3, and 4 (new iPad) 3G/4G
- iPad 3 and 4 (new iPad) Wifi
- (would love some feedback for region monitoring on iPod Touch models)
I was told at WWDC that with the advent of the location tiles in iOS 6, that region monitoring would be coming to ALL iOS 6 devices. However, my testing so far has only garnered me the Wifi enabled iPad 3. I haven't been able to test on the iPhone 3GS yet, but I'm not holding my breath. It may be possible that they will enable this in a later beta or at launch, but I'm not optimistic.
Hope this information helps.
来源：https://stackoverflow.com/questions/12243051/on-which-ios-devices-exactly-is-region-monitoring-supported