How to get wifi band info. in Android?

I need to write a wifi scanner running on Android.开发者_StackOverflow社区 It works fine except that I could not find a way to get AccessPoint band (a/b/g/n) out of that ScanResult provided by Android wifi manager.

Is there any way to get this info? Or do I need to go to lower level? (maybe impossible).

Any help would be highly appreciated.