iOS 5.1 Beta 3 (Build 9B5141a) this does not bring any significant change compared to its predecessor, but there is one feature that back into this beta OS that is toggle 3G, this feature provides an easy to use mode change from 3G to 2G/EDGE.
Toggle is initially abolished when Apple released the iOS 5.o, but Apple seems to change his mind and put it back in this latest beta release. To toggle this setting can be found in the 'Settings> Network' good for the software pre iOS 5 or 3.1 Beta 3. When you turn off 3G data, you will use 2G/EDGE network of mobile operator you use. Although the speed at which data will be slower indeed, the use of batteries will be much more sparing in this mode.
Apple also provides enhanced API (application programming interface) to assist developers in determining the specific application files that do not need to be backed up by the system. In addition, Apple also asked the developers to test features of iOS 5.1 airplay with their application.
