How to Force the iPhone to use Only 3G Network
One of the features of the iPhone is definitely more to appreciate the mobility and the various applications based on Internet.Unfortunately it often happens to find himself connected to EDGE / GPRS rather than 3G, despite the availability of the network for which we provide below a brief guide that lets you stay connected always and exclusively on the 3G network. It should be noted that 3G is not available in any place that might happen to be virtually no possibility of a data connection. Perform these steps only if your area is supported by 3G.
Please note that this will not improve your reception, it will just make the iPhone work in UMTS only mode and will disable the phones ability to fall back to EDGE. Your iPhone will NOT fall back to GPRS, so make sure you are in a area with strong 3g signal, otherwise you will not receive calls or use internet when you have only 1 bar of 3g signal. Because you say goodbye to 2G already.
To make 3G service by default in your iPhone you need to access the iPhone file system via SSH and change a string. If you aren’t aware with SSH things then check our previous article How to Access iPhone File System via SSH on Windows Mac
1. Navigate to directory "var / preferences"
2. Search and Copy the file CSID and save it on your computer, then open it with any text editor like notepad.
3. Look for the string: "GsmRegistrationModel: fRatSelection = 0 × 1"
4. Replace it with this: "GsmRegistrationModel: fRatSelection = 0 × 2"
The following values apply: 0×0(EDGE ONLY), 0×1(EDGE+3G), 0×2(3G ONLY).
5. Save the new file and upload it again via SSH in the same location before.
6. Restart your iPhone and enjoy the fast 3G connection
Note: To return to use both EDGE and 3G simply perform the same step and put the final code "0 × 1", if you set "0 × 0" the connection will only edge.
Warning : If you try this you are doing it at your own risk