iPhone carrier update is small files that is used for updating the carrier-specific setting on iPhone gadget based on 2.0 software or newer than 2.0. This iPhone carrier update is able to be downloaded from iTunes 7.7 or later then install it into iPhone. Some updates that are included into iPhone carrier update are default APN update, special dialing code update through the following path Settings–>Phone–>(carrier) services, default setting for Weather, Maps, Stocks and many other items.
Based on apple website, here are some steps to check if updates are available for your iPhone:
- Make sure your comouter is internet connected and your iTunes is 7.7 or newer
- Connect your iPhone to your computer and then open iTunes
- You will see screen below if the updates are available for your iPhone
- By clicking on Update setting the following pop up windows will appear on your screen
- Then click on OK button
Based in what operating system you use iPhone carrier update file can be found. If your opearing system is Max OS X iphone carrier update file is in the following path /Users/[Username]/Library/iTunes/iPhone Carrier Support/. For Windows XP opearating system the file is in C:\Documents and Settings\[Username]\Application Data\Apple Computer\iTunes\iPhone Carrier Support and for Windows Vista opearating system iPhone carrier update is in C:\Documents and Settings\[username]\AppData\Roaming\Apple Computer\iTunes\iPhone Carrier Support\
source: http://support.apple.com/kb/HT1970
