I found an article that seems to be what you're looking for. It will help you troubleshoot your cellular connection on your iPhone.
iPhone: Troubleshooting a cellular data connection
Here are the steps within the article:
Follow the instructions below for assistance with troubleshooting cellular data issues on your iPhone. After performing each step, please test to see if the issue is resolved.
- Toggle cellular data off and then on again on the iPhone: Tap Settings > General > Cellular.
- Restart your iPhone.
- Check for a carrier settings update.
- Update your iPhone.
- Remove the SIM Card and reinsert it. Allow the iPhone to reaquire the network.
- If your SIM card has SIM PIN enabled, try toggling it off: Tap Settings > Phone > SIM PIN.
- Try another location. If a different location works, but the original location still does not, contact your carrier to report the issue.
- Reset network settings: Tap Settings > General > Reset > Reset Network Settings.
- Restore the iPhone as new.
- Contact your carrier to verify that the iPhone is properly set up on the account with the appropriate, current data plan. If you are traveling internationally, you may need to turn data roaming on: Tap Settings > General > Cellular. Check with your carrier first to understand the cost of international data roaming. Also, see this article.
Note: If your carrier does not appear in this list, verify with your carrier that you are using the correct cellular data settings.
Hope this helps,
thanks for reply i have done al of this but still same issue when i goes to carrier they said to me that it is not our side proble
and when i goes to the apple authorised store they said it is ok iphone has not an issue but can you tell me one procedure that resulted it is network issue or iphone issue
I am also based from ahmedabad, gujarat. i am also facing signifcant problem with the network on the iphone 4. the phone has already been replaced, bu the same problem continues to subsist. this problem is not faced while using the iphone 3gs, blackberry and nokia handsets in the same locations where the iphone 4 is showing network problems. hence, the problems, to my mind seems to be with the build of the iphone 4.
may I request the apple authorities to find some solution to this problem.
My iphone 5 kept dropping calls and other issues and today, I found out at an Apple store that it was an issue with my phone. I also went and got the latest series of SIM card from my carrier. I hope I don't have the issues I had before. Take it to the Apple store and have them retest and look at the diagnostics. Good luck.