Back in the early days of the iPhone 3G when signal strength was a big issue, the more technical forums published the code which when entered displays field diagnostic information about the GSM signal received by the phone. Of bigger interest for my use is the display of the signal strength in decibels rather than bars. It has been a well documented problem that the bars do not provide a good view of the signal's strengths. I have had failed calls when I had 4 bars, especially in my home where I seem to be at the edge (no pun intended with Edge data) of 3G with decent 2G coverage, however the phone is always trying for 3G. My assumption is that calls fails when the phone is trying to move from 3G to 2G or vice versa.
The signal bars at the top left hand corner displays relative strength up to 5 bars, however I have found this display to be less than accurate.
Keying *3001#12345#* then tapping call in the phone's keypad yields this display which contains mostly diagnostic information, however it replaces the bars in the upper left hand corner with an accurate signal strength's value. The lower the decibel value, the better. Tapping the home button with take you out of the diagnostic mode.
How do you get the signal bars back in the upper left hand corner? the home button didnt put it back
Posted by: Curbi | December 08, 2008 at 03:54 PM
clicking the hardware home button at the bottom of the iPhone returns you to the bars.
Posted by: Stephen Skarlatos | December 08, 2008 at 05:57 PM
I Just wanted to add that Gotreception.com (http://www.gotreception.com) is a great resource for finding out where reception problems are most likely to occur.
Posted by: dave88 | December 15, 2008 at 12:29 PM