Existing users, 
iPhone 3G Signal Strength Problems Persist in OS 2.1
Posted 22 September 2008 @ 6am in Troubleshooting
Users continue to report poor 3G signal strength under iPhone OS 2.1. To be clear, iPhone OS 2.1 does not purport to actually boost signal strength. Instead, it provides “more accurate” signal strength display, which, in most cases, means more bar bars, but not necessarily better reception or ability to make/receive cals.
Two sample reports from this Apple Discussion thread:
- “the point is that the 3G did go from zero to all the bars but still dropping the calls!
- “I just bought my iphone yesterday and asoon as i got home the reception was terribal so i updated it to 2.1 and instead of getting no bars i get 1 to 3 bars but it goes off and on and turns 3g off and goes to edge.”
The most reliable indicator of actual signal strength is the iPhones dB meter, which can be accessed in field test mode. Dial *3001#12345#* then press “Call.” A dB reading below 50 generally indicates good strength.
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13 Comments
Posted by jzdziarski
22 September 2008 @ 6am
Apparently dropping your iPhone on a tile floor improves your reception. At least it did for me. Use at your own risk.
Posted by jameskatt
22 September 2008 @ 7am
The problem is AT&T’s network.
AT&T has been building up the network, but it is still too infantile to handle all the data use from iPhone users.
So sue them.
Posted by simplymac.de
22 September 2008 @ 7am
Wrong code: field test mode is invoked by *3001#12345#* (leading and trailing star are missing).
Posted by michoffm1
22 September 2008 @ 9am
Dial 3001#12345# then press “Call.” obviously only works on AT&T ;-(
Posted by mopcodes
22 September 2008 @ 9am
The CORRECT code to enter into your iPhone is:
*3001#12345#*
Star 3 0 0 1 # 1 2 3 4 5 # Star
no spaces (only for read ability here)
Posted by Ken Weeks
22 September 2008 @ 10am
I cannot get either of these codes to work. Is this to be done on the keypad, or do you need to do something else to get into the Field Test Mode?
Posted by xcecllpress
22 September 2008 @ 3pm
What am I looking at once in field test mode? What is the navigation process?
Posted by michoffm1
23 September 2008 @ 1am
enter via the phone-keypad, and besides all the other data that you see, you’ll be interested in the small negative number that appears at the top of the display,in the same location where normally you would find the bars for connection quality.
Any number here below -50, -49,-48… is good.
Posted by robert1014
23 September 2008 @ 7am
Hmmm…I’ve never had any dropped calls and have not ever noticed any problem with signal strength. Yet when I dialed up this field test, I got a number of
-87. If any number BELOW -50 is good, then I should be noticing poor connectivity with -87, shouldn’t I?
This doesn’t make me doubt the consistent quality of my iPhone functionality, but I do question these numbers.
Can anyone elaborate on what this test really shows or what the number really means?
Posted by denaliT
23 September 2008 @ 9am
How do I get the bars back once I am done with the looking at the db meter?
Anyone have success in doing this?
Posted by GaryPSU
23 September 2008 @ 11am
At home and in my office, my signal strength is regularly -95, -100, etc., but I still get good reception and no dropped calls.
Posted by brianf
23 September 2008 @ 11am
-61 here
Note the article:
http://www.iphoneatlas.com/2008/09/23/att-chief-admits-iphone-3g-blunders/
ATT’s CTO admits failure of their network to handle the increase in traffic due to the iPhone.
Posted by CyStarkman
25 September 2008 @ 10pm
It doesn’t say much for an iPhone site when the people writing for it don’t know basic things to do with the iPhone or networks.
Bars are whatever, on any phone. Some days it seems that the journalists of the world only discovered mobile phones when the iPhone arrived. It’s comical.
Or is it just that the journalists are in the USA and like the “rest” of the population DO actually think that Apple invented 3G and the launch of the iPhone was the launch of 3G. (Rest is a generalisation and not meant to represent people with brains and actual industry knowledge)
I am in one of the most remote yet populated (27,000) places and the iPhone on 3G is fast enough to play YouTube videos, live. Of course I am in a country that has a 3G network.
Makes all the difference you know