The iPhone certainly is slick. I like the full-sized Web browser. There’s also a large, bright screen for viewing pictures. And, of course, it can play music from iTunes.
But, as you mention, cellular reception can be spotty. For some people, this is a deal breaker. So, prospective buyers should check up on the reception. This calls for a field service test.
Of course, AT&T’s coverage will vary in different areas. So, I wouldn’t just try out the phone in the store. Check elsewhere. Do the tests where you anticipate using the phone the most.
For example, do one at work and several areas at home. You may also want to do tests along frequently driven routes. (Do me a favor and park first!)
You will have to buy an iPhone to do the tests. You have 30 days to return it if reception is subpar.
A field service test isn’t difficult. But it is impossible unless you know code that unlocks the feature.
First, bring up the keypad in the iPhone’s phone application. Enter the following exactly (minus quotes): “*3001#12345#*.” Then, press Call.
The Field Test Mode will open. Select Cell Information. You’ll see a list of cellular towers to which the phone is connected. The towers are listed in descending order of strength.
You’ll also see information about the cell towers. It will be a string of letters and numbers. Don’t worry if you don’t understand them. Believe me, the information looks like gibberish!
Now, you’ll have to give the phone some time for the signal to stabilize. So take a look at the numbers after you’ve been in test mode for about 45 seconds. Hold it in your hand when you take the measurement.
You’ll see a negative number preceded by RX. This number represents the strength of the signal you’re receiving from a specific tower. It is measured in dBm.
The closer this number is to zero, the better the signal strength. For example, anything -60 or higher is very good reception. On the other hand, -100 would be very weak reception. When you hit -106, you probably won’t be able to make calls.
As I said, the closer the RX measurement is to zero, the better. But let me put the numbers into perspective for you. An increase of 3 dBm doubles the amount of radio frequency energy reaching the phone.
This should give you a good idea of how your iPhone’s reception will fare. But it isn’t foolproof. Cellular towers often adjust their power output. So the reception can change at any time.
Give this a try, I am going to,If I can get service outside my home.