12 April, 2011

What do mobile phone signal bars mean?

Stupid Nokia N73
It's a constant moan when trying to use a mobile 'phone at 'The Wharf', "I've got full bars, but I can't make a call!"...this annoyed me...if we are at (apparently) full signal strength, what on earth is going on? It turns out, those silly bars? You can basically ignore. Apart from being a subjective measurement (varying from device to device), the absolute killer is that they are purely a measurement of signal+noise...that microwave oven running nearby? Those computer monitors? Those other mobile telephones near you? All that noise that's completely useless for making calls? Yep, they are all added up into your happy signal bars...it's a waste of your time even looking at them...

Want to know what your *actual*, (error corrected) connection level is? It's actually pretty easy-

On Android, go into "Settings", "About Phone", "Network"...

On an iPhone (you lot aren't trusted to know this information, as Apple routinely fib about how good their devices are) so you need to trick your brick into an engineers testing mode - dial *3001#12345#* and hit Call...

The number you are interested in is the dBm (the error corrected measurement), on your 'droid it's under signal strength, on the iPhone it's in the top left of the screen, and (if I have understood correctly) you read it thusly...

-63 (ish) - Perfect signal, i.e. you are practically feet away from the nearest base station
-89 (ish) - Borderline for successful communication
-103 (ish) - Basically useless, anything much less than this is "no signal"


Up on the 22nd floor, my 'phone waves wildly between -70 and -112, as does my neighbours iPhone, so there's not much surprise service is slightly erratic up here in the clouds, down on the ground, and I've walked around a *lot*, everywhere I have checked is a totally solid -63, so absolutely no problem with connection, our problem in 'The Wharf' would appear to be the sheer number of people connecting to the base stations trying to make calls, so mystery solved, plenty of coverage, but not enough bandwidth - mobile operators? Care to help us out?

Anyway, this should (at least) help you diagnose exactly what is going on when your telephone is being silly...

8 comments:

Mobile Signal Booster said...

My android galaxy ace is on "-97" dBm and is showing "6 asu" - asu means ACTIVE SET UPDATES so this represents the amount of updates from phone to tower.

Unknown said...


You have shared a great information about T Mobile Signal Booster and Best WIFI Booster. Which are very informative for

us.Thanks

Unknown said...


You have shared a great information about T Mobile Signal Booster and Best WIFI Booster. Which are very informative for

us.Thanks

Unknown said...



This is an intresting blog that you have posted, you shares a lot of things about WIFI Amplifier, 3G Repeater and Best WIFI Booste. Which are very informative for

us.Thanks

Unknown said...


You have shared a great information about Vodaphone Signal Booster and T Mobile Signal Booster. Which are very informative for us.Thanks

Unknown said...


This is an intresting blog that you have posted, you shares a lot of things about Mobile Phone Coverage, O2 Mobile Signal Booster and T Mobile Signal Booster. Which are very informative for

us.Thanks

Unknown said...



You have shared a great information about WIFI Amplifier and Best WIFI Booster. Which are very informative for us.Thanks

Unknown said...



This is an intresting blog that you have posted, you shares a lot of things about Best Mobile Phone Signal Booster UK, Orange Mobile Signal Booster and

Vodafone Mobile Signal Booster.

Which are very informative for us.Thanks