Posted by Admin on Aug 18, 2014
By now, most of us know not to rely on our new iPhone’s bars graphic as an indication of signal strength, and that we should locate the actual signal strength reading. The reason for this is that there are no set standards for the bars representation. Your latest iPhone 6s’s four or even five bars could well represent a weaker signal than my iPhone 5s’s three bars. But how could we know this? The only real way to determine the strength of signal your i-phone’s receiving, is to view the actual signal strength reading. These readings on our mobile iPhones and iPads are expressed in decibels, which is a standard unit of measure. It is this measurement that tells us when we're receiving a weaker or stronger signal.
Keep in mind that, when your Apple's signal strength is measured in decibels (dBm), it will usually be expressed as a negative number, and this number can range from between -32 to -110. This number may show as a positive number in test mode on certain iphone models. By this, we mean that 50 dBm is actually -50 dBm. Remember that your Apple phone or tablet is receiving a better signal, the closer the number is to zero. Therefore, a reading of -50 dBm is a stronger signal than a reading of -70 dBm. All clear?
In order to view an iPhone's signal strength reading, the user is required to access the phone's IOS Field Test Mode.
If you're using an iPhone 5 or newer, with IOS software that is older than iOS 9, then you should go into your Settings > Cellular > turn OFF the LTE. Then, dial *3001#12345#* from your phone's keypad and press the green "CALL" button. Once you have done this, your screen will change and display "Test Mode". On the upper left-hand side of your screen you will see a negative number. That negative number is your signal reading in dBm. The same rules as above apply for both strong and weak signals.*
The test mode instructions above will not work if you have recently updated your iPhone to the new iOS 9. The instructions are actually quite similar but do require some extra steps, as shown below:
For iPhone 5 and higher, you need to go to your Settings > Cellular > turn OFF the "LTE"
• Dial *3001#12345#*
• Press CALL
• Hold the Power button for around 5 to 7 seconds, until you're able to see the, "Slide to Power Off" screen
• Do not power off the phone!
• Hold the, "Home button" for around 5 to 7 seconds. This is the big circular button facing you at the bottom.
• You will be returned to the, "Home" screen, and at the top of your screen you will see the negative decibel reading.
* If you do not want the negative number to be there permanently, simply dial the sequence again and hit Back to Phone: Your phone will be returned to the dots/ bars again.