But we can’t know that. So the best way to determine the strength of signal received by your phone is to view the signal strength reading. These readings are expressed in decibels (dBm), a standard unit of measure. They allow us to know when we are receiving a stronger signal or a weaker signal.

Please notice that signal strength is expressed as a negative number and can range from about -30 to -110. On certain phones, the number may show as positive in test mode. In such cases, convert it to negative. For example, 60 dBm is actually -60 dBm. The closer the number is to zero, the better signal your phone is receiving. Thus, a reading of -60 dBm is a stronger signal than -75 dBm. Some phones may show either a 1x/3G reading or a 4G/LTE reading at the top of the phone.

It is important to know your carrier’s signal strength, as this will help determine if you need a booster and where you need the boosted signal to go. Check out this video for tips on improving your cell signal:

ANDROID FIELD TEST MODE INSTRUCTIONS:

Most Android phone models allow the user to view signal strength readings by navigating the device’s menu tree. Finding the right menu screen varies across phone manufacturers, models and versions of Android OS. A typical navigation sequence is Settings – About Phone – Status or Network – Signal Strength or Network Type and Strength.

An alternate nav sequence for some Android phones is Settings – More Options or More Settings – About Phone – Mobile Networks – Signal Strength. Some experimenting with the menus on your Android phone should get you to the dBm reading.

Finally, if necessary, you may have to contact your phone manufacturer’s customer support group for help.

iPhone models require the user to access the phone’s ‘Field Test Mode’ in order to see the signal strength.

NEW iOS UPDATE FIELD TEST MODE INSTRUCTIONS:

For use on an iPhone 5 and higher, running on iOS 9 or newer, go in to your Settings, then Cellular, then Cellular Data Options, then change the Enable LTE status to OFF (after testing you can go back in and turn the LTE back on or to Data Only):

1. Dial *3001#12345#*
2. Press CALL
3. Hold the power button for about 5-7 seconds until you see the “slide to power off” screen.
4. Do NOT power off the phone!
5. Hold the home button (round button at the bottom) for about 5-7 seconds.
6. It will return you to the home screen and the negative decibel reading will be at the top of your screen.

*If you do not wish for the negative number to be there permanently, you can dial the sequence again and just hit “back to phone” and it’ll return your phone to the dots/bars again.*

If using an iPhone 5 or newer, on iOS softwareolder than iOS 9, you will need to go into your Settings, then Cellular, and turn OFF the LTE (you can turn the LTE back on or to Data Only after this test). From your phone’s keypad, dial *3001#12345#* and press the CALL button. Once you press CALL, your screen will change and display “Test Mode” and a negative number will display in the upper left-hand side of your screen. The negative number is your signal reading in dBm. Same rules as above apply for weak and strong signals.*

ALTERNATIVE FIELD TEST MODES
Thanks to a 3rd party, we have provided you a list of test mode instructions for other types of phones. To find a possible test mode for your phone (other than what’s already been mentioned above), you can visit the following link: http://www.wpsantennas.com/pdf/testmode/FieldTestModes.pdf