I have been studying how radio signals work lately trying to get my ham radio license. I then realized that phone calls and texts are essentially radio signals. What sort of signal are they? What frequencies do cell phones calls operate on? Is there a way to intercept and decode sms text messages using some sort of reciever? How are they encoded and decoded? This is just for hypothetical reasons. I have no interest in trying to intercept phone calls or anything.
In: 5
Most LTE cell signal is in the 700MHz band. Within this band there are channels of varying bandwidth between 5 and 20MHz. These channels work similar to how CB and GMRS channels work (since you are learning about amateur radio) but they won’t sound like FM signals if you were just listening to them. Most of them are a digital mode. Analog modes went away with 2G.
There are other 4G and 5G frequencies, the 700 band is just a popular one.
Yes, you can *sniff* for call/text data using devices that mimic a cell phone tower — essentially it’s just a radio receiver tuned to the cell phone frequency bands. Law enforcement uses Stingray devices as a sort of ‘man-in-the-middle’ attack to surveil targets. They have to have a warrant, though.
End to end encryption apps make data a bit harder to read, even if intercepted.
I don’t think that the voice cell signal is encrypted by default, though.
Latest Answers