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Since even phones can receive and understand the other systems' signals, if one wants to jam, one would probably jam them all...


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Cell phone signals can be jammed fairly easily. It's illegal to do-so in the states, but the devices are pretty easily obtained from what I've read. I'd imagine even easier in other countries.

Disclosure: I work for a company in this field.

They are easy to jam if you don't mind also not having GPS, Wifi and 3G/4G/5G service. You can do selective jamming but this is much more sophisticated


Jam the transmission signals?

They can jam the other frequencies so that they aren't available.

I certainly hope that there's some sort of channel-hopping strategy in place to prevent accidental jamming. In fact, I would hope that "can't be accidentally jammed by a bunch of 14 year olds on their cell phones," is a lower-bounds for measuring the efficacy of the system.

Android phones can be made to do wifi jamming... ;-) Seems convenient all things considered...

http://www.youtube.com/watch?v=DwYOtf4fI0Q


you don't have to understand a signal to jam it.

unless it also has frequency hopping when it senses a jam.


Jamming signals is way easier in that regard, but I don’t know how effective it is in practice.

If I were go to such great lengths and finally resort to order a multi-frequency signal jammer isn't the next follow-up question: Is it powerful enough? Or could it disrupt like ... I don't know ... 911 calls in the vicinity? No experimenting? Really desperate, I guess.

A cheap $50 phone from 2010 can stay constantly connected to 6 base stations (at 6 different frequencies) and swap over between them in milliseconds.

You'll need to emit 100 times the power of a phone over a wide range of frequencies to jam them.

It's not even counter-productive, it is destructive. Don't suggest that as an idea in a plane.


Can't they just jam the frequencies instead?

Jamming would run afoul of the FCC. Now having one or more WAPs randomly modulate their signal strength should do the trick

It would be very difficult to jam a CDMA signal.

True, but jamming is even easier (and cheaper) -- particularly if you aren't especially concerned about incidentally jamming nearby frequencies.

What? You can Trivially jam it.

Jamming is done at the receiver, not the transmitter. The fact that the power is so low makes it far easier to jam.


Those are great points. I hadn't considered the ability to jam signals at all. That seems like a pretty huge challenge to overcome actually.

Yes, and it is legal, and commonly done.

You are allowed to broadcast a cell phone tower signal and MiTM the connection.

You are not forcing others to connect to your signal.

The spirit of this freedom is even emblazoned on every compliant device, look for the FCC warning.

As for jamming, that is entirely unrelated, not comparable, and illegal. It would be akin to blaring loud music and lights.


Actually, it's rather 'easy' to jam DSSS/CDMA signals - Especially for nation states. There are a variety of techniques and tools that can be used.

Surely the "jammers" could just broadcast their jamming signal over a large range of frequencies?
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