View Full Version : Techs please?

Honor Bright
12-16-2015, 01:42 AM
Is it possible to hijack a radio station by bluetooth and interrupt its signal with white noise?
Is it possible to do this at all? If so, how?

Thank you! :)

Casey Karp
12-16-2015, 03:16 AM
OK, not a radio engineer by any means, but I've done a little reading on the subject. Take with a grain of salt. ;-)

By bluetooth? I'm going to say no to that--not only are the frequencies used by bluetooth very different from broadcast radio, but bluetooth is deliberately low-powered. Without special gear at the receiving end, you're not even going to detect a bluetooth signal more than a few feet away. So your radio station would have to cooperate in being hijacked.

Are you trying to blank out the station for everyone or just for a certain person? If the latter, a sufficiently powerful transmitter near the victim could drown out the station--classic jamming. But if you're trying to take the station down completely, you would pretty much have to get into the facility and insert your white noise somewhere into the wired connection between their mixing booth and the transmitter.

King Neptune
12-16-2015, 03:20 AM
All of the radio stations I have seen have cables from station to antenna. There may be some wireless somewhere, but they have no reason to change the basics. If your goal is to have the station transmitting white noise, then cutting the cable would be required. I believe the transmitter would still be putting out a carrier wave, which would not be white noise, because it would be on the frequency of the station.

Honor Bright
12-16-2015, 04:16 AM
Honestly, I can't remember where I got bluetooth lol. I went back on a draft from a couple months ago today. And just blank out for one person in a vehicle. I used her antenna? A transmitter is a wonderful word to use. Thank you!

Honor Bright
12-16-2015, 04:20 AM
Is static enough as opposed to white noise? As if it were flipping up the station by a point?

King Neptune
12-16-2015, 06:02 AM
Is static enough as opposed to white noise? As if it were flipping up the station by a point?

Somehow you would have to cut off the modulated signal, music, voice, etc. That's the stuff that sounds like anything. The transmitter will put out many watts of power that is modulated by the input signal. The transmitter just steps up the power and sends the signal out, and it will continue putting out the power if the input signal is cut off.

If you just want to change the signal that your character is receiving, then that might work without chopping (or unplugging) cables. You would have to change the source for her radio signal from the antenna to something that would pick up what you want (a different antenna); all it would need would be a switch that you could operate from outside.

Honor Bright
12-16-2015, 07:03 AM
That actually ends up fitting very well! I can justify that. Thank you so much for your insight!

12-16-2015, 07:30 AM
A radio receiver will pick up the strongest source, be it a commercial radio station or a pirate signal three feet away. If the signal contents of a specific AM/FM carrier frequency is white noise, then you have just effectively blocked that specific AM/FM station. If your signal source covers all carrier frequencies, then you have disabled the receiver; tuning a station is no longer possible.

You can buy a battery-operated FM radio transmitters that you can plug your iPhone in for under $10. They are designed to provide a quick way to play your iPhone on the car's radio; this is very useful for older car models that don't have Bluetooth or an audio jack. (example: http://www.ebay.ca/sch/i.html?_nkw=iphone+fm+transmitter). If you want to override a commercial station, just key in the correct frequency.

Someone with malign intents could piece together a smartphone and an FM transmitter and hide it in the truck of the victim's car. Whatever the smartphone is programmed to play - a song, stream down something from a web sit, etc - could be made to stomp the reception of a commercial FM station.


Drachen Jager
12-16-2015, 08:29 AM
Most radio stations run their signal through a computer system before it's broadcast these days. Theoretically you could hack that with bluetooth, but it would require some pretty sloppy/bizarre system management from the IT guys. A wireless computer would be more realistic, potentially you could hack the station's computer system and insert anything you wanted in to the signal. It wouldn't take them too long to figure it out, but you might five to ten minutes once the tech support staff is aware and on site (smaller stations won't have 24 hour techs on site).

Bing Z
12-16-2015, 04:44 PM
A friend is a radio show host for an enthusiasts-operated Latin music station. She runs her show out of a laptop from her basement. I suppose it isn't too hard to hack into her system (Windowz, wifi, and all) and ruin her show. But probably not with Bluetooth, which is a synchronization system that has to be set up from both ends. Obviously, if you can have physical access to her laptop or wifi router, you can do anything, but otherwise Bluetooth is out.

Drachen Jager
12-17-2015, 12:17 AM
Bing, Bluetooth is totally hackable. I don't know what you mean by 'set up' on both ends. If it's turned on, it's hackable, but whether you can gain full access to the station's computers that way is fairly iffy. You can download programs to your Android that allow you to discover any bluetooth enabled device within range and gain access to most of them.

Bing Z
12-17-2015, 12:57 AM
Don't you need to pair the devices before you can connect them via Bluetooth? Or can a hacker bypass the pairing and force the target device to pass out or receive data?

Drachen Jager
12-17-2015, 02:05 AM
Yep, bluetooth is totally vulnerable. There are various patches, but AFAIK, the hackers remain well ahead of the patches and many (perhaps most) users don't update often enough to protect themselves. It even has a word, bluesnarfing (actually, three words, depending on the type of access, there's bluejacking and bluebugging as well). Mostly access is limited to calendar, e-mails etc. but an enterprising hacker might be able to get deeper than that if security is lax.


12-17-2015, 04:27 AM
Is it possible to hijack a radio station by bluetooth and interrupt its signal with white noise?
Is it possible to do this at all? If so, how?

For bluetooth to work you'd have to be in the building. Easiest way to take it out is to hack the automated system at the broadcast antenna, which is often remote accessed and automated. Not hard to take it off the air, changing the broadcast is something else altogether. Keep in mind that the station will know and an engineer will be on site quite quickly to fix it.

What does your plot need?


12-18-2015, 04:32 PM
I would assume that if you could get root access / system administrator login on the station's computer system, you could make it send whatever you wanted to. A test signal perhaps.

I would consider using an unprotected wireless LAN access point instead of Bluetooth, many people don't think to set a password on those... it could just be "password" or "0000" etc... W-LAN has a longer range as well and no pairing etc. enters the picture. How you would get root access on one of the PCs on the LAN from the wireless, I don't currently know but it might be possible to use some kind of packet sniffer, port knocking, etc. software and brute-force some service running on the target, such as SSH or an HTML server (Apache?) that requires an open port. Depends how good the target's security would be. On an amateur station, it might be possible.

This could be done from a car parked nearby, from the sewer system, whatever... would only need the necessary knowledge.

Explaining this would need some technical knowledge to get it right and make it sound plausible.

Edit: Or if your hacker has the right connections, acquiring knowledge about some kind of zero-day exploit (hitherto unknown security flaw) in the operating system running on whatever the target is, might be possible too. This is not an everyday thing by far, though. Depends who the hacker is.