Vulnerabilities of Wireless Two-way Communications

a reply to: Bedlam

Excellent information Bedlam, you never disappoint me with your knowledge in these matters. I am supposing that "HAND" stands for High Altitude Nuclear Detonation", acronyms, gotta love them.

You've now got me interested in ground wave propagation and methods to utilize this effect. Thanks for peaking my interest in this area.

There is a booklet published in Europe around 1985, entitled "Radio Is My Bomb". It discusses pirate FM radio. The transmitters are not nearly as difficult to construct as you might imagine.

A key benefit is that anyone within range and knowing the right frequency can hear you. Back in the Old Days, pirate broadcasters would plaster the target area with handbills giving the time and date of the next broadcast. They'd then build a disposable transmitter, and place it difficult terrain, along with the audio feed (on digital audio tape!!!). It would often take government authorities only seconds to triangulate they signal source, but an hour or more to physically locate the transmitter. The authors described radio pirates in the UK who were able to place their transmitters on the roof of an apartment building, and then add illegal locks to the access door. While "The Man" was trying to locate bolt-cutters, pirates would climb up on the roof from a top floor and retrieve their equipment before the cops got it!!!

Imagine how much more could be done now, in the days of thumb-drives, when the audio file could be switched on an off by a remote control, and broadcast one "show" from multiple locations.

All of this might seem pretty far afield from the OP's discussion of 2-way communication. But the system I am describing is exactly how government spies use "numbers stations" to communicate with their spies in a foreign (enemy) state.

Basically, the "Base" needs to be outside of government jurisdiction, or somewhere they cannot reach to stop the broadcast. The man in the field can use another form of communication, and the answers are broadcast over FM in code. You don't need to know the field-spy's location, in order to direct him. And if you are using a "one-time pad" means of encryption, your broadcast is unbreakable.

a reply to: redempsh

Redempsh, although pirate radio is outside the realm of this discussion, it is an interesting subject none-the-less. I believe that some of the earliest pirate stations were located in international waters off the coast of England and broadcast rock-n-roll that was banned from the airways there. Personally I'd love to hear pirate radio if there was a station around here. Great stuff.

Now this idea of multiple stations switching broadcast locations is an interesting idea for stealth broadcasting any kind of signal. That is a great idea to think about and to put into my communications dark ops files.

Here is an idea based on the pirate radio concept that would actually be legal to do for stealth communications. This one is from my dark ops files.

A low power AM radio transmitter, transmitting on the commercial AM band, can be used legally without a license making it possible to deliver information in a highly localized area. The output is restricted to 100 Milliwatts but with a good antenna, it can cover an area of a mile or so in open terrian and beyond that when placed on high ground. Such a transmitter could be placed in a secret meeting area to broadcast information from a repeater or from a recorded message. The operative could go to the designated area and pick up the broadcast from their car radio or a portable radio on an unused broadcast frequency.

a reply to: MichiganSwampBuck

Ya know, during world war 2, German submarines would broadcast so briefly that the Allies had difficulty triangulating their location with the manual equipment then in use. The Germans broadcast the telegraphy at such an accelerated pace that no one could write it down that fast. Allied troops became fatigued because they waited around the clock to try and record the message as quickly as it was sent. Usually the burst was done before they'd gotten their equipment to the correct frequency and recording speed.

The German subs had a typewriter that produced a cellophane tape with holes punched in it. When the tape was run through the telegraph, it was played at about 16X normal speed.

An amateur could do this as well. It would sound like an old audio modem. I bet.

Here is an example of how the government will block your cell phone or WiFi signal with a jamming frequency during times of peace. In this article they show how the government will use this to prevent possible bomb detonation form a cell phone or how a political candidate (in this case Hillery Clinton) will stop people from reporting at events.

First there were reports that the convention had installed white noise generators over the sections that were pro-Bernie states. The white noise significantly drowns out the voices of anyone shouting in the radius.

Now reporters are coming forward to explain how their cellular and wifi devices were blacked out from transmitting images, posts, texts and communications when they encountered the perimeter of the convention at the Wells Fargo Center.

Di d the DNC Keep Press Silent With Cell Jamming Signal?

Perhaps the reporters could have used lower frequencies radios to send the information outside of the area being jammed for cell phone and WiFi devices where it could then be resent without jamming interference.