Jamming planned in DC

[doctordave]

Intriguing news story yesterday: Some federal law enforcement agencies have publicly indicated that they plan on heavily relying on jamming devices to deter the potential for a well-timed detonation of some sort during the upcoming event in January. Will be very interesting to see how such jamming (if actually pursued) could be utilized without interfering w/ comms from the various fed/state/local officers positioned in downtown DC.

 

[baseball214]

how about secret service or they already jamming devices? anyway do you or anybody know what kind of radios they using & what frequencies too?

 

[n4voxgill]

You may recall that a bomb did not go off in spain because the cellphone frequencies were being jammed and that was how they were going to set the bomb off. There were stories about Los Angeles trying to do the same thinng. In some places they are now jamming the cellphones in theaters and restaraunts. The area to be jammed would be very small just around the capitol and would have to cover all cellphone frequencies.

 

[n3bxv]

would have to cover all cellphone frequencies.

And how would that affect intermingled 800mhz public safety Frequencies?

 

[N_Jay]

would have to cover all cellphone frequencies.

And how would that affect intermingled 800mhz public safety Frequencies?

There aren't any! :twisted:

(Nextel is not in the Cell phone band)

 

[n3bxv]

I knew someone would say that!

I was of course speaking in generic terms, if you're going to jam and have it be effective, it would have to jam both "Cell phones" and NexHELL bands....

 

[N_Jay]

I knew someone would say that!

I was of course speaking in generic terms, if you're going to jam and have it be effective, it would have to jam both "Cell phones" and NexHELL bands....

And what about all the government agencies useing Nextel?

I would love to see the original artical.
My guess it has 1/2 facts quoted out of context.

 

[n4voxgill]

it would block them and yes cingular and some other carriers would be impacted. I don't know if there are any 800 MHz police systems covering the Capitol, but if they do jam it would impact them, for the immediate area.

They are now selling panneling that has a copper content that signals can't penetrate that are being used in expensive restaraunts. Radio system managers are very concerned because it will interfere with public safety. We discussed that at APCO more than two years ago.

gill

 

[dc2wheel]

DC Police and most federal agencies [including Secret Service] in the area are on VHF or UHF trunked systems, although DC Fire/EMS & most surrounding counties are almost all on trunked 800mhz systems. My guess [and it's a total shot in the dark] is that if there is any jamming done it will be very localized/small area surrounding the motorcade.

Apparently Nextel has been installing additional antennas in the area, including on a tall apartment building across the street from my work. They actually asked to store huge spools of cable and other equipment on our property, but balked when I asked how much they would be willing to pay us :roll:

I also read somewhere recently about Nextel having mobile antenna trucks on site at Dulles Airport available if additional capacity is needed.

 

[N_Jay]

. . My guess [and it's a total shot in the dark] is that if there is any jamming done it will be very localized/small area surrounding the motorcade.
. . . .quote]

A google serch does not show any news stories that match the original post! :roll: :roll: :roll:

 

[dc2wheel]

A google serch does not show any news stories that match the original post! :roll: :roll: :roll:

Yeah, I've seen a few - here's one I could find quickly:

http://washingtontimes.com/national/20041223-104022-5789r.htm

It's the Washington Times, so not exactly a reliable source [owned by the moonies cult], but I think it was an AP or newswire story, since it's basically verbatim for the other few I've seen, and that's most of what the Wash. Times tends to be anyway.
-dc2wheel

 

[N_Jay]

A google serch does not show any news stories that match the original post! :roll: :roll: :roll:

Yeah, I've seen a few - here's one I could find quickly:

http://washingtontimes.com/national/20041223-104022-5789r.htm

It's the Washington Times, so not exactly a reliable source [owned by the moonies cult], but I think it was an AP or newswire story, since it's basically verbatim for the other few I've seen, and that's most of what the Wash. Times tends to be anyway.
-dc2wheel

Looks like it is Washington Times only. :?

The AP article does not have the reference. :wink:

 

[n4voxgill]

They only have to jam for a couple of blocks. The secret service is not going to worry about knocking out cellphones for 10 minutes or so. If the only public safety users impacted are fire, ems then that is easy to get around by having them issued portables operting in the 1380144 or 148-150 range. When I set up the communications for World Cup Soccer, the department of defense gave me all of the portable radios and frequencies I wanted.

A van moving along the parade route could easily send out a blocking signal. I don't know what method was used in spain, but it worked.

This is no big deal when dealing with a threat.

 

[N_Jay]

They only have to jam for a couple of blocks. The secret service is not going to worry about knocking out cellphones for 10 minutes or so. If the only public safety users impacted are fire, ems then that is easy to get around by having them issued portables operting in the 1380144 or 148-150 range. When I set up the communications for World Cup Soccer, the department of defense gave me all of the portable radios and frequencies I wanted.

A van moving along the parade route could easily send out a blocking signal. I don't know what method was used in spain, but it worked.

This is no big deal when dealing with a threat.

I know one of the bombs is Spain did not go off, but to you have a crediable source that says they blocked the cellphone? :?

 

[SkyPager]

That's how I would do it. Two vehicles similar to Road Runner, one in front one in the rear would generate a moving RF bubble. Assume that they would generate broadbanded signal. (DC-daylight). What I don't know about jamming is would the signal be randomly modulated or just a carrier?

Two points to ponder cell phone bands differ in many countries. In Japan they are 935 MHz. Don't know about Spain.

Also simple is sometimes better. An amplified garage door opener would work just as well.

 

[N_Jay]

That's how I would do it. Two vehicles similar to Road Runner, one in front one in the rear would generate a moving RF bubble. Assume that they would generate broadbanded signal. (DC-daylight). What I don't know about jamming is would the signal be randomly modulated or just a carrier?

Two points to ponder cell phone bands differ in many countries. In Japan they are 935 MHz. Don't know about Spain.

Also simple is sometimes better. An amplified garage door opener would work just as well.

Well if that is how you would do it, I am glad you are not in charge.

If you just generate noise, how do you know if you have generated enough to overwhelm the intended signal?

If you try to block all frequencies, how far outside the "bubble" will you also be causing interference. What about other public safety frequencies?

If I had to guess, I would say;
1) the reporter did not understand what he was told, or was lied to intentionally, or the person taking to him did not know what was going on.

2) if they do have the blocking equipment, it is the same systems used other places designed to specifically block cellular (I think by looking for control channels and generating a signal designed to prevent a handset from synking with the data)

3) probaly won't use it, and it would probably be ineffective if they did. (for lots of reasons, like the bad guys using Nextel, or other non-cellular systems)

 

[2gigch1]

I was Jammed

Just as a follow up to the topic the vice president's motorcade blew by me in my microwave tv truck last month on Mass Ave. Third vehicle in line was a black Excursion with four three foot antennas each about and inch and a half thick. Four blocks away my company 2-way (450 mhz), scanners and cell phones (analog Verizon & Cingular) all went belly up and continued to stay that way until they all passed.

Fascinating to watch.

 

[Starion]

That's how I would do it. Two vehicles similar to Road Runner, one in front one in the rear would generate a moving RF bubble. Assume that they would generate broadbanded signal. (DC-daylight). What I don't know about jamming is would the signal be randomly modulated or just a carrier?

Two points to ponder cell phone bands differ in many countries. In Japan they are 935 MHz. Don't know about Spain.

Also simple is sometimes better. An amplified garage door opener would work just as well.

I thought Japan uses WCDMA on the frequencies of 1920-1980 and 2110-2170.

Spain uses the 900 and 1800 GSM bands.

Thanks for sharing your interesting story. I don't know any thing about jamming.

 

[N_Jay]

Re: I was Jammed

Just as a follow up to the topic the vice president's motorcade blew by me in my microwave tv truck last month on Mass Ave. Third vehicle in line was a black Excursion with four three foot antennas each about and inch and a half thick. Four blocks away my company 2-way (450 mhz), scanners and cell phones (analog Verizon & Cingular) all went belly up and continued to stay that way until they all passed.

Fascinating to watch.

Wow, 4 blocks away, that would be about a 12 to 16 block area without communications and not a peep in the media. :roll:

Oh, but they were probably ordered not to report on it! :wink:

 

[2gigch1]

Nah, none of us been 'ordered' to do anything. Reality is few of my compatriots even knew or realized something was up (many don't bother with scanners) and when I brought up the topic the usual answer was 'yeah I've heard that, is that what that was?'

Generally we have agreed that there is no real purpose in reporting this topic.