[ale] OT: Cell phone signal blocker

[Thompson Freeman]

On 06/22/2009 12:11:02 PM, Vernard Martin wrote:
> ok, this is going to sound like I've been watching too
> many sci-fi
> movies but I want to obtain a device that can block cell
> phone reception
> in about a 10 to 20 yard radius. This is not for myself
> but for a friend
> of mine. He is one of those people that runs the Team
> Trivia events at a
> local sports bar. He is having a hard time with folks
> cheating by
> looking up the answers to trivia questions on their
> blackberries and
> such. He is hoping that he can block the signal they are
> using.

I have heard that there are such devices available  
(Europe?), although not legal in the US (FCC regs). There  
are also plans on the web (I think you can check through  
Make magazine, but I'm not sure) for plans, should you  
prefer to role your own. Actually making one and using it  
is illegal, but knowing how to make one isn't.

IANAL, but I think Faraday Cage like technologies to  
interrupt cell phone service remains legal, if not  
portable. Otherwise, the FCC would need to regulate against  
metal buildings 8-).

Another, possibly legal technology, would be to monitor the  
control bands for cell phones during the events, which may  
allow busting the cheaters. Pull the technology from the  
Gnu Radio project, and I'll bet the technical people here  
can whump something workable out. Nice thing about it would  
be the noninterference with a radio communication.

As pointed out elsewhere, the low tech "Hands on the table  
where I can see them" would be the most portable and least  
expensive.
> 
> I personally don't think its possible without introducing
> a helluva lot
> of signal noise in the area that will screw up other stuff
> (possible
> including human life) but I thought it was best to pose
> the question to
> the best set of techno-geeks that I know.


> 
> Any ideas? And yes, this does not address the issue of
> legality at the
> moment, :)