Cell Phone Jammer

Why not just buy one. Movie theatres install these devices regularly now.

J

you can buy jammers

Thank you, all of you, for the feedback and links. I had assumed that cell phone jammers would be illegal to use and therefore that no one would sell them. Now I know better. If they cost much I might still want to try to build one anyway. I don't know what restrictions might apply to using one, but I will check into this before deploying the jammer.

How about disallowing people to have cell phones during game play?

Don't allow headphones... if people MUST have music while playing at least tell them to get an mp3 player and not use their cell phone as one.

I am curious... how can they cheat with out you knowing? They would have to be texting (or talking) to their source for communication... or they have an incredibly small and advanced camera to transmit game play.

How about disallowing people to have cell phones during game play?

It would not be practical to search every player and spectator (who could hand a cell phone to a player), especially considering how small cell phones and related devices have become. Chess tournaments barely have enough staff to run the event, let alone pat down hundreds of people. And chessplayers -- a very individualistic and litigious bunch -- would not submit to it, thereby discouraging participation in an already struggling sport (unlike in Europe, chess in the U.S. has little prestige). Believe it or not, the world governing body in chess (FIDE) tried to require drug testing for chessplayers. This caused such an uproar (especially among the elite players) that FIDE had to back down.

Don't allow headphones... if people MUST have music while playing at least tell them to get an mp3 player and not use their cell phone as one.

Again, players would not tolerate this restriction. Head phones have been commonplace in chess tournaments for decades. I can understand why -- it is really helpful to block out noise when calculating an intricate combination. I find music distracting, so I wear ear-plugs instead.

I am curious... how can they cheat with out you knowing? They would have to be texting (or talking) to their source for communication... or they have an incredibly small and advanced camera to transmit game play.

Simple. Say I am playing against Vladimir in the last round, and a money prize is at stake. Spectators are allowed to wander around and watch games. So Vlad's friend Boris casually strolls by, makes a mental note of the chessboard, and walks out of the playing hall. He then inputs the position into a grandmaster-strength chess engine (available for $40) running on his palm-top computer, and discretely radios the best move to Vlad, who is wearing headphones plugged into an FM reciever (perhaps disguised as an MP3 player). This has no doubt happened countless times. Two chessplayers were busted for such cheating at last year's World Open in Philidelphia. The tournament organizers got suspicious when two players with mediocre ratings started crushing strong grandmasters. The tournament director confronted them, but one managed to run to the restroom and flush the incriminating technology down the toilet before it could be spotted. In the next round, without the computer help, he played like a "fish" (a weak novice) and lost. If he had not been exposed, he would have probably walked off with thousands of dollars in cash prizes. The other known cheater (no connection to the first one) was caught "red-handed" with a miniture device in his ear. He insisted that it was a hearing aid, but a quick internet search on the brand and model number revealed it to be a FM reciever sold by a company specializing in espionage technology. He was immediately ejected from the tournament and banned from U.S. tournaments for life. Jamming FM radio frequencies inside the playing hall sounds like the best way to deal with this type of cheating. Next we need to figure out how to deal with the cheaters who skip the transmitter and instead simply operate the "pocket-grandmaster" themselves during frequent bathroom breaks.

Aaaarrrrrrggghhhhhh!

wearing headphones plugged into an FM reciever (perhaps disguised as an MP3 player).

Hate to say it but MP3 players may include radio receivers. Last month I purchased a Sandisk Sansa® e260R Rhapsody 4GB MP3 Player which includes a FM radio tuner. I often tune into an FM signal transmitted at my health club while working out.

Info on making your own:

http://www.ladyada.net/make/wavebubble/

Info on making your own:

http://www.ladyada.net/make/wavebubble/

Thank you! Exactly what I need. If the commercially available legal jammers aren't up to the task, then I would like to try to build Wave Bubble's self-tuning version. The site claims that the FCC prohibits sale of the device. If true, then this is a great endorsement.

Hi Svengali,

Yes this would be illegal - to block cellular spectrum is to take away a resource that a company paid the government for the right to use, but enough on that part.

I would approach this differently. Amateur radio operators host contests called 'Fox Hunts' in which a low-power transmitter is hidden by the organizer, and the players must search for it. I would contact your local amateur radio club prior to the next tournament, and find out if they are interested in helping you out. At the tournament, you would state that no receivers or transmitters of any kind are to be used in the tournament area.

Some amateur radio clubs have members that are techs/engineers from the local cellular company, so they can bring in the big test sets to ensure that no one is using their phones. Certainly, the AM/FM part should be easy to solve, but I do think that you will have to strip the cell phones from the players. This is because a text message, sent in a short burst of RF, would be next to impossible to catch, and the spectators' cellphones would make it impossible to tell the difference between cellphones on players or on spectators. And finally, all cell phones regularly send signals back to the network while they are in standby mode, so there is a periodic background chatter of RF even if the phone is not being used.

By the way, I am an engineer for a CDMA-based cellphone company.

Greg

Hi Greg, see my replies below...

Yes this would be illegal - to block cellular spectrum is to take away a resource that a company paid the government for the right to use

I won't deprive anyone of any legitimate service, since cell phone *use* is not allowed inside the playing hall during tournaments. If a person needs to make or receive a call, they must simply leave the room (just like in movie theaters).

At the tournament, you would state that no receivers or transmitters of any kind are to be used in the tournament area.

As I explained before, we cannot ban cell phones (we have no logistical way to enforce such a restriction, and the players know it). And of course simply announcing to the crowd that "transmitters and recievers are forbidden" would do no good because the cheaters are fully aware that they are cheating, and therefore have no intention to follow the rules. It would be just as effective as announcing that "cheating is forbidden". No, this is an "arms race" -- the easily concealed technology used for cheating can only be effectively countered by yet more technology.

but I do think that you will have to strip the cell phones from the players.

Out of the question, as I explained before. Likewise for MP3 players, FM recievers, etc (who knows what other technology cheaters will put to use). Even if I must technically break the law, I plan to jam the FM spectrum in my personal vicinity during match games (unless the tournament organizers wize up, save me the trouble, and set up a jammer themselves). Since I will keep the power level very low, it should not affect communications outside the playing hall.

Ah Svengali,

I see your mind has been made up. In any situation with cheaters, one gets ahead, and one doesn't. Perhaps you have been cheated, and thus fall in the latter category.

Use this opportunity to clean the sport by bringing a Faraday cage to your next match. Ask your opponent to sit inside the Faraday cage and offer that s/he can bring whatever device they want inside the 'cage'.

I wish you well. One last item; as you jam the cellular spectrum, please be kind enough to turn it off if someone keels over from a heart attack. Your turning off the jammer will allow someone to dial 911 if required.

Greg

I wish you well. One last item; as you jam the cellular spectrum, please be kind enough to turn it off if someone keels over from a heart attack. Your turning off the jammer will allow someone to dial 911 if required.

Anyone who needs to make a cell phone call simply needs to walk out of the room. I have witnessed people fall ill at tournaments. After helping the ill person out of the room, the phone call was made outside the door. This is what normally happens even when no jammer is operating. No need to disrupt the entire tournament involving hundreds of people (which would only cause additional stress for the victim, and "rubber-necking" which would interfere with rescue workers). Your insinuation that I would endanger anyone sounds like hyperbole -- the phones would still work outside the room.

Yes, my mind is made up. I didn't start this thread to debate ethics. I came for technical information, and I got it. What I intend to do is no different than what some movie thearters and other mass venues already do, except that my jammer would emit a much weaker signal since I only want to affect my personal space, not the entire room. And of course I would turn my jammer off if I knew that anyone nearby needed to make an emergency cell phone call.