The system is an improvement on jammers which only block signals to mobile phones. This solves the problem of noisy interrruptions in public places like concert halls, libraries and lecture theaters. The device must be adopted by mobile manufacturers to work and requires legislation. The system consists of a TRANSMITTER located in a public place which sends a signal at a given frequency to all mobile phones in the vicinity. The phones have SOFTWARE/ HARDWARE which detects this signal and calculates it's intensity and or frequency to determine distance from source. If the distance is appropriate the mobile phone SWITCHES from RING to VIBRATE, without the user having to turn off the phone. When the phone leaves the vicinity, the ringer is switched on again.

A variation on this theme would be to have electronic gates similar to the checkout security systems in libraries. When you go through the gate, all mobiles are turned off, when you exit, all are turned on. Such a device could also be used in AIRPLANES to prevent mobile electronic equipment from being used in flight and interfering with avionics. e.g. a chip on the device would turn the device OFF when boarding, and ON capable when exiting.
-- johnchaughey, Nov 22 2001

Cellphone Disrupter http://www.halfbake...llphone_20Disruptor
The idea that inspired this one. [Aristotle, Nov 22 2001, last modified Oct 04 2004]

(?) Bluetooth folks are baking this http://www.cell-blo....com/Technology.htm
See Q-Zone on this page. Bluetooth enabled device is automatically told to be quiet in the affected area. [krelnik, Oct 14 2002, last modified Oct 04 2004]

Since your solution relies on legislation (compulsory devices) to put it into practice, why not just make mobile phone use illegal in certain places? There are also obvious civil liberties issues if your cinema/theatre/etc's blocking signal affects people outside your building. "Please turn off all mobile phone" signs would have much the same effect.

On the other hand, I can't think of a technical reason why this wouldn't work, if the signal was included in the information already exchanged between phone and base station.
-- pottedstu, Nov 22 2001


it's a good idea pity that it's illegal in few countries.I have checked with the australia and they say that using frequency to force phone to silence is also illegal. refer to http://www.aca.gov.au/aca_home/legislation/radcomm/declarations/index.htm some more to achieve this we need to get permission from the carriers of the specific country who already paid millions for the use of that bandwidth. a bit complicated but i still think there is a way out of it.
-- limtauhong, Apr 08 2004


I think you misread the idea, [limtauhong]. This isn't about jamming the phone, it's about the phone cooperating when sent a signal that means "Please turn off your ringer".
-- krelnik, Apr 08 2004


I didn't misread the idea. I know the difference between jamming a phone and sending a signal that turn off the ringer. But in order to send a signal to the mobile to off the ringer we still need to use the bandwidth which is already bought by the carrier.Unless we obtained permission,this cannot be done. secondly is that ,in australia currently is illegal to force other people phone into another action such as turn off ringer. I wanted to bring this idea of forcing off ringer into reality but after checking with australia communication authority, i found that it is illegal. Though it's illegal in australia but it is not for other countries.In future i think this idea is feasible. I am researching on this topic currently,if you have other information on this topic please send me info to tau.lim@student.adelaide.edu.au. cheers
-- limtauhong, Apr 09 2004


//in order to send a signal to the mobile to off the ringer we still need to use the bandwidth which is already bought by the carrier//
Nope, not true. Do it over Bluetooth, which uses the 2.4 Ghz band, NOT the frequencies used by the phone itself. One of the links is to a vendor doing exactly this.
-- krelnik, Apr 09 2004


That'll work great.

Until people get bored and start installing them .. everywhere.

Or drive around with amplified ones that have nnn-watt amps.

Yeah, that'll redefine wardriving.
-- brianr, Jul 20 2005



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