Seek "relay ringer" for mobile phone

Is it possible to get a standalone device which will ring when a call
is receieved by a mobile phone which is 3 or 4 metres away?

I vaguely recall something like this which a person would carry close
to them while their mobile was in their bag or briefcase. I want
something like this but which works over a slightly greater distance.

(Seems to me that such a device might be picking up the transmitted
signal from the handset as it negotiates with the base station for an
incoming call.)

On 07/04/2008 07:29, Foxxo wrote:

> Is it possible to get a standalone device which will ring when a call
> is receieved by a mobile phone which is 3 or 4 metres away?

A bluetooth headset, paired with the phone.

> I vaguely recall something like this which a person would carry close
> to them while their mobile was in their bag or briefcase. I want
> something like this but which works over a slightly greater distance.
>
> (Seems to me that such a device might be picking up the transmitted
> signal from the handset as it negotiates with the base station for an
> incoming call.)

The "lighting up keyrings" parasite power from the aerial but only work
over a few inches, anything else just picking up the phone->basestation
transmissions will get confused by the regular "I'm still alive"
transmissions and by any other phones within your 4m radius.