4 ms·

If you turn the antenna off when not making a call, how would you be able to receive incoming calls?

• AnthonyMouse 13y ago
  Using the existing phone network? Probably not easily. I think the ideal way would be to make the device a passive satellite receiver. Then when a phone call arrives for your device, the satellite broadcasts a message which your device can passively receive which tells it to wake up and get on the cell network. In theory you can do this with cell towers (it's how pagers work -- you may even be able to reuse the existing infrastructure), but in that case you either have to know somehow which tower is in range of the device (which obviously leaks the device's general location) or you have to broadcast on all towers everywhere (which, as wireless bandwidth increases, becomes increasingly practical since the incoming call message would have nearly trivial length).
  • eyko 13y ago
    Then if they get hold of your number, they can ping your phone so that it comes up on the radar, and track you hourly for example.
    • AnthonyMouse 13y ago
      That would be pretty obvious given that it would cause your phone to ring every hour. Also, they could do the same regardless by just calling you.