Michael S. Lorrey wrote:
> The unit could have a kinetic battery that uses a solenoid to
> generate power
> from the movement of the wearer.
Maybe. Current radio systems (based on cell phone tech) would need more power than you could generate this way, but the power requirements are dropping as the technology continues to improve.
> Only if it doesn't have a tolerance built in. Say 5 minutes. The wearer is
> notified when a signal is lost, and they MUST get to a hardwired station
> report their location within that time frame.
I'm picturing a system that sends a brief message at varying intervals (otherwise the energy drain is too large to be practical). Since you don't want the wearer to know when the next transmission is due, there will be times when it gets blocked for perfectly legitimate reasons (subway trips, for instance). Ideally we would like this situation to be handled by some automated system, in order to minimize costs.
The hardwired-station idea would work, but we'd have to build an awful lot of them (probably several hundred thousand just to cover major urban areas in the U.S.), and even then you have to give the wearer enough time to get to one (maybe 10-15 minutes?). Otherwise there will be lots of "false alarms" due to innocuous activity, which will require human attention and thus cost money.
Billy Brown, MCSE+I