Mobile Phione - location in emergency.

Mobile Phone location (assuming it doesn't have a GPS built in ) works by measuring its distance from at least 3 base stations. It does this by measuring the time it takes a signal to travel base-mobile-base.

If it's only in range of 2 bases, they can only localise to two possible locations.

If it's only in range of one base station (remote area, deep valley), they can only determine that it's a certain distance from the base.

If the mobile is switched off then nothing happens.

I really have to wonder about this techology though, I was in a weak signal area 30km north of Sydney and it told me I was near Melbourne !!!!! That was using a Bluetick NextG phone.

And to save an obvious question - there is NO mobile phone that can send or receive to satellites, unless it is a satphone.

If you're out of range for your network provider, the phone can put through emergency calls on any accessible network USING THE SAME BAND. e.g if you are on Vodaphone GSM and out of Vodaphone range, you can connect to Optus or Telstra towers for 000 or 112 calls, as they have GSM. It's technically impossible to connect to Telstra NextG-only base stations.

If you're out of range for 000/112, then you're out of range for anything.

Firstly a mobile phone that is switched off or has a flat battery cannot make calls (obviously) or be located by the phone providers as it needs power to poll an aerial. The other part of your question is correct, a mobile phone that is turned on can be tracked by the phone companies/police.

The way it works is that a mobile phone is constantly polling for the nearest phone tower/aerial thus is in communications with the phone provider nearly all the time. Even if your phone is not in range of your provider, it may be in range of another provider and will actually communicate with them (although you wont see that as you would not subscribe to that particular provider).

The fact that your mobile can communicate with any/all providers then allows any mobile phone to call 000 even if not in range with your provider. All mobile providers allow 000 calls from any mobile.

Hope that helps :)

1. No, phone needs to be on.

2. No, ditto

3. No such number. If you are out of range, that's it.

cheers

A little off topic but some time ago some lost bush walkers were located by sending photos of the surrounding hills to rescuers.

One of the locals who was familiar with the area could identify the hills from the photos and map a location for the lost walkers.

It saved a lot of time on a ground search.

There are mobile phone detectors existing that will detect mobile phones that are switched off but the battery does need to be on the phone and they only have a very limited range (metres) The technology is cost prohibitive and totally unusable for search and rescue. It is more for scanning purposes in high security installations. Even the 'must be switched on" mobile phone detectors are worth a tidy sum really. Location over distance is as described in above replies by utilising the received signal through networks as the phone updates with towers.
Just a bit of trivia