Originally Posted by paul sparkes
i take it back then, i have recently been told by someone studying a nursing degree that it can be used when no signal is available.That is what she has been told by her lecturer anyway.
And you didn't think - I wonder how that is possible?
As JK says if for example you are on O2 and there is no O2 coverage but there happens to be EE or Vodafone coverage you CAN use their network to make 999 or 112 calls [any UK bought phone will work with both]. They also can't be located "via satellite". No ordinary phone is able to send data to a satellite. Some phones could be configured to provide GPS data back via a data network (e.g. using "Find my iPhone") this isn't something routinely available to the emergency services. Further, data is usually the first part of the signal to be lost. It is possible (with quite a lot of effort) for the emergency services to try and identify a very rough location for a phone by checking which cell towers it can "see". This is MUCH harder and less accurate than VHF direction finding which is one of the reasons he coastguard discourage people from relying on a phone as the first means of calling for help at sea. In many cases (where you have a weak signal) your phone will only see one cell tower. With no obstructions in the way a phone can "see" towers many miles away. It wouldn't be impossible for this to leave the coasties with an area of 100 sq miles to search!
Just because someone is a lecturer doesn't mean they can't talk pish, or be misunderstood!