Peter Parry wrote:
On Sun, 7 Jul 2019 18:42:48 +0100, "NY" wrote:

"Peter Parry" wrote in message
...
For me, a mobile or a cordless phone that I can take with me as I flee
the building is less risky.

Problem with a cordless is that if the RCD trips (which it will as the
fire develops) the phone becomes useless.

Far enough. But a mobile won't suffer from that.

Mobiles give location with varying degrees of accuracy. The basic
service sends the location of the mast being used via a simultaneous
Emergency SMS. This, in remote areas, can encompass a significant
area and in many rural locations is fairly useless. In urban areas
the basic information is quickly enhanced by mast triangulation as the
call is established. Advanced Mobile Location (AML), if available on
your phone operating system, uses GPS and WiFi location data to refine
location more precisely so works well in rural areas. (It works on
Android, not sure about others). Needless to say most emergency
services use different incompatible systems to handle calls. Some use
a data exchange system called EISEC ( Enhanced Information Service for
Emergency Calls) others voice.

I would always use my phone's own GPS, together with an app such as GPS
Status, to give lat/long or OS grid ref, because I know how imprecise the
mobile phone location (triangulation of masts) can be. Our car satnav has a
option (rather obscure menu - need to remind myself where it is) which gives
lat/long and also a sentence describing the location eg "on A64, 1 mile
south west of junction with B1248".

When you call the emergency service at least two operators are
involved. Firstly the BT operated 999 service operator takes the call
and decides which of the 4 services (fire, police, ambulance,
coastguard) to allocate it to. They will contact the appropriate
closest service to the caller and pass any location information they
have. If the local service is busy it will be passed to the next
nearest which may not be much use.

The specific emergency service finds out where you are and what the
problem is and allocates responders.

If you are calling from a fixed line phone they know where you are.
Calling from a mobile the preferred location information is Postcode
because almost everyone knows it (Postcode is used in over 99% of
emergency calls). Failing that address (as in 67 Firtree Lane,
BIggleswade) is preferred.

After that you are in varying degrees of trouble and the chances of
getting the right people to the right place in less than a few days
starts growing. Emergency services are regional and different regions
and different services use different systems.

Police tend to like road name and description, Coastguard like range
and bearing from a prominent point. Some can use lat/long - but which
one? degrees, minutes, and seconds such as 40° 26' 46? N 79° 58' 56?
W,? degrees and decimal minutes, 40° 26.767' N 79° 58.933' W? or
decimal degrees such as 40.446° N 79.982° W. ?

OSGB - but SO 08357 43962 or 308357243962? or 083439?

UTM? 30U 0476779 5770702
MGRS 30UVC76777070

Some ambulance services use the OSGB grid reference - but in the all
number format 308357243962 which is both uncommon and very prone to
transcription errors.

Google maps favours the "plus code" which no one understands "3MP7+FQ
Builth Wells"

By the time you have found an operator who can use what you are giving
them you will probably have had time to rebuild the house never mind
putting the fire out.


That certainly accords with my recent experience of trying to contact
emergency services. I got the distinct impression that the emergency
services consider using the internet to find out *anything* regarding
location as unsporting.

Tim


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