999 with no signal?

Swiftlegend · 7 Nov 2009 at 21:26

I've always wondered, can u call 999 with no signal? What will happen and how come sometimes you get emergency calls only but not normal calls?

mame · 7 Nov 2009 at 21:27

I think the phone uses any network available

[TW]Fox · 7 Nov 2009 at 21:27

Because emergency calls can be routed across any available network, whereas normal cars can only be routed across networks owned by your operator or whom your operator has a roaming agreement with.

If there is no, say, Vodafone signal on your Vodafone but there is an Orange signal, you can use that to make an emergency call.

chriscpritchard · 7 Nov 2009 at 21:28

yes, you can as it will go through another provider's network (you can even dial 999 on a landline that is not being served), all 999 calls get priority over other traffic and must be able to be made if ANY signal is available, no matter what network/provider.

Swiftlegend · 7 Nov 2009 at 21:29

wow that was answered quickly lol

Samueltastic · 7 Nov 2009 at 21:31

I was allways told if there is no signal to dial 112 which is the same as 999 as 112 would use any network. I dont know why there are two options if 999 does it as well.

westie17 · 7 Nov 2009 at 21:31

I heard there was a number you could put in before 999 and it would be routed to a satellite or something, sounds funny to me because surely a phones signal couldn't go to space?

Ahhh the post above me may be what I am talking about.

Burnsy2023 · 7 Nov 2009 at 21:39

Samueltastic said:
I was allways told if there is no signal to dial 112 which is the same as 999 as 112 would use any network. I dont know why there are two options if 999 does it as well.

112 is the number used across Europe, they are handled in the same way 999 calls are.

muon · 7 Nov 2009 at 21:40

Samueltastic said:
I was allways told if there is no signal to dial 112 which is the same as 999 as 112 would use any network. I dont know why there are two options if 999 does it as well.

112 works anywhere in the world. It is an internationally recognised emergency number. That is why its good to learn.

But most people learn the emergency number of the country they are visiting anyway.

edit:

After some basic research, as Burnsy said, it seems its just a european thing.

edit2:

http://en.wikipedia.org/wiki/1-1-2

Wiki says it also works on any GSM network.

Burnsy2023 · 7 Nov 2009 at 21:40

westie17 said:
I heard there was a number you could put in before 999 and it would be routed to a satellite or something, sounds funny to me because surely a phones signal couldn't go to space?

Err, no. That's just silly. You still need signal from at least one network to make an emergency call.

Gackt · 7 Nov 2009 at 21:43

westie17 said:
I heard there was a number you could put in before 999 and it would be routed to a satellite or something, sounds funny to me because surely a phones signal couldn't go to space?

How could you call other parts of the country/world if it didn't go to space?

J.B · 7 Nov 2009 at 21:51

Gackt said:
How could you call other parts of the country/world if it didn't go to space?

Are you saying that mobile phones normal operation relies on satellites? Satellite phones work like that.

Normal 'cellular' phones work by use of a system of base stations on the ground.

Burnsy2023 · 7 Nov 2009 at 21:53

Gackt said:
How could you call other parts of the country/world if it didn't go to space?

Fibre Optic Cables?

muon · 7 Nov 2009 at 21:54

J.B said:
Are you saying that mobile phones normal operation relies on satellites? Satellite phones work like that.

Normal 'cellular' phones work by use of a system of base stations on the ground.

Surely if I picked up the landline handset and dialled an Australian number, and it travelled via wires it would be too slow?

edit: unless you use fibre optics I suppose

Burnsy2023 · 7 Nov 2009 at 21:54

ghost101 said:
Surely if I picked up the landline handset and dialled an Australian number, and it travelled via wires it would be too slow?

edit: unless you use fibre optics I suppose

Burnsy2023 said:
Fibre Optic Cables?

Speed of light fast enough?

muon · 7 Nov 2009 at 21:55

Burnsy2023 said:
Speed of light fast enough?

It'll have to do for now. That 0.01ms(or whatever) lag is still a pain.

J.B · 7 Nov 2009 at 21:58

ghost101 said:
Surely if I picked up the landline handset and dialled an Australian number, and it travelled via wires it would be too slow?

edit: unless you use fibre optics I suppose

Most would be routed by fibre, but my point is people sometimes think mobile phones talk directly to satellites. They dont.

EDIT:
I remember hearing a story a few years ago (dont know how accurate it is, if at all) that if you rang America obviously there would be a time delay but only a fraction (think the guy said 2%) would be spent travelling the atlantic because its all fibre and across the mainland uses mainly copper. Like I said, not sure how true that is but sounds believable.

muon · 7 Nov 2009 at 22:02

J.B said:
Most would be routed by fibre, but my point is people sometimes think mobile phones talk directly to satellites. They dont.

EDIT:
I remember hearing a story a few years ago (dont know how accurate it is, if at all) that if you rang America obviously there would be a time delay but only a fraction (think the guy said 2%) would be spent travelling the atlantic because its all fibre and across the mainland uses mainly copper. Like I said, not sure how true that is but sounds believable.

Internet ping tests are probably quite good indicators I would have thought. Try pinging an eastern seaboard server and a western one.

edit: I get quite a large difference between New York and San Francisco, but its less than double.

23ms same city, 85ms ny, and 154ms sf

This will probably be skewed by not having to travel by copper in the states since the servers probably have a fibre connection.