112 vs 999
in [UK Mobile]
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From: Peter Parry on 22 May 2010 06:58 On Wed, 19 May 2010 04:43:05 -0700 (PDT), Robert Coates <bobkoytc(a)googlemail.com> wrote: >Anyone know for a fact whether what I've been told is truth or >garbage? It is complete garbage. There is no difference between them in the way they are handled or identified. Both set the same "emergency call" flag in the message from the phone to the base station.
From: Whiskers on 22 May 2010 08:24 On 2010-05-21, tony sayer <tony(a)bancom.co.uk> wrote: >>> Ever heard of Triangulation for mobile phones?.. [...] >>[1] I believe sea or mountain rescuers have been known to 'home in' on the >>signal from a mobile phone, once they've got close enough to detect it. >>Using a portable 'base station' is the latest trick in that particular >>book >><http://pistehors.com/news/ski/comments/0985-spooks-gadget-could-revolutionize- >>mountain-rescue/> > > You'd think that people up in the mountains would be rather aware of a > device that could do that in times of distress but then again Joe > Publicke eh;?.. > > >>Even an LED 'camera flash' has helped a rescue >><http://news.bbc.co.uk/1/hi/england/3993325.stm>. In my day, we had whistles. -- -- ^^^^^^^^^^ -- Whiskers -- ~~~~~~~~~~
From: Dennis Ferguson on 24 May 2010 09:17 On 2010-05-22, Jon <spam(a)jonparker.plus.com> wrote: > In article <WbVIn.12978$dh7.12142(a)newsfe13.ams2>, zaz(a)zaz.zaz says... >> It didn't say how this was done but I imagine it must be through GPS. > > Err, no. How do we know this phone had GPS? It was done in the usual > way. For CDMA phones, GPS is the usual way. >> allowing GPS coordinates to be sent when an emergency call is made. > > I very much doubt that's in the GSM standards. It is in the CDMA "standards" though (it is "standards" because one company writes them). >> Unless there were privacy concerns I can't think why this wouldn't have >> been implemented. > > It takes several seconds if you're lucky to get a GPS fix. Sometimes a > minute. And you've got to be outdoors. It's simply not workable. It is assisted GPS. The minute a standalone GPS receiver spends is spent acquiring satellites and downloading almanac information. With CDMA assisted GPS the tower (which has its own GPS receiver and is close to the phone) tells the phone which satellites to listen for and approximately when to listen (i.e. the "acquisition" information), the phone makes the fine timing measurements and returns the raw data, and the network computes the location. The phone will time signals from CDMA towers as well (GPS is CDMA, so timing tower signals is the same process) and send that back too for use when the satellites can't be heard. There's only a fraction of a GPS receiver in the phone, with the network doing the rest, and it's quick since the satellites are "pre-acquired". For CDMA this is easy since everything in the network is synchronized to GPS anyway. For GSM, however, they avoided any reliance on GPS since a lot of GSM countries don't want their telecommunications infrastructure to depend on a facility owned by the US military so this isn't so easy. Dennis Ferguson
From: Peter Whisker on 24 May 2010 16:34 Zaz <zaz(a)zaz.zaz> wrote in news:q8VIn.12977$dh7.646(a)newsfe13.ams2: > On Wed, 19 May 2010 04:43:05 -0700, Robert Coates > <bobkoytc(a)googlemail.com> wrote: >> Anyone know for a fact whether what I've been told is truth or garbage? > > Garbage. The reason for 112's existence is so that all EU member states > have a universal emergency number. It makes no sense at all to have two > emergency numbers work in different ways. > > In the UK and Ireland, 999 and 112 are identical. 112 works across Europe even where they may have a different local number. Peter
From: Theo Markettos on 24 May 2010 17:15
Dennis Ferguson <dcferguson(a)pacbell.net> wrote: > It is assisted GPS. The minute a standalone GPS receiver spends is > spent acquiring satellites and downloading almanac information. With > CDMA assisted GPS the tower (which has its own GPS receiver and is > close to the phone) tells the phone which satellites to listen for > and approximately when to listen (i.e. the "acquisition" information), > the phone makes the fine timing measurements and returns the raw data, > and the network computes the location. The phone will time signals > from CDMA towers as well (GPS is CDMA, so timing tower signals is the > same process) and send that back too for use when the satellites can't be > heard. There's only a fraction of a GPS receiver in the phone, with > the network doing the rest, and it's quick since the satellites are > "pre-acquired". Thanks for that, I didn't realise the network was doing the work. Does this also apply to assisted GPS in (eg) GSM iPhones? Does that mean positioning doesn't work when out of signal range (or on a non-cooperative network)? Theo |