Cheap CDMA $49.80 @ Coles pre-paid

hi James,

something people might not know, but if you're out of range on a mobile you can dial 112... "If you are using a mobile phone which is out of range, dial 112. This will connect you directly to emergency services even if you do not have network coverage" Something I only found out about a few weeks ago.

Lyn

Hi Lyn,

I am not convinced that is right.

If the phone can't access network coverage of some type then I don't believe it will work.

112 is a default number for 000 but to access it you still need network cover.

I have heard this before but think better advice is probably to say that digital and CDMA phones will only work in areas of network coverage.

The best remote option is a satphone or HF radio. I think otherwise people may get the wrong idea and try to rely on digital and CDMA phones in areas that don't have coverage and the result could be dangerous.

Not meaning to have a go at you here but I work in this area in QLD emergency services and that is the advice we give.

Hi Brian,

just passing on info given to me, and also what was passed on to parents at the local child care centre. I agree the best thing is to have adequate comms, but found this info "interesting"

:0

Hi,

my understanding is that if you don't have coverage by the network you are with but there is coverage at the location by some other network you can dial 112 and get out on that other network. (eg: if you are with Optus and have no coverage at a particular location with them, but Telstra does cover that region then dialling 112 on your Optus phone will get out on the Telstra network). As I said, just my understanding.

Trevor

Trevor / Casnat is correct. 112 will work even without a SIM card in the handset and it will select the first (or maybe strongest) signal available from any carrier - I don't believe 000 will do that. I'm not sure if 112 works on CDMA but as there is only one CDMA carrier (Telstra) it doesn't matter much.

No mobile phone will work if it cannot obtain network coverage - period.

It's worth knowing that if you are in a marignal signal area for mobiles it is often much easier for an SMS message to get through rather than a voice call. So in an emergency it may be possible to SMS a friend and get them to call 000 on your behalf.

Mike Harding

mike_harding@fastmail.fm

Stand-by to yawn...

112 is only officially supported as part of the GSM protocol, though it is also supported by Hutch & Telstra as part of their CDMA networks.

On CDMA phones, calling 112 is the same as calling 000, which is the same as calling any other number. If it can, it does. If it can't it doesn't. The CDMA protocol doesn't allow for emergency call differentiation or roaming, so if it can get signal all is good. If not, you're stuffed.

On GSM phones, 112 (and 000 by all newer phones) is treated as a different type of call. How different? It automatically and immediately advises the best available cell mast of its urgent requirements, using an abbreviated set-up system separate to a normal call. The cell will then provide priority resources for the call as required - dropping and refusing connection to new calls from non-priority calls if required.

In Australia, calls can be made to 112 (and 000 from most phones) at any time when a phone is switched on *even when your keylock is active * even with no SIM * even when not in home network range * even when call barring or restriction is activated * even when a phone is SIM locked* you get the idea. Don't believe me? As a simple example type 112 with keyguard activated. DON"T PRESS SEND!!

In spite of what some believe, GSM phones cannot roam onto CDMA or satellites or CB or anything else, so no GSM network = no emergency call, whatever you call.

Overseas, 112 is good for priority call handling on every GSM network though acceptance of calls from SIM-less phones may be barred. 3G phones are the same as GSM.

Of course, in time of war or major civil incident a whole new set of priorities come into play on mobile networks. Those of you who work for certain areas of the emergency services have likely registered your mobile to get special infrastructure priority. Mobile network technicians also often aquire this privelege, ostensibly to dial for pizzas during civil emergency ;) Similar rules also applies to most Sat networks.

Yawn over.

Tim

Thanks, Brian, Trevor, Mike and Tim,

I think I'm clearer on the 112 thing...hahahaha...better get me a sat phone I think...:))

cheers

Lyn

Thank you Tim - good and clear explanation.

My question is:
As this is a software only issue, why isn't the network set up to map 000 calls to the 112 handling system and treat both in the same manner?

Mike Harding

Hi Mike,

It's more a handset / SIM firmware issue, specifically around the way the handset sets up and negotiates the call. Have a look at the ACA website where various resources cover the issue of earlier handsets and SIMs. Good for insomnia.

A simple way of putting it is that if the phone / SIM doesn't know that 000 is an emergency call, it can't tell the network as such, or invoke various technical actions to set the call up as emergency, particularly in cross-network and/or congested network scenarios. As a 'normal' call it would be roundly told to p**s off by other networks or even its own, so doesn't even get to tell the mast the number. 112 is always good tho.

The ACA are currently in a quandry about promoting 112 as it doesn't work on landlines in AU, so would create confusion to the masses if told about it in any big campaign. Interestingly (?!) 112 has been integrated in some backbone landline networks abroad, most notably Europe. No idea why AU doesn't do this as fall-back.

Interestingly, a worrying proportion of the AU public think 911 is an emergency number. Why don't we fall-back that also?

Things get murkier if you have a satellite phone as Iridium has no emergency number facility AFAIK. Globalstar has regional compatibility covering 112, 911 and 000 (in AU) I *think* - check before you go nuts. Inmarsat and the like have additional EPIRB facilities I understand, a bit like a 112 call with balls (and location!)

Similarly US networks are required to have [Big Brother] 100m res tracking capabilities for 911 calls by year-end. Most have opted for internal GPS which help the phones call set-up no end (NOT) when you fire off an emergency call. See here here for more if you're into that kinda thing

To bring this back to off-road Australian driving, many upmarket vehicles have on-board emergency systems. Some are even 4x4s. Since they are currently based on the GSM network, they are limited (assume Holden system used 112 system protocol to usurp coverage issues in this article)

I don't even work in telecoms... I should get out more. Anyone need a car-loving telco-geek ;)

Tim

Hi Tim

Again thanks for taking the time to reply in interesting detail.

>It's more a handset / SIM firmware issue, specifically around
>the way the handset sets up and negotiates the call.

So why, I wonder, didn't the ACA insist on Oz handsets mapping 000 to 112? Wouldn't be a difficult firmware option for Nokia etc. even though they wouldn't want to. Can a GSM handset identify the country it's operating in? Which would make it even easier.

>Have a look at the ACA website where various resources cover
>the issue of earlier handsets and SIMs. Good for insomnia.

I try and avoid the ACA website slightly more eagerly than being hit on the head with a lump of wood :)

Mike Harding

Hi,

The 112 dial applies to GSM phones only and what it actually means is when you are out of range with YOUR carrier, i.e vodaphone or optus, and there is another service provider like Telstra giving coverage, THEN when u dial 112 your phone will use the telstra network even though you are not a subscriber.
It would of course work the other way round too... but I think if Telstra does not work out in the sticks somewhere, then you have "Buckley's" trying to get another network.

Cheers

Yep round my neck of the woods anything other than cdma is good for telling the time with only, Kind of makes me wonder why people buy gsm and telstra at that coz anything else on ly works in the majour centres