![](templates/subSilver/images/full_size.gif) Poster: A snowHead
|
A study by mobilkom austria points to high awareness of the life-saving value of mobile phones when skiers, climbers and hikers head for the mountains. 92% of residents of Lower Austria are aware of the mobile phone's life-saving value in dangerous situations, with 90% of Vorarlberg residents saying the same.
This report from cellular-news.
An Australian skier was led to safety with the help of his mobile last weekend. The 28-year-old lost his way 5km from the resort of Thredbo, but received instructions from the local ski patrol.
This report from ABC News Online.
Anyone have any personal experience of using a mobile in a white-out, or when otherwise lost or injured?
|
|
|
|
|
![](templates/subSilver/images/full_size.gif) Obviously A snowHead isn't a real person
Obviously A snowHead isn't a real person
|
We were called on our mobile by the Ski School in Courchevel to tell us our 7 year old daughter had had her leg broken when her class was hit by an adult skier. We had just got to the outskirts of Les Menuire!
That was 6 years ago but the memory is still so vivid! The parents amongst you will understand what we went through
|
|
|
|
|
![](templates/subSilver/images/full_size.gif) Well, the person's real but it's just a made up name, see?
Well, the person's real but it's just a made up name, see?
|
The flipside being that current theory seems to be that phones can interfere with the signals of avalanche transceivers. It's best to keep your phone off and away from the transceiver. Obviously, you can switch it on should the need arise.
|
|
|
|
|
![](templates/subSilver/images/full_size.gif) You need to Login to know who's really who.
You need to Login to know who's really who.
|
Arno, that's most interesting. Do transceiver manufacturers (or phone manufacturers) warn users of that possible danger?
|
|
|
|
|
![](templates/subSilver/images/full_size.gif) Anyway, snowHeads is much more fun if you do.
Anyway, snowHeads is much more fun if you do.
|
David Goldsmith, not that I know of, but all the guides I had this year told me about it. It wasn't obvious they were all switching theirs off though!
|
|
|
|
|
![](templates/subSilver/images/full_size.gif) You'll need to Register first of course.
You'll need to Register first of course.
|
David Goldsmith, I'm not sure how scientifically this has been tested, but, as GrahamN says, it is common teaching among mountain guides. As far as I can tell, the interference wouldn't result in a total failure of the transceiver. Rather, it might distort the signal and make it slightly less accurate. But when you've got 15mins maximum to dig someone out, you want all the accuracy you can get!
A quick scan of the Ortovox website didn't reveal anything about this.
|
|
|
|
|
|
|
|
|
David Goldsmith wrote: |
Do transceiver manufacturers (or phone manufacturers) warn users of that possible danger? |
DTS do in their instructions for their 'Tracker' model. They say that mobiles must be turned off.
I was also impressed with our guide in La Rosiere in that we had to prove to him that our mobile phones were turned off before we went off piste.
|
|
|
|
|
![](templates/subSilver/images/full_size.gif) You'll get to see more forums and be part of the best ski club on the net.
You'll get to see more forums and be part of the best ski club on the net.
|
Arno, I would be interested to know just how a mobile phone can interfere with a radio that is transmitting/receiving in a band that is many megahertz away from the band in which the mobile works! As far as I recall Avalanche transceivers operate in the hundreds of Kiloherz range, whereas mobiles operate somewhere between 900MHz and 1800 / 1900MHz. This is especially true when you consider that a mobile phone is only active for about 20 milliseconds every 2 to 5 seconds. The rest of time it is amost totally inert and runs off a 32KHz sleep clock (which is why you get 200 hours of standby from a GSM mobile)! Even when it is not asleep it doesn't in fact transmit anything at all unless it is actively involved in a conversation, or once an hour (or thereabouts) performs a location update to tell the network that it is still alive.
I have my doubts about this story!
|
|
|
|
|
|
Mike Lawrie, try sticking a mobile phone next to a monitor or speaker. The problem isn't actual interference on the frequency, but interference to electromagnetic equipment. Or so I'd guess. Why do you think you switch a mobile phone off on an aircraft flight? Because it can cause enough interference to fook up navigation aids.
|
|
|
|
|
![](templates/subSilver/images/full_size.gif) snowHeads are a friendly bunch.
snowHeads are a friendly bunch.
|
mark_s, you will only hear anything if the mobile is actively engaged in a call! Otherwise you won't hear a thing. The point about flight equipment is worth making, but in fact after years of having everybody switch their mobiles off the airlines have now realised that the mobiles don't have any measurable effect on their navigation equipment at all and the rule is about to be dropped!
This may or may not have something to do with the fact that the airlines are about to install GSM base stations on board which will allow you to be reachable via satellite link as you wing your way across the world. I certainly hope the service is unreasonably expensive, because about the last thing I want is to spend my flying time being reached by the office!
|
|
|
|
|
![](templates/subSilver/images/full_size.gif) And love to help out and answer questions and of course, read each other's snow reports.
And love to help out and answer questions and of course, read each other's snow reports.
|
mark_s wrote: |
Mike Lawrie, try sticking a mobile phone next to a monitor or speaker. The problem isn't actual interference on the frequency, but interference to electromagnetic equipment. Or so I'd guess. Why do you think you switch a mobile phone off on an aircraft flight? Because it can cause enough interference to fook up navigation aids. |
Nothing to do with navaids, it's more to do with the way the cells interact with the phone and the Telco's methods of detecting cloned phones.
A typical phone in a typical situation will be in contact with several base stations (cells) but will be 'local' to one of them and use it for transactions. If that phone then sets off moving (like in a car) it will move from cell to cell as it goes as each comes into range.
If that phone is taken up to altitude then it will see many base stations and this confuses the networks no end as you might get a good signal with a base station that's more than a few links away from the preceeding one and this tends to trigger the network's fraud sensors into thinking the phone has been cloned and is in more than one place at the same time.
|
|
|
|
|
|
Mike Lawrie, on an airliner yes. However, if you are in a small aircraft, you should never have your phone on, ever. Think of the effect it has on your TV (and it isn't just when 'actively engaged in a call', it is if is communicating in any way shape or form), and apply to a VOR reciever. Now consider a VOR reciever is much more sensitive than a TV set, and then consider the potential end result.
Now apply this to an avalanche tranciever, which is roughly the same as a VOR reciever, and probably has roughly the same sensitivity. You say there is no possiblity for it to interfere? I beg to differ.
Also correct me if I'm wrong, but the last I checked, mobile phones used low-end microwave frequencies...and microwaves have a different set of properties to radio waves.
On a ligher note, I am leaving the country in a few hours time, so I don't have time to fry my brain over a semi-physics debate
|
|
|
|
|
![](templates/subSilver/images/full_size.gif) You know it makes sense.
|
FenlandSkier, are you trying to tell me that airlines and pilots are so strict about such rules because cellphone networks want them to be? Try telling that to the several million private and commercial pilots who I think will disagree with you...
|
|
|
|
|
![](templates/subSilver/images/full_size.gif) Otherwise you'll just go on seeing the one name:
Otherwise you'll just go on seeing the one name:
|
mark_s, Yes, I am saying it's not to do with the planes but to do with the characteristics of the GSM networks.
The rule is applied to the paying passenger not so much because of the networks but because (in the UK) the CAA rules prohibit the use of mobile phones in flight. For the CAA it's easier to ban something than it is to understand it and find an actual use (look at GPS for primary navigation for example).
Pilots have been known to use mobiles in flight before when conventional radio services have become unserviceable or unreliable.
A quick Google on "Airbus" and "picocells" should bring some facts into the debate rather than relying on my dodgy memory but I think the relevant number s are 25 mile range on a base station and a problem with speeds over 250mph with timing issues.
|
|
|
|
|
![](templates/subSilver/images/full_size.gif) Poster: A snowHead
|
FenlandSkier, GPS as a primary navaid should be banned. Imagine the breed of pilot it would introduce; who rely on GPS and forget how to navigate using conventional navaids, and have severe difficulty when their GPS reciever fails...
And I am of the belief, as are most GA pilots, that mobile phones have the potential to intefere with equipment, and should not be used during flight. Are you trying to say that the majority of GA pilots, plus the CAA, FAA, and other organisations are incorrect?
Anyway, I am going on holiday
|
|
|
|
|
![](templates/subSilver/images/full_size.gif) Obviously A snowHead isn't a real person
Obviously A snowHead isn't a real person
|
Anything has the potential to interfere with other equipment but that isn't what we're debating.
I switch off my mobile on a flight (as would most others) because it's part of the conditions of travel that I do so.
These guys might take issue with the CAA et al, http://www.aviationtoday.com/cgi/av/show_mag.cgi?pub=av&mon=1004&file=racetoallow.htm
http://www.eweek.com/article2/0,1895,1571573,00.asp makes some good points as well, but then I would pick those 2 URLS as they back up my arguement, plenty more anecdotes out there on usenet though including more than a couple from a mobile telecoms engineer (who is also a GA pilot) on uk.rec.aviation.
Enjoy your holiday, I'm not off anywhere now til the PSB not too far off though.
|
|
|
|
|
![](templates/subSilver/images/full_size.gif) Well, the person's real but it's just a made up name, see?
Well, the person's real but it's just a made up name, see?
|
FenlandSkier,
Quote: |
A typical phone in a typical situation will be in contact with several base stations (cells) but will be 'local' to one of them and use it for transactions. If that phone then sets off moving (like in a car) it will move from cell to cell as it goes as each comes into range.
If that phone is taken up to altitude then it will see many base stations and this confuses the networks no end as you might get a good signal with a base station that's more than a few links away from the preceeding one and this tends to trigger the network's fraud sensors into thinking the phone has been cloned and is in more than one place at the same time. |
Not sure how that would work. A GSM phone will only scan for and find those cells which are on the neighbour list of the cell on which it is currently camped. So if the phone is at altitude it may be that it can see more cells than when on the ground, but the only ones it can see are those that are the neighbours of the current serving cell. Given that these are the cells that it is supposed to find anyway I'm not sure why the network would decide that the phone had been cloned.
A GSM phone is only ever in direct contact with one base station at a time (i.e ony ever transmits to the serving base station at a time) by the way. In UMTS the situation is a bit different, and a UMTS phone can receive from a number of cells simultaneously, and likewise a number of base stations will receive it's transmissins at the same time, but only when it's engaged on a call. They do that when doing soft handover from one base station to another. Avoids the break in reception, with resulting click, that you get during a GSM handover.
|
|
|
|
|
![](templates/subSilver/images/full_size.gif) You need to Login to know who's really who.
You need to Login to know who's really who.
|
Don't worry, once we have all moved (bought) to 3g Mobile satellite is the next 'big thing' apparently
|
|
|
|
|
![](templates/subSilver/images/full_size.gif) Anyway, snowHeads is much more fun if you do.
Anyway, snowHeads is much more fun if you do.
|
Mike Lawrie, no idea whether the science of this is any good or not. i do know that most of the time a mobile is no use to you if you are buried because you won't be able to move to use it. so i'd rather not take any chances on the piece of equipment which may save me
|
|
|
|
|
|