Mobile Phone in an accident

[Patrick Normoyle]

Not if there is no phone coverage in the valley ?

 

 

[Old Koreelah]

Th

 

Not if there is no phone coverage in the valley ?

The track will show flight path and last position. Instamapper leaves a breadcrumb every two minutes. Unless I'm dumb enough to go too low, I should remain in line of sight of a couple of phone towers most of the time.

 

 

[AeroGirl]

PLBs are great, if activated, otherwise totally useless. G force activated PLBs do not have a high success rate of activating, therefore if you do crash, and are unconscious, you cannot rely on it to activate. PLBs also do not leave a breadcrumb of where you have been, so in a situation where you are unconscious, and the PLB did not self activate, you are as good as dead, unfortunately.

 

SPOT on the other hand, if activated to do so before or during flight, will leave a series of breadcrumbs back to SPOTs servers every x minutes. It also has an emergency activation button, which can be activated to alert SPOT in the US that you are in trouble and need help, they will then contact the relevant authorities based on where you are for assistance. In the case where you crash, and are unconscious, it still relies on you to activate it, just like a PLB, but where it differs is that the whole time it has been leaving a series of breadcrumbs, so when authorities are alerted by a loved one, the person with a flight note, or even an expired SAR time, that you have not checked in, they can contact SPOT, and find either the current position of the SPOT (if it is still working post crash), or the last known position and time stamp of the SPOT, thus giving SAR somewhere to start looking, and increasing your chances of being found and thus surviving.

 

SPOT even have a version which you can attach to a mobile phone via Bluetooth and allows you to send a standard text message over the mobile satellite network, in which case if you need help, but are not in danger, eg flat tyre in the middle of nowhere, or out of fuel, and simply need a family member or friend to come and collect you, you can send such a message, including a link to your location.

 

I have no idea why CASA does not allow SPOT as a substitute for a PLB, as in my opinion it is far superior to a PLB, and can greatly increase your chances of survival over a PLB, thanks to the breadcrumbs.

 

Maybe SPOT can create a future version that is also a PLB, thus serving the purpose of both devices.

 

 

[AeroGirl]

Mob phones....even if your in a no coverage area, the Dornier has capability to track your phone via satilite.

I do not believe so, GSM mobile phones work in the 1800 Mhz frequency, and require line of site to work, they do not operate with high enough power for it to be received by a satellite, let alone enough satellites to gain a position fix. An aircraft with 3 GSM antennas could pick up and obtain a fix on the location of the mobile phone by flying overhead.

 

Also AMSA has the ability to call your mobile after you have set off a PLB, also via satilite in no coverage areas..I believe this is still developing technology, and may make your in-plane mob more usefull in future...

Not likely, although an aircraft so equipped with GSM base station equipment could probably call the phone.

 

If you have a Satellite Mobile Phone then they could call you using the Satellite Mobile Phone network, just by calling your the mobile number associated with that Satellite Mobile Phone, they could probably, in theory, also obtain a good fix using multiple Satellites to locate you, but not many people have these, as they are expensive. You can however rent them, which is probably a good idea if you are going remote, no matter what your means of transport. The Satellite Mobile Phone network has coverage all over the earth, with a few very small black spots.

 

BTW, the SPOT Messenger devices make use of the Satellite Mobile Phone network to send packets back to SPOT with your co-ordinates obtain using a built-in GPS receiver, and well as alert SPOT in an emergency.

 

 

[fly_tornado]

Most Australian GSM phones work on either 850 or 900Mhz which is designed for long distance, line of sight applications. 2100Mhz is designed for penetrating buildings. Sending bread crumbs over GSM would work OK as the packets are quiet small.

 

 

[AeroGirl]

Most Australian GSM phones work on either 850 or 900Mhz which is designed for long distance, line of sight applications. 2100Mhz is designed for penetrating buildings. Sending bread crumbs over GSM would work OK as the packets are quiet small.

Yes you are correct in the bands that Australian GSM uses, sorry, but the problem still remains, the distance mobile phones are designed to communicate is up to about 35 km, not the 33,000 km or so required to reach a satellite in orbit. So GSM is quite useless for SAR in remote areas of Australia, even on Telstra. Packet size is never an issue, since we are talking about a few kb of data to transmit co-ordinates and a unique ID.

 

 

[Gibbo]

I used to use a sat phone with gps updates to a website every 10mins. Gave Direction, speed and Altitude and worked every where except nth and south of exmouth. I had real trouble getting reception and a GPS fix from any of the devices carried. I suspect that the US Navy base may have something to do with it.

 

I have had 4 bars of mobile reception with a 4.5db Multi Band antenna plugged into the back of my Phone, pretty much every where in Australia including the most remote deserts as soon as I clear 4500'. Western Queensland is normally about 3000', WA tends to be a little better thanks to the mines. 640kb/s @ 450k east of Alice - Alice tower.

 

 

[Gentreau]

Just to clarify what a mobile phone and the mobile network can and can't do (they are my business).

 

Mobiles in Oz work at 900MHz and the coverage is non continuous especially in the bush.

 

Even when you have coverage, the only normal way that the network operator can locate you, is by identifying the base station that your mobile is talking to.

 

Consider that in rural areas that base station could be up to 70km away (extended cell feature in GSM) and you can see the low accuracy of any 'fix'.

 

If you are fortunate enough to be in a location where you can receive more than one base station, there is special software that the operator can use to try to triangulate you, however that is not running constantly and a trace has to be requested (in some countries by court order) set up and run. That is mostly used in the cases of kidnapping where they are trying to identify the location while talking to the kidnappers. Even when that system is used, the accuracy is highly variable as it relies on estimating distances, not directions, and those distances are the actual radio path from the mobile to the base station. That path may be a reflection off of a building or the side of a valley and not the straight line distance. I have worked on a software solution which attempted to triangulate users in real time and we found it was extraordinarily difficult and not nearly accurate enough to be useful.

 

As for the idea that the SAR plane could find your mobile, that would require that they carry a unit which simulates a GSM network and causes your mobile to try to register with the network. There are multiple reasons why that may or may not work.

 

The only accurate way to locate yourself with a modern mobile is by using the phone's GPS. There are applications, Apples phone finder would be an example, that use the on board GPS to locate the device. The thing about that is that you have to set it up beforehand as you must legally give your explicit permission for the network to trace you. I don't know what particular applications are available as I haven't taken the time to go looking, but the only ones which have a chance of giving your real position are the GPS ones.

 

Hope that helps.

 

.

 

 

[Gentreau]

I have had 4 bars of mobile reception with a 4.5db Multi Band antenna plugged into the back of my Phone, pretty much every where in Australia including the most remote deserts as soon as I clear 4500'. Western Queensland is normally about 3000', WA tends to be a little better thanks to the mines. 640kb/s @ 450k east of Alice - Alice tower.

You may be able to recieve the network, but is it useable ?

 

At 4500' you could be receiving a base station which is too far away to use, even if you have 4 bars.

 

GSM is a digital system and is limited to 35km in normal circumstances, or 70km if the extended cell feature is activated.

 

 

[Gibbo]

Never had a problem. I Was using a Samsung Telstra Next G - 3 years ago now with a Mulitband 4.5db Co-linear with the required adapters and a 30cm x 30cm piece of tin attached to the base to work as a ground plane.

 

Also - WA and QLD railways use Next G as their communications systems so coverage in those states is better than average. I'm still trying to figure out why Optus has coverage in Birdsville and Telstra does'nt.

 

 

[Gentreau]

........I'm still trying to figure out why Optus has coverage in Birdsville and Telstra does'nt.

That could well depend upon their licence conditions and the economics. Networks don't provide coverage for fun. It's there either because it's economically viable or it's a licence requirement.

 

 

[Guest Andys@coffs]

So

 

The australian networks are a bit more complex than that.

 

We have GSM or 2G networks but they are at end of life and only serve those who have a $5 a month service, or as a degraded fallback if 4G or 3G arent available. I dont recall them being extended cell, in fact I think the cells here are pretty small...Australian 3G is indeed the same as 3G in most countries 4G is not truely 4G in a global sense but rather 3.5G. Marketeers in T felt that 4 sounded much better than 3.5 obviously. In teh same way that when 3G was introduced it was called NextG which cant get old like a mere number can.......Perhaps they baulked at EvenNexterG

 

As to frequencies, cant recall the GSM frequencies but seem to recall 900 and 1800mhz. 3G is 850mhz for Telstra and 900Mhz for Optus as the country solution, better range than the 2100mhz that is also allocated mostly in cities. 900 was introduce fairly late in the life of Optus 3G and as such there are probably still stacks of phones out there that cover 2100 but not 900. If thats you, then I really suggest you look to replace your phone. Its been my experience that 900 gives an experience to end users closer to Telstra than 2100 ever can....

 

Not sure about the 4G but needless to say its not the same as anywhere else in the world and hence why Apple in Australia got slapped for calling the iPad 3 4G capable (It is in most other countries but not in Australia......) iPad 4 is Au4G capable as a result of changing the broadband chipsets which now cover more frequencies than most radio scanners........

 

Andy