Who to call if an AT hiker goes missing?

[Amanita]

The towers have nothing to do with borders... where did you come up with that? 911 systems and dispatch are extended well past all boundaries. The 911 system here is mounted on many towers and exstends into the next state. If you are referring to cell phone coverage - National system national company. - poor service occurs due to terrain or towers that have been knocked out from storms.

The current phones send a gps location and the smrs make a triangulation and signal strength today. What you may be refering to is the olld analog 900 MHz System that is defunked. See Here

http://searchengineland.com/cell-pho...-the-map-14790

That's all well and good when your cell is actually within range of 3 towers simultaneously, but that's rarely the case up here in VT. Even making a phone call can be hit or miss in the less densely populated parts of VT. It's not surprising that the border with the area near NH has some mix ups. I know at one point on the Long Trail I had to make a call, and ended up putting the phone on speaker and holding it 2 feet above my head while standing on a large rock to get signal.

[4eyedbuzzard]

Ideally, automatically transmitting your GPS info with the 911 call and/or triangularization works to id your location, route the call to the proper 911 operator, etc, but the PSAP and ALI stuff doesn't work ideally - at least it doesn't up here. First, you're lucky to have one tower in range, and there are many areas where even a good GPS can't get a lock on satellites, so my guess would be that a phone's GPS has the same issues. I'm thinking that info simply isn't always available and that there are "holes" in the overall system as well.

[Wise Old Owl]

Well Vermont is one thing and Maine is quite another.... you need to see this. The carriers in your state are working together to put up a few thousand more towers.

http://vtdigger.org/2011/06/27/campb...2013-deadline/

Access to the internet V



For the other nay-sayers - advanced 911 - triangulates and "discovers" and even calls you back if you hang up.

Location is an important concept in the way that the Enhanced 9-1-1 system works. Location determination depends upon the Automatic Location Information (ALI) database which is maintained on behalf of local governments by contracted private third parties generally the Incumbent Local Exchange Carrier (ILEC). The ALI database is used to both route the call to the appropriate PSAP and when the call arrives, the ALI database is used to determine the location of the caller.
A second phase of Enhanced 911 service is to allow a wireless or mobile telephone to be located.
To locate a mobile telephone geographically, there are two general approaches. One is to use some form of radiolocation from the cellular network; the other is to use a Global Positioning System receiver built into the phone itself. Both approaches are described by the Radio resource location services protocol (LCS protocol).
Radiolocation in cellular telephony uses base stations. Most often, this is done through triangulation between radio towers. The location of the caller or handset can be determined several ways:

• Angle of arrival (AOA) requires at least two towers, locating the caller at the point where the lines along the angles from each tower intersect.
• Time difference of arrival (TDOA) works like GPS using multilateration, except that it is the networks that determine the time difference and therefore distance from each tower (as with seismometers).
• Location signature uses "fingerprinting" to store and recall patterns (such as multipath) which mobile phone signals are known to exhibit at different locations in each cell.

[Wise Old Owl]

Ideally, automatically transmitting your GPS info with the 911 call and/or triangularization works to id your location, route the call to the proper 911 operator, etc, but the PSAP and ALI stuff doesn't work ideally - at least it doesn't up here. First, you're lucky to have one tower in range, and there are many areas where even a good GPS can't get a lock on satellites, so my guess would be that a phone's GPS has the same issues. I'm thinking that info simply isn't always available and that there are "holes" in the overall system as well.

Wow, a billion dollar govt. defense system doesn't work? - 4 eye and others please be aware that if you are thinking about something from lets say 5 years ago or ten years ago... the information you have is OLD. My Smartphone recently got a lock in a basement underground with a steel roof. This isn't Magellen 315 or Windows 95. Trees are not a factor as they were in the past as the antennna's for satellites have become more robust and smaller. Signal confusion or not being able to get a lock can still happen in the mountains and around steel skyscrapers.

My phone can get a lock inside my house in 15 seconds. I just tried it.

[Wise Old Owl]

The answer is simple - Ya dial 911. The police arrive and verify, they dispatch SAR and they show up an hour later, they rally a local group to help if needed.

Find fault with that. pull that apart...

As a Amateur Radio Operator that has participated in some of these exercises. (Including the nuclear ones) I have worked in the cell phone industry and have monitored several local search and rescues. - This county has access to dogs, helicoptors, Flir, boats, and loaaaads of people. I can assure you have nothing to worry about.

[Pedaling Fool]

I can assure you have nothing to worry about.

As technology advances that certainly seems to be the case. We have nothing to worry about, which begs the quesiton. Nature is all about balance and to maintain balance it ensures large numbers of organisms die. So why would nature create an animal that with a powerful brain that can figure out ways to reduce hazards posed by nature. The very hazards which are designed to keep our numbers in check.

What other animal our size can approach 7 billion and growing. What happens when we figure out how to extend our biological lifespan.

[4eyedbuzzard]

Wow, a billion dollar govt. defense system doesn't work? - 4 eye and others please be aware that if you are thinking about something from lets say 5 years ago or ten years ago... the information you have is OLD. My Smartphone recently got a lock in a basement underground with a steel roof. This isn't Magellen 315 or Windows 95. Trees are not a factor as they were in the past as the antennna's for satellites have become more robust and smaller. Signal confusion or not being able to get a lock can still happen in the mountains and around steel skyscrapers.
My phone can get a lock inside my house in 15 seconds. I just tried it.

WOO, I'm thinking the AT qualifies as "in the mountains". At least large parts of it.

I made a 911 call in Nov. 2011 on a two year old GPS enabled phone that connected me to VT 911 and I had to tell them twice that I was in Monroe, NH - not Barnet, VT - so that they could route me to Manchester, NH 911 operator to contact NH State Police. Their location data put me over a mile away on the other side of the CT river. Why I don't know. But I do know that the PSAP service is run by private contractors in many areas (at least here it is). They are for profit, have lots of technical and employee issues, etc. Like any business, I doubt they're perfect. ATC and NORAD aren't the guys tracking my phone (well, maybe they are, but that's a different converstation).

Add that from a practical point, when it comes to actually transmitting that location data, up here there are so many stretches of road and trail and areas that have NO reception of any kind, and I doubt we will ever get 95% coverage. The logistics, money, etc. just don't make it a practical initiative. We all know where most dead zones are and plan our calls and such around them knowing we are going to enter an area of no reception, such as on Rt 302 east of Wells River, VT to Littleton, NH, or around the Thetford to Norwich, VT section of I-91, etc (just two of hundreds of examples within normal driving distances of my house).

But in other news, while GPS is a good example of a gov/defense system that works pretty damn well, just because it's a gov/DOD system doesn't mean much in and of itself. There are lots of multi-billion dollar government systems, defense and other, that don't work as completely "as advertised" and some don't work at all. GPS is likely one of the shining stars, and likely not the norm.

In the end, you still need to be smarter than your phone, though it's becoming increasingly difficult...

[Wise Old Owl]

There we can agree... and that does make sense after looking at the map and you proved the point that the service signals are overlaping boundries.

[Bronk]

Ideally, automatically transmitting your GPS info with the 911 call and/or triangularization works to id your location, route the call to the proper 911 operator, etc, but the PSAP and ALI stuff doesn't work ideally - at least it doesn't up here. First, you're lucky to have one tower in range, and there are many areas where even a good GPS can't get a lock on satellites, so my guess would be that a phone's GPS has the same issues. I'm thinking that info simply isn't always available and that there are "holes" in the overall system as well.

Believe it or not, there are many rural areas that do not even have 911 yet. And there are MANY, MANY places where the 911 PSAP does not have the technology to trace GPS coordinates (often referred to as Phase II 911). Where this technology is available, it doesn't always work. And when it does work, its not 100% accurate. Best case scenario is you're going to be able to plot somebody's location within 100 yards. Many rural areas are just now getting Phase II. Rural areas do not have the funding that big cities do, and they will not have the latest technology...and it is rural areas where we hike.

DO NOT ASSUME THAT JUST BECAUSE YOUR CELL PHONE HAS SOME KIND OF GPS CAPABILTIY THAT YOUR 911 OPERATOR WILL BE ABLE TO ACCESS THIS INFORMATION. IN MANY CASES THEY WILL NOT BE ABLE TO. When you dial 911 you need to be prepared to tell the operator where you are.