Dialing 911 not in you cell phone area code

[DCal430]

Nobody even mentioned vehicles or response to a call, until you. This thread is about call completion.

"It is. It will send the dispatch that is nearest to the cell tower you are using for the call."

Is a dispatch not referring to someone who responds to a dispatcher, such as an ambulance

Edit:

I realize now that dispatch refers to the call center, that he was saying the 911 call is sent nearest dispatch center. But this isn't actually correct for my area, since calls are answered by the central dispatch centers for each respected police or sheriff department. These centers may not be closest to the tower. All 911 calls are handled by the police and sheriff departments here, and they answer calls only for those in their service area.

 

[Ichinisan]

Every tower has registered GPS coordinates. E911 knows how to route your call.

 

[GeekDrew]

"It is. It will send the dispatch that is nearest to the cell tower you are using for the call."

Is a dispatch not referring to someone who responds to a dispatcher, such as an ambulance

Edit:

I realize now that dispatch refers to the call center, that he was saying the 911 call is sent nearest dispatch center. But this isn't actually correct for my area, since calls are answered by the central dispatch centers for each respected police or sheriff department. These centers may not be closest to the tower. All 911 calls are handled by the police and sheriff departments here, and they answer calls only for those in their service area.

Unless you live in a test area, it is true in your area. 911 calls are routed to the PSAP assigned to the tower which is controlling your call. The system gives exactly no damns who answers the call or whether or not they're authoritative for you actual, physical, location. It just gets you to what it thinks is the nearest 911 dispatcher - which is based on the tower's assignment.

 

[GeekDrew]

Every tower has registered GPS coordinates. E911 knows how to route your call.

GPS is not considered until after the call is completed. I've heard that some test areas are working on ways to make that statement untrue, but to the best of my knowledge, nobody has actually implemented it yet.

 

[Red Squirrel]

If you are on CDMA we(phone company, as 911 calls us for the info) can only know what sector you're on.

I helped the police with a guy lost in the bush yesterday actually. Had a CDMA phone, I imagine a flip phone or something older that did not have a compass or anything.

Based on what the police told me and what I was seeing on the map where that sector pointed I could pretty much get a general idea of where the guy probably was and if he just keeps walking towards a certain direction he would find the road but the guy was just completely lost with no sense of direction given it was dark and it was just trees. The cops had a general idea of where to search but no GPS coords. TV makes this stuff look super easy but there is more to it in real life.

The HSPA phones can be traced via GPS though so those are safer to be lost with. Most phones now days are HSPA.

 

[DCal430]

Unless you live in a test area, it is true in your area. 911 calls are routed to the PSAP assigned to the tower which is controlling your call. The system gives exactly no damns who answers the call or whether or not they're authoritative for you actual, physical, location. It just gets you to what it thinks is the nearest 911 dispatcher - which is based on the tower's assignment.

So you call and your tower is located in City A, but city A dispatcher is 7 miles a way, while city B is 4 miles a way it will still connect you to City B dispatcher?

 

[Ichinisan]

GPS is not considered until after the call is completed. I've heard that some test areas are working on ways to make that statement untrue, but to the best of my knowledge, nobody has actually implemented it yet.

Not sure what you're saying, but you're probably talking about triangulating the caller's position. That can only be done because the FCC requires that the precise location of every tower is known.

To comply, even the microcell/femtocell devices are not allowed to operate until they have a GPS fix - and that *must* match the address the device is registered to.

 

[jersiq]

Unless you live in a test area, it is true in your area. 911 calls are routed to the PSAP assigned to the tower which is controlling your call. The system gives exactly no damns who answers the call or whether or not they're authoritative for you actual, physical, location. It just gets you to what it thinks is the nearest 911 dispatcher - which is based on the tower's assignment.

Not to be pedantic, but it gets more granular than just the cell tower location. Within each cell site, the individual sectors may route to different PSAP. The control of the outbound dialed number (from the network perspective) can be controlled at a sector granularity. In the Alcatel-Lucent 5ESS for example, this PSAP number is on the FCI form. I had more than one cell site that was served by two different PSAP's depending on which sector you were in.

Sector A --> Some County Sheriff.
Sector B and C --> handled by the town Police Department.

 

[DCal430]

Unless you live in a test area, it is true in your area. 911 calls are routed to the PSAP assigned to the tower which is controlling your call. The system gives exactly no damns who answers the call or whether or not they're authoritative for you actual, physical, location. It just gets you to what it thinks is the nearest 911 dispatcher - which is based on the tower's assignment.

Looks like I am correct, it isn't based on distance. That would make no sense at all. It is based on what service area the tower is in. A tower in the heart of city A has no reason to call City B dispatch center just because it is physically closer, then all calls will always need to be forwarded to City A dispatcher. This wastes valuable time.

 

[ViviTheMage]

It's super location aware in Minnesota, if I call 911 on a major highway it sends me to state patrol dispatch, and if I am in the city it sends me to local PD.

 

[GeekDrew]

So you call and your tower is located in City A, but city A dispatcher is 7 miles a way, while city B is 4 miles a way it will still connect you to City B dispatcher?

No, that's the exact opposite of what I'm saying.

 

[DCal430]

No, that's the exact opposite of what I'm saying.

No it isn't, that is what the other poster said and you said it was correct.

You clearly state it is all about the closest dispatcher to the tower, and I said it isn't. It is about what location the tower is serving. It has nothing to do with distance. Especially when each city only has 1 dispatch center.

 

[GeekDrew]

No it isn't, that is what the other poster said and you said it was correct.

You clearly state it is all about the closest dispatcher to the tower, and I said it isn't. It is about what location the tower is serving. It has nothing to do with distance. Especially when each city only has 1 dispatch center.

Looks like I am correct, it isn't based on distance. That would make no sense at all. It is based on what service area the tower is in. A tower in the heart of city A has no reason to call City B dispatch center just because it is physically closer, then all calls will always need to be forwarded to City A dispatcher. This wastes valuable time.

IN WHICH QUOTE EXACTLY do you think I said that? When exactly did I say anything about the cell towers picking the dispatch center physically closest to the caller?

Oh, you're probably referring to this:

It just gets you to what it thinks is the nearest 911 dispatcher - which is based on the tower's assignment.

Yeah, the second part of that sentence means that it is not taking into consideration the distance of the dispatch center, and that it's explicitly assigned. :|

Not to be pedantic, but it gets more granular than just the cell tower location. Within each cell site, the individual sectors may route to different PSAP. The control of the outbound dialed number (from the network perspective) can be controlled at a sector granularity. In the Alcatel-Lucent 5ESS for example, this PSAP number is on the FCI form. I had more than one cell site that was served by two different PSAP's depending on which sector you were in.

Sector A --> Some County Sheriff.
Sector B and C --> handled by the town Police Department.

I knew that this is possible, but is it actually commonly implemented? My PSAPs and I can find no evidence that it's used in our area, and a couple of our vendors told me that seems to be the case in most areas.

And yes, it leads to *tremendous* quantities of calls being delivered to the wrong PSAP.