I feel I ought to know the answer to this one, but I do not.
My household here in the US does not have a landline. We use a cell phone for everything. What happens if I call 911. Years ago, I recall this being an issue, but I presume it has been sorted out by now.
If you call 911 on a cell phone, you get 911. Even if your cell phone doesn’t have service.
Do I get some local 911? Do they know my address automatically?
All 911 is local, AFAIK. They know your address, but probably not very accurately, by the cell towers you are connecting with, and GPS on your phone, if it has it.
Don’t know how that works in Qatar. 
Where I live (Milwaukee County) I get the Sheriff’s office. What that means is that if I’m not in calling about a problem on the freeway/airport the first thing I say is “Hi, can you please transfer me to [suburb]”. What pisses me off is when the 911 operator says “Sir, I asked you what your emergency is” and I have to say “Well, I just saw a really bad car accident on the corner of Pennsylvania and Grange” and they say “Okay, I’ll transfer you to Cudahy”… and I think to myself ‘yeah, that’s why I started out with “can you transfer me to Cudahy”’
I know, they’re just doing they’re job, but I’ve talked to enough really, really ignorant jerkish 911 operators over the years that when I call and ask to be transferred somewhere I wish they would just do it instead of wasting time making me explain everything twice.
The cell phone company can track you to a particular cell area if they really put their minds to it (and can probably triangulate a bit to get a more accurate location), but chances are the 911 operator doesn’t know where you are, and probably won’t be able to get the cell phone company involved in a timely manner.
Some of the newer 911 systems can use GPS information from your phone (if your phone has GPS) which will get them a bit closer to you, down to the accuracy of the phone’s GPS capabilities. A lot of 911 systems don’t have this capability yet though.
Thank you all.
They don’t need to put their minds to it. They know which tower you are affiliated with and have that tower’s ID already recorded in their database. Additionally, most, if not all, cell phones sold in the US in the last several years have been required to have E911 Phase 2 capabilities-- This part of the reason why it’s almost impossible to get Verizon to activate a phone nowadays that doesn’t have GPS.
You might want to register your cellphone number with the local public safety authority in case they need to contact you via the Reverse 911, in case of something that affects your area. I’ve gotten such calls when there was a noxious fire or other local emergency.
Not all 911 is local.
It use to be that a 911 callI in the central Coast area of California was answered by CHP 911 in Valejo Ca. In the last year or so the system was updated. With a 911 call the system determines which cell tower you are bouncing off. If it is not near any highway it is forwarded to the local 911.
Something else that’s good to know: you can, indeed, call 911 from any charged-up cell phone even if you don’t have service, but if you get cut off they won’t be able to call back. You have to call them back.
Didn’t someone say here that even with cellphones with GPS in a dense urban area it might not be enough to narrow it down to an individual residence, especially if it’s a duplex or condo or something?
Here is wiki on E911:
http://en.wikipedia.org/wiki/Enhanced_9-1-1#Wireless_enhanced_911
Note that the phone company is only required to report your location with 300 meters. GPS can do better, but you won’t necessarily get a GPS fix indoors. I’d suggest telling the 911 operator exactly where you at first thing and the nature of your emergency second.
Please note if you are calling VOIP, you might be SOL. This is something you probably should find out before you need it.
Remember that a particular cell tower can receive radio signals from many municipalities. A tower near a city border can receive calls from the city, a handful of suburbs, and unincorporated areas, all of which have different 911 dispatch centers.
One of the most annoying problems for landline phone companies is routing 911 calls to the right dispatch center. Given municipal boundaries, central office boundaries, and even postal boundaries that can change over short distances (and over time), it does take a lot of effort to get the calls to the right 911 center. For example, there is a short stretch of Foster Avenue in Chicago (between the Des Plaines river and O’Hare) that is inside the Chicago municipal boundary, has Rosemont Zip Codes, and Schiller Park phone exchanges. Just going by CO boundaries or even by Zip Codes would get you the wrong 911 center.
Do you know that for a fact? In my county, all 14 municipalities and several unincorporated areas are handled by the county’s single 911 service.
Cook County (where most of Chicago is located) has a small 911 center that serves unincorporated areas in the county and seven small and/or destitute municipalities. The City of Chicago has its own 911 center. Other municipalities either join together to operate their 911 centers or operate their own 911 centers.
Even if that is not the case where you live, a tower near a county border can handle calls from different counties. A tower near a state line can handle calls from different states.
My area has an additional wrinkle, and I wonder how that works. Due to the geography and the water, sometimes a cellphone call is handled from a tower across the water 10-60 miles or more instead of the nearest one only a mile or two away. (That’s because the cliffs block the close one and the straight sight line over water has a stronger signal.)
This means that the 911 center you connect to may be not only in a different town or county, or even a different state, and sometimes 600 miles away by road (around the lake or bay). I hope they have an easy way to reroute calls like these.
I’d bet that what you remember was an issue with 911 service for VoIP phone service instead of cell phones. I’ve had VoIP service instead of a landline for about ten years now, and you have to let the VoIP service provider know where you are, so that your 911 call can be routed correctly. If you get your VoIP service through your cable company or traditional phone company, they’ll already know where you are, but I’ve had Packet8, Vonage, and now TMobile, and all that it’s possible to tell is that I’m somewhere in the world with an Internet connection.
Here is how it works where I work. We do not have a county-wide dispatch. Each town has their own. When a 911 call comes in from a cell it gets routed through a tower and sent to the nearest dispatcher. They get an approximate location. In areas near borders the calls often are often sent to the wrong dispatch and have to be transferred. Unlike when we get 911 hang ups from land lines, we do not investigate hang ups from cells. Just no way to track it down.