Cellphone 911 Is Crappy At Locating You

If you’re calling 911 from your house, use your land-line. If you don’t have one, be prepared to give your address or location to the 911 operator. Why? From USA Today:

Owing to limitations in Emergency-911 technology, the dispatcher probably won’t be able to pinpoint your location. Unless you can get to a pay phone — not an option in this case — you’ll probably have to give the dispatcher detailed information about your location so emergency personnel can find you.

“Just because you dial 911 on your cellphone, the call-taker doesn’t necessarily know where you are,” warns Bob Gurss, director of legal and government affairs for the Association of Public-Safety Communications Officials (APCO.)

How well 911 locating works depends on what type of cell phone you have and where you are.

There are two types of systems for wireless 911 access: network-based and GPS (Global Positioning System). Network-based systems use multiple cell sites to get a fix on a caller’s location. GPS systems work off chips in cellphones and determine location from a constellation of low-orbiting satellites. Both have pluses and minuses.

Network-based systems tend to work better in urban areas where cell sites are plentiful. They are less reliable in rural areas, where one site may cover many square miles.

GPS is the opposite. Because it relies on satellite signals, it can be highly accurate in open areas. But it’s less reliable in urban settings where buildings and other structures can block satellite signals. Weather also can be an issue.

Verizon Wireless, which uses GPS, “works dead-on” in rural areas, says spokesman Jim Gerace.

“But if you’re (calling 911) indoors, we suggest customers get close to the window” to improve GPS performance, says Fran Malnati, an executive director.

In short:

Cingular and Tmobile: Good in cities. Bad in rural areas. Really bad. Possibly only able to “pinpoint” you within a 5 mile radius.
Verizon and Everyone Else: Good in the middle of nowhere or outside. Bad in cities.

FCC Chairman Kevin Martin is in favor of tightening the rules about how wireless companies are required to report their 911 performance. Currently, they only have to calculate their coverage on a nationwide basis and will not share statistics about local performance. —MEGHANN MARCO

Growing wireless use highlights limitations of 911 [USAToday]


Edit Your Comment

  1. Veign says:

    Even if you don’t have a land line account you can still plug a phone into a jack and get 911. So buy a cheap phone so you can at least get 911 in a pinch…

  2. ptkdude says:

    One comment about the GPS-based location system: it is not “normal” GPS like an auto navigation system. The phone only receives GPS signals from one or two GPS satellites (normal GPS units use at least 3). This information is then combined with location information from the cell site the phone is currently using to determine actual location.

  3. kerry says:

    @Veign: That’s very good advice. One of my friends ditched his landline a couple years ago, I’ll pass this on to him. It’s always worried me that he won’t get real 911 service at home from his cell phone.

  4. Hawkins says:

    Dear me, it seems awfully naive to think that the 911 operator would be able to tell where you and your mobile radio transmitter were physically located.

    I don’t how they have the network rigged up. In real life, this kind of stuff is not reliable.

    On the other hand, if you’ve ditched your landline, and need to call 911 from home, it’s highly likely that you’ll be able to give the operator your address, even under stressful conditions.

  5. wobudong says:

    Verizon Wireless uses CDMA. Most other US wireless systems use GPS.

  6. anexkahn says:

    “Even if you don’t have a land line account you can still plug a phone into a jack and get 911. So buy a cheap phone so you can at least get 911 in a pinch…”

    Not entirely true anymore. You have to have a “soft” dialtone, the higher pitched sounding one that will let you call the telco’s business office, and many times they are disconnecting that now.

    And secondly, due to liability of sending calls without accurate subscriber information, many central offices are no longer routing calls from soft dial to 9-1-1 centers. Questions about: Do they send the old subscriber address? How can you gaurentee the accuracy of that address when the account no longer exists? etc. have made them stop sending those calls through in many areas.

  7. medalian1 says:

    As of two months ago (when I quit) Florida Highway Patrol had no way to locate callers. We didn’t even have caller ID, what a sad operation.

  8. “Unless you can get to a pay phone”

    I recently read a report on telcos removing pay phones as they break rather than repair them since public phones are becoming less profitable.

    Since reading that I have started noticing the lack of public phones in my area.

  9. Josh Smith says:

    Not to mention if the 911 center your call gets routed to doesn’t have the software, anything the phone companies do is wasted.

  10. Snakeophelia says:

    We ditched our landline a couple of years ago, and I spoke with my local PD about it. They suggested that I dial 911 from our cell phone in the house as a test (the detective gave me his name so I could say that he gave me permission). We live on the very of edge of, but not in, Philadelphia, and our concern was that we did NOT want our 911 calls to bounce to a Philadelphia dispatcher! Luckily, it works fine in our area, and we’ve since had to dial 911 and have gotten our local dispatcher, no problem.

  11. FLConsumer says:

    @Veign: Depends where you’re at. Verizon is furiously trying to disconnect (and remove) all phone wiring which isn’t active in this area. Mainly because they’re obligated to maintain it if it’s connected to the building.

    @wobudong: Verizon, SprintPCS, Alltel, and US Cellular use CDMA. Cingular/T-Mobile/Cricket use GSM, not GPS.

    Also, the GPS on many of these phones isn’t actually GPS as we think of it. Instead, many of the phones depend upon the location of towers and try to guess where they’re at based upon the number of towers they “see” and signal strengths & timing. I wish they’d put a full-fledged GPS unit in these phones with some mapping software. Not the watered-down stuff we see today. That’d be probably one of the most useful features they could add to one and one I’d pay for. Google Earth + GPS on my PDA is awesome.

  12. shdwsclan says:

    Actually, CDMA is dominant overall in GPS. It may not work with satellite but the idea is similar.

    Your basically sending data back and fourth between multiple towers which makes it possible to triangulate your position.
    Antenna segment in subways should work the same way with cdma.

    Overall, cdma has dominant coverage by technological definition and implementation versus TDMA[gsm]

  13. oldhat says:

    Golly, why can’t we just let the free market decide this? Obviously the companies have public safety as their first priority here and will do what it takes to make it happen.


  14. pearlandopal says:

    The one time I’ve had to call 911 from home (God, I hope I never have to again), was when my husband randomly and permanently developed a seizure disorder. We have no landline, and it never occurred to me that I wouldn’t have to give my address. No idea whether the call center I got was a local one, but they were prompt and didn’t have any trouble getting an ambulance from the local hospital.

    Actually, that was his second seizure. When the first one happened we’d been at a friend’s house and the 911 call was made from there (from a landline, I assume, although I was too panicked to remember). Interesting anecdote – the friend lives in a very small town, and apparently if a call is made that might require more than one EMT they send both an ambulance AND a fire truck. My husband is not small, and was not in good shape after the seizure, so there were three EMTs plus me and the friend trying to get him down four flights of stairs and across an icy parking lot to the ambulance, with the fire truck standing by.

  15. Landru says:


    I know that cellphones can dial 911 without being activated, but I am pretty sure that is NOT true of land lines, at least here on the West Coast.

    Also, in California, when you call 911 from your cell phone, it goes to the California Highway Patrol. They then have to look up the number for your local police department and transfer you, which can take a long time. I have the local number for my town programmed in my cell phone, to use instead of 911.

  16. indianaguy says:

    more things that most people already know posted on consumerist
    news @ 11

  17. scoobydoo says:

    I spoke to a 911 operator and paramedic not long ago, and for our area (at least 15 major towns) they have ONE “pap” (public access point, the actual 911 center), they “sometimes” get address information on landline calls but are STILL required to ask for the address. They then patch you through to the corresponding response center. Anywhere in that chain of events they could screw up and put your though to the wrong one.

    They admitted that things are a real mess, and that they won’t be changing any time soon.

  18. jwissick says:

    In the SF Bay area, you are lucky if you can even get anyone to answer the phone when you call 911 on your cell phone. The lines a SO busy that it does not ring or even give a busy signal. If it does ring, you will not talk to a dispacher for at least 4-10 minutes.

    911 is a joke. Anyone who tells you otherwise is a liar.

  19. RonJeremy4Pres says:

    I find it more creepy that they CAN locate your cell phone.

  20. kerry says:

    Of course they’re required to ask for your address, but the idea is that if you’re attacked or become unable to speak to the operator at some point during the call they will be able to ascertain your location based on GPS/cell towers/caller ID and reach you, anyway. The times I’ve had to call 911 I was on a cell phone and had to give them my location (I wasn’t at home), and it’s a little scary to realize that if I was calling because I was being threatened or very ill and lost contact with the operator during the conversation they may not have been able to find me. That said, I just bought a cell phone with real, honest-to-goodness GPS, so maybe I’ll be easier to find than before.

  21. roamer1 says:

    @Veign: This is true in some areas, but not all — in Atlanta, plugging a phone into an inactive phone line gets you nothing.

    @wobudong: CDMA networks (VZW, Sprint, Alltel, etc.) use GPS, as do iDEN networks (Nextel). GSM networks (Cingular, T-Mobile) triangulate using only cell sites.

    @Josh Smith: True.

    @FLConsumer: Cricket is CDMA (just like VZW and Sprint), not GSM. Nextel phones can actually be used as standalone GPS devices in conjunction with a PC or software on the phone.

    @Landru: IMO, the way wireless 911 is done in California is completely broken; it might have been OK back in the late ’80s and early ’90s when most phones were mounted in cars, but not now! In most states, 911 calls from cell phones go to the local jurisdiction, not the state highway patrol. (Most states have a separate number to reach highway patrol, such as *GSP in GA.)

    I’m surprised no one has mentioned 911 and VoIP yet… ;) (Depending on the provider, 911 from VoIP lines is either more or less the same as landline 911 or is a sort of cross between landline 911 and wireless 911.)

  22. Imhotep says:

    Using Verizon, I got a nothing but a busy signal when I dialed 911 3 times! Eventually had to dial 411, and got routed to the local PD. THe 411 operator told me that I got a busy signal because I was “on a wireless phone”. I was like, “WTF good is a cell phone if you can’t use it in an emergency??!”.

    I later called customer service and was told to switch to analog mode, from digital for more reliable 911 service…. luckily haven’t had the opportunity to test it, but I’m worried these cell companies are getting away with false claims of emergency “911-connect” service which doesn’t even work.

  23. anexkahn says:

    There is another interesting part to wireless 9-1-1, and its not a technical problem — its the additional burden placed on PSAP’s (public safety answering point’s), staffing levels. Sometimes it seems that every single person passing a collision scene or other incident feels that they need to dial 9-1-1, even though they may not have relevant information. This creates an enormous burden on dispatchers receiving 20-30+ calls on a simple accident.

    Granted, it’s always better to have more reports of a serious incident than have something life threatening go un-reported, but this is why you are seeing busy signals and call queues showing up more and more on 9-1-1 lines.

    In our jurisdiction, each County is responsible for maintaining it’s PSAP, and they can choose to pair with another county for a centralized, multi-agency PSAP if they wish. The number of trunks (active lines at once) into each PSAP is dictated by the state based on the population that is served by that PSAP.

    the service area is then divided up into geographical sectors. Both wireless (based on tower location) and wireline (based on service address) are put into these sectors. The 9-1-1 lines are then programmed so that any single sector can never fully saturate the available number of trunks going to the PSAP.

    This means that if a house fire, vehicle collision, or some other majorly visible emergency happens in one section of the county and 50 people all try to call in to report it, there is always at least one available trunk into the psap from someone across town to call in a different incident.

  24. ScramDiggyBooBoo says:

    I work for Harris Corporation and we build this one radio (AN/PRC-152, google it) that has GPS built into it. Because GPS is receive only, everytime the “talk” button is pressed, it also sends out data packets that have the coordinates encrypted in that data. The only downfall is that is has to be outdoors. If you go inside, then it relays the last coordinates it has stored before it lost GPS connectivity. I dont know why cell companies cant do something like that. These radios cost like 30 grand a piece, that could by why as well!! They are no bigger than a handheld CB. Even if this same kind of system was implemented, most of the time you would call 911 from your home and the last coordinates would be from what, your front door? Close enough for me. It would be kind of crappy if you were at the Mall of America or something though..