Check out these resources to help you prepare:
- ALERT King County – Sign up to receive public information and notification to help you stay informed about potential threats and hazards in your area.
- King County Emergency Medical Services – Community Programs – Learn about medical programs that can help you prepare for medical issues including early access to 9-1-1, early CPR, and early defibrillation.
- King County Emergency Management – Learn how to prepare for disasters and become a resilient member of your community.
- Text to 9-1-1 is available in King County and many other counties in Washington State. Click here for more information.
How does 9-1-1 know where you are?
How does 9-1-1 know your exact location? The short answer: Most of the time, they don’t. You have to tell them. Especially if you’re calling on a cell phone.
You may have this vision of a 9-1-1 call-taker who answers the phone, takes down the details of your emergency, and then pushes a button and sends an officer to the location that magically appears on the screen. There are instances where something similar to this might be true, but the majority of the time things are a lot more complicated.
What happens after I call 9-1-1?
You’ve been in a car accident, or someone is breaking into your house, or you are facing any number of emergencies that warrant calling 9-1-1. But after you finish dialing, what happens next? How does your call get to the correct 9-1-1 center? How does the call taker on the other end know where to send a response?
Well, that depends. It depends on whether you’re calling from a landline or a cell phone, and it depends on what kind of 9-1-1 infrastructure your local police department has.
When you initially dial 9-1-1, your call is routed to a building called a central office, which houses information that is managed by the telephone carriers. The central office uses your phone number to send your call to the public switched telephone network (PSTN) for delivery to your destination.
Based on the information in what is basically a big spreadsheet, the phone number called from is identified and the correct 9-1-1 center is listed. The PSTN delivers your call to 9-1-1 and also delivers the address associated with your phone number on the spreadsheet to the call-taker.
All of this happens in a matter of seconds, and if your landline is registered to your current address, 9-1-1 should get your exact address every time. They won’t, however, be able to pinpoint your location within your house like the specific room or floor.
Calling 9-1-1 on a cell phone can yield different results. This is because the location information is provided by your cell phone carrier and each carrier uses different technologies and hardware to determine your approximate location. By approximate location, we mean the location derived from your carrier can be within 5 meters or 300+ meters. That’s three or more football fields!
This is why it is critical for you to know your location.
- At NORCOM, we use an add-on technology to help provide us a more precise location – the location of your actual device, as reported by your device. This is the location that you see when you use your cell phone to order an Uber or check your location on Google maps. This technology may be able to pinpoint your location within 15 meters. Great improvement, right? BUT it isn’t available for every device on every call to 9-1-1. So you still need to be ready to provide your exact location to the call-taker every time you call 9-1-1.
What does this mean for me?
Now you know a little bit more about how 9-1-1 works behind the scenes. Though the emergency number industry is always making new strides, and we’re constantly trying to meet citizens where they are in this brave new world of technology, it’s still important to know your location and to communicate it to the 9-1-1 telecommunicator. The fastest way for the call taker to know where you are is for you to tell them.
Any of these technologies can fail. Things to try if your call to 9-1-1 isn’t working:
- Try calling from another phone that is using a different carrier or different technology. If your wireline isn’t working, try using a cell phone and vice versa. If your cell phone isn’t working and you don’t have a wireline, try another cell phone on a different network.
- Try calling the 10-digit emergency number for NORCOM at 425-577-5656.