Cell Phones, VoIP, and 9-1-1

The 911 system was developed during the last 25 years of the 20th century, and it was designed around land lines. Cell phones and IP phone services have given thousands of people new and better access to public safety services, but they also bring new challenges to the 911 infrastructure and to responders.


Accidental Calls

At last estimate, more than 30% of the 911 calls from wireless phones were "pocket dials." At a minimum of 1-2 minutes per call, these accidental calls take up hours of time that could be spent responding to real emergencies. Since we err on the side of sending too much help, accidental calls can also take responder resources.


What You Can Do

Consumers can assist in efforts to eliminate the accidental call problem by following these simple steps:

  • Use your keypad lock feature.
  • Refrain from programming your wireless phone to speed or automatically dial 911.

Location Challenges

"Can’t you just ping my phone?" Maybe. We’ll certainly try if we need to, but GPS location takes valuable time and isn’t always possible. If your call taker keeps pressing you to find a street sign or a house number, this is why.


We can also try to find you by triangulation if your cell phone is in contact with more than one cell tower, or by getting your approximate direction and distance from a cell tower if your cell phone is only in contact with one cell tower. If you’re in a remote location or even in a building where your phone’s GPS doesn’t work, it can be quite difficult or impossible to narrow down your phone’s location to a reasonably-sized area.


Special problems with Internet-based (VoIP) phone services

Many popular phone service providers use internet-based routing for phone calls, including T-Mobile, Comcast/Xfinity,Vonage, Clearwire, and many others. The FCC has identified several issues with using VOIP phones to access emergency services, including emergency calls sometimes being routed to the wrong 911 center if the subscriber moves or is travelling. You can read the FCC’s summary of potential VoIP issues as they relate to 911 service here.



Emergency Notifications and CENS


In circumstances where the public is at risk, such as a hazardous materials incident or a natural disaster, the 9-1-1 Center is responsible for sending out community alerts to all affected citizens. The system is called "Reverse 9-1-1," or CENS, for Community Emergency Notification System. 


These alerts will direct citizens as to the ways they can best stay safe, such as evacuating from a fire or flood, or staying inside and avoiding windows if there is an armed subject in the neighborhood.  These calls are location-based, and will not be sent to mobile phones unless you sign up for them, which you can do here.