Guthrie County E911 Office
200 North 5th Street
Guthrie Center, IA 50115

Ph: (641) 747-8320
Fax: (641) 747-8916
envhlth@netins.net

Hrs: 8:00 to 4:30 (M-F)

Guthrie County Main > E911 Resources > Cellular Phones and E911

Cellular Phones and E911
March, 2006


Today it seems that most people have cellular phones and with these being carried all over the landscape they are frequently used to make emergency 911 calls. In the past, this presented a serious problem with emergency personnel finding the caller who oftentimes had no idea where they were.

Everyone has heard stories of car wrecks in a ravine with the cell caller trying to get help and the emergency personnel driving all over the area to locate them. Sometimes they arrived in time and some times they didn’t. As a result, there have been efforts to make cell phone location more reliable.

Initially, this was done by having the signal “triangulate” off several towers. This would give an approximate location, if one was lucky. This method is still used today on phones that do not have GPS technology built into them. So if you have an old cell phone, you may be relying on this method. It is better than nothing but can, at best, only locate to a general area. Oftentimes cell signals can bounce off cell towers that are not the expected ones and thus a bad location is given.

Today, the technology that is being developed is to use a GPS chip that will give a precise location of the caller. Different public safety answering points (PSAPs) are at different levels in having the capability to recognize this information. When it works properly, this will give a very precise location, theoretically within a few hundred feet.

Guthrie County is fully developed with this technology. (It has been relatively recently installed and is still be refined.) When a cell call comes in with a GPS unit in the phone, the map will come up on the screen and a light will flash at the location of the caller. Again, it should be understood that such technology isn’t perfect and errors do occur. It is very beneficial to also be able to explain your location to the dispatcher answering the call.

It is understood that some phones may have the capability to have the GPS chip turned off so it will NOT give the location. You may want to check this to see that if you have such a phone the GPS is active so it will send the signal. You might also want to contact your cell phone company if you have an older phone to determine if it is GPS ready. If it isn’t, you might consider upgrading your cell phone.

Again, using a regular wire telephone line is nearly always the best way to get the best information on your location.