You can access 9-1-1 from any wireless/cellular telephone equipped to make regular telephone calls. Federal regulation standards, known as “Wireless Phase II,” require specialized technology that helps our telecommunicators pinpoint your location (from within a few feet to a few hundred feet, depending on the terrain, buildings, etc).
While the majority of cellular providers use technology known as Global Positions Systems or "GPS" to locate callers, some carriers use a process known as "network based triangulation,” which measures the distance and time the cellular signal travels to the cell tower. Regardless of the technology used, you must stay online with the 9-1-1 telecommunicator for the location to be received.
The technology that allows emergency call takers to locate a wireless caller is not 100 percent fool-proof. So, if you call using a cell phone, always be aware of your location, and if possible, be alert to unique points of reference you can provide to the 9-1-1 telecommunicator.
Digital Phone Service and 9-1-1
The use of Voice Over Internet Protocol (VoIP) telephone service, otherwise known as “Digital Phone Service,” has grown in popularity for the last several years. The use of these phone systems/networks among both residential and business customers has skyrocketed due to the relatively inexpensive cost of service and typically free long-distance service.
Be aware of these phone differences and ask about 9-1-1 service before you subscribe to digital or internet-based phone service.