In most areas of
means that when the three-digit number is dialed, the call is delivered across dedicated circuits to a call taker/dispatcher in a local public safety answering point (PSAP), or 9-1-1 center, who answers the call. The emergency and its location are communicated by voice between the caller and the call taker.
Enhanced 9-1-1 or E9-1-1
In areas serviced by E9-1-1 , the call is selectively routed and the local 9-1-1 center has equipment and database information that allow the call taker to see the caller’s phone number and address on a display. This lets them quickly dispatch emergency help, even if the caller is unable to communicate where they are or what is the emergency. However, when 9-1-1 calls are made from wireless phones, the call may not be routed to the most appropriate 9-1-1 center, and the call taker doesn’t receive the callback phone number or the location of the caller. This presents life threatening problems due to lost response time, if callers are unable to speak or don’t know where they are, or if they don’t know their wireless phone callback number and the call is dropped.
There are 3 stages that are referred to in implementing Wireless 9-1-1. The most basic of these, sometimes unofficially called Wireless Phase 0, simply means that when you dial 9-1-1 from your cell phone a call taker at a public safety answering point (PSAP) answers. The call taker may be at a state highway patrol PSAP, at a city or
Wireless E9-1-1 Phase I
is the first step in providing better emergency response service to wireless 9-1-1 callers. When Phase I has been implemented, a wireless 9-1-1 call will come into the PSAP with the wireless phone call back number. This is important in the event the cell phone call is dropped, and may even allow PSAP employees to work with the wireless company to identify the wireless subscriber. However, Phase I still doesn’t help call takers locate emergency victims or callers.
Wireless E9-1-1 Phase II
To locate wireless 9-1-1 callers, Phase II must have been implemented in the area by local 9-1-1 systems and wireless carriers. Phase II allows call takers to receive both the caller’s wireless phone number and their estimated location information.
Required by basic 911 rules (according to the FCC). Cellular 9-1-1 calls are to be transmitted to the E9-1- system and routed to a PSAP regardless of whether being placed by a cellular service subscriber or non-subscriber.
April 1, 1998 or within 6 months of being requested by the PSAP, whichever comes later.
Originally, October 1, 2001. Specific requirements differ for network-based and handset-based solutions.