Access to 9-1-1 from cell phones is very different from wired phones and also varies greatly around the country.
Basic 9-1-1 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. 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 allows 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 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 county PSAP many miles away, or at a local PSAP, depending on how the wireless 9-1-1 call is routed.
Wireless E9-1-1 Phase I
This 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 callback 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 be 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 9-1-1 rules (according to the FCC), cellular 9-1-1 calls are to be transmitted to the E9-1-1 system and routed to a PSAP regardless of whether they are placed by a cellular service subscriber or a 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.
In our increasingly wireless society, more and more of the public dials 9-1-1 from a mobile device. CTIA-The Wireless Association reported that about 86 million Americans subscribed to wireless telephone service in 1999. Today, that figure has increased to a whopping 302.9 million wireless subscriber connections. In addition, Americans are increasingly cutting the cord: The Centers for Disease Control and Prevention puts the fraction of wireless-only households in the United States at 29.7%. This naturally leads to a significant increase in wireless 9-1-1 calls. According to CTIA, more than 296,000 wireless calls are made to 9-1-1 every day.
Source - http://www.nena.org/
Advanced Location - RapidSOS
The District was an early adopter of RapidSOS location technology. RapidSOS utilizes an advanced location feature built into most Apple and Android devices that allows for much more precise location accuracy than Phase I or Phase II can provide. This can greatly assist in getting first responders to the caller's location much more quickly, especially when the caller may not be familiar with their surroundings.