A public-safety answering point (PSAP), sometimes called a public-safety access point, is a type of call center where the public's telephone calls for first responders (such as police, fire department, or emergency medical services/ambulance) are received and handled. It takes calls from any landline, mobile phone line, or VoIP (Voice over Internet Protocol) line. It can also happen that when 112 is dialed in then a logic is implemented by mobile or network operators to route the call to the nearest police station. Such call centers exist in most countries to answer calls to an emergency telephone number. Trained telephone operators are also usually responsible for dispatching these emergency services. Most PSAPs are now capable of caller location for landline calls, and many can handle mobile phone locations as well (sometimes referred to as phase II location), where the mobile phone company has a handset to location system. Some can also use voice broadcasting where outgoing voice mail can be sent to many phone numbers at once, in order to alert people to a local emergency such as a chemical spill.
In Canada and the United States, the county or a large city usually handles this responsibility, and its PSAP is sometimes called a radio room. As a division of a U.S. state, counties are generally bound to provide this and other emergency services even within the municipalities, unless the municipality chooses to opt out and have its own system, sometimes along with a neighboring jurisdiction. If a city operates its own PSAP, but not its own particular emergency service (for example, city police but county fire), it may be necessary to relay the call to the PSAP that does handle that type of call. The U.S. requires caller location capability on the part of all phone companies, including mobile ones, but there is no federal law requiring PSAPs to be able to receive such information.
There are 5,748 primary and secondary PSAPs in the U.S. as of February 2021[1] Personnel working for PSAPs can become voting members of the National Emergency Number Association (NENA). Emergency dispatchers working in PSAPs can become certified with the National Academies of Emergency Dispatch (NAED), and a PSAP can become an IAED Accredited Center of Excellence.[2]
Each PSAP has a 'real' telephone number that is called when the emergency number (911) is dialed. The telecommunications operator is responsible for associating all landline numbers with the most applicable (often the nearest) PSAP, so that when emergency number is dialed, the call is automatically routed to the most suitable PSAP. PSAPs can be subject to changes including new contact information and changing coverage area. Commercial products exist that purport to keep pace with these changes and allow the telecommunications operator to associate numbers with the relevant PSAP based upon their physical address associated with that number.
In other countries, this is the responsibility of other types of local government, and the particular setup of the telephone network dictates how such calls are handled.
There is also now the ability to answer text messages at some PSAPs, which is useful in areas where weak signal strength due to distance from the nearest cell site causes fringe reception, resulting in blocked or dropped calls. Since SMS messages only require an instant to send, a brief peak in radio propagation (such as a sudden favourable shift in multipath phase alignment) is often enough to get a message sent. Text messages are also useful for the deaf or speech disabled, as it does not require a TTY device.[3]
