Enhanced 911

Emergency response system in North America

Enhanced 911 (E911) is a system used in North America that automatically associates a physical address with the calling party's telephone number. This system is used in emergency communications to provide public safety answering points (PSAPs) with the location of the caller, which is crucial for dispatching emergency services such as police, fire, and emergency medical services.

Overview

Enhanced 911 is an improvement over the basic 911 service, which only provides the call-taker with the caller's phone number. E911 automatically provides the caller's location information, which is essential for rapid response in emergencies where the caller is unable to communicate their location.

Diagram of the 9-1-1 system, illustrating the flow of information from the caller to emergency services.

The E911 system is designed to work with both landline and wireless telephones. For landline phones, the system uses the Automatic Location Identification (ALI) database to match the caller's phone number with their registered address. For wireless phones, the system uses triangulation and GPS technology to determine the caller's location.

History

The concept of Enhanced 911 was developed in response to the limitations of the basic 911 system, which was first introduced in the United States in 1968. As the use of mobile phones increased, the need for a system that could accurately locate wireless callers became apparent. The Federal Communications Commission (FCC) mandated the implementation of E911 for wireless carriers in the late 1990s, leading to widespread adoption of the technology.

Technology

E911 technology involves several components:

• Automatic Number Identification (ANI): This component provides the caller's phone number to the PSAP.
• Automatic Location Identification (ALI): This component provides the caller's location information to the PSAP.
• Selective Routing: This ensures that the call is directed to the appropriate PSAP based on the caller's location.

For wireless calls, E911 uses a combination of network-based and handset-based technologies to determine the caller's location. Network-based solutions use the cell towers to triangulate the caller's position, while handset-based solutions use GPS technology.

Challenges

Despite its advantages, E911 faces several challenges. One major issue is the accuracy of location information for wireless calls, especially in rural or densely populated urban areas. Additionally, the proliferation of VoIP services presents challenges for E911, as these services may not provide accurate location information.

Future Developments

The future of E911 includes the integration of Next Generation 9-1-1 (NG911) technologies, which aim to improve the system's capabilities by incorporating text, video, and data communications. NG911 will allow for more precise location tracking and better communication between PSAPs and emergency responders.

Related pages

• 9-1-1
• Public Safety Answering Point
• Next Generation 9-1-1
• Automatic Location Identification