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The Vision for Next Generation 911 (NENA i3)

Learn more about the i3 Standard for Next Generation 9-1-1.

Since its beginnings in 1967, 911 has been linked to traditional telephone technology. Basic 911 provided calling to a local law enforcement dispatch center by using direct trunking from the telephone company’s central office to the center. Basic 911 was eventually able to provide the caller ID and sometimes location, but virtually all other information was communicated by voice from the call-maker to the call-taker.

Then, with the mass adoption of cell phone technology in the late 1990s and early 2000s came Enhanced 911 (E911). The major difference between Basic and E911 is that E911 used a Selective Router and the caller’s location to determine which PSAP to route the caller.

In the early 2000s, the National Emergency Number Association (NENA) began a nationwide discussion between 911 Authorities, Public Safety Answering Points (PSAPs) and 911 Call Handling System vendors about what the future of 911 would look like. This conversation resulted in what is today known as the Next Generation 911 i3 standard. This standard, at it’s simplest interpretation moves from traditional analog technology to a fully digital solution. A more in-depth analysis of NG911 reveals the following components, features, and functions:

  • Emergency Services IP Network (ESInet) used to connect the carriers to the PSAPs.
  • Border Control Function (BCF) also known as a Session Border Controller, this device provides security to the 911 core while still allowing calls to enter and be delivered to the appropriate PSAP.
  • Emergency Call Routing Function (ECRF) is a process that uses location protocols and geographic data to plot the location of the 911 caller and determine the uniform resource identifier (URI) for the appropriate PSAP as well as responders (Law, Fire, and EMS) for that location.
  • Location Validation Function (LVF) is essentially a copy of the ECRF data that is used by telecommunications service providers to validate a customer’s civic address at the time services are sold.
  • Emergency Services Routing Proxy (ESRP) is a digital proxy server that selects the next-hop routing within the ESInet based on the location of the caller and policies created by the PSAP to control call delivery.
  • The Policy Store contains rules for call routing depending on metadata associated with the digital call for service. For instance, a PSAP may create a Maintenance Policy that reroutes calls on a specific day at a specific time to another PSAP so that maintenance may be performed on the call handling equipment. Such policies are referred to as Policy Routing Rules (PRR) and associated with the Policy Routing Function (PRF).
  • A Bridge is a service provided inside the Next Generation Core that allows two or more PSAPs to participate in a call simultaneously. The Bridge function is also used to perform transfers from one PSAP to another.


ESInet Implementation

Between 2016 and 2019, the State of Washington Emergency Communications Office (SECO) worked with contractors, carriers and the 911 call-taking community to implement a fully modernized digital 911 Emergency Services IP Network (ESInet) that uses MPLS (Multiprotocol Label Switching) routing technology to deliver calls for service quickly and efficiently. The WA ESInet is complemented by the NENA i3-compliant Next-Gen Core Services functions used to determine a caller’s location, identify the correct Public Safety Answering Point, and deliver the call for service with the caller’s location information.

FCC Report & Order Implementing NG911

In June 2024, the Federal Communications Commission released a report and order describing steps toward implementing next generation 911 services nationwide. This action enhances the already advanced deployment of 911 services in Washington state.

In May 2025, the SECO will begin notifying the wireline, wireless and VoIP carriers in the state of their intention to implement Phase 1 of the FCC Report & Order — which requires carriers to connect to the ESInet using the fully digital Session Initiated Protocol (SIP) telecommunications technology. Depending on a carrier’s classification by the FCC, they will have either six or 12 months to complete this transition to SIP from the traditional TDM technology. The SECO seeks to be a good partner during this transition and establish points of connection as close to the carrier’s switching equipment as is feasible.

Phase 1

Phase 2