Major changes in the existing emergency services architecture are being driven by the rapid evolution of the types of devices and services that can be used to call for help. Also there is an increasing volume and diversity of information that can be made available to assist PSAPs and responders in an emergency. NENA recognizes this is a fundamental update to the North American 9-1-1 system, and is addressing the challenge with a system design called Next Generation 9-1-1(?) (NG9-1-1(?)). NG9-1-1 is the evolution of Enhanced 9-1-1 to an all-IP-based emergency communications system. This technical specification, commonly referred to as i3, is the first version of the NG9-1-1 system design.
NENA i3 introduces the concept of an Emergency Services IP network (ESInet), which is designed as an IP-based inter-network (network of networks) shared by all agencies which may be involved in any emergency. The i3 Public Safety Answering Point (PSAP)(?) is capable of receiving IP-based signaling and media for delivery of emergency calls conformant to the i3 standard.
This edition of the i3 standard specifies that all calls enter the ESInet using Session Initiation Protocol (SIP) signaling. The PSAP is selected using the Emergency Call Routing Function (ECRF), and calls are delivered to the PSAP with location and callback information. It further specifies that a Location Validation Function (LVF) must be applied by the origination network to validate location prior to the origination of 9-1-1 calls.
The i3 document references several types of originating networks that could be used to deliver calls to an ESInet, including legacy circuit-switched networks (wireline or wireless). Those must undergo mediation via a gateway to convert the incoming signaling to SIP. In addition, functionality must be applied to legacy emergency calls to acquire location and use the information obtained in call setup signaling to route a call to the PSAP. These originating networks are shown for reference only and are explicitly out of scope for this document.
NG9-1-1(?) encourages the creation of many new coordination and information access services to enrich collaborative interactions between all agencies involved in processing emergency service requests. A Service-Oriented Architecture (SOA) approach has been selected to facilitate the development of those.
This document describes the relationship between NENA standards and standards from other Standards Development Organizations (SDOs) such as the IETF and 3GPP(?)/3GPP2. The application of IMS architecture concepts may appear in the originating network/domain, and as an instance of an IMS-based ESInet. A generic SIP and an IMS-based ESInet are described in this version.
This document is issued as the NENA recommended standard for functions and interfaces between elements within an ESInet. It provides a Stage 2 definition to include 1) interactions between origination networks and the ESInet, 2) functional requirements and their interactions within an ESInet and 3) call delivery to a public safety agency such as a PSAP. The present document also illustrates an example of an i3 physical architecture to provide context for the functional interactions.
| Document | Size |
|---|---|
| Functional & Interface Standards for NG9-1-1 i3.pdf | 1.46 MB |