scope:

This ATIS Standard applies IP Multimedia Subsystem (IMS) architecture concepts to Next Generation 9-1-1 (NG9-1-1) networks to encompass:

• Definition of an IMS-based NG9-1-1 Emergency Services Network architecture and set of additional gateway functional elements that are integrated into this IMS-based NG9-1-1 Service Architecture, adopted from the existing NENA i3 architecture, to support the delivery of emergency calls to legacy and NG9-1-1/i3 PSAPs.

• NG9-1-1 network deployment scenarios showing an IMS-based NG9-1-1 Service Architecture interconnecting with a variety of originating network and PSAP types, and associated Stage 2/3 call flows.

Purpose

IMS standards for Emergency Services have been under development and enhancement in 3GPP since 3GPP Release 9. However, from a Next Generation Emergency Services (NG9-1-1) network perspective, the IMS architecture only defined Emergency Service call processing for the originating network and has not defined call processing, transport, or delivery of Emergency Service calls by an IMS-based NG9-1-1 Emergency Services Network.

The purpose of this Standard is to define the Stage 2 (architecture) and Stage 3 (protocols) to enable North American deployment of NG9-1-1 emergency services networks that are based upon the 3GPP IMS specifications. This IMS-based NG9-1-1 emergency services network is called IMS-based NG9-1-1 Service Architecture.

This Standard includes the architecture, functional elements, call flows, protocols, and interfaces which were derived from the Stage 1 requirements in ATIS-0500023, "Applying Common IMS to NG9-1-1 Networks" [Ref 26].

Application

The standard applies to requests for emergency services originating from legacy, IMS-based, and generic VoIP originating networks by routing those emergency service requests to the appropriate PSAP. This standard applies to routing voice, text, and multimedia requests.