scope:

The scope of this standard is to identify and adapt as necessary 3GPP common IMS emergency procedures for applicability in North America to support emergency communications originating from an IMS subscriber (fixed, nomadic², or mobile) and delivering to an Emergency Services IP network (ESInet) or to a legacy Selective Router. The initial version of this standard is limited to voice and Global Text Telephony (GTT) [Ref 3] communication.

While the main focus of this standard is IMS emergency service origination and in particular the associated impacts to an originating device and originating IMS network, the standard also covers related support from the access network and for location acquisition, subscriber home networks in the case of roaming, and considers support for service origination (e.g., call back) from a Public Safety Answering Point (PSAP).

This standard describes the IMS to ESInet interface, as well as the IMS to Selective Router interface.

With respect to 3GPP specifications, the scope of this standard is limited to capabilities defined in Release 10, except where explicitly noted otherwise.

Purpose

The purpose of this standard is to enable deployment in North America of support for emergency services voice and GTT calls in the IP domain from terminals and originating networks that conform to 3GPP IMS specifications. The standard is intended to complement the NENA i3 standard [Ref 100] and to define any changes and limitations to the 3GPP IMS solution that are needed for operation in North America.

² Additional detailed support for nomadic use cases is for further study.