Overview of how an IMS Originating Network Interfaces to an E9-1-1 or NG9-1-1 System
|Publication Date:||1 June 2018|
Scope, Purpose, & Application
This Technical Report provides an overview of interfaces between IP Multimedia Subsystem (IMS)-based carriers and Public Safety 9-1-1 service systems (as described in ATIS-0700015).
ATIS-0700015, Implementation of 3GPP Common IMS Emergency Procedures for IMS Origination and ESInet/Legacy Selective Router Termination, identifies and adapts as necessary 3GPP common IMS emergency procedures for applicability in North America. IMS is a global telecommunications standard developed by 3GPP that supports emergency communications originating from an IMS subscriber (fixed, nomadic, or mobile) and delivered to an E9-1-1 system or to an NG9-1-1 Emergency Services IP network (ESInet). The first version of this standard was limited to voice and Global Text Telephony (GTT1) communication. A subsequent version of ATIS- 0700015 included procedures for addressing additional media (i.e., text, pictures, video) in support of Multimedia Emergency Services (MMES).
For calls destined to legacy emergency services networks, ATIS-0700015 results in the same signaling when delivering emergency calls from IMS-based originating networks as for emergency calls from legacy originating networks. Therefore, operators of those networks and the Public Safety Answering Points (PSAPs) behind them should expect no changes in their processes.
For calls destined to NG9-1-1 ESInets, ATIS-0700015 results in the same signaling when delivering emergency calls from an IMS-based originating network as is defined for delivering calls from IP-based originating networks toward NG9-1-1 PSAPs. Therefore, operators of ESInets and the PSAPs behind them should anticipate similar processes as with other IP-originating networks.