NG112 reference

Ims Emergency Calling

Structured NG112 reference page.

112 readiness

Policy, location, routing, and response quality connected in one operational model.

Mobile and IMS

IMS Emergency Calling

IP Multimedia Subsystem Emergency Calling

IMS is not NG112, but modern mobile emergency calling heavily interacts with IMS. VoLTE, VoNR and some NG eCall paths depend on IMS behavior for emergency registration, service identification, location support, roaming and interconnection toward emergency services.

IMS is not NG112, but mobile NG emergency calling often depends on IMS architecture.

User equipment

Access network

IMS emergency session

Emergency interconnect

PSAP

What it does

IMS emergency calling describes how mobile networks establish emergency sessions over IP-based mobile core architecture.

IMS can be the mobile access architecture feeding emergency sessions and location into 112/E112/NG112 environments.

How it works

The device identifies an emergency session and uses the mobile access and IMS core to establish service.
The network handles emergency registration or emergency session procedures where applicable.
Location, routing and interconnect behavior depend on national mobile and emergency-services implementation.

Key interfaces and protocols

3GPP TS 23.167
3GPP TS 24.229
SIP/SDP
Mobile location interfaces

Systems it interacts with

VoLTE
VoNR
Emergency roaming
Mobile location
NG eCall

Common failure modes

Roaming emergency support differs by operator or visited network.
Fallback assumptions break after 2G/3G retirement.
Location reaches emergency services late or through a separate channel.
IMS service identity is not mapped correctly at interconnect.

Implementation considerations

Verify country and operator behavior, especially for roaming.
Test emergency calling during radio access transitions.
Do not describe IMS deployment as proof of NG112 deployment.

Standards

3GPP TS 23.167
3GPP TS 24.229

Related NG112 technologies

Relationship graph

Mobile chain: IMS Emergency Calling <-> VoLTE Emergency Calling <-> VoNR Emergency Calling <-> Emergency Roaming <-> NG eCall

VoLTE Emergency Calling VoNR Emergency Calling Wi-Fi Calling Emergency Access Emergency Roaming Mobile Location NG eCall

Related country deployments

No country deployments are listed here until independently verified against official or high-confidence sources.

Mobile Location

Sources

3GPP TS 23.167: IMS emergency sessions - 3GPP, accessed 2026-08-31
3GPP TS 24.229: IMS call control protocol based on SIP and SDP - 3GPP, accessed 2026-08-31
112: the European emergency number - European Commission, accessed 2026-08-31
Directive (EU) 2018/1972 establishing the European Electronic Communications Code - European Union, accessed 2026-08-31
Next Generation 112 and the new Emergency Services Networks Landscape - EENA, accessed 2026-08-31

Last verified: 2026-08-31