NG112 reference
Wifi Calling
Structured NG112 reference page.
112 readiness
Policy, location, routing, and response quality connected in one operational model.
Mobile and IMS
Wi-Fi Calling Emergency Access
Wi-Fi calling can make a mobile device behave like it is reachable through an IP access network rather than a macro cellular site. Emergency location may depend on registered addresses, device-derived location, network-derived clues or operator-specific behavior.
What it does
Wi-Fi calling creates emergency-location challenges because the voice access path may not reveal the caller's physical location.
It is an access-network case that tests whether emergency location remains accurate away from cellular coverage.
How it works
- The device uses Wi-Fi and operator voice services to place a call.
- The operator determines emergency handling and location mechanisms.
- Fallback may occur if emergency calling over Wi-Fi is unsupported or unreliable.
Key interfaces and protocols
- IMS emergency procedures
- Registered address workflows
- Handset location
- Wi-Fi/network context
Systems it interacts with
- IMS emergency calling
- Mobile location
- Indoor location
- AML
- PSAP
Common failure modes
- Registered address is stale after travel.
- Wi-Fi access hides national location.
- Indoor location is too coarse.
- Fallback to cellular fails in weak coverage.
Implementation considerations
- Warn users where registered address matters.
- Test office, home, hotel and roaming cases.
- Coordinate with mobile operators on country-specific behavior.
Standards
- 3GPP emergency calling architecture
- National emergency communications rules
Related NG112 technologies
Related country deployments
No country deployments are listed here until independently verified against official or high-confidence sources.
Related articles
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