NG112 reference
Held
Structured NG112 reference page.
112 readiness
Policy, location, routing, and response quality connected in one operational model.
Location
HELD
HTTP-Enabled Location Delivery
HELD is the request/response mechanism. The LIS is the system that answers. PIDF-LO is often the representation returned. Keeping those roles separate prevents bad enterprise designs where a phone has a protocol configured but no trustworthy data source behind it.
What it does
HELD is a protocol that lets an endpoint or client request location from a Location Information Server.
HELD helps endpoints obtain usable emergency location before or during an emergency session.
How it works
- A HELD client requests location from a LIS.
- The LIS maps network or endpoint context to civic or geodetic data.
- The response can provide location by value or, where supported, a reference.
Key interfaces and protocols
- HTTP/TLS
- IETF RFC 5985
- PIDF-LO
- LIS provisioning
Systems it interacts with
- Endpoint
- LIS
- Enterprise network inventory
- SIP emergency client
- Location validation
Common failure modes
- Endpoint cannot reach the LIS.
- Network identifiers map to stale locations.
- Remote users receive office location.
- Location reference expires before emergency use.
Implementation considerations
- Tie network inventory lifecycle to location data lifecycle.
- Test subnets, Wi-Fi, switch ports and remote-client behavior.
- Log enough to troubleshoot without over-retaining sensitive location data.
Standards
- IETF RFC 5985
- IETF RFC 4119
Related NG112 technologies
Relationship graph
Location chain: Emergency Location Chain <-> LIS <-> HELD <-> PIDF-LO <-> SIP Geolocation <-> Location-Based Routing
Related country deployments
No country deployments are listed here until independently verified against official or high-confidence sources.
Related articles
Sources
- RFC 5985: HTTP-Enabled Location Delivery - IETF, accessed 2026-08-31
- RFC 4119: A Presence-based GEOPRIV Location Object Format - IETF, accessed 2026-08-31
- ETSI TS 103 479 deliverable directory - ETSI, accessed 2026-08-31
Last verified: 2026-08-31