NG112 reference

Lost

Structured NG112 reference page.

112 readiness

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

Location-Based Routing

LoST

Location-to-Service Translation

LoST helps explain how location-based emergency routing can work: a client or routing element asks, in effect, where should this service request go for this location? National NG112 systems may implement the ECRF concept using LoST-like behavior or different interfaces, so the distinction between protocol and deployed function should remain clear.

LoST is a protocol concept; ECRF is the emergency routing function that may use LoST-like behavior depending on architecture.

Location + service URN

LoST/ECRF query

Service URI

ESRP routing

PSAP

What it does

LoST is a protocol concept for translating location plus requested service into routing information for that service.

LoST is closely related to the ECRF function and location-based service routing.

How it works

Accepts a service identifier and location.
Matches the location against service boundaries.
Returns a URI or routing information for the appropriate service.

Key interfaces and protocols

IETF RFC 5222
IETF RFC 5031
GIS/service boundaries
ECRF concepts

Systems it interacts with

ECRF
ESRP
GIS
Emergency service URNs
PSAP

Common failure modes

Boundary data stale or incomplete.
Returned URI not reachable.
Location format cannot be interpreted.
Caching hides an updated service boundary.

Implementation considerations

Validate protocol behavior and operational data separately.
Test border cases and ambiguous locations.
Do not equate a LoST server purchase with national routing readiness.

Standards

IETF RFC 5222
IETF RFC 5031

Related NG112 technologies

Relationship graph

Routing chain: ESRP <-> ECRF <-> LoST <-> PSAP Technology <-> ESInet

ECRF Emergency Service URNs Location-Based Routing ESRP GIS for Emergency Routing

Related country deployments

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

NG112 Architecture

Sources

RFC 5222: LoST: A Location-to-Service Translation Protocol - IETF, accessed 2026-08-31
RFC 5031: A Uniform Resource Name for Emergency and Other Well-Known Services - IETF, accessed 2026-08-31
ETSI TS 103 479 deliverable directory - ETSI, accessed 2026-08-31

Last verified: 2026-08-31