Technical reference
NG112 Architecture
Originating networks, ESInet functions, location, SIP signaling, routing policy and PSAP call handling in one implementation-oriented reference.
112 readiness
Policy, location, routing, and response quality connected in one operational model.
Step 1
Caller / Device
Step 2
Originating network
Step 3
Emergency Services IP Network
Step 4
ESRP
Step 5
ECRF / policy / location routing
Step 6
PSAP
This is a simplified reference flow. Real national deployments may differ in routing ownership, policy functions, location validation, PSAP interconnect, media support, and transition strategy.
ESInet
An Emergency Services IP Network is the managed emergency-services network that carries IP emergency sessions and related data between originating networks, routing functions and PSAPs.
ESRP
An ESRP is a SIP-aware emergency routing proxy that helps route an emergency session according to location, service and policy.
ECRF
An ECRF maps a caller location and requested emergency service to routing information for the appropriate emergency destination.
LVF
An LVF checks whether civic location data is valid enough to be used for emergency communications.
BCF
A Border Control Function protects NG112 network boundaries and controls emergency session interconnection.
PSAP Interconnect
PSAP interconnect describes how emergency centers connect to NG112 service networks and adjacent PSAPs.
DNS and Service Discovery
DNS and service discovery support reliable discovery of emergency services, routing elements and dependent network functions where architectures use them.
Policy Routing
Policy routing applies operational rules to emergency session routing beyond the simple fact of where the caller is located.
Failover and Alternate Routing
Failover and alternate routing define where emergency sessions go when the normal path, function or PSAP cannot take the call.
Emergency Location Chain
Emergency location is a chain of separate functions: determining location, representing it, conveying it, validating it and using it for routing and display.
PIDF-LO
PIDF-LO is an XML-based location object used to represent civic or geodetic location information for emergency communications.
HELD
HELD is a protocol that lets an endpoint or client request location from a Location Information Server.
LIS
A Location Information Server provides location information based on endpoint, network or access context.
Civic Location
Civic location describes a caller using address-style fields such as country, city, street, building, floor, room or area.
Geodetic Location
Geodetic location represents position using coordinates such as latitude and longitude, often with uncertainty or confidence information.
Indoor Location
Indoor location focuses on making emergency location actionable inside buildings, campuses, factories, warehouses and public spaces.
Advanced Mobile Location
Advanced Mobile Location improves mobile emergency caller location by sending handset-derived location to emergency services where nationally supported.
SIP Emergency Signaling
SIP can establish emergency voice, text or multimedia sessions and convey or reference location for routing and PSAP handling.
SIP Geolocation
SIP Geolocation is the signaling mechanism used to carry or reference location information in a SIP session.
Emergency Service URNs
Emergency service URNs identify emergency services logically, such as urn:service:sos, instead of relying only on dialed digits.
LoST
LoST is a protocol concept for translating location plus requested service into routing information for that service.
Location-Based Routing
Location-based routing selects the emergency destination using where the caller is and what emergency service is requested.
IMS Emergency Calling
IMS emergency calling describes how mobile networks establish emergency sessions over IP-based mobile core architecture.
VoLTE Emergency Calling
VoLTE emergency calling uses LTE access and IMS session control to place emergency calls over 4G networks.
VoNR Emergency Calling
VoNR emergency calling addresses emergency sessions in 5G standalone environments using IMS.
Wi-Fi Calling Emergency Access
Wi-Fi calling creates emergency-location challenges because the voice access path may not reveal the caller's physical location.
Emergency Roaming
Emergency roaming covers how callers expect 112 to work when they are outside their home network or country.
Mobile Location
Mobile location combines network-derived, handset-derived and sometimes app-derived evidence to locate a mobile emergency caller.
Real-Time Text
Real-Time Text sends characters as they are typed, enabling conversational text during emergency communications.
Total Conversation
Total Conversation combines audio, video and real-time text in one accessible communication model.
Emergency Video
Emergency video can give PSAPs visual context, but it changes bandwidth, workflow, privacy and evidence-handling requirements.
Emergency Text
Emergency text covers text-based emergency access mechanisms and should be distinguished from Real-Time Text.
Accessibility
Accessibility makes emergency communications usable for people who cannot rely on ordinary voice calling.
Multimedia Negotiation
Multimedia negotiation determines which media streams an emergency session can actually use.
Fallback Behavior
Fallback behavior defines what happens when location, media, routing or network support is incomplete.
Additional Emergency Data
Additional emergency data is information beyond the media session and basic location that may help emergency response.
IoT Emergency Data
IoT emergency data may support emergency response, but arbitrary devices should not be assumed to access NG112 directly.
eCall
eCall is vehicle-originated emergency calling to 112, carrying voice and a Minimum Set of Data from the vehicle.
NG eCall
NG eCall is the next-generation evolution of vehicle emergency calling toward modern IP/IMS mobile environments.
eCall Minimum Set of Data
The Minimum Set of Data is the structured vehicle and incident information sent with an eCall.
PEMEA
PEMEA supports interoperability for emergency applications across borders and emergency-service domains.
Emergency Apps
Emergency apps can provide alternative access, location and data, but they must fit official emergency-service workflows.
PSAP Technology
A PSAP is the emergency answering center where calls or sessions are answered, assessed and coordinated.
IP Call Handling
IP call handling is the PSAP-side capability to answer and manage emergency sessions delivered through modern IP networks.
GIS for Emergency Routing
GIS supports service boundaries, map display and location interpretation for emergency routing and PSAP operations.
CAD Integration
CAD integration connects emergency intake information with dispatch workflows and incident management.
Recording and Audit
Recording and audit capture emergency sessions, media, metadata and operational decisions for review and legal retention.
Multimedia PSAP
A multimedia PSAP can receive and manage more than ordinary voice, including text, video and emergency data where supported.
NG112 Security
NG112 security protects emergency signaling, media, data and network boundaries while preserving availability.
TLS for Emergency Signaling
TLS can protect emergency signaling confidentiality and integrity where supported by the architecture.
Secure RTP
SRTP can protect emergency media streams where end-to-end architecture and PSAP support allow it.
DDoS Protection
DDoS protection helps keep emergency networks reachable during traffic floods and hostile activity.
Identity and Authentication
Identity and authentication help emergency systems decide which networks, services and data sources are trusted.
Network Segmentation
Network segmentation limits how failures or attacks move across emergency communications infrastructure.
Resilience
Resilience keeps emergency communications working through failures, disasters and degraded conditions.
Testing and Interoperability
Testing proves whether specifications, independent implementations and the full emergency path actually work.