{"id":"psap-ng911-real-time-text","slug":"psap-ng911-real-time-text","title":"PSAP NG911 / NG112 Real-Time Text","description":"Traditional SMS is useful for emergency messaging, but it is not the same as real-time text. In a critical situation, character-by-character exchange matters: a caller can start communicating before they finish typing, a","category":"geospatial","tags":["geospatial","real-time"],"lastModified":"2026-04-22","source_ref":"content/modules/psap-ng911-real-time-text.md","url":"/developers/psap-ng911-real-time-text","htmlPath":"/developers/psap-ng911-real-time-text","jsonPath":"/api/docs/modules/psap-ng911-real-time-text","markdownPath":"/api/docs/modules/psap-ng911-real-time-text?format=markdown","checksum":"2e4904d8e7b2cc8bcdd9b7f1f44942d648b4be45c4ba681b3a1444641bb07204","headings":[{"id":"overview","text":"Overview","level":2},{"id":"key-features","text":"Key Features","level":2},{"id":"use-cases","text":"Use Cases","level":2},{"id":"integration","text":"Integration","level":2},{"id":"open-standards","text":"Open Standards","level":2}],"markdown":"# PSAP NG911 / NG112 Real-Time Text\n\n## Overview\n\nTraditional SMS is useful for emergency messaging, but it is not the same as real-time text. In a critical situation, character-by-character exchange matters: a caller can start communicating before they finish typing, a dispatcher can see the conversation unfold live, and the experience works more like a text telephone conversation than an inbox. That is especially important for deaf, hard-of-hearing, speech-impaired, or silent callers.\n\nThe NG911 / NG112 Real-Time Text module gives the platform a standards-based RTT channel for PSAP workflows. It bridges the standards used on the emergency call side and the dispatcher side, preserves every accepted text fragment in the call record, and lets the communications centre treat RTT as a first-class emergency channel rather than a degraded fallback.\n\n```mermaid\nflowchart TD\n    A[Caller RTT Session] --> B[Emergency RTT Ingress]\n    B --> C[Standards Bridge]\n    C --> D[Dispatcher Console RTT View]\n    D --> E[Live Character-by-Character Exchange]\n    E --> F[Accepted Text Fragments]\n    F --> G[Call Record, QA, and Audit]\n```\n\n**Last Reviewed:** 2026-04-22\n**Last Updated:** 2026-04-22\n\n## Key Features\n\n- **Character-by-Character Emergency Messaging**: Support real-time text exchange where dispatchers can see the conversation as it is being typed.\n\n- **Standards Bridge Across Call and Console**: Bridge the transport used by the incoming emergency communication and the transport used by the dispatcher interface without forcing either side into a proprietary RTT model.\n\n- **Persistent Message Audit**: Preserve accepted RTT fragments inside the call record so QA, legal review, and post-incident analysis treat RTT on equal footing with voice and SMS.\n\n- **Typing-Cadence Awareness**: Make it possible for the operations environment to understand whether the text channel is active, stalled, or flowing under pressure.\n\n- **Backpressure and Resilience Handling**: Keep the RTT path moving during degraded conditions rather than blocking the emergency conversation because a downstream component is briefly slow.\n\n- **Accessible Channel for Silent and Vulnerable Callers**: Give PSAPs a standards-based channel that fits scenarios where voice is unsafe, impractical, or impossible.\n\n## Use Cases\n\n- **Deaf or Hard-of-Hearing Caller**: A caller uses RTT as their primary emergency communication method and experiences a live dispatch conversation rather than delayed SMS exchange.\n\n- **Silent Domestic Violence Incident**: A caller who cannot safely speak uses RTT to communicate with the dispatcher in real time.\n\n- **Speech-Impaired Medical Emergency**: A caller can get help through live text even where voice communication is too difficult under stress.\n\n- **Cross-Channel NG911 / NG112 Operations**: A modern PSAP handles voice, SMS, and RTT as distinct channels, each appropriate to different emergency conditions.\n\n- **Quality and Accreditation Review**: Supervisors review RTT exchanges with the same evidential confidence as other emergency communications.\n\n## Integration\n\n- **PSAP NG911 / NG112 Infrastructure**: RTT becomes part of the standards-based NG911 / NG112 call path rather than a side-channel add-on.\n\n- **Dispatcher Console**: Live text appears inside the same operational environment where dispatchers manage calls and incidents.\n\n- **Text-to-911 and Silent-Caller Workflows**: RTT complements SMS-oriented workflows by covering the true real-time text use case.\n\n- **Audit, QA, and Analytics**: Stored RTT fragments can feed training, fatigue analysis, and call-review programmes.\n\n## Open Standards\n\n- **RFC 4103**: the emergency-network side of the RTT flow follows the RTP payload standard for text conversation.\n\n- **RFC 8865**: the dispatcher-side WebRTC bridge uses the modern real-time text mapping for data-channel transport.\n\n- **ITU-T T.140**: text content follows the standard character representation used by interoperable RTT systems.\n\n- **W3C WebRTC**: dispatcher-side real-time text sessions can use the standard browser real-time communications model.\n\n- **RTP**: the emergency-call side uses the standard real-time transport protocol family for live text carriage.\n\n- **JSON**: session metadata and persisted audit records remain exchangeable in a standard structured format.\n"}