Overview#
An ambulance crew responding to a cardiac arrest in a railway tunnel loses all mobile connectivity the moment they descend. With offline queueing active, the crew continues completing the electronic patient care record, logging medication administration, and updating triage status on their tablets without interruption. Every action is stored locally in an encrypted queue. The moment the vehicle surfaces and connectivity is restored, all recorded actions replay against the central system in the correct chronological order, with no data loss.
When two responders edit the same incident record independently during an outage, the platform detects the divergence on reconnection and presents a side-by-side visual diff. The user can review each conflicting field, choose which value to keep, or merge both contributions, before committing the final record. This guarantees that no observation is silently overwritten and that the audit trail remains complete.
Key Features#
- Encrypted Local Storage: All queued data, forms, and map tiles are stored on-device using strong encryption, ensuring sensitive operational data is protected even if a device is lost or seized.
- Chronological Action Queue: User actions such as edits, dispatch confirmations, and clinical notes are captured in strict time order and replayed faithfully on reconnection, preserving the correct event sequence.
- Visual Conflict Resolution: When the same record is modified by multiple users during an outage, a side-by-side field-level diff is presented, allowing the responder to review and merge changes with full visibility before committing.
- Sync Status Indicators: Persistent, unambiguous UI elements display connection state, the number of actions pending synchronisation, progress during replay, and any errors requiring manual attention.
- Selective Map and Form Caching: Frequently used map areas, incident templates, and protocol reference documents can be pre-cached so responders have the resources they need before entering a dead zone.
- Idempotent Replay: The synchronisation engine ensures that replaying a queued action more than once, for example after an interrupted sync, produces no duplicate records or unintended side effects.
- Conflict Audit Trail: Every resolved conflict is recorded with the original divergent values, the resolution decision, and the identity of the responder who made it, satisfying chain-of-custody requirements.
- Graceful Degradation: Non-critical features that require live connectivity degrade silently, while core incident documentation and communications remain fully functional offline.
Use Cases#
- Rural and Remote Operations: Crews responding to road traffic collisions on remote roads, or to incidents on farmland and in forests, continue full documentation without relying on intermittent rural network coverage.
- Subterranean and Confined-Space Incidents: Underground stations, basement car parks, and tunnel rescues often have no viable radio or LTE signal; full offline autonomy prevents data gaps in these high-stakes environments.
- Mass-Casualty Events: When a major incident saturates local cell infrastructure, multiple responders triage and document patients independently offline, with conflicts resolved systematically on reconnection rather than through manual reconciliation.
- Maritime and Aviation Operations: Coast guard and search-and-rescue crews operating beyond coastal network coverage rely on the queue to capture scene data, syncing via satellite or shore-based Wi-Fi on return.
- Planned Exercises and Drills: Multi-agency training exercises conducted in areas of deliberately suppressed communications can use the offline mode to generate realistic data that is consolidated into a shared exercise record at the end.
Integration#
The offline queueing and conflict resolution capability is built into the native mobile and tablet application, using the device's local storage with at-rest encryption. On reconnection the sync engine submits queued payloads to the platform's synchronisation API, which applies conflict detection using CRDT semantics and exposes any unresolvable divergences to the conflict resolution interface. The module integrates with the broader incident management workflow so that resolved records flow immediately into dispatch dashboards, reporting pipelines, and clinical audit systems without requiring separate manual import steps.
Open Standards#
- Conflict-free Replicated Data Types (CRDTs): The merge logic for concurrent edits is grounded in CRDT theory, ensuring that independently updated records converge to a consistent state regardless of the order in which updates arrive.
- JSON Patch (RFC 6902): Change deltas are encoded as JSON Patch documents during synchronisation, minimising payload size and providing a precise, human-readable record of exactly which fields changed.
- JSON Merge Patch (RFC 7396): Simpler partial-update payloads use the JSON Merge Patch format, complementing RFC 6902 for cases where a full diff is not required.
- Transport Layer Security (TLS 1.3, RFC 8446): All synchronisation traffic between the device and the backend is protected by TLS 1.3, ensuring data in transit is encrypted and authenticated.
- AES-256 (NIST FIPS 197): On-device queued data is encrypted using AES-256 in accordance with NIST FIPS 197, meeting the baseline encryption requirements for sensitive operational and clinical data.
- ISO 8601: All queued action timestamps are stored and transmitted in ISO 8601 format, guaranteeing unambiguous ordering across devices in different time zones.
- HL7 FHIR R4: Electronic patient care records queued offline conform to HL7 FHIR R4 resource structures, ensuring that clinical data synchronised on reconnection is immediately consumable by receiving health information systems.
Availability#
- Enterprise Plan: Included
- Professional Plan: Available with the Mobile Operations add-on; conflict resolution history retained for 90 days.
Last Reviewed: 2026-05-26