Overview#
A naval task force has autonomous underwater vehicles operating ahead of the formation. Surface communications are not an option at depth. The AUVs transmit position and navigation data acoustically, and the operations team at the surface vessel needs to know whether those packets are arriving, how many navigation messages have come through in the last hour, and whether any modem has gone silent. JANUS, standardised as STANAG 4748, is the NATO standard for underwater acoustic communications, and it provides the common protocol layer that makes different acoustic modem types interoperable in coalition maritime operations.
The JANUS Underwater Acoustic Communications module provides an operational view of acoustic modem connectivity and underwater message traffic. Maritime and underwater operators track connected modems, packet activity, navigation-message volume, and the recency of the latest acoustic traffic to monitor subsea communications readiness in real time.
Open Standards#
- STANAG 4748 / ANEP-87 (JANUS): The module implements JANUS, the NATO standard for digital underwater acoustic signalling, parsing JANUS packet headers, cargo application-type identifiers, and App-1 navigation payloads as defined in ANEP-87 Table 6.
- WGS-84: All transmitter position coordinates carried in JANUS navigation payloads and stored in the packet log use WGS-84 decimal-degree latitude and longitude, consistent with NATO geodetic datum requirements for maritime operations.
- GraphQL: The module exposes modem polling and packet query operations via a Strawberry GraphQL schema, allowing clients to retrieve packet lists and trigger modem polls through a typed query and mutation interface.
- OAuth 2.0 / OpenID Connect: Access to JANUS packet data and modem control mutations is gated by authenticated sessions issued through the platform's OAuth 2.0 / OIDC identity layer, enforced on every GraphQL resolver via permission classes.
- JSON: Modem communication uses a REST/HTTP JSON interface for polling received packets and submitting transmit requests; Base64-encoded payloads are exchanged within JSON envelopes to the JANUS software modem.
- ISO 8601: All packet receipt timestamps are stored and exchanged in ISO 8601 format with UTC timezone offsets, ensuring unambiguous temporal ordering of acoustic traffic across coalition systems.
Last Reviewed: 2026-03-25 Last Updated: 2026-04-14
Key Features#
- Connected Modem Monitoring: Shows how many modems are currently active in the acoustic network, giving operators a clear picture of subsea communications reach.
- Daily Packet Tracking: Tracks acoustic packet volume across the current day to reveal communications tempo and identify periods of unexpectedly low activity.
- Navigation Message Visibility: Highlights navigation-packet volume for mission workflows that depend on underwater position and movement exchange between assets.
- Recent Traffic Awareness: Surfaces the recency of the latest packet so operators can quickly detect stale or inactive links before they affect mission execution.
- Maritime Workflow Integration: Supports direct use in maritime operations, simulation, and messaging workbenches, with pivot paths to tactical communications surfaces.
Use Cases#
- Subsea Network Monitoring: Maritime operators monitor acoustic communications health during underwater operations, confirming that all expected nodes are connected and transmitting.
- Navigation Coordination: Teams confirm that navigation traffic is flowing correctly between connected underwater assets, including AUVs and seabed sensor nodes.
- Exercise and Test Oversight: Simulation and test teams validate that acoustic message traffic is present during drills or interoperability events aligned to STANAG 4748.
- Communications Fault Detection: Operators detect stalled or degraded acoustic traffic before it disrupts mission execution or leaves an underwater asset unreachable.
Integration#
- Acoustic modem networks and JANUS-compliant traffic (STANAG 4748)
- Maritime and subsea operational workflows
- Simulation and mission-messaging workbenches
- Shared communications and interoperability dashboards