Communications Layer: Last-Mile & Failsafes
This is where projects die if you don’t include it.
The communications layer ensures connectivity reaches communities and vessels, with fallbacks when primary links fail.
Primary Backbones
| Type | Role |
|---|---|
| Subsea fiber | Primary capacity, lowest latency |
| Microwave / terrestrial fiber | Spurs to landing sites |
Secondary / Resilient Comms
LEO Satcom (Starlink-class)
- Maritime and high-latitude connectivity
- Backup for non-core sites
- Rapid deployment capability
3GPP Non-Terrestrial Networks (NTN)
- Standards-based satellite integration path
- Mass device connectivity (mid-term)
- Interoperable with terrestrial 5G
VDES (VHF Data Exchange System)
- Maritime digital comms evolution beyond AIS
- Ship traffic coordination
- Coastal systems integration
Local Mesh / Community Resilience
LoRaWAN and Meshtastic
For communities, sensors, and emergency paging where infrastructure is sparse:
| Attribute | Value |
|---|---|
| Range | 2-15 km (terrain dependent) |
| Power | Very low (battery/solar viable) |
| Data rate | Low (text, telemetry) |
| Use case | Last-50-km resilience |
HF Radio + Digital Modes
Backstop for “everything is down” conditions:
- No infrastructure dependency
- Global reach (ionospheric propagation)
- Requires operator training
Latency Comparison
| Link Type | Typical RTT |
|---|---|
| Undersea fiber | 5-20 ms (distance dependent) |
| LEO satellite | 20-40 ms |
| GEO satellite | 600+ ms |
| HF radio | Variable (protocol overhead) |
Fiber wins on deterministic low-latency; sat is resilience/coverage.
Key References
- ITU-R M.2092-1 (VDES)
- Nokia 3GPP NTN / BEREC 2024