Design Decisions & Discriminators
This document turns the big idea into “what would change our mind” tests.
1. Undersea vs. Surface vs. Satellite
When Each Wins
| Technology | Wins | Loses |
|---|---|---|
| Fiber | Deterministic low latency, high capacity, predictable QoS | Repair logistics, sabotage risk, permitting complexity |
| LEO/MEO sat | Coverage, rapid deployment, redundancy | Variable latency/jitter, weather fade, shared spectrum |
| Surface RF (VDES/HF) | Resilient messaging, maritime safety, regulatory clarity | Low capacity, not broadband |
Discriminator Tests
- RTT measurements: fiber landing→edge→core vs sat failover
- Fault isolation drill: simulated cut + time-to-repair vs contractual SLAs
2. Cold Climate: Net Win Only If You Design the Envelope
Pros
- Reduced cooling hours and lower mechanical load
- Easier heat export to district heating
Cons
- Icing, snow loads, corrosion, supply chain delays
- Humidity/dewpoint control still required
Discriminator Tests
- Measured PUE and WUE year-round for a pilot modular DC
- Cold-start and freeze/thaw reliability testing
3. Fab Adjacency: Don’t Confuse “Cool Air” with “Cheap Fab”
Fabs are dominated by:
- Cleanroom HVAC recirculation
- UPW consumption
- Process tool power
Discriminator Tests
- Detailed energy model of cleanroom + tool loads
- Water source + treatment feasibility including winter ops
4. Security Posture: Design for “Harvest Now, Decrypt Later”
Any long-lived sensitive data should assume future cryptanalytic capability.
Discriminator Tests
- Inventory all protocols with long-lived confidentiality requirements
- PQC pilot: deploy ML-KEM in non-critical paths, measure overhead
5. Governance: Landlord Model vs. Operator Model
| Model | Pros | Cons |
|---|---|---|
| Landlord | Competition, avoids capture | Coordination complexity |
| Operator | Faster execution | Governance and capture risk |
Discriminator Tests
- Tender responses: number of credible carrier/anchor tenants
- Regulatory acceptability in each jurisdiction
6. Mesh + Community Resilience
Meshtastic/LoRa mesh is a “last 50 km” resilience layer, not a backbone.
Discriminator Tests
- Multi-node field trials in winter: range, reliability, battery life, duty cycles
Summary
Every major design choice should have:
- Clear criteria — what would make us choose differently
- Measurable tests — how we validate our assumptions
- Fallback plan — what we do if the test fails