CONSTELLATION-RELAY: CRDT-over-DTN Tactical State Synchronization via Opportunistic LEO Contact Windows

DESCRIPTION

CONSTELLATION-RELAY is a fusion of Peat's CRDT-based tactical state synchronization with Delay-Tolerant Networking principles, enabling ground tactical cells to maintain coherent shared state across globally-distributed teams without depending on terrestrial mesh range or persistent connectivity. The fundamental insight: Peat handles disconnected operation in time (eventual consistency via CRDT mathematics) but assumes the network topology is reachable when connections are available. In contested or expeditionary operations, two cells might be separated by hundreds or thousands of kilometers with zero terrestrial mesh path between them — but both have intermittent LEO satellite visibility. Existing solutions like military SATCOM treat this as a circuit-switched problem requiring scheduled bandwidth allocation. CONSTELLATION-RELAY treats it as a CRDT-over-DTN problem instead: each cell maintains its local Automerge document, predicts upcoming LEO contact windows from ephemeris data, and during each contact pass uploads only the CRDT operation deltas that need to propagate to remote peers. The receiving cell, when its own contact window opens, downloads those deltas and merges them into its local state. The CRDT's mathematical convergence guarantees mean that even with arbitrary delays, partial deliveries, and out-of-order arrival, all cells eventually reach consistent state. Three things make this novel: (1) Contact-window-aware bundling — instead of streaming, the protocol batches CRDT ops into bundles sized to the predicted contact duration, with priority-aware truncation under bandwidth constraints. (2) Multi-constellation arbitrage — Starlink offers high bandwidth in short bursts, Iridium offers narrow but predictable global passband, and OneWeb sits between; the protocol selects the right constellation per bundle based on urgency and size. (3) Cryptographic continuity — each bundle is signed and chained so a compromised relay satellite cannot inject false state without breaking the hash chain. This is fundamentally different from any existing satellite communication architecture because it inherits CRDT's offline-first semantics rather than retrofitting them. The cross-domain leverage: most DTN research targets interplanetary missions (Mars rovers, deep space probes) and most CRDT research targets collaborative document editing — neither community has produced a tactical-grade fusion. Adjacent meta molecules HERMES-SAT (DTN-aware satellite voice) and ACCM-SUSTAIN (contested logistics) provide the architectural pattern but not the protocol layer. Use cases: globally-distributed special operations, maritime task forces, polar operations where terrestrial mesh is impossible, post-disaster civilian response where ground infrastructure is destroyed but LEO is intact.

REASONING

CONSTELLATION-RELAY is a sophisticated synthesis of three complex domains: Distributed Systems (CRDTs), Space Systems (SGP4/Ephemeris), and Delay-Tolerant Networking (BPv7). The primary defensibility lies in the 'arbitrage' and 'window-aware bundling' logic. Unlike standard sync tools like Ditto or Matrix, which focus on terrestrial mesh or persistent IP backhaul, this concept explicitly handles the orbital mechanics of LEO passes. The technical moat is significant; a competitor would need to build a cross-constellation driver (Starlink + Iridium + OneWeb) combined with a priority-aware CRDT delta engine. Frontier labs are unlikely to touch this as it is purely a 'harsh environment' hardware/protocol problem. The main commercial competitor is Ditto (ditto.live), which is making inroads into tactical state sync, but Ditto's current focus is primarily on terrestrial Peer-to-Peer and high-availability LANs rather than the high-latency, intermittent LEO-relay DTN model described here. The use of Peat and Automerge provides a solid open-source foundation while the specialized bundling logic creates a niche but deep competitive advantage in the defense/expeditionary tech sector.

COMPOSABILITY