How a Reading Travels.
Follow one reading from the water to the shore database. Six steps, each shaped by a real constraint (of the ocean, of the battery, or of radio law).
1. Sample. A sensor node gathers localized environmental data: say, a temperature reading every 3 seconds. Sent naively as one packet per reading over a low-bandwidth LoRa link, that stream would drown in its own packet headers: runaway overhead, regulatory duty-cycle violations (the law caps how long a radio may occupy the air), and heavy battery drain.
2. Shrink it: send only the change. Ocean readings drift slowly; the temperature a few seconds from now is very close to the last one. So the node collects a batch of readings, sends the first one in full, then sends only the tiny difference from each reading to the next (a few bits each instead of a full 32). The gateway adds the differences back up to rebuild the exact original series: nothing lost, but far fewer bytes over the air. (How the encoder works, below.)
3. Listen before transmitting. Before the node fires anything, it listens to make sure the channel is clear, the same "wait for a gap" courtesy your Wi-Fi uses. (How that works in silicon, below.)
4. If the air is jammed, store and wait. Buoys drift into RF dead zones, pass behind large swells, or suffer atmospheric interference. Blindly transmitting into a network blackout loses the data permanently. So no reading is ever lost: when the node detects a failed transmission (via missing LoRaWAN ACKs [acknowledgment replies] or CSMA-CA channel jamming), the Phase 2 firmware writes the compressed reading to its on-board SD card buffer and holds on. The node can survive offline for weeks, quietly accumulating environmental history.
5. Bulk transfer ashore. Once a connection to the mesh is re-established (proven by receiving a network heartbeat from a passing LR1121 relay or the T-ETH-ELITE), the node automatically flushes its SD-card buffer, sequentially replaying its queue and reconstructing the historical timeline within the Federated Data Broker, the central database on shore.
6. Two formats, one meaning. Over the air the reading rides in a dense 84-byte binary frame; the moment it reaches the gateway, it is translated into a standard, self-describing envelope the rest of the world can read. (The dual-layer protocol, below.)