draft-papadopoulos-hemb-00 (planned Internet-Draft; submission target January 2027) RFC Series, Independent Submission Stream · intended status Informational (outside the IETF standards process; publication is the Independent Submissions Editor's decision)
- Prior art research: Summary published; the three research passes behind it are not yet in the repository
- Reference implementation: Measured on hardware (246 generations decoded, 0 failed). Not yet independently reproduced
- Field hardware validation: LoRa, TCP and SMS confirmed April 2026. A paid satellite bearer has not yet carried symbols
- RFC submission target: January 2027
In disaster response, maritime, polar, and contested environments, the surviving communication channels — LoRa mesh radio, Iridium satellite SBD, APRS/AX.25, SMS, and GSM ring signals — share no common protocol stack. They differ in MTU by five orders of magnitude (1 byte to 100 KB), in latency by three orders of magnitude (100 ms to 90 s), and in cost by an unbounded factor (EUR 0 to EUR 0,05/msg).
In the searches conducted, no existing protocol was found that bonds these bearers simultaneously with coded redundancy. MPTCP, MP-QUIC, and GRE bonding require IP on every subflow. LACP requires homogeneous Ethernet. DTN provides store-and-forward but not simultaneous multi-bearer coding.
HeMB bonds N physical bearers into one virtual bearer using Random Linear Network Coding (RLNC) over GF(256). Any K of N coded symbols from any bearer combination reconstruct the original payload — arrival order and bearer identity are irrelevant. Allocation is free-first: with any free bearer online, source symbols go to free bearers and paid bearers are held at zero. The full capacity-aware cost semantics (what "free capacity exhausted" means, paid activation thresholds) are not yet formalised — defining them precisely, with conformance vectors, is part of the specification work.
HeMB does not claim novelty in RLNC, any-K-of-N recovery, or multipath transmission. These are well-established (Ho 2006, RFC 5053, US9537759B2).
HeMB's contribution is the combination:
- Operation directly over bearer adapters with no common protocol-stack requirement — bearers need not share IP, TCP or framing (IP transports may participate as bearers alongside non-IP radios)
- Concurrent coded reconstruction — one payload rebuilt from symbols dispatched over several dissimilar bearers at once
- Monetary cost as a primary allocation constraint — free-first policy today (paid bearers held at zero while any free bearer is online); the full capacity/activation semantics are specification work
Large latency-ratio operation (design envelope up to 900:1, Iridium SBD 90 s vs ZigBee 100 ms) is a design requirement and test dimension, not a novelty claim. Measured to date: ~60:1 (TCP vs LoRa); satellite ratios are projected, pending a paid-bearer measurement campaign. The closest network-coded multipath prior art (US9537759B2, over TCP/IP subflows) numerically evaluated ratios around 100:1.
In the searches conducted, no prior system was found addressing this combination (see prior-art/summary.md for scope and the closest works).
| Metric | Value | Scope |
|---|---|---|
| Generations decoded | 246 | cumulative, bench + field runs (two-bearer bond mesh_0+tcp_0 for the stress evidence) |
| Generations failed | 0 | same scope |
| Decode latency P50 | 0 ms | local decode, TCP-dominant path |
| Decode latency P95 | 25 ms | local decode |
| Symbols sent (stress test) | 9.675 | 1.000-payload run, 2026-03-30; raw per-attempt log published in the MeshSat repo (docs/evidence/hemb_stress_20260330_033905.jsonl) — 830 delivered, 170 failed, of which 168 form one contiguous run (attempts 833–1000) after total bearer loss |
| Cost incurred | EUR 0,00 | no paid bearer carried symbols to date |
| Bugs found and fixed | 10 | E2E integration, 2026-03-30/31 |
| Tests (3 codebases) | 65 passing | HeMB-specific tests only |
spec/
sections/ RFC draft sections (abstract, intro, related work, etc.)
prior-art/ Prior-art summary; underlying search passes retained, not yet published
field-data/ Production hardware validation results
impl/ Reference implementation notes
tools/ Build scripts (xml2rfc)
The reference implementation lives in MeshSat: https://github.com/meshsat/meshsat/tree/main/internal/hemb
Partial ports derived from the Go implementation (shared design, bug fixes backported — not independent implementations):
- MeshSat Hub (decode-path integration,
internal/protocol/hemb_*.go): https://github.com/meshsat/meshsat-hub - MeshSat Android (
hemb/+rlnc/packages): https://github.com/meshsat/meshsat-android
A specification-derived independent implementation does not yet exist; producing one, against published conformance vectors, is planned work.
- MeshSat — Multi-transport mesh and satellite gateway (reference implementation)
Kyriakos Papadopoulos · Leiden, Netherlands kyriakos@papadopoulos.tech
Apache 2.0 (see LICENSE) — specification and documentation Reference implementation: GPLv3 (via MeshSat)