A link twin with independent packet loss says to send repeats back to back: what does burstiness do to repetition coding for shared maps, and what does spacing buy?

research/interleave-twin

Independent-loss link twin vs a bursty loss chain for repeated map updates: exact residual p·q_g^(r−1), the twin's 5 back-to-back copies leave 81–311× the claimed loss at λ=0.5–0.8, spacing needs 6–36 slots for two copies, and with ≤8 copies the best design is 12–154 slots of latency vs the twin's 4.

10 tests

What it found

An update is sent as r copies g slots apart and is lost only if all are. Against a two-state loss chain with the same marginal rate p = 0.2 and lag-1 correlation λ, the exact residual is p(p + λ^g(1−p))^r−1 against the twin’s p^r. The twin’s 5 back-to-back copies for 10⁻³ give a real residual of 0.026 at λ = 0.5 and 0.10 at 0.8 (81× and 311× the claim); two copies need spacing of 6 to 36 slots to come within 10% of the twin. With at most 8 copies the minimum-latency design is 12 to 154 slots (λ = 0.5 to 0.95) against the twin’s 4, and with at most 4 copies no spacing reaches 10⁻³. A counter-case: with no copy budget and a long deadline, back-to-back copies still beat a few spaced ones. Stylised: simulated link, known stationary parameters, no radio traces.

A figure from its own output

Figure produced by research/interleave-twin: residual_vs_lam — interleave-twin/experiments/residual_vs_lam.svg, written by the project's own experiment code.

Paper, code and results

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Produced with AI assistance (Claude). Results are from the code in this repository and are simulated or stylised unless the abstract says otherwise; nothing here implies affiliation with or endorsement by any lab, researcher or company cited. MIT licensed.