29. Telemetry, media, and evidence ingestion data plane
High-rate samples and large media do not belong inside the semantic ledger. The ingestion plane validates producer identity, capture context, clock quality, schema and chunk integrity; stores immutable artifacts; then appends a compact manifest record that…
Concept & directionLNK
High-rate samples and large media do not belong inside the semantic ledger. The ingestion plane validates producer identity, capture context, clock quality, schema and chunk integrity; stores immutable artifacts; then appends a compact manifest record that makes the data discoverable and reproducible. A segment can be useful despite dropout, clock drift or expired calibration only when those limitations remain explicit.
#29.1 Capture session and producer contract
| Area | Required fields |
|---|---|
| scope | asset/assembly, exact configuration, operation/mission/phase, operator/controller, environment and privacy context |
| producer | device/controller/logger instance, hardware/firmware/software build, boot/session ID, key epoch and attestation state |
| clock | clock ID, epoch, resolution, monotonicity, synchronization method, offset, drift model, uncertainty and discontinuities |
| channel schema | stable channel ID, phenomenon/quantity kind, feature of interest, datatype, unit, frame, sign convention and null/quality encoding |
| sampling | nominal/variable rate, trigger, pre/post window, resampling/interpolation policy, anti-alias/filter and event-versus-periodic behavior |
| calibration | sensor/measurement-chain calibration, validity, coefficients/artifact, environment and applicability |
| segmentation | producer sequence range, start/end clocks, target duration/size, compression, encryption and rolling digest policy |
| policy | field sensitivity, precise-location treatment, retention, consent/legal basis, permitted derivations, export and disclosure |
#29.2 SegmentManifest v2
Telemetry segment manifest - illustrative JSON
{
"segmentId": "seg:sha256:...",
"captureSessionId": "018f...55",
"assetId": "018f...aa",
"configurationId": "cfg:sha256:...",
"operationSegmentId": "record:operation-segment",
"producer": {"deviceId": "018f...d1", "bootId": "boot:...", "sequence": {"first": "19000", "last": "24999"}},
"time": {"sourceStart": "812.004000", "sourceEnd": "872.004000", "clockModelRef": "record:clock-model"},
"schemaRef": {"id": "schema:rtracer.telemetry.road-basic/v3", "digest": "sha256:..."},
"channels": [{"channelId": "wheel.speed.fl", "column": "c17", "unit": "km/h", "qualityColumn": "q17"}],
"artifact": {"artifactId": "artifact:...", "format": "application/vnd.apache.parquet", "digest": "sha256:...", "bytes": "2481901"},
"statistics": {"rows": "6000", "dropouts": "4", "duplicateSamples": "0", "clockUncertaintySeconds": "0.002"},
"privacyPolicyRef": "policy:vehicle-telemetry-private/v2"
}#29.3 Ingestion stages and disposition
| Stage | Checks | Failure behavior |
|---|---|---|
| admission | tenant/device authorization, content length, media type, rate/quota and session state | reject without revealing inaccessible entity state |
| transport | chunk framing, compression ratio, encryption/authentication, nonce/replay window and timeout | retry-safe rejection or bounded quarantine |
| syntax | format parser limits, schema footer/header, row/column counts, type and dictionary bounds | quarantine original bytes; no partial projection |
| integrity | artifact digest, segment ID, producer sequence, duplicate/collision and object-store confirmation | deduplicate exact retry; quarantine equivocation |
| semantic | channel schema lock, units, frames, clock model, calibration, configuration and operation references | accept-with-quality, quarantine or reject per rule |
| privacy | sensitive channels, precise location, people/media, retention, export and derived-feature permission | encrypt/segregate, redact projection or reject |
| commit | artifact durable, manifest canonical, subject links and outbox atomic | compensate orphan object or retry transaction |
| post-process | statistics, thumbnails, indexes, derived metrics and anomaly jobs | retry independently; manifest remains source |
#29.4 Time, ordering, and duplicate semantics
- Producer sequence establishes order within one boot/session only; it is never assumed globally unique.
- Source time, synchronized estimate, server arrival time and ledger recorded time are retained separately.
- A clock discontinuity creates a new clock-model interval; timestamps are not rewritten to hide the discontinuity.
- Exact duplicate segment ID plus digest is idempotent. Same ID/index with different bytes is equivocation and quarantined.
- Late and out-of-order segments are accepted when policy allows, then projections revise their completeness watermark.
- Cross-device correlation reports uncertainty. Apparent simultaneity within uncertain clocks is not ordered fact.
- Event-time windows close under a declared lateness policy; a later segment can trigger correction/rebuild, not historical deletion.
#29.5 Channel evolution and adapters
| Change | Treatment |
|---|---|
| new optional channel | new schema version; old segments remain valid; projection exposes coverage |
| channel rename | stable channel concept plus alias/migration; original source name retained |
| unit change | new schema version; exact conversion adapter and original unit/value preserved |
| datatype widening | compatibility declared only if all old values round-trip and null/quality semantics match |
| scale/offset correction | calibration or adapter record; never rewrite raw column bytes |
| different bus/source | new source namespace and mapping evidence; same physical phenomenon may remain separate observations |
| proprietary encrypted field | opaque namespaced column may be retained; accessibility and key state explicit |
| unsupported future channel | round-trip artifact and manifest; mark unsupported without discarding segment |
#29.6 Media and sensor-fusion evidence
| Evidence family | Minimum provenance |
|---|---|
| camera/photo/video | capture device/lens, orientation, timing, exposure, calibration, edits, people/plate/location privacy and rights |
| audio | microphone chain, gain, clock, channel geometry, speech/voice rights, redaction and synthetic/edited disclosure |
| LiDAR/radar/sonar | sensor pose/frame, scan pattern, timing, environment, calibration, returns/filtering and safety constraints |
| GNSS/navigation | receiver/antenna, constellation/source, datum/frame, solution type, covariance, corrections and outage/spoof flags |
| derived fusion | input segment/artifact IDs, time alignment, transforms, algorithm/model digest, parameters, output uncertainty and receipt |
| annotation | annotator/agent, vocabulary version, geometry/time span, confidence semantics, review and source evidence |
#29.7 Hot, warm, and archival data classes
| Class | Purpose | Rules |
|---|---|---|
| hot | recent operations, live owner view and bounded alerts | short retention, strict access, backpressure, no public precise location |
| warm | recent history, comparisons, maintenance and event media | indexed segments, derived summaries, policy-bound retrieval |
| cold | long-term lifecycle evidence and regulatory/owner archive | immutable object lock where required, integrity scrub and restore tests |
| legal/incident hold | preservation under authorized process | separate hold authority, scope, review, expiry and audit; not a blanket policy override |
| expired/deleted | retention or lawful deletion outcome | key/payload disposal plus non-sensitive tombstone and deletion receipt when appropriate |