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Eric FELIXINE e0bf96b9c3 Docs: Ajout référentiel data-models (source/mqttTopic)

2026-05-04 22:39:27 -04:00

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Smart City Digital Twin - Data Models & Schemas

Vue d'ensemble

Ce document décrit les schémas de données utilisés par les différents brokers (MQTT, Fiware) avec les champs de traçabilité.

🔍 Champs de traçabilité (ajoutés le 05-05-2026)

Champ	Type NGSI-LD	Type SensorThings	Description
`source`	Property (valeur: string)	Thing.properties (valeur: string)	Broker MQTT source (ex: "EMQX", "Mosquitto", "BunkerM", "simulator")
`mqttTopic`	Property (valeur: string)	Thing.properties (valeur: string)	Topic MQTT d'origine (ex: "city/sensors/airquality/airquality_000")

Note : source est un champ standard NGSI-LD (ETSI). mqttTopic est une propriété personnalisée (autorisée par l'extension NGSI-LD).

1. NGSI-LD Entities (Orion-LD, Stellio)

Structure de base (avec traçabilité)

{
  "@context": [
    "https://uri.etsi.org/ngsi-ld/v1/ngsi-ld-core-context.jsonld"
  ],
  "id": "urn:ngsi-ld:AirQualityObserved:airquality_000",
  "type": "AirQualityObserved",
  "dateObserved": {"type": "Property", "value": "2026-05-05T02:00:00Z"},
  "location": {"type": "GeoProperty", "value": {"type": "Point", "coordinates": [-61.0, 14.6]}},
  "name": {"type": "Property", "value": "Port de Fort-de-France"},
  "batteryLevel": {"type": "Property", "value": 85},
  "source": {"type": "Property", "value": "EMQX"},
  "mqttTopic": {"type": "Property", "value": "city/sensors/airquality/airquality_000"}
}

Mapping Smart Data Models → NGSI-LD Types

Sensor Type	NGSI-LD Type	Exemple ID
airquality	AirQualityObserved	`urn:ngsi-ld:AirQualityObserved:airquality_000`
traffic	TrafficFlowObserved	`urn:ngsi-ld:TrafficFlowObserved:traffic_000`
parking	ParkingSpotObserved	`urn:ngsi-ld:ParkingSpotObserved:parking_000`
noise	NoiseLevelObserved	`urn:ngsi-ld:NoiseLevelObserved:noise_000`
weather	WeatherObserved	`urn:ngsi-ld:WeatherObserved:weather_000`
light	LightObserved	`urn:ngsi-ld:LightObserved:light_000`

2. SensorThings API (FROST-Server)

Thing Properties (avec traçabilité)

{
  "name": "Thing_airquality_000",
  "description": "Smart City airquality sensor in Martinique",
  "properties": {
    "sensorType": "airquality",
    "region": "Martinique",
    "source": "EMQX",
    "mqttTopic": "city/sensors/airquality/airquality_000"
  }
}

Datastream Structure

{
  "name": "Datastream airquality/pm25_ugm3",
  "description": "Datastream for airquality sensor airquality_000 - pm25_ugm3",
  "observationType": "http://www.opengis.net/def/observationType/OGC-OM/2.0/OM_Measurement",
  "unitOfMeasurement": {"name": "pm25_ugm3", "symbol": "µg/m³", "definition": "http://www.qudt.org/vocab/unit#MicrogramPerCubicMeter"},
  "Sensor": {...},
  "ObservedProperty": {...}
}

3. MQTT Topics (Brokers)

Format des topics

city/sensors/{sensor_type}/{sensor_id}

Exemples :

city/sensors/airquality/airquality_000
city/sensors/traffic/traffic_000
city/sensors/parking/parking_000

Mapping Topic → Entity ID

MQTT Topic	NGSI-LD Entity ID	SensorThings Thing ID
`city/sensors/airquality/airquality_000`	`urn:ngsi-ld:AirQualityObserved:airquality_000`	`Thing_airquality_000`
`city/sensors/traffic/traffic_000`	`urn:ngsi-ld:TrafficFlowObserved:traffic_000`	`Thing_traffic_000`

4. InfluxDB (Bucket: iot_data)

Measurements (v2 Flux)

airquality
traffic
parking
noise
weather
light

Fields

Valeurs spécifiques au type (ex: pm25_ugm3, co_mgm3, vehicle_count, etc.)

5. Procédure de mise à jour des payloads

⚠️ CHAQUE FOIS que les payloads sont modifiés (ajout/suppression de champs) :

Nettoyer les bases :

# Orion-LD
curl -s "http://localhost:2026/ngsi-ld/v1/entities?type=AirQualityObserved&limit=1000" | python3 -c "..."
# (Supprimer chaque entité)

# Stellio
# Via API Stellio (http://localhost:8087/ngsi-ld/v1/entities)

# FROST
# Via API FROST (http://localhost:8086/FROST-Server/v1.1/Things)

Mettre à jour ce document (references/data-models.md)
Tester avec un simulateur frais (entities recréées)

Committer et pousser vers Gitea :

git add references/data-models.md simulator.py
git commit -m "Update data models: add/remove fields"
git push origin master

6. Identification des messages par broker MQTT

Pour identifier quels messages ont été reçus par chaque broker Fiware :

Requête Orion-LD (source)

curl -s "http://localhost:2026/ngsi-ld/v1/entities?type=AirQualityObserved&limit=10" \
  -H "Accept: application/ld+json" | python3 -c "
import sys, json
data = json.load(sys.stdin)
for e in data:
    print(f\"{e['id']} | source: {e.get('source', {}).get('value')} | topic: {e.get('mqttTopic', {}).get('value')}\")
"

Requête Stellio (source)

curl -s "http://localhost:8087/ngsi-ld/v1/entities?type=AirQualityObserved&limit=10" \
  -H "Accept: application/ld+json" -H "NGSI-LD-Tenant: urn:ngsi-ld:tenant:default" | ...

Requête FROST (Thing.properties)

curl -s "http://localhost:8086/FROST-Server/v1.1/Things" | python3 -c "
import sys, json
data = json.load(sys.stdin)
for t in data.get('value', []):
    props = t.get('properties', {})
    print(f\"{t['name']} | source: {props.get('source')} | topic: {props.get('mqttTopic')}\")
"

Dernière mise à jour : 05 Mai 2026
Auteur : Smart City Digital Twin Team
Version : 1.1 (avec traçabilité source/mqttTopic)

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