FIWARE Global Summit - NGSI-LD - NGSI with Linked Data

NGSI-LD – NGSI with Linked Data
Martin Bauer – NEC Laboratories Europe
José Manuel Cantera Fonseca – FIWARE Foundation
November 2018 (Aligned with ETSI ISG CIM)

2
‘Dealing’ with ‘Data’: 5 Star Model (W3C, Berners-Lee)
Open Data
The World Wide Web Consortium (W3C) has
developed a five star model to describe
different characteristics of open data, and its
usefulness for people wishing to reuse it. It is
being used globally as a model for assessing
data readiness for re-use.
The 3-star level is considered the minimum
standard for release of government’s public
data of single agencies for re-use.
The 4/5-star level is considered required
for multi-agency / multi-city scenarios
* Data is visible, licensed for reuse (CC), but requires considerable effort to reuse.
** Data is visible, licensed, and easy to reuse, but not necessarily by all.
*** Data is visible and easy to reuse by all (not restricted to using specific software).
**** Data is visible, easy to use and described (with meta data) in a standard fashion.
***** Data is visible, easy to use, described in a standard fashion and meaning is
clarified by being linked to a common definition (i.e. Ontology).

3
Proprietary
Data
Open
Data
A.I.
CONTEXT INFORMATION MANAGEMENT:
EXCHANGE DATA AND DEFINITIONS (ONTOLOGY)
User
Apps
IoT
Context
Information
Management
APPs
APPs
APPs
Provenance Usage
Context
Information
Ontologies
Context
Information
Ontologies
Context
Information
Ontologies
Context
Information
Ontologies
Context
Information
Ontologies
Context
Information
Ontologies
Context
Information
Ontologies
Context
Information
Ontologies
NGSI-LD
NGSI-LD
Source: ETSI ISG CIM

4
Standardizing NGSI-LD as Evolution of NGSI Context Interface Family
à ETSI Group Specification
Contact for ETSI ISG CIM:
Chairman: Lindsay Frost
ISGSupport@etsi.org
Open pages for consensus material:
https://docbox.etsi.org/ISG/CIM/Open
• visit at: https://portal.etsi.org/CIM
Timeframe:
• NGSI-LD v1.0 API Specification. Closed in December 2018
• UCs and other WIs beginning of 2019
ETSI INDUSTRY SPECIFICATION GROUP FOR CROSS-CUTTING
CONTEXT INFORMATION MANAGEMENT (ETSI ISG CIM)

5
CAN WE (OR YOU) „KEEP IT SIMPLE“ ?
ETSI ISG CIM NGSI-LD API FEATURES (+LIMITS)
Information Model is Graph-based & information-centric
• Core concepts include Entities and Relationships
• Entities can have Properties and Relationships
• Relationships/Properties can also have Properties, Relationships
Referencing of defined/hierarchical vocabularies/ontologies
• All terms are unambiguously defined
• Allows users to reference their familiar information definitions
Model and Query language (is constrained so more predictable)
• Federation of (independent) information sources, anywhere
• Queries: based on entity type or ID, can filter results, can constrain geographic scope,
constrained not to traverse graph (only one level at a time)

6
VARIOUS ARCHITECTURES POSSIBLE
Centralised Distributed Federated
Application
ETSI ISG CIM API
Simplicity

7
Application
More flexibility
ETSI ISG CIM API

8
Application
Integration of multiple Systems
ETSI ISG CIM API

Temporal Queries (e.g. for trend analysis)
Regular Query
“most recent”
GPS
Speedometer
Temporal Query
GPS
Speedometer
time time
included in result set
not included in result set
9

11
Information Model
Attributes
• Name
• Type
• Value
Entity
• EntityId
• EntityType
1 n
“has”
Metadata
• Name
• Type
• Value1 n
“has”
11

12
Information Model (as UML) – NGSI-LD

13
Information Model - Highlights
§ NGSI Entity à Physical or virtual object.
§ It has (one) Entity Type.
§ Uniquely identified by an Entity Id (URI)
§ Entity has zero or more attributes identified by a name
§ Property --> Static or dynamic characteristic of an entity
§ GeoProperty (geospatial context)
§ TemporalProperty (time context)
§ Relationship à Association with a Linked entity (unidirectional)
§ Properties have a value
§ An NGSI value can be a single value (Number, String, boolean), or complex (Array, Structured
Value)
§ Relationships have an object
§ A URI which points to another entity (target of the relationship). Target can be a collection.

14
Information Model – Highlights (II)
§ Cross-Domain, core properties for giving context to your information are
defined in a mandatory way, to be used by API operations (e.g. geo queries)
§ location à Geospatial location, encoded as GeoJSON.
§ observedAt à Observation timestamp, encoded as ISO8601. (timestamp)
§ createdAt à Creation timestamp (of entity, attribute). dateCreated in NGSIv2
§ modifiedAt à Update timestamp (of entity, attribute). dateModified in NGSIv2
§ unitCode à Units of measurement, encoded as mandated by UN/CEFACT.
§ Recommended practice
§ Use URIs to identify your entities.
§ A URN schema is provided off-the-shelf. It enables to know in advance what entity type
an id refers to
§ urn:ngsi-ld:<Entity_Type_Name>:<Entity_Identification_String>

15
Example
Source: ETSI Specification

17
Classical JSON Representation (a.k.a. NGSIv2)
{
"id": "urn:ngsi-ld:Vehicle:A4567",
"type": "Vehicle",
"brandName": {
"type": "Property",
"value": "Mercedes"
},
"isParked": {
"type": "Relationship",
"value": "urn:ngsi-ld:OffStreetParking:Downtown1",
"metadata": {
"observedAt": {
"value" : "2017-07-29T12:00:04Z",
"type" : "DateTime"
},
"providedBy": {
"type" : "Relationship",
"value" : "urn:ngsi-ld:Person:Bob"
}
}
}
}
{
"id": "urn:ngsi-ld:OffStreetParking:Downtown1",
"type": "OffStreetParking",
"availableSpotNumber": {
"type": "Property",
"value": 121,
"metadata" : {
"observedAt": {
"value" : "2017-07-29T12:00:04Z",
"type" : "DateTime"
},
"reliability": {
"type" : "Property",
"value" : 0.7
},
"providedBy": {
"type" : "Relationship",
"value" : "urn:ngsi-ld:Camera:C1"
}
}
},
"location": {
"type": "geo:json",
"value": {
"type": "Point",
"coordinates": [-8.5, 41.2]
}
}
}

18
JSON-LD (RDF friendly) representation (a.k.a. NGSI-LD)
{
"id": "urn:ngsi-ld:Vehicle:A4567",
"type": "Vehicle",
"brandName": {
"type": "Property",
"value": "Mercedes"
},
"isParked": {
"object": "urn:ngsi-ld:OffStreetParking:Downtown1",
"observedAt": "2017-07-29T12:00:04Z",
"providedBy": {
"object": "urn:ngsi-ld:Person:Bob"
}
},
"@context": [
"http://uri.etsi.org/ngsi-ld/coreContext.jsonld",
"http://example.org/cim/commonTerms.jsonld",
"http://example.org/cim/vehicle.jsonld",
"http://example.org/cim/parking.jsonld"
]
}
{
"availableSpotNumber": {
"type": "Property",
"value": 121,
"observedAt": "2017-07-29T12:05:02Z",
"reliability": {
"type": "Property",
"value": 0.7
},
"providedBy": {
"object": "urn:ngsi-ld:Camera:C1"
}
},
"location": {
"type": "GeoProperty",
"value": {
"type": "Point",
}
},
"@context": [
]
}

19
Simplified representation (keyValues)
{
"name": "Downtown One",
"availableSpotNumber": 121,
"totalSpotNumber": 200,
"location": {
"type": "Point",
},
"@context": [
]
}
Equivalent in NGSI-LD and NGSIv2

Query and Manage Temporal Information
§ Optional support for temporal functionality
§ Can be provided by General Broker or separate component
§ Example: Query on /temporal/entites
/temporal
/entities
/{entityId}
/attrs
/{attrId}
/{instanceId}
GET /ngsi-ld/temporal/entities/?type=Vehicle&q=brandName!=Mercedes&
attrs=speed,brandName&timerel=between&time=2018-08-01:12:00:00Z
&endTime=2018-08-01:13:00:00Z
{ "id": "urn:ngsi-ld:Vehicle:B9211",
"type": "Vehicle",
"brandName": [ {
"type": "Property",
"value": "Volvo",
}],
"speed": [{
"type": "Property",
"value": 120,
"observedAt": "2018-08-01T12:03:00Z"
},
{
"type": "Property",
"value": 100,
"observedAt": "2018-08-01T12:07:00Z"
}
],
"@context": [
"http://example.org/cim/vehicle.jsonld"
]}
21

28
Overall strategy / timeline
§ Principles
§ Avoid vendor lock-in, i.e. a standard that only has one implementation.
§ NGSI-LD <> FIWARE.
§ Multiple implementations will be beneficial for the FIWARE Ecosystem and NGSI-LD in the end
§ FIWARE Foundation stimulates the development of different implementations by
§ welcoming and supporting the existence of multiple implementations of NGSI-LD
§ contributing to a common test suite that can be used by implementors to verify their compliance
to the specification.
§ devoting some resources to the extension of Orion for supporting NGSI-LD,
§ supporting and encouraging other alternative or complementary implementation initiatives

29
Orion Context Broker – Next Steps
§ Plan
§ Evolve Orion to support NGSI-LD. First alpha (branched) version. Dec 2018.
§ During 2019 the integration with the main development branch will be done.
§ Full NGSI-LD support will take time.

30
NEC’s Roadmap
§ NEC is developing NGSI-LD Broker, alpha version ready
§ Show and evaluate
§ Distribution and federation aspects
§ Scalability
§ Modular architecture
§ Use it in NEC‘s research and innovation projects, in particular
§ Autopilot
§ Synchronicity
§ CPaaS.io
§ Fed4IoT
§ Deployment with City of Heidelberg
§ Alpha-version of NGSI-LD Broker will be made available to project partners in a
FIWARE sandbox environment soon (together with other FIWARE GEs).
§ NEC is going to support development of common FIWARE test suite for NGSI-LD
§ Further steps regarding integrating into FIWARE ecosystem are under discussion
Orion Context Broker instances
NEC
NGSI-LD
Broker
Applications
This activity has partially received funding by the European Commission
(Horizon 2020 grant agreement No. 723076 (CPaaS.io), No. 814918
(Fed4IoT), No. 731993 (Autopilot) and No. 732240 (SynchroniCity)

32
References
§ ETSI NGSI-LD Specification (April 2018)
§ http://www.etsi.org/deliver/etsi_gs/CIM/001_099/004/01.01.01_60/gs_CIM004v010101p.pdf
§ https://docbox.etsi.org/isg/cim/open/Presentation_for_WoT_Plenary_Meeting_Lyon__TPAC_.pdf
§ Additional specification resources
§ https://forge.etsi.org/gitlab/NGSI-LD/NGSI-LD
§ OAS Specification: https://forge.etsi.org/swagger/ui/?url=https://forge.etsi.org/gitlab/NGSI-
LD/NGSI-LD/raw/master/spec/updated/full_api.json
§ GAP Analysis FIWARE NGSIv2 <-> NGSI-LD
§ https://docs.google.com/spreadsheets/d/186QYvbRo2IlRdvJmjP9oKSsawrVey8-
A7ncRjBrzihw/edit#gid=0
§ https://github.com/Fiware/context.Orion-LD/wiki/Implementors-FAQ

33
References
§ NGSI-LD Wrapper (Proxy on top of Orion)
§ https://github.com/Fiware/NGSI-LD_Wrapper
§ NGSI-LD Test Suite
§ https://github.com/Fiware/NGSI-LD_Tests
§ FIWARE Orion Context Broker (LD branch)
§ https://github.com/fiware/context.Orion-LD (check branches)
§ docker run fiware/orion-ld

Thank you!
http://fiware.org
Follow @FIWARE on Twitter
José Manuel Cantera Fonseca
FIWARE Foundation
Josemanuel.cantera@fiware.org
Martin Bauer
NEC Laboratories Europe
martin.bauer@neclab.eu

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