Abbreviation | NGSI-LD |
---|---|
Status | ETSI Group Specification |
Year started | 2017 |
Organization | ETSI |
Authors | ISG CIM (Industry Specification Group) of ETSI |
Base standards | RDF, RDFS, OWL, JSON, JSON-LD, HTTP, URI |
Domain | Information model, linked data, semantic web |
Website | CIM group page @ETSI |
NGSI-LD is an information model and API for publishing, querying and subscribing to context information. It is meant to facilitate the open exchange and sharing of structured information between different stakeholders. It is used across application domains such as smart cities, [1] [2] [3] smart industry, smart agriculture, [4] [5] and more generally for the Internet of things, [6] cyber-physical systems, systems of systems [7] and digital twins. [8]
NGSI-LD has been standardized by ETSI (European Telecommunications Standardization Institute) through the Context Information Management Industry Specification Group, following a request [9] from the European Commission. Its takeup and further development are spelled out in the EU's "Rolling plan for ICT standardization". [10] NGSI-LD builds upon a decades-old corpus of research in context management frameworks and context modelling. [11] The acronym NGSI stands for "Next Generation Service Interfaces", a suite of specifications originally issued by the OMA which included Context Interfaces. [12] These were taken up and evolved as NGSIv2 [13] by the European Future Internet Public-Private-Partnership (PPP), which spawned the FIWARE open source community.
The NGSI-LD information model represents Context Information as entities that have properties and relationships to other entities. It is derived from property graphs, [14] with semantics formally defined on the basis of RDF and the semantic web framework. It can be serialized using JSON-LD. Every entity and relationship is given a unique IRI reference as identifier, making the corresponding data exportable as linked data datasets. The -LD suffix denotes this affiliation to the linked data universe.
The NGSI-LD information model [15] can be considered as the first formal specification by a de jure standards organization of the property graph model, which has emerged since the early 2000s as an informal common denominator model for graph databases.
The core concepts are:
The NGSI-LD meta-model [15] formally defines these foundational concepts (Entities, Relationships, Properties) on the basis of RDF/ RDFS/ OWL, and partially on the basis of JSON-LD.
Complementing this metamodel, the NGSI-LD information model specification also provides a cross-domain ontology [15] that defines key constructs related to spatial, temporal or system-composition characteristics of entities.
The flexible information model allows the specification of any kind of entity. In order to allow interoperability between NGSI-LD users, standardized entities are collaboratively defined at Smart Data Models Program and made available at its repository with an open-source license.
The NGSI-LD specification consists of an information model and an API. The API provides functionalities to support the architectural roles described in the following.
The architectural roles allow the implementation of different deployment architectures. In a centralized architectures, there is a central Context Broker that stores the context information provided by Context Producers. In a distributed setting, all context information can be stored by Context Sources. In a federated architecture, Context Sources can again be Context Brokers that make aggregated information from a lower hierarchy level available. These architectures are not mutually exclusive, i.e. an actual deployment may combine them in different ways.
The NGSI-LD Context Information Management API [16] allows users to provide, consume and subscribe to context information in multiple scenarios and involving multiple stakeholders. It enables close to real-time access to information coming from many different sources (not only IoT data sources), named Context Sources, as well as publishing that information through interoperable data publication platforms.
It provides advanced geo-temporal queries, and it includes subscription mechanisms, in order for content consumers to be notified when content matching some constraints becomes available.
The API is designed to be agnostic to the architecture (central, distributed, federated or combinations thereof), so that applications which produce and consume information do not have to be tailored to the specifics of the system that distributes/brokers context information for them.
API operations comprise:
NGSI-LD was initiated by partners of the FIWARE programme, and is primarily used by the FIWARE open source community, [17] supported by the FIWARE Foundation [18] as well as a diverse range of other projects and users such as below:
NGSI-LD is the result of an evolution of Context Interfaces that started as part of the "Next Generation Service Interfaces" (NGSI) suite published by the Open Mobile Alliance (OMA) in 2012, which is also the source of the acronym NGSI. The NGSI suite included NGSI-9 as the Context Entity Discovery Interface and NGSI-10 as the Context Information Interface. [12] The NGSI standard from OMA and its intermediary evolutions relied on a classical Entity–attribute–value model and an XML-based representation. The NGSI Context Interfaces were adapted by the FI-WARE project, which developed the platform for the European Future Internet Public-Private-Partnership (PPP). The OMA NGSI Context Interfaces got an HTTP binding with a JSON representation, referred to as NGSIv1, which included both NGSI-9 and NGSI-10. In the course of FI-PPP the interfaces further evolved into NGSIv2, [13] which became the key interface of the FIWARE platform. After the end of the FI-PPP in 2016, the FIWARE platform became the core of the FIWARE Open Source Community managed by the FIWARE Foundation. In 2017, the ETSI Industry Specification Group on cross-cutting Context Information Management (ETSI ISG CIM) was created to evolve the Context Information Interface, which resulted in the creation of NGSI-LD. The limitations of the original information model led to the specification of a broader model which derives from property graphs, explicitly including relationships between entities, on a par with entities themselves. ETSI ISG CIM continues to evolve the NGSI-LD Information Model and API. It publishes new versions of the specification once or twice a year.
p.6, In today's Smart Cities "System-of-Systems" architectures are created on the basis of the ETSI standard "Context Information Management (ETSI ISG CIM)" also known as NGSI-LD.
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: CS1 maint: multiple names: authors list (
link)
Abbreviation | NGSI-LD |
---|---|
Status | ETSI Group Specification |
Year started | 2017 |
Organization | ETSI |
Authors | ISG CIM (Industry Specification Group) of ETSI |
Base standards | RDF, RDFS, OWL, JSON, JSON-LD, HTTP, URI |
Domain | Information model, linked data, semantic web |
Website | CIM group page @ETSI |
NGSI-LD is an information model and API for publishing, querying and subscribing to context information. It is meant to facilitate the open exchange and sharing of structured information between different stakeholders. It is used across application domains such as smart cities, [1] [2] [3] smart industry, smart agriculture, [4] [5] and more generally for the Internet of things, [6] cyber-physical systems, systems of systems [7] and digital twins. [8]
NGSI-LD has been standardized by ETSI (European Telecommunications Standardization Institute) through the Context Information Management Industry Specification Group, following a request [9] from the European Commission. Its takeup and further development are spelled out in the EU's "Rolling plan for ICT standardization". [10] NGSI-LD builds upon a decades-old corpus of research in context management frameworks and context modelling. [11] The acronym NGSI stands for "Next Generation Service Interfaces", a suite of specifications originally issued by the OMA which included Context Interfaces. [12] These were taken up and evolved as NGSIv2 [13] by the European Future Internet Public-Private-Partnership (PPP), which spawned the FIWARE open source community.
The NGSI-LD information model represents Context Information as entities that have properties and relationships to other entities. It is derived from property graphs, [14] with semantics formally defined on the basis of RDF and the semantic web framework. It can be serialized using JSON-LD. Every entity and relationship is given a unique IRI reference as identifier, making the corresponding data exportable as linked data datasets. The -LD suffix denotes this affiliation to the linked data universe.
The NGSI-LD information model [15] can be considered as the first formal specification by a de jure standards organization of the property graph model, which has emerged since the early 2000s as an informal common denominator model for graph databases.
The core concepts are:
The NGSI-LD meta-model [15] formally defines these foundational concepts (Entities, Relationships, Properties) on the basis of RDF/ RDFS/ OWL, and partially on the basis of JSON-LD.
Complementing this metamodel, the NGSI-LD information model specification also provides a cross-domain ontology [15] that defines key constructs related to spatial, temporal or system-composition characteristics of entities.
The flexible information model allows the specification of any kind of entity. In order to allow interoperability between NGSI-LD users, standardized entities are collaboratively defined at Smart Data Models Program and made available at its repository with an open-source license.
The NGSI-LD specification consists of an information model and an API. The API provides functionalities to support the architectural roles described in the following.
The architectural roles allow the implementation of different deployment architectures. In a centralized architectures, there is a central Context Broker that stores the context information provided by Context Producers. In a distributed setting, all context information can be stored by Context Sources. In a federated architecture, Context Sources can again be Context Brokers that make aggregated information from a lower hierarchy level available. These architectures are not mutually exclusive, i.e. an actual deployment may combine them in different ways.
The NGSI-LD Context Information Management API [16] allows users to provide, consume and subscribe to context information in multiple scenarios and involving multiple stakeholders. It enables close to real-time access to information coming from many different sources (not only IoT data sources), named Context Sources, as well as publishing that information through interoperable data publication platforms.
It provides advanced geo-temporal queries, and it includes subscription mechanisms, in order for content consumers to be notified when content matching some constraints becomes available.
The API is designed to be agnostic to the architecture (central, distributed, federated or combinations thereof), so that applications which produce and consume information do not have to be tailored to the specifics of the system that distributes/brokers context information for them.
API operations comprise:
NGSI-LD was initiated by partners of the FIWARE programme, and is primarily used by the FIWARE open source community, [17] supported by the FIWARE Foundation [18] as well as a diverse range of other projects and users such as below:
NGSI-LD is the result of an evolution of Context Interfaces that started as part of the "Next Generation Service Interfaces" (NGSI) suite published by the Open Mobile Alliance (OMA) in 2012, which is also the source of the acronym NGSI. The NGSI suite included NGSI-9 as the Context Entity Discovery Interface and NGSI-10 as the Context Information Interface. [12] The NGSI standard from OMA and its intermediary evolutions relied on a classical Entity–attribute–value model and an XML-based representation. The NGSI Context Interfaces were adapted by the FI-WARE project, which developed the platform for the European Future Internet Public-Private-Partnership (PPP). The OMA NGSI Context Interfaces got an HTTP binding with a JSON representation, referred to as NGSIv1, which included both NGSI-9 and NGSI-10. In the course of FI-PPP the interfaces further evolved into NGSIv2, [13] which became the key interface of the FIWARE platform. After the end of the FI-PPP in 2016, the FIWARE platform became the core of the FIWARE Open Source Community managed by the FIWARE Foundation. In 2017, the ETSI Industry Specification Group on cross-cutting Context Information Management (ETSI ISG CIM) was created to evolve the Context Information Interface, which resulted in the creation of NGSI-LD. The limitations of the original information model led to the specification of a broader model which derives from property graphs, explicitly including relationships between entities, on a par with entities themselves. ETSI ISG CIM continues to evolve the NGSI-LD Information Model and API. It publishes new versions of the specification once or twice a year.
p.6, In today's Smart Cities "System-of-Systems" architectures are created on the basis of the ETSI standard "Context Information Management (ETSI ISG CIM)" also known as NGSI-LD.
{{
cite web}}
: CS1 maint: multiple names: authors list (
link)