The oneM2M Base Ontology …and how this matters to HGI

Source: Joerg Swetina (NEC) vicechair of oneM2M REQuirements group

joerg.swetina@neclab.eu

SDT from HGI

• HGI’s SDT (Smart Device Template) aims at a common approach for device modelling to enable interworking.

• SDT provides

– A set of automation commands,

– A common syntax,

sufficient to model most home appliance functions

https://github.com/Homegateway/SmartDeviceTemplate/

oneM2M Base Ontology

• oneM2M – like a HGI Smart Home Gateway – serves as an integration system that

– Enables interworking with external technologies

– Adds value (e.g. security, device management …)

• Instead of plain XML oneM2M uses ontologies (OWL) to describe the services, interfaces and functionalities from external technologies

– An ontology allows to: • Capture a shared understanding of a domain of interest.

• Provide a formal and machine manipulable model of the domain.

Why “ontology” ?

• Like SDT the oneM2M Base Ontology provides a template with very few essential concepts:

– A Thing: anything that can be described and identified in oneM2M

– A Device: special kind of Thing that can electronically communicate with other [oneM2M] entities. A non-oneM2M Device requires an Interworking Proxy for protocol translation

• has Services (and their functionality), DataPoints, Operations, Input / Output parameters

Device

The human-understandable

meaning The machine-

understandable

data-model

Some Base Ontology concepts

• Operation vs. Command

• Aspects, MetaData

• Things, ThingProperties, ThingRelations

A specific ontology is derived from the Base Ontology • Example: a standard KNX dimmer

– Functional Block – Dimming Actuator Basic (has been standardized). It contains KNX-DPTs:

• Switch, DPT 1.001

• Relative dimming, DPT 3.007

• Absolute dimming, DPT 5.001

Example: mapping KNX ontology into base ontology

“is-a” relationships of the “KNX ontology”

• A standard KNX dimmer is-a InterworkedDevice

• Functional Block “Dimming actuator basic” is-a Service

– “dimming-control” is-a Functionality (of that Service)

refers to an Aspect: “Electricity-Current”

• Operations – DPT 1.001

– DPT 3.007

– DPT 5.001

• Commands – Switch

– Relative Dimming

– Absolute Dimming MAS-2015-0618

Why “ontology” (…continued)

• Isn’t the base ontology just another kind of SDT? => Yes, but an ontology can do more:

• An ontology can be composed of multiple part- ontologies, e.g.

1. An ontology describing Devices, e.g. for home environment (sensors, actuators, controllers..)

2. An ontology describing Things, e.g. in a building (rooms, water pipes, electric outlets…)

• Together they can describe a complete system, including non-functional aspects (street, color..)

Why “ontology” (…)

• On oneM2M raw data can be ‘annotated’ – e.g. in RDF triple form – using a Semantic Descriptor that is based on an ontology.

– The Semantic Descriptor uses the vocabulary of the ontology to describe:

• the entity (e.g. a street in a smart city)

• entity relationship with other entities (e.g. connects to)

• The entirety of Semantic Descriptors can be searched, based on their meaning (SPARQL)

– E.g. find all streets with high CO2 concentration

Why “ontology” (…)

• Big Data processing, Analytics

– Highly improved by semantic description of data

• M2M service provider in the role of:

– Data broker

– Data re-seller

• E.g. anonymized

– Analytics provider

• Analytics in the edge

– System integrator

• “semantic connector”

Some challenges

• The world of semantics and the world of M2M are still at different levels

– Simple devices still provide just raw data, no semantic information

– In oneM2M the often data value needs to be fetched from a different place than its description.

– Semantic information is distributed. Discovery of semantics together with data values is complex, e.g.

• Find all sensors in a region XYZ that currently measure CO2-concentration with a value > 95

My expectations • HGI’s SDT initiative nicely harmonizes with the

oneM2M concept. It allows a simple way of providing technical information on devices.

• We need an ecosystem where manufacturers, experts and users are able to use a common terminology (=ontology) in a simple way.

• IoT will create “another type of Internet”, but this is a slow (not dramatic) process and requires much care by responsible people.