After the Release 3 version of the oneM2M base ontology (version 3.6.0) had been finalized in TS-0012, the BO_SAREF.owl file in this directory gives an example how it can be used in practice. As a natural candidate for that exercise SAREF (Smart Appliances Reference Ontology) has been chosen.
The attached BO_SAREF.owl file imports both ontologies through reference:
It contains sub-classing and sub-Properties relationships between SAREF and the oneM2M base ontology. By creating this sub-classing and sub-Properties relationships all SAREF classes (and any potential sub-class of SAREF classes) can be istantiated as oneM2M resources, using the instantiation rules in TS-0012 and TS-0030.
Not all classes / properties of SAREF could be described as sub-classes / sub-properties of base ontology (BO) classes / properties.
In most cases this is not an issue, since all classes / properties of SAREF indeed can be implemented as RDF data in \<semanticDescriptor\> resources, using the rules of TS-0012.
However, in oneM2M Solutions, that do not make use of \<semanticDescriptor\> resources, SAREF (or SAREF based) ontologies, devices and their services can still be instantiated with oneM2M resources, using TS-0030 as mapping rule.
Devices, Input/output datapoints can be implemented, however some other semantic information might be lost.
Problems found, but not yet resolved:
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A particular problem arose with "saref:Property ". SAREF uses this class sometimes as classification:
- Device SubClassOf :IsUsedFor only (:BuildingObject or :Commodity or :Property)
Where "saref:Property " has sub-classes saref:Energy, saref:humidity, saref:Power, …
Sometimes SAREF uses this "saref:Property " class as in/output parameters of services.
- saref:Service SubClassOf :hasOutputParameter only (:Property or :State)
This seems to be an inconsistent use of "saref:Property " in SAREF and makes the sub-classing difficult.
Another problem was found in the oneM2M base ontology (BO) itself:
The problem relates to the mapping of information contained in instances of "BO:Aspect" (e.g. the quality or kind of a BO:Variable) and " BO:MetaData" (e.g. measurement units) into oneM2M resources (\<container\>s or \<flexContainer\>s). The problem arises only for oneM2M Solutions, that do not make use of \<semanticDescriptor\> resources.
The input/output parameters of a device (classes BO:Input/OutputDataPoint and BO:OperationInput/Output) and the properties of a thing (class " BO:ThingProperty") are derived from class " BO:Variable". Currently the class " BO:Variable" is related to classes " BO:Aspect" and " BO:MetaData" via relations (i.e. object properties):
- A " BO:Variable" " BO:describes" an " BO:Aspect"
- A " BO:Variable" " BO:hasMetaData" " BO:MetaData"
"Aspect" and "MetaData" are also related via:
- An " BO:Aspect" " BO:hasMetaData" " BO:MetaData"
While TS-0030 specifies how input/output parameters of a service of a device are instantiated as customAttributes of \<flexContainer\> service resources of the resource it does not specify how " BO:Aspect" and " BO:MetaData" should be instantiated.
According to section 7.1.1.2 of TS-0012 the resource types for instantiating these two should be the \<semanticDescriptors\>s of some \<container\> or \<flexContainer\>. The \<semanticDescriptor\> of the input/output parameters of a service contain the information where the \<semanticDescriptors\>s of " BO:Aspect" and " BO:MetaData" can be found.
If no \<semanticDescriptors\>s exist " BO:Aspect" and " BO:MetaData" can still be instantiated as \<container\> or \<flexContainer\>, however the linking between input/output parameter " BO:Variables" and related " BO:Aspect" and/or " BO:MetaData" is not specified.
This remains to be solved in the future.
The following tables give an overview on sub-classing and sub-Properties relationships contained in BO_SAREF.owl:
**Classes:**
|SAREF Class|Is subClassOf Base Ontology Class|Comment|
|-------|-----------|--------------------|
saref:BuildingObject|BO:ThingProperty|subClass relationship implemented in BO_SAREF
saref:BuildingSpace|BO:Thing|subClass relationship implemented in BO_SAREF
saref:Command|BO:Command|subClass relationship implemented in BO_SAREF
saref:Commodity|BO:ThingProperty|subClass relationship implemented in BO_SAREF
saref:Device|BO:Device|subClass relationship implemented in BO_SAREF
saref:DeviceCategory|BO:ThingProperty|subClass relationship implemented in BO_SAREF
saref:Function|BO:Function|subClass relationship implemented in BO_SAREF
saref:FunctionCategory|BO:Aspect|subClass relationship implemented in BO_SAREF
saref:Profile|BO:Thing|subClass relationship implemented in BO_SAREF
saref:Property| |No subClass relationship implemented in BO_SAREF. -Could be mapped to "BO:Aspect" when used as: saref:SensingFunction SubClassOf saref:hasSensingRange some saref:Property Or mapped to "BO:Variable" when used as: saref:Service SubClassOf saref:has[In/Out]putParameter only (saref:Property or saref:State) Or mapped to "BO:ThingProperty" (i.e. a subclass of "BO:Variable"), when used as: saref:Device SubClassOf saref:IsUsedFor only (saref:BuildingObject or saref:Commodity or saref:Property) Or as: saref:Profile SubClassOf saref:hasProduction only (saref:Energy or saref:Power) and saref:Profile SubClassOf saref:hasConsumption only (saref:Energy or saref:Power)
saref:Service|BO:Service|subClass relationship implemented in BO_SAREF
saref:State|BO:Variable|subClass relationship implemented in BO_SAREF
saref:Task|BO:ThingProperty|subClass relationship implemented in BO_SAREF
saref:UnitOfMeasure|BO:MetaData|subClass relationship implemented in BO_SAREF
**Object Properties:**
|SAREF Object Property|Is subPropertyOf Base Ontology Object Property|Comment|
|---|---|---|
saref:hasCategory|BO:hasThingProperty|subProperty relationship implemented in BO_SAREF
saref:accomplishes|BO:hasThingProperty|subProperty relationship implemented in BO_SAREF
saref:actsUpon|Inverse of: BO:exposesCommand|subProperty relationship implemented in BO_SAREF In BO an Input/OutputDataPoint or an Operation of a Service exposes a Command =\> In SAREF " saref:State " seems to be the counterpart to BO: Input/OutputDataPoint. saref:Command SubClassOf saref:actsUpon only saref:State =\>Note: there exists no concept of an "Operation" in SAREF!
saref:consistsOf| |No subProperty relationship implemented in BO_SAREF Either "BO:consistsOf " when used among devices as: saref:Device SubClassOf saref:consistsOf only saref:Devic Or " BO:hasThingRelation " when used among Profiles as: saref:Profile SubClassOf saref:consistsOf only saref:Profile
saref:contains|BO:hasThingRelation|subProperty relationship implemented in BO_SAREF
saref:hasCommand|BO:hasCommand|subProperty relationship implemented in BO_SAREF
saref:hasConsumption|BO:hasThingProperty|subProperty relationship implemented in BO_SAREF
saref:hasFunction|BO:hasFunction|subProperty relationship implemented in BO_SAREF
saref:hasInputParameter|BO:hasInputDataPoint|subProperty relationship implemented in BO_SAREF Because saref:Property and saref:State are mapped to BO:Variable (which is parent of BO:InputDataPoint) Note: saref:Service SubClassOf saref:hasInputParameter only (saref:Property or saref:State) =\>Note: there exists no concept of an "Operation" in SAREF!
saref:hasMeterReadingTime| |No subProperty relationship implemented in BO_SAREF ??? unclear in SAREF ?? This and the next SAREF property defines a relation between a saref:Function and a saref:Property, which is mapped to BO:Variable. saref:MeteringFunction SubClassOf saref:hasMeterReadingTime min 1 saref:Time (which is a saref:Property) In the Base Ontology a BO:Function has BO:Commands but no Variables
saref:hasMeterReadingValue| |No subProperty relationship implemented in BO_SAREF ??? unclear in SAREF ??? saref:MeteringFunction SubClassOf saref:hasMeterReadingValue only (saref:Commodity or saref:Property) Wouldn't a Function have a Command which would actUpon a state. The state would then have a value and a time
saref:hasOutputParameter|BO:hasOutputDataPoint|subProperty relationship implemented in BO_SAREF See: saref:hasInputParameter
saref:hasPrice|BO:hasThingProperty|subProperty relationship implemented in BO_SAREF
saref:hasProduction|BO:hasThingProperty|subProperty relationship implemented in BO_SAREF
saref:hasProfile|BO:hasThingRelation|subProperty relationship implemented in BO_SAREF
saref:hasSensingRange| |No subProperty relationship implemented in BO_SAREF Because mapping of saref:Property is unclear e.g. saref:SensingFunction SubClassOf saref:hasSensingRange some saref:Property
saref:hasSensingTime| |No subProperty relationship implemented in BO_SAREF Because mapping of saref:Property is unclear
saref:hasState|BO:hasThingProperty|subProperty relationship implemented in BO_SAREF saref:Device SubClassOf saref:hasState only saref:State (saref:State is mapped into BO:Variable)
saref:hasThreshold| |No subProperty relationship implemented in BO_SAREF
saref:hasTime|BO:hasThingProperty|subProperty relationship implemented in BO_SAREF
saref:hasTypicalConsumption|BO:hasThingProperty|subProperty relationship implemented in BO_SAREF
saref:isAccomplishedBy|Inverse of: BO:hasThingProperty|subProperty relationship implemented in BO_SAREF See: saref:accomplishes
saref:isCategoryOf|Inverse of: BO:hasThingProperty|subProperty relationship implemented in BO_SAREF See: saref:hasCategory
saref:isCommandOf|Inverse of: BO:hasCommand|subProperty relationship implemented in BO_SAREF See: saref:hasCommand
saref:isLocatedIn|BO:hasThingRelation|subProperty relationship implemented in BO_SAREF
saref:isMeasuredIn|BO:describes|subProperty relationship implemented in BO_SAREF
