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[TF-LD] minutes - 14 September 2018

From: Kazuyuki Ashimura <ashimura@w3.org>
Date: Mon, 17 Sep 2018 16:36:07 +0900
Message-ID: <CAJ8iq9WFx1FNa-J9ZS9tDymmtzNHThv9LkYvRQ4MOSdY9CpeRQ@mail.gmail.com>
To: Public Web of Things IG <public-wot-ig@w3.org>
available at:

also as text below.

Thanks for taking the minutes, Danh!




      [1] http://www.w3.org/

                               - DRAFT -

                             WoT IG - LD-TF

14 Sep 2018


          Darko_Anicic, Lindsay_Frost, Kaz_Ashimura,
          Danh_Le_Phuoc, Maria_Poveda, Michael_Koster,



          DanhLePhuoc, kaz


     * [2]Topics
         1. [3]Interoperability between NGSI-LD Information Model
            and WoT TD model/iot.schema.org
     * [4]Summary of Action Items
     * [5]Summary of Resolutions

Interoperability between NGSI-LD Information Model and WoT TD

   <DarkoAnicic> [6]Lindsay's slides

      [6] https://docbox.etsi.org/ISG/CIM/Open/CIM(18)000174r1_NGSI-LD_compared_to_WoT_20180829.pdf

   <inserted> scribenick: kaz

   Lindsay: goes through the slides starting with p11
   ... [example: entity "vehicle" and its context in NGSI-LD]
   ... based on json-ld
   ... [p13: WoT: Thing Descriptions (LINK)]
   ... [p15: WoT Examples 2: Thing Description as JSON-LD 1.1
   ... data models for various connectivities with industry
   ... "writable" for putting information to devices
   ... "actions" and "events" as well
   ... would like to see the usage

   Darko: are you familiar with our definition of "events" and

   Lindsay: maybe Martin is

   Martin: yes

   Darko: representing the current state
   ... and then use actions for kind of changing the internal
   ... not obviously visible from outside but can be changed

   <inserted> scribenick: DanhLePhuoc

   Darko: we actions to change a couple of properties
   ... events are used to notify the changes

   Martin: our assumption is a bit of information-centric
   ... we're implementing our interfaces to focus on data

   Lindsay: rather than information/data on lower level services
   ... the sensor level can be done as well...

   Darko: do you assume that you only read information from the
   gateway or also writing as well?

   Martin: we can query the data but we can do other way around...

   Martin: it's up the endpoints to do the great thing

   Koster: it sounds like in the scope to what we are doing?

   Lindsay: we assume that concepts/units can be pointed to
   ... regarding to specific entity, we use uri..., then we
   describe the relationships among them
   ... regarding WoT, we can use proxies to routing messages...
   ... we expect all kinds of systems, legacy, database, ...etc
   ... that they can push messages to the system...

   <inserted> mjkoster: if we use zigbee-based light ball, etc.,
   would the connection with your system via oneM2M?

   Lindsay: we need to understand WoT TD to see how to integrate
   with oneM2M

   (Danh has trouble with audio connection, and Kaz takes over the

   <kaz> scribenick: kaz

   Darko: we have some proxy
   ... would it make sense to see what standard connect your NGSI
   system and provide services?
   ... what would make sense?

   Martin: how reasonable to explore?
   ... we work for TD and NGSI resources
   ... could be explored
   ... the other way around could be making assumption of
   specifying something
   ... general translation model
   ... at the moment don't have a good idea

   Koster: you have an information model
   ... could be done by semantic annotation from our viewpoint
   ... TD translates to your model

   Martin: exactly
   ... you're allowing semantic annotation
   ... what kind of data we can get from devices
   ... then we could make some bridge
   ... there is no way you can create NGSI model directly
   ... if I have the information, we can translate it using
   semantic annotation to get reasonable translation results

   Koster: TD has the whole annotation mechanism
   ... iot.schema is external schema mechanism
   ... iot.schema would like to provide small set of definitions
   ... few simple relation types
   ... we can refer to other ontologies for industry details,
   e.g., GENIVI for automotive
   ... other semantic connectors for other concepts could also be
   get from outside
   ... so we would like to do this based on a 2-layer model

   Lindsay: same as us
   ... starting with a different point, though

   Martin: do we have any resources?

   Darko: TD Editor's draft includes some examples

   Example 19: MyLampThing with semantic annotations based on a
   valid JSON-LD 1.1 representation
     "@context": ["[7]http://www.w3.org/ns/td",
       {"iot": "[8]http://iotschema.org/"}],
     "@type" : "Thing",
     "id": "urn:dev:wot:com:example:servient:lamp",
     "name": "MyLampThing",
     "description" : "MyLampThing uses JSON-LD 1.1 serialization",
     "security": [{"scheme": "psk"}],
     "properties": {
       "status": {
         "@type" : "iot:SwitchStatus",
         "description" : "Shows the current status of the lamp",
         "writable": false,
         "observable": false,
         "type": "string",
         "forms": [{
           "href": "coaps://mylamp.example.com/status",
           "mediaType": "application/json"

      [7] http://www.w3.org/ns/td
      [8] http://iotschema.org/

   Lindsay: why do you have "observable" as false here?

   Koster: observable means asynchronous event generation
   ... a bit different from "can be observed", etc.

   Lindsay+Martin: ok

   Koster: some more comprehensive examples as well

   <DarkoAnicic> FESTO TD:

      [9] https://github.com/w3c/wot/blob/master/plugfest/2018-bundang/TDs/Siemens/FestoLive.jsonld

   <DarkoAnicic> Siemens example:

     [10] https://github.com/w3c/wot/blob/master/plugfest/2018-bundang/TDs/Siemens/FestoLive.jsonld

   <kaz> Panasonic example:

     [11] https://github.com/w3c/wot/blob/master/plugfest/2018-bundang/TDs/Panasonic/airConditioner_p1.jsonld

   Darko: goes through the Siemens example above
   ... capability of pump
   ... like "PumpStatus"
   ... you see "festoPA" which is another ontology


     [12] https://github.com/w3c/wot/tree/master/plugfest/2018-bundang/TDs/Siemens

   Darko: it's currently just an example, though

   Lindsay: ok

   Darko: we explain the capability of pump using this
   "properties" notation
   ... also "Tank102LevelValue" capability below

   Koster: here you can get the instance of tank
   ... what the equipment is like
   ... also what the tank would do

   Martin: ok

   Lindsay: we'll take a look at those examples

   Martin: we'll have our meeting next week, so quite busy now

   Lindsay: goes back to ETSI slides
   ... [p19: Information Model]
   ... you should be able to do query and monitor the relationship
   ... the spec is nearly done
   ... and would like to similar systems

   Koster: was wondering
   ... your use of RDF is different from our usage
   ... interesting observation

   Martin: we have base model
   ... and different level models

   Lindsay: this week Open GSI had a meeting
   ... observation space and coordinate space for geoJSON
   ... absolutely minimum model to be defined
   ... we could rely on other standards instead of our own
   ... we want to know about reliability
   ... when to get modified, etc.
   ... for error correction, etc.
   ... systems should work without interoperability issues

   Darko: tx
   ... we had a bit more detailed discussion than the one during
   the main call
   ... interoperability between different ecosystems
   ... definition over abstraction layer

   Lindsay: if we can relatively easy import/export
   ... maybe we could use the same ontology commonly

   Darko: right

   Lindsay: we could start from iot.schema rather than from

   Kaz: we identified that both ETSI ISG CIM and W3C use layered
   ... and refer to external ontologies/schemas for actual

   Lindsay: we should keep in touch and continue discussion

   Darko: if you need some additional information, please drop us
   ... thanks very much for the discussion
   ... talk with you in 2 weeks

   Lindsay: wondering about Open GSI work

   Darko: we're aware of that work
   ... esp. Danh Le Phuoc

   Koster: SSN workshop in October in California

   Lindsay: thank you very much for giving us time!


Summary of Action Items

Summary of Resolutions

   [End of minutes]

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