[WoT+NGSI-LD] minutes - 17 February 2025

available at:
  https://www.w3.org/2025/02/17-wot-ngsi-ld-minutes.html


also as text below.

Please note that the meeting on Feb 24 will be cancelled and
the next meeting will be held on March 3.

Kazuyuki

---
   [1]W3C

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


                             – DRAFT –
                            WoT and NGSI-LD

17 February 2025

   [2]Agenda. [3]IRC log.

      [2] https://www.w3.org/WoT/IG/wiki/WoT-NGSI-LD#February_17,_2025

      [3] https://www.w3.org/2025/02/17-wot-ngsi-ld-irc


Attendees

   Present
          Franck_Le_Gall, Juanjo_Hierro, Kaz_Ashimura,
          Ken_Zangelin, Martin_Bauer, Michael_McCool, Zane_Durkin

   Regrets
          -

   Chair
          McCool

   Scribe
          kaz

Contents

    1. [4]Minutes
    2. [5]Cancellations
    3. [6]Activities
         1. [7]Resources
    4. [8]Other issues and PRs
    5. [9]AOB

Meeting minutes

  Minutes

   [10]Feb-3

     [10] https://www.w3.org/2025/02/03-wot-ngsi-ld-minutes.html


   McCool: (goes through the minutes)

   typos fixed; approved

  Cancellations

   McCool: cancellation on Feb 24
   … the next meeting will be March 3
   … we can keep the meeting weekly but can cancel the meeting if
   people are not available

  Activities

    Resources

   [11]resources.md

     [11] https://github.com/w3c/wot-ngsi-ld/blob/main/resources.md


   McCool: I've been reading the NGSI-LD spec
   … basically, NGSI-LD discover the database
   … what is interesting is that WoT Directory also finds the TD
   as the database
   … so very similar design with each other

   Martin: we have open APIs

   <martin> NGSI-LD OpenAPI is available here: [12]https://
   forge.etsi.org/rep/cim/ngsi-ld-openapi

     [12] https://forge.etsi.org/rep/cim/ngsi-ld-openapi


   McCool: ok
   … the difference from my viewpoint is
   … the WoT Discovery is very simple
   … we can get Thing Description, which is JSON-LD
   … what would be the technical requirements?
   … 1. context management
   … we can use nested contents

   McCool: wondering about the compatibility
   … 2. TD using special Things
   … one of those is default values
   … normalize the TD to formalize the data

   Ken: we also have default values too

   Martin: but maybe a bit different level...
   … we use JSON-LD as representation
   … what is our structure looks like

   McCool: default value is just one example
   … we should investigate the differences

   McCool: a set of nodes to be included

   <martin> JSON-LD is a serialization of RDF (as abstract model)
   - RDF/XML is another serialization of RDF

   Juanjo: definitely interesting
   … digital twin characteristics
   … we could generate TD based o the TM template
   … have to discuss the digital twin class

   McCool: TD describes entities
   … could be a digital twin
   … what TDs bring to the table include data modeling languages
   … describing the payload
   … also describe affordance, i.e., property, action and event

   Kaz: tx for your investigation, McCool
   … we should now start to describe what is done one the NGSI-LD
   side and what on the WoT side
   … based on some concrete use case
   … to clarify what the NGSI-LD broker and the WoT Directory do
   there

   McCool: yeah
   … we should capture the use cases based on our understandings

   [13]Issue 8 - Capture Use Cases

     [13] https://github.com/w3c/wot-ngsi-ld/issues/8


   <jhierro7> This presentation brought the idea I had commented:

   <jhierro7> [14]https://docs.google.com/presentation/d/

   1-RI8q1hhnRqaZDwvxnpKnaaxQ0kMGtME/
   edit?usp=sharing&ouid=115453639179713725602&rtpof=true&sd=true

     [14] https://docs.google.com/presentation/d/1-RI8q1hhnRqaZDwvxnpKnaaxQ0kMGtME/edit?usp=sharing&ouid=115453639179713725602&rtpof=true&sd=true


   McCool: should add a link for that also to the resources.md

   Juanjo: also a PR to add that to the resource.md

   [15]PR 9 - Adding presentation in section about Presentations

     [15] https://github.com/w3c/wot-ngsi-ld/pull/9


   McCool: (merged)
   … (shows slide 7. Compatibility of NGSI-LD with Thing
   Models/Descriptions)
   … (also slide 12. Compatibility of NGSI-LD with Thing
   Descriptions)

   Juanjo: another PR about the idea of TM as template

   [16]PR 10 - Update section on Thing Models as Templates

     [16] https://github.com/w3c/wot-ngsi-ld/pull/10


   McCool: (merged)
   … let's think about the next steps now

   [17]example/README.md

     [17] https://github.com/w3c/wot-ngsi-ld/blob/main/examples/README.md


   McCool: (shows examples/README.md)
   … would create a new Issue to document technical gaps
   … (adds questions)
   … Does "type" abstraction in NGSI-LD map onto the ability of
   TMs to describe classes of potential TD instances?
   … TMs used for describing the properties of entity types?
   … conceptually, TMs describe classes
   … note that TM doesn't have network interface

   McCool: What is the subclass structure?
   … TMs for everything or for subclasses of "entities with
   affordances/network interfaces"?

   Juanjo: TM describes what to be exposed

   McCool: technically, TM is a class of template
   … but it's a templating mechanism
   … (revisits the 3 questions issued within the GitHub Issue)
   … (and adds another question)

   <jhierro7> In my view, Things Model templates allow to describe
   the characteristics of any instance of an entity type (Things
   class if you want)

   <jhierro7> Things Description can be derived from those
   templates, by adding forms how those characteristics can be
   accessed using specific protocols.

   McCool: Should TMs/TDs we attached as annotations or be
   included in the NGSI-LD type structure?

   <jhierro7> In such case, TM can be used to describe
   characteristics of Things = Entity Types

   <jhierro7> and then, we may specify how TDs can be derived
   where NGSI-LD is added as form to access characteristics

   McCool: TMs may so be more "dynamic" than (what seem to be) the
   pre-defined "types" used by NGSI-LD
   … would like to understand what is possible at the moment

   Kaz: some discussion about how to generate TD instance from TM
   last week during the TD call
   … this discussion about TM and NGSI-LD should be useful for
   that (=TM vs TD) discussion also
   … so would suggest we clarify our expectation for TM a bit more

   McCool: yeah, we should have more discussion
   … let's add the link about the discussion from the TD TF too

  Other issues and PRs

   [18]Remaining Issues

     [18] https://github.com/w3c/wot-ngsi-ld/issues


   [19]Remaining PRs

     [19] https://github.com/w3c/wot-ngsi-ld/pulls


   Juanjo: would like to work on some more exercise

   McCool: let's take a few TMs/TDs and NGSI-LDs to see the
   differences

   <jhierro7> The exercise of taking an entity type description
   using the WoT Models Template, and show how Thing Descriptions
   can be derived using NGSI-LD as form.

   <jhierro7> (form for access)

   McCool: Review and comment on new issues
   … Test importing TDs into NGSI-LD broker
   … Generate a concrete example of using TM/TDs for Digital Twin
   modelling

  AOB

   McCool: next meeting on March 3
   … will update the agenda
   … we'll keep the meeting as weekly
   … but will send a cancellation notifications based on the
   actual schedule

   [adjourned]


    Minutes manually created (not a transcript), formatted by
    [20]scribe.perl version 242 (Fri Dec 20 18:32:17 2024 UTC).

     [20] https://w3c.github.io/scribe2/scribedoc.html

Received on Monday, 17 February 2025 17:06:19 UTC