[WoT+NGSI-LD] minutes - 10 March 2025

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


also as text below.

Thanks a lot for taking notes, Michael Koster!

Kazuyuki

---
   [1]W3C

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


                             – DRAFT –
                            WoT and NGSI-LD

10 March 2025

   [2]Agenda. [3]IRC log.

      [2] https://www.w3.org/WoT/IG/wiki/WoT-NGSI-LD#March_10,_2025

      [3] https://www.w3.org/2025/03/10-wot-ngsi-ld-irc


Attendees

   Present
          Dave_Raggett, Franck_LE_GALL, Frederic_LE, Kaz_Ashimura,
          Martin_Bauer, Michael_Koster, Michael_McCool

   Regrets
          -

   Chair
          McCool

   Scribe
          mjk

Contents

    1. [4]Minutes review
    2. [5]Review Proposed Use Cases
         1. [6]McCool's Use Case
         2. [7]Martin's Use Case
    3. [8]AOB

Meeting minutes

  Minutes review

   <kaz> [9]Mar-3

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


   McCool: working on use cases

   Martin: also working on use cases

   McCool: any objection to publish?
   … no objection, approved

  Review Proposed Use Cases

    McCool's Use Case

   <kaz> [10]PR 14 - Define Onboarding Use Case example

     [10] https://github.com/w3c/wot-ngsi-ld/pull/14

   McCool: PR #14 Defining onboarding use case

   McCool: this PR review can be used to agree on a template

   McCool: (review the use case md document in the examples
   directory)

   <kaz> [11]rendered MD

     [11] https://github.com/w3c/wot-ngsi-ld/blob/b680316fe2dc801d41ecc2928a44b3b6a00009b4/examples/onboarding.md


   McCool: the format includes a user story: as a (stakeholder) I
   need (a feature) so that I can (do something of value) , in
   other words who-what-why
   … also includes a section for design alternatives and a section
   for applications

   McCool: (refactoring the document headings)
   … how does it look now?

   Martin: looks OK

   <kaz> [12]updated MD

     [12] https://github.com/w3c/wot-ngsi-ld/blob/d0452640b140d95fb758f19144f3cf74f253449e/examples/onboarding.md


   McCool: (explain the use case)

   McCool: how can we import TDs and use them?
   … the primary use case is to describe devices and services
   … TDs are linked data; it's important to re-export TDs
   (northbound API)
   … We will use TDs to onboard devices
   … there are 3 options here
   … one is direct graph extension, what is the root of the
   extended graph?
   … another option is to translate TDs into a more suitable
   format for the graph
   … yet another option is through RDF annotation of the TD for
   connecting the TD to the graph as properties of nodes - similar
   to option one

   McCool: ... an example use case is getting real time data from
   a temperature sensor in a lake
   … are there any changes or additions we should make?

   Martin: the template is fine, the detailed assumptions need
   further review and discussion
   … we need to look at options 1 and 3 for potential mismatch

   McCool: there are some details we need to prepare detailed
   examples

   Martin: the question is how NGSI-LD and TD relate, where
   NGSI-LD is a description of the thing (the lake) and the
   temperature (a property) and the TD could be used as a method
   for obtaining the value of the property
   … we can't just add arbitrary RDF to the graph, so TDs are not
   a good fit like option one
   … Option 3 needs some working out
   … maybe there is a conceptual problem with the use case

   Martin: what is a thing and what is a Thing Description?

   McCool: physical things and software services can be Things in
   WoT

   Martin: how do we then map that into the NGSI-LD world

   McCool: there can be non-device entities in NGSI-LD

   Martin: maybe entities don't represent network devices

   McCool: at the high level example, I want to locate a
   temperature value onto a map
   … NGSI-LD and WoT do different things, and we want to bring
   them together, the question is how do they connect

   Kaz: the discussion is a good direction, for further discussion
   we should determine what kind of devices and entities we are
   looking at, some specific entities and devices

    Martin's Use Case

   <kaz> [13]Issue 15 - Use Case: Thing Description for Thing
   using NGSI-LD API

     [13] https://github.com/w3c/wot-ngsi-ld/issues/15


   Martin: this use case is about the northbound API
   … what would a TD look like to describe how to access the
   thing?

   McCool: if you already have an affordance to an entity, the TD
   would describe how to use the affordance

   Martin: need to construct an example TD, how do I map the
   NGSI-LD operations in the TD?
   … how to use the HTTP binding with JSON-LD content
   … We map Properties to NGSI-LD Attributes
   … there is an issue in that the API currently returns an entire
   set of Attributes
   … We always send full JSON-LD documents in responses
   … There may be a Patch interface possible

   McCool: another option (2 above) would define a whole new API
   to mitigate the conceptual differences
   … a layer to translate concepts

   McCool: we should do a detailed design

   Martin: not clear how links and relationships are used
   … we don't have actions per se, use updates of Attributes
   … looking into Service Execution, which is more easily mapped
   to TD Actions
   … looking at how to make Service Execution more like TD Actions
   … for Events, we have Subscriptions which may map to TD Events

   McCool: Events and Actions are not described in detail in TD
   … but we do have Profiles that can be used to refine the
   mechanisms

   Kaz: suggest that we clarify what specifically, Entities,
   Things, Services, Applications, etc., is being mapped from
   NGSI-LD to TD

   McCool: we are running out of time, so everyone add comments to
   the issue
   … also add more use cases now that we have more of a template

   McCool: The use cases should correspond to northbound and
   southbound API patterns

  AOB

   McCool: AOB?
   … reminding that we are meeting every week except for some
   cancellations
   … the time offset jumps back at the end of the month

   McCool: Any other business?
   … Adjourned


    Minutes manually created (not a transcript), formatted by
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     [14] https://w3c.github.io/scribe2/scribedoc.html

Received on Monday, 10 March 2025 15:03:30 UTC