W3C

– DRAFT –
WoT-WG/IG

12 February 2025

Attendees

Present
Charith_Perera, Daniel_Peintner, David_Ezell, Ege_Korkan, Josh_Thomas, Kaz_Ashimura, Kunihiko_Toumura, Michael_Koster, Michael_McCool, Sebastian_Kaebisch, Tetsushi_Matsuda, Tomoaki_Mizushima
Regrets
-
Chair
Koster
Scribe
McCool, kaz

Meeting minutes

Agenda

<kaz> Agenda for today

Koster: any additions or changes to the agenda?

Koster: agenda approved

Guests

Koster: none

Minutes

Feb-5

Koster: review offline expected; main points, inclusiveness asked for people to also comment on issue; updated holiday (Golden Week); policies (merged IE policy); usecase backlog and resolution to allow UC TF to draft proposed UC/US

Koster: any corrections?

Koster: no corrections, minutes approved.

Quick Items

Ege: For inclusiveness, is a TF resolution; have labelled all issues

<EgeKorkan> https://github.com/w3c/wot-binding-templates/issues?q=is%3Aissue%20state%3Aopen%20label%3A%22registry%20mechanism%22

McCool: link to resolution?

<EgeKorkan> TD-TF Resolution on Binding Registry

Ege: here is the text of the resolution: RESOLUTION: The binding document linked in the registry entry DOES NOT have to be open to read, use, implement. However, the binding MUST be reviewable by the reviewers.

Koster: still have to make sure there is no other legal review needed, but I think this policy leads to a simple separation of responsibilty. There should be an open summary document, however; we can have a form to collect the necessary information, and this information would be published in a W3C document so would have to have W3C copyright.

Koster: so for instance, it would be good to have information on the various restrictions in the summary document.

Kaz: ok with basic policy; maybe should have a resolution by the entire group. And then we should think about how to proceed (=the concrete procedure) next.

proposal: The binding document linked in the registry entry DOES NOT have to be open to read, use, or implement. However, the binding MUST be reviewable by the reviewers.

RESOLUTION: The binding document linked in the registry entry DOES NOT have to be open to read, use, or implement. However, the binding MUST be reviewable by the reviewers.

Notices

Koster: none

Meetups

WoT CG

Koster: WoT CG meetup on Feb 20 - JSON Schema and AI
… another one on March 10 on mixed reality

WoT JP CG

Mizushima: no new plans for WoT JP CG

Smart Cities IG

Koster: Smart Cities IG, split meeting for two timezones

Kaz: US Pacific Doodle is ongoing - please respond

<kaz> Pacific-friendly poll

Kaz: so far Monday 10pm JST and Tuesday 10am or 11am JST are main candidates, but there are some more candidates for the Pacific-friendly one. So if you're interested but you've not responded yet, please respond.

Cloud-Edge-Client CG

McCool: for CEC, no meetings planned, but looking at additional members, scope, some proposals (e.g. Distributed Workers)

Liaisons

OPC Foundation

Sebastian: OPC UA, talked about binding ontology
… many definitions we don't really need
… started discussion on mappings, OPC UA has node-set file
… strategy in standard how mapping looks like
… if you have a node-set, would like to be able to convert it to a TD

McCool: when do expect things to be wrapped up?

Sebastian: definitely before the end of the year
… no big blocking points, very optimistic; should have an early draft in a few weeks

Koster: a lot of the big issues were resolved early on
… nodeset can be anything - may not have an interface?
… is that correct, e.g. can it be a room?

Sebastian: not an expert, will get a data model tree, may be references to other servers; but also a lot of things in nodeset that are not needed in TD
… idea is to take a node-set as a source to generate a TD, not to map ALL the information in the node-set

Sebastian: will just reflect data model in node-set file, won't necessarily copy all metadata

McCool: issue really is do we have OPC UA nodeset that correspond to affordance-less TDs that just represent real-world entities, e.g. rooms?

Sebastian: is a feature to refer to external references... actually use JSON Schema

Koster: patterns is $ref - similar to SDF

Kaz: is nodeset here a group of Things? What do you mean by node-set?

Sebastian: just an OPC UA concept, but is like a TD; only used in OPC UA.

Sebastian: is however serialized in XML that describes the full data hierarchy in OPC UA server
… is a very hierarchical structure, have links etc. to parent node, etc.
… don't need that information in TD...

Kaz: if that is the case, then a node-set can have sub-node-sets?
… e.g. room could have AC node inside it, etc?

Sebastian: yes, that is the case; call them objects, not devices
… for each object we will have a TD

Kaz: ok, so we also need to think about gaps, collections

McCool: suggest that we keep it simple at first, maybe look for more complex test cases in OPC UA that use collections

Kaz: Yeah, agree. However, we still need to identify the gaps and how to bind TD with their specs for necessary use cases.

Koster: need to think more about formalism around linking, etc.

Sebastian: OPC UA people very interested in this and WoT

NGSI-LD

McCool: no meeting this week
… but I've read their specs
… their basic concept is property graphs
… WoT TD stores correction of Things
… conceptually related to OPC UA as well
… using NGSI-LD broker, which is essentially a directory
… quite interesting
… need to explore a few things
… blank node approach for property graphs
… how to model specific cases is the question
… e.g., smart cities
… we don't currently have many participants in the joint meeting on Monday
… but there is useful stuff there
… another point is NGSI-LD already handles geolocation information
… WoT Directory 2.0 can use NGSI-LD possibly
… please join the joint meeting on Monday
… we'll have the meeting next Monday

Kaz: thanks, based on results let's continue discussion with them

Koster: what is trajectory of TDs to describe things that do not have affordances...

McCool: my thought here is we should not reinvent RDF using Things
… for modelling relationships etc. we can just use linked data, and can use TDs only for "Things" that DO have affordances

Koster: ok, let's talk about that

Schedule

<kaz> Holidays

McCool: so we DID decide to cancel meetings during Golden Week; in wiki

McCool: as for publications, deadlines are coming up, will have to start thinking seriously about the process, queuing things up, etc.

Daniel: regarding Scripting API, think we can remove that from the agenda, the time is working well

Kaz: several holidays in US, Japan; late Feb, only Feb 26 cancelled, right?
… suggest cancel meetings on Feb 24: chairs, NGSI-LD

McCool: no problem, no main call that week, we just have to let NGSI-LD know

Policies

Koster: no updates, still working on moderator policy
… IE policy draft - we agreed to merge

Koster: ok, I will do that

<kaz> IE policy discussion on Feb 5

AOB

Koster: any quick TF reports?

Daniel: Scripting, main goal is to allow for extending API to query and cancel actions
… underspecified in the TD
… waiting for TD to have a good solution

<kaz> Feb-5 Scripting minutes

Koster: adjourn

Summary of resolutions

  1. The binding document linked in the registry entry DOES NOT have to be open to read, use, or implement. However, the binding MUST be reviewable by the reviewers.
Minutes manually created (not a transcript), formatted by scribe.perl version 242 (Fri Dec 20 18:32:17 2024 UTC).