WoT-IG/WG vF2F Meeting - Day 1

05 Oct 2020


Kaz_Ashimura, Michael_McCool, Hiroshi_Ota, Kunihiko_Toumura, Michael_Lagally, Takio_Yamaoka, Sebastian_Kaebisch, Jeff_Jaffe, Daniel_Peintner, Ryuichi_Matsukura, Ege_Korkan, Cristiano_Aguzzi, David_Ezell, Ken_Ogiso, Tomoaki_Mizushima
McCool, Sebastian
Kaz, Daniel, Sebastian


<kaz> scribenick: kaz


kaz, daniel and sebastian


vF2F wiki

McCool: call logistics above
... several guests for today
... IRC channels is #wot
... resources on GitHub
... schedule
... PlugFest done last week, Sep 28-Oct 2
... today Architecture/Profiles
... Oct 7: Use cases, requirements and liaisons
... Oct 13: joint meetings with DID and PUB
... Oct 14: joint meeting with APA
... Oct 15: joint meeting: with WN
... Oct 20: Discovery
... Oct 21: TD and Thing Model
... Oct 22: Scripting, Security, etc.


Lagally: holding 2-hour call every week
... version to be published as a FPWD now
... clean up a bit, e.g., for ReSpec
... topics: FPWD review - go over the draft
... then requirements
... trying to identify requirements for standardization
... terminology as well
... then two presentations
... Sebastian on Thing Model requirements, Koster on OneDM compatibility
... anything else for today?

Prev minutes


Lagally: discussion with the Pub BG Chair for the joint meeting
... FPWD publications, OneDM/Thing Model, ...
... any objections for publishing the minutes?


Lagally: approved

Architecture draft

latest draft

Lagally: no ReSpec errors now
... would like to identify owners of unassigned sections after the FPWD publication
... this is the FPWD version, and the Architecture TF is OK with publishing the draft
... (goes through the sections of the draft)
... Introduction, Conformance, Terminology, Application Domains, System Topologies
... not perfect yet
... short section on System Integration
... then Requirements
... we'll detailed discussion later
... then Abstract WoT System Architecture
... WoT Building Blocks which talks about the related WoT specs
... Thing Model, Core Profile and Discovery have been added
... then Abstract Servient Architecture
... would like to go through the newly added sections
... and see go or no-go for the FPWD publication

Kaz: (as I mentioned the other day) we need to add the diffs from the v1 version within Appendix A "Recent Changes"

Sebastian: right. it would be helpful.
... Taki is working for TD spec too

Lagally: ok
... created an issue on that

Issue 545

Lagally: had a conversation with Matthias
... he's not active anymore and to be moved to the Acknowledgement section
... some more as well
... also would like to get some more new
... created another issue on that

Issue 542

Lagally: Terminology
... definition for "Thing Model", etc.

Sebastian: I have a definition within the TD draft

McCool: would be more convenient to have the definition within the Architecture spec so that we can refer to the document for terminology

Lagally: Sebastian, please make a Pullrequest to transition the definition from TD to Architecture

Sebastian: ok

Issue 547 on terminology for Thing odel

Lagally: goes through the use cases (Application Domains/ System Topologies)
... Editor's note for "5.5 Edge Devices"
... "TODO: (McCool) Check if the current text still fits with recent edge computing activities."

McCool: nothing incorrect here
... should say "expand" instead of "check"

Lagally: ok

McCool: expand to capture the recent activities

Lagally: ok
... probably need a proof read as well
... new issue on "align languages use case vs application domains"

Issue 548

Lagally: then "7. Requirements"
... Editor's note saying "TODO: New requirements from new use cases need to be added here."

McCool: links to the requirements on the GitHub would suffice

Lagally: ok
... creates a new issue for that

Issue 549

Lagally: section 7.2 also has the same note
... then "8.1 System Components"
... "TODO: Create introductory text that introduces the concepts from the succeeding chapters."
... also "8.1.2 Thing Models"
... "TODO: Create section."

Sebastian: there is a PR

Lagally: 8.1.4 Intermediaries
... "TODO: add reference."
... then "8.4 Lifecycle"
... need references

McCool: any resources the other W3C groups?

Kaz: what about IETF ACE, etc.?

McCool: that is rather related to device lifecycle and would like to see application lifecycle

Kaz: in that case, we might want to see the multimodal lifecycle note

<jeff> [/jeff needs to drop off.]

McCool: might make sense though that's kind of old

Issue 552 on lifecycle intro text

s/application lifecyle/information lifecycle/

McCool: note that we have PRs not yet merged on LD proof, etc.
... and related discussion on how directory is managed for discovery
... think LD proof should has enough features

Lagally: what about "information lifecycle"?

McCool: need to have discussion on information in a device and metadata like TD
... put together the obvious things and then non-obvious things

Lagally: what is the difference?

McCool: examples of obvious things are cameras to take photos
... to be moved to the other devices
... sometimes you might want to include personal data
... so it's not "TODO or Not-TODO" question

Lagally: the requirements depend on the scenarios

McCool: two large categories here
... 1. data management
... 2. metadata management
... probably separate lifecyle for both
... data management should be discussed with the Privacy group

Lagally: let me capture the points within an issue

Kaz: Michael McCool should be able to work on that but people are encouraged to provide use case scenarios for this

McCool: yeah

Lagally: can assign this issue to you, McCool?

McCool: yeah
... please put labels for discovery, past FPWD and security

Lagally: done
... creates two more issues for lifecycle

Issue 554

Issue 555

<scribe> scribenick: dape

Lagally: old editors note right before 8.7

<inserted> 8.7 Protocol Bindings

Lagally: Question to Sebastian: additional oepration types coming?

Sebastian: None planned
... default operation for unsubsribe event planned
... current text is fine as is

Lagally: Building block sections
... 9.2. Thing Model is new
... 9.3. Core Profile is new
... 9.4. Discovery is new

Sebastian: working on intro text for 9.2. Thing Model

Lagally: Introduction text for 9.3. and 9.4. is planned for past FPWD

McCool: Can expand editors text for 9.4. but actual update is planned for later

Lagally+McCool: cross-referencing between Architecture and the other docs like Discovery and TD to be handled by Kaz

Lagally: Sections 10+ do not contain 1.1. changes
... need changes sections for 1.1
... 9 issues left for FPWD (Architecture)

<inserted> Issue 558

Daniel: FYI: JSONLD has a former editors list in the top of the spec

Lagally: Talked with M. Kovatsch but he perefered to move it to appendix

Zoltan: Seems to be common to have editors kept together

Lagally: no strong opinion
... suggest keep it as it is

Kaz: we can also check commit history. please note the Editors list was imported from the WoT Architecture 1.0 version, so we need to clarify who would be the active contributors.

McCool: Suggest leaving it as is
... suggest moving it out to improve citation

Kaz: Will check with Panasonic, but publishing the FPWD with the current Editors list is fine.

Lagally: Issue#546, marked as "past FPWD"
... Would like to ask Sebastian to take over
... 8 minutes break before ThingModel topic starts

<kaz> [8min break]

Thing Model

Sebastian: Would like to start with requirement document for thing model
... see https://github.com/w3c/wot-architecture/blob/master/REQUIREMENTS/thing-models.md
... many use cases for thing models
... - digital twin use case
... - mass production use case
... - simulation use case
... essentially use cases where we don't need actual TD instances
... Requirements:
... - defining common elements
... - minimum requirements

<Mizushima> --> https://github.com/w3c/wot-architecture/blob/master/REQUIREMENTS/thing-models.md thing model

Sebastian: - possible to define partial (or template based) security definitions

<inserted> 10. Thing Model from the TD draft

Sebastian: At the moment section "10. Thing Model" is in TD
... content comes from Annex C
... previous name was "Thing Description Template"
... still discussing content type requirement
... We are trying for formalize the chapter right now
... also work on text about differences between "TD" and "Thing Model"
... object oriented programming paradigm: class vs instance
... Thing Model defines model for a thing: common metadata, no/partial security, no protocol or template

Lagally: Figures contains term "template". Is thera definition?

Sebastian: Not yet

McCool: coming from URI template

Lagally: Need to explain how missing data is completed

McCool: 2 options
... 1. omit
... 2. named values
... problems like name collisions may arise

Sebastian: Chapter 10 is still under construction
... The TD follows the ThingModel and includes missing data/portions
... instance specific data

McCool: for security it is good to know the type of security
... but the authorization server does not need to be known in advance

Sebastian: Links make more sense in instances

McCool: depends on link relation types
... some kind of links may be in Thing Model

Lagally: Good point
... brings multiple inheritance back
... how can a TD be implementing 2 Thing Models
... eg. switch and a lamp

Sebastian: extension feature will be addressed
... technical solution is not decided yet
... re-use what we have?
... JSON schema, JSON-LD, ...
... need technical evaluation

McCool: Closeley related to modularity
... maybe avoiding certain conflicts
... aligning with oneDM structure

Ege: w.r.t. multiple inheritance: prefer using "one" ThingModel but add support merging 2 thing models into one

Lagally: Makes sense

Sebastian: Agree also
... should clarify the approach

Cristiano: there is not only inheritance but also composition
... need to clarify when to use what

Lagally: Agree, we will see both types

<McCool> McCool: agree with idea of doing composition of thing models (ideally still with modules) and then single inheritance ("implements" relation from TD to TM)

Lagally: how do we put things together

Sebastian: Please have a look at new section 10 in TD document
... there are new assertions
... introduces also @type "ThingModel"
... there is also a new "placeholder identifier"

Lagally: Issue how to escape double brackets

Sebastian: We have an issue with that regard

<McCool> McCool: think we should follow existing systems in that regard (example is "mustache")

Sebastian: Note: TD document contains Thing Model definition already

<inserted> PR 540

Sebastian: I prepared PR#540 for architecture
... added 2 paras explaining Thing Model

Lagally: Any comments/questions?
... propose merging
... no objections --> approved
... need to resolve conflict first
... PR#539
... comes from Zoltan

Zoltan: Made more changes
... scope is device lifecycle
... please let me know if there is something more or missing

Lagally: Suggest to take what we have and improve later (if necessary)
... suggest resolving merge conflicts and merging
... Need "owners" for FPWD issues

Sebastian: BTW, resloved merge conflict

Lagally: Okay, then let's merge PR 540

<inserted> PR 540

Lagally: back to "owners" for issues
... I will take some

McCool: can take issue#549

<kaz> Issue 549

Zoltan: Note: huge merge conflicts but can solve them

Lagally: Time check? Agenda check
... carry over to architecture call on Wednesday

<kaz> Updated agenda for today

Lagally: 5 minutes break

<kaz> [5min break]

<kaz> scribenick: sebastian

WoT Profile

Lagally: Specification is in early stage
... it has many editors note
... many details are missing

<Mizushima> --> https://w3c.github.io/wot-profile/ wot-profile draft

Lagally: however, good base for discussion
... we need active contributions, implementations, etc.
... which features should be adopted, which are common ground, etc.
... we need some feedback, how the current assumptions work

McCool: there are different use cases such as out of the box interoperability. are there more missing?

Lagally: first concentrate on OTB interop.

<Ege> https://github.com/w3c/wot-profile/issues/37

McCool: we need also discussion about extensions like geo location in the TD
... however, we should limit the extensions

Ege: I provided a review as an issue
... there are two concerns

<kaz> 5.1.22 Recommended practice

Ege: one is about events
... web sockets are very open
... other comments about small feadbacks

Lagally: many details, we should go over in detail

issue https://github.com/w3c/wot-profile/issues/37

Ege: What makes the enum special?

Lagally: is type safety and based on simple types

Chris: A concrete example could help with the enums

Ege: "format" is not supported anymore in JSON Schema

Seb: use a different term?

Ege: No, its a different mechanism
... Type is a must, but what is about photos?
... there needs better explaination when JSON is used as content type

Lagally: However, we just describe Thing Model Data Types there
... Should there be an assertion saying terms not in TD are not allowed for DataSchema, i.e. anyOf

Ege will provide a specific issue

Ege: misstake about the input of actions. It allows objects

Lagally: We running out of time. Cont. in the next call

Ege: Regarding security, shall all scopes be supported?

McCool: We should follow the security guidelines.

Lagally creates an issue about the different OAuth2 options

Lagally: continue on Wed. about the inputs from Ege

Ege: Current draft of WoT Profile is not ready for FPWD, especially the Event part

Lagally: Will be more feedback expected?

Daniel: I will read the current status

Cristiano: I will also review

McCool wraps up

Kaz: How should be the title name of the Arch 1.1?
... something like "wot-architecture11"?

Sebastian: dot or without?

McCool: I think "wot-architecture-1-1" is better
... what did the JSON-LD spec do?
... is there a convention?

<kaz> JSON-LD uses https://www.w3.org/TR/json-ld11/ for their 1.1 version
... and different groups use various notations
... TTWG uses https://www.w3.org/TR/ttml-imsc1.1/ for IMSC 1.1
... ARIA WG useshttps://www.w3.org/TR/accname-1.1/ for "Accessible Name and Description Computation 1.1"

[Day 1 adjourned]

Summary of Action Items

Summary of Resolutions

[End of minutes]

Minutes manually created (not a transcript), formatted by David Booth's scribe.perl version (CVS log)
$Date: 2020/10/07 11:07:27 $