W3C

- DRAFT -

WoT-Architecture

13 Feb 2020

Attendees

Present
Call 1: Kaz_Ashimura, Michael_Lagally, Kunihiko_Toumura, Zoltan_Kis
Call 2: Kaz_Ashimura, Michael_Lagally, David_Ezell, Michael_Koster

Regrets
Chair
Lagally
Scribe
kaz

Contents


Call 1

<scribe> scribenick: kaz

Previous minutes

Feb-6 minutes

Lagally: (goes through the minutes)
... Zoltan, have uploaded your slides yet?

Zoltan: yes, created a Pullrequest

Lagally: (continues to look into the minutes)

Kaz: URL for Zoltan's slides?

Lagally: let's merge the PR to fix the URL

PR 434

Lagally: merged
... and the minutes are approved

Zoltan's slides

<scribe> ACTION: kaz to add the URL for Zoltan's slides to the minutes

Issues

Issue 435

Lagally: Fleet management use cases

Issue 436

Lagally: requirements for home network scenarios
... based on the old use case descriptions by the Web&TV IG's Home Network TF

Home network use cases

Lagally: we should discuss the detail when Chris Needham is available
... need to use more time for the discussion expected next week

Issue 433

Lagally: Michael McCool will describe this maybe the second call

Issue 432

Lagally: I'm working on this

other issues

Lagally: we still have other issues and need volunteers
... e.g., data streaming (issue 387)
... possibly could get comments/ideas from NHK and the MEIG guys

https://github.com/w3c/wot-architecture/issues/25

Lagally: WoT in the Web browser
... how to involve browser vendors?

Zoltan: many discussions about that so far
... possible JavaScript library which uses Fetch, etc.

Lagally: (adds comments to Issue 25)

Zoltan: got discussion with browser vendors but it seems generic API-based approach would not be promising for WoT
... there is no browser vendors who want to implement our ideas like extensions based on the fetch API or the WebAssembly solution
... so at the moment, we might want to generate polyfill implementations

Toumura: browser is a consumer of devices?

Zoltan: primarily a consumer but could be a producer

Toumura: ok

Lagally: so nobody is implementing WoT natively within the browsers
... but do we have any concrete use cases for browser integration?

Zoltan: browsers included in sensor fusion
... myself don't have a use case which include a Web browser as a producer

Lagally: no concrete use case for exposing things yet
... can consider sensor fusion/mashup at the moment
... this use case is already covered, however, WebAssembly/WebWorkers would be a different way to implement

Kaz: when we say "web browsers", we should think about use cases for both their hardware side (when empbedded within a device) and the software side (when installed on a PC/smartphone)
... and then think about what kind of features to be used for which use cases
... like digital TV set as a device and speech interface on a smartphone

<zkis> Example for using node-wot from browser: https://github.com/eclipse/thingweb.node-wot#as-a-browser-library

Zoltan: the above is the link for using node-wot on a browser

PRs

PR 428

Lagally: Digital twin use cases
... seems it's mixed up and need some cleaning
... let's concentrate on the digital-twin-use-case.md for now

digital-twin-use-case.md

Lagally: (goes through the "Motivation" section)
... terminology for "digital twin"
... also called as "twin" or "shadow"
... (goes through the "Expected Devices" section)
... (Expected Data)
... (Dependencies)
... WoT Architecture, TD, Profile, and possibly Scripting?
... need to have a way to extract the data model
... though digital twin itself uses abstract-level data
... (Description)
... better visibility, accurate prediction, what-if analysis, documentation and communication, integration of disparate systems
... (Variants)
... * virtual twin
... ** intermittent connectivity, protocol abstraction, business rules
... ** and examples
... * predictive twin
... * twin projections
... that was quick run-through of the digital twin use case
... regarding the "Gaps"
... we have ranges for values and units already
... but we don't currently have a way to describe simulated behavior
... also templating mechanism
... and data model separation from the binding
... we still have 10 more minutes, so let's see another use case

PR 431

Lagally: there is only one use case description here

X-Protocol Interworking.md

Lagally: Cross protocol interworking
... (Motivation)
... bridge more than one protocol
... for interoperability accross protocols
... possible limitation based on the capability of each protocol
... if we want to think about interoperability, we need to consider that point
... (Description)
... a couple of examples here
... smart home environment
... industrial environment
... smart city environment

Zoltan: wondering who would really use multiple protocols at once
... we have a specific/concrete use case already
... and do we want to have this kind of generic use case as well?

Lagally: would think about a device which exposes its capability in multiple ways

Zoltan: we could use native bridges between WoT and native connection
... if this approach is successful, it would be great
... but a good homework

Lagally: I see a big value
... we could have wide variety of devices
... and a lot of implementation complexity

Kaz: think we should clarify the concrete descriptions about each example use case a bit more
... and then we could think about (1) a category of use cases which includes "cross-protocol interworking" or (2) requirements for "cross-protocol interworking" based on the use cases later

Lagally: ok
... (adds comments to PR 431 about that point)

Lagally's comments

Toumura: in that case, probably we should think about some concrete use case like smart home for Discovery purposes as well?

Lagally: right

[Call1 adjourned]


Call 2

<scribe> scribenick: kaz

Previous minutes

Feb-6 minutes

Lagally: (goes through the minutes)
... discussion on the state diagram
... onboarding/discovery and additional things
... and device lifecycle
... Zoltan did great job for the survey
... end-to-end security by McCool
... Zoltan's slides now available
... PRs for use cases
... can approve the minutes?

Koster+David: fine

Lagally: minutes approved

Zoltan's slides

Issues

Issue 436

Lagally: use cases/Requirements from the Web&TV IG's Home Network TF
... which of those could be still relevant?

Requirements for Home Networking Scenarios

Lagally: 9 years old
... Opera, CableLabs, Ericsson, Telecom ParisTech, BBC, Samsung and Sony were involved

Koster: might be able to contact the Editors

Lagally: next week, Chris Needham, one of the MEIG Chairs, is expected to join the Architecture call
... let's revisit this issue then
... if you have time, please look into the document

Issue 25

Lagally: WoT in the Web browser
... 2.5 years back
... had discussion with Zoltan during the first call today
... it seems browser-native implementation is currently out of scope
... there is a possibility of using a Web browser as a Thing exposer

David: should keep this issue open
... someone should talk with TAG and browser vendors

Lagally: what specific question should we ask them?

David: would see McCool's advocacy on edge computing based on service worker
... wish his comments

Kaz: we already have several pieces but I think we should think about both the device side and the software stack side of the Web browser (as I mentioned during the first call today)

Lagally: (adds comments to Issue 25)
... this may be related to service workers. we should think about separating physical device (hardware) and Web browser (software stack)

Koster: maybe embedded browsers use web socket protocol to interact with outside servients
... that is a possible use case
... e.g., TV could be a smart Things hub

Lagally: would be good to generate a concrete use case description

Koster: will do that

Lagally: (assigns Issue 25 to Koster)
... the other issues on discovery (425), digital twin (426), edge device (427), etc.
... but let's see PRs

PRs

Digital Twin use case

Lagally: (goes through the use case description)
... (Motivation)
... representative of a real Thing
... you can use it to collect data including time series of data
... scaling up to multiple devices
... can monitor everything
... can be called as "twin" or "shadow"

Koster: we have an end-point app
... would be a same thing

Lagally: cloud API as interface to the virtual thing?

Koster: yes
... API for cloud input

Lagally: ok
... there are several connection patterns
... can use the model for prediction
... and create a simulator
... can create a what-if analysis system
... also a combination of simulators
... also integration of simulators and physical devices
... (Virtual Twin)
... intermittent connectivity
... (Predictive Twin)
... you can use machine learning for precise prediction
... (Twin Projections)
... questions?

(none)

Lagally: can quickly talk about the "Gaps"
... managing multiple devices using the template mechanism
... various instances could be involved but we don't have a template mechanism for that situation
... (adds comments mentioning we reviewed this PR)
... (and merges PR 428)

PR 431

Lagally: we need some more stakeholders like McCool for this discussion
... so would defer this to next week

AOB

David: DID WG meeting in Schiphol
... suggested they coordinate with WoT

<dezell> https://www.w3.org/2019/did-wg/Meetings/Minutes/2020-01-29-did#section4

David: includes the link to the slides
... retail industry should be open
... that is very important
... many of the WoT use cases are applicable to retail industry
... encouraged Conexxus guys to generate TDs
... will also go to the Helsinki f2f

Lagally: tx for the quick wrap-up
... should we create a specific retail use case?
... would work together to generate one

David: (mentions some possible use case)
... this kind of control and safety

Lagally: ok
... pretty concrete use case
... let's write it down based on the use case template

David: happy to help

<scribe> ACTION: Lagally and David to work on a use case for retail services

Kaz: completely agree with you both that we should work with the DID WG, and should create concrete use cases starting with retail services

Lagally: aob for today?

(none)

[Call 2 adjourned]

Summary of Action Items

[NEW] ACTION: kaz to add the URL for Zoltan's slides to the minutes
[NEW] ACTION: Lagally and David to work on a use case for retail services
 

Summary of Resolutions

[End of minutes]

Minutes manually created (not a transcript), formatted by David Booth's scribe.perl version 1.154 (CVS log)
$Date: 2020/02/17 08:58:42 $