W3C

– DRAFT –
WoT Profile

31 July 2024

Attendees

Present
Ben_Francis, Daniel_Peintner, Ege_Korkan, Kaz_Ashimura, Luca_Barbato, Michael_Koster, Sebastian_Kaebisch, Tomoaki_Mizushima
Regrets
-
Chair
Luca
Scribe
dape

Meeting minutes

Minutes review

<kaz> July-17

Luca: Talked about patch w.r.t. out-of box interop
… showed notes of previous meetings
… Ben explained what should be a profile and what not
… Koster seemed to have different ideas
… would like to take this topic up again

Luca: Any objections?
… none -> Minutes approved

Profiles as Ecosystem descriptors

Ege: Luca, can you explain overall concept

Luca: Let me try to summarize
… least amount of profiles... greenfield (Ben's position)
… other opinion, any people greenfield is others people brownfield (Koster's position)

Luca: Are we able to use our framework (or way of thinking) for greenfield or other ecosystems also

Koster: greenfield vs brownfield is adequate framing
… in bindings we have different protocols like HTTP and CoAP
… but we have also matter with a different protocol (e.g. Matter)
… I think profile might need its own protocol
… profiles for ecosystems also?
… not sure about difference between profile and binding

Koster: protocol binding should be focused on protocol ... rest in profile

Ege: in eco systems there is also data modelling
… no out-of the box interop if we can't decide on temperature format etc

Koster: I was thinking there other problems also
… useful to have industrial IOT data-model
… like temperature standardization

Luca: We will have TD2 to describe what is used in profile
… currently not the case for TD1.1
… profile collections of bindings
… at the same time you will have constraints
… a profile is going to tell what a thing can support/implement
… like a toolbox we can pick of

Luca: we don't have consensus on numbers and overlap of toolboxes

DP: Totally agree, we should subsetting TD2.0

Ben: Profile should constraint not extend
… distinction greenfield vs brownfield
… profile vs bindings ...
… prescriptive vs. descriptive

Ben: we should have as many bindings as possible but as few profiles as possible
… e.g. don't see benefit of having Matter profile
… Matter provides already guarantees

Ben: I don''t think we should many profiles

Kaz: I agree with Koster and Ben
… anyhow, have difficulties to understand current position of profile
… expectations for profile?
… would see what is expected for Profile and what is expected for Binding based on some concrete use case including several Things and Consumers from several different Ecosystems.

Luca: The conflicting point is not clear
… just using bindings is not satisfactory
… profiles towards pre-existing ecosystems
… so we can get more people on board
… concern: too many profiles cause fragmentation
… new adopters might get confused
… small set of profiles is useful for them
… we need a way to onboard other organizations

Ege: distinction to be made...
… small number of profiles
… vs. bindings like Matter, OPC UA etc
… they are out and should be usable
… in building automation no one will pick HTTP
… most likely BACnet will be used
… but they don't have thing description format
… we want to have guidance .. which leads to data model ... like temperature
… guidance to beginners is a valid point
… anyhow, spec is already too long

Ben: I do understand the problem of integrating new platforms
… but I think profiles are the wrong tool for it
… we should focus on use-cases and requirements
… for profiles in the future
… were I created a PR

Luca: Besides the term we can use -- platform binding.. collection of other bindings .. for me is a profile
… we can differentiate between profiles for beginners and for other systems ... technically it is the same
… new comers vs up-graders

Ben: platform binding vs. profile
… my proposal to solve overlap: move protocols binding into set of defaults to bindings
… profile becoming sub protocol ... for a given IoT platform

Koster: I am not proposing to make the sub protocols
… could be one of the constraint vector
… component of testing/certification
… not in scope of WoT

Koster: We should offer convenience people are used in other platforms like BACnet
… offering device standard
… or enabling consumers
… interop across ecosystems

Ege: w.r.t. platform bindings
… e.g. HTTP, JSON
… further like JSON has to look like this....
… this is the other aspect

Luca: My proposal. TD2.0 should remove sub-protocol
… sub protocol is result of process

Luca: we have to interop/bride between eco systems
… with semantics we can match Modbus values on the wire
… temperature Fahrenheit converting to Celsius
… should be expressive enough
… consumer should not have to implement everything
… would be way to complex

Ben: Profiles becoming device standard
… very unlikely
… more likely profiles used by bridging
… cloud service monitor buildings
… one profile using HTTP better than a hundred
… IoT is different .. but there is value in bridging
… btw, sub protocol keyword needed for web-socket

Luca: subprotol should be removed
… should become first class citizen.. it is a "protocol"

Ege: Ben's use case with gateways
… nice written TDs should be sufficient

Luca: We have to decide whether we want to continue discussion in 2 weeks
… a layer of warranting interop
… thing models in a more extensive way could be used
… maybe too constraining
… will try to put down were we have consensus

[adjourned]

Minutes manually created (not a transcript), formatted by scribe.perl version 228 (Tue Jul 23 12:57:54 2024 UTC).