- From: Kazuyuki Ashimura <ashimura@w3.org>
- Date: Tue, 09 Sep 2025 00:50:46 +0900
- To: public-smart-cities@w3.org
- Cc: group-wot-ngsi-ld@w3.org
available at:
https://www.w3.org/2025/09/08-smart-cities-minutes.html
also as text below.
As mentioned during the call, I'll organize another Doodle poll to
identify a good slot for the next call in October.
Note that we agreed to have a hybrid F2F meeting during TPAC 2025 as
a TPAC breakout session. So I'll organize a Doodle poll to see which
day from TPAC would fit people also.
Thanks,
Kazuyuki
---
[1]W3C
[1] https://www.w3.org/
– DRAFT –
Web-based Digital Twins for Smart Cities IG
08 September 2025
[2]Agenda. [3]IRC log.
[2] https://github.com/w3c/smart-cities/blob/main/README.md#8-sep-2025
[3] https://www.w3.org/2025/09/08-smart-cities-irc
Attendees
Present
Juanjo_Hierro, Kaz_Ashimura, Martin_Bauer,
Michael_Koster, Tomoaki_Mizushima, Torbjorn_Lahrin
Regrets
-
Chair
Koster
Scribe
kaz
Contents
1. [4]Logistics
1. [5]Guests and IEs
2. [6]Quick Intro
3. [7]Minutes
4. [8]F2F Meeting at TPAC 2025
5. [9]NGSI-LD Collaboration
1. [10]About FIWARE
2. [11]Digital Twins as basis for the architecture...
3. [12]Digital Twins: an approach for integration at
multiple levels...
4. [13]What are we referring to as Digital Twins
5. [14]Data Exchange API: ETSI NGSI-LD
6. [15]FIWARE driving key standards: Smart Data Models
7. [16]Smart Vertical solution: Reference Architecture
(Smart Cities)
8. [17]Example: Initial Smart City Reference Architecture
9. [18]WoT:Things and GSI-LD:Entities
10. [19]Compatibility of NGSI-LD with Thing
Models/Descriptions
11. [20]Summary
6. [21]Next meeting
Meeting minutes
Logistics
Guests and IEs
Kaz: Torbjorn is now an official IE
… also we have two guests from ETSI/FIWARE
Koster: yes
… discussion about NGSI-LD
… also Torbjorn from the Nordic Smart Cities activity
… welcome!
Quick Intro
(starting with Juanjo)
Juanjo: FIWARE tech committee Chair
Martin: principle standardization
… vice Chair of FIWARE committee
… NGSI-LD from the beginning
Torbjorn: nice to have you both
… in Sweden, we have Nordic Smart City project
… using the platform based on FIWARE stuff
… so welcome to see the technology
… also smart city community within W3C
… also engaged with European dataspace work
… also Chair of strategic coordination for Metaverse
Koster: a lot of activities around those topics
… move things forward in more coordinated way would be nice
Minutes
[22]July-7
[22] https://www.w3.org/2025/07/07-smart-cities-minutes.html
Koster: (goes through the previous minutes)
… we're working on the technology landscape
… adding more categories for the technology
… also vocabulary is very important
… pretty broad activities
Torbjorn: Mark and I had discussion about ontologies for smart
cities
… Mark has been working on that, that's good
… the problem is there are many of them
… people have their own ontologies
… if we can have some ontology for everybody, that would be
great
… we have 3-4 vendors in Sweden but all of them have their own
ones
… make one changes their own ontology
… so there is a challenge about alignment and interoperability
… sharing data within, e.g., European Dataspace
… convergence is needed
… happy to have discussion about the problem
… would elaborate the challenges
Juanjo: one of the advantages why FIWARE has become popular
… across various cities
… guess you're familiar with the models
… smart data models, etc.
… associated to that
… what we have is really implemented approach
… decided based on communities' requirements
… company organization implementing and contributing to real
projects
… analysis and potential collisions
… we have so far big number of cities working on that
… and widely adopted
… implementing FIWARE's datamodel
… in many cities before FIWARE is around
… there was a gap on how to integrate things
… we handle that based on the idea of digital twins
… fancy tools of 3D visualization itself is not important but
the data model is important
… structured layer to be used
… context broker implements the mechanism
… this arouse to overcome the issues with old systems
… adaptation of the mechanism will accomplish the
interoperability
… between one data and another
… what is important is the data
… what data to be provided by the system
… e.g., for a traffic management system
… also what kind of data to be used to improve the system
… all the data to be harmonized with each other
… ID management in addition to NGSI-LD
… would like to talk about the background around FIWARE today
Kaz: great
… actually, your presentation is the main topic for today
… please let Koster wrap-up the minutes review quickly
Koster: ok
… (wrap-up the minutes review)
… (quickly goes through the rest of the minutes from July-7
meeting)
… Mark Fox gave nice description about his ontology work
… any comments/questions?
(none)
(minutes approved)
F2F Meeting at TPAC 2025
Koster: TPAC is the main tech meeting of W3C
… we'd hold a F2F meeting as breakout during TPAC
Torbjorn: when to have that?
Kaz: probably on Wednesday, Nov 12
Torbjorn: hybrid?
Kaz: yes
… and we can decide on the date later :)
Koster: sounds good
NGSI-LD Collaboration
@@@ slides tbd
Kaz: do you think you can share your slides publicly?
Juanjo: yes, after some changes
Kaz: great
About FIWARE
Juanjo: (gives background about FIWARE)
… IoT-enables smart solutions
… also smart organizations
… working on dataspaces for 12 years or so
… invocation of services
… FIWARE community intends to contribute to creation/evolution
Digital Twins as basis for the architecture...
Juanjo: digital twin representation for the real world
… constantly keep up to date
Digital Twins: an approach for integration at multiple levels...
Juanjo: architecting, integration, ...
What are we referring to as Digital Twins
Juanjo: digital "replica of an asset
… characterized by attributes
… values of attributes may change over time
… typically have a location
… APIs about how to implement actions
… also handling common data models
… NGSIv2 => ETSI GSI-LD API
Data Exchange API: ETSI NGSI-LD
Juanjo: (Context Broker connected with bus, citizen, shop, ...)
… not only for citizens but various industry domains
… some of the targets are related to multiple domains
… NGSI-LD is a simple powerful REST API
… simple: what you want in a RESTful API
… entity types, entities, attributes
… GET, POST, PUT, PATCH, DELETE operations
… powerful: supported operations
… geo-queries, subscription/notification, pull/push, multiple
data rendering, ...
FIWARE driving key standards: Smart Data Models
[23]Smart Data Models
[23] https://github.com/smart-data-models
Juanjo: collaborating with relevant orgs
… how the map into JSON-LD also
… data modes based on well-established standards, e.g.,
schema.org, SAREF, IEC CIM in Energy
Smart Vertical solution: Reference Architecture (Smart Cities)
Juanjo: multi-tier architecture
… 4 major layers, data acquisition layer,
processing/analysis/visualization
… AI/ML algorithm to be also applied
Example: Initial Smart City Reference Architecture
(diagram)
Juanjo: (describes the diagram)
… there might be a system which doesn't require FIWARE standard
… but the architecture including the Context Broker can work
that as well
… bring all the data to the common data layer
… the data can be consumed by the other vertical solutions
… these days considering VC/DID as well for identification
management
… ability to create market places also
… establish the contract for various services
WoT:Things and GSI-LD:Entities
Juanjo: a WoT Thing may map well to an NGSI-LD Entity
… (shows an example Thing Description about that idea)
Compatibility of NGSI-LD with Thing Models/Descriptions
Juanjo: WoT may specify what would be the default Thing
Description derived from a Thing Model
… then how to implement Actions for NGSI-LD should be clarified
… (shows some more discussion points)
Summary
Juanjo: WoT and NGSI-LD look compatible
… opportunity to specify how they can work together
… but we need further clarification to see the details
… we did some work about that including DTDL, etc.
… we need standard way for digital twin representation as well
… how to harmonize that layer is also a question
… so collaboration with W3C has been established
… 1:1 conversion with WoT Thing Description to be discussed
… Property is comparably straightforward
… that's the basic background of the collaboration
Koster: that's really exciting!
… sort of start-off for further discussion
… JSON Schema as basic definition language, for example
[24]Smart Cities IG Charter
[24] https://www.w3.org/2024/06/smart-cities/
Kaz: completely inline with the Charter
Torbjorn: also interested
… a bit curious about how to support the declaration for
Citiverse, etc.
… what possibility do you see?
Juanjo: depends on what we find
… we already have experience on integrating different
technologies with NGSI-LD
… integrating more out-of-desk things
… it's still something to be developed
… so far our impression is very promising
Torbjorn: ok
… another question about the main branch for integration
… we're referring to NGSI-LD also
… on top of NGSI-LD
Juanjo: this was something several years ago
… reference implementation of each component
… we're going for more inclusive approach
… there are several different context brokers
… there is no enforcement to force people make commitment to
our repository, for example
Torbjorn: bringing what we did back to the NGSI-LD repo?
Juanjo: there is the FIWARE catalog but you don't have to take
all of them
Torbjorn: there is a sensitive branch when people make
contributions
… there are several vendors from Sweden, though
… would be helpful if we could clarify how to organize FIWARE
stuff and W3C stuff
Kaz: that's really a good point
… and should be included into the topics for this IG
… for example, W3C Registry mechanism could be helpful for that
purpose
Koster: exactly, this is really good point
… any other business for today?
Next meeting
Juanjo: when to have the next meeting?
Kaz: usually hold on the 4th Monday
… but will create a Doodle poll to fine a good slot for people
Koster: ok
… meeting adjourned
[adjourned]
Minutes manually created (not a transcript), formatted by
[25]scribe.perl version 244 (Thu Feb 27 01:23:09 2025 UTC).
[25] https://w3c.github.io/scribe2/scribedoc.html
Received on Monday, 8 September 2025 15:50:51 UTC