Web of Things IG TF-AP meeting

22 Jul 2015


See also: IRC log


Johannes, Joerg, Kazuaki, Francois, Daniel, Soumya, Takuki, Vlad, Kaz, William_Miller


Johannes: 3 topics on the agenda. Report on joint meeting with IRTF. Invitated talk from Sensei group. Then talk about Bluetooth profile.

Report from the joint F2F with IRTF T2T pRG

[Johannes projects the report]

Johannes: meeting at IETF93 in Prague. Joerg presented the work of the WoT IG. Heard about work done in IRTF.
... Discussions on network management for radios and other topics.
... as well as on the architecture we've been discussing so far.
... Then breakout session where I gave a report on our progress in that Task Force so far.

-> https://github.com/t2trg/2015-ietf93/blob/master/slides/21-joint-meeting-TF-AP-report.pdf Slides

Johannes: I presented the patterns. After the F2F, when we agree on these patterns, I'll convert them to UML and put on the Wiki.
... Focus area on providing APIs and protocol mappings that make up the thing model.
... Brief introduction of our use case document. Introduced building blocks that work across domains.
... Then technology pick and metric for selection together with non-functional requirements.
... The Web Thing Model is a discussion we've been having for some time now.
... The current agreement is that we have events that allow a user to listen to changes.
... Then actions to operate the thing and properties.
... Then I presented the problem statement to observe things from CoAP, as well as HTTP.
... Solution must include the possibility to subscribe to things, where we can put things such as frequency thresholds.
... There was agreement on the approach.
... The outcomes of these discussions are:
... 1. Formal description draft for the RESTful approach
... 2. Focus on a specific scenarion to have some kind of black test in a future meeting to see what we need to interact with these things.
... 3. A cookbook or best practices document on implementing RESTful APIs
... The minutes are public on GitHub.

-> https://github.com/t2trg/2015-ietf93 IETF93 slides and minutes

Johannes: I think the cookbook document is really good input for us. It gives a good impression as to the intents of this RESTful modelling.
... Questions?

Bluetooth GATT profile

Kazuaki: In the architecture model, section about Bluetooth and legacy devices. The assumption described the GATT API, so presenting what GATT is.
... There is a Bluetooth Core spec 4.2 (more than a thousand pages) which defines GATT.
... GATT defines two roles for the server and client. GATT accomodates services and associate behavior and functions with the devices.
... Two types of services: primary and secondary, depending on the functionality.
... The primary functionality should be contained in a primary service with only one instance exposed to the GATT server.
... [presenting the GATT-Based profile hierarchy]
... The point is that capabilities can change based on the profile
... So far, the profile could not be changed.
... The Web Bluetooth Community Group at W3C is developing a specification based on the GATT profile.
... There is already a version available. The spec is based on BLE (low-energy) provided through GATT

Johannes: Thank you Nimura-san!
... The GATT profile allows you to map a REST architecture into Bluetooth, is that correct?

Kazuaki: to some extent. Key/value pairs is possible.
... Some more thinking needed.

Johannes: possible to have retrieve/update key/value pairs?

Kazuaki: yes.

Johannes: is there a way from the server to actively notify a client? A pub-sub model?

Kazuaki: servers as clients mean a device. It is much more primitive than the server you might have in mind.
... GATT only deals with devices.

Johannes: A device usually has both client and server implementations?

Kazuaki: Usually, a device has server capabilities.

Johannes: I will add this to out landscape document, thanks!

Sensei-IoT (IEEE P21451-4)

[William presenting slides on Sensei/IoT]

William: Chairman of join effort between ISO/IEC/IEEE on transport shipping.
... Our group is called P21451-4, a.k.a. Sensei/IoT

-> http://sensei-iot.org Sensei/IoT

William: One of the things that I will keep mentioning today is XMPP. We're all using XMPP, e.g. in WebEx right now.
... In the evolution of the Web, we're sort of at Web 2.0 based on HTTP. As we're moving to Web 3.0, more semantic interactions arise.
... We're moving towards the "Intelligent Web" (Web 4.0).
... The XMPP protocol, maintained by the XMPP Standards Foundation, was developed way back in the 90s by the Jabber Foundation.
... Many IoT protocols [presenting a short relevant list]
... We have to work with these different protocols.
... Our standard is making use of various other standards.
... Our working group is co-sponsored by Kang Lee, NIST, and Dan Kimball, SRA from IEEE and ISO/IEC respectively.
... About the unique identification: based on the JID (Jabber IDentifier) used in XMPP. It looks more like an email.
... It adds a layer of security and authentication.
... Also the possibility to define additional resources on that identifier which hasn't be used a lot by people using XMPP up until now.
... This allows to identify Things with a globally unique ID.
... Sensei/IoT is technology agnostic and protocol independent. It makes use of TLS, built into the protocol to encrypt the data traffic. The XMPP protocol is also firewall-friendly.
... The XML in the XMPP is used for conversation between the devices.
... The technology can use a Service Broker as intermediary to share data between devices, applications, users.
... Lots of different security aspects.
... Meta data isolation protects against cyber-attacks.
... It can be used to map to legacy protocols and offer additional protections.
... There are extensions known as IoT XEPs.
... [showing a list of extensions]
... I'm only going to touch on a subset of these extensions, but will pass them over to you.
... One of the key things that we recently added, as requested by IANA, is a new URI scheme
... This completes the unique id of the Thing. There will be things registries across the planet where you can learn about things.
... [showing an example of a discovery request]
... Through discovery, you can ask whether the service supports a particular set of features.
... The reply includes some flag about interoperability. We're going to define what interoperability means when mapped to the different existing possibilities.
... [showing an example of a request to a particular sensor value]
... The request could have requested more than one sensor value at a time.
... XMPP is a service-oriented architecture so can be used for P2P communication.
... Scaling can be done into the cloud. With regular technology, you would setup a VPN. With XMPP, you would end up with a federated cloud architecture.
... It really doesn't matter what type of communication you have to share information. We are able to bridge private clouds and public clouds.
... Another block of our standard is IoT provisioning. Many other systems are starting to support XEPs. You will be able to download the libraries on our Website. When systems are interconnecting, you can share your systems through UPnP, CoAP, etc.
... TeliaSonera is deploying a system based on this.
... You'll be able to share HTTP over XMPP, so HTTP/CoAP traffic can leverage the XMPP architecture.
... This can be used to communicate to services behind a firewall for instance.
... You may not really whether the Web server you're communicating with can be trusted, so requiring this server to register will help. New URIs to appear in a near future for that.
... EXI allow you to enable stream compression.
... EXI was another work done jointly with Japan.
... A final XEP that I'd like to introduce here is the Concentrator which allows you to connect various sensors from legacy systems (e.g. PLCs)
... For those familiar with industrial protocols, OPC UA can be integrated through XMPP.
... A lot of people may be familiar with the P21451 family of standards.
... Relying on these standards was really useful for our work.
... Some parts are really impressive.
... e.g. the notion of "TEDS" which can be used for transducer self-identification and description.
... The TEDS are used basically today in millions of devices (e.g. in airplanes), although people are unaware of them.
... I'm going to stop there. You're welcome to join any of our meeting. It's not a close group as opposed to regulary ISO/IEEE groups.

Johannes: Thanks a lot for this presentation.
... I see a lot of topic in common with what we're doing here.

Joerg: Is your main focus about XEP specifications?

William: The document that we're preparing is being added to the P21451-1-4 standard. Different parts, some of them more ready than others.
... A number of the things I presented are new as well (to the point that you may be the first ones to hear about some of them)
... In many respects, although you can use these standards directly, we see the main interest as providing the ability to bridge between different protocols.

Joerg: We started with use cases on our side. Do you have some sort of use cases collection?

William: A lot of use cases were there
... [showing some on the screen, to create an instant infrastructure when there is none, also with transportation, smart grids...]
... We started out with existing use cases.
... XMPP has facilitated the addressing of many initial concerns related to security.

Johannes: you mentioned that one of your focus work is also on interoperability. Could the models and interactions you're using in XEPs be mapped to HTTP and other protocols?

William: Yes. The XMPP Concentrator is a separate part of our work that defines how to do the mapping. Useful for people such as TeliaSonera.

-> http://www.iot/teliasonera.com/ TeliaSonera provisioning server

William: working on the concentrator as the part 3 document.
... Communication with an OPC server is commonly used today. People are building these abstractions so that you can access the XMPP data.
... I will send over the slides later today

Johannes: Thank you very much for the presentation, William!
... Also thanks to Nimura-san for the GATT presentation and Francois for scribing.
... See you next week at the F2F!

[Call adjourned]

Summary of Action Items

[End of minutes]

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