Workshop on IoT Semantic/Hypermedia Interoperability
When: July 15/16, 2017 (weekend before IETF99)
Where: Hilton Prague (IETF meeting hotel), room Berlin/Brussels. Pobřežní 1, Prague, Czech Republic
Remote participation: https://jitsi.tools.ietf.org/WISHI2017 (or see the mailing list for latest information)
Live notes in Google docs: https://goo.gl/P45Z2A
Meeting sponsor: Ericsson.
Please register by June 23rd. Registration and meeting is free of cost (thanks Ericsson) but we need to know number of participants for meeting logistics.
Draft agenda is available here.
One of the interesting questions in the IoT space is the role of hypermedia and/or semantic interoperability for reducing setup overhead and thus TCO, and, more generally, enabling interoperation in the first place.
For example, OMA and IPSO smart objects use the LWM2M object model, which defines a set of pre-structured URI templates and registry of object identifiers with semantics attached. This provides machine-readable representations of the semantics, but self description is not being used much.
OCF has a hypermedia approach with discovery using /oic/res etc., which relies on self-description via pointing to predefined resource types and interface types, which in turn use a number of specification techniques, including JSON schema and RAML.
There is also iot.schema.org, which will allow us to gather further semantic interoperability information in potentially a more granular way.
W3C WoT cares a lot about self-description, with an RDF-based take on semantics and describing things.
T2TRG cares about pulling all this together.
On July 15, we will have a workshop that includes people from these organizations/groups. The focus will be on building a landscape that can benefit from the various approaches, without necessarily papering over all the holes or filling in all the rifts. On July 16, we will have additional time for follow-on work groups that want to make progress on specific issues.
The venue is the Prague Hilton, the same hotel that will host IETF99 directly after that. To further minimize travel, we chose the weekend directly after the July W3C WoT meeting in close by Düsseldorf.
Elements of the agenda:
State of the union
We will have "state of the union" talks from each of the organizations, discussing from a personal perspective where we are on interoperability in the organization and what are the next steps.
Research contributions, prototypes
We issued a call for contributions, with a goal of getting new views and new voices into the mix. This solicits research on the approaches available for building hybrid, overarching systems, as well as some practical systems that are already demonstrating how this could be made to work in practice, such as systems for converting some of the formal notations and/or self descriptions into each other.
The below topics (and any other that come up) could be discussed on Saturday and/or result in more detailed breakouts on Sunday.
The "device ecosystem" oriented SDOs are now increasingly using common protocols and formats (CBOR, CoAP, IPv6) which is creating one narrow waist in the system, and we can look into creating a narrow waist also around semantic interoperability and hypermedia design patterns. Ultimately, it should not matter which device ecosystem(s) you use for your application. The device ecosystems can maintain their focus on intra-op and certification while an over arching web-like layer of interoperability can add more value to all of them.
Now is a good time to start to organize cross-ecosystem interops, where we attempt to orchestrate devices and sources from these different device ecosystems. At this point we need to consider orchestration across applications as well as device to device interoperability.
We have also discussed a lot about conducting more of the actual testing over the Internet. This seems like a good concept to build in from the beginning. What are the tools we need to conduct an online hyper-semantic interop series? Is it staged, from basic to more sophisticated?
This seems to represent the canonical use case for both W3C WoT and iot.schema.org, as well as the various translators and bridges being created.
HTML has a form element that can be used to construct POST request bodies (and other request payloads, such as for PATCH). An M2M equivalent has been lacking for quite some time, although there are proposals. Now that we have FETCH and PATCH (RFC 8132), the need is even more pronounced. What are the next steps towards common Hypermedia "forms", which would help at least T2TRG, OCF, and WoT?
Hypermedia-driven applications in general
T2TRG has a number of drafts documenting how application developers use hypermedia to aid in building thing-to-thing (and thing-to-cloud) systems. Are these complete? What else do we know about that? What about documents from, say, W3C or IPSO?
We now have multiple proposals for data modeling (YANG, CDDL, JSON Schema, JSON Content Rules) as well as ad-hoc metamodels. What are the semantic powers of these modeling approaches? Can we automatically translate between them so we can make models of one ecosystem available for the other ones? How do we tap hidden Gems such as the ZigBee Cluster Library or the Bluetooth GATT specs? What about interaction modeling (also YANG, RAML, Swagger, ...)?