Internet Architecture Board (IAB)                             J. Jimenez
Request for Comments: 8477                                 H. Tschofenig
Category: Informational                                        D. Thaler
ISSN: 2070-1721                                             October 2018


               Report from the Internet of Things (IoT)
           Semantic Interoperability (IOTSI) Workshop 2016

Abstract

  This document provides a summary of the "Workshop on Internet of
  Things (IoT) Semantic Interoperability (IOTSI)", which took place in
  Santa Clara, California March 17-18, 2016.  The main goal of the
  workshop was to foster a discussion on the different approaches used
  by companies and Standards Developing Organizations (SDOs) to
  accomplish interoperability at the application layer.  This report
  summarizes the discussions and lists recommendations to the standards
  community.  The views and positions in this report are those of the
  workshop participants and do not necessarily reflect those of the
  authors or the Internet Architecture Board (IAB), which organized the
  workshop.  Note that this document is a report on the proceedings of
  the workshop.  The views and positions documented in this report are
  those of the workshop participants and do not necessarily reflect IAB
  views and positions.

Status of This Memo

  This document is not an Internet Standards Track specification; it is
  published for informational purposes.

  This document is a product of the Internet Architecture Board (IAB)
  and represents information that the IAB has deemed valuable to
  provide for permanent record.  It represents the consensus of the
  Internet Architecture Board (IAB).  Documents approved for
  publication by the IAB are not candidates for any level of Internet
  Standard; see Section 2 of RFC 7841.

  Information about the current status of this document, any errata,
  and how to provide feedback on it may be obtained at
  https://www.rfc-editor.org/info/rfc8477.










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Copyright Notice

  Copyright (c) 2018 IETF Trust and the persons identified as the
  document authors.  All rights reserved.

  This document is subject to BCP 78 and the IETF Trust's Legal
  Provisions Relating to IETF Documents
  (https://trustee.ietf.org/license-info) in effect on the date of
  publication of this document.  Please review these documents
  carefully, as they describe your rights and restrictions with respect
  to this document.

Table of Contents

  1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   3
  2.  Terminology . . . . . . . . . . . . . . . . . . . . . . . . .   4
  3.  What Problems to Solve  . . . . . . . . . . . . . . . . . . .   5
  4.  Translation . . . . . . . . . . . . . . . . . . . . . . . . .   7
  5.  Dealing with Change . . . . . . . . . . . . . . . . . . . . .   9
  6.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .  10
  7.  Security Considerations . . . . . . . . . . . . . . . . . . .  10
  8.  Collaboration . . . . . . . . . . . . . . . . . . . . . . . .  11
  9.  Informative References  . . . . . . . . . . . . . . . . . . .  12
  Appendix A.  Program Committee  . . . . . . . . . . . . . . . . .  14
  Appendix B.  Accepted Position Papers . . . . . . . . . . . . . .  14
  Appendix C.  List of Participants . . . . . . . . . . . . . . . .  17
  IAB Members at the Time of Approval . . . . . . . . . . . . . . .  18
  Acknowledgements  . . . . . . . . . . . . . . . . . . . . . . . .  18
  Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .  18






















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1.  Introduction

  The Internet Architecture Board (IAB) holds occasional workshops
  designed to consider long-term issues and strategies for the
  Internet, and to suggest future directions for the Internet
  architecture.  The investigated topics often require coordinated
  efforts from many organizations and industry bodies to improve an
  identified problem.  One of the targets of the workshops is to
  establish communication between relevant organizations, especially
  when the topics are out of the scope of the Internet Engineering Task
  Force (IETF).  This long-term planning function of the IAB is
  complementary to the ongoing engineering efforts performed by working
  groups of the IETF.

  With the expansion of the Internet of Things (IoT), interoperability
  becomes more and more important.  Standards Developing Organizations
  (SDOs) have done a tremendous amount of work to standardize new
  protocols and profile existing protocols.

  At the application layer and at the level of solution frameworks,
  interoperability is not yet mature.  Particularly, the work on data
  formats (in the form of data models and information models) has not
  seen the same level of consistency throughout SDOs.

  One common problem is the lack of an encoding-independent
  standardization of the information, the so-called information model.
  Another problem is the strong relationship between data formats and
  the underlying communication architecture, such as a design in Remote
  Procedure Call (RPC) style or a RESTful design (where REST refers to
  Representational State Transfer).  Furthermore, groups develop
  solutions that are very similar on the surface but differ slightly in
  their standardized outcome, leading to interoperability problems.
  Finally, some groups favor different encodings for use with various
  application-layer protocols.

  Thus, the IAB decided to organize a workshop to reach out to relevant
  stakeholders to explore the state of the art and identify commonality
  and gaps [IOTSIAG] [IOTSIWS].  In particular, the IAB was interested
  to learn about the following aspects:

  o  What is the state of the art in data and information models?  What
     should an information model look like?

  o  What is the role of formal languages, such as schema languages, in
     describing information and data models?

  o  What is the role of metadata, which is attached to data to make it
     self-describing?



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  o  How can we achieve interoperability when different organizations,
     companies, and individuals develop extensions?

  o  What is the experience with interworking various data models
     developed from different groups, or with data models that evolved
     over time?

  o  What functionality should online repositories for sharing schemas
     have?

  o  How can existing data models be mapped against each other to offer
     interworking?

  o  Is there room for harmonization, or are the use cases of different
     groups and organizations so unique that there is no possibility
     for cooperation?

  o  How can organizations better work together to increase awareness
     and information sharing?

2.  Terminology

  The first roadblock to interoperability at the level of data models
  is the lack of a common vocabulary to start the discussion.
  [RFC3444] provides a starting point by separating conceptual models
  for designers, or "information models", from concrete detailed
  definitions for implementers, or "data models".  There are concepts
  that are undefined in that RFC and elsewhere, such as the interaction
  with the resources of an endpoint, or "interaction model".
  Therefore, the three "main" common models that were identified were:

  Information Model
     An information model defines an environment at the highest level
     of abstraction and expresses the desired functionality.
     Information models can be defined informally (e.g., in prose) or
     more formally (e.g., Unified Modeling Language (UML), Entity-
     Relationship Diagrams, etc.).  Implementation details are hidden.

  Data Model
     A data model defines concrete data representations at a lower
     level of abstraction, including implementation- and protocol-
     specific details.  Some examples are SNMP Management Information
     Base (MIB) modules, World Wide Web Consortium (W3C) Thing
     Description (TD) Things, YANG modules, Lightweight Machine-to-
     Machine (LwM2M) Schemas, Open Connectivity Foundation (OCF)
     Schemas, and so on.





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  Interaction Model
     An interaction model defines how data is accessed and retrieved
     from the endpoints, being, therefore, tied to the specific
     communication pattern that the system has (e.g., REST methods,
     Publish/Subscribe operations, or RPC calls).

  Another identified terminology issue is the semantic meaning overload
  that some terms have.  The meaning can vary depending on the context
  in which the term is used.  Some examples of such terms are as
  follows: semantics, models, encoding, serialization format, media
  types, and encoding types.  Due to time constraints, no concrete
  terminology was agreed upon, but work will continue within each
  organization to create various terminology documents.  The
  participants agreed to set up a GitHub repository [IOTSIGIT] for
  sharing information.

3.  What Problems to Solve

  The participants agreed that there is not simply a single problem to
  be solved but rather a range of problems.  During the workshop, the
  following problems were discussed:

  o  Formal Languages for Documentation Purposes

  To simplify review and publication, SDOs need formal descriptions of
  their data and interaction models.  Several of them use a tabular
  representation found in the specification itself but use a formal
  language as an alternative way of describing objects and resources
  for formal purposes.  Some examples of formal language use are as
  follows.

  The Open Mobile Alliance (OMA), now OMA SpecWorks, used an XML Schema
  [LWM2M-Schema] to describe their object and resource definitions.
  The XML files of standardized objects are available for download at
  [OMNA].

  The Bluetooth Special Interest Group (SIG) defined Generic Attribute
  Profile (GATT) services and characteristics for use with Bluetooth
  Smart/Low Energy.  The services and characteristics are shown in a
  tabular form on the Bluetooth SIG website [SIG] and are defined as
  XML instance documents.

  The Open Connectivity Foundation (OCF) uses JSON Schemas to formally
  define data models and RESTful API Modeling Language (RAML) to define
  interaction models.  The standard files are available online at
  <oneIoTa.org>.





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  The AllSeen Alliance uses AllJoyn Introspection XML to define data
  and interaction models in the same formal language, tailored for
  RPC-style interaction.  The standard files are available online on
  the AllSeen Alliance website, but both standard and vendor-defined
  model files can be obtained by directly querying a device for them at
  runtime.

  The World Wide Web Consortium (W3C) uses the Resource Description
  Framework (RDF) to define data and interaction models using a format
  tailored for the web.

  The Internet Engineering Task Force (IETF) uses YANG to define data
  and interaction models.  Other SDOs may use various other formats.

  o  Formal Languages for Code Generation

  Code-generation tools that use formal data and information modeling
  languages are needed by developers.  For example, the AllSeen Visual
  Studio Plugin [AllSeen-Plugin] offers a wizard to generate code based
  on the formal description of the data model.  Another example of a
  data modeling language that can be used for code generation is YANG.
  A popular tool to help with code generation of YANG modules is pyang
  [PYANG].  An example of a tool that can generate code for multiple
  ecosystems is OpenDOF [OpenDOF].  Use cases discussed for code
  generation included easing development of server-side device
  functionality, clients, and compliance tests.

  o  Debugging Support

  Debugging tools are needed that implement generic object browsers,
  which use standard data models and/or retrieve formal language
  descriptions from the devices themselves.  As one example, the nRF
  Bluetooth Smart sniffer from Nordic Semiconductor [nRF-Sniffer] can
  be used to display services and characteristics defined by the
  Bluetooth SIG.  As another example, AllJoyn Explorer
  [AllJoynExplorer] can be used to browse and interact with any
  resource exposed by an AllJoyn device, including both standard and
  vendor-defined data models, by retrieving the formal descriptions
  from the device at runtime.

  o  Translation

  The working assumption is that devices need to have a common data
  model with a priori knowledge of data types and actions.  However,
  that would imply that each consortium/organization will try to define
  their own data model.  That would cause a major interoperability





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  problem, possibly a completely intractable one given the number of
  variations, extensions, compositions, or versioning changes that will
  happen for each data model.

  Another potential approach is to have a minimal amount of information
  on the device to allow for a runtime binding to a specific model, the
  objective being to require as little prior knowledge as possible.

  Moreover, gateways, bridges and other similar devices need to
  dynamically translate (or map) one data model to another one.
  Complexity will increase as there are also multiple protocols and
  schemas that make interoperability harder to achieve.

  o  Runtime Discovery

  Runtime discovery allows IoT devices to exchange metadata about the
  data, potentially along with the data exchanged itself.  In some
  cases, the metadata not only describes data but also the interaction
  model as well.  An example of such an approach has been shown with
  Hypermedia as the Engine of Application State (HATEOAS) [HATEOAS].
  Another example is that all AllJoyn devices support such runtime
  discovery using a protocol mechanism called "introspection", where
  the metadata is queried from the device itself [AllSeen].

  There are various models, whether deployed or possible, for such
  discovery.  The metadata might be extracted from a specification,
  looked up on a cloud repository (e.g., oneIoTa for OCF models),
  looked up via a vendor's site, or obtained from the device itself
  (such as in the AllJoyn case).  The relevant metadata might be
  obtained from the same place or different pieces might be obtained
  from different places, such as separately obtaining (a) syntax
  information, (b) end-user descriptions in a desired language, and (c)
  developer-specific comments for implementers.

4.  Translation

  In an ideal world where organizations and companies cooperate and
  agree on a single data model standard, there is no need for gateways
  that translate from one data model to another one.  However, this is
  far from reality today, and there are many proprietary data models in
  addition to the already standardized ones.  As a consequence,
  gateways are needed to translate between data models.  This leads to
  (n^2)-n combinations, in the worst case.

  There are analogies with gateways back in the 1980s that were used to
  translate between network layer protocols.  Eventually, IP took over,
  providing the necessary end-to-end interoperability at the network
  layer.  Unfortunately, the introduction of gateways leads to the loss



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  of expressiveness due to the translation between data models.  The
  functionality of IP was so valuable in the market that advanced
  features of other networking protocols became less attractive and
  were not used anymore.

  Participants discussed an alternative that they called a "red star",
  shown in Figure 1, where data models are translated to a common data
  model shown in the middle.  This reduces the number of translations
  that are needed down to 2n (in the best case).  The problem, of
  course, is that everyone wants their own data model to be the red
  star in the center.

     +-----+                                        +-----+
     |     |                                        |     |
     |     |  --                                 -- |     |
     |     |    --                             --   |     |
     +-----+      --                         --     +-----+
                    --                    ---
                      --                --
                        --            --
                          --        --
       ---                  -- A  --                  ---
      /   \                ___/ \___                 /   \
     |     | ---------------',   .'---------------  |     |
      \   /                 /. ^ .\                  \   /
       ---                 /'     '\                  ---
                          --        --
                        --            --
                      --                --
                    --                    --
                  --                        --
         /\     --                            --     /\
        /  \  --                                --  /  \
       /    \                                      /    \
      /      \                                    /      \
     /--------\                                  /--------\

           Figure 1: The "Red Star" in Data/Information Models

  While the workshop itself was not a suitable forum to discuss the
  design of such translation in detail, several questions were raised:

  o  Do we need a "red star" that does everything, or could we design
     something that offers a more restricted functionality?

  o  How do we handle loss of data and functionality?





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  o  Should data be translated between data models, or should data
     models themselves be translated?

  o  How can interaction models be translated?  They need to be dealt
     with in addition to the data models.

  o  Many (if not all) data and interaction models have some bizarre
     functionality that cannot be translated easily.  How can those be
     handled?

  o  What limitations are we going to accept in these translations?

  The participants also addressed the question of when translation
  should be done.  Two use cases were discussed:

  (a)  Design time: A translation between data model descriptions, such
       as translating a YANG module to a RAML/JSON model, can be
       performed once, during design time.  A single information model
       might be mapped to a number of different data models.

  (b)  Run time: Runtime translation of values in two standard data
       models can only be algorithmically done when the data model on
       one side is algorithmically derived from the data model on the
       other side.  This was called a "derived model".  It was
       discussed that the availability of runtime discovery can aid in
       semantic translation, such as when a vendor-specific data model
       on one side of a protocol bridge is resolved and the translator
       can algorithmically derive the semantically equivalent vendor-
       specific data model on the other side.  This situation is
       discussed in [BridgeTaxonomy].

  The participants agreed that algorithm translation will generally
  require custom code whenever one is translating to anything other
  than a derived model.

  Participants concluded that it is typically easier to translate data
  between systems that follow the same communication architecture.

5.  Dealing with Change

  A large part of the workshop was dedicated to the evolution of
  devices and server-side applications.  Interactions between devices
  and services and how their relationship evolves over time is
  complicated by their respective interaction models.

  The workshop participants discussed various approaches to deal with
  change.  In the most basic case, a developer might use a description
  of an API and implement the protocol steps.  Sometimes, the data or



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  information model can be used to generate code stubs.  Subsequent
  changes to an API require changes on the clients to upgrade to the
  new version, which requires some development of new code to satisfy
  the needs of the new API.

  These interactions could be made machine understandable in the first
  place, enabling for changes to happen at runtime.  In that scenario,
  a machine client could discover the possible interactions with a
  service, adapting to changes as they occur without specific code
  being developed to adapt to them.

  The challenge seems to be to code the human-readable specification
  into a machine-readable format.  Machine-readable languages require a
  shared vocabulary to give meaning to the tags.

  These types of interactions are often based on the REST architectural
  style.  Its principle is that a device or endpoint only needs a
  single entry point, with a host providing descriptions of the API
  in-band by means of web links and forms.

  By defining IoT-specific relation types, it is possible to drive
  interactions through links instead of hard-coding URIs into a RESTful
  client, thus making the system flexible enough for later changes.
  The definition of the basic hypermedia formats for IoT is still a
  work in progress.  However, some of the existing mechanisms can be
  reused, such as resource discovery, forms, or links.

6.  IANA Considerations

  This document has no IANA actions.

7.  Security Considerations

  There were two types of security considerations discussed: use of
  formal data models for security configuration and security of data
  and data models in general.

  It was observed that the security assumptions and configuration, or
  "security model", varies by ecosystem today, making the job of a
  translator difficult.  For example, there are different types of
  security principals (e.g., user vs. device vs. application), the use
  of Access Control Lists (ACLs) versus capabilities, and what types of
  policies can be expressed, all vary by ecosystem.  As a result, the
  security model architecture generally dictates where translation can
  be done.






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  One approach discussed was whether two endpoints might be able to use
  some overlay security model across a translator between two
  ecosystems, which only works if the two endpoints agree on a common
  data model for their communication.  Another approach discussed was
  simply having a translator act as a trusted intermediary, which
  enables the translator to translate between different data models.

  One suggestion discussed was either adding metadata into the formal
  data model language or having it accompany the data values over the
  wire, tagging the data with privacy levels.  However, sometimes even
  the privacy level of information might itself be sensitive.  Still,
  it was observed that being able to dynamically learn security
  requirements might help provide better UIs and translators.

8.  Collaboration

  The participants discussed how best to share information among their
  various organizations.  One discussion was around having joint
  meetings.  One current challenge reported was that organizations were
  not aware of when and where each other's meetings were scheduled, and
  sharing such information could help organizations better collocate
  meetings.  To facilitate this exchange, the participants agreed to
  add links to their respective meeting schedules from a common page in
  the IOTSI repository [IOTSIGIT].

  Another challenge reported was that organizations did not know how to
  find each other's published data models, and sharing such information
  could better facilitate reuse of the same information model.  To
  facilitate this exchange, the participants discussed whether a common
  repository might be used by multiple organizations.  The OCF's
  oneIoTa repository was discussed as one possibility, but it was
  reported that its terms of use at the time of the workshop prevented
  this.  The OCF agreed to take this back and look at updating the
  terms of use to allow other organizations to use it, as the
  restriction was not the intent.  <schema.org> was discussed as
  another possibility.  In the meantime, the participants agreed to add
  links to their respective repositories from a common page in the
  IOTSI repository [IOTSIGIT].

  It was also agreed that the [email protected] mailing list would remain
  open and available for sharing information between all relevant
  organizations.









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9.  Informative References

  [AllJoynExplorer]
             Microsoft, "AllJoyn".

  [AllSeen]  Thaler, D., "Summary of AllSeen Alliance Work Relevant to
             Semantic Interoperability", 2016, <https://www.iab.org/
             wp-content/IAB-uploads/2016/03/AllSeen-summary-IOTSI.pdf>.

  [AllSeen-Plugin]
             Rockwell, B., "Using the AllJoyn Studio Extension", August
             2015.

  [BridgeTaxonomy]
             Thaler, D., "IoT Bridge Taxonomy", IAB IOTSI
             Workshop 2016, <https://www.iab.org/wp-content/
             IAB-uploads/2016/03/DThaler-IOTSI.pdf>.

  [HATEOAS]  Kovatsch, M., Hassan, Y., and K. Hartke, "Semantic
             Interoperability Requires Self-describing Interaction
             Models: HATEOAS for the Internet of Things", Proceedings
             of the IAB IoT Semantic Interoperability Workshop 2016,
             <https://www.iab.org/wp-content/
             IAB-uploads/2016/03/2016-IAB-HATEOAS.pdf>.

  [IOTSIAG]  IAB, "IoT Semantic Interoperability Workshop Agenda",
             2016,
             <https://www.iab.org/activities/workshops/iotsi/agenda/>.

  [IOTSIGIT]
             "Starting place for the IoT Semantic Interoperability
             Workshop (IOTSI) Information Resource", commit ff21f74,
             July 2018, <https://github.com/iotsi/iotsi>.

  [IOTSIWS]  IAB, "IoT Semantic Interoperability Workshop 2016", 2016,
             <https://www.iab.org/activities/workshops/iotsi/>.

  [LWM2M-Schema]
             OMA, "LWM2M XML Schema - LWM2M Editor Schema", July 2018.

  [nRF-Sniffer]
             Nordic Semiconductor, "nRF Sniffer: Smart/Bluetooth low
             energy packet sniffer".

  [OMNA]     OMA, "OMA LightweightM2M (LwM2M) Object and Resource
             Registry".





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  [OpenDOF]  OpenDOF, "The OpenDOF Project", <https://opendof.org>.

  [PYANG]    "An extensible YANG validator and converter in python",
             commit 15c807f, September 2018,
             <https://github.com/mbj4668/pyang>.

  [RFC3444]  Pras, A. and J. Schoenwaelder, "On the Difference between
             Information Models and Data Models", RFC 3444,
             DOI 10.17487/RFC3444, January 2003,
             <https://www.rfc-editor.org/info/rfc3444>.

  [SIG]      Bluetooth SIG, "GATT Specifications",
             <https://www.bluetooth.com/specifications/gatt>.






































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Appendix A.  Program Committee

  This workshop was organized by the following individuals: Jari Arkko,
  Ralph Droms, Jaime Jimenez, Michael Koster, Dave Thaler, and Hannes
  Tschofenig.

Appendix B.  Accepted Position Papers

  o  Jari Arkko, "Gadgets and Protocols Come and Go, Data Is Forever"

  o  Carsten Bormann, "Noise in Specifications hurts"

  o  Benoit Claise, "YANG as the Data Modelling Language in the IoT
     space"

  o  Robert Cragie, "The ZigBee Cluster Library over IP"

  o  Dee Denteneer, Michael Verschoor, and Teresa Zotti, "Fairhair:
     interoperable IoT services for major Building Automation and
     Lighting Control ecosystems"

  o  Universal Devices, "Object Oriented Approach to IoT
     Interoperability"

  o  Bryant Eastham, "Interoperability and the OpenDOF Project"

  o  Stephen Farrell and Alissa Cooper, "It's Often True: Security's
     Ignored (IOTSI) - and Privacy too"

  o  Christian Groves, Lui Yan, and Yang Weiwei, "Overview of IoT
     semantics landscape"

  o  Ted Hardie, "Loci of Interoperability for the Internet of Things"

  o  Russ Housley, "Vehicle-to-Vehicle and Vehicle-to-Infrastructure
     Communications"

  o  Jaime Jimenez, Michael Koster, and Hannes Tschofenig, "IPSO Smart
     Objects"

  o  David Jones, "IOTDB - interoperability Through Semantic
     Metastandards"

  o  Sebastian Kaebisch and Darko Anicic, "Thing Description as Enabler
     of Semantic Interoperability on the Web of Things"






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  o  Achilleas Kemos, "Alliance for Internet of Things Innovation
     Semantic Interoperability Release 2.0, AIOTI WG03 - IoT
     Standardisation"

  o  Ari Keraenen and Cullen Jennings, "SenML: simple building block
     for IoT semantic interoperability"

  o  Dongmyoung Kim, Yunchul Choi, and Yonggeun Hong, "Research on
     Unified Data Model and Framework to Support Interoperability
     between IoT Applications"

  o  Michael Koster, "Model-Based Hypertext Language"

  o  Matthias Kovatsch, Yassin N.  Hassan, and Klaus Hartke, "Semantic
     Interoperability Requires Self-describing Interaction Models"

  o  Kai Kreuzer, "A Pragmatic Approach to Interoperability in the
     Internet of Things"

  o  Barry Leiba, "Position Paper"

  o  Marcello Lioy, "AllJoyn"

  o  Kerry Lynn and Laird Dornin, "Modeling RESTful APIs with JSON
     Hyper-Schema"

  o  Erik Nordmark, "Thoughts on IoT Semantic Interoperability: Scope
     of security issues"

  o  Open Geospatial Consortium, "OGC SensorThings API: Communicating
     "Where" in the Web of Things"

  o  Jean Paoli and Taqi Jaffri, "IoT Information Model
     Interoperability: An Open, Crowd-Sourced Approach in Three
     Parallel Parti"

  o  Joaquin Prado, "OMA Lightweight M2M Resource Model"

  o  Dave Raggett and Soumya Kanti Datta, "Input paper for IAB Semantic
     Interoperability Workshop"

  o  Pete Rai and Stephen Tallamy, "Semantic Overlays Over Immutable
     Data to Facilitate Time and Context Specific Interoperability"

  o  Jasper Roes and Laura Daniele, "Towards semantic interoperability
     in the IoT using the Smart Appliances REFerence ontology (SAREF)
     and its extensions"




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  o  Max Senges, "Submission for IAB IoT Sematic Interoperability
     workshop"

  o  Bill Silverajan, Mert Ocak and Jaime Jimenez, "Implementation
     Experiences of Semantic Interoperability for RESTful Gateway
     Management"

  o  Ned Smith, Jeff Sedayao, and Claire Vishik, "Key Semantic
     Interoperability Gaps in the Internet-of-Things Meta-Models"

  o  Robert Sparks and Ben Campbell, "Considerations for certain IoT-
     based services"

  o  J.  Clarke Stevens, "Open Connectivity Foundation oneIoTa Tool"

  o  J.  Clarke Stevens and Piper Merriam, "Derived Models for
     Interoperability Between IoT Ecosystems"

  o  Ravi Subramaniam, "Semantic Interoperability in Open Connectivity
     Foundation (OCF) - formerly Open Interconnect Consortium (OIC)"

  o  Andrew Sullivan, "Position paper for IOTSI workshop"

  o  Darshak Thakore, "IoT Security in the context of Semantic
     Interoperability"

  o  Dave Thaler, "IoT Bridge Taxonomy"

  o  Dave Thaler, "Summary of AllSeen Alliance Work Relevant to
     Semantic Interoperability"

  o  Mark Underwood, Michael Gruninger, Leo Obrst, Ken Baclawski, Mike
     Bennett, Gary Berg-Cross, Torsten Hahmann, and Ram Sriram,
     "Internet of Things: Toward Smart Networked Systems and Societies"

  o  Peter van der Stok and Andy Bierman, "YANG-Based Constrained
     Management Interface (CoMI)"














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Appendix C.  List of Participants

     Andy Bierman, YumaWorks
     Carsten Bormann, Uni Bremen/TZI
     Ben Campbell, Oracle
     Benoit Claise, Cisco
     Alissa Cooper, Cisco
     Robert Cragie, ARM Limited
     Laura Daniele, TNO
     Bryant Eastham, OpenDOF
     Christian Groves, Huawei
     Ted Hardie, Google
     Yonggeun Hong, ETRI
     Russ Housley, Vigil Security
     David Janes, IOTDB
     Jaime Jimenez, Ericsson
     Shailendra Karody, Catalina Labs
     Ari Keraenen, Ericsson
     Michael Koster, SmartThings
     Matthias Kovatsch, Siemens
     Kai Kreuzer, Deutsche Telekom
     Barry Leiba, Huawei
     Steve Liang, Uni Calgary
     Marcello Lioy, Qualcomm
     Kerry Lynn, Verizon
     Mayan Mathen, Catalina Labs
     Erik Nordmark, Arista
     Jean Paoli, Microsoft
     Joaquin Prado, OMA
     Dave Raggett, W3C
     Max Senges, Google
     Ned Smith, Intel
     Robert Sparks, Oracle
     Ram Sriram, NIST
     Clarke Stevens
     Ram Subramanian, Intel
     Andrew Sullivan, DIN
     Darshak Thakore, CableLabs
     Dave Thaler, Microsoft
     Hannes Tschofenig, ARM Limited
     Michael Verschoor, Philips Lighting










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IAB Members at the Time of Approval

     Jari Arkko
     Alissa Cooper
     Ted Hardie
     Christian Huitema
     Gabriel Montenegro
     Erik Nordmark
     Mark Nottingham
     Melinda Shore
     Robert Sparks
     Jeff Tantsura
     Martin Thomson
     Brian Trammell
     Suzanne Woolf

Acknowledgements

  We would like to thank all paper authors and participants for their
  contributions and Ericsson for hosting the workshop.

Authors' Addresses

  Jaime Jimenez

  Email: [email protected]


  Hannes Tschofenig

  Email: [email protected]


  Dave Thaler

  Email: [email protected]















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