Resource Discovery in IoT: Current Trends, Gap Analysis ...€¦ · Soumya Kanti Datta Research...

Resource Discovery in IoT: Current Trends, Gap Analysis and Future Standardization Aspects

Soumya Kanti DattaResearch Engineer, EURECOM

TF-DI Coordinator in W3C WoT IGEmail: [email protected]

Roadmap

� Introduction

� Current Discovery Landscape

� Gap Analysis from Standards Point-of-View

� Search Engine Based Resource Discovery

� Inputs to SDOs

� Conclusion

11-Dec-2015 Resource Discovery in IoT: Current Trends, Gap Analysis and Future Standardization Aspects

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Introduction: Discovery


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� Search functionalities provided to Humans

�Google

�Yahoo

�Bing

� Search Engine for things?

Source : www.iotdex.com

Two Main Aspects to Consider

� Discovery mechanism is incomplete without retrieving and ranking information.

� Retrieve

� Thing description (including properties and capabilities).

� Thing metadata.

� Rank

� Depending on context rank the retrieved information.


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� Discovery for humans

� Looking for a thing/M2M service providing offline map of Milan.

� Can be assisted by a search engine.

� M2M discovery

� With no human in the loop

� It is one of the challenges.

� E.g. - M2M gateway looking for actuators to set a room temperature (smart living service).

Category 1: Search around ME


- p 5

� This category of discovery includes technologies that allow to discover things around me (in a spatial sense)� NFC

� UriBeacon (Formerly known as Physical Web from Google)

� iBeacon (from Apple)

Sources -

https://www.w3.org/WoT/IG/wiki/Discovery_Categories_and_Tech_Landscape

https://github.com/w3c/wot/blob/master/TF-DI/Interactions.md

Category 2: Search on My Network


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� It covers technologies enabling discovery of things on the network.

� mDNS

� SSDP

Category 3: Searching in a Directory


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� A central directory is used for discovery of things and resources

� Discovery requests are sent to the directory.� CoRE Resource

Directory� XMPP IoT Discovery� SPARQL Endpoints

Category 4: Search Across Peers

� In P2P style discovery, the directory is essentially distributed across the peers.

� Distributed hash tables (DHT) is often used to map the search space into a numeric range and then allocates servers to parts of that range.

� Observation: the technique works well for scale free networks.


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Category 5: Search for Thing Metadata


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� Once a “thing" has been discovered with mentioned mechanisms� next "resources" (thing

metadata) access at thing level

needs to be performed

� Examples� CoAP + CoRE Link Format (for

thing metadata)

� Sensor Observation Service

(SOS): it is a web service which

allows querying sensor

metadata.

Category 6: Semantic Based Search


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� Semantic Enhanced Service Proxy Framework for Internet of Things * � A semantic based framework using the concept of service

advertisement of a smart thing & eases service registration

� The advertisement contains a service metadata including name, id, endpoint, location and semantic annotation link.

� An evaluation of semantic service discovery of a U-city middleware **� It proposes a middleware which performs SD using semantic web

technologies on the contextual information inferred from sensor data.

* http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=5724875

** http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=5440391

Gap Analysis

� No common catalogue to describe the resources, units and domains.

� Synonyms are often not recognized. (Rain and Precipitation sensors)

� Therefore, searching for a resource using a synonym might not discover the

resource.

� No uniform ranking of discovered resources.

� Secure Discovery: how to integrate security mechanisms and access control functions into a discovery framework.

� Lack of uniform mechanism for resource discovery.

� Semantic based discovery is not studied in depth yet.� Extract contexts or key words to be used in discovery.

� How semantics could play a role in maintaining interoperability across IoT platforms.


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Search Engine Based Discovery Framework


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The Three Layers (1/2)

� Proxy layer

� Enable discovery and interaction with smart and legacy things regardless of

communication technology and protocols.

� Discovery layer

� Configuration registry: manages registration, un-registration of things and

provides storage of configurations.

� Indexing API: registered things are indexed to expedite the search

operation.

� Search engine

– Receives the discovery request (keywords/parameters) from clients

– Extracts indices

– Provides look up facility (discovers the matching things)

– Ranks the results based on relevance, availability, access control policies.

� Lifetime: A time period through which resources remain discoverable


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The Three Layers (2/2)

� Service enablement layer

�Exposes discovery layer functionalities through RESTful

web services.

�Enforces strict access control policies.

�Provides subscription and notification facilities.

� Includes semantic components for discovery.

� Incorporate security mechanisms


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Suggestions to SDOs

� Examine how semantics can solve interoperability issues.

� Need uniform and technology independent discovery for higher layer applications.

� Provide guidelines for binding to APIs and protocols for efficient interaction with things.

� Utilize a uniform catalogue of descriptions (as defined in things description) for discovery of things and their metadata.

� Provide means of ranking the discovery results

� When presented to end users or other M2M applications.

� Integrate strong access control policies and security mechanisms.


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Conclusion

� In a nutshell,

� Categorization of discovery mechanisms & interaction patterns.

� Gap analysis from standards perspective

� A search engine based discovery framework

� Suggestions to SDOs.

� A peek into the future works

� Deploying at a cloud to be used in a smart city framework

� Deploy in my soon-to-be smart apartment.


- p 16

Thank you!

� Email: [email protected]

� Telephone: +33658194342

� Twitter: @skdatta2010

� Webpage: http://www.eurecom.fr/en/people/datta-soumya-kanti


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Resource Discovery in IoT: Current Trends, Gap Analysis ...€¦ · Soumya Kanti Datta Research...

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