Towards a Lightweight Standard to Make Things talk Web

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Web Thing Model Towards a Lightweight Standard to Make Things talk Web

W3C WoT Interest Group Meeting, 20.05.2015

Dom Guinard CTO & Co-founder, EVRYTHNG Vlad Trifa R&D Lead and Co-founder, EVRYTHNG


1. THE IOT & THE WOT


What is the Internet of Things?

The Internet of Things is a science primarily focusing on creating the

most complex ways of turning lights on and off.

“ “

[@domguinard]


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Before


After


What is the Web of Things?

The Web of Things is about bringing order in the IoT chaos by

using Web good practices

“ “ [@domguinard]


WoT Web

Web

Web

Web

Web

Web

Internet Of Things Web Of Things

ZigBee

Bluetooth

X10

Bacnet

enOcean


Web of Things

Internet of Things

How do we connect things to the Internet?

How do we connect applications & things?

Applications? §  OSI Layer 7 + §  HTTP, REST,

JSON §  Social nets,

semantics §  Mashups

Networking? §  OSI Layer 4 – §  IPv6lowpan,

EPC, WiFi, BLE Zigbee / 800.15.04

“Uniquely identifiable objects and their virtual representations in an Internet-like structure” §  Auto-ID Labs (K.

Ashton, S. Sarma, F. Mattern) ~ 1999

“Application architecture for physical objects” §  D. Guinard, D.

Raggett, V. Trifa, E. Wilde ~ 2007 http://bit.ly/wot-pub


§  Simplifying Application Development in the Internet of Things

[flickr.com/photos/docman]

Our mission: “Bridging the gap between Things and Web”


Social Web Real-time Web

Semantic Web Programmable Web

Mashups Rest APIs

JSONWeb Services

WebSockets

Web HooksPush Notifications

Facebook Twitter

OAuth

Microdata

RDFaschema.org

Link Headers

RSS/ATOM

The Web of Things

JSON-LD

DelegatedAuthentication


http://bit.ly/wot-phd http://webofthings.org/publications

Initial Web of Things Architecture Framework

Things

Level 4Compose

Node-red

Clickscript

Mashups

Applications

Level 3Share

Social WoT

SSL/TLS

OAuth

ACLDelegated

Authentication

Level 2Find

Link Header

Hateoas

Microdata

Linked Data

JSON-LDREST Crawler

JSONHTML

HTTPNetwork Discovery

Web search

URI / URLLevel 1Access

REST API

Gateways

Web Hooks WebSockets


TOWARDS A WOT STANDARD


Output of experiences / feedback

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BACK TO 2007-2009

@ConnectEvrythng © EVRYTHNG Limited | Confidential | 2013 @EVRYTHNG © EVRYTHNG | Confidential | 2014 http://webofthings.org/publications




GET

GET, PUT

GET, DELETE

Resource Design

Representa0on Design

Interface Design

Implementa0on Strategy

h<p://<DOMAIN>:<PORT>/genericNodes /temperature /sensors /node1

h<p://<DOMAIN>:<PORT>/genericNodes

Source: http://bit.ly/wot-phd


REFERENCE IMPLEMENTATION


Root URL ofRaspberry Pi

devices.webofthings.io/pi

actuators/actuators

LEDs/leds

LED #/{led#}

sensors/sensors

light sensor/light

temperature sensor/temperature

buttons/buttons

acceleration/accel

gyroscope/tilt

/x

/y

/z

/x

/y

/z

/1

/2


DEVICES.WEBOFTHINGS.IO


OK? Why do we need a standard?

§  Web of Things != Internet of Things §  Web is a very good step in the right direction but

§  Web APIs have also created thousands of semi-isolated silos

§  Need for a simple set of rules §  Protocol (REST with JSON over HTTP) §  Resource models (what is in the JSON) §  Support for extensions (semantics, social, etc.)


Goal of the proposal in a nutshell

1.  Blueprints on how to implement APIs for Web Things (REST, HTTP, JSON, etc.)

2.  Standard resources and data-model for the representations

3.  Reference implementation of a compliant gateway


What would this help for?

§  Blueprints = no brainer = faster implementation for companies §  Avoid some horrible options (like WS-* on devices)

§  Automatic generation of User Interfaces including 100% Web-based UIs

§  Automatic generation of mashup building blocks §  API to API integrations §  Automatic, spontaneous integration?


Current proposal in a nutshell


1. WEB THINGS INTEGRATION PATTERNS


Direct Connectivity


Gateway Proxied Connectivity


Cloud Proxied Connectivity


So what?

§  We should not care about whether it’s a Gateway, a Thing or an IoT/WoT Cloud platform they should use the same blueprints, resources, formats and payloads: §  The Web Thing API


2. WEB THINGS REQUIREMENTS


SEE: HTTP://WEBOFTHINGS.GITHUB.IO/WOT-COMPOSE/


Level 0 – MUST

§  R0 - WT MUST be an HTTP 1.1 server §  R0 - WT MUST have a root resource accessible via

an HTTP URL §  R0 - WT MUST support GET, POST, PUT, and

DELETE HTTP verbs §  R0 - WT MUST implement HTTP status codes 200,

400, 500


Level 0: MUST (2/2)

§  R0 - WT MUST support JSON as default representation

§  R0 - WT MUST support UTF8 encoding for requests and responses

§  R0 - WT MUST support GET on its root URL


Level 1: SHOULD

§  R1- WT SHOULD use secure HTTP connections (HTTPS )

§  R1 - WT SHOULD support additional HTTP status codes as needed

§  R1 – WT SHOULD have a “doc” link in their root representation

§  R1 - WT SHOULD support the Web Streams Protocol (explained next)


Level 2: MAY

§  R2 - WT MAY support OPTIONS for each of its resources

§  R2 - WT MAY have a default machine-readable documentation

§  R2 - WT MAY provide additional representation semantic mechanisms (RDF, XML, JSON-LD)

§  R2 - WT MAY offer an HTML interface/representation (UI)


3. WEB THINGS MODEL


From Web Thing to Extended Web Thing

§  Web Thing §  A Web Thing is a digital representation of a physical object

accessible via a RESTful Web API. A Web Thing conforms to this specification if it follows the statements defined in 5. Web Things requirements.

§  Extended Web Thing §  An Extended Web Thing that also supports the REST API and data

model defined in this specification, thus enabling its automatic inclusion in more complex systems.

§  An Extended Web Thing conforms to this specification if it follows the statements defined in §  Web Things requirements §  Web Things model.


Entities §  Client

§  A Client refers to any physical or digital entity that can interact with a Web Thing. This can be a mobile application, a Web browser, a proxy, a desktop application, but also another Web Things (e.g., in the case of Machine to Machine communication).

§  Property §  A Property is a variable of a Web Thing. §  Properties represent the internal state of a Web Thing. Clients can subscribe to properties

to receive a notification message when specific conditions are met (e.g. value of one or more properties changed).

§  Action §  An Action is a function offered by a Web Thing. §  A Client invokes a function on a Web Thing which initiates a state transition by sending it

an Action. Examples of Actions are “open” or “close” for a garage door; “enable” or “disable” for a smoke alarm; “check-in” or “scan” for a bottle of soda or a place. The direction of an Action is from the Client to the Web Thing.


Resources

Provided by: D = Device, G = Gateway, C = Cloud


Models

§  Can be used in JSON, JSON-LD, HTML, etc. §  Web Link Headers §  See http://webofthings.github.io/wot-compose


Subscriptions

§  WebHooks §  WebSockets §  Using protocol

upgrade mechanism


Details & Updates

§  This is work in progress! §  Will be an official W3C submission

§  End of August 2015 §  See the details and up to date version on

§  http://webofthings.github.io/wot-compose/ §  Join the discussion: comment!


WHAT’S NEXT?


Next steps

§  Document now open for comments on: §  http://webofthings.github.io/wot-compose

§  Major protocols integration §  CoAP §  MQTT

§  Need to look at integration points §  Semantic Web (JSON-ld, etc.) §  Social Networks, oAuth, etc. §  Etc.

§  Official W3C Submission end of August 2015


Links §  http://webofthings.org/publications

§  A number of WoT related publications including the initial 2009 WoT architecture implementation papers, books, PhD theses, etc.

§  http://webofthings.org/wot §  International Web of Things Workshop (yearly, 2010 – now)

§  http://evrythng.com §  First WoT cloud platform, free accounts for developers

§  http://twitter.com/webofthings §  WoT twitter community group

§  https://www.linkedin.com/grp/home?gid=1818463 §  Linkedin WoT group

§  http://www.w3.org/WoT/ §  W3C WoT activities


Thank you

Dominique ‘Dom’ Guinard CTO & Co-founder

[email protected] @domguinard

Engineering

Towards a Lightweight Standard to Make Things talk Web