This document discusses enabling physical mashups by connecting embedded devices to the internet. It proposes making devices' functionality available as web resources using RESTful interfaces. This would allow devices to be discovered and composed into physical mashups similarly to how online services are combined in web mashups. The document presents a case study integrating a visual mashup editor with web-enabled devices and discusses requirements for fully supporting physical mashups, such as different user interfaces, semantic device descriptions, and event-based interactions. It introduces a framework for executing physical mashups through REST APIs and workflow engines.

1. Mashing Up Your Web-Enabled Home
Enabling Physical Mashups in a
Dominique Guinard, SAP Research Zurich & ETH Zurich
Touch the Web 2010 @ ICWE Vienna
06.07.2010

2. [http://www.flickr.com/photos/moragcasey/]
Web of Things? Physical Mashups?
1. MOTIVATION

3. Embedded Devices Invade us!
• Emergence of the
physical Web,
everyday devices:
– Getting Ubiquitous
– Getting Connected

4. What if we Could Recompose
Them as we Wish?
• Easing the currently
complicated
development.
• Creating a re-
useable/composable
physical world.
• From Web mashups
to physical
mashups.

5. Towards Physical Mashups
REST
REST URL
REST
PHP
JavaScript JavaScript
[http://www.pachube.com] [http://www.webothings.com/energievisible] [http://www.clickscript.ch]

6. Contribution
• Methodology for Web-enabling things. [GuiWoT10]
• Discussing the requirements of physical
mashups.
• Introducing a Web framework supporting
physical mashup editors.
[GuiWoT10] Dominique Guinard, Vlad Trifa, Erik Wilde
Architecting a Mashable Open World Wide Web of
Things, Technical Report No 663, Institude for Pervasive
Computing, ETH Zurich, February 2010.

7. Today’s Menu
1. Motivation
2. Enabeling a Web of
Things
3. Case-study :
Clickscript
4. Discussing the
requirements of physical
[http://www.flickr.com/photos/lessio/1346732230/] mashups.
5. A Physical Mashup
Framework.

8. [http://www.flickr.com/photos/julianbleecker]
Push the Web down to devices!
2. ENABLEING A WEB OF THINGS

9. Integrating Smart Things to the Web
• Connecting them to the Internet:
– Directly: IPv6 Lowpan
– Indirectly: Through reverse proxies (smart gateways).
• “RESTful” Things:
– Functionality as resources:
• BASE_URI/sunspot/sensors/light
– Serving several linked representations:
• HTML for browsability,
• XML / JSON for integration,
• ATOM for aggregation.
– Using HTTP as an application protocol:
• GET, POST, PUT, DELETE,
[GuiWoT10] Dominique Guinard, Vlad Trifa, Erik Wilde
• Error codes, Content negotiation. Architecting a Mashable Open World Wide Web of
Things, Technical Report No 663, Institude for Pervasive
Computing, ETH Zurich, February 2010.

10. Example: RESTful SunSPOTs
• Web-enabling the
Sun SPOT platform:
– All sensors and
actuators become
resources.
• Two
implementation:
– Web-server on the
nodes.
[http://www.sunspotworld.com] – Web-server on the
gateway.
[GuiSpot09] Dominique Guinard, Vlad Trifa, Thomas
Pham, Olivier Liechti. Towards Physical Mashups in the
Web of Things. Proceedings of IEEE INSS 2009

11. [http://www.flickr.com/photos/lpettinati/]
Trying out physical mashups
3. CASE STUDY: CLICKSCRIPT

12. Demo
Adapting a Mashup Editor
• Clickscript:
– Javascript
(JQuery / DOJO)
based visual
language.
• Added wrappers
[http://www.clickscript.ch] for WoT devices:
– RFID, SunSPOT,
Ploggs.

13. [http://www.flickr.com/photos/sharynmorrow/]
What do we need for physical mashups to become reality?
4. DISCUSSING REQUIREMENTS

14. Requirements for supporting
Physical Mashups (1/3)
• R1: Support for several UIs and modalities:
– Domain specific editors (e.g. energy,
security, etc.).
– Beyond the desktop (e.g. mobile).
– Ideally through a RESTful API.
Mashup
Editor
Mashup
API Mashup
Framework
Mashup
Editor

15. Requirements for supporting
Physical Mashups (2/3)
• R2: Support for Described Things:
– REST is a good start but not enough.
– Describe for humans (search) and machines
(discovery).
– Supporting semantic service discovery:
• RDF(a), Microformats, Microdata, etc.
RDFa Discovery
Module
Mashup
Framework
Microformat

16. Requirements for supporting
Physical Mashups (3/3)
• R3: Support for Event-Based Mashups:
– Many “things” are naturally event-based (e.g.
sensors).
– Pull for control, push for monitoring.
– HTTP callbacks (Web Hooks), PuSH, etc.
Editors
GW Web Hook PuSH
Listener Hub
Mashup
Framework Editors
Hub Web Socket
PuSH Client
Server

17. [www.flickr.com/photos/docman ]
Towards Supporting Real-World Mashup Editors
5. A Physical Mashup
Framework

18. Concept

19. Features of the Framework
Workflow Engine:
• Execute the mashups (wait,
–start, stop)
Supports REST & WS-* things.
–
Supporting long running
–workflows.
Using on Ruote.
–
Discovery Component:
• Things “crawler”
–
RDFa Descriptions
–
REST API:
• Create mashups with HTTP.
–
Mashup Entry Point:
• Manage the mashup lifecycle
–with REST.

20. Editor on Top :
Energy Mobile Mashup Editor
• Energy aware mashups:
– « Turn the heating off
when I’m more than two
KMs away from home ».
• Wizard-based:
– Scan tags (QR)
– Setup rules
– Create actions:
• Physical (thing)
• Virtual (e.g. xmpp,
Atom, Twitter, SMS,
etc.)

21. [http://www.flickr.com/photos/parmiter/]
Where do we go from here?
OPEN CHALLENGES

22. Challenges Towards Physical Mashups
• Discovering/searching things and
their services:
– We use a “proprietary” RDFa
description.
– Standard? Currently experimenting
using Microformats.
• Scalability? Usefulness?
– Need for qualitative/quantitative
evaluation.

23. Thanks a lot for your
attention
www.webofthings.com
• Contact:
– Dominique Guinard
– dguinard a t ethz.ch
– www.guinard.org
• Special thanks to:
– Azulena Aguilar.
23

24. Backup Slides

25. Web of Things (WoT)?
Social Web
Internet of
Real-time Web
Things
Programmable
Semantic Web Web
Web of Things

26. I. Connecting Embedded Devices
to the Internet
n
No
6 IP es
IP v a n de
vi c
p
lo w
[TrifaGW] Vlad Trifa, Samuel Wieland, Dominique Guinard, Thomas Michael
Bohnert: Design and Implementation of a Gateway for Web-based Interaction
and Management of Embedded Devices.
Proceedings of the 2nd International Workshop on Sensor Network
Engineering (IWSNE 09). Marina del Rey, CA, USA, June 2009