Household appliances are being equipped with embedded micro-controllers and wireless transceivers, offering smart behavior. These augmented appliances form wireless networks and transform residential areas into smart homes. Advancements such as the effective penetration of the Internet in embedded computing and the promising practice of the Web of Things, allow the realization of Web-oriented smart homes. In a previous work, we developed a Web-based application framework for smart homes, supporting concurrent interaction from multiple family members. In this paper, we improve the functionality of our system by including a 6LoWPAN-based wireless sensor network inside the home environment, addressing issues such as device discovery and service description. Web techniques such as HTTP caching and push messaging, facilitate the efficient operation of a fully Web-based smart home. Through a technical evaluation, we show the benefits of directly Web-enabling embedded sensors in terms of performance and energy conservation. The development of a Web-based graphical application abstracts home automation procedure for typical residents. This project has been presented at the 18th International Conference on Telecommunications (ICT 2011), Ayia Napa, Cyprus, May 2011.

1. HomeWeb: An Application
Framework for Web-based
Smart Homes
Andreas Kamilaris, Vlad Trifa and Andreas Pitsillides
Networks Research Laboratory, University of Cyprus

2. Motivation University of Cyprus
• Merging of computing with physical things.
• The Internet can reach out into the real world.
• The Internet of Things.
• Most of the current smart home solutions do not involve
open systems and have been developed to provide
solutions to some application-specic scenarios (medical,
care for the elderly).
• How to interconnect heterogeneous embedded devices?
• What about interoperability? Flexibility?

3. The Internet for Home Automation University of Cyprus
X10 KNX ZigBee IPv6
Network Size 2^8 2^16 2^16 2^64 per subnet
Data Rate 20b/s 9.6kb/s 20-250kb/s 250kb/s...1Gb/s
Interface custom solutions app-level app-level gateway UDP, TCP, RESTful
gateway Web
Cost low high medium low
Installation low high low low
Overhead
Connectivity low medium medium high
Security none high medium medium
“Internet technology, utilizing IPv6, will become the future standard
in home automation.”
Matthias Kovatsch et al., Embedding Internet Technology for Home Automation, in
Proceedings of ETFA, Bilbao, Spain, September 2010.

4. Background Information University of Cyprus
The Web of Things is about reusing well-accepted and
understood Web principles to interconnect the quickly
expanding ecosystem of embedded devices, built into
everyday smart things.
The WoT practice mainly follows these steps:
2. Connect embedded devices to the Internet,
through IPv4 or IPv6.
3. Embed Web servers on these devices.
4. Model their services in a resource-oriented way.
Directly Web-enabling devices Vs using a Gateway.

5. Background Information University of Cyprus
REST is a lightweight architectural style which basically
defines how to use the HTTP application protocol as an
application interface to the world of smart objects.
A Resource-oriented Architecture is about four concepts:
2. Resources.
3. Their names (URIs).
4. The links between them.
5. Their representations (HTML, JSON, XML).
Resources can be manipulated with:
2. GET to retrieve a representation of a resource.
3. POST represents an insert or update.
4. PUT to alter the state of a resource.
5. DELETE to delete resources.

6. Building a Web-based Smart Home University of Cyprus
• Use the Web as a standard, to realize the notion of the
smart home.
• Development of a resource-oriented application framework
for future smart homes.
• Utilization of REST.
• Support for concurrent, multiple Web clients.
• The framework promotes the creation of physical mashups
in any programming language that supports HTTP.

7. HomeWeb Architecture University of Cyprus
HomeWeb Client Application
Restlet-GWT
XML JSON
Web API
Server Application Framework
Restlet

8. System Architecture University of Cyprus
Resource URI Parameters REST Method Return Value
Temperature - GET text/plain
The HomeWeb
Humidity - GET Applicationtext/plain
Bedroom
Illumination - GET text/plain
Leds Color (Red, PUT text/plain
Green, Blue)
Laundry Room Bathroom
• IPv6-based Wireless Sensor Network of Telosb sensor motes.
Living Room
• Implementation in TinyOS using blip. Kitchen
• Each sensor is a small Web server, which offers sensing
services through a RESTful interface.
• All interactions with embedded devices are done via standard
HTTP requests.

9. Web-enabling Sensor Devices University of Cyprus
• Device Discovery:
• Multicast Discovery Protocol.
• Similar to WS-Discovery.
• Transmit a single URL instead of a heavy
SOAP/XML payload.
• Service Description:
• Web Applications Description Language (WADL).
• Similar to WSDL.
• An XML-based language that provides a machine-
readable description of HTTP-based Web
applications.

10. Web-enabling Sensor Devices University of Cyprus
• Web Messaging for Event-driven Scenarios:
• Pull Vs Push.
• Client-server model not appropriate for event-driven
scenarios.
• RESTful Message System (RMS) is a push-based,
lightweight publish/subscribe messaging, suited for
embedded devices.
• HTTP Caching:
• Integrate a Web cache in HomeWeb framework.
• Works only for GET requests using the expiration
model for determining freshness of resources.

11. Putting them all together… University of Cyprus

12. Putting them all together… University of Cyprus
“If the illumination in the living room is less than 50% and the
temperature in the kitchen is greater than 25 degrees, then turn
on the red led of sensor7 and the green led of sensor6.”

13. Evaluation University of Cyprus
• Multiple family members are interacting concurrently with
their home devices through the Web.
• Four sensor devices in a star topology around the base
station.

14. Preliminary Evaluation University of Cyprus
1.6
1.4
1.2
Time (seconds)
1
0.8
0.6
0.4
0.2
0
REST SOAP
• A multi-hop Web-based IPv6 WSN deployment inside a real
smart home environment.
• REST Vs WS-*

15. Concluding Remarks University of Cyprus
• The Web has the potential to become a standard in home
automation.
• An IPv6-based WSN installation in home area networks is
feasible and it offers acceptable performance.
• The application of Web technologies such as HTTP caching
and push techniques in the WSN domain can improve
overall performance.
• Wide-scale connectivity and interoperability are guaranteed.

16. Future Work University of Cyprus
• More thorough evaluation.
• Incorporate more advanced technology in HomeWeb
(residential smart meters, lighting/HVAC control).
• Towards the design of energy-efficient, sustainable, flexible
and secure Web-based smart homes.
• Web-based smart homes as real-time platforms, to engage
people to sense and shape their urban environment, for the
vision of a real-time, digital city*.
* Andreas Kamilaris, Nicolas Iannarilli, Vlad Trifa, and Andreas Pitsillides. Bridging the Mobile
Web and the Web of Things in Urban Environments. In Urban Internet of Things Workshop, at
IoT 2010, November 2010.

17. Thanks for your attention!
Contact Details: Andreas Kamilaris (camel9@gmail.com)