homeweb: an application framework for web-based smart homes
DESCRIPTION
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 thefunctionality of our system by including a 6LoWPAN-based wireless sensor network inside the home environment, addressing issues such as device discovery and service description. Webtechniques 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.TRANSCRIPT
HomeWeb: An Application Framework for Web-based
Smart Homes
Andreas Kamilaris, Vlad Trifa and Andreas PitsillidesNetworks Research Laboratory, University of Cyprus
University of CyprusMotivation
• 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?
University of CyprusThe Internet for Home Automation
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 gateway app-level gateway UDP, TCP, RESTful
WebCost low high medium low
Installation Overhead low high low low
Connectivity low medium medium high
Security none high medium medium
Matthias Kovatsch et al., Embedding Internet Technology for Home Automation, in Proceedings of ETFA, Bilbao, Spain, September 2010.
“Internet technology, utilizing IPv6, will become the future standard in home automation.”
University of CyprusBackground Information
The WoT practice mainly follows these steps:1. Connect embedded devices to the Internet, through
IPv4 or IPv6.2. Embed Web servers on these devices.3. Model their services in a resource-oriented way.
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.
Directly Web-enabling devices Vs using a Gateway.
University of CyprusBackground Information
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:1. Resources.2. Their names (URIs).3. The links between them.4. Their representations (HTML, JSON, XML).
Resources can be manipulated with:1. GET to retrieve a representation of a resource.2. POST represents an insert or update.3. PUT to alter the state of a resource.4. DELETE to delete resources.
University of CyprusBuilding a Web-based Smart Home
• 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.
University of CyprusHomeWeb Architecture HomeWeb Client Application
Restlet-GWT
Restlet
Web API
Server Application Framework
XML JSON
University of CyprusSystem Architecture
Living Room
Kitchen
Bathroom
Bedroom
Laundry Room
The HomeWebApplication
Resource URI Parameters REST Method Return Value
Temperature - GET text/plain
Humidity - GET text/plain
Illumination - GET text/plain
Leds Color (Red, Green, Blue) PUT text/plain
• IPv6-based Wireless Sensor Network of Telosb sensor motes.• Implementation in TinyOS using blip.• 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.
University of CyprusWeb-enabling Sensor Devices• 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.
University of CyprusWeb-enabling Sensor Devices• 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.
University of CyprusPutting them all together…
University of CyprusPutting them all together…
“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.”
University of CyprusEvaluation
• Multiple family members are interacting concurrently with their home devices through the Web.
• Four sensor devices in a star topology around the base station.
University of CyprusPreliminary Evaluation
0
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
REST SOAP
Tim
e (s
eco
nd
s)
• A multi-hop Web-based IPv6 WSN deployment inside a real smart home environment.
• REST Vs WS-*
University of CyprusConcluding Remarks
• 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.
University of CyprusFuture Work• 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.
