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ISS: The Interactive Smart Home Simulator
Tam Van Nguyen, Student Member, IEEE, Jin Gook Kim and Deokjai Choi
Department of Computer Engineering, Chonnam National University
300 Yongbong-dong, Bukgu, Kwangju, 500-757, Korea
Email: vantam@gmail.com, kimjingook11@gmail.com, dchoi@chonnam.ac.kr
Abstract Digital homes provide the best services to home’s
occupants by using modern devices, home appliances that
integrate transparently and simplify usability in the home.
However, the realization in the real environment is difficult and
takes a long time from building the scratch. Thus, to support the
implementation in the real smart home, it is necessary to
demonstrate that thing can be done in the simulator which deals
with virtual appliances and devices models the real smart home
environment. In this paper, we propose ISS, an Interactive Smart
home Simulator system focusing on controlling and simulating the
behavior of an intelligent house. The developed system aims to
provide architects, designers a simulation and useful tool for
understanding the interaction between environment, people and
the impact of embedded and pervasive technology on in daily life.
In this research, the smart house is considered as an environment
made up of independent and distributed devices interacting to
support user’s goals and tasks. Therefore, by using ISS, the
developer can realize the relationship among virtual home space,
surrounded environment, users and home appliances.
Keywords
Smart Home Simulator, Ubiquitous Computing,
Context Aware.
1. Introduction
Nowadays pervasive computing is gradually changing our
daily lifestyle. The new trend of computing, ubiquitous
computing provides access to information and computing
resources for users at anytime and anywhere [1, 2]. Since home
is the place where everybody lives, smart home aim to provide
the best services to home habitants [3, 4]. In this environment,
applications must be self-adaptive to the environment within
which they operate.
For researchers, it is difficult to work in the real smart
home since home appliances are very expensive. Besides,
collecting information from sensors, reasoning from known
databases, and determining appropriate activities are the main
steps for self-adaptive applications. Actually, the main key to
those applications is context information. However, there
should be various sensors and devices for constructing
ubiquitous computing environments for self-adaptive
applications. Furthermore it is expensive to construct fully the
environment. In addition, before installing in the real system,
we need home simulation to test and verify. Also, the smart
home simulator is an ideal place to apply various context
awareness approaches such as rule based, ontology based, or
case based reasoning. Therefore, prior to the development of
self-adaptive applications, it is necessary to demonstrate that it
is possible to obtain valid context information from virtual
sensors instead of physical sensors.
In this paper, we propose a context aware simulation
system called Interactive SmartHome Simulator aka ISS. By
using ISS, we automatically collect the context information
from a smart home and validate the reactions in ways that fit in
with the environment. This is the main design goal of the
context aware system. As a result, we can improve the
productivity and quality of a smart home realization. This paper
is organized as follows: Section 2 shows ISS infrastructure.
Section 3 described the implementation and how it works via
presenting a case study. Then, our achievements and the
integration of web server into ISS are given in Sections 4 and
Section 5, respectively. Section 6 presents a brief survey of
limitation and problems of related works. In Section 7, we
discuss the comparison between our ISS and other simulators.
Section 8 sums up and draws a conclusion.
2. The proposed system overview
The objective of our proposed simulator is to provide the
interactive actions in smart home environment and attempt to
solve the listed problems. Figure 1 shows the mutual effects
among important components in general.
Context Retriever: requests and receives sensed
information from virtual sensors. There are many kind
of sensors in reality can be listed as light, temperature,
humidity, location, person, etc.
Reasoning: queries and concludes the appropriate
actions to the current context.
Home Appliance: simulates the home devices like TV,
air conditioner, bed and so on. The change of home
appliance’s status affects the home environment as
well.
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Figure 2. Environmental factors in smart home simulator
Home Server: controls the virtual home appliances
such as TV, Air conditioner, gate, curtain, electric-
based devices like neon light, fan, etc.
Home Environment: simulates the real environment.
Like the real home, home simulator is the container
environment consists of smaller environments like
living room, bathroom, dining room, etc. Extrinsic
factors influence the environment. Exchange of
message among extrinsic factors and the environment.
Weather: generates the surrounded weather which also
affects the environment in smart home.
People: models the home’s occupants who have their
own preferences and habits.
Figure 1. The components of proposed framework for smart home
simulator
Those components have relationships to the others.
Reasoning part receives data from context retriever as well as
creates the event and sends to Home Server. Meanwhile, Home
Server changes the status of home appliances so that it affects
the home environment and Home Environment causes the
sensor data to be changed. The home users and weather factor
generate the effects to home environment which also play the
important roles in reasoning process.
3. Implementation
In this section, first of all, we present our implementation
for important components. Then, we introduce some techniques
used to make the application more effective.
3.1 ISS components realization
Context awareness is a vital component in smart home.
According to Chen and Kotz [5], context-aware services can be
classified as passive or active. Active context-aware services
are those that change their content autonomously on the basis
of sensor data whereas passive context-aware services only
present the updated context to the users and let them specify
how the application should change. Likewise, many researches
assume smart home processes one room which means smart
home simulator is equal to smart room simulator. However,
virtual smart home space consists of many child environments.
For example, the internal smart home space includes living
room, bedroom, bathroom, kitchen, etc. So, the mission of the
simulator is to implement all of those. . Figure 2 illustrates the
structure of context information in which the data are divided in
sub-environment.
The simulator also makes the surrounded environment
which takes account into the weather element. In fact, we tend
to get real data by using Web Service connecting to Yahoo
Weather services in order to get the surrounded weather of our
area, with the Kwangju region code. But it certainly takes such
a long time to wait until the next change of the weather.
Therefore, we provide the ability to stimulate the weather to the
developers so that they can change the status of the weather
belongs to four types of typical sorts of weather in Korea: rain,
snow, hot, cloudy. From the weather element, the sensed
internal home context information including temperature,
humidity, light can be retrieved. When the weather status is
updated, it causes the update of the internal house environment
information
In order to express the touch and feel in smart home
simulator, we consider the implementation of user with user
appearance, user movement, user behavior, home appliance
element: Placement, Status, and environment as well. The
Factor component is implemented as the basic atom which is
derived by Person, Home Appliance, and Environment factor.
Virtual Space possesses the list of factors in aggregation
relationship. Aggregation differs from ordinary composition in
that it does not imply ownership. In composition, when the
owning object is destroyed, so are the contained objects,
whereas, this is not necessarily true in aggregation. For
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Figure 3. The relationship of classes in smart home simulator
implementation
example, a virtual space consists of many child virtual spaces
such as bedroom, living room, etc. And each virtual space owns
corresponding person, home appliance and environment factor.
If the child virtual space closes, its own factors will continue to
exist by moved to the new child virtual space. Therefore, a
virtual space can be seen as an aggregation of factors.
Additionally, the most important part, the context reasoning
part uses rules and case based reasoning. The relationship of
those elements is illustrated in Figure 3.
3.2 The using techniques
We utilized .NET and IDE Sharp Develop [6] which are
open source softwares and free to access. SharpDevelop is an
Integrated Development Environment (IDE) for .NET
Framework applications. It supports the development of
applications written in C#, Visual Basic.NET or F# language. It
is open source and written in C#. Sharp Develop provides all of
the features required from a modern Windows IDE, such as
code completion, project templates, an integrated debugger and
a forms designer. Moreover, to make the effect such as the
action such as entering or leaving smart home, we use thread
and synchronization techniques. Some remarkable techniques
can be listed as using socket and message communication,
building Sensor simulator, user interface, and integrating
Reasoning part. Those mentioned techniques make the
simulation more vivid and lively.
4. Context-Aware component integration into ISS
In our approach, we use Web Server as the main method to
integrate context-aware into ISS. The context-base server waits
for a request from an application and authenticates the
application with an ID and password. The first step of an
application is to contact the Context Register of infrastructure.
To achieve this, we have implemented a simple Context Server
Discovery Protocol.
The CSDP is a protocol that allows clients to dynamically
obtain IP address and port number of context register. It
operates similarly to Dynamic Host Configuration Protocol [7].
Application as a client broadcasts a discovery packet and
context register as a CRDP server responds by sending an offer
packet includes IP address and port number of Context
Register. The procedure of the communication between the
sender (ISS) and the receiver (Context-Aware Server) is shown
in Figure 4.
Sender Receiver
CSDP request
CSDP response
Authentication response
Response reasoning results
Authentication request
Send environment metadata
1
2
3
4
5
6
Figure 4. Operations between Context-Aware Server and Smart Home
Application
The most visible goal of this approach is that we can
facilitate the change of ways to reason. For example, while the
input and output format are unchanged, the reasoning part just
follows the algorithm programmed such as case based, rule
based or ontology reasoning. To realize message
communication, in the .NET Framework, we can create
connection-oriented communications with remote hosts across
a network. To create a connection-oriented socket, separate
sequences of functions must be used for server programs and
client programs.
5. Achievements
In this section, we present our achieving results and
evaluation. After the scenario introduction, we show some
achievement results from this.
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5.1 Case study
In this paper, we realized the prototype case study as the
following:
“Currently, this is the autumn season, the most beautiful
season in Korea. When Mr. Lee arrives home and after
certification, he enters home and the light goes on. Also, the air
conditioner is turned on and switched to cooling mode. After
changing his clothes, he sits on the sofa. At this time, the
context manager, detecting his sitting on the sofa, turns on the
TV to a channel based on his favorite. When he goes out to do
something, every appliance at home will be turned off”
We chose TV and sofa for an example of the application.
This case study seems to be very simple but it is practically
more complicated in the real situation.
5.2 The achievements
To prove that ISS can simulate the usual cases in the real
home, we process the above case study on our simulator. Figure
5 shows the results when operating the case study. In Figure 5a,
Mr. Lee is not at home, and everything inside is off. At this
moment, the current weather is normal. When Mr. Lee
authenticates and enters home, the light is turned on and the AC
is also switched to cooling mode, the temperature decreases
from 29 to 26 degree Celsius. The simulator updates the
information of temperature. When the location sensor detects
that Mr. Lee sits on Sofa position, the smart home simulator
supposes Mr. Lee uses the sofa and the TV has been set to be
turned on and switched to his favorite channel as shown in
Figure 5b. The communication between ISS and Context-
Aware Server is illustrated in Figure 6. The Context-Aware
Server recorded the appearance of Mr. Lee and his action
“sitting on the sofa”. After doing the simple reasoning, TV and
air conditioner in living room are turned on. All of the
operations of ISS have been done in real-time. Eventually, the
operation of ISS satisfied the above mentioned case study.
(a)
(b)
Figure 5. The result of before and after states of ISS when operating the case study
Mr. Lee is outside
Mr. Lee is in the
living room
Air conditioner is
turned on
TV is on
Mr. Lee uses the
sofa
TV is off
Air conditioner is
turned off
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6. Related works
A smart home needs smart electronic appliances but it
does not mean they are smart homes itself though they provide
intelligent services. To fit each user’s request for their suitable
services, it is necessary to integrated management system.
There have been lots of works on this research area
including the big corporations and research groups. As a
result, various ubiquitous computing simulators such as the
Ubiquitous Wireless Infrastructure Simulation Environment
(Ubiwise) and TATUS and Context Aware Simulation Toolkit
(CAST) have been proposed. The Ubiwise Simulator is used
to test computation and communication devices. It has three
dimensional (3D) models that form a physical environment
viewed by users on a desktop computer through two windows
[8]. This simulator focuses on device testing, e.g., in
aggregating device functions and exploring the integration of
handheld devices and Internet service. Thus, this simulator
does not consider an adaptive environment. TATUS is built
using the Half Life game engine. Therefore, it looks like an
assembled simulation game. It constructs a 3D virtual
environment, e.g., a meeting scenario. Using this simulator, a
user commands a virtual character to perform tasks, such as to
sit down. This simulator does not consider device simulation
[9]. CAST is a simulator for the test home domain. This
simulator uses scenario based approach. It has been proposed
as a prototype using Macromedia’s Flash MX 2004 [10].
However, using Flash MX [11, 12] does not support users to
freely control their environment. JoonSeok Park et al.
proposed the design structure for smart home simulator
regardless of environment factor as well as interaction aspect
[13]. From Table 1, the comparison our proposed system with
relevant works is shown.
Table 1. Comparison between proposed ISS and other simulators
Row
No.
Simulator
Display
Real
-
time
Involving
factors
Extraordinary
remarks
1
CASS
Java
app.
Yes
Human,
space
Good design
2
CAST
Flash
No
Human,
space
Using Flash
3
Ubiwise
3D
No
Human,
space,
sensor
Simulating 3D
environment
4
TATUS
3D
No
Human,
space
Using game
engine
5
ISS
Interact-
ive Form
Yes
Human,
space,
sensor,
weather,
home
appliances
Representing
highly the
interaction,
support Web
Server integration
7. Discussion
As mentioned in the related works, there are many
shortcomings of the state-of-the-art research and current home
simulation approaches still have limitations. Generally, most
of the current simulators were not built as the real-time
application, and not taken account the real-time aspect in
building the system. The related works also have no
environment effects and no user interactions in the
implementation. Therefore, our approach considers the
following important principle of the environment: interaction,
placement, retrieve environmental information.
Obviously, making the simulator is always easier than
doing the same thing in the real environment. However,
working with simulator help us to anticipate what will
confront in the near future. Many parts don’t look easy to
realize as they are in the simulator. For example, in the user
location sensor, implemented this part in the real environment
have a big trouble, in order to recognize the people, we use
RFID tag and RFID reader [14], to recognize the location, we
use ZigBee based on RSSI [15]. However, to know “who is
there” is still a very interesting topic to ubiquitous computing
research. Also, there are so many other troubles to face when
working in the real environment.
In addition, the implementation of Smart Home Simulator
which is developed in Java and C# .NET also has another
discussion. In common, everyone implies these system boards
are so small of weak to install the cumbersome software when
mentioning about the middleware for smart home. However,
the development of modern board causes the configuration is
eligible to set up the latest version of various operating
systems such as Windows, Linux, Mac OS. Thus, the
simulator can be realized in the real system for both current
and upcoming system boards. The works in smart home
should be done in the simulation first and then those can be
emigrated to the real environment.
8. Conclusions
In ubiquitous computing environments, new-generation
applications are not small and stand-alone but are complex
system. In this paper we present the Interactive SmartHome
Simulator (ISS) that models the relationship between the
environment and other factors in smart home. This paper also
describes the ISS system architecture and hierarchical rule
structure model for Smart Homes. By using this simulator,
users can customize the environment at ease such as
determining the optimal union sensor and device placement.
For future works, we plan to extend the simulator in order
to handle and process complex context information like profile
information and meta-data. Following the work with the
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simulation, several of context reasoning methods are able to be
tested in the virtual smart home environment.
9. Acknowledgment
The authors would like to thank the BK21 Project of
Korea and the anonymous reviewers for useful comments.
REFERENCES
[1] Mark Weiser, "Ubiquitous Computing", Nikkei Electronics, pp.137-143,
December 1993
[2] M. Weiser, “the Computer for the 21st Century”, American Science,
1991, pp.3-9.
[3] Sei J., "Research Activities on Smart Environment”, The Institute of
electronics engineers of Korea Journal, pp. 1359-1371, December 2001.
[4] Chemishkian, S., “Building smart services for smart home”,Networked
Appliances, p.p 215-224, January 2002
[5] G. Chen and D. Kotz, A Survey of Context-Aware Mobile Computing
Research, Technical Report: TR2000-381, Department of Computer
Science, Darthmouth College, Hanover, NH (2000).
[6] SharpDevelop homepage,
http://www.icsharpcode.net/OpenSource/SD/
[7] Droms, R.: Dynamic Host Configuration Protocol. RFC 2131, IETF
(1997)
[8] John J. B., and Vikram V., “UBIWISE, A Ubiquitous Wireless
Infrastructure Simulation Environment”,
http://www.hpl.hp.com/techreports/2002/HPL-2002-
03.html?jumpid=reg_R1002_USEN
[9] O'Neill, E.,Klepal, M.,Lewis, D. O'Donnell, T.,O'Sullivan, D., and
Pesch, D., “A testbed for evaluating human interaction with ubiquitous
computing environments”, Testbeds and Research Infrastructures for the
Development of Networks and Communities Conference, pp. 60-69,
Feb. 2005.
[10] InSu K., HeeMan P., BongNam N., YoungLok L.,SeungYong L., and
HyungHyo L., “Design and Implementation of Context Awareness
Simulation Toolkit for Context learning” , IEEE International
Conference on Sensor Networks, Ubiquitous, and Trustworthy
Computing, vol. 2, pp. 96-103, 2006.
[11] J. Kaye, D. Castillo, “FlashTM MX for Interactive Simulation”,
ISBN:14-0181-291-0, THOMSON, 2005
[12] Craig Swann, Gregg Caines, “XML in FlashTM”,ISBN:0-672-32315-X,
QUE Publishing, 2002
[13] JoonSeok Park, Mikyeong Moon, Seongjin Hwang, Keunhyuk Yeom,
“CASS: A Context-Aware Simulation System for Smart Home”, in Proc.
of Fifth International Conference on Software Engineering Research,
Management and Applications, 2007
[14] Roy Want, "An Introduction to RFID Technology", PERVASIVE
computing Journal, 2006
[15] G. Ferrari, P. Medagliani, S. Di Piazza, M. Martalò, "Wireless sensor
networks: performance analysis in indoor scenarios", EURASIP Journal
on Wireless Communications and Networking, Volume 2007 Issue 1,
January 2007
Figure 6. The screenshot of the communication between ISS and Context-Aware Server
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