A DISTRIBUTED MONITORING SYSTEM UTILIZING
CELLULAR PHONE AS GUI
Web-based Application featuring Java technologies
Yoshiro Imai, DaisukeYamane, Shin'ichi Masuda, Takaaki Izumo, Hitoshi Inomo, Wataru Shiraki
Faculty of Engineering, Kagawa University 2217-20 Hayashi-cho Takamatsu city 761-0396 JAPAN
Osamu Sadayuki
Sharp Business Computer Software Inc.2-13-1 Happonmatsu Higashihiroshima city 739-0142 JAPAN
Keywords: Remote monitoring and controlling, Java Programming, Cellular phones
Abstract: We have designed and implemented a distributed monitoring system. An integrated server of the system is
designed to play an intensive role to instruct its subsystems by means of network connectivity. Its
subsystems will be organized with, for example, network camera, remote sensors, remote switches and
remote-control devices. They can cooperatively work together, obtain out view and internal state of target
system, and transfer suitable control signals for that system in order to monitor efficiently. Remote
monitoring and remote control are useful for improving system reliability, maintenance and some kinds of
security. In order to realize such monitoring and control, Web service with Java technology is available for
constructing a distributed monitoring system efficiently. Java programming language is much useful for us
to describe smart GUI, system configuration, and network-oriented applications in a short period. Mobile
computing devices, especially, wireless portable PC's and/or cellular phones are useful for client users to
communicate with monitoring and database server at any place as well as at any time.
1 INTRODUCTION
A distributed monitoring system is developed to
realize remote monitoring and control services for
system reliability and maintenance. An integrated
server is designed to be in the center of our
distributed monitoring system and can play a special
role to obtain data from distributed sensors and
network cameras, cumulate several data as database,
extract/select suitable data according to request of
data retrieval from clients, and deliver such data into
them.
Our server can provide other facilities to do
remote control service from clients to scattered
control points partially by means of electric power
lines and to send urgent messages from server to
cellular phones as well as mobile PC's. A prototype
of server is implemented on a Linux machine and its
software is written in only Java programming
language. Software is divided into some modules,
which are designed in the way of server-client
computing model. Modules for server are written as
stand-alone applications of Java, while others for
clients are basically implemented as Java applets
which are constituted for different kinds of clients,
transferred from server to each type of client through
HTTP connectivity, and executed on its browser
and/or performed by Java virtual machine.
This paper describes general view of our
distributed monitoring system including integrated
server, its detail services of remote monitoring and
remote controlling, and case study for distance
experiment prototype.
2 DESIGN OF SYSTEM
Design of system and its performance are to be
summarized as follows:
1) Images are taken by network camera, transferred
to an integrated server, processed to be resized
suitably for each client’s display size, stored as
203
Imai Y., Yamane D., Masuda S., Izumo T., Inomo H., Shiraki W. and Sadayuki O. (2004).
A DISTRIBUTED MONITORING SYSTEM UTILIZING CELLULAR PHONE AS GUI - Web-based Application featuring Java technologies.
In Proceedings of the First International Conference on E-Business and Telecommunication Networks, pages 203-208
DOI: 10.5220/0001392802030208
Copyright
c
 SciTePress

image database, and retrieved/obtained by remote
clients.
2) Remote control services are performed by the
following procedures; a request from client arrives
to the server, it is deciphered to generate control
signal for its according remote control point, its
signal is delivered from server to a special-purpose
microcomputer-based device, and then hardware
logic connected with such a device is switched on or
off.
3) Our remote monitoring system provides current
information of state data and/or camera image about
a noticing target such as factory, office or home,
which is separated away from client.
4) Though the above monitoring facilities, users of
our system can investigate how their targets work
correctly in order to keep their targets under
observation.
5) If some troubles happen, our system can send
urgent messages to the pre-registered clients with
wireless communicating service, and then shut the
electric power off automatically by means of its
remote control facility, if necessary.
3 SYSTEM CONFIGURATION
Figure 1 shows an overview of distributed
monitoring system, which includes some network
cameras, a specific control server named Open
PLANET server, and "Integrated Server". And
moreover system contains some kinds of client
machines, which are denoted as "Note PC" and
"Cellular Phone" illustrated in the above figure.
These servers and client machines are
interconnected by means of the internet and partially
private network.
3.1 Overview of Prototype
Our integrated server can periodically obtain several
kinds of images from network cameras, which are
located in LAN, by means of Web service, store
them in its internal buffer as database and transfer
them according the request of the specific clients of
global network. Our server can also provide some
remote control services for electrical devices in the
internal network in response to the message from
global client. Utilization of Web service and Java
Applet can facilitate some useful GUI mechanism
for users to handle our monitoring system. Overview
of service from integrated server is summarized as
follows:
1) User of client, at first, accesses the home page of
integrated server with web browser.
2) Our Java applet stored in our server is
downloaded into the web browser of client and
begins to work in it.
3) That applet allows communications between user
of client and integrated server.
4) Images are transferred from our server into client
and are displayed on the browser, namely, some
users can recognize state view of targets on their
cellular phones.
5) User's request of control may be performed for
specific electrical device on the internals.
6) An emergency message is carried into certain
users by means of e-mail system and/or cellular
(mobile) phone service, so that pre-registered users
can receive the message on ones cellular phone
Appliances
Network
Camera
OpenPLANET
Integrated Server
Server
Client NotePC
Cellular
Phone
Figure 1: An Overview of Distributed Monitoring System
3.2 Image Transmission Service
In order to realize remote monitoring, it is
completely necessary to obtain several kinds of
images. Although animated (moving) pictures would
be much more effective to piece out the situation
than stationary ones, our system can only deal with
continuously stationary pictures still now. Integrated
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Server requires network camera to transmit JPEG
images at a sampling rate, receives such an image,
reduces a size of image and accumulates a series of
them in the storage. Server also prepares Java Applet
on the homepage in side of it for Web service,
begins to run the process of http daemon (Apache),
waits for clients' access from global network and
then delivers such an Applet to the target client.
Figure 2 shows a scheme of our remote monitoring
procedure.
Figure 2: A Scheme of Remote Monitoring Procedure
At the side of client, Java Applet downloaded
form our server provides a GUI which communicate
server to requests transmitting JPEG image by
means of HTTP connection and display received
JPEG data on the browser in the mode of stationary
image or continuously alternating images like as
slide show. In the case of later mode, the applet
obtains JPEG data from server in advance, stores
and preload in the double-buffering style, and realize
quasi-moving picture on the display of PC's browser.
JPEG data from the server can be also seen on the
LCD of cellular phone. Detail will be described
later.
3.3 Remote Control Service
Remote control service seems to be essential for
supplementing remote monitoring service and
enlarging it into wide application. Various control
mechanisms were proposed and this time we
employs remote power switching facilities as remote
control, which is based upon the Open PLANET
technology and has been developed by Shikoku
Electric Power Company Ltd. It has some excellent
characteristics, one of which is to transmit digital
information from node to node through the electric
power lines.
The Power Consent Adaptor (PCA) is the
special-purpose power outlet based upon the Open
PLANET technology, which can turn on or off
electric power according to control signal from
remote controller via electric line. The Open
PLANET server provides remote control facilities to
do power switching by means of transmitting control
signal for digital information into the PCA.
Our Integrated Server has a connection with such
an Open PLANET server, sends and receives socket-
based messages to/from such a server, and performs
remote control service for electric power switching
through the private networking. Communication
between our server and an Open PLANET server is
carried out based on TCP/IP protocol and software
for their communication is realized with Java
programming. Java codes can be executed not only
on our Integrated Server but also on an Open
PLANET server. And moreover almost software of
our server has been written with Java programming
language.
The merits of employing the Open PLANET
technology are summarized as follows:
1) No additional cabling is necessary to realize
remote power switching, because control signal can
be transmitted via electric power line.
2) No additional remodelling of target device to be
controlled is necessary, because the PCA is
equipped between such a target device and
according conventional power outlet.
Client users can enjoy remote control service
from Integrated Server if they request Java Applet
download from the server to do power switching.
Such an Applet communicates with its server to
allow an Open PLANET server to perform the above
control mechanism. Figure 3 shows a scheme of our
remote controlling procedure.
Figure 3: A Scheme of Remote Controlling Procedure
3.4 Message Mailing Service
Users whose e-mail addresses have been entered in
our Integrated Server can receive e-mails about
some kinds of message from the server, when
monitoring system recognizes whether a situation of
target system needs sending message, for example,
emergency, to client or not.
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Our message mailing service can cover two
following cases:
1) Normal e-mail transmission service, which
includes sending message to such personal
computers connected to LAN, and
2) Mobile e-mail transmission service, which deals
with cellular phone and PHS (Personal Handy phone
System) via global communication network.
In the former case, generally speaking, an e-mail
is one of the most usual message transmission
methods between computer's users of LAN and the
internet. And the message to be sent may contain
description of a special URL, which tells users to get
information about image, control scheme and Java
applet. With such information, clients can access a
suitable resource for them to steer the monitoring
system efficiently.
On the other hand, clients sometimes leave their
seats where they sit down and work with computers.
They will carry cellular phones or PHSs with them,
however, even at such a situation. In the later case,
cellular phones including PHSs provide wide area of
e-mail service to clients, so that message from server
can be delivered to the target clients no matter where
they are. It is very much useful for an emergency
message to be sent to clients when monitoring
system and clients decide to utilize e-mail service of
cellular phones and PHSs. Figure 4 shows a scheme
of our message mailing service.
Figure 4: A Scheme of Message Mailing Service
3.5 JPEG Image on Cellular Phone
With Java Applet, clients can browse monitoring
quasi-moving image obtained from Network Camera
on their browser of PC through Integrated Server.
But it has seemed to be more effective and more
convenient for clients to browse such images with
their cellular phones, because almost people of
Japan always carry their cellular phones with them.
Some kind of Java technology allows us to
utilize small sizes of Java Applet on specific cellular
phones, and then it can be downloaded from a
certain Web server into cellular phones and perform
a mobile communication based on HTTP connection
between them.
Integrated Server has prepared such a Java
Applet on its homepage, deliver it into clients'
cellular phone according their requests, and
communicate it in order to transmit monitoring
images and allow cellular phones to browse them.
As there are some constraints on the image data size,
which one time cellular phones can accept, for both
of transmission and display of it, then our Server
must reduce data size of JPEG images from network
camera into a suitable size for cellular phones and
accumulate these images in its storage for request of
image delivery from cellular phones.
Figure 5: Monitoring Image on a Cellular Phone
Figure 5 shows a sample view of monitoring
image on a cellular phone, which is delivered from
Integrated Server. Frankly speaking, it is a view of a
display image from CLDC (Connected Limited
Device Configuration of J2ME) -based Java
application emulator for a certain cellular phone. In
order to reduce useless traffic cost between cellular
phone and Integrated Server, client of cellular phone
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must make sure to push the bottom for obtaining the
next image from Integrated Server
4 EVALUATION OF PROTOTYPE
As described in the previous section, our prototype
system of Integrated Server can provide several
kinds of services such as image transmission service,
remote control one, message mailing one and Java
applet delivery one, which facilitates browsing JPEG
image on the LCD of cellular phone. This section
describes the current state and evaluation of our
prototype system.
4.1 The Current System of Prototype
Clients of PC, for example, access the homepage of
prototype of Integrated Server, download Java applet
onto PC's browser and let it perform a series of
applications; simultaneously, displaying a series of
monitored JPEGs as quasi-moving picture on the
browser, providing a control facility for electric
power switching by selecting bottoms (On/Off), and
sending message to the specific e-mail address by
means of internet and cellular phone e-mail services.
With Java applet downloaded from server,
Figure 6(a)
shows a
sample of
quasi-moving
picture on the
up side of
browser,
where the
lump has
turned off at
first.
Figure 6(a) Scene before power is controlled
After pushing the left-hand bottom at the left
side of browser, the request of client is interpreted
by the applet and transmitted to the server through
the internet. It is accepted, processed and converted
into a message packet to an Open PLANET server in
order to switch on the lump. The Open PLANET
server generates digital signal according to the
message packet, directly control the PCA connected
to the lump and make the lump turn on.
When the lump turns on, the picture of it has
been taken by network camera, transferred into
Integrated Server, and accumulated as JPEG images
in its storage. The Java applet downloaded into
client has obtained a series of picture data from
Integrated Server automatically and display the
according JPEG image on the browser, which is
shown in Figure 6(b).
By the way, there are two blank text fields at the
right side of browser view shown in Figure 6. When
an e-mail address and content for mail are described
in these text fields respectively, pushing the bottom
to send at the left hand below the text field can allow
such an e-mail to be transmitted into the according
e-mail address. This e-mail service can be provided
not only for
client with
connection of
wired LAN
and the
internet but
for client
with mobile
device such
as cellular
phone.
Figure 6(b) Scene after power is controlled
4.2 Evaluation of the Current System
At the present of our prototype system, the following
services are available in the distributed monitoring
system;
1) Image Transmission Service:
A series of JPEG image file can be periodically
taken by network camera, transmitted into Integrated
Server, and accumulated with simple image resizing
procedure in the storage of that Server. Request to
obtain the buffered image in the Server causes
transmission of such image into the browser of client
PC, process of Java Applet for downloaded images,
and display images on the browser in the manner of
stationary picture and/or quasi-moving picture.
2) Remote Control Service:
The Open PLANET server can perform remote
control for electrical device through electric power
supply line. Our monitoring system has incorporated
this server into the lower layer of Integrated Server
in the private network, which means that system
permit no direct access into the Open PLANET
server from global network. Integrated Server
communicate to ask the Open PLANET server to
perform the control service according to the request
to control several kinds of electric device and
appliance.
This strategy has a week point that control
service is heavily dependant on the function of Open
PLANET technology as well as a benefit that system
is able to block an illegal access for some kinds of
power control from global network effectively.
3) Message Mailing Service:
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Mailing procedure of our system may cover from
wired e-mail service for LAN and the internet to
wireless (mobile) packet message transmission
based on cellular phone global network. As clients
can select their better media which receives a
message sent from Integrated Server, mailing service
of our system is sufficient for practical usage.
4) Display Image on LCD of Cellular Phone:
This facility is only available in cellular phones
of Japan from the specific carrier, namely NTT
DoCoMo. Although NTT DoCoMo, for example, is
one of the major carrier of Japan, we must do best
efforts for our system to be more applicable in order
to utilize other kind of cellular phones from other
carriers of foreign countries.
Current LCD size of cellular phone seems to be
not suitable to display the image for remote
monitoring. Of course, cellular phone is very much
convenient to be carried with user, so we must
expand the facilities of our system such as zooming
and scrolling for small image and/or large one.
In the very near future, we must develop Java
programs for CLDC+MIDP (Mobile Information
Device Profile) -based cellular phone in addition of
i-mode Java programming application for NTT
DoCoMo.
5 CONCLUDING REMARKS
We have described design and tentative
implementation of a distributed monitoring
prototype system. This prototype has been available
to obtain image from network camera, perform
power switching for electrical device and appliance
and so that it can ensure reliable use of electric
and/or mechanical systems. Our monitoring system
contains some kinds of servers: Integrated Server is
designed to play an intensive role to instruct and
integrate its subsystems and sub-servers by means of
network connectivity.
In our work, Web-based application style and
Java programming are essential keys to allow our
system to be much useful to describe several server
programs, smart GUI's for PC’s and/or mobile
phones, and network-oriented applications
efficiently. Instead of Integrated Server, many
subsystems are organized, for example, network
camera, remote sensors, remote switches and remote
control devices. They can cooperatively work
together to realize distributed monitoring system.
Mobile computing devices, especially, wireless
portable PC's and/or cellular phones are useful for
client users to communicate with monitoring and
database server at any place as well as at any time.
Remote monitoring and remote control are
useful for improving system reliability, maintenance
and some kinds of security. In order to realize such
monitoring and control, is available for constructing
a distributed monitoring system.
ACKNOWLEDGEMENTS
The authors would like to express the special thanks
to Mr. Hisashi Nagano of Institute of Shikoku
Electric Power Company, Mr. Shin-ichi Fujihara
(previously a member of Techo-Create Inc.), Mr.
Kazumasa Miyazaki of NTT DoCoMo Shikoku and
Mr. Yoshio Saito of Vodafone Japan for their
constructive advices to develop the prototype of a
distributed monitoring system. They are also very
thankful to Prof. Kazunori Yamaguchi of University
of Tokyo, Prof. Toshiaki Kitamura of Hiroshima
City University, and Prof. Shinji Tomita of Kyoto
University for their continuous helps and supports
for our studies. They think back with gratitude on
Prof. Masakazu Aoki of Kagawa University and
Prof. Haruo Niimi of Kyoto Sangyo University for
their instruction of Java and effective programming
technologies.
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Elliotte Rusty Harold, "Java Network Program-ming, 2nd
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http://www.openplanet.co.jp/
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http://www.nttdocomo.co.jp/i/java/tool.html
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