International Archives of Photogrammetry and Remote Sensing. Vol. XXXII, Part 6. Bandung-lndonesia 1999 
124 
A DISTRIBUTED REMOTE MONITORING SYSTEM USING SATELLITE AS THE TRANSMITTER 
S. Gopinath Rao 
Network Research Group 
School of Computer Sciences, Universiti Sains Malaysia 
11800 Penang, Malaysia 
gopi@network2.cs.usm.my 
ABSTRACT 
The communication, computer and consumer electronics industries are coming together rapidly, creating products and services that 
allow people to establish links and exchange data without using wires. The main such device is Satellite. A communication satellite 
functions as an overhead wireless repeater station that provides microwave communication link between two geographically remote 
sites. Still another use of satellite is for observation. 
One of the main challenging in the network world nowadays is to use it in a certain function such as like tracking oil spills, weather 
pattern and other disaster warning. However most of this areas, network infrastructure is generally very limited. 
The topic of the paper is an application related to disaster warning, which are fire, flood warning using satellite as a transmission 
media. This paper discusses mainly the structure of fully distributed multimedia network architecture to support early disastrous 
event such as fire, flood and also volcano eruption. Satellite has been the main discussion of this paper because satellite transmission 
can cover a wide area over the surface of the earth. Using this tool will help us to monitor a larger area. 
INTRODUCTION 
APAN(Asia Pacific Advanced Networks) is intended to be a 
high-performance network for research and development on 
advanced application and services. This high bandwidth 
network is necessary to transmit data quickly over 2 or more 
sites. 
Real time multimedia applications such as document and video 
conferencing are becoming more important in today’s high 
bandwidth network. Many Corporate and Companies nowadays 
are very eager to use this kind of system. It is mainly because: 
• Multimedia application is becoming more reliable. 
• Multimedia application can be easily seen, heard and 
understood. 
• To minimize costs. 
A distributed system need to be implemented that can support 
this high bandwidth network structure. The focus of this paper 
is to discuss the design and implementation of a distributed 
system using satellite as a main transmission media. 
This distributed system must be very reliable so that it can 
function well without crashing the system. Message passing is 
done using IP. Thus IP packets are used to transmit both control 
and data information to these entities and the output will also be 
IP formatted packets as well. 
This distributed system, which is known, as Remote Monitoring 
System is a Central Multi-point Multimedia streaming system. 
This paper will show us step by step from theory, design stages 
and finally the implementation, testing and commissioning thus 
distributed system. 
The Remote Monitoring System 
It is a system where a remote area is monitored from a distance. 
This system which is also known, as RMS will be added certain 
extra features. Remote Monitoring System is the idea of a 
surveillance system used mainly for security purposes, i.e. in 
banks and in industrial field (production floor). 
It is a Client-Server concept. The basic idea is a computer, 
which is connected to a camera, will act as a server. This server 
will capture images and send it to clients in the sites through the 
Internet. Here the RMS will function as surveillance system for 
forest fire. 
This system would be set up according to diagram 1. A camera 
would be placed on a vantage point, like a tower on a hill top or 
high rise buildings and would be attached to a server. The 
camera will capture images is real time (streaming) and send 
data to a nearby VSAT or satellite dish. The VSAT is used 
because it can send data to satellite that covers a larger area. All 
clients need to establish a connection with the server in order to 
get the real time images. RMS is a point to multipoint 
application, which means clients from several different places, 
can monitor the same remote area. 
IMPLEMENTATION 
This system would mainly consists of 4 parts :- 
a) Server module 
b) Transmission and Communication Module 
c) Client and interface module 
d) Compression and Decompression 
The server module would be dealing with the interaction of the 
camera and the computer, prepares a communication channel to 
establish connection with the clients, send images to the clients 
and monitor the connection status. 
Transmission and Communication module mainly deal with the 
type of communication used to transmit data from server to 
clients. Images transmitted from the server to nearby VSAT. 
VSAT then send the images to satellite, which later broadcast it. 
On the other side, certain VSAT will receive the broadcast 
message from satellite and send it to clients, which is connected 
to the server. The setup for this system is as shown in diagram 
2. The diagram shows how 3 remote sites are connected to the 
APAN network using 56K internet. 
To ensure the system is secured, a TCP/IP connection is made 
with the server for login and password validation. The images 
would be send using UDP packets in compressed style. 
Decompression would take place at the client site. This entire 
process would be done in real time.