Download УДК 621.391.1 Rudnytska T. H. Teacher Veklich O.O. Topolska A. I.

УДК 621.391.1
Rudnytska T. H.
Teacher
Veklich O.O.
Topolska A. I.
Students of Group 1TK-09
Vinnytsia National Technical University
COMMUNICATION NETWORK CONSTRUCTIONS APPLICATION IN
EDUCATIONAL PROCESS
The humanity is standing at a critical point in the application of technology in
order to empower and extend the global network. Nobody denies the fact that internet
globalization has greatly succeeded. The global network develops simultaneously
with social, commercial, personal, political interconnections. The innovators create
new products and services in order to emphasize the advantages of the networks.
Communication is as important to us as the reliance on water, air, food, shelter.
Different methods that we use to share information are constantly evolving.
Nowadays our communication is being improved and enhanced.
It is unbelievable how quickly the Internet has become an integral part of our
daily routine. The network is transparent to the millions of users due to the complex
of interconnections of media and electronic devices.
The communication begins with information that has to be sent via the media
from one individual device to another. The basic communication structure consists of
message source, message destination and channel.
In reality some additional components are used. They are encoder, transmitter,
receiver and decoder.
The end devices included to the network may play the role of client, server or
both client and server. They are computers, network printers, VoIP phones, security
cameras and mobile handled devices. These devices perform the interface between
human network and communication network.
Intermediary devices connect the individual hosts to the network. Network
access devices (hubs, switches, wireless access points), internetworking devices
(routers), communication server and modems, security devices (firewalls) are related
to intermediary devices.
Network media are a special channel over which a message travels. There are
some kinds of media: copper, fiber optics, wireless. The criteria according to which
the media may be chosen are the size of the area covered, the number of users
connected, the number of types of services available.
Networks types are Local Area Network (LAN), Wide Area Network (WAN),
Metropolitan Area Network (MAN) and Personal Area Network (PAN). The
difference is that LAN is used for separate building or company. WAN makes the
interconnection among other LANs.
There are special predetermined rules that are called protocols. The protocol
suite is a group of inter-related protocols. All protocols are implemented in software
and hardware loaded on each host. The protocols are represented as layered
hierarchy.
Knowing the network construction a new question about its work appears. The
typed message is converted into the binary code and sent to interface card. The
interface card transports the information represented in signal form to the switch in
the same network. When the message gets router interface it is sent to the other
network. In the dignified network the message will be transported in the same way.
One of the perspective communication channels is the satellite communication
which allows broad access to the information throughout the world at any time.
In satellite communication signal transferring between the sender and receiver
is done with the help of satellite. In this process the signal which is basically a beam
of modulated microwaves is sent towards the satellite. Then the satellite amplifies the
signal and sends it back to the receiver’s antenna present on the earth’s surface. So,
all the signal transferring occurs in space.
Two types of satellites which are commonly used in satellite communication
are active and passive satellites. Passive satellites are just plastic spheres with metal
coating. They reflect the coming microwave signals coming from one part of the
earth to other part.
In active satellites an antenna system, transmitter, power supply and a receiver
are used. These satellites are also called transponders. The signal modulated on the
earth is transmitted to the transponder where this signal is amplified and stored in
satellite’s memory. Then signal is transmitted back to earth when earth properly faces
the satellite. Some active satellites also have programming and recording features.
Satellites come in many shapes and sizes and have many uses. The first
artificial satellite, called Sputnik, was launched by the Soviet Union in 1957 and was
the size of a basketball. Its purpose was simply to transmit a Morse code signal
repeatedly. In contrast, modern satellites can receive and transmit hundreds of signals
at the same time, from simple digital data to complex television programs. They are
used for many purposes such as television broadcasting, amateur radio
communications, Internet communications, weather forecasting and Global
Positioning Systems (GPS).
Communication satellites act as relay stations in space. One could imagine
them as very long, invisible poles that relay high frequency radio waves. They are
used to bounce messages from one part of the world to another. The messages can be
telephone calls, TV pictures or Internet connections. Certain communications
satellites are, for example, used for broadcasting: they send radio and TV signals to
homes. Nowadays, there are more than 100 such satellites orbiting Earth, transmitting
thousands of different TV (and radio) programs all over the world.
Satellite Internet access is Internet access provided through satellites. Latest
satellites can achieve speeds up to 18 Mbps. Satellite Internet generally relies on
three primary components: a satellite in geostationary orbit, a number of ground
stations known as gateways that relay the Internet signal to and from the satellite via
microwaves, and a VSAT (Very-small-aperture terminal) dish antenna with
transceiver, located at the user end. Other components of a satellite Internet system
include a modem that translates the signal from and back to a computer and a
centralized Network operations center (NOC) for monitoring the entire system.
One of the most important network applications is E-learning. In this way
students may get the same diplomas as obtained in universities. Information is
represented in the form of video, audio and other entertaining forms. E-learning gives
the students a great opportunity to make video conferences with teachers. The lessons
may be organized at any place and at any time. Thus such kind of education has many
advantages.
People should be aware that networks play the vital role in current
communication. The humanity may only follow this constant process of
communication development. Thus communication network contributes to the
efficiency of the teaching process in all higher educational establishments.
Література
1. «CCENT/CCNA ICND1 640-822 Official Exam Certification Guide» by
Wendell Odom, 3rd Edition, DVD-ROM, 800 pages, ISBN 978-1-58720-425-8, 2012
2. «Computer Networks: Principles, Technologies and Protocols for Network
Design» by Natalia Olifer, Victor Olifer, 1000 pages, ISBN 978-0-470-06407-8,
September 2007, ©2005
3. Basics of satellite communications — Режим доступу до журн.:
http://www.jisc.ac.uk/whatwedo/themes/network/sat/report3.aspx
4. What is Satellite Communication? — Режим доступу до журн.:
http://www.thebigger.com/physics/principles-of-communication/what-is-satellitecommunication/