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Transmitting & Receiving
Contents
 Hardware for Transmitting & Receiving:By
Ryan Caulfield
 Software for Transmitting & Receiving: By
Todd John
 Non-Computer Tools for Transmitting &
Receiving: By Ben Sargent
 Social & ethical Issues: By Alex Kencevski
Hardware Used For
Transmitting and
Receiving
Hardware for transmitting and receiving
includes modems and networks as well as the
internal components of the computer.
These include:
• Ports
• Modems
• Networks
• Local Area Networks
Ports
A port is a socket used to connect peripheral
devices. It is usually located at the rear of the
system unit.
 Parallel ports transmit eight bits (one byte) at a time along
eight parallel lines. They are used to connect devices that
send and receive large amounts of data such as printers and
disk drives.
 Serial ports transmit data one bit at a time using only one
communication line. Serial ports are often called COM or
communications ports and are assigned a number such as
COM1 and COM2. Serial ports are used to connect almost
any peripheral device, such as a mouse, keyboard, modem
or plotter.
Modems
A modem is a device that enables data to be transmitted from
one computer to another. The word modem stands for
modulator/demodulator.
Modems may be internal or external.
 Internal modems are a type of expansion card fitted into
an expansion slot inside the system unit. Internal modems
have become popular because they do not occupy desk
space.
 External modems are usually connected to a serial port
(COM1 or COM2), require a power supply and take up
some desk space. They have a set of status lights to
indicate what the modem is doing, and are generally more
expensive than internal modems.
The speed of a modem is measured by the number of bits transmitted per
second or the baud rate. A common transmission speed is 56000 bps, often
abbreviated to 56K.
Networks
When a number of computers (or
terminals) and their peripheral
devices are connected, it is called a
network. The simplest form of a
network is when one computer is
connected directly to another
computer using a cable. However, a
network can also consist of
hundreds of computers connected
together. The devices used to send
data to a computer system or
receive data from a processor are
called terminals. Terminals can be
either dumb, smart or intelligent.
• Dumb terminals do not contain
a processor and usually consist
of a keyboard and monitor.
• Smart terminals can do some
low-level processing such as
text editing.
• Intelligent terminals have both
memory and processing
capabilities. Most personal
computers are classified as
intelligent terminals and are
called workstations on a
network.
Networks are classified according
to the distances they cover and
include local area networks and
wide area networks.
Local Area Networks
Local area networks (LANs) connect computers (or terminals) within
a building or group of buildings on one site. LANs operate in a small
geographical area and the terminals are linked together by cables
(coaxial or fibre optic). They are found in offices, hospitals, schools
and tertiary institutions. LANs often contain a central computer called
the network server. File servers are computers that perform a function
for other computers on the network such as sharing hardware
resources.
• There are three advantages in using a LAN:
• They allow limited hardware resources such as printers, hard disks and
modems to be shared.
• They allow application software (word processing, databases,
spreadsheets and graphics programs) to be shared.
• They improve communication among users on the network by allowing
messages to be sent and received.
Software For
Transmitting & Receiving
Introduction
 All software
applications
transmits and
receives data within
an individual
computer.
 Special
communications
software is used to
send and receive
data over networks
and using modems.
Different software tools for
Transmitting & receiving
There are 4 different methods of
transmitting & Receiving. They are:
Communications Software
Data Compression
Electronic mail (E-mail)
Data Encoding
Communications Software
While hardware forms
the physical interface
between devices in the
transmitting &
receiving process, it is
the software that
controls the interface
& how the process
operates
 Uses protocols to
establish a connection.
 A protocol is a set of
rules that governs the
transfer of data
between computers. It
defines how the
information is
transmitted and how
errors are detected.
Communications Software
 An IP (Internet Protocol)
address is a unique set of
numbers that identifies the
individual computers on
the Internet. IP addresses
are also needed for dialup
connections to the
Internet.
 Two computers must
use the same protocols,
otherwise the data
transfer may be
unsuccessful. There are
a number of different
protocols for networks,
the most popular being
Ethernet and Token
Ring.
Communications Software
QuickTime™ and a
TIFF (Uncompressed) decompressor
are needed to see this picture.
QuickTime™ and a
TIFF (Uncompressed) decompressor
are needed to see this picture.
Data Compression
 Data Compression
reduces the number
of bits required to
represent data. It
compacts the data
so that it takes up
less space on a disk
and requires less
time to download.
 Compressed data
must be
decompressed in
order to extract the
original
information. The
amount a file is
compressed is
measured by the
compression ratio.
Electronic Mail (E-mail)
 E-mail technology has changed very little
since it was invented.
 When you send an e-mail message, the email program running in your computer
contacts the outgoing mail server computer
at your ISP (Internet Service Provider)or
LAN (Local Area Network)
 The mail server looks at the address on the message &, with the help of
some address lists, sends the message to another mail server closer to
its destination. There the process is repeated before it reaches the
server at the destination address, where it is transferred to the incoming
mail server.
 The entire process can take less than a second. When the message
recipient looks at their mailbox, their e-mail software contacts the
incoming mail server at their ISP or LAN. Any messages waiting for
them are sent to their computer & will appear in their ‘inbox’ window
Data Encoding
• Encoding is the process of temporarily
converting data into another form.
• Decoding reverses the process to restore the
data to their original form.
Non-Computers Tool for
Transmitting & Receiving
Social & Ethical Issues
Introduction
 The widespread use of
information
technology has raised
a number of ethical
issues for people. The
following are some of
the issues that relate
specifically to
transmitting and
receiving data:
 The security of data
transferred over the
internet is a greater
problem than data
stored on a single
computer.
 Privacy can be an issue
when receiving
information from the
internet
 Acknowledgment of
sources is necessary when
downloading data. Data
obtained from the internet
is protected by copyright
More Facts
 The internet is
having an impact on
traditional
businesses.
 Some businesses
are being
established that
trade entirely
online.
 Many other
businesses are
establishing web
sites
The End