2. TIMELINE OF THE DEVELOPMENT OF RADIO AND
TELECOMMUNICATIONS
Optical
Telegraph
(1790’s-1800’s)
Electrical
Telegraph
(1830’s-1840’s)
Image
Telegraph
(1850’s)
Telephone
(1870’s-1880’s)
Teleprinter
(1900’s)
Land mobile
(1910’s)
Radio relay
(1940’s)
Telefax
(1960’s)
Cellular radio
(1970’s)

3. TIMELINE OF THE DEVELOPMENT OF RADIO AND
TELECOMMUNICATIONS
Videophone
(1975’s)
Electronic
Mail (1990’s)
iPhone
(2005)
iPad (2010)

4. OPTICAL TELEGRAPH
o a system of conveying information by
means of visual signals, using towers
with pivoting shutters, also known as
blades or paddles.
o Information is encoded by the position
of the mechanical elements; it is read
when the shutter is in a fixed position.

5. OPTICAL TELEGRAPH

6. ELECTRICAL TELEGRAPH
o a telegraph that uses electrical
signals, usually conveyed
via telecommunication lines or radio.
o The electromagnetic telegraph is
a device for human-to-
human transmission of coded
text messages.
o The electrical telegraph, or more commonly
just 'telegraph', superseded optical
semaphore telegraph systems

7. ELECTRICAL TELEGRAPH

8. IMAGE TELEGRAPH
o Data was transmitted at about four to six
bits per second in the latter half of the
1800s, which was as fast as a human
hand could tap out Morse code.
o The unit on the right is the telegraph key.
A metal bar on the receiver simply
banged against another bar when the
current passed through, creating a
clicking sound.

9. IMAGE TELEGRAPH

10. TELEPHONE
o A telephone, or phone, is
a telecommunications device that permits
two or more users to conduct a
conversation when they are not in the same
vicinity of each other to be heard directly.
o First patented in 1876 by Alexander Graham Bell
and further developed by many others, the
telephone was the first device in history that
enabled people to talk directly with each other
across large distances.

11. TELEPHONE

12. TELEPRINTER
o an electromechanical typewriter that can be
used to send and receive typed messages
from point to point and point to multipoint over
various types of communications channels.
o They were adapted to provide a text-based
user interface to early mainframe
computers and minicomputers, sending typed
data to the computer with or without printed
output, and printing the response from the
computer.

13. TELEPRINTER

14. LAND MOBILE
o denotes a wireless communications
system intended for use by terrestrial
users in vehicles (mobiles) or on foot
(portables).
o Such systems are used by emergency first
responder organizations, public works
organizations, or companies with large
vehicle fleets or numerous field staff.

15. LAND MOBILE

16. RADIO RELAY
o Radio stations that cannot communicate
directly due to distance, terrain or other
difficulties sometimes use an
intermediate radio relay station to relay the
signals. Examples include airborne radio
relay, microwave radio relay,
and communications satellite.
o The American Radio Relay League was
founded for this purpose but did not change its
name when this became a less important part
of its work.

17. RADIO RELAY

18. TELEFAX
o the telephonic transmission of scanned printed
material (both text and images), normally to a
telephone number connected to a printer or
other output device.
o The original document is scanned with a fax
machine (or a telecopier), which processes
the contents (text or images) as a single fixed
graphic image, converting it into a bitmap, and
then transmitting it through the telephone
system.

19. TELEFAX

20. CELLULAR RADIO
o A radio communication based on a network
of transmitters each serving a small area
known as a cell: used in personal
communications systems in which the
mobile receiver switches frequencies
automatically as it passes from one cell to
another.

21. CELLULAR RADIO

22. VIDEOPHONE
o a telephone with a video display, capable of
simultaneous video and audio for
communication between people in real-time.
o Videophone service provided the first form
of videotelephony, later to be followed
by videoconferencing, webcams, and
finally high-definition telepresence.

23. VIDEOPHONE

24. ELECTRONIC MAIL
o Electronic mail, most commonly referred to
as email or e-mail since approximately 1993, is a
method of exchanging digital messages from an
author to one or more recipients. Modern email
operates across the Internet or other computer
networks.
o Some early email systems required that the author
and the recipient both be online at the same time, in
common with instant messaging. Today's email
systems are based on a store-and-forward model.
Email servers accept, forward, deliver, and store
messages.

25. ELECTRONIC MAIL

26. IPHONE
o a line of smartphones designed and marketed
by Apple Inc. It runs Apple's iOS mobile operating
system, known as the "iPhone OS" until June 2010,
with the release of iOS 4. The first generation
iPhone was released on June 29, 2007; the most
recent iPhone, the sixth-generation iPhone 5, on
September 21, 2012. The user interface is built
around the device's multi-touch screen, including
a virtual keyboard.

27. IPHONE

28. IPAD
o a line of tablet computers designed and marketed
by Apple Inc., which runs Apple's iOS. The first iPad
was released on April 3, 2010; the most recent iPad
models, the fourth-generation iPad and iPad
Mini, were released on November 2, 2012. The
user interface is built around the device's multi-
touch screen, including a virtual keyboard.

29. IPAD