Short for modulator-demodulator. A modem is a device or program that enables a computer to transmit data over, for example, telephone or cable lines. Computer information is stored digitally, whereas information transmitted over telephone lines is transmitted in the form of analog waves. A modem convertsbetween these two forms.

2.  Contents
• Introduction .
• How to work with
Modem ?
• Types of Modems .
• Features of Modem .
• Applications of Modem.
• Advantages &
Disadvantages .
• References .
• Conclusion.

3. Introduction to Modem .
◦ A device that
converts analog
signal to digital
(modulation) and
vice versa
(demodulation).
◦ Speed
 1200/2400/9600 bps
 14.4/28.8/33.6 Kbps
 56 Kbps

4. Digital signal
011010001
This modem converts
digital to analog.
The analog signal
(audible)
is sent through
telephone lines.
MODEM
MODEM
Digital signal
011010001
This modem converts
analog to digital.

5. Modem
Wall Jack
Cable
Modem
Ethernet
Cable
Router

6. Home Wireless Network
Wall Jack
Cable
Modem
Ethernet
Cable
Router

7. 
External

Wireless

Cable

Intelligent
External

9. Modem Features
 Speed:
Speed is measured in Bps,Kbps,Mbps,
Gbps.
 Self
Testing:
Modem can test the digital connection on
computer & analog connection on remote
modem .

10.  Auto
Dial/Redial:
Smart modem can dial the phone no & auto
redial if a busy siganl is recevied .
 Auto-Answer:
Modem can automatically answer When
incoming call comes in .
 Voice
Over Data:
A voice conversation to take place while data is
being transmitted .

11. >Businesses in a variety
of different .
>Data transfers .
>Home Wireless Network.
>Machine to Machine
among many others .

12. Advantages

It converts digital signal to analog signal .

Modems not expensive .

Higher transmission speed .

13. Disdvantages

External Modem does not allow you
mobility wit laptop but it does provide
faster connection and less power uptake .

Internal modem allow you mobility to use
wireless Internet at hot spots but
connection is slower and power uptake
greater .

14. • www.modems.org
• www.wikipedia.org
• www.w3school.org

15. Conclusion

Everything in our DSL modem trauma
came to a head yesterday when my wife
tried to call home but couldn’t get the
phone to ring. It would ring briefly on her
end, then go directly to busy or static.