6. Data Communications over Standard
Telephone Lines - Modems
Most telephone lines are analog, not digital.
modem converts it from analog format to
digital format.
7. `
The analog signal
(audible)
is sent through
telephone lines.
011010001 MODEM MODEM 011010001
Digital signal Digital signal
This modem converts This modem converts
digital to analog. analog to digital.
9. Using Digital Data Connections
Dedicate to transmitting data in digital
format.
Transmit data at much higher speeds than
standard analog phone lines.
11. Broadband Connections
transmit data faster than is possible through
a standard dial up connection using a
modem.
The most commonly used digital telephone
services are:
ISDN,T1 and T3
DSL
Cable Modems
ATM
12. Wireless communication
Use RF or IR to transmit data between
devices on LAN.
Wireless signals are electromagnetic waves
that can travel through a vacuum of outer
space.
14. Local Area Networks
(LANs)
Connected by a cable, infrared link, or small
transmitters.
Transmits data by breaking it into small
pieces.
Every LAN uses a protocol.
22. Conclusion
In this presentation we
Explain how computer data travels over
telephone lines.
Explain a modem’s function.
Differentiate four types of digital data
connections.
Describe how wireless networks functions.