Communication Channels

• Telephone lines• Coaxial wire• Fiber optic• Microwave• Satellite

TELEPHONE WIRE

• Telephone lines have been the means of transmission status data and voice for years. They consist of some composite cables for copper wires called twisted pairs and culminates in a phone jack.

COAXIAL WIRE

• Cable is a high frequency transmission, replacing the multiple wires of telephone lines by a single solid copper core. It has a capacity 80 times greater than the twisted pair. It is generally used to link networks of computers.

OPTICAL FIBER

• In this case, the data is transmitted as pulses of light along glass tubes. Features: 26.000 transmission capacity is greater than the twisted pair. They are immune to electronic interference. Transmitted at the speed of light.

MICROWAVE• In this network, the medium is a

solid substance but air. Microwaves are radio waves of high frequency traveling in straight lines through the air for that reason alone can transmit at short distances. Example: Sending data between buildings. If distances are greater, antennae must be placed high enough in places.

SATELLITE• Satellite communications

is an artifact, orbiting at about 35.400 km above the earth. Orbit at one point and accurate speed over the planet. They also serve as microwave relay stations. They are capable of transmitting large volumes of data.

Data transmission modes

• 4.1. Bandwidth 4.2. The transmission in series and parallel 4.3. The direction of data flow 4.4. Transmission modes 4.5. Protocols