Home > Data Communications > Data Communication Channels

Data Communication Channels

1. Analog Channel and Digital channel
2. Baud and baud rate
3. Channel capacity of bandwidth

Analog channel and Digital Channel:

By communication channel we mean a medium through which electrical signals can be transmitted. Signals transmitted may be classified as either analog or digital signal.
An analog channel transmits continuously varying signal such as sine waves.

A digital channel on the other hand, transmits binary digits represented by voltage pulses.

Baud and baud rate:

The capacity of a digital channel is measured by the number of bits it can carry per second and is expressed as bps. Or baud rate. For eg : if 1200 bits can be transmitted per second than the channel is said to be 1200 bps. Channel.

Whereas Baud refers to a measure of number of changes per second. A b baud line does not necessary transmit b bits second, since each signal might convey several bits. If the voltages 0,1,2,3,4,5,6 & 7 were used, each signal value could used to convey three bits, so the bit rate would be three times the baud rate.

Channel capacity or bandwidth:

The capacity of an analog channel is specified by its bandwidth. The bandwidth of the channel specify the range of frequencies that the channels can faithfully transmit. Higher the bandwidth of a channel, larger is its capacity to carry information.

For eg : the bandwidth of a coaxial cables used for intercity trunk telephone calls (STD) is about 300 MHz. Such channels are used to transmit several conversion simultaneously using a carrier modulation scheme.

In order to use the larger bandwidth available in some channels several carriers may be used which modulated message signals translating the messages to different bands in the frequency spectrum before there are transmitted. The signals are recovered at the receiving end by demodulating them with the respective carrier frequencies.

More Information
Pulse Code Modulations
Windows Protocol
Frequency Division Multiplexing
Data Transmission Impairments
Error Correction Methods
Error Detection Methods
Basic Transfer of Data
Simplex, Full & Half Duplex
Asynchronous Data Transmission
Electromagnetic Waves
Fibre Optic
Serial, Parallel & Synchronous Data Transmission
VSAT Communications
Satellite Communication
Transmission Lines
Data Formats
Multimedia Software
Desktop Enhancement
Web Designing Services
Flash Memory

Related Information
Data Recovery UK
RAID Recovery
Mortgages
Project Management
Ediscovery