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Communication Channels are physical medium through which data is transmitted from one device to another like cable, optical fibre, etc.

Communication Channel connect one device with another for data transmission.

There are different types of communication channels with organisation uses depending upon their requirement.

The type of communication channel selected by organisation depends upon the reliability, security, cost, and most important characteristics Bandwidth of channel required by organisations.

Bandwidth:

§  Bandwidth is measurement of channel data carrying capacity that more the bandwidth of channel is there more will be its data carrying capacity that more the bandwidth of channel is there more will be its data carrying capacity.

§  Bandwidth is measured in kbps, mbps and gbps.

§  The communication channels are normally provided by telecom organisation as a service known as communication services.

§  Followings are type of Communication Services available in market.

Narrowband Services:

§  Narrowband provides slow speed communication channels for data transmission.

§  Usually, this service is used where data volume is relatively low; the transmission rates usually range approx. from 45 to 300 bits per second.

§  Examples of this technique are the telephone companies’ typewriters exchange service(TWX) and Telex service.

Voice Band Services:

§  Voice Band Services use ordinary telephone lines to send data messages.

§  Transmission rates vary from 300 to 4,800 bits per second, and higher.

§  Telephone line is one of the most popular types of communication channel used for data communication.

Wideband Services:

§  Wideband Services provide the highest speed communication channels.

§  Wideband Services provide data transmission rates from several thousands to several million bits per second.

§  These services are mainly used by high-volume data communication users.

§  Such services generally use coaxial cable, microwave communication space satellites or optical fiber to rapidly transmit data from any part of the world.

§  Communication Services may be either leased or dialled up types.

§  A leased communication channel provides a user the exclusive use of the channel; and this is used when there is round the clock data transmission needs.

§  The dial up service requires a person to dial up the ISP system number for internet connection, for data communication; this alternative is appropriate when there is periodic need for data transmission.