TECH EDUCATION | DATA COMMUNICATION AND NETWORKS Series 3 by @anyiglobal

Good day everyone!

I come with the 3rd series of the above topic. In the previous series, we discussed about LAN, WAN, and so on... Without wasting much of our time, we will discuss about Hardware for data communications. Get yourself ready let's ride on.

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Hardware for Data Communications

All the data communications applications we have talked about in this series require only three hardware elements:

• Central Processor(s)

• Terminals (or microcomputers and Minicomputers) at remote locations

• Communication channels or links

We will now look at communication channels. They fall into three categories or types: hardwired, telephone lines, or alternate channels such as leased lines, microwave, or satellite links. We will now look at each of these media in details.

Hardware Links

When terminals are directly and permanently linked to a central processor by cable, they are said to be hardwired. Three basic hardwired transmission media are twisted pair cable, coaxial cable, and fiber optic cable.

Twisted pair cable

Twisted-pair cable is the typical telephone line and is the most common type of communication channel for small systems. It consists of bundles of pairs of copper wires that are twisted together to give them strength. Twisted of pair copper wires that are twisted together to give them strength. Twisted pair cable is relatively inexpensive and has a low maintenance costs. A major disadvantage of twisted-pair wiring is that it is highly susceptible to electrical interference.

Coaxial cable

A coaxial cable is used in place of standard twisted-pair cables for high quality data transmission. Although more expensive than twisted-pair cable, coaxial cables major advantage is that it is sturdy enough to be laid just as it is. It is laid under the floor or ceiling.

Fibre optic cable

Fibre optic cables are highly reliable communication channels; data can be transmitted at very high speeds with few or no errors. Unlike wire cables, fibre optic cables are not subject to electrical interference.

Using a telephone for Data Communications

The standard telephone system is commonly used for connecting computers over long distances; terminals can be moved virtually anywhere in the country — or even the world — and still have access to a mainframe. Telephone lines has several disadvantages as the medium for data transmission. They are slower and have higher error rates than hardwired cables because they are designed to handle signals suitable for voices, not for digital computer signals.

To send signal computer data over the phone, you need additional interface equipment such as modems and acoustic couplers.

Modulation, Demodulation and Modems

Data in a computer is formatted as digital signals or on-off electronic pulses. Because telephone lines are designed to transmit the human voice, they format data as analog signals — or electronic waves. For communication between computers to take place over a telephone line, the digital signal must be converted to analog signals before it can be transmitted. After it's journey over the telephone lines, the analog signal must then be reconverted back to a digital signal so that it can be used by the receiving Computer. The process of converting digital signal to analog signal is called modulation, while the process of reconverting the analog signal back to digital signal is called demodulation

Modulation and Demodulation
source

Acoustic couplers

An acoustic coupler is a form of modem. When you cannot connect your modem directly to a telephone line, you can use an acoustic coupler. The acoustic coupler sends audio signals through the telephone headset to the modem. It has two cups which the handset of your telephone is placed. The acoustic coupler sends data through the mouthpiece and receives data through the earpiece of the handset. Although this type of modem is not used very often, it is useful for transmitting data from locations with internal phone systems such as hotels.

Conclusion

Hardware for data Communication are really important in data communications and networks. Thanks for staying till the end of this class. Hope you learnt something new today? If any question, please kindly drop it in the comment section below!

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@campusconnectng
@whitestallion
@sergeyk
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@fredquantum