What is a Computer Network and Communication System?

What is a Computer Network?

A network refers to a collection of nodes. These nodes can be any device such as a computer, printer, scanner, etc.

Computer Network is a collection of computers connected together by a communication medium. The connection medium can be any medium including copper wire, microwaves, fiber optics, etc.

These networks are combined to form larger networks and the internet is the best example of it.

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Uses of Computer Networks –

1. BUISNESS APPLICATIONS

• Sharing of devices such as printers, scanners,s or information among the employees
• The client-server model is widely used.
• Telephone calls between the employees are done with the help of technology named Voice over IP (VoIP)
• Desktop sharing is done among the employees
• E-commerce is doing trade online. This is quite common in modern days.

2. HOME APPLICATIONS

• Person-to person communication
• E-commerce
• Gaming

3. MOBILE USERS

• Text Messaging
• Gaming
• GPS

4. Social Issues

Apart from the pros of social media, there comes cons. People share their views on social, political, and ethical topics for getting views and likes. These are not limited to text. But, often they are shared in the form of high-resolution images, and videos. These may be offensive to some people and fights arise due to this.

Other than this, content which may lead to problem in someone’s life such as pornography are also shared. Different countries have different laws in their area regarding this.

What is a communication system?

A communication system is a collection of devices, networks, and protocols that enable the transmission and exchange of information between two or more parties. It provides a means for people or machines to share data, ideas, and messages over short or long distances.

Components in a Communication System –

A communication system typically consists of the following components:

1. Sender/Transmitter: The sender is the source of information or message that needs to be transmitted. It converts the message into a suitable format for transmission.
2. Receiver: The receiver is the destination of the transmitted message. It receives the signal and decodes it to retrieve the original message.
3. Medium/Channel: The medium or channel is the physical path or link through which the information is transmitted. It can be wired or wireless, such as cables, optical fibers, or electromagnetic waves.
4. Message: The message is the information to be transmitted. It can be in the form of text, voice, video, or any other form of data.
5. Encoding and Decoding: Encoding is the process of converting the message into a suitable format for transmission, often using modulation techniques. Decoding is the reverse process, where the received signal is converted back into the original message.
6. Modulation and Demodulation: Modulation is the process of modifying a carrier signal with the encoded message, allowing it to be transmitted efficiently over the channel. Demodulation is the reverse process of extracting the original message from the modulated signal.
7. Protocols: Protocols define the rules and standards for communication between devices. They specify how data is formatted, transmitted, received, and interpreted, ensuring compatibility and reliable communication.
8. Noise and Interference: Noise refers to unwanted disturbances that can corrupt the transmitted signal, while interference arises from other sources sharing the same channel. Communication systems employ various techniques, such as error correction codes and signal processing algorithms, to mitigate noise and interference effects.

Examples of communication systems

Examples of communication systems include telecommunication networks (telephone systems, cellular networks, the Internet), radio and television broadcasting systems, satellite communication systems, and computer networks. These systems facilitate the exchange of information between individuals, organizations, and devices, enabling seamless communication and collaboration in various domains.

Effectiveness of a Communication System –

The effectiveness of a Communication System depends upon four criteria –

• Delivery – The data should be delivered to the user it is intended to. Also, the data should be delivered to that user only, not the other users because the data can be useful information too.
• Accuracy – The data should be delivered in the same way as it is sent. Alteration in the data may lead to incorrect data which will not be useful.
• Timeliness – The data sent should be delivered without delay. The significant delay also refers to the sending of data in the same order as it is intended.
• Jitter – This is a variation in the arrival time of different packets. It is a delay in the delivery of audio or video due to which inaccurate results may be produced at the receiver end. For example, packets of the video are sent in a time delay of 10ms. If some of the packets are sent with a time delay of 20ms then the resulting video produced may be incorrect.

DATA FLOW

Data Flow between two devices can be of two types. These are simplex, half duplex, or full duplex.

Simplex -In this case, the data is shared in a one-way manner. One of the devices can only share data and the other device can only receive data. For example, the keyboard is able to send the data and the monitor receives it (it doesn’t include the touch-enabled monitor or screens).

Half-Duplex – In this case, both the devices can act as a sender and receiver. But, not at the same time. If one of the devices is sending the data, the other has to receive it. At the same time, it cannot send the data. Walky-Talkies are an example of it.

Full-Duplex – In this case, both devices can send and receive data simultaneously. The telephone network is the best example of a half-duplex system, where both persons can even speak simultaneously.

Network Criteria –

In the context of computer networks, network criteria refer to the various parameters used to evaluate the performance, efficiency, and effectiveness of a network. Some of the commonly used network criteria include:

1. Speed: This refers to the rate at which data is transmitted and received in the network. It is usually measured in bits per second (bps) or its multiples such as kilobits per second (Kbps), megabits per second (Mbps), or gigabits per second (Gbps).
2. Reliability: This refers to the ability of the network to deliver data accurately and consistently without errors or loss of data. It can be measured in terms of uptime, packet loss rate, error rate, or Mean Time Between Failure (MTBF).
3. Security: This refers to the ability of the network to protect the data transmitted over it from unauthorized access, interception, or modification. It includes measures such as access control, encryption, authentication, and authorization.
4. Scalability: This refers to the ability of the network to accommodate a growing number of users, devices, or applications without degrading performance or quality of service. It can be measured in terms of the maximum number of users or devices that can be supported, or the ability to add new network components as needed.
5. Cost: This refers to the total cost of ownership of the network, including the cost of hardware, software, maintenance, and support. It can also include the cost of downtime, security breaches, or other network-related incidents.

By evaluating a network against these criteria, network administrators and engineers can identify areas for improvement and optimize the network for the specific needs of the organization or users.

So, in this article, we learned about an introduction to computer networks. In further articles, we will learn more about this in detail.