Data Communication

Table of Contents

• Key Aspects of Data Communication
• Components of Data Communication System
• Measuring Communication Media Capacity

Data communication is like a conversation between devices, such as computers, phones, and laptops. They share different types of information like text, images, audio, and video. Think of it as a network of connected devices, like in the below Figure, where computers, printers, servers, and switches are linked.

Data Communication between the LAN

In simple terms, data communication is about passing information from one place to another. It happens between two devices using a pathway called a transmission medium. This system involves hardware (like sender and receiver devices) and software (protocols that guide the communication). It's like a well-coordinated dance between devices, making sure the information gets where it needs to go.

 

Key Aspects of Data Communication

For a data communications system to work well, it needs to have these four important features:

1. Delivery: Make sure the data reaches the right place and the correct person. It's like making sure your message gets to the right friend without any mix-ups.
2. Accuracy: The communication system must send the data without making mistakes. Sometimes, during the journey, the data can get mixed up or changed. We want to prevent that to make sure the information is correct when it reaches its destination.
3. Timeliness: When we're dealing with audio or video data, it must reach its destination quickly and without delays. Imagine having a phone call or watching a video in real-time; that's what we call real-time transmission of data.
4. Jitter: Jitter is like the ups and downs in the arrival time of data. We want to avoid uneven jitter because it can mess up the timing of the data being sent. Think of it like trying to play music smoothly without any interruptions.

Components of Data Communication System

When we talk about devices communicating through a network, we think about five important parts.

These are the sender (a device that sends data), receiver (a device that receives data), communication medium (the path for data to travel), message (the information being sent), and protocols (rules for communication). The communication medium is also known as transmission media.

• Sender: This is a device like a computer, phone, watch, or any other gadget that can send data over a network.
• Receiver: This is a device like a computer, printer, phone, or TV that can receive data from the network. In computer talk, we call the sender and receiver "nodes" in a network.
• Message: This is the information or data that needs to go from the sender to the receiver. Messages can be text, numbers, images, audio, videos, or other types of data.
• Communication Media: It's the path the message takes from the sender to the receiver. This can be wired (like cables) or wireless (like satellite links or microwaves). For example, TV cables, telephone cables, Ethernet cables, and satellite links are types of communication media.
• Protocols: These are rules that everyone has to follow to make sure communication works well. You might have heard of protocols like Ethernet and HTTP. They help in making data communication successful and reliable.
   

Measuring Communication Media Capacity

In data communication, the path where information travels is called a channel. The channel's capacity is like its traffic limit—how much data it can handle. We measure this capacity using two things: bandwidth and data transfer rate.

1. Bandwidth:

• Bandwidth is like the road width for data. The wider the road, the more cars (or data) can pass through.
• It's measured in Hertz (Hz), which tells us how much data the channel can handle at once.
• Example: If bandwidth is 1000 Hz, the channel can handle 1000 pieces of data in one go.

 

2. Data Transfer Rate:

• Think of data transfer rate as how fast the data travels on the road.
• It's measured in bits per second (bps), showing how many bits move from one place to another in one second.
• Example: If the data transfer rate is 1 Kbps, it means 1000 bits of data move in one second.
• Units for Data Transfer Rate:
  •    - 1 Kbps = 210 bps = 1024 bps
  •    - 1 Mbps = 220 bps = 1024 Kbps
  •    - 1 Gbps = 230 bps = 1024 Mbps
  •    - 1 Tbps = 240 bps = 1024 Gbps

 

In simple terms, bandwidth is like the road's width, and the data transfer rate is how fast the data travels on that road. The bigger the bandwidth and data transfer rate, the more and faster data can be sent through the channel.