Data Communication
Data communication is the exchange of data between two or more devices (like computers, phones, or sensors) using a transmission medium (such as cables or wireless signals). The goal is to transfer information accurately and efficiently from one point to another.
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| Data Communication System |
Data communication, including transmission and reception, is the transfer of data, transmitted and received over a point-to-point or point-to-multipoint communication channel. Examples of such channels are copper wires, optical fibers, wireless communication using radio spectrum, storage media, and computer buses. The data are represented as an electromagnetic signal, such as an electrical voltage, radio wave, microwave, or infrared signal. Analog transmission is a method of conveying voice, data, image, signal, or video information using a continuous signal that varies in amplitude, phase, or some other property in proportion to that of a variable. The messages are either represented by a sequence of pulses using a line code (baseband transmission) or by a limited set of continuously varying waveforms (passband transmission), using a digital modulation method. The passband modulation and corresponding demodulation are carried out by modem equipment. Digital communications, including digital transmission and digital reception, are the transfer of either a digitized analog signal or a born-digital bitstream. According to the most common definition, both baseband and passband bit-stream components are considered part of a digital signal; an alternative definition considers only the baseband signal as digital, and passband transmission of digital data as a form of digital-to-analog conversion.
Introduction to Data Communication
Data communication refers to transferring data or information between two or more devices using a transmission medium such as cables, radio waves, or optical fibers. This exchange allows devices like computers, smartphones, and servers to share information and resources. The primary goal of data communication is to ensure that data is sent and received accurately, efficiently, and securely. For successful communication, both the sender and receiver must follow a common set of rules known as communication protocols. With the rapid development of technology, data communication has become an essential part of modern life, forming the backbone of the internet, telecommunication systems, and computer networks. It enables everything from sending emails and browsing the web to real-time video conferencing and online gaming.
Mention The Basic Elements Of A Communication System
- Sender- The device that sends the data (e,g, a computer).
- Receiver- The device that receives the data (e.g., a printer).
- Transmission Media- The path the data takes (e.g., fiber optic cable, Wi-Fi).
- Protocol- A set of rules that guide how data is sent and received.
- Message - The data being sent (e.g., text, video, audio).
The 6 basic elements of the data communication system. They are
Information, sender, transmission media, receiver, protocol, feedback
- Broadband and Mobile Communication
The early 21st century witnessed the proliferation of broadband internet connections, offering higher speeds and increased data capacity. This enabled seamless streaming, file sharing, and online collaboration. Mobile communication also advanced rapidly, with the introduction of smartphones and wireless networks like 3G, 4G, and eventually 5G, providing ubiquitous access to data services.
- ARPANET and the Birth of the Internet
In the 1960s, the Advanced Research Projects Agency Network (ARPANET) was established by the U.S. Department of Defense, connecting computers at various research institutions. ARPANET laid the foundation for the internet by implementing key protocols like TCP/IP, ensuring reliable data transfer between different networks.
The late 19th century witnessed the birth of the telephone, a device that transformed data communication by allowing voice transmission. Alexander Graham Bell’s invention ushered in a new era of real-time communication, enabling people to converse over long distances. Initially, telephones relied on analog signals carried over copper wires.
What is Synchronous Transmission?
Synchronous transmission is a method of sending large amounts of data. It is widely regarded as an effective and dependable method of data transfer. During synchronous transmission, the clocks of the sender and receiver are unified, and data transmission occurs between the two without an interval. Because the volume of data being transmitted is relatively large, data signals are streamed continuously, accompanied by timing signals. Each character has start and stop bits, which show how they should be combined into data frames. The first part of a data frame contains a set of synchronization characters that notify the receiver that data has been received. For the data to be transmitted correctly, both the sender and the receiver must be synchronized. This is another function performed by the synchronization characters.
Example of Synchronous Transmission
- Transfer of large text files.
- Chatrooms.
- Video conferencing.
- Telephone conversations, (If you’re looking for telephone providers, take a look at this rundown of the best business phone systems in Vancouver).
- Shared clock or timing signal.
What is Asynchronous Transmission?
Asynchronous transmission, sometimes referred to as start/stop transmission, involves sending data to the receiver using the flow control method. Data is synchronized between the sender and the receiver without the use of a clock. Data is transmitted one character or 8 bits at a time. In total, 10 bits are transmitted, with a start bit preceding the character and a stop bit following it. In this way, character-based synchronization is employed. This removes the need for two-way communication. One of the characteristics of asynchronous transmission is that the receiver is largely unaware of when data will arrive. The first bit has passed before the receiver has detected the data and had a chance to respond.
Example of Asynchronous Transmission
Simplex Mode Communication
In simplex transmission mode, the communication between sender and receiver occurs in only one direction. The sender can only send the data, and the receiver can only receive the data. The receiver cannot reply to the sender.
Simplex transmission can be thought of as a one-way road in which the traffic travels only in one direction—no vehicle coming from the opposite direction is allowed to drive through.
To take a keyboard/monitor relationship as an example, the keyboard can only send the input to the monitor, and the monitor can only receive the input and display it on the screen.
The monitor cannot reply or send any feedback to the keyboard.
Half Duplex Mode Communication
The communication between sender and receiver occurs in both directions in half-duplex transmission, but only one at a time. The sender and receiver can both send and receive the information, but only one is allowed to send at any given time.
Half-duplex is still considered a one-way road, in which a vehicle travelling in the opposite direction of the traffic has to wait till the road is empty before it can pass through. For example, in walkie-talkies, the speakers at both ends can speak, but they have to speak one by one. They cannot speak simultaneously.
Full Duplex Mode Communication
In full-duplex transmission mode, the communication between sender and receiver can occur simultaneously. The sender and receiver can both transmit and receive at the same time. The full-duplex transmission mode is like a two-way road, in which traffic can flow in both directions at the same time. For example, in a telephone conversation, two people communicate, and both are free to speak and listen at the same time.
