Data Communication

Introduction to Data Communication:

In data transmission, digitally stored information is often referred to as data. The process of sending digital information between two or more sites is known as data communication. Information is defined as knowledge or intellect. The result of sending, receiving, and processing digital information simultaneously is data communication. For data communications to occur, the communicating devices must be a part of a communication system that includes hardware and software or physical devices and programs. The effectiveness of a data communications system is determined by four key factors: delivery, accuracy, timeliness, and jitter.

A Data Communication System has five components:

Message: The information (data) that has to be shared is the message. Information is often presented in written, numerical, pictorial, audio, and video formats.
Sender: The term “sender” refers to the equipment that sends the data. It could be a phone, video camera, workstation, computer, or anything else.
Receiver: The apparatus that gets the message is known as the receiver. It could be a television, computer, workstation, phone, or anything else.
Transmission medium: The physical route a message takes to obtain from source to recipient is known as the transmission medium. Radio waves, coaxial cable, fiber-optic cable, and twisted pair wire are a few types of transmission media.
Protocol: Data connections are governed by a set of rules called protocols. It symbolizes a consensus among the speaking parties.

Standard Organizations for Data Communications:

The alliance of companies, consumers, and governmental entities that make up the standards organizations is responsible for developing, arranging, and maintaining the standards. All manufacturers and users of data communications equipment are expected to abide by these regulations.

The main data communication standards organizations are:

1. International Standard Organization (ISO)

The worldwide body responsible for standardization across many different fields is called ISO. Most of its members are appointed by various international governments to standards committees. It is even in charge of creating models that offer a high degree of system interoperability, increased productivity, lower prices, and enhanced quality. The coordination and endorsement of the various standards bodies’ activities are under the purview of the ISO.

2. International TelecommunicationsUnionTelecommunication Sector (ITU-T)

ITU-T is one of the four surviving departments of the International Telecommunications Union and is headquartered in Geneva, Switzerland. It has created three sets of specifications: the I and Q series for the Integrated Services Digital Network (ISDN) and its extension, Broadband ISDN; the V series for modem interfacing and data transmission over telephone lines; and the X series for data transmission over public digital networks, email, and directory services. ITU-T is the current UN standards agency, with members that include representatives and government officials from numerous nations.

3. IEEE: IEEE means Institute of Electrical and Electronics Engineers, Engineers in electronics, computers, and communications make up the members of IEEE, an international professional association established in the United States. With more than 200,000 members, it is currently the largest professional society in the world. It creates information processing and communication standards to promote theory, innovation, and high-quality products in all electrical engineering-related fields.

4. American National Standards Institute (ANSI)

The United States is represented in voting at the ISO by ANSI which is the official standards organization for the country. A private, nonprofit organization, ANSI consists of companies that make equipment and companies that utilize data processing services and equipment. Members of ANSI come from consumer goods, governmental and regulatory agencies, business associations, and professional societies.

5. Electronics Industry Association (EIA)

The U.S. trade association EIA, is a non-profit, sets and suggests industrial standards. The RS (recommended standard) series of data and communications standards is created through the EIA, among other things by lobbying, raising public awareness, and producing standards.

6. Telecommunications Industry Association (TIA)

TIA is the leading trade group in the communications and information technology industry. It facilitates business development opportunities through standards formation, trade promotion, market expansion, and trade shows. It stands for manufacturers of communications and information technology devices and encourages the convergence of new communications networks.

7. Internet Architecture Board (IAB)

The Advanced Research Projects Agency (ARPA) established the Internet Operations Board (IAB), formerly known as the Internet Activities Board, as a group to examine the operations of ARPANET and expedite the development of technology beneficial to the US military.

I. Oversees the architecture protocols and processes used by the Internet. The Internet Architecture Board (IAB) is a technical advisory organization of the Internet Society.
II. Oversees the procedures to develop Internet standards and acts as a hearing board for grievances about incorrect standardization process implementation.
III. In charge of managing the different Internet-assigned numbers
1V. Represents the interests of the Internet Society in liaisons with other organizations.

V. Provides the Internet Society’s officials and board of trustees with counsel and direction on different topics about the Internet and its technologies.

Internet Engineering Task Force (IETF)

A sizable global community of network operators, vendors, designers, and academics, the Internet Engineering Task Force (IETF) is focused on developing Internet architecture and the seamless functioning of the Internet.

Internet Research Task Force (IRTF)

By forming small, focused research groups that concentrate on Internet protocols, applications, architecture, and technology, the IRTF fosters research that will be important to developing the future Internet.

Data Communication Circuits

A digital communications circuit’s primary function is to create a conduit for transmission and move digital data via electrical circuits from one station, or node,—a site for computers or other digital equipment—to another. Digital computer equipment is connected via data communications circuits, which consist of electronic communications infrastructure and equipment. Data communication users can access communication facilities—physical ways of linking stations—through numerous private data communications systems, public data networks, and public telephone networks (PTNs).

A basic data communications circuit with two stations is depicted in the accompanying diagram. The principal elements consist of:

Source: The data to be transferred is generated by this device, which can be a workstation, personal computer, mainframe computer, etc. The source hardware gives users a way to enter data into the system.

Transmitter: A transmitter transforms and encodes data to produce an electromagnetic signal that may be transferred through a transmission system. A modem is a device that converts a digital bit stream from an associated device, like a personal computer, into an analog signal that is compatible with the phone network.

Transmission medium: – From the sender to the recipient, the encoded signals are transported via the transmission medium. Free-space radio transmission, or all wireless transmission, and physical infrastructure like metallic and optical fiber cables are examples of different types of transmission media.

Receiver: After obtaining the signal from the transmission medium, the receiver converts it into a format, that the intended device can comprehend. A modem, for instance, can take an analog signal from a transmission line or network and transform it into a digital bit stream.

Destination: The destination, which can be any type of digital equipment similar to the source, receives the incoming data from the receiver.

Serial and Parallel Data Transmission:

Digital data can be transmitted using two different methods: serial and parallel transmissions. All the binary data’s bits are sent at once during parallel data transmission. For instance, eight transmission lines are needed to send an 8-bit binary number in parallel from one unit to another. Every bit needs its unique data path. A word is conveyed in its entirety at once. A substantial amount of data can be transferred with this transmission method in a short length of time. The numerous connection cords between the two units are a drawback.

Large binary words require costly and complicated cabling. This is especially valid in cases with a significant gap between the two units. In addition to more cost, long multiwire cables need specialized interfacing to reduce issues with noise and distortion. Bit-by-bit transfer of binary messages is known as serial data transmission. One connecting link is all that is needed because the bits share the transmission medium time-shared.

Because only one connecting line is needed, serial data transmission is a comparatively slow data transfer method even if it is much simpler and less expensive. Serial data transfer is helpful in situations where high speed is not necessary. Long-distance data communications employ serial transmission, but short-distance data communications and computer-to-computer communications use parallel communication.

Transmission Modes:

There are four modes of transmission for data communication circuits:

Simplex mode (SX) is a one-way communication channel, like a one-way street. In a connection, two devices can only communicate among themselves; the other can only receive. One example is the broadcasting of commercial radio. Other names for simplex lines are receive-only, transmit-only, and one-way-only lines.

Every station can send and receive in half-duplex (HDX) mode, but not simultaneously. One device can only receive when it is sending, and vice versa. When communication in both directions is not required at the same period and the channel’s full capacity may be used for each direction, the half-duplex mode is employed. A good example of push-to-talk (PTT) is when someone feels sad or pressed on a Citizens Band (CB) radio.

Both stations can transmit and receive concurrently while using full-duplex mode (FDX), also known as duplex. The telephone network is a typical illustration of full-duplex communication. When constant bidirectional communication is needed, the full-duplex mode is employed. It is necessary to divide the channel’s capacity between the two directions.

Transmission in both directions can occur frequently in full/full duplex (F/FDX) mode, but not between the same two stations (i.e., station 1 transmitting to station 2, while receiving from station 3). F/FDX can only operate on circuits with multiple points. One benefit of the postal system is that letters can be sent and received simultaneously from different addresses.

Data Communications Networks

A data communications network is any collection of linked computers, and networking is about exchanging resources amongst computers over a data communications network. The four most crucial factors in a data communications network are security, dependability, performance, and transmission rate.

Q1: What is data communication, and why is it essential in modern electronics and communication systems?

Data communication refers to the electronic transmission of information (data) between two or more devices over a communication channel.
It’s essential in modern systems as it enables applications like the internet, mobile networks, IoT devices, and industrial automation.
Data communication facilitates the exchange of information, making our lives more connected and efficient.

Q2: Explain the difference between analog and digital data communication, and their advantages.

Analog communication transmits information as continuous signals that vary in amplitude or frequency, while digital communication transmits information as discrete binary values (0s and 1s).
Analog communication is simpler and less expensive but susceptible to noise and distortion.
Digital communication offers better noise immunity, error correction capabilities, and easier integration with computers.

Q3: What are the key components of a data communication system, and how do they work together?

A data communication system typically consists of:

Source: Generates the data to be transmitted (e.g., computer, sensor).
Transmitter: Converts the data into a suitable format for transmission (e.g., modem).
Transmission Medium: The physical path data travels (e.g., wires, fiber optic cables, wireless channels).
Receiver: Converts the received signal to its original format (e.g., modem).
Destination: Receives the transmitted data (e.g., computer, display).

These components work together to ensure reliable and efficient data transfer.

Q4: What are the different transmission modes in data communication, and how do they affect performance?

The main transmission modes are:

Simplex: Data flows in only one direction (e.g., radio broadcasting).
Half-duplex: Data can flow in both directions, but not simultaneously (e.g., walkie-talkies).
Full-duplex: Data can flow in both directions simultaneously (e.g., telephone conversations).

Selecting the most suitable transmission mode involves considering trade-offs between speed, efficiency, and cost based on the specific application’s requirements.

Q5: What are the key protocols and standards that facilitate data communication, and why are they essential for ensuring seamless connectivity?

Protocols and standards ensure interoperability between different devices and systems. Some common examples include:

TCP/IP: The foundation of the internet, defining how data is packetized, addressed, and routed.
Ethernet: A widely used standard for local area networks (LANs).
Wi-Fi: A wireless networking standard for connecting devices to LANs and the internet.
Bluetooth: A short-range wireless standard for connecting devices like headphones and keyboards.