1. Data communication refers to the exchange of data between two or more connected devices via a communication medium. It involves a sender, receiver, message, communication media, and protocols.
2. Components of data communication systems include the sender, receiver, message, communication media used to transmit the message, and protocols that govern communication.
3. Transmission media can be wired (guided) like twisted pair, coaxial cable, fiber optic cable or wireless (unguided) through air using electromagnetic waves.
In this slide, you will know about the basic of data communication
* What is Data Communication?
* Types and characteristics of Data Communication
* Components of Data Communication
* Computer Networks
* Transmission medium
* Fiber optic cable (advantage and disadvantage)
Polling is a method for controlling access to a shared medium where a primary station periodically polls or queries secondary stations on the network to see if they have any data to transmit. The primary station controls the link and knows when the medium is idle, but does not know the status of the receivers. It alerts receivers when it is ready to transmit and waits for an acknowledgement before sending data. The primary station must also poll each secondary station in turn when it is ready to receive data to see if any station has data to transmit. Polling allows for predictable access times but has drawbacks such as high dependence on the reliability of the primary station and reduced throughput under low loads.
ISO is an organization which is established in 1947.
AN ISO standard that covers all aspects of network communication.
Network communication model is defined in OSI.
It was first introduced in the late 1970s, 1983
This document discusses several common networking devices and their functions. It describes hubs, switches, bridges, routers, gateways, CSU/DSUs, NICs, ISDN adapters, modems, and firewalls. Hubs broadcast traffic to all ports, wasting bandwidth, while switches only forward frames to their destination port. Bridges operate at the data link layer and routers at the network layer. Gateways perform protocol translation. NICs connect devices to the network. Modems convert digital to analog signals for transmission over phone lines. Firewalls control network access for security.
This document discusses various topics related to data transmission including:
- Data transmission involves transferring electromagnetic signals over a physical communication channel like copper wires or wireless channels.
- Transmission modes can be parallel (multiple bits sent at once) or serial (one bit at a time). Serial transmission is further divided into asynchronous and synchronous types.
- Asynchronous transmission groups data into start-stop bit sequences while synchronous transmission uses device-generated clocks for synchronization.
This document provides an introduction to data communications and telecommunications. It discusses what data communication is, the history of telecommunications including key inventions and developments, features of communication like senders, receivers, and message types. It also covers network applications, application service providers, business data communication issues, introduces different types of networks and topologies, store-and-forward systems, and the major data communication frameworks of OSI and TCP/IP. Key concepts like sessions, nodes, links, paths, circuits, and packetizing are also defined.
S.VIJAYALAKSHMI M.SC(CS) discusses Media Access Control and multiple access protocols. The main task of MAC protocols is to minimize collisions and utilize bandwidth by determining when nodes can access the shared channel, what to do when the channel is busy, and how to handle collisions. Early protocols like Aloha and slotted Aloha were inefficient at high loads due to many collisions. CSMA protocols reduce collisions by having nodes listen first before transmitting, but collisions are still possible due to propagation delays.
In this slide, you will know about the basic of data communication
* What is Data Communication?
* Types and characteristics of Data Communication
* Components of Data Communication
* Computer Networks
* Transmission medium
* Fiber optic cable (advantage and disadvantage)
Polling is a method for controlling access to a shared medium where a primary station periodically polls or queries secondary stations on the network to see if they have any data to transmit. The primary station controls the link and knows when the medium is idle, but does not know the status of the receivers. It alerts receivers when it is ready to transmit and waits for an acknowledgement before sending data. The primary station must also poll each secondary station in turn when it is ready to receive data to see if any station has data to transmit. Polling allows for predictable access times but has drawbacks such as high dependence on the reliability of the primary station and reduced throughput under low loads.
ISO is an organization which is established in 1947.
AN ISO standard that covers all aspects of network communication.
Network communication model is defined in OSI.
It was first introduced in the late 1970s, 1983
This document discusses several common networking devices and their functions. It describes hubs, switches, bridges, routers, gateways, CSU/DSUs, NICs, ISDN adapters, modems, and firewalls. Hubs broadcast traffic to all ports, wasting bandwidth, while switches only forward frames to their destination port. Bridges operate at the data link layer and routers at the network layer. Gateways perform protocol translation. NICs connect devices to the network. Modems convert digital to analog signals for transmission over phone lines. Firewalls control network access for security.
This document discusses various topics related to data transmission including:
- Data transmission involves transferring electromagnetic signals over a physical communication channel like copper wires or wireless channels.
- Transmission modes can be parallel (multiple bits sent at once) or serial (one bit at a time). Serial transmission is further divided into asynchronous and synchronous types.
- Asynchronous transmission groups data into start-stop bit sequences while synchronous transmission uses device-generated clocks for synchronization.
This document provides an introduction to data communications and telecommunications. It discusses what data communication is, the history of telecommunications including key inventions and developments, features of communication like senders, receivers, and message types. It also covers network applications, application service providers, business data communication issues, introduces different types of networks and topologies, store-and-forward systems, and the major data communication frameworks of OSI and TCP/IP. Key concepts like sessions, nodes, links, paths, circuits, and packetizing are also defined.
S.VIJAYALAKSHMI M.SC(CS) discusses Media Access Control and multiple access protocols. The main task of MAC protocols is to minimize collisions and utilize bandwidth by determining when nodes can access the shared channel, what to do when the channel is busy, and how to handle collisions. Early protocols like Aloha and slotted Aloha were inefficient at high loads due to many collisions. CSMA protocols reduce collisions by having nodes listen first before transmitting, but collisions are still possible due to propagation delays.
This document discusses routing protocols RIP and OSPF. It begins with an introduction to routing and defines routing protocols as how routers communicate and share information to select optimal routes. It then provides details on RIP, including its hop count limit of 15, periodic updates every 30 seconds, and versions RIPv1 and RIPv2. The document also covers OSPF, describing how it uses the Dijkstra algorithm and allows for scalability. Configuration examples are given for implementing both RIP and OSPF on sample networks.
Networking devices like repeaters, hubs, bridges, routers, switches, and gateways are used to connect nodes and networks. Repeaters extend network distance by boosting signals. Hubs connect workstations into a LAN by resending data frames to all ports. Bridges are more intelligent repeaters that examine MAC addresses to form tables. Routers operate at the network layer, can connect similar and dissimilar networks, and determine the shortest route between destinations. Switches form dedicated connections between ports like bridges but have multiple ports. Gateways link all seven layers of the OSI model when networks differ at any layer, primarily handling email protocols.
This Presentation covers:
Basics of data communications
Network Elements
Introduction to Protocols
Bridges, Routers, HUB, switch, gateway
Packet Switching Concepts
CCNA Basic Switching and Switch ConfigurationDsunte Wilson
This document provides an overview of basic switching concepts and Cisco switch configuration. It explains Ethernet and how switches work to segment networks and reduce collisions. Switches operate at the data link layer and learn MAC addresses to forward frames efficiently. The document discusses switch configuration using commands like hostname, interface, duplex, and port security. It compares switching methods like store-and-forward and cut-through forwarding. The summary reiterates how switches divide collision domains to improve performance over shared-medium Ethernet.
The document discusses the Domain Name System (DNS) and how it works to translate domain names to IP addresses. It explains the hierarchical structure of domain names from top-level domains down to subdomains. It also describes how DNS servers store and retrieve resource records containing IP address mappings for domain names. Finally, it provides examples of common resource record types used in the DNS.
O documento descreve a tecnologia Frame Relay, incluindo sua evolução a partir do protocolo X.25, seu funcionamento por meio de circuitos virtuais identificados por DLCIs, e sua capacidade de fornecer conexões de rede flexíveis e de baixo custo em topologias como estrela, malha completa e malha parcial.
This study guide is intended to provide those pursuing the CCNA certification with a framework of what concepts need to be studied. This is not a comprehensive document containing all the secrets of the CCNA, nor is it a “braindump” of questions and answers.
I sincerely hope that this document provides some assistance and clarity in your studies.
The document discusses the network layer in computer networking. It describes how the network layer is responsible for routing packets from their source to destination. It covers different routing algorithms like distance vector routing and link state routing. It also compares connectionless and connection-oriented services, as well as datagram and virtual circuit subnets. Key aspects of routing algorithms like optimality, stability, and fairness are defined.
Flow control and error control techniques in the data link layer protocolmdmuaj
This document provides information about flow control and error control techniques in data link layer protocols. It discusses three mechanisms: stop-and-wait, go-back-N ARQ, and selective-repeat ARQ. Stop-and-wait flow control involves a sender keeping a copy of the last frame until receiving an acknowledgement and resending any unacknowledged frames. Cyclic redundancy check (CRC) is described as an error detection code used to detect accidental changes to data by dividing the data and CRC by a generator polynomial. The document also includes an explanation of how CRC works at the sender and receiver.
Spanning Tree Protocol (STP) is standardized as IEEE 802.1D.
Is a network protocol that ensures a loop-free topology for any bridged Ethernet local area network.
This document discusses layer 2 switching fundamentals, including communication methods in LANs such as unicast, broadcast, and multicast. It describes how switches operate including forwarding frames based on the destination address and address table lookups. The document also covers collision domains, broadcast domains, and how switches help segment networks to reduce collisions and broadcast traffic.
Multiplexing is a technique that allows multiple signals to be transmitted over a single data link by combining or dividing the signals. There are different types of multiplexing including frequency division multiplexing (FDM), wavelength division multiplexing (WDM), and time division multiplexing (TDM). FDM and WDM are analog techniques that modulate signals onto different carrier frequencies or wavelengths. TDM is a digital technique that assigns fixed or dynamic time slots to different signals to allow transmission over the same link.
This document discusses basic networking components. It introduces networking and its purposes like sharing resources and communication. It describes common networking devices like hubs, switches, routers, modems, network interface cards, and repeaters. It provides an overview of their functions and compares switches and hubs. The document also outlines common network platforms of client-server and peer-to-peer.
Data Communication & Computer Networks : Serial and parellel transmissionDr Rajiv Srivastava
The document discusses serial and parallel transmission. It provides details on synchronous and asynchronous serial transmission. Asynchronous transmission transmits bytes individually with start and stop bits between each byte, while synchronous transmission transmits blocks of bytes continuously at high speed using synchronization patterns. Asynchronous transmission is simpler but slower, while synchronous transmission is faster but requires accurate clock synchronization between transmitter and receiver. The document compares the two serial transmission methods and also discusses their advantages and disadvantages.
Data communication : entails electronically exchanging data or information. It is the movement of computer information from one point to another by means of electrical or optical transmission system. This system often is called data communication networks.
The document discusses security issues in mobile ad hoc networks (MANETs). It begins by introducing MANETs and noting their vulnerability to attacks due to lack of centralized authority. It then covers security goals, types of attacks (passive vs. active; internal vs. external), examples of passive attacks like eavesdropping and active attacks like jamming and wormholes. The document also discusses security schemes like intrusion detection and secure routing techniques. It concludes by identifying research issues around improving MANET security.
Lesson 5 data communication and networking (136 kb)IMRAN KHAN
This document introduces data communication and computer networks. It discusses how computer networking allows users to share data and programs between computers regardless of location. The objectives are to learn about the basic elements of data communication systems, communication protocols, transmission modes, computer networks, and network types. It describes the basic components of a communication system including a sender, medium, and receiver. Data communication involves the electrical or electromagnetic transmission of encoded data signals across communication channels or media.
The document provides an overview of computer networks and data communication. It defines key terms like data, information, data communication and its components. It describes different network types (LAN, MAN, WAN), transmission modes (simplex, half-duplex, full-duplex), network topologies (bus, star, ring, mesh, tree), and protocols (TCP/IP, OSI model). It discusses network structure, applications, and risks. The document is serving as an introduction to the topic of computer networks and data communication for a course.
This document discusses routing protocols RIP and OSPF. It begins with an introduction to routing and defines routing protocols as how routers communicate and share information to select optimal routes. It then provides details on RIP, including its hop count limit of 15, periodic updates every 30 seconds, and versions RIPv1 and RIPv2. The document also covers OSPF, describing how it uses the Dijkstra algorithm and allows for scalability. Configuration examples are given for implementing both RIP and OSPF on sample networks.
Networking devices like repeaters, hubs, bridges, routers, switches, and gateways are used to connect nodes and networks. Repeaters extend network distance by boosting signals. Hubs connect workstations into a LAN by resending data frames to all ports. Bridges are more intelligent repeaters that examine MAC addresses to form tables. Routers operate at the network layer, can connect similar and dissimilar networks, and determine the shortest route between destinations. Switches form dedicated connections between ports like bridges but have multiple ports. Gateways link all seven layers of the OSI model when networks differ at any layer, primarily handling email protocols.
This Presentation covers:
Basics of data communications
Network Elements
Introduction to Protocols
Bridges, Routers, HUB, switch, gateway
Packet Switching Concepts
CCNA Basic Switching and Switch ConfigurationDsunte Wilson
This document provides an overview of basic switching concepts and Cisco switch configuration. It explains Ethernet and how switches work to segment networks and reduce collisions. Switches operate at the data link layer and learn MAC addresses to forward frames efficiently. The document discusses switch configuration using commands like hostname, interface, duplex, and port security. It compares switching methods like store-and-forward and cut-through forwarding. The summary reiterates how switches divide collision domains to improve performance over shared-medium Ethernet.
The document discusses the Domain Name System (DNS) and how it works to translate domain names to IP addresses. It explains the hierarchical structure of domain names from top-level domains down to subdomains. It also describes how DNS servers store and retrieve resource records containing IP address mappings for domain names. Finally, it provides examples of common resource record types used in the DNS.
O documento descreve a tecnologia Frame Relay, incluindo sua evolução a partir do protocolo X.25, seu funcionamento por meio de circuitos virtuais identificados por DLCIs, e sua capacidade de fornecer conexões de rede flexíveis e de baixo custo em topologias como estrela, malha completa e malha parcial.
This study guide is intended to provide those pursuing the CCNA certification with a framework of what concepts need to be studied. This is not a comprehensive document containing all the secrets of the CCNA, nor is it a “braindump” of questions and answers.
I sincerely hope that this document provides some assistance and clarity in your studies.
The document discusses the network layer in computer networking. It describes how the network layer is responsible for routing packets from their source to destination. It covers different routing algorithms like distance vector routing and link state routing. It also compares connectionless and connection-oriented services, as well as datagram and virtual circuit subnets. Key aspects of routing algorithms like optimality, stability, and fairness are defined.
Flow control and error control techniques in the data link layer protocolmdmuaj
This document provides information about flow control and error control techniques in data link layer protocols. It discusses three mechanisms: stop-and-wait, go-back-N ARQ, and selective-repeat ARQ. Stop-and-wait flow control involves a sender keeping a copy of the last frame until receiving an acknowledgement and resending any unacknowledged frames. Cyclic redundancy check (CRC) is described as an error detection code used to detect accidental changes to data by dividing the data and CRC by a generator polynomial. The document also includes an explanation of how CRC works at the sender and receiver.
Spanning Tree Protocol (STP) is standardized as IEEE 802.1D.
Is a network protocol that ensures a loop-free topology for any bridged Ethernet local area network.
This document discusses layer 2 switching fundamentals, including communication methods in LANs such as unicast, broadcast, and multicast. It describes how switches operate including forwarding frames based on the destination address and address table lookups. The document also covers collision domains, broadcast domains, and how switches help segment networks to reduce collisions and broadcast traffic.
Multiplexing is a technique that allows multiple signals to be transmitted over a single data link by combining or dividing the signals. There are different types of multiplexing including frequency division multiplexing (FDM), wavelength division multiplexing (WDM), and time division multiplexing (TDM). FDM and WDM are analog techniques that modulate signals onto different carrier frequencies or wavelengths. TDM is a digital technique that assigns fixed or dynamic time slots to different signals to allow transmission over the same link.
This document discusses basic networking components. It introduces networking and its purposes like sharing resources and communication. It describes common networking devices like hubs, switches, routers, modems, network interface cards, and repeaters. It provides an overview of their functions and compares switches and hubs. The document also outlines common network platforms of client-server and peer-to-peer.
Data Communication & Computer Networks : Serial and parellel transmissionDr Rajiv Srivastava
The document discusses serial and parallel transmission. It provides details on synchronous and asynchronous serial transmission. Asynchronous transmission transmits bytes individually with start and stop bits between each byte, while synchronous transmission transmits blocks of bytes continuously at high speed using synchronization patterns. Asynchronous transmission is simpler but slower, while synchronous transmission is faster but requires accurate clock synchronization between transmitter and receiver. The document compares the two serial transmission methods and also discusses their advantages and disadvantages.
Data communication : entails electronically exchanging data or information. It is the movement of computer information from one point to another by means of electrical or optical transmission system. This system often is called data communication networks.
The document discusses security issues in mobile ad hoc networks (MANETs). It begins by introducing MANETs and noting their vulnerability to attacks due to lack of centralized authority. It then covers security goals, types of attacks (passive vs. active; internal vs. external), examples of passive attacks like eavesdropping and active attacks like jamming and wormholes. The document also discusses security schemes like intrusion detection and secure routing techniques. It concludes by identifying research issues around improving MANET security.
Lesson 5 data communication and networking (136 kb)IMRAN KHAN
This document introduces data communication and computer networks. It discusses how computer networking allows users to share data and programs between computers regardless of location. The objectives are to learn about the basic elements of data communication systems, communication protocols, transmission modes, computer networks, and network types. It describes the basic components of a communication system including a sender, medium, and receiver. Data communication involves the electrical or electromagnetic transmission of encoded data signals across communication channels or media.
The document provides an overview of computer networks and data communication. It defines key terms like data, information, data communication and its components. It describes different network types (LAN, MAN, WAN), transmission modes (simplex, half-duplex, full-duplex), network topologies (bus, star, ring, mesh, tree), and protocols (TCP/IP, OSI model). It discusses network structure, applications, and risks. The document is serving as an introduction to the topic of computer networks and data communication for a course.
This document provides an overview of key concepts in data communication and networks. It defines common terminology like data, information, communication, networks, and nodes. It describes what data communication is and its main components, including the message, sender, receiver, medium, and protocols. It discusses data representation, data flow modes (simplex, half-duplex, full-duplex), network criteria like performance and reliability, and different physical network topologies like bus, star, and ring. The document serves as an introductory lecture on data communication fundamentals.
Computer Networks for Computer Science Studentrprajat007
This document provides information about data communication systems and their components. It discusses the following key points in 3 sentences:
Data communication systems allow exchange of data between devices via transmission mediums like wires. Effective systems ensure delivery of data to the correct destination, accuracy of the data, timely delivery, and minimal jitter or packet arrival variation. The core components of data communication systems include messages, senders and receivers, transmission mediums, protocols that establish communication rules, and various transmission modes like simplex, half-duplex, and full-duplex.
A computer network allows devices to exchange data and share resources. It consists of nodes connected by communication links using either cable or wireless media. There are various network topologies including mesh, star, bus, ring, tree and hybrid. Computer networks have many applications such as sharing resources like printers, sharing information between devices, electronic communication via email and video conferencing, and backing up critical data for support. The effectiveness of a network depends on timely and accurate delivery of data to the correct destinations.
Lesson 4 communication and computer network (123 kb)IMRAN KHAN
Communication between computers has increased with advancements in data communication facilities, allowing users to access computers remotely. A computer network connects multiple computers over communication channels to share data and programs across geographical locations. It consists of senders and receivers of messages connected by a medium like cables, wireless signals, or satellites. Protocols define how computers transmit data over the network by sequencing packets, routing them efficiently, and detecting and correcting errors.
A computer network connects devices through transmission mediums like wires or cables. It allows devices to send and receive stored data. There are several network topologies that determine how devices are interconnected, including bus, star, ring, tree and mesh. Bus topology connects all devices to a single backbone cable. Star topology connects each device to a central hub or switch. Ring topology connects devices in an endless loop. Tree and mesh topologies provide multiple connections between devices in a hierarchical or fully/partially connected manner respectively.
This document provides an introduction to data communication and transmission. It defines data and describes how data is communicated from a source to a receiver. It explains the components of a data communication system including the message, sender, receiver, medium, and protocols. Protocols are defined as sets of rules that govern communication and their functions like data sequencing, routing, formatting, flow control, error control, and security are described. The modes of data transmission - simplex, half-duplex, and full-duplex - are defined. Serial and parallel transmission methods are also explained along with asynchronous and synchronous serial transmission types.
This document discusses data communication and networks. It defines data communication as the process of transferring data electronically from one place to another. The basic elements are a sender, receiver, and medium. Communication protocols establish rules for exchanging information and perform functions like data sequencing, routing, flow control, and error control. Data transmission can be digital, analog, asynchronous, or synchronous. Wired transmission media include twisted pair cable, coaxial cable, and fiber optics, while wireless includes radio waves, microwaves, and infrared.
This document provides an overview of communication networks, including:
1. Communication networks are composed of nodes and branches to facilitate the movement of information. Nodes are connection points and branches are transmission mediums like wires or radio channels.
2. There are different types of communication networks including telephone networks, computer networks, broadcast networks, and integrated networks. Telephone networks traditionally used circuit switching while computer networks use packet switching.
3. Communication networks are organized hierarchically, with the core network carrying the most traffic and access networks connecting individual users. The core network uses high-capacity optical fiber transmission.
The document discusses computer networks and data communication. It defines a computer network as a group of interconnected computers that allows sharing of resources and information. The key components of a data communication system are sender, receiver, message, medium, and protocol. Communication can be simplex, half-duplex or full-duplex depending on the direction of data flow. Common network topologies include bus, star, ring and mesh. Local area networks (LANs) connect devices within a building, metropolitan area networks (MANs) span a city, and wide area networks (WANs) encompass large geographic areas or the entire world. The Internet is an example of interconnected networks.
This document provides an overview of data communication and computer networks. It discusses:
- The key components of a data communication system including the message, sender, receiver, transmission medium, and protocols.
- Types of data transmission including parallel, serial, synchronous, asynchronous, analog, and digital.
- Network devices like hubs, switches, repeaters, and bridges and their functions in connecting and transmitting data in a network.
- Challenges of data transmission including attenuation, distortion, noise, and their solutions.
This document discusses data communication and computer networks. It defines data communication as the exchange of data between devices via transmission medium. A data communication system has five components: sender, receiver, message, medium, and protocol. Communication can be simplex, half-duplex, or full-duplex. The document then discusses networks, defining them as connected devices and discussing LANs (local area networks), MANs (metropolitan area networks), and WANs (wide area networks). It also covers network topologies like mesh, star, bus, ring and hybrid configurations.
This document discusses data communication and computer networks. It covers the following key points:
- Data communication systems have five components: a sender, receiver, message, medium, and protocol. Communication can be simplex, half-duplex, or full-duplex.
- A computer network connects devices like computers and allows them to share resources and information. Common network types include local area networks and the Internet. Networks use distributed processing and must meet criteria for performance, reliability, and security.
- Physical network topologies include mesh, star, bus, and ring configurations. A topology defines how devices are linked together physically in a network.
Computer Networks Unit 1 Introduction and Physical Layer Dr. SELVAGANESAN S
This document discusses data communication and computer networks. It defines data communication as the exchange of data between devices via transmission medium. A data communication system has five components: sender, receiver, message, medium, and protocol. Communication can be simplex, half-duplex, or full-duplex. The document also defines networks, explaining that a network allows interconnected devices to communicate and share resources. Local area networks (LANs), metropolitan area networks (MANs), and wide area networks (WANs) are described as the main categories of networks.
1. Data communication systems allow exchange of data between devices via transmission mediums like wires. They must reliably and accurately deliver data to intended recipients in a timely manner.
2. Communication can occur in simplex, half-duplex, or full-duplex mode depending on whether devices can transmit and receive simultaneously or one at a time.
3. Computer networks connect devices through physical topologies like mesh, star, bus or ring and logical protocols to exchange messages between senders and receivers.
This document provides an overview of data communication concepts. It discusses that data communication requires hardware devices and software to exchange data via transmission mediums. There are four key characteristics of effective data communication systems: delivery, accuracy, timeliness, and jitter. Data can be transmitted through various modes including unicasting, multicasting, and broadcasting. Components of data communication systems include messages, senders, receivers, transmission mediums, and protocols. The document also discusses topics such as data transmission methods, network devices like hubs and switches, and challenges in data transmission like attenuation, distortion, and noise.
Unit dsffffdgdigigjgkjxclvjxcvxcvxciofjgerioutsiosrut1.pptxgurjardeep68
This document provides an overview of key concepts in data communication and computer networks. It discusses data communication components and characteristics, transmission modes (simplex, half-duplex, full-duplex), network topologies (star, bus, ring, mesh, hybrid), network devices (hub, switch, router, modem, bridge, repeater), types of computer networks (LAN, MAN, WAN), protocols, and standards. The document serves as the syllabus for a unit on data communication fundamentals.
1. The document discusses the components of a data communication system including the message, sender, receiver, transmission medium, and protocols.
2. It describes the five main components: the message being communicated, the sender who transmits the message, the receiver that receives the message, the transmission medium like cables or wireless that connects the sender and receiver, and the set of protocols that govern the communication.
3. It also discusses different network types like LAN, PAN, MAN, and WAN and provides examples to explain each type.
This document provides definitions and explanations of key concepts in computer networks:
- A computer network connects two or more devices to share resources and files using common protocols.
- Networks have five basic components: messages, senders, receivers, transmission media, and protocols.
- Communication can occur in simplex, half-duplex, or full-duplex mode depending on whether devices can transmit and receive simultaneously.
- Important criteria for networks are performance, reliability, and security.
Elevate Your Nonprofit's Online Presence_ A Guide to Effective SEO Strategies...TechSoup
Whether you're new to SEO or looking to refine your existing strategies, this webinar will provide you with actionable insights and practical tips to elevate your nonprofit's online presence.
Leveraging Generative AI to Drive Nonprofit InnovationTechSoup
In this webinar, participants learned how to utilize Generative AI to streamline operations and elevate member engagement. Amazon Web Service experts provided a customer specific use cases and dived into low/no-code tools that are quick and easy to deploy through Amazon Web Service (AWS.)
This presentation was provided by Racquel Jemison, Ph.D., Christina MacLaughlin, Ph.D., and Paulomi Majumder. Ph.D., all of the American Chemical Society, for the second session of NISO's 2024 Training Series "DEIA in the Scholarly Landscape." Session Two: 'Expanding Pathways to Publishing Careers,' was held June 13, 2024.
Andreas Schleicher presents PISA 2022 Volume III - Creative Thinking - 18 Jun...EduSkills OECD
Andreas Schleicher, Director of Education and Skills at the OECD presents at the launch of PISA 2022 Volume III - Creative Minds, Creative Schools on 18 June 2024.
THE SACRIFICE HOW PRO-PALESTINE PROTESTS STUDENTS ARE SACRIFICING TO CHANGE T...indexPub
The recent surge in pro-Palestine student activism has prompted significant responses from universities, ranging from negotiations and divestment commitments to increased transparency about investments in companies supporting the war on Gaza. This activism has led to the cessation of student encampments but also highlighted the substantial sacrifices made by students, including academic disruptions and personal risks. The primary drivers of these protests are poor university administration, lack of transparency, and inadequate communication between officials and students. This study examines the profound emotional, psychological, and professional impacts on students engaged in pro-Palestine protests, focusing on Generation Z's (Gen-Z) activism dynamics. This paper explores the significant sacrifices made by these students and even the professors supporting the pro-Palestine movement, with a focus on recent global movements. Through an in-depth analysis of printed and electronic media, the study examines the impacts of these sacrifices on the academic and personal lives of those involved. The paper highlights examples from various universities, demonstrating student activism's long-term and short-term effects, including disciplinary actions, social backlash, and career implications. The researchers also explore the broader implications of student sacrifices. The findings reveal that these sacrifices are driven by a profound commitment to justice and human rights, and are influenced by the increasing availability of information, peer interactions, and personal convictions. The study also discusses the broader implications of this activism, comparing it to historical precedents and assessing its potential to influence policy and public opinion. The emotional and psychological toll on student activists is significant, but their sense of purpose and community support mitigates some of these challenges. However, the researchers call for acknowledging the broader Impact of these sacrifices on the future global movement of FreePalestine.
Beyond Degrees - Empowering the Workforce in the Context of Skills-First.pptxEduSkills OECD
Iván Bornacelly, Policy Analyst at the OECD Centre for Skills, OECD, presents at the webinar 'Tackling job market gaps with a skills-first approach' on 12 June 2024
How Barcodes Can Be Leveraged Within Odoo 17Celine George
In this presentation, we will explore how barcodes can be leveraged within Odoo 17 to streamline our manufacturing processes. We will cover the configuration steps, how to utilize barcodes in different manufacturing scenarios, and the overall benefits of implementing this technology.
Temple of Asclepius in Thrace. Excavation resultsKrassimira Luka
The temple and the sanctuary around were dedicated to Asklepios Zmidrenus. This name has been known since 1875 when an inscription dedicated to him was discovered in Rome. The inscription is dated in 227 AD and was left by soldiers originating from the city of Philippopolis (modern Plovdiv).
Philippine Edukasyong Pantahanan at Pangkabuhayan (EPP) CurriculumMJDuyan
(𝐓𝐋𝐄 𝟏𝟎𝟎) (𝐋𝐞𝐬𝐬𝐨𝐧 𝟏)-𝐏𝐫𝐞𝐥𝐢𝐦𝐬
𝐃𝐢𝐬𝐜𝐮𝐬𝐬 𝐭𝐡𝐞 𝐄𝐏𝐏 𝐂𝐮𝐫𝐫𝐢𝐜𝐮𝐥𝐮𝐦 𝐢𝐧 𝐭𝐡𝐞 𝐏𝐡𝐢𝐥𝐢𝐩𝐩𝐢𝐧𝐞𝐬:
- Understand the goals and objectives of the Edukasyong Pantahanan at Pangkabuhayan (EPP) curriculum, recognizing its importance in fostering practical life skills and values among students. Students will also be able to identify the key components and subjects covered, such as agriculture, home economics, industrial arts, and information and communication technology.
𝐄𝐱𝐩𝐥𝐚𝐢𝐧 𝐭𝐡𝐞 𝐍𝐚𝐭𝐮𝐫𝐞 𝐚𝐧𝐝 𝐒𝐜𝐨𝐩𝐞 𝐨𝐟 𝐚𝐧 𝐄𝐧𝐭𝐫𝐞𝐩𝐫𝐞𝐧𝐞𝐮𝐫:
-Define entrepreneurship, distinguishing it from general business activities by emphasizing its focus on innovation, risk-taking, and value creation. Students will describe the characteristics and traits of successful entrepreneurs, including their roles and responsibilities, and discuss the broader economic and social impacts of entrepreneurial activities on both local and global scales.
3. 1. Concept of Communication
The term “Data Communication” comprises two words: Data and
Communication. Data can be any text, image, audio, video, and multimedia
files. Communication is an act of sending or receiving data. Thus, data
communication refers to the exchange of data between two or more
networked or connected devices. These devices must be capable of sending
and receiving data over a communication medium. Examples of such devices
include personal computers, mobile phones, laptops, etc. As we can see in
Figure 1, four different types of devices — computer (Clients), printer, server
and switch are connected to build the network. These devices are connected
through a media to the network, which carry information from one end to
other end.
Figure 1 A Simple network of computing devices
4. 2. Components of Data communication
1. Sender
A sender is a computer or any such device, which is capable of sending
data over a network. It can be a computer, mobile phone, smart watch,
video recording device, etc.
2. Receiver
A receiver is a computer or any such device, which is capable of
receiving data from the network. It can be any computer, printer, laptop,
mobile phone, television, etc. In computer communication, the sender and
receiver are known as nodes in a network.
3. Message
The data or information needs to be exchanged between the sender and
the receiver. Messages can be in the form of text, number, image, audio,
video, etc.
4. Communication media
The message travels between source and destination through the path.
It is also called medium or link, which is either wired or wireless. For
example, a television cable, telephone cable, Ethernet cable, satellite link,
microwaves, etc.
5. Protocols
It is a set of rules that need to be followed by the communicating parties
in order to have successful and reliable data communication. You have
already come across protocols such as Ethernet and HTTP. Figure 2 show
the components of data communication.
Figure 2 Data communication components
5. 3. Measuring Capacity of Communication Media
In data communication, the transmission medium is also known as
channel. The capacity of a channel is the maximum amount of signals or
traffic that a channel can carry. It is measured in terms of bandwidth and data
transfer rate as described below:
3.1 Bandwidth
Bandwidth of a channel is the range of frequencies available for
transmission of data through that channel. Higher the bandwidth, higher the
data transfer rate. Normally, bandwidth is the difference of maximum and
minimum frequency contained in the composite signals. Bandwidth is
measured in Hertz (Hz).
1 KHz =1000 Hz
1 MHz =1000 KHz = 1000000 Hz
3.2 Data Transfer Rate
Data travels in the form of signals over a channel. One signal carries
one or more bits over the channel. Data transfer rate is the number of bits
transmitted between source and destination in one second. It is also known
as bit rate. It is measured in terms of bits per second (bps). The higher units
for data transfer rates are:
1 Kbps=210 bps=1024 bps
1 Mbps=220 bps=1024 Kbps
1 Gbps=230 bps=1024 Mbps
1 Tbps=240 bps=1024 Gbps
Activity 1
Find out how many
hertz is 10
Megahertz?
Activity 2
Find out how many
Gbps is 6 Tbps?
6. Example: A user wants to upload a text document at the rate of 10 pages per
20 second. What will be the required data rate of the channel? (Assume that 1
page contains 1600 characters and each character is of 8 bits).
Solution
Data rate=
(10∗1600∗8)
20
= 6400bps= 6.25kbps
4. Types of Data Communication
Data communication is the transmission of digital messages to external
devices. If you look around your house, you will see many examples of data
communication at work. Your cable system, your home phone and even your
computer all work based on varying types of data transfer. The process of
transmitting a message occurs millions of time a day without any of us being
aware of it. Today's recent data transfer methods include many complex
concepts, but we can still break down the process to a few basic types.
4.1 Simplex
A simplex communication system sends a message in only one
direction. The message source works as the transmitter. It sends the message
over the data channel to the receiver. The receiver is the destination of the
message. Examples of simplex data communication include radio stations
and TV broadcasts. With the simplex channel, there is no ability by the
receiver to respond to the message. For example, a radio station plays a song
on your car radio. The data transferred is the song. You do not have the
opportunity to send a message back via your car radio to the station.
7. 4.2 Half Duplex
A half-duplex data communication system provides messages in both
directions but only allows transfer in one direction at a time. Once a party begins
sending a transmission, the receiver must wait until the signal stops before
responding. If the two data transfers attempt to send at the same time, they both
fail. For instance, if you talk on a CB radio, you press a button and speak. If the
receiver attempts to press the button and speak at the same time, neither one of
you hear either message. The system is not capable of sending both ways
simultaneously.
4.3Full Duplex
A full duplex is a communication that works both ways at the same time.
Essentially, full duplex data communication is a set of two simplex channels, one
works as a forward channel and the other as a reserve channel. The two channels
link together at some point. An example of a full duplex communication system is
a landline telephone. When talking on a telephone, both parties have the ability to
speak at the same time. The data carried both ways through the telephone line,
runs simultaneously. Figure 3 show the Data communication types
Figure 3 Data Communication Types
8. 5. Switching Techniques
In a network having multiple devices, we are interested to know how to
connect the sender and receiver so that one-to-one communication is possible.
One solution is to make a dedicated connection between each pair of devices
(mesh topology) or between a central device and every other device (a star
topology). However, we know that such methods are costly in case of large
networks.
An alternative to this is switching whereby data is routed through various
nodes in a network. This switching process forms a temporary route for the
data to be transmitted. Two commonly used switching techniques are : Circuit
Switching and Packet Switching.
5.1 Circuit Switching
In circuit switching, before a communication starts, a dedicated path is
identified between the sender and the receiver. This path is a connected
sequence of links between network nodes. All packets follow the same path
established during the connection.
In earlier days, when we placed a telephone call, the switching equipment
within the telephone system finds out a physical path or channel all the way
from our telephone at home to the receiver’s telephone. This is an example of
circuit switching.
9. 5.2 Packet Switching
In packet switching, each information or message to be transmitted
between sender and receiver is broken down into smaller pieces, called
packets. These packets are then transmitted independently through the
network. Different packets of the same message may take different routes
depending on availability. Each packet has two parts — a header containing
the address of the destination and other information, and the main message
part. When all the packets reach the destination, they are reassembled and the
receiver receives the complete message.
Unlike circuit switching, a channel is occupied in packet switching only
during the transmission of the packet. On completion of the transmission, the
channel is available for transfer of packets from other communicating parties.
6. Transmission Media
A transmission medium can be anything that can carry signals or data between
the source (transmitter) and destination (receiver). For example, as we switch
on a ceiling fan or a light bulb, the electric wire is the medium that carries
electric current from switch to the fan or bulb. Two men are talking as shown
in Figure 4 Here the medium is air.
Figure 4 Two person communicating
10. In data communication, transmission media are the links that carry
messages between two or more communicating devices. Transmission can be
classified as guided or unguided. Figure 6 shows the classification of
communication media.
In guided transmission, there is a physical link made of wire/cable through
which data in terms of signals are propagated between the nodes. These are
usually metallic cable, fiber-optic cable, etc. They are also known as wired
media.
In unguided transmission, data travels in air in terms of electromagnetic
waves using an antenna. They are also known as wireless media.
Figure 5 Example in transmisson media
Activity 3
What is the
transmission media
in Figure5?
11. Figure 6 Classification of communication media
Dish-shaped antennas are used for sending and receiving data at longer
distances. These antennas are mounted on taller buildings so that it would be
in line-of-sight. Waves gradually become weaker and weaker after travelling
a certain distance through the air. Therefore, the aim of installing repeaters is
to regenerate the signals of the same energy.
6.1 Wired Transmission Media
Any physical link that can carry data in the form of signals belongs to the
category of wired transmission media. Three commonly used guided/wired
media for data transmission are, twisted pair, coaxial cable, and fiber optic
cable. Twisted-pair and coaxial cable carry the electric signals whereas the
optical fiber cable carries the light signals.
Communication Media
Wired Media
Twisted
Pair Cble
Co-axical
Cable
Fiber Optic
Cable
Wireless Media
Radio
Waves
Micro
Waves
Infrared
Waves
12. A. Twisted Pair Cable: is a type of wiring in which two conductors of a
single cable that are twisted together for the purposes of
improving electromagnetic compatibility. Both the copper wires are
insulated with plastic covers. Usually, a number of such pairs are
combined together and covered with a protective outer wrapping,
Figure 7 shows twisted pair cable.
Figure 7 Twisted pair cable
Each of the twisted pairs act as a single communication link. The use
of twisted configuration minimizes the effect of electrical interference
from similar pairs close by. Twisted pairs are less expensive and most
commonly used in telephone lines and LANs. These cables are of two
types: Unshielded twisted-pair (UTP) and Shielded twisted-pair
(STP). Figure 8 show the UTP and STP
Figure 8 STP and UTP
Activity 4
What is the different
between UTP and
STP?
13. B. Coaxial cable: is another type of data transmission medium. It is better
shielded and has more bandwidth than a twisted pair. As shown in
Figure 9, it has a copper wire at the core of the cable which is
surrounded with insulating material. The insulator is further surrounded
with an outer conductor (usually a copper mesh). This outer conductor
is wrapped in a plastic cover. The key to success of coaxial cable is its
shielded design that allows the cable's copper core to transmit data
quickly, without interference of environmental factors. These types of
cables are used to carry signals of higher frequencies to a longer
distance.
Figure 9 Coaxial cable
14. C. Fiber Optic Cable: also known as an optical-fiber cable, is an
assembly similar to an electrical cable, but containing one or
more optical fibers that are used to carry light. The optical fiber
elements are typically individually coated with plastic layers and
contained in a protective tube suitable for the environment where the
cable is used. Different types of cable are used for different
applications, for example, long distance telecommunication, or
providing a high-speed data connection between different parts of a
building. Figure 10 show the fiber optical cable
Figure 10 Fiber Optic cable