This document provides an overview of data communication and computer networks. It discusses key topics such as the basic communication model consisting of a message, sender, receiver, transmission medium, and protocol. It also describes different data transmission modes like simplex, half-duplex, and full-duplex. Additionally, it covers network categories including local area networks (LANs) and metropolitan area networks (MANs), as well as different physical network topologies like bus, star, ring, and mesh.
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.
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.
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 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
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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.
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.
Data communication and network
1. Introduction to Data Communication:
Data communication refers to the exchange of data between devices through a transmission medium such as cables, fiber optics, or wireless signals. The primary goal is to ensure the accurate and efficient transfer of data from one point to another. This process involves several key components:
Sender: The device that originates the message.
Receiver: The device that receives the message.
Transmission Medium: The physical path through which the message travels (e.g., twisted-pair wire, coaxial cable, fiber-optic cable, or air for wireless communication).
Message: The data being communicated, which can be in the form of text, numbers, images, audio, or video.
Protocol: A set of rules governing the data communication process, ensuring that the devices involved can interpret and understand the transmitted data correctly.
2. Types of Data Communication:
Simplex: Data flows in one direction only. Examples include keyboards and monitors.
Half-Duplex: Data flows in both directions, but not simultaneously. Walkie-talkies are a common example.
Full-Duplex: Data flows in both directions simultaneously, like in telephone conversations.
3. Network Fundamentals:
A network is a collection of interconnected devices that can communicate with each other. Networks can be categorized based on their size, range, and structure.
4. Types of Networks:
Local Area Network (LAN): Covers a small geographic area, like a home, office, or building. Typically uses Ethernet or Wi-Fi.
Wide Area Network (WAN): Spans a large geographic area, often a country or continent. The internet is the largest WAN.
Metropolitan Area Network (MAN): Covers a larger geographic area than a LAN but smaller than a WAN, such as a city.
Personal Area Network (PAN): A small network typically within the range of an individual, such as a Bluetooth connection between devices.
5. Network Topologies:
Bus Topology: All devices are connected to a single central cable.
Star Topology: All devices are connected to a central hub.
Ring Topology: Devices are connected in a circular fashion.
Mesh Topology: Devices are interconnected, with multiple paths for data transmission.
Hybrid Topology: A combination of two or more different topologies.
6. Protocols and Standards:
Protocols are rules that govern data communication. Some common protocols include:
TCP/IP (Transmission Control Protocol/Internet Protocol): The fundamental suite for internet communications.
HTTP (HyperText Transfer Protocol): Used for transferring web pages.
FTP (File Transfer Protocol): Used for transferring files.
SMTP (Simple Mail Transfer Protocol): Used for sending emails.
Standards ensure interoperability between different devices and networks. Some key organizations that develop and maintain these standards include:
IEEE (Institute of Electrical and Electronics Engineers)
IETF (Internet Engineering Task Force)
ISO (International Organization for Standardization).
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.
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.
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 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
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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.
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.
Data communication and network
1. Introduction to Data Communication:
Data communication refers to the exchange of data between devices through a transmission medium such as cables, fiber optics, or wireless signals. The primary goal is to ensure the accurate and efficient transfer of data from one point to another. This process involves several key components:
Sender: The device that originates the message.
Receiver: The device that receives the message.
Transmission Medium: The physical path through which the message travels (e.g., twisted-pair wire, coaxial cable, fiber-optic cable, or air for wireless communication).
Message: The data being communicated, which can be in the form of text, numbers, images, audio, or video.
Protocol: A set of rules governing the data communication process, ensuring that the devices involved can interpret and understand the transmitted data correctly.
2. Types of Data Communication:
Simplex: Data flows in one direction only. Examples include keyboards and monitors.
Half-Duplex: Data flows in both directions, but not simultaneously. Walkie-talkies are a common example.
Full-Duplex: Data flows in both directions simultaneously, like in telephone conversations.
3. Network Fundamentals:
A network is a collection of interconnected devices that can communicate with each other. Networks can be categorized based on their size, range, and structure.
4. Types of Networks:
Local Area Network (LAN): Covers a small geographic area, like a home, office, or building. Typically uses Ethernet or Wi-Fi.
Wide Area Network (WAN): Spans a large geographic area, often a country or continent. The internet is the largest WAN.
Metropolitan Area Network (MAN): Covers a larger geographic area than a LAN but smaller than a WAN, such as a city.
Personal Area Network (PAN): A small network typically within the range of an individual, such as a Bluetooth connection between devices.
5. Network Topologies:
Bus Topology: All devices are connected to a single central cable.
Star Topology: All devices are connected to a central hub.
Ring Topology: Devices are connected in a circular fashion.
Mesh Topology: Devices are interconnected, with multiple paths for data transmission.
Hybrid Topology: A combination of two or more different topologies.
6. Protocols and Standards:
Protocols are rules that govern data communication. Some common protocols include:
TCP/IP (Transmission Control Protocol/Internet Protocol): The fundamental suite for internet communications.
HTTP (HyperText Transfer Protocol): Used for transferring web pages.
FTP (File Transfer Protocol): Used for transferring files.
SMTP (Simple Mail Transfer Protocol): Used for sending emails.
Standards ensure interoperability between different devices and networks. Some key organizations that develop and maintain these standards include:
IEEE (Institute of Electrical and Electronics Engineers)
IETF (Internet Engineering Task Force)
ISO (International Organization for Standardization).
A network is a set of devices (often referred to as nodes) connected by communication links. A node can be a computer, printer, or any other device capable of sending and/or receiving data generated by other nodes on the network.
“Computer network’’ to mean a collection of autonomous computers interconnected by a single technology. Two computers are said to be interconnected if they are able to exchange information.
The connection need not be via a copper wire; fiber optics, microwaves, infrared, and communication satellites can also be used.
Networks come in many sizes, shapes and forms, as we will see later. They are usually connected together to make larger networks, with the Internet being the most well- known example of a network of networks.
There is considerable confusion in the literature between a computer network and a distributed system. The key distinction is that in a distributed system, a collection of independent computers appears to its users as a single coherent system. Usually, it has a single model or paradigm that it presents to the users. Often a layer of software on top of the operating system, called middleware, is responsible for implementing this model. A well-known example of a distributed system is the World Wide Web. It runs on top of the Internet and presents a model in which everything looks like a document (Web page).
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.
This document provides an overview of data communication systems and their key components and concepts. It discusses the basic components of a data communication system including messages, senders, receivers, transmission medium, and protocols. It then describes various concepts such as line configuration (point-to-point and multipoint), network topologies (bus, star, ring, mesh), transmission modes (simplex, half-duplex, full-duplex), and modems. The document focuses on explaining these fundamental building blocks and concepts to understand how data is transmitted between devices.
This document provides an overview of data communications and computer networks. It discusses the need for computer communication over distances, defines data communication, and describes the key components and characteristics of data communication systems. It also covers various data representation methods, transmission media, network topologies, categories of networks including LANs, MANs and WANs, and the importance of protocols and standards in networking.
A network is a set of devices (often referred to as nodes) connected by communication links. A node can be a computer, printer, or any other device capable of sending and/or receiving data generated by other nodes on the network.
The document discusses the physical structure of computer networks and their advantages and disadvantages. It defines a network as a set of connected devices that can send and receive data. Networks must meet performance, reliability, and security criteria. Performance depends on factors like the number of users and transmission medium. Reliability is measured by failure frequency and recovery time. Security issues include protecting data from unauthorized access and damage. There are two types of connections: point-to-point links that provide a dedicated connection between two devices, and multipoint links that allow more than two devices to share a single channel spatially or temporally.
The document discusses different topics related to data communication and computer networks. It defines data transmission modes as simplex, half-duplex, and full-duplex. It also discusses data signals, digital signals, analog signals, computer networks, the OSI model, TCP/IP model, broadband and baseband transmission, data modulation techniques, and sources of transmission impairment. The document serves to summarize key concepts from a class lecture on data communication.
Data communication involves the exchange of data between two devices via transmission medium such as wire cables. It is considered local communication if the devices are in close proximity like the same building.
The document then discusses the components of a data communication system including the message, sender, receiver, medium, protocols and characteristics of effective data communication.
It also covers topics like data transmission modes, data communication, digital modulation techniques, OSI model layers, TCP/IP model layers, and transmission impairments.
This document discusses data communications and some of its key components. It explains that data communications involves the exchange of data between two devices via some transmission medium. The five components of data communication are the message, sender, receiver, transmission medium, and protocols. It also discusses the four fundamental characteristics of effective data communication systems: delivery, accuracy, timeliness, and data flow, which can be simplex, half-duplex, or full-duplex. Finally, it distinguishes between point-to-point connections, which provide a dedicated link between two devices, and multipoint connections, which allow more than two devices to share a single link.
This document discusses data communications and some of its key components. It explains that data communications involves the exchange of data between two devices via some transmission medium. The five components of data communication are the message, sender, receiver, transmission medium, and protocols. It also outlines the four fundamental characteristics of an effective data communications system: delivery, accuracy, timeliness, and data flow (simplex, half-duplex, full-duplex). Finally, it discusses some important network criteria such as performance, reliability, and security.
A computer network connects autonomous devices like computers, printers, and other devices to exchange data. Nodes are connected by communication channels like copper wires, fiber optics, or wireless links. A distributed system builds a software system on top of a network so that the existence of multiple computers is transparent to the user. To be effective, networks must meet performance, reliability, and security criteria. Common network applications include electronic messaging, directory services, information services, electronic data interchange, and teleconferencing. Networks can be classified based on their topology like mesh, star, tree, bus, and ring configurations. Local area networks connect devices within a single building or campus.
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.
The document discusses data communications and networking concepts. It defines data communications as the exchange of data between two devices via transmission medium. It describes the five components of data communication as the message, sender, receiver, transmission medium, and protocols. It then discusses the four fundamental characteristics of effective data communication systems as delivery, accuracy, timeliness, and reliability. Finally, it differentiates between point-to-point connections which provide a dedicated link between two devices, and multipoint connections which allow more than two devices to share a single link.
This document discusses data communication and computer networks. It defines data communication, computer networks, and their key components. The five components of data communication are the message, sender, receiver, transmission medium, and protocols. Data can flow between devices in simplex, half-duplex, or full-duplex mode. Important network criteria include performance, reliability, and security. Networks can connect devices via either point-to-point or multipoint connections, with the difference being that point-to-point provides a dedicated link between two devices while multipoint allows more than two devices to share a single link.
This chapter provides an introduction to Computer networks and covers fundamental topics like data, information to the definition of communication and computer networks.
The document discusses different types of computer networks. It describes local area networks (LANs) as connecting hosts in a single office or building over short distances. Wide area networks (WANs) connect devices over longer distances, spanning towns, states or countries, and are typically run by telecommunications companies. Metropolitan area networks (MANs) provide connectivity over areas like a city or campus. LANs use switches to direct traffic to specific hosts, while WANs can be point-to-point connections between two devices or switched networks combining multiple point-to-point links.
A computer network connects independent computers to share resources. It consists of nodes, servers, and networking devices linked by transmission mediums like cables. Data communication is the exchange of data between devices via a transmission medium. It has five components: the message, sender, receiver, transmission medium, and protocols governing the communication. For effective data transmission, networks must meet criteria like performance, reliability, and security. Performance depends on factors like transit time. Reliability is measured by failure frequency and recovery time. Security involves protecting data access and integrity. Point-to-point links connect two devices exclusively, while multipoint links are shared between multiple devices.
Unit dsffffdgdigigjgkjxclvjxcvxcvxciofjgerioutsiosrut1.pptxgurjardeep68
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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.
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.
This document provides an overview of a lecture on data communication and computer networks. It defines key concepts like data communication, components of a communication system, transmission modes (simplex, half-duplex, full-duplex), characteristics of networks, types of networks (LAN, MAN, WAN), applications of networks, and a brief history of the Internet and World Wide Web. The document is presented as part of a lecture on introduction to computer networks.
GraphRAG for Life Science to increase LLM accuracyTomaz Bratanic
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GraphRAG for life science domain, where you retriever information from biomedical knowledge graphs using LLMs to increase the accuracy and performance of generated answers
A network is a set of devices (often referred to as nodes) connected by communication links. A node can be a computer, printer, or any other device capable of sending and/or receiving data generated by other nodes on the network.
“Computer network’’ to mean a collection of autonomous computers interconnected by a single technology. Two computers are said to be interconnected if they are able to exchange information.
The connection need not be via a copper wire; fiber optics, microwaves, infrared, and communication satellites can also be used.
Networks come in many sizes, shapes and forms, as we will see later. They are usually connected together to make larger networks, with the Internet being the most well- known example of a network of networks.
There is considerable confusion in the literature between a computer network and a distributed system. The key distinction is that in a distributed system, a collection of independent computers appears to its users as a single coherent system. Usually, it has a single model or paradigm that it presents to the users. Often a layer of software on top of the operating system, called middleware, is responsible for implementing this model. A well-known example of a distributed system is the World Wide Web. It runs on top of the Internet and presents a model in which everything looks like a document (Web page).
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.
This document provides an overview of data communication systems and their key components and concepts. It discusses the basic components of a data communication system including messages, senders, receivers, transmission medium, and protocols. It then describes various concepts such as line configuration (point-to-point and multipoint), network topologies (bus, star, ring, mesh), transmission modes (simplex, half-duplex, full-duplex), and modems. The document focuses on explaining these fundamental building blocks and concepts to understand how data is transmitted between devices.
This document provides an overview of data communications and computer networks. It discusses the need for computer communication over distances, defines data communication, and describes the key components and characteristics of data communication systems. It also covers various data representation methods, transmission media, network topologies, categories of networks including LANs, MANs and WANs, and the importance of protocols and standards in networking.
A network is a set of devices (often referred to as nodes) connected by communication links. A node can be a computer, printer, or any other device capable of sending and/or receiving data generated by other nodes on the network.
The document discusses the physical structure of computer networks and their advantages and disadvantages. It defines a network as a set of connected devices that can send and receive data. Networks must meet performance, reliability, and security criteria. Performance depends on factors like the number of users and transmission medium. Reliability is measured by failure frequency and recovery time. Security issues include protecting data from unauthorized access and damage. There are two types of connections: point-to-point links that provide a dedicated connection between two devices, and multipoint links that allow more than two devices to share a single channel spatially or temporally.
The document discusses different topics related to data communication and computer networks. It defines data transmission modes as simplex, half-duplex, and full-duplex. It also discusses data signals, digital signals, analog signals, computer networks, the OSI model, TCP/IP model, broadband and baseband transmission, data modulation techniques, and sources of transmission impairment. The document serves to summarize key concepts from a class lecture on data communication.
Data communication involves the exchange of data between two devices via transmission medium such as wire cables. It is considered local communication if the devices are in close proximity like the same building.
The document then discusses the components of a data communication system including the message, sender, receiver, medium, protocols and characteristics of effective data communication.
It also covers topics like data transmission modes, data communication, digital modulation techniques, OSI model layers, TCP/IP model layers, and transmission impairments.
This document discusses data communications and some of its key components. It explains that data communications involves the exchange of data between two devices via some transmission medium. The five components of data communication are the message, sender, receiver, transmission medium, and protocols. It also discusses the four fundamental characteristics of effective data communication systems: delivery, accuracy, timeliness, and data flow, which can be simplex, half-duplex, or full-duplex. Finally, it distinguishes between point-to-point connections, which provide a dedicated link between two devices, and multipoint connections, which allow more than two devices to share a single link.
This document discusses data communications and some of its key components. It explains that data communications involves the exchange of data between two devices via some transmission medium. The five components of data communication are the message, sender, receiver, transmission medium, and protocols. It also outlines the four fundamental characteristics of an effective data communications system: delivery, accuracy, timeliness, and data flow (simplex, half-duplex, full-duplex). Finally, it discusses some important network criteria such as performance, reliability, and security.
A computer network connects autonomous devices like computers, printers, and other devices to exchange data. Nodes are connected by communication channels like copper wires, fiber optics, or wireless links. A distributed system builds a software system on top of a network so that the existence of multiple computers is transparent to the user. To be effective, networks must meet performance, reliability, and security criteria. Common network applications include electronic messaging, directory services, information services, electronic data interchange, and teleconferencing. Networks can be classified based on their topology like mesh, star, tree, bus, and ring configurations. Local area networks connect devices within a single building or campus.
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.
The document discusses data communications and networking concepts. It defines data communications as the exchange of data between two devices via transmission medium. It describes the five components of data communication as the message, sender, receiver, transmission medium, and protocols. It then discusses the four fundamental characteristics of effective data communication systems as delivery, accuracy, timeliness, and reliability. Finally, it differentiates between point-to-point connections which provide a dedicated link between two devices, and multipoint connections which allow more than two devices to share a single link.
This document discusses data communication and computer networks. It defines data communication, computer networks, and their key components. The five components of data communication are the message, sender, receiver, transmission medium, and protocols. Data can flow between devices in simplex, half-duplex, or full-duplex mode. Important network criteria include performance, reliability, and security. Networks can connect devices via either point-to-point or multipoint connections, with the difference being that point-to-point provides a dedicated link between two devices while multipoint allows more than two devices to share a single link.
This chapter provides an introduction to Computer networks and covers fundamental topics like data, information to the definition of communication and computer networks.
The document discusses different types of computer networks. It describes local area networks (LANs) as connecting hosts in a single office or building over short distances. Wide area networks (WANs) connect devices over longer distances, spanning towns, states or countries, and are typically run by telecommunications companies. Metropolitan area networks (MANs) provide connectivity over areas like a city or campus. LANs use switches to direct traffic to specific hosts, while WANs can be point-to-point connections between two devices or switched networks combining multiple point-to-point links.
A computer network connects independent computers to share resources. It consists of nodes, servers, and networking devices linked by transmission mediums like cables. Data communication is the exchange of data between devices via a transmission medium. It has five components: the message, sender, receiver, transmission medium, and protocols governing the communication. For effective data transmission, networks must meet criteria like performance, reliability, and security. Performance depends on factors like transit time. Reliability is measured by failure frequency and recovery time. Security involves protecting data access and integrity. Point-to-point links connect two devices exclusively, while multipoint links are shared between multiple devices.
Unit dsffffdgdigigjgkjxclvjxcvxcvxciofjgerioutsiosrut1.pptxgurjardeep68
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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.
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.
This document provides an overview of a lecture on data communication and computer networks. It defines key concepts like data communication, components of a communication system, transmission modes (simplex, half-duplex, full-duplex), characteristics of networks, types of networks (LAN, MAN, WAN), applications of networks, and a brief history of the Internet and World Wide Web. The document is presented as part of a lecture on introduction to computer networks.
GraphRAG for Life Science to increase LLM accuracyTomaz Bratanic
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GraphRAG for life science domain, where you retriever information from biomedical knowledge graphs using LLMs to increase the accuracy and performance of generated answers
Your One-Stop Shop for Python Success: Top 10 US Python Development Providersakankshawande
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Simplify your search for a reliable Python development partner! This list presents the top 10 trusted US providers offering comprehensive Python development services, ensuring your project's success from conception to completion.
Main news related to the CCS TSI 2023 (2023/1695)Jakub Marek
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An English 🇬🇧 translation of a presentation to the speech I gave about the main changes brought by CCS TSI 2023 at the biggest Czech conference on Communications and signalling systems on Railways, which was held in Clarion Hotel Olomouc from 7th to 9th November 2023 (konferenceszt.cz). Attended by around 500 participants and 200 on-line followers.
The original Czech 🇨🇿 version of the presentation can be found here: https://www.slideshare.net/slideshow/hlavni-novinky-souvisejici-s-ccs-tsi-2023-2023-1695/269688092 .
The videorecording (in Czech) from the presentation is available here: https://youtu.be/WzjJWm4IyPk?si=SImb06tuXGb30BEH .
5th LF Energy Power Grid Model Meet-up SlidesDanBrown980551
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5th Power Grid Model Meet-up
It is with great pleasure that we extend to you an invitation to the 5th Power Grid Model Meet-up, scheduled for 6th June 2024. This event will adopt a hybrid format, allowing participants to join us either through an online Mircosoft Teams session or in person at TU/e located at Den Dolech 2, Eindhoven, Netherlands. The meet-up will be hosted by Eindhoven University of Technology (TU/e), a research university specializing in engineering science & technology.
Power Grid Model
The global energy transition is placing new and unprecedented demands on Distribution System Operators (DSOs). Alongside upgrades to grid capacity, processes such as digitization, capacity optimization, and congestion management are becoming vital for delivering reliable services.
Power Grid Model is an open source project from Linux Foundation Energy and provides a calculation engine that is increasingly essential for DSOs. It offers a standards-based foundation enabling real-time power systems analysis, simulations of electrical power grids, and sophisticated what-if analysis. In addition, it enables in-depth studies and analysis of the electrical power grid’s behavior and performance. This comprehensive model incorporates essential factors such as power generation capacity, electrical losses, voltage levels, power flows, and system stability.
Power Grid Model is currently being applied in a wide variety of use cases, including grid planning, expansion, reliability, and congestion studies. It can also help in analyzing the impact of renewable energy integration, assessing the effects of disturbances or faults, and developing strategies for grid control and optimization.
What to expect
For the upcoming meetup we are organizing, we have an exciting lineup of activities planned:
-Insightful presentations covering two practical applications of the Power Grid Model.
-An update on the latest advancements in Power Grid -Model technology during the first and second quarters of 2024.
-An interactive brainstorming session to discuss and propose new feature requests.
-An opportunity to connect with fellow Power Grid Model enthusiasts and users.
Digital Marketing Trends in 2024 | Guide for Staying AheadWask
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https://www.wask.co/ebooks/digital-marketing-trends-in-2024
Feeling lost in the digital marketing whirlwind of 2024? Technology is changing, consumer habits are evolving, and staying ahead of the curve feels like a never-ending pursuit. This e-book is your compass. Dive into actionable insights to handle the complexities of modern marketing. From hyper-personalization to the power of user-generated content, learn how to build long-term relationships with your audience and unlock the secrets to success in the ever-shifting digital landscape.
Monitoring and Managing Anomaly Detection on OpenShift.pdfTosin Akinosho
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Monitoring and Managing Anomaly Detection on OpenShift
Overview
Dive into the world of anomaly detection on edge devices with our comprehensive hands-on tutorial. This SlideShare presentation will guide you through the entire process, from data collection and model training to edge deployment and real-time monitoring. Perfect for those looking to implement robust anomaly detection systems on resource-constrained IoT/edge devices.
Key Topics Covered
1. Introduction to Anomaly Detection
- Understand the fundamentals of anomaly detection and its importance in identifying unusual behavior or failures in systems.
2. Understanding Edge (IoT)
- Learn about edge computing and IoT, and how they enable real-time data processing and decision-making at the source.
3. What is ArgoCD?
- Discover ArgoCD, a declarative, GitOps continuous delivery tool for Kubernetes, and its role in deploying applications on edge devices.
4. Deployment Using ArgoCD for Edge Devices
- Step-by-step guide on deploying anomaly detection models on edge devices using ArgoCD.
5. Introduction to Apache Kafka and S3
- Explore Apache Kafka for real-time data streaming and Amazon S3 for scalable storage solutions.
6. Viewing Kafka Messages in the Data Lake
- Learn how to view and analyze Kafka messages stored in a data lake for better insights.
7. What is Prometheus?
- Get to know Prometheus, an open-source monitoring and alerting toolkit, and its application in monitoring edge devices.
8. Monitoring Application Metrics with Prometheus
- Detailed instructions on setting up Prometheus to monitor the performance and health of your anomaly detection system.
9. What is Camel K?
- Introduction to Camel K, a lightweight integration framework built on Apache Camel, designed for Kubernetes.
10. Configuring Camel K Integrations for Data Pipelines
- Learn how to configure Camel K for seamless data pipeline integrations in your anomaly detection workflow.
11. What is a Jupyter Notebook?
- Overview of Jupyter Notebooks, an open-source web application for creating and sharing documents with live code, equations, visualizations, and narrative text.
12. Jupyter Notebooks with Code Examples
- Hands-on examples and code snippets in Jupyter Notebooks to help you implement and test anomaly detection models.
Ivanti’s Patch Tuesday breakdown goes beyond patching your applications and brings you the intelligence and guidance needed to prioritize where to focus your attention first. Catch early analysis on our Ivanti blog, then join industry expert Chris Goettl for the Patch Tuesday Webinar Event. There we’ll do a deep dive into each of the bulletins and give guidance on the risks associated with the newly-identified vulnerabilities.
Taking AI to the Next Level in Manufacturing.pdfssuserfac0301
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Read Taking AI to the Next Level in Manufacturing to gain insights on AI adoption in the manufacturing industry, such as:
1. How quickly AI is being implemented in manufacturing.
2. Which barriers stand in the way of AI adoption.
3. How data quality and governance form the backbone of AI.
4. Organizational processes and structures that may inhibit effective AI adoption.
6. Ideas and approaches to help build your organization's AI strategy.
“Temporal Event Neural Networks: A More Efficient Alternative to the Transfor...Edge AI and Vision Alliance
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For the full video of this presentation, please visit: https://www.edge-ai-vision.com/2024/06/temporal-event-neural-networks-a-more-efficient-alternative-to-the-transformer-a-presentation-from-brainchip/
Chris Jones, Director of Product Management at BrainChip , presents the “Temporal Event Neural Networks: A More Efficient Alternative to the Transformer” tutorial at the May 2024 Embedded Vision Summit.
The expansion of AI services necessitates enhanced computational capabilities on edge devices. Temporal Event Neural Networks (TENNs), developed by BrainChip, represent a novel and highly efficient state-space network. TENNs demonstrate exceptional proficiency in handling multi-dimensional streaming data, facilitating advancements in object detection, action recognition, speech enhancement and language model/sequence generation. Through the utilization of polynomial-based continuous convolutions, TENNs streamline models, expedite training processes and significantly diminish memory requirements, achieving notable reductions of up to 50x in parameters and 5,000x in energy consumption compared to prevailing methodologies like transformers.
Integration with BrainChip’s Akida neuromorphic hardware IP further enhances TENNs’ capabilities, enabling the realization of highly capable, portable and passively cooled edge devices. This presentation delves into the technical innovations underlying TENNs, presents real-world benchmarks, and elucidates how this cutting-edge approach is positioned to revolutionize edge AI across diverse applications.
HCL Notes und Domino Lizenzkostenreduzierung in der Welt von DLAUpanagenda
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Webinar Recording: https://www.panagenda.com/webinars/hcl-notes-und-domino-lizenzkostenreduzierung-in-der-welt-von-dlau/
DLAU und die Lizenzen nach dem CCB- und CCX-Modell sind für viele in der HCL-Community seit letztem Jahr ein heißes Thema. Als Notes- oder Domino-Kunde haben Sie vielleicht mit unerwartet hohen Benutzerzahlen und Lizenzgebühren zu kämpfen. Sie fragen sich vielleicht, wie diese neue Art der Lizenzierung funktioniert und welchen Nutzen sie Ihnen bringt. Vor allem wollen Sie sicherlich Ihr Budget einhalten und Kosten sparen, wo immer möglich. Das verstehen wir und wir möchten Ihnen dabei helfen!
Wir erklären Ihnen, wie Sie häufige Konfigurationsprobleme lösen können, die dazu führen können, dass mehr Benutzer gezählt werden als nötig, und wie Sie überflüssige oder ungenutzte Konten identifizieren und entfernen können, um Geld zu sparen. Es gibt auch einige Ansätze, die zu unnötigen Ausgaben führen können, z. B. wenn ein Personendokument anstelle eines Mail-Ins für geteilte Mailboxen verwendet wird. Wir zeigen Ihnen solche Fälle und deren Lösungen. Und natürlich erklären wir Ihnen das neue Lizenzmodell.
Nehmen Sie an diesem Webinar teil, bei dem HCL-Ambassador Marc Thomas und Gastredner Franz Walder Ihnen diese neue Welt näherbringen. Es vermittelt Ihnen die Tools und das Know-how, um den Überblick zu bewahren. Sie werden in der Lage sein, Ihre Kosten durch eine optimierte Domino-Konfiguration zu reduzieren und auch in Zukunft gering zu halten.
Diese Themen werden behandelt
- Reduzierung der Lizenzkosten durch Auffinden und Beheben von Fehlkonfigurationen und ĂĽberflĂĽssigen Konten
- Wie funktionieren CCB- und CCX-Lizenzen wirklich?
- Verstehen des DLAU-Tools und wie man es am besten nutzt
- Tipps für häufige Problembereiche, wie z. B. Team-Postfächer, Funktions-/Testbenutzer usw.
- Praxisbeispiele und Best Practices zum sofortigen Umsetzen
Introduction of Cybersecurity with OSS at Code Europe 2024Hiroshi SHIBATA
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I develop the Ruby programming language, RubyGems, and Bundler, which are package managers for Ruby. Today, I will introduce how to enhance the security of your application using open-source software (OSS) examples from Ruby and RubyGems.
The first topic is CVE (Common Vulnerabilities and Exposures). I have published CVEs many times. But what exactly is a CVE? I'll provide a basic understanding of CVEs and explain how to detect and handle vulnerabilities in OSS.
Next, let's discuss package managers. Package managers play a critical role in the OSS ecosystem. I'll explain how to manage library dependencies in your application.
I'll share insights into how the Ruby and RubyGems core team works to keep our ecosystem safe. By the end of this talk, you'll have a better understanding of how to safeguard your code.
Building Production Ready Search Pipelines with Spark and MilvusZilliz
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Spark is the widely used ETL tool for processing, indexing and ingesting data to serving stack for search. Milvus is the production-ready open-source vector database. In this talk we will show how to use Spark to process unstructured data to extract vector representations, and push the vectors to Milvus vector database for search serving.
What is an RPA CoE? Session 1 – CoE VisionDianaGray10
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In the first session, we will review the organization's vision and how this has an impact on the COE Structure.
Topics covered:
• The role of a steering committee
• How do the organization’s priorities determine CoE Structure?
Speaker:
Chris Bolin, Senior Intelligent Automation Architect Anika Systems
Driving Business Innovation: Latest Generative AI Advancements & Success StorySafe Software
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Are you ready to revolutionize how you handle data? Join us for a webinar where we’ll bring you up to speed with the latest advancements in Generative AI technology and discover how leveraging FME with tools from giants like Google Gemini, Amazon, and Microsoft OpenAI can supercharge your workflow efficiency.
During the hour, we’ll take you through:
Guest Speaker Segment with Hannah Barrington: Dive into the world of dynamic real estate marketing with Hannah, the Marketing Manager at Workspace Group. Hear firsthand how their team generates engaging descriptions for thousands of office units by integrating diverse data sources—from PDF floorplans to web pages—using FME transformers, like OpenAIVisionConnector and AnthropicVisionConnector. This use case will show you how GenAI can streamline content creation for marketing across the board.
Ollama Use Case: Learn how Scenario Specialist Dmitri Bagh has utilized Ollama within FME to input data, create custom models, and enhance security protocols. This segment will include demos to illustrate the full capabilities of FME in AI-driven processes.
Custom AI Models: Discover how to leverage FME to build personalized AI models using your data. Whether it’s populating a model with local data for added security or integrating public AI tools, find out how FME facilitates a versatile and secure approach to AI.
We’ll wrap up with a live Q&A session where you can engage with our experts on your specific use cases, and learn more about optimizing your data workflows with AI.
This webinar is ideal for professionals seeking to harness the power of AI within their data management systems while ensuring high levels of customization and security. Whether you're a novice or an expert, gain actionable insights and strategies to elevate your data processes. Join us to see how FME and AI can revolutionize how you work with data!
Digital Banking in the Cloud: How Citizens Bank Unlocked Their MainframePrecisely
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Inconsistent user experience and siloed data, high costs, and changing customer expectations – Citizens Bank was experiencing these challenges while it was attempting to deliver a superior digital banking experience for its clients. Its core banking applications run on the mainframe and Citizens was using legacy utilities to get the critical mainframe data to feed customer-facing channels, like call centers, web, and mobile. Ultimately, this led to higher operating costs (MIPS), delayed response times, and longer time to market.
Ever-changing customer expectations demand more modern digital experiences, and the bank needed to find a solution that could provide real-time data to its customer channels with low latency and operating costs. Join this session to learn how Citizens is leveraging Precisely to replicate mainframe data to its customer channels and deliver on their “modern digital bank” experiences.
Programming Foundation Models with DSPy - Meetup SlidesZilliz
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Prompting language models is hard, while programming language models is easy. In this talk, I will discuss the state-of-the-art framework DSPy for programming foundation models with its powerful optimizers and runtime constraint system.
[OReilly Superstream] Occupy the Space: A grassroots guide to engineering (an...Jason Yip
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The typical problem in product engineering is not bad strategy, so much as “no strategy”. This leads to confusion, lack of motivation, and incoherent action. The next time you look for a strategy and find an empty space, instead of waiting for it to be filled, I will show you how to fill it in yourself. If you’re wrong, it forces a correction. If you’re right, it helps create focus. I’ll share how I’ve approached this in the past, both what works and lessons for what didn’t work so well.
[OReilly Superstream] Occupy the Space: A grassroots guide to engineering (an...
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Unit-1.docx
1. Data Communication and Computer Networks – BIM 2nd Semester
By Lec. Pratik Chand, Morgan Int’l College Page 1
Unit 1: Introduction to data communication
Data communication refers to the exchange of data between a source and a receiver
via form of transmission media such as a wire cable. For data communications to
occur, the communicating devices must be part of a communication system made
up of a combination of hardware (physical equipment) and software (programs).
The effectiveness of a data communications system depends on four fundamental
characteristics: delivery, accuracy, timeliness, and jitter.
Delivery: The system must deliver data to the correct destination. Data must be
received by the intended device or user and only by that device or user.
Accuracy: The system must deliver the data accurately. Data that have been altered
in transmission and left uncorrected are unusable.
Timeliness: The system must deliver data in a timely manner. Data delivered late
are useless. In the case of video and audio, timely delivery means delivering data
as they are produced, in the same order that they are produced, and without
significant delay. This kind of delivery is called real-time transmission.
Jitter: Jitter refers to the variation in the packet arrival time. It is the uneven delay
in the delivery of audio or video packets.
A Basic Communication Model:
A data communications system has five components.
Fig: Data communication model
2. Data Communication and Computer Networks – BIM 2nd Semester
By Lec. Pratik Chand, Morgan Int’l College Page 2
Message: The message is the information (data) to be communicated. Popular
forms of information include text, numbers, pictures, audio, and video.
Sender: The sender is the device that sends the data message. It can be a computer,
workstation, telephone handset, video camera, and so on.
Receiver: The receiver is the device that receives the message. It can be a
computer, workstation, telephone handset, television, and so on.
Transmission medium: The transmission medium is the physical path by which a
message travels from sender to receiver. Some examples of transmission media
include twisted-pair wire, coaxial cable, fiber-optic cable, and radio waves.
Protocol: A protocol is a set of rules that govern data communications. It
represents an agreement between the communicating devices.
Data Transmission Modes
Communication between two devices can be simplex, half-duplex, or full-duplex.
Simplex:
In simplex mode, the communication is unidirectional, as on a one-way street.
Only one of the two devices on a link can transmit; the other can only receive.
Keyboards and traditional monitors are examples of simplex devices. The
keyboard can only introduce input; the monitor can only accept output. The
simplex mode can use the entire capacity of the channel to send data in one
direction.
3. Data Communication and Computer Networks – BIM 2nd Semester
By Lec. Pratik Chand, Morgan Int’l College Page 3
Half-Duplex:
In half-duplex mode, each station can both transmit and receive, but not at the
same time. When one device is sending, the other can only receive, and vice versa.
In a half-duplex transmission, the entire capacity of a channel is taken over by
whichever of the two devices is transmitting at the time. Walkie-talkies and CB
(citizens band) radios are both half-duplex systems. The half-duplex mode is used
in cases where there is no need for communication in both directions at the same
time; the entire capacity of the channel can be utilized for each direction.
Full-Duplex:
In full-duplex both stations can transmit and receive simultaneously. The full-
duplex mode is like a two-way street with traffic flowing in both directions at the
same time. In full-duplex mode, signals going in one direction share the capacity of
the link: with signals going in the other direction. One common example of full-
duplex communication is the telephone network. When two people are
communicating by a telephone line, both can talk and listen at the same time. The
full-duplex mode is used when communication in both directions is required all the
time. The capacity of the channel, however, must be divided between the two
directions.
4. Data Communication and Computer Networks – BIM 2nd Semester
By Lec. Pratik Chand, Morgan Int’l College Page 4
Data Communication Networking:
Data communications refers to the transmission of digital data between two or
more computers and a computer network or data network is a telecommunications
network that allows computers to exchange data. The physical connection between
networked computing devices is established using either cable media or wireless
media. The best-known computer network is the Internet.
A network is a set of devices (often referred to as nodes) connected by
communication links. A node can be a computer, printer, or any other device
capable of sending and/or receiving data generated by other nodes on the network.
Network Criteria
A network must be able to meet a certain number of criteria. The most important of
these are performance, reliability, and security.
Performance: Performance can be measured in many ways, including transit time
and response time. Transit time is the amount of time required for a message to
travel from one device to another. Response time is the elapsed time between an
inquiry and a response. The performance of a network depends on a number of
factors, including the number of users, the type of transmission medium, the
capabilities of the connected hardware, and the efficiency of the software.
Reliability: Network reliability is measured by the frequency of failure, the time it
takes a link to recover from a failure, and the network's robustness in a catastrophe.
Security: Network security issues include protecting data from unauthorized
access, protecting data from damage and development, and implementing policies
and procedures for recovery from breaches and data losses.
Physical Structures:
A network is two or more devices connected through links. A link is a
communications pathway that transfers data from one device to another. There are
two possible types of connections: point-to-point and multipoint.
5. Data Communication and Computer Networks – BIM 2nd Semester
By Lec. Pratik Chand, Morgan Int’l College Page 5
Point-to-Point: A point-to-point connection provides a dedicated link between two
devices. The entire capacity of the link is reserved for transmission between those
two devices. Most point-to-point connections use an actual length of wire or cable
to connect the two ends, but other options, such as microwave or satellite links, are
also possible. When you change television channels by infrared remote control,
you are establishing a point-to-point connection between the remote control and
the television's control system.
Multipoint: A multipoint (also called multi-drop) connection is one in which more
than two specific devices share a single link. In a multipoint environment, the
capacity of the channel is shared, either spatially or temporally. If several devices
can use the link simultaneously, it is a spatially shared connection. If users must
take turns, it is a timeshared connection.
Physical Topology:
The term physical topology refers to the way in which a network is laid out
physically. One or more devices connect to a link; two or more links form a
topology. The topology of a network is the geometric representation of the
relationship of all the links and linking devices (usually called nodes) to one
another. There are four basic topologies possible: mesh, star, bus, and ring.
6. Data Communication and Computer Networks – BIM 2nd Semester
By Lec. Pratik Chand, Morgan Int’l College Page 6
Mesh Topology:
In a mesh topology, every device has a dedicated point-to-point link to every other
device. The term dedicated means that the link carries traffic only between the two
devices it connects. To find the number of physical links in a fully connected mesh
network with n nodes, we first consider that each node must be connected to every
other node. Node 1 must be connected to n – 1 nodes, node 2 must be connected to
n – 1 node, and finally node n must be connected to n - 1 nodes. We need n (n - 1)
physical links. However, If each physical link allows communication in both
directions (duplex mode), we can divide the number of links by 2. In other words,
we can say that in a mesh topology, we need n (n -1) /2 duplex-mode links. To
accommodate that many links, every device on the network must have n – 1
input/output ports to be connected to the other n - 1 stations.
7. Data Communication and Computer Networks – BIM 2nd Semester
By Lec. Pratik Chand, Morgan Int’l College Page 7
Advantages:
ď‚· The use of dedicated links guarantees that each connection can carry its own
data load, thus eliminating the traffic problems that can occur when links
must be shared by multiple devices.
ď‚· A mesh topology is robust. If one link becomes unusable, it does not
incapacitate the entire system.
ď‚· There is the advantage of privacy or security. When every message travel
along a dedicated line, only the intended recipient sees it. Physical
boundaries prevent other users from gaining access to messages.
ď‚· Point-to-point links make fault identification and fault isolation easy. Traffic
can be routed to avoid links with suspected problems. This facility enables
the network manager to discover the precise location of the fault and aids in
finding its cause and solution.
Disadvantages:
ď‚· Disadvantage of a mesh are related to the amount of cabling because every
device must be connected to every other device.
ď‚· Installation and reconnection are difficult.
8. Data Communication and Computer Networks – BIM 2nd Semester
By Lec. Pratik Chand, Morgan Int’l College Page 8
ď‚· The sheer bulk of the wiring can be greater than the available space (in
walls, ceilings, or floors) can accommodate.
ď‚· The hardware required to connect each link (I/O ports and cable) can be
prohibitively expensive.
Star Topology:
In a star topology, each device has a dedicated point-to-point link only to a central
controller, usually called a hub. The devices are not directly linked to one another.
Unlike a mesh topology, a star topology does not allow direct traffic between
devices. The controller acts as an exchange: If one device wants to send data to
another, it sends the data to the controller, which then relays the data to the other
connected device.
Advantages:
ď‚· A star topology is less expensive than a mesh topology. In a star, each
device needs only one link and one I/O port to connect it to any number of
others.
ď‚· Easy to install and reconfigure.
ď‚· Far less cabling needs to be housed, and additions, moves, and deletions
involve only one connection: between that device and the hub.
9. Data Communication and Computer Networks – BIM 2nd Semester
By Lec. Pratik Chand, Morgan Int’l College Page 9
ď‚· Other advantage include robustness. If one link fails, only that link is
affected. All other links remain active. This factor also lends itself to easy
fault identification and fault isolation. As long as the hub is working, it can
be used to monitor link problems and bypass defective links.
Disadvantages:
ď‚· Dependency of the whole topology on one single point, the hub.
ď‚· If the hub goes down, the whole system is dead.
ď‚· Although a star requires far less cable than a mesh, each node must be linked
to a central hub. For this reason, often more cabling is required in a star than
in some other topologies (such as ring or bus).
Bus Topology:
A bus topology is multipoint. One long cable acts as a backbone to link all the
devices in a network. Nodes are connected to the bus cable by drop lines and taps.
A drop line is a connection running between the device and the main cable. A tap
is a connector that either splices into the main cable or punctures the sheathing of a
cable to create a contact with the metallic core. As a signal travels along the
backbone, some of its energy is transformed into heat. Therefore, it becomes
weaker and weaker as it travels farther and farther. For this reason, there is a limit
on the number of taps a bus can support and on the distance between those taps.
10. Data Communication and Computer Networks – BIM 2nd Semester
By Lec. Pratik Chand, Morgan Int’l College Page 10
Advantages:
ď‚· Advantages of a bus topology include ease of installation.
ď‚· Backbone cable can be laid along the most efficient path, then, connected to
the nodes by drop lines of various lengths.
ď‚· A bus uses less cabling than mesh or star topologies.
ď‚· In a star, for example, four network devices in the same room require four
lengths of cable reaching all the way to the hub. In a bus, this redundancy is
eliminated.
ď‚· Only the backbone cable stretches through the entire facility. Each drop line
has to reach only as far as the nearest point on the backbone.
Disadvantages:
ď‚· Difficult reconnection and fault isolation.
ď‚· A bus is usually designed to be optimally efficient at installation.
ď‚· It can therefore be difficult to add new devices. Signal reflection at the taps
can cause degradation in quality.
ď‚· This degradation can be controlled by limiting the number and spacing of
devices connected to a given length of cable.
ď‚· Adding new devices may therefore require modification or replacement of
the backbone.
ď‚· A fault or break in the bus cable stops all transmission, even between
devices on the same side of the problem. The damaged area reflects signals
back in the direction of origin, creating noise in both directions.
Ring Topology:
In a ring topology, each device has a dedicated point-to-point connection with only
the two devices on either side of it. A signal is passed along the ring in one
direction, from device to device, until it reaches its destination. Each device in the
ring incorporates a repeater. When a device receives a signal intended for another
device, its repeater regenerates the bits and passes them along.
11. Data Communication and Computer Networks – BIM 2nd Semester
By Lec. Pratik Chand, Morgan Int’l College Page 11
Advantages:
ď‚· A ring is relatively easy to install and reconfigure. Each device is linked to
only its immediate neighbors (either physically or logically).
ď‚· To add or delete a device requires changing only two connections.
ď‚· The only constraints are media and traffic considerations (maximum ring
length and number of devices).
ď‚· Fault isolation is simplified. Generally, in a ring, a signal is circulating at all
times. If one device does not receive a signal within a specified period, it can
issue an alarm. The alarm alerts the network operator to the problem and its
location.
Disadvantages:
ď‚· Unidirectional traffic can be a disadvantage. In a simple ring, a break in the
ring (such as a disabled station) can disable the entire network. This
weakness can be solved by using a dual ring or a switch capable of closing
off the break.
ď‚· Ring topology was prevalent when IBM introduced its local-area network
Token Ring. Today, the need for higher-speed LANs has made this topology
less popular.
12. Data Communication and Computer Networks – BIM 2nd Semester
By Lec. Pratik Chand, Morgan Int’l College Page 12
Network Categories
Local Area Networks (LAN):
Local area networks, generally called LANs, are privately-owned networks within
a single building or campus of up to a few kilometers in size. They are widely used
to connect personal computers and workstations in company offices and
organizations to share resources (e.g., printers) and exchange information. LANs
are distinguished from other kinds of networks by three characteristics:
ď‚· Their size,
ď‚· Their transmission technology
ď‚· Their topology.
LANs are restricted in size, which means that the worst-case transmission time is
bounded and known in advance. Knowing this bound makes it possible to use
certain kinds of designs that would not otherwise be possible. It also simplifies
network management. Traditional LANs run at speeds of 10 Mbps to 100 Mbps,
have low delay (microseconds or nanoseconds), and make very few errors. Newer
LANs operate at up to 10 Gbps.
Fig: Local Area Network.
13. Data Communication and Computer Networks – BIM 2nd Semester
By Lec. Pratik Chand, Morgan Int’l College Page 13
Characteristics of LAN:
ď‚· LANs are private networks, not subject to external control
ď‚· Simple and better performance
ď‚· Work in a restricted geographical area
Advantages:
ď‚· Resource sharing
ď‚· Software applications sharing
ď‚· Easy and Cheap communication
ď‚· Data Security
ď‚· Internet sharing
Disadvantages
ď‚· Restricted to local area
Metropolitan Area Network (MAN):
A metropolitan area network, or MAN, covers a city. A MAN is a computer
network that interconnects users with computer resources in a geographical area or
region larger than that covered by a LAN. It can be an interconnection between
several LANs by bridging them with backbone lines.
14. Data Communication and Computer Networks – BIM 2nd Semester
By Lec. Pratik Chand, Morgan Int’l College Page 14
Fig: Metropolitan Area Network
Characteristics:
ď‚· Generally, covers towns and cities (up to 50km)
ď‚· Transmission medium used for MAN is optical fiber, coaxial cable etc.
ď‚· Data rates adequate for distributed computing applications
Advantages:
ď‚· Extremely efficient and provide fast communication via high-speed carriers,
such as fiber optic cables
ď‚· Good backbone for larger networks and provides greater access to WAN
Disadvantages
ď‚· Complex, more cabling required and expensive
The best-known example of a MAN is the cable television network available in
many cities. This system grew from earlier community antenna systems used in
areas with poor over-the-air television reception. In these early systems, a large
antenna was placed on top of a nearby hill and signal was then piped to the
subscribers' houses. At first, these were locally-designed, ad hoc systems. Then
companies began jumping into the business, getting contracts from city
governments to wire up an entire city. The next step was television programming
and even entire channels designed for cable only. Often these channels were highly
specialized, such as all news, all sports, all cooking, all gardening, and so on. But
from their inception until the late 1990s, they were intended for television
reception only. Cable television is not the only MAN. Recent developments in
high-speed wireless Internet access resulted in another MAN, which has been
standardized as IEEE 802.16.
Wide Area Network (WAN):
A wide area network, or WAN, spans a large geographical area, often a country or
continent. It contains a collection of machines intended for running user (i.e.,
application) programs. These machines are called as hosts. The hosts are connected
15. Data Communication and Computer Networks – BIM 2nd Semester
By Lec. Pratik Chand, Morgan Int’l College Page 15
by a communication subnet, or just subnet for short. The hosts are owned by the
customers (e.g., people's personal computers), whereas the communication subnet
is typically owned and operated by a telephone company or Internet service
provider (ISP). The job of the subnet is to carry messages from host to host, just as
the telephone system carries words from speaker to listener. Separation of the pure
communication aspects of the network (the subnet) from the application aspects
(the hosts), greatly simplifies the complete network design. In most wide area
networks, the subnet consists of two distinct components: transmission lines and
switching elements. Transmission lines move bits between machines. They can be
made of copper wire, optical fiber, or even radio links. WANs are typically used to
connect two or more LANs or MANs which are located relatively very far from
each other.
Fig: Wide Area Network
Characteristics
ď‚· Covers large distances (states, countries, continents)
ď‚· Communication medium used are satellite, public telephone networks which
are connected by routers
16. Data Communication and Computer Networks – BIM 2nd Semester
By Lec. Pratik Chand, Morgan Int’l College Page 16
Advantages
ď‚· Covers large geographical area
ď‚· Shares software and resources with connecting workstations
ď‚· Information can be exchanged to anyone else worldwide in the network
Disadvantages
ď‚· Data security
ď‚· Network is very complex and management is difficult
ď‚· As size increases, the networks becomes more expensive
End of Unit-1