Data communication and networking involves the transfer of data between a source and receiver. There are different types of data (analog and digital) and various methods for data to flow (simplex, half-duplex, and full-duplex). Modems allow computers to transmit digital data over analog networks like telephone lines by modulating and demodulating signals. Common network topologies include bus, star, ring and tree configurations using different transmission media like twisted pair, coaxial or fiber optic cabling. The OSI model defines a framework for network communication using seven stacked layers.
This document provides an introduction to data communication and networking. It discusses analog and digital data, data communication, data flow including simplex, half-duplex and full-duplex, and modems. It also covers local area networks, metropolitan area networks, wide area networks, network topologies including linear bus, star, tree and others. Finally, it discusses the OSI model and considerations for data communication networks including performance, consistency, reliability and recovery.
What is a network?
Need for networking
Components of Network
Types of Network
Evolution of Networking
Communication media
Data Communication Terminologies
Switching Techniques
Digital and Analog Transmission
Network Topology
Network Devices
Communication Protocols
Wireless/Mobile Computing
Course Code: CS-301
Course Title: Introduction to Computing.
Degree: BS (SE, CS, BIO)
Contents of this chapter:
Basic information about computer networks, types of computer networks. Other contents include:
1. List four major benefits of connecting computers to form a network.
2. Define the terms LAN, WAN, and MAN.
3. List the three types of networks.
4. Name the three physical topologies used to build networks.
This document provides an overview of key concepts in computer networks and communication. It defines what a network is, discusses the need for networking and sharing of resources, and outlines the evolution of early networks like ARPANET and NSFNET into the modern Internet. It also covers network topologies, transmission media, switching techniques, common network devices, and communication protocols.
Computer networks allow interconnected computers and devices to share information and resources. They transmit digital data through physical transmission mediums like cables or wirelessly. Protocols define communication standards to minimize errors. Popular uses of networks include e-business, online education, and remote communication, which have benefited society through increased access and lower costs.
Basics of data communication and computer networking (262 kb)IMRAN KHAN
The document discusses the basics of data communication and computer networking. It introduces data communication as the process of transporting data from one point to another using networks. Networks are communication systems designed to convey information from a point of origin to a point of destination. The key components of a data communication system include a transmitter that sends the message, a receiver that receives the message, a communication medium that carries the message, the message itself, and a communication protocol. Computer networks allow for the sharing of resources between connected computers.
This document provides an overview of computer networks, including definitions of common network types (LAN, MAN, WAN), protocols (TCP, IP), internet components, connection types, cabling technologies (coaxial, Ethernet, fiber optic), and wireless standards (Bluetooth, infrared, Wi-Fi). It describes the basic needs for networking like sharing hardware/software and centralized administration. It also outlines common network topologies like star, bus, and ring configurations and the key characteristics of each.
A network connects computers and devices together through communication devices and transmission media. A local area network (LAN) connects devices in a limited area like a home or office building. Networks provide advantages like speed, cost savings, security, resource sharing, email and centralized software management. However, networks also have disadvantages such as high setup costs, single point of failures, virus spreading and performance declines with increased traffic. Common network architectures include client-server, where servers provide services to clients, and peer-to-peer where devices connect directly to each other. Common network topologies are bus, ring and star, with stars being popular due to their ease of installation and maintenance. Standards like Ethernet, WiFi, Bluetooth, TCP/IP and
This document provides an introduction to data communication and networking. It discusses analog and digital data, data communication, data flow including simplex, half-duplex and full-duplex, and modems. It also covers local area networks, metropolitan area networks, wide area networks, network topologies including linear bus, star, tree and others. Finally, it discusses the OSI model and considerations for data communication networks including performance, consistency, reliability and recovery.
What is a network?
Need for networking
Components of Network
Types of Network
Evolution of Networking
Communication media
Data Communication Terminologies
Switching Techniques
Digital and Analog Transmission
Network Topology
Network Devices
Communication Protocols
Wireless/Mobile Computing
Course Code: CS-301
Course Title: Introduction to Computing.
Degree: BS (SE, CS, BIO)
Contents of this chapter:
Basic information about computer networks, types of computer networks. Other contents include:
1. List four major benefits of connecting computers to form a network.
2. Define the terms LAN, WAN, and MAN.
3. List the three types of networks.
4. Name the three physical topologies used to build networks.
This document provides an overview of key concepts in computer networks and communication. It defines what a network is, discusses the need for networking and sharing of resources, and outlines the evolution of early networks like ARPANET and NSFNET into the modern Internet. It also covers network topologies, transmission media, switching techniques, common network devices, and communication protocols.
Computer networks allow interconnected computers and devices to share information and resources. They transmit digital data through physical transmission mediums like cables or wirelessly. Protocols define communication standards to minimize errors. Popular uses of networks include e-business, online education, and remote communication, which have benefited society through increased access and lower costs.
Basics of data communication and computer networking (262 kb)IMRAN KHAN
The document discusses the basics of data communication and computer networking. It introduces data communication as the process of transporting data from one point to another using networks. Networks are communication systems designed to convey information from a point of origin to a point of destination. The key components of a data communication system include a transmitter that sends the message, a receiver that receives the message, a communication medium that carries the message, the message itself, and a communication protocol. Computer networks allow for the sharing of resources between connected computers.
This document provides an overview of computer networks, including definitions of common network types (LAN, MAN, WAN), protocols (TCP, IP), internet components, connection types, cabling technologies (coaxial, Ethernet, fiber optic), and wireless standards (Bluetooth, infrared, Wi-Fi). It describes the basic needs for networking like sharing hardware/software and centralized administration. It also outlines common network topologies like star, bus, and ring configurations and the key characteristics of each.
A network connects computers and devices together through communication devices and transmission media. A local area network (LAN) connects devices in a limited area like a home or office building. Networks provide advantages like speed, cost savings, security, resource sharing, email and centralized software management. However, networks also have disadvantages such as high setup costs, single point of failures, virus spreading and performance declines with increased traffic. Common network architectures include client-server, where servers provide services to clients, and peer-to-peer where devices connect directly to each other. Common network topologies are bus, ring and star, with stars being popular due to their ease of installation and maintenance. Standards like Ethernet, WiFi, Bluetooth, TCP/IP and
Academic course on Computer Network Chapter -1 for BCA, Tribhuwan University
** Applicable for other courses as well
Includes the Basic of Computer Network, Topologies, Types of Network
A network connects two or more computers. The main types are local area networks (LANs), which span a small area like a building, and wide area networks (WANs), which connect computers over a large geographical area through multiple LANs. Networks can use physical cables like twisted pair or wireless connections. They are categorized based on their topology, protocols, and architecture. Key networking hardware and software allow computers to communicate and share resources over the network.
An interconnected collection of autonomous computers is called a computer network. Networks allow computers to share resources like hardware, software, databases, and communicate with each other. The first network was ARPANET in 1969 which connected universities and defense organizations in the US. Later networks like NSFnet and the Internet improved capacity and connectivity. A network uses nodes, servers, network interface units, and types of networks can be LANs, MANs, or WANs depending on geographical reach. Networking evolved to improve sharing, reliability, and reduce costs.
In data communication,
Transmission media is a pathway that carries the information from sender to receiver.
We use different types of cables or waves to transmit data.
Data is transmitted normally through electrical or electromagnetic signals.
Synchronous optical networking (SONET) is a standardized digital communication protocol that is used to transmit a large volume of data over relatively long distances using a fiber optic medium. With SONET, multiple digital data streams are transferred at the same time over optical fiber using LEDs and laser beams.
This document provides an overview of advanced networking concepts. It begins with learning objectives around data communication, network devices, protocols, topologies and network types. It then defines key networking components like switches, routers, and firewalls. It discusses different network topologies, media like Ethernet and wireless, and various network types including LAN, WAN, SAN and more. The document is intended to help readers understand fundamental networking concepts.
A local area network (LAN) connects computers and devices within a limited geographic area like an office or building. Devices on a LAN are connected through cables, wireless links, or infrared beams and share resources like printers and files. Common types of LANs include Ethernet, Token Ring, Token Bus, and Fiber Distributed Data Interface (FDDI) networks. A LAN allows resources to be shared, communication to be convenient, data to be centralized, and internet access to be shared among connected devices. However, LANs also have costs to implement and maintain and raise security and privacy concerns.
MIS-Presentation management information systems.pptxMdSabujHossen2
The document discusses various topics related to data communication and computer networks. It provides details about the group members working on the project. It then discusses basic elements of a communication system including a sender, medium, and receiver. It explains different data transmission models such as simplex, half-duplex, and full-duplex. It also discusses data transmission speed and different categories based on bandwidth. The document covers additional topics such as data transmission media, digital and analog transmission, network topologies, types of networks, roles of communication protocols, wireless technologies and issues, elements of internet search engines, and uses of the internet.
In this slide I explain What is Data Communication and Networks and its Applications And also explain Physical Topology, Types of Physical Topologies, Categories of Networks that is LAN, WAN, MAN and coverage of Networks etc.
Program/Course : Computer System Servicing NC II
Unit of Competency : Set-up Computer Networks
Module : Install Network Cables
Learning Outcome 01: Installing Network Cables
for full compilation just visit my website.
http://computersystemsolution.com/
A computer network is a set of connected computers. Computers on a network are called nodes. The connection between computers can be done via cabling, most commonly the Ethernet cable, or wireless through radio waves. Connected computers can share resources, like access to the Internet, printers, file servers, and others. A network is a multipurpose connection, which allows a single computer to do more.
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@ Kindly Follow my Instagram Page to discuss about your mental health problems-
-----> https://instagram.com/mentality_streak?utm_medium=copy_link
@ Appreciate my work:
-----> behance.net/burhanahmed1
Thank-you !
The document discusses computer networks and communication. It begins with an introduction to how computer networks were developed in the 1960s to enable fast and real-time data transfer for scientific research. It then defines what a network is and discusses various types of networks including LANs, WANs, MANs, peer-to-peer networks, and examples like Ethernet. It also covers network topologies, the ISO-OSI reference model, and considerations for networking like cost, training, security and more.
This document provides an introduction to computer networks. It begins with definitions of common network types including local area networks (LANs), metropolitan area networks (MANs), and wide area networks (WANs). It describes common network topologies like bus, star, ring, tree, and mesh. It also discusses network components such as physical media, interconnecting devices, computers, networking software, and applications. The document provides examples of networking applications and protocols like TCP/IP. It introduces concepts like packets, routers, and packet switching. It also discusses open systems, internet connections, network addressing, and the domain name system.
This document provides information about different types of computer networks and networking components. It defines and describes various network topologies including bus, ring, mesh, star, tree, and hybrid topologies. It also discusses different types of networks such as personal area networks, local area networks, wireless local area networks, campus area networks, metropolitan area networks, wide area networks, storage area networks, and virtual private networks. Furthermore, it covers the four main types of network cabling, common network connectors, and basic network components including end points, network interface cards, repeaters, hubs, switches, and routers.
This document provides an introduction to computer networks, including definitions of key network concepts and components. It discusses the basic applications and purposes of networks, as well as what can be found on networks including hosts, terminals, clients, and servers. It also describes common networking devices like NICs, modems, hubs, switches, and routers. Additionally, it covers network topologies, transmission modes, and the different categories of networks including LANs, MANs, and WANs.
This document discusses telecommunications and computer networks. It defines communication, telecommunications, and data communication. The objectives of communication networks are to offer timely information exchange, reduce effort and costs, and support improved management. Networks use simplex, half-duplex, and full-duplex transmission modes. Analog transmission sends continuous signals while digital transmission sends discrete values. Asynchronous transmission sends characters independently while synchronous transmission sends data in blocks. The telecommunication network model includes end user terminals, telecommunication processors, channels, computers, software, and various components that connect networks. [/SUMMARY]
This document discusses LAN and WAN network architectures. It covers key topics such as:
- LANs are privately owned networks that connect devices within a single building, while WANs provide long-distance transmission across large geographic areas.
- Common LAN technologies include Ethernet, Token Ring, and FDDI, with Ethernet being the most widely used standard.
- WANs connect multiple LANs and use transmission technologies like leased lines, circuits switching, and packet switching to transmit data over large distances.
- The document provides an overview of LAN and WAN components, protocols, topologies and transmission methods.
This document provides an introduction to computer networks presented by Ram nivas sonkar. It begins with defining what a computer network is and discusses the key components and types of networks including LAN, MAN, WAN and PAN. It then covers topics like network topologies, wireless networks and the OSI model. Specifically, it describes common network topologies like star, bus, ring and tree and explains the layers of the OSI model from the physical layer up to the transport layer.
Introduction to networking by vikas jagtapVikas Jagtap
Network :- “A group of computers & other devices (such as workstations, printers, or servers) that are linked together is called as Network.”
Networking :- “The concept of connected computers sharing information, resources, or both is called as Networking.”
This document discusses network topologies and local area networks (LANs). It describes physical topology as the physical placement of network components, while logical topology refers to the logical arrangement of nodes. LANs connect computers and devices within a limited area through technologies like Ethernet or wireless. Common LAN topologies include star, ring, and bus. The document also discusses how LANs work using the OSI model and provides examples of LAN applications and advantages. It defines a personal area network (PAN) as connecting devices within 10 meters of an individual.
Networking connects computing devices together to share data. It allows devices to communicate through a mix of hardware like cables and wireless equipment, and software like communication protocols. Networks can be categorized based on their geographic reach - local area networks (LANs) span a small area like a home or office, while wide area networks (WANs) connect across cities, states or globally. The largest public WAN is the Internet. Networks also use common protocols like TCP/IP to define the language devices use to communicate. While wired networks were traditionally used, wireless networking has become more popular for new installations.
1) The document outlines a course on data communication and networks across 5 units. It covers topics such as network fundamentals, data link layer, network layer, transport layer, and applications.
2) The objectives are to understand basic network concepts, components for data communication, analyze functions of various layers, and acquire knowledge of application protocols and internet technologies.
3) The outcomes are to understand how information flows through a network, identify components for different network types, understand the layered approach to data communication, and choose appropriate functionality for applications.
Academic course on Computer Network Chapter -1 for BCA, Tribhuwan University
** Applicable for other courses as well
Includes the Basic of Computer Network, Topologies, Types of Network
A network connects two or more computers. The main types are local area networks (LANs), which span a small area like a building, and wide area networks (WANs), which connect computers over a large geographical area through multiple LANs. Networks can use physical cables like twisted pair or wireless connections. They are categorized based on their topology, protocols, and architecture. Key networking hardware and software allow computers to communicate and share resources over the network.
An interconnected collection of autonomous computers is called a computer network. Networks allow computers to share resources like hardware, software, databases, and communicate with each other. The first network was ARPANET in 1969 which connected universities and defense organizations in the US. Later networks like NSFnet and the Internet improved capacity and connectivity. A network uses nodes, servers, network interface units, and types of networks can be LANs, MANs, or WANs depending on geographical reach. Networking evolved to improve sharing, reliability, and reduce costs.
In data communication,
Transmission media is a pathway that carries the information from sender to receiver.
We use different types of cables or waves to transmit data.
Data is transmitted normally through electrical or electromagnetic signals.
Synchronous optical networking (SONET) is a standardized digital communication protocol that is used to transmit a large volume of data over relatively long distances using a fiber optic medium. With SONET, multiple digital data streams are transferred at the same time over optical fiber using LEDs and laser beams.
This document provides an overview of advanced networking concepts. It begins with learning objectives around data communication, network devices, protocols, topologies and network types. It then defines key networking components like switches, routers, and firewalls. It discusses different network topologies, media like Ethernet and wireless, and various network types including LAN, WAN, SAN and more. The document is intended to help readers understand fundamental networking concepts.
A local area network (LAN) connects computers and devices within a limited geographic area like an office or building. Devices on a LAN are connected through cables, wireless links, or infrared beams and share resources like printers and files. Common types of LANs include Ethernet, Token Ring, Token Bus, and Fiber Distributed Data Interface (FDDI) networks. A LAN allows resources to be shared, communication to be convenient, data to be centralized, and internet access to be shared among connected devices. However, LANs also have costs to implement and maintain and raise security and privacy concerns.
MIS-Presentation management information systems.pptxMdSabujHossen2
The document discusses various topics related to data communication and computer networks. It provides details about the group members working on the project. It then discusses basic elements of a communication system including a sender, medium, and receiver. It explains different data transmission models such as simplex, half-duplex, and full-duplex. It also discusses data transmission speed and different categories based on bandwidth. The document covers additional topics such as data transmission media, digital and analog transmission, network topologies, types of networks, roles of communication protocols, wireless technologies and issues, elements of internet search engines, and uses of the internet.
In this slide I explain What is Data Communication and Networks and its Applications And also explain Physical Topology, Types of Physical Topologies, Categories of Networks that is LAN, WAN, MAN and coverage of Networks etc.
Program/Course : Computer System Servicing NC II
Unit of Competency : Set-up Computer Networks
Module : Install Network Cables
Learning Outcome 01: Installing Network Cables
for full compilation just visit my website.
http://computersystemsolution.com/
A computer network is a set of connected computers. Computers on a network are called nodes. The connection between computers can be done via cabling, most commonly the Ethernet cable, or wireless through radio waves. Connected computers can share resources, like access to the Internet, printers, file servers, and others. A network is a multipurpose connection, which allows a single computer to do more.
↓↓↓↓ Read More:
@ Kindly Follow my Instagram Page to discuss about your mental health problems-
-----> https://instagram.com/mentality_streak?utm_medium=copy_link
@ Appreciate my work:
-----> behance.net/burhanahmed1
Thank-you !
The document discusses computer networks and communication. It begins with an introduction to how computer networks were developed in the 1960s to enable fast and real-time data transfer for scientific research. It then defines what a network is and discusses various types of networks including LANs, WANs, MANs, peer-to-peer networks, and examples like Ethernet. It also covers network topologies, the ISO-OSI reference model, and considerations for networking like cost, training, security and more.
This document provides an introduction to computer networks. It begins with definitions of common network types including local area networks (LANs), metropolitan area networks (MANs), and wide area networks (WANs). It describes common network topologies like bus, star, ring, tree, and mesh. It also discusses network components such as physical media, interconnecting devices, computers, networking software, and applications. The document provides examples of networking applications and protocols like TCP/IP. It introduces concepts like packets, routers, and packet switching. It also discusses open systems, internet connections, network addressing, and the domain name system.
This document provides information about different types of computer networks and networking components. It defines and describes various network topologies including bus, ring, mesh, star, tree, and hybrid topologies. It also discusses different types of networks such as personal area networks, local area networks, wireless local area networks, campus area networks, metropolitan area networks, wide area networks, storage area networks, and virtual private networks. Furthermore, it covers the four main types of network cabling, common network connectors, and basic network components including end points, network interface cards, repeaters, hubs, switches, and routers.
This document provides an introduction to computer networks, including definitions of key network concepts and components. It discusses the basic applications and purposes of networks, as well as what can be found on networks including hosts, terminals, clients, and servers. It also describes common networking devices like NICs, modems, hubs, switches, and routers. Additionally, it covers network topologies, transmission modes, and the different categories of networks including LANs, MANs, and WANs.
This document discusses telecommunications and computer networks. It defines communication, telecommunications, and data communication. The objectives of communication networks are to offer timely information exchange, reduce effort and costs, and support improved management. Networks use simplex, half-duplex, and full-duplex transmission modes. Analog transmission sends continuous signals while digital transmission sends discrete values. Asynchronous transmission sends characters independently while synchronous transmission sends data in blocks. The telecommunication network model includes end user terminals, telecommunication processors, channels, computers, software, and various components that connect networks. [/SUMMARY]
This document discusses LAN and WAN network architectures. It covers key topics such as:
- LANs are privately owned networks that connect devices within a single building, while WANs provide long-distance transmission across large geographic areas.
- Common LAN technologies include Ethernet, Token Ring, and FDDI, with Ethernet being the most widely used standard.
- WANs connect multiple LANs and use transmission technologies like leased lines, circuits switching, and packet switching to transmit data over large distances.
- The document provides an overview of LAN and WAN components, protocols, topologies and transmission methods.
This document provides an introduction to computer networks presented by Ram nivas sonkar. It begins with defining what a computer network is and discusses the key components and types of networks including LAN, MAN, WAN and PAN. It then covers topics like network topologies, wireless networks and the OSI model. Specifically, it describes common network topologies like star, bus, ring and tree and explains the layers of the OSI model from the physical layer up to the transport layer.
Introduction to networking by vikas jagtapVikas Jagtap
Network :- “A group of computers & other devices (such as workstations, printers, or servers) that are linked together is called as Network.”
Networking :- “The concept of connected computers sharing information, resources, or both is called as Networking.”
This document discusses network topologies and local area networks (LANs). It describes physical topology as the physical placement of network components, while logical topology refers to the logical arrangement of nodes. LANs connect computers and devices within a limited area through technologies like Ethernet or wireless. Common LAN topologies include star, ring, and bus. The document also discusses how LANs work using the OSI model and provides examples of LAN applications and advantages. It defines a personal area network (PAN) as connecting devices within 10 meters of an individual.
Networking connects computing devices together to share data. It allows devices to communicate through a mix of hardware like cables and wireless equipment, and software like communication protocols. Networks can be categorized based on their geographic reach - local area networks (LANs) span a small area like a home or office, while wide area networks (WANs) connect across cities, states or globally. The largest public WAN is the Internet. Networks also use common protocols like TCP/IP to define the language devices use to communicate. While wired networks were traditionally used, wireless networking has become more popular for new installations.
Similar to datacommunicationnetworking-161025074805.pptx (20)
1) The document outlines a course on data communication and networks across 5 units. It covers topics such as network fundamentals, data link layer, network layer, transport layer, and applications.
2) The objectives are to understand basic network concepts, components for data communication, analyze functions of various layers, and acquire knowledge of application protocols and internet technologies.
3) The outcomes are to understand how information flows through a network, identify components for different network types, understand the layered approach to data communication, and choose appropriate functionality for applications.
This document provides an introduction to trees as a non-linear data structure. It discusses key terms like root, parent, child, leaf nodes. It also covers different types of trees like binary trees and binary search trees. Tree traversal algorithms like preorder, inorder and postorder are explained along with pseudocode. Finally, it briefly discusses applications of trees and the Huffman algorithm for data compression.
This document provides an overview of trees as data structures. It defines tree terminology like nodes, edges, leaves, subtrees, and levels. It describes binary trees and their properties like fullness and completeness. It covers traversing trees using preorder, inorder and postorder traversal orders. It explains implementing binary trees and binary search trees using linked nodes and arrays. It provides pseudocode for searching, inserting and deleting nodes from binary search trees.
This document discusses Java servlets and JavaServer Pages (JSP) technology. It provides an introduction and overview of servlets, including how they run on the server-side and support multithreading. Examples of servlet applications and usage modes are described. The document also compares JSP and servlets, explaining how JSP simplifies page development with tags while retaining Java benefits. Key components of JSP like directives, tags, expressions and scripting elements are outlined. Finally, the document discusses scalable application models using servlets and Enterprise JavaBeans.
This document is a lecture on structures in C programming. It discusses built-in and user-defined data types, with a focus on defining structures. Examples are provided for defining structures to represent complex numbers, dates, and other data. Common operations on abstract data types like addition and comparison are demonstrated. Linked lists and binary trees are also introduced as examples of user-defined data types using structures.
Heaps are a type of tree structure that can be used to implement priority queues. Heaps allow for fast insertion and deletion operations in O(log n) time. They are usually implemented as arrays, where each node satisfies the heap property of being greater than or equal to the keys of its children. This makes heaps "weakly ordered" without a strong search mechanism. Removal of the maximum element is easy by removing the root, but requires trickling down the last element to maintain the heap ordering. Insertion works by trickling new elements up until they are below a larger parent node. Heapsort uses these heap operations to sort elements in O(n log n) time by building a heap and repeatedly removing
Server-side programming with Java servlets allows dynamic web content generation. Servlets extend the capabilities of web servers by responding to incoming requests. A servlet is a Java class that implements the servlet interface. It handles HTTP requests and responses by overriding methods like doGet() and doPost(). Servlets provide better performance than CGI by using threads instead of processes to handle requests. They also offer portability, robustness, and security due to being implemented in Java. Sessions allow servlets to maintain state across multiple requests from the same user by utilizing session IDs stored in cookies.
The document discusses Document Type Definitions (DTDs) and how they are used to define the structure and legal elements of an XML document. It provides information on some key points about DTDs:
- DTDs define the valid tags and attributes that can be used in an XML document and specify the allowed sequences of elements.
- Data sent with a DTD is considered valid XML, while data sent without a DTD is well-formed XML.
- DTDs help ensure different people and programs can read each other's XML files by defining the exact elements and structure allowed in a document.
This document discusses different methods for solving recurrence relations that describe algorithms, including substitution, iteration, and the master method. It provides examples of applying these methods to solve recurrences of the form T(n) = aT(n/b) + f(n). The substitution and iteration methods are demonstrated on examples with T(n) = 2T(n/2) + n and T(n) = n + T(n-1) to show the solutions are O(n log n) and O(n), respectively.
The document discusses stacks and queues as abstract data types. It describes stacks as last-in, first-out (LIFO) data structures that can be implemented using arrays or linked lists. Elements are inserted and removed from one end, called the top. Similarly, queues are first-in, first-out (FIFO) structures where elements are inserted at the rear and removed from the front. Common operations for both include push/enqueue, pop/dequeue, isEmpty, and isFull. Example code demonstrates implementing stacks and queues in C using arrays and linked lists. Applications are given such as undo functions, method call stacks, and waiting lists.
The document describes how to empty a queue data structure in computer science. It instructs to make the front pointer point to the element before the current front element, wasting one memory location. Once this is done, the rear and front pointers will be equal, indicating an empty queue.
JavaScript is used to create interactive user interfaces on web pages by dynamically manipulating and styling web content without reloading pages. It can hide and show content, generate HTML, validate forms, and perform AJAX requests. The prompt() function displays a message and text field to accept user input, returning the input value as a string if OK is clicked or null if Cancel is clicked. JavaScript is a scripting language most commonly used for client-side web development that implements the ECMAScript standard, which defines the language syntax and basic objects while browser implementations add additional objects for windows, frames, forms, and DOM manipulation.
This document discusses string manipulation functions and regular expressions in PHP. It lists common string comparison functions like strcmp(), strstr(), and strpos() along with examples of replacing and finding substrings. Regular expressions can match patterns using character classes, quantifiers, anchors and other special characters. Examples show matching words, letters, numbers and patterns at the beginning or end of strings.
Client-side validation occurs before form submission and can improve the user experience but is not secure as validation is done in the browser. Server-side validation is needed for true security as it validates in PHP code after submission but is slower. Using both provides a good balance of convenience and security but requires the most programming effort.
Form tags allow web developers to collect user input on web pages. The <form> tag contains an "action" attribute that specifies the page where form data will be submitted and a "method" attribute that defines whether data is sent via GET or POST requests. GET passes data in the URL string while POST sends it as a separate file.
Web technology is a document about HTML and XML. It discusses that for an XML document to be valid, it must have an associated DTD declaration and comply with the constraints in the DTD. An XML document is valid if it is well-formed, refers to an accessible DTD-based schema using a Document Type Declaration, and meets the criteria expressed in the associated DTD.
The document discusses how network science has advanced understanding of complex systems. It states that understanding cellular organization and function can be improved by detecting known and predicting unknown protein complexes within a cell's protein interaction network, as these are thought to provide information on biological processes and cell metabolism. It also notes that many researchers theorize the presence of relevant functional modules in such networks, and that predictions could be an inexpensive way to guide biological experiments.
The document discusses the history and technology of the internet. It describes how ARPANET was established in 1969 as the first wide area packet switching network and how TCP/IP was developed in the 1970s as the standard communication protocol. It also summarizes key internet services like email, file transfer, and the world wide web, which allows for hyperlinked documents across a decentralized network.
This document provides an introduction to data structures and algorithms. It defines key concepts like algorithms, programs, and data structures. Algorithms are step-by-step instructions to solve a problem, while programs implement algorithms using a programming language. Data structures organize data in a way that allows programs to use it effectively. The document discusses abstract data types (ADTs), which specify operations that can be performed on data instances along with preconditions and postconditions defining what the operations do. Common ADT operations include constructors, access functions, and manipulation procedures. An example dynamic set ADT is provided to illustrate defining operations and axioms.
Hierarchical Digital Twin of a Naval Power SystemKerry Sado
A hierarchical digital twin of a Naval DC power system has been developed and experimentally verified. Similar to other state-of-the-art digital twins, this technology creates a digital replica of the physical system executed in real-time or faster, which can modify hardware controls. However, its advantage stems from distributing computational efforts by utilizing a hierarchical structure composed of lower-level digital twin blocks and a higher-level system digital twin. Each digital twin block is associated with a physical subsystem of the hardware and communicates with a singular system digital twin, which creates a system-level response. By extracting information from each level of the hierarchy, power system controls of the hardware were reconfigured autonomously. This hierarchical digital twin development offers several advantages over other digital twins, particularly in the field of naval power systems. The hierarchical structure allows for greater computational efficiency and scalability while the ability to autonomously reconfigure hardware controls offers increased flexibility and responsiveness. The hierarchical decomposition and models utilized were well aligned with the physical twin, as indicated by the maximum deviations between the developed digital twin hierarchy and the hardware.
ACEP Magazine edition 4th launched on 05.06.2024Rahul
This document provides information about the third edition of the magazine "Sthapatya" published by the Association of Civil Engineers (Practicing) Aurangabad. It includes messages from current and past presidents of ACEP, memories and photos from past ACEP events, information on life time achievement awards given by ACEP, and a technical article on concrete maintenance, repairs and strengthening. The document highlights activities of ACEP and provides a technical educational article for members.
HEAP SORT ILLUSTRATED WITH HEAPIFY, BUILD HEAP FOR DYNAMIC ARRAYS.
Heap sort is a comparison-based sorting technique based on Binary Heap data structure. It is similar to the selection sort where we first find the minimum element and place the minimum element at the beginning. Repeat the same process for the remaining elements.
Low power architecture of logic gates using adiabatic techniquesnooriasukmaningtyas
The growing significance of portable systems to limit power consumption in ultra-large-scale-integration chips of very high density, has recently led to rapid and inventive progresses in low-power design. The most effective technique is adiabatic logic circuit design in energy-efficient hardware. This paper presents two adiabatic approaches for the design of low power circuits, modified positive feedback adiabatic logic (modified PFAL) and the other is direct current diode based positive feedback adiabatic logic (DC-DB PFAL). Logic gates are the preliminary components in any digital circuit design. By improving the performance of basic gates, one can improvise the whole system performance. In this paper proposed circuit design of the low power architecture of OR/NOR, AND/NAND, and XOR/XNOR gates are presented using the said approaches and their results are analyzed for powerdissipation, delay, power-delay-product and rise time and compared with the other adiabatic techniques along with the conventional complementary metal oxide semiconductor (CMOS) designs reported in the literature. It has been found that the designs with DC-DB PFAL technique outperform with the percentage improvement of 65% for NOR gate and 7% for NAND gate and 34% for XNOR gate over the modified PFAL techniques at 10 MHz respectively.
Advanced control scheme of doubly fed induction generator for wind turbine us...IJECEIAES
This paper describes a speed control device for generating electrical energy on an electricity network based on the doubly fed induction generator (DFIG) used for wind power conversion systems. At first, a double-fed induction generator model was constructed. A control law is formulated to govern the flow of energy between the stator of a DFIG and the energy network using three types of controllers: proportional integral (PI), sliding mode controller (SMC) and second order sliding mode controller (SOSMC). Their different results in terms of power reference tracking, reaction to unexpected speed fluctuations, sensitivity to perturbations, and resilience against machine parameter alterations are compared. MATLAB/Simulink was used to conduct the simulations for the preceding study. Multiple simulations have shown very satisfying results, and the investigations demonstrate the efficacy and power-enhancing capabilities of the suggested control system.
Using recycled concrete aggregates (RCA) for pavements is crucial to achieving sustainability. Implementing RCA for new pavement can minimize carbon footprint, conserve natural resources, reduce harmful emissions, and lower life cycle costs. Compared to natural aggregate (NA), RCA pavement has fewer comprehensive studies and sustainability assessments.
Adaptive synchronous sliding control for a robot manipulator based on neural ...IJECEIAES
Robot manipulators have become important equipment in production lines, medical fields, and transportation. Improving the quality of trajectory tracking for
robot hands is always an attractive topic in the research community. This is a
challenging problem because robot manipulators are complex nonlinear systems
and are often subject to fluctuations in loads and external disturbances. This
article proposes an adaptive synchronous sliding control scheme to improve trajectory tracking performance for a robot manipulator. The proposed controller
ensures that the positions of the joints track the desired trajectory, synchronize
the errors, and significantly reduces chattering. First, the synchronous tracking
errors and synchronous sliding surfaces are presented. Second, the synchronous
tracking error dynamics are determined. Third, a robust adaptive control law is
designed,the unknown components of the model are estimated online by the neural network, and the parameters of the switching elements are selected by fuzzy
logic. The built algorithm ensures that the tracking and approximation errors
are ultimately uniformly bounded (UUB). Finally, the effectiveness of the constructed algorithm is demonstrated through simulation and experimental results.
Simulation and experimental results show that the proposed controller is effective with small synchronous tracking errors, and the chattering phenomenon is
significantly reduced.
2. Data & Signals
Data can be analog or digital
Analog data refers to information that is continuous
Analog data take on continuous values
Digital data refers to information that has discrete states
2
3. Data Communication
3
Data Communications is the transfer of data or
information between a source and a receiver.
The source transmits the data and the receiver
receives it.
The purpose of data communications is to
provide the rules and regulations that allow
computers with different disk operating systems,
languages, cabling and locations to share
resources.
The rules and regulations are called protocols
and standards in data communications.
5. Data Flow
Data flow is the flow of data between two
points.
The direction of the data flow can be described
as:
1. Simplex:
data flows in only one direction on the
data communication line (medium). Examples
are radio and television broadcasts.
5
6. 2. Half-Duplex
data flows in both directions but only one
direction at a time on the data communication
line.
For example, a conversation on walkie-talkies
is a half-duplex data flow.
Each person takes turns talking. If both talk at
once - nothing occurs!
6
7. 3. Full Duplex
Data flows in both directions simultaneously.
Modems are configured to flow data in both
directions.
Bi-directional both directions simultaneously!
7
8. Modems
A modem (MOdulator/DEModulator) is a
device that enables a computer to transmit
data over, for example, telephone or cable
lines. Computer information is stored
digitally, whereas information transmitted
over telephone lines is transmitted in the form
of analog waves.
8
9. 9
How fast the modem can
transmit and receive data?
At slow rates, modems are measured in terms
of baud rates
The slowest rate is 300 baud
At higher speeds, modems are measured in
terms of bits per second (bps)
The fastest modems run at 57,600 bps
The faster the transmission rate, the faster
you can send and receive data
For example, if the device sending data to
your computer is sending it at 2,400 bps, you
must receive it at 2,400 bps
10. About Voice/Data
10
Many modems support a switch to change
between voice and data modes
In data mode, the modem acts like a regular
modem
In voice mode, the modem acts like a regular
telephone
Modems that support a voice/data switch have
a built-in loudspeaker and microphone for
voice communication
12. Data Compression modem
12
Some modems perform data compression,
which enables them to send data at faster
rates
However, the modem at the receiving end
must be able to decompress the data using
the same compression technique.
13. Fax Capability modem
13
Most modern modems are fax modems, which
means that they can send and receive faxes.
14. Digital Connection
The connection between the modem and
terminal/computer is a digital connection.
A basic connection consists of a Transmit Data
(TXD) line, a Receive Data (RXD) line and
many hardware handshaking control lines.
The control lines determine whose turn it is to
talk (modem or terminal), if the
terminal/computer is turned on, if the modem
is turned on, if there is a connection to
another modem, etc.
14
15. Analog Connection
The connection between the modem and the
outside world (the phone line) is an analog
connection.
The voice channel has a bandwidth of 0-4 kHz
but only 300 - 3400 Hz is usable for data
communications.
The modem converts digital information into
tones (frequencies) for transmitting through
the phone lines. The tones are in the 300-3400
Hz Voice Band.
15
16. Types of Modems
16
External Modem
– External modems sit next to the computer
and connect to the serial port using a
straight-through serial cable.
Internal Modem
– An internal modems is a plug-in circuit
board that sits inside the computer. It
incorporates the serial port on-board.
– They are less expensive than external
modems because they do not require a
case, power supply and serial cable.
17. Telecommunications
17
Telephones and networking work hand in hand.
The common goal is to join distantly located
Local Area Networks into Metropolitan and Wide
Area Networks (MANs and WANs).
Talking to someone on the phone uses voice
channels.
We use voice channels for modem
communications to connect to the Internet.
Due to the bandwidth limits on voice channels,
the data transfer rate is relatively slow.
18. Voice Channels
18
Voice Channel: Dial-up connection through a
modem using standard telephone lines.
Typical voice channel communication rates
are: 300, 1200, 2400, 9600, 14.4k, 19.2k, 28.8k,
33.6k and 56 kbps (bits per second).
19. Data Channels
19
Data channels are dedicated lines for
communicating digitized voice and data.
At the end of 1996, there was a major milestone
when more data was communicated in North
America's telecommunications system than
voice.
Data Channels are special communications
channels provided by "common carriers" such as
Telus, Sprint, Bell Canada, AT&T, etc. for
transferring digital data.
Data Channels are also called "Leased Lines".
20. Data Channels(Contd.)
20
They are "directly" connected: you don't have
to dial a connection number.
The connections are up and running 24 hours
per day.
They appear to work as if there were a wire
running directly between the source and the
destination.
Typical transfer rates for data channels are: 56
k, 128k, 1.544 M, 2.08 M, 45M and 155 Mbps.
21. Data Channels(Contd.)
21
Common carriers charge for data
connections by:
–The amount of data transferred
(megabytes per month)
–The transfer rate (bits per second)
–The amount of use (time per month)
22. What is a network?
22
A network can consist of two computers
connected together on a desk or it can consist
of many Local Area Networks (LANs)
connected together to form a Wide Area
Network (WAN) across a continent.
The key is that two or more computers are
connected together by a medium and are
sharing resource.
These resources can be files, printers,
hard•drives, or CPU number-crunching power.
25. Local loops
The Local Loop is often called "the last mile"
It refers to the last mile of analog phone line
that goes from the telephone company's
central office (CO) to your house.
25
26. Local Area Networks (LANs)
LANs (local area networks) are networks that
connect computers and resources together in
a building or buildings that are close together.
The components used by LANs can be divided
into cabling standards, hardware, and
protocols.
26
27. Metropolitan Area Networks(MANs)
Metropolitan Area Networks (MANs) are
networks that connect LANs together within a
city.
The main criterion for a MAN is that the
connection between LANs is through a local
exchange carrier (the local phone company).
27
28. Wide Area Networks(WANs)
Wide Area Networks (WANs) connect LANs
together between cities.
The main difference between a MAN and a
WAN is that the WAN uses Long Distance
Carriers. Otherwise the same protocols and
equipment are used as a MAN.
28
29. 29
Network Topology
What is a Topology?
The physical topology of a network
refers to the configuration of
cables, computers, and other
peripherals.
Main types of physical topologies
1. Linear Bus
2. Star
3. Star-wired ring
4. Tree
30. 30
Linear Bus
A linear bus topology consists of a main
run of cable with a terminator at each
end (See figure). All nodes (file server,
workstations, and peripherals) are
connected to the linear cable. Ethernet
and local talk networks use a linear bus
topology.
31. Advantages of linear bus
Easy to connect a computer or peripheral to a
linear bus.
Requires less cable length than a star
topology.
Disadvantages of linear bus
Entire network shuts down if there is a break
in the main cable.
Terminators are required at both ends of the
backbone cable.
Difficult to identify the problem if the entire
network shuts down.
Not meant to be used as a stand-alone
solution in a Largebuilding
31
Linear Bus
32. 32
Star
A star topology is designed with each node
(file server, workstations, and peripherals)
connected directly to a central network hub or
concentrator (See figure).
Data on a star network passes through the
hub or concentrator before continuing to its
destination.
33. 33
Star
Advantages of star
Easy to install and wire.
No disruptions to the network then connecting
or removing devices.
Easy to detect faults and to remove parts.
Disadvantages of star
Requires more cable length than a linear
topology.
If the hub or concentrator fails, nodes
attached are disabled.
More expensive than linear bus topologies
because of the cost of the concentrators.
34. Star-Wired Ring
34
A star-wired ring topology may appear
(externally) to be the same as a star topology.
Internally, the MAU (multistation access unit)
of a star-wired ring contains wiring that allows
information to pass from one device to
another in a circle or ring
35. Tree
A tree topology combines characteristics of linear bus
and star topologies.
It consists of groups of star-configured workstations
connected to a linear bus backbone cable
Tree topologies allow for the expansion of an existing
network, and enable schools to configure a network to
meet their needs.
35
36. Tree
36
Advantages
– Point-to-point wiring for individual segments.
– Supported by several hardware and software
vendors.
Disadvantages
– Overall length of each segment is limited by the type
of cabling used.
– If the backbone line breaks, the entire segment goes
down.
– More difficult to configure and wire than other
topologies.
37. Considerations When Choosing a Topology:
37
Money. A linear bus network may be the least
expensive way to install a network; you do not
have to purchase concentrators.
Length of cable needed. The linear bus
network uses shorter lengths of cable.
Future growth. With a star topology,
expanding a network is easily done by adding
another concentrator.
Cable type. The most common cable in
schools is unshielded twisted pair, which is
most often used with star topologies.
38. SummaryChart
38
Physical Topology Common Cable Common Protocol
Linear Bus Twisted Pair
coaxial Fiber
Ethernet
LocalTalk
Star Twisted Pair
Fiber
Ethernet
LocalTalk
Star-Wired Ring Twisted Pair Token Ring
Tree Twisted Pair
Coaxial
Fiber
Ethernet
39. Introduction to the ISO - OSI Model
39
The ISO (International Standards
Organization) has created a layered model,
called the OSI (Open Systems Interconnect)
model.
The purpose of the layers is to provide clearly
defined functions that can improve
Internetwork connectivity between
"computer" manufacturing companies.
Each layer has a standard defined input and a
standard defined output.
40. 7 layers of the OSI Model
40
7. Application Layer (Top Layer)
6. Presentation Layer
5. Session Layer
4. Transport Layer
3. Network Layer
2. Data Link Layer
1. Physical Layer (Bottom Layer)
44. Data Communication Network
44
The major criteria that a data communication
network must meet are:
–Performance
–Consistency
–Reliability
–Recovery
–Security
45. Performance
45
– Software program
Performance is the defined as the rate of
transference of error-free data.
It is measured by the response time.
Response time is the elapsed time between
the end of an inquiry and the beginning of a
response
– Example requesting a file transfer and starting the
file transfer.
Factors that affect response time are:
– Number of Users:
– Transmission Speed:
– Hardware Type:
46. Consistency
46
Consistency is the predictability of response
time and accuracy of data.
– For example, if the "normal" response time is 3
seconds for printing to a network printer but a
response time of over 30 seconds occurs, we know
that there is a problem in the system!
47. Reliability
47
Reliability is the measure of how often a
network is usable.
MTBF (Mean Time Between Failures) is a
measure of the average time a component is
expected to operate between failures, and is
normally provided by the manufacturer.
A network failure can be caused by a problem
with the hardware, the data carrying medium,
or the Network Operating System.
48. Recovery
48
Recovery is the network's ability to return to a
prescribed level of operation after a network
failure.
This level is where the amount of lost data is
nonexistent or at a minimum. Recovery is
based on having back-up files.
49. Security
49
Security is the protection of hardware,
software and data from unauthorized access.
Restricted physical access to computers,
password protection, limiting user privileges
and data encryption are common security
methods.
Anti-virus monitoring programs to defend
against computer viruses are also a security
measure.
50. Application
50
Electronic Mail (e-mail or Email)
Teleconferencing allows people in different
regions to "attend" meetings using telephone
lines.
Automated Banking Machines allow banking
transactions to be performed everywhere
Groupware is the latest network application. It
allows user groups to share documents,
schedules databases, etc. (ex. Lotus Notes)
51. Physical Connection
51
The physical connection determines how many
bits (1's or 0's) can be transmitted in a single
instance of time.
If only 1 bit of information can be transmitted
over the data transmission medium at a time
then it is considered a serial communication.
If more than 1 bit of information is transmitted
over the data transmission medium at a time
then it is considered a parallel communication.
53. Communications
53
Advantages
Parallel : faster
transfer rates
Serial : long
distances
Disadvantages
Parallel: short
distance only
Serial : slow transfer
rates
54. Transmission Media- Guided
54
There are 2 basic categories of transmission
media: guided and unguided.
Guided transmission media uses a cabling
system that guides the data signals along a
specific path.
Unguided transmission media consists of a
means for the data signals to travel but
nothing to guide them along a specific path.
56. Open wire
Open wire is traditionally used to describe the
electrical wire strung along power poles.
There is a single wire strung between poles.
No shielding or protection from noise
interference is used.
56
57. Twisted Pair
The wires in twisted pair cabling are twisted
together in pairs.
Each pair consists of a wire used for the +ve
data signal and a wire used for the -ve data
signal.
Any noise that appears on 1 wire of the pair
will also occur on the other wire.
When the noise appears on both wires, it
cancels or nulls itself out at the receiving end.
57
58. Unshielded Twisted Pair
The degree of reduction in noise interference is
determined specifically by the number of turns per foot.
Increasing the number of turns per foot reduces the
noise interference.
To further improve noise rejection, a foil or wire braid
"shield" is woven around the twisted pairs.
Cables with a shield are called shielded twisted pair and
are commonly abbreviated STP.
Cables without a shield are called unshielded twisted
pair or UTP.
58
59. Coaxial cable
Coaxial cable consists of two conductors.
The inner conductor is held inside an insulator
with the other conductor woven around it
providing a shield.
An insulating protective coating called a jacket
covers the outer conductor.
59
60. Coaxial cable
60
The outer shield protects the inner conductor
from outside electrical signals.
The distance between the outer conductor
(shield) and inner conductor plus the type of
material used for insulating the inner
conductor determine the cable properties or
impedance.
Typical impedances for coaxial cables are 75
ohms for Cable TV, 50 ohms for Ethernet
Thinnet and Thicknet.
61. Optical fiber
Optical fiber consists of thin glass fibers that can carry
information at frequencies in the visible light spectrum
and beyond.
The typical optical fiber consists of a very narrow strand
of glass called the core.
Around the core is a concentric layer of glass called the
cladding.
Coating the cladding is a protective coating consisting of
plastic, it is called the Jacket.
61
62. Optical fiber
An important characteristic of fiber optics is refraction.
Refraction is the characteristic of a material to either
pass or reflect light.
When light passes through a medium, it "bends" as it
passes from one medium to the other.
An example of this is when we look into a pond of
water.
62
63. Optical fiber
If the angle of incidence is small, the light rays
are reflected and do not pass into the water.
If the angle of incident is great, light passes
through the media but is bent or refracted.
63
64. Advantages of Optical fiber
64
Noise immunity: RFI and EMI immune
(RFI - Radio Frequency Interference,
EMI -Electromagnetic Interference)
Security: cannot tap into cable.
Large Capacity due to BW (bandwidth)
No corrosion (destroy metal)
Longer distances than copper wire
Smaller and lighter than copper wire
Faster transmission rate
65. Disadvantages of Optical fiber
65
Physical vibration will show up as signal
noise!
Limited physical arc of cable. Bend it
too much and it will break!
Difficult to splice (to join)
66. Comparison
66
The following compares the usable bandwidth
of the different guided transmission media.
Cable Type
Open Cable
Twisted Pair
Coaxial Cable
Optical Fiber
Bandwidth
0 - 5 MHz
0 - 100 MHz
0 - 600 MHz
0 - 1 GHz
67. Transmission Media - Unguided
67
Unguided transmission media is data signals
that flow through the air.
They are not guided or bound to a channel to
follow.
They are classified by the type of wave
propagation.
– RF (Radio Frequency) Propagation
– Microwave Propagation
– Satellite Propagation
68. RF Propagation
68
There are three types of RF (radio frequency)
propagation:
1.Ground Wave
2.Ionospheric
3.Line of Sight (LOS)
69. Groundwave propagation
Ground wave propagation follows the
curvature of the Earth.
Ground waves have carrier frequencies up to 2
MHz. AM Radio is an example of ground wave
propagation.
69
CopyrightMr.AnjanMahanta LCCTInternational Studies Program
70. Ionospheric propagation
Ionospheric propagation bounces off of the
Earth's ionospheric layer in the upper
atmosphere.
It operates in the frequency range of 30 - 85
MHz.
Because it depends on the Earth's ionosphere,
it changes with the weather and time of day.
Ham radios operate in this range.
70
71. Line of sight propagation
Line of sight propagation transmits exactly in
the line of sight.
The receive station must be in the view of the
transmit station.
It is limited by the curvature of the Earth for
ground-based stations (100 km, from horizon
to horizon).
Examples of line of sight propagation are: FM
radio, microwave and satellite.
71
72. Microwave
Microwave transmission is line of sight
transmission.
The transmit station must be in visible contact
with the receive station.
Typically the line of sight due to the Earth's
curvature is only 50 km to the horizon!
Repeater stations must be placed so the data
signal can hop, skip and jump across the
country.
72
73. Microwave
73
Microwaves operate at high operating
frequencies of 3 to 10 GHz.
This allows them to carry large quantities of
data due to their large bandwidth.
Advantages:
– They can carry high quantities of information due to
their high operating frequencies.
– Low cost land purchase: each tower occupies only a
small area.
– High frequency/short wavelength signals require
small antennae.
74. Microwave
74
Disadvantages
– Attenuation by solid objects: birds, rain, snow and
fog.
– Reflected from flat surfaces like water and metal.
– Diffracted (split) around solid objects.
– Refracted by atmosphere, thus causing beam to be
projected away from receiver.
75. Satellite
Satellites are transponders (units that receive
on one frequency and retransmit on another)
that are set in geostationary orbits directly
over the equator.
75
76. Satellite
These geostationary orbits are 36,000 km from
the Earth's surface.
At this point, the gravitational pull of the Earth
and the centrifugal force of Earth's rotation
are balanced and cancel each other out.
76
77. Satellite
77
The uplink is the transmitter of data to the
satellite.
The downlink is the receiver of data.
Uplinks and downlinks are also called Earth
stations because they are located on the
Earth.
The footprint is the "shadow" that the satellite
can transmit to, the shadow being the area
that can receive the satellite's transmitted
signal.
78. Networking Devices
78
Repeaters:Repeaters are physical hardware devices:
they have a primary function to regenerate the
electrical signal
The purpose of a repeater is to extend the LAN Segment
beyond its physical limits
Typically, repeaters are used to connect two physically
close buildings together (when they are too far apart to
just extend the segment).
They can be used to connect floors of a building that
would normally surpass the maximum allowable
segment length.
For large extensions two Repeaters are required but for
shorter extensions, only one Repeater may be required.
82. Networking Devices
Hubs:Hubs are used to provide a Physical Star
Topology.
At the center of the star is the Hub, with the
network nodes located on the tips of the star.
The Hub is installed in a central wiring closet,
with all the cables extending out to the
network nodes.
82
85. Networking Devices
85
Purpose of a Bridge
The purposes of a Bridge are the
following:
– Isolates networks by MAC addresses
– Manages network traffic by filtering
packets
– Translates from one protocol to
another
87. Networking Devices
87
Manages network traffic by filtering packets
Bridges listen to the network traffic, and build
an image of the network on each side of the
bridge.
This image of the network indicates the
location of each node
With this information, a bridge can make a
decision whether to forward the packet across
the bridge
This process of deciding whether or not to
forward a packet is termed "filtering packets."
88. Networking Devices
88
Translates from one protocol to another
Bridges are store and forward devices.
They receive a packet on the local segment,
store it, and wait for the remote segments to
be clear before forwarding the packet.
89. Networking Devices
Reasons to use a Bridge
Bandwidth: Reduce traffic by segmentation
Reliability: If 1 segment goes down, it does
not take down the complete LAN
Translation: Translate different Data Link
protocols
89
90. Networking Devices
90
Gateways
A Gateway is the Hardware/Software device
that is used to interconnect LANs & WANs
using mainframe computers
Example: DECnet and IBM's SNA
Often, the router that is used to connect a LAN
to the Internet will be called a gateway.
It will have added capability to direct and filter
higher layer protocols (layer 4 and up) to
specific devices (such as web servers, ftp
servers and e-mail servers).
91. Protocol IEEE-802.3
91
The IEEE-802.3 Protocol is based on the Xerox
Network Standard (XNS) called Ethernet
These are the four versions of the Ethernet
frame
– Ethernet_802.2
– Ethernet_802.3
– Ethernet_II
– Ethernet_SNAP
NOTE: The Source and Destination must have
the same Ethernet Frame type in order to
communicate.
92. Protocol IEEE-802.3
92
IEEE 802.3 defines five media types of
IEEE 802.3 Ethernet Types shown
below:
1. IEEE 802.3 - 10Base5 (Thick Coax) is used
only as backbones to networks. Backbones are
lines that connect buildings & network
equipment together (such as Bridges, Routers,
Hubs, Concentrators, Gateways, etc.).
10Base5 is now being replaced by either Thin
Coax or fiber optics.
93. Protocol IEEE-802.3
93
2.IEEE 802.3a - 10Base2 is commonly used
in new installations as a backbone to
connect buildings and network equipment
together.
10Base2 (Thin Coax) is also used to connect
work stations together, but the preferred
choice is to use 10BaseT.
3.IEEE 802.3b - 10Broad36 is rarely used; it
combines analog and digital signals together.
Broadband means that a mixture of signals
can be sent on the same medium.
94. Protocol IEEE-802.3
94
4.IEEE 802.3e - 1 Base 5 StarLAN is a slow 1
Mbps standard that has been replaced by Thin
Coax or Twisted Pair.
5.IEEE 802.3i - 10BaseT is commonly used to
connect workstations to network hubs.
The network hubs can use 10BaseT (Twisted
Pair) to connect to other Hubs.
95. 10 Base T (Twisted Pair Cable)
95
10BaseT uses unshielded twisted pair (UTP)
cable.
The cable is flexible and easy to work with.
The cable has a characteristic impedance of
100 ohms.
There are 2 pairs of twisted wires used with
10BaseT: separate Rx (receive) and Tx
(transmit) pairs.
The lines are balanced lines to minimize noise
and there are a Rx+ & Rx- pair and a Tx+ &
Tx- pair.
96. 10 Base T (Twisted Pair Cable)
96
The nodes are connected to a MPR (multi port
repeater), also called a Concentrator, or Hub.
Maximum Nodes
For 10BaseT, the maximum allowed number of
nodes is 128 (on one segment).
Maximum Distance between Nodes & Hub
The maximum distance between nodes & Hub
is 100 m.
97. Cable Termination and Connector
The standard termination is 100 ohms.
The end connector is an "RJ45" quick
disconnect connector.
The cable is internally terminated at the NIC
(Network Interface Card) and Hub.
97
99. TCP/IP Protocols
99
Network Devices are network interface
cards (NIC) and their software drivers.
Typically, they are Ethernet cards,
Token Ring cards, and WAN links (such
as ISDN or Frame Relay), and they can
also be modems and serial ports.
IP stands for Internet Protocol. Its main
job is to find the best route--through
the Internet--to the destination.
IP uses IP addresses to identify the host
machine and the network.
100. TCP/IP Protocols
100
A typical IP address is a 32 bit number, and
looks like 142.110.237.1.
In this case, 142.110.237.0 identifies the
network address, and 0.0.0.1 identifies the host
machine.
ARP stands for Address Resolution Protocol
and it is used to map IP addresses to MAC
addresses.
ICMP stands for Internet Control Message
Protocol, and is used mainly for
troubleshooting TCP/IP network connections.
101. TCP/IP Protocols
101
TCP stands for Transmission Control Protocol,
and is used to guarantee end to end delivery
of segments of data.
TCP is used to put out of order segments in
order, and to check for transmission errors.
UDP stands for User Datagram Protocol, and is
a connectionless service.
This results in a low overhead and fast transfer
service (relies on the upper layer protocols to
provide error checking and delivery of data).
102. In the Application layer lies many hundreds of network-
aware programs and services such as the following:
HTTP (80) - Hyper Text Transport Protocol, which is used
for transferring web pages.
SNMP (161/162)- Simple Network Management Protocol,
which is used for managing network devices.
FTP (20/21)- File Transfer Protocol, which is used for
transferring files across the network.
TFTP (69)- Trivial File Transfer Protocol, which is a low
overhead fast transfer FTP protocol.
SMTP (25)- Simple Mail Tranfer Protocol, which is used
for transferring email across the Internet.
Telnet (23)- An application for remotely logging into a
server across the network.
NNTP (119)- Network News Transfer Protocol, which is
used for transferring news.
* The numbers, shown in brackets next to the protocols, are called the
102
103. Wireless Network
103
CopyrightMr.AnjanMahanta LCCTInternational Studies Program
What is wireless networking?
A wireless network is simply two or
more computers (and maybe printers)
linked by radio waves.
There are various other devices that
can connect to this wireless network.
This arrangement uses a protocol
(method of communication) called, IEEE
802.11b, or Wi-Fi
104. Range & Performance
104
Wi-Fi is currently the fastest wireless
technology.
It can transmit through walls and floors at
speeds of up to 11 Mbps.
Bandwidths available:-
11Mbps
22Mbps
54Mbps
Super G 108Mbps
105. Wireless adapters
Wireless network adapters can be internal (inserted in a
computer) or external (housed in a separate case).
The two general types of wireless adapters are:
USB adapter: Connects through a USB cable to a USB
port on your desktop computer. USB adapters are
popular because they are easy to install and to swap
between desktop computers as necessary.
Notebook adapter: Fits into the PCMCIA slot on your
laptop or other portable computer. Notebook adapters
eliminate the need for cable connections to the
computer and are popular among users who value
mobility.
105
106. Benefits of wireless network
106
Convenience: You can set up wireless
connections without having to run cables or
open computer cases.
Mobility: Mobility might be relatively
unimportant for a desktop computer but can
be an important benefit if you have a laptop or
notebook computer.