This document discusses concepts in data communication including components, measurement, transmission modes, transmission media, and transmission methods. It covers the five basic components of a data communication system: message, sender, receiver, medium, and protocol. It describes different types of transmission media including guided (wired) media like twisted pair, coaxial, and optical fiber cables and unguided (wireless) media like radio frequency propagation. It also discusses analog and digital transmission methods.
Transmission media can be either wired (guided) or wireless (unguided) and are used to transmit signals from one device to another. Wired media include twisted pair, coaxial cable, and fiber optic cable. Wireless media transmit electromagnetic waves without a physical conductor and include radio waves, microwaves, and infrared. The type of media used depends on factors like bandwidth, distance, data rate, susceptibility to interference, and cost. Each media has its own advantages and limitations for different communication applications.
1) There are two main categories of transmission media - guided and unguided. Guided media uses cabling to guide signals along a path, while unguided media transmits electromagnetic waves without a physical conductor.
2) Common guided media include twisted pair, coaxial cable, and optical fiber. Twisted pair has low bandwidth and is susceptible to interference, while coaxial cable and optical fiber can transmit signals over longer distances and have greater bandwidth.
3) Unguided or wireless transmission uses radio waves, microwaves, and infrared to transmit signals through the air without a physical path. It is available to anyone who can receive the signals.
Transmission media is the physical medium used to transmit data between a sender and receiver. The two main types are guided and unguided media. Guided media uses physical pathways like cables to direct signals over shorter distances at high speeds securely. Common examples are twisted pair, coaxial, and fiber optic cables. Unguided media transmits electromagnetic waves without physical pathways, broadcasting signals through the air over longer distances less securely. Common examples are radio waves, microwaves, and infrared waves used in wireless technologies.
This document provides an overview of different transmission media used for data communication, including both guided and unguided media. It discusses various types of guided media such as twisted pair cables, coaxial cables, and fiber optic cables. It describes their characteristics, applications, advantages and disadvantages. The document also covers unguided or wireless transmission media such as radio waves, microwaves, and infrared. It explains propagation methods for unguided signals and the role of antennas. Finally, it discusses some issues with signal transmission such as attenuation, distortion and noise.
This document discusses various types of transmission media and modes. It describes guided media like twisted pair cable, coaxial cable and fiber optic cable. It also describes unguided or wireless transmission media like radio waves, microwaves and infrared. For transmission modes, it explains serial vs parallel transmission and synchronous vs asynchronous transmission. Isochronous transmission with fixed bit transmission and equal gaps is also discussed.
The document discusses key aspects of wireless communication reference models including:
1. It describes the layers of the reference model from the physical layer up to the application layer and their main functions.
2. It covers topics like frequency ranges used for wireless transmission, common modulation techniques, and effects of signal propagation like multipath propagation.
3. It discusses technologies and standards used for wireless networks and regulations set by organizations like ITU.
The document discusses various types of transmission media used in computer networks. It describes guided media such as twisted pair cable, coaxial cable, and optical fiber. Twisted pair cable comes in categories based on bandwidth and can be unshielded or shielded. Coaxial cable uses a central conductor surrounded by insulation and shielding. Optical fiber transmits signals in the form of light pulses through glass or plastic strands. Unguided media like radio waves, microwaves, and infrared waves transmit electromagnetic signals through the air without physical conductors. Each type of transmission media has characteristics like bandwidth, noise immunity, and cost that make some more suitable than others for different network applications.
Transmission media are located below the physical layer and are used to transmit signals representing data. There are two main types of transmission media: guided media (wired), which provide a conduit for transmission, and unguided media (wireless), which transmit via electromagnetic waves without a physical pathway. Common guided media include twisted-pair cable, coaxial cable, and fiber-optic cable. Unguided media include radio waves, microwaves, and infrared. Each type of transmission media has different characteristics that determine its suitable uses.
Transmission media can be either wired (guided) or wireless (unguided) and are used to transmit signals from one device to another. Wired media include twisted pair, coaxial cable, and fiber optic cable. Wireless media transmit electromagnetic waves without a physical conductor and include radio waves, microwaves, and infrared. The type of media used depends on factors like bandwidth, distance, data rate, susceptibility to interference, and cost. Each media has its own advantages and limitations for different communication applications.
1) There are two main categories of transmission media - guided and unguided. Guided media uses cabling to guide signals along a path, while unguided media transmits electromagnetic waves without a physical conductor.
2) Common guided media include twisted pair, coaxial cable, and optical fiber. Twisted pair has low bandwidth and is susceptible to interference, while coaxial cable and optical fiber can transmit signals over longer distances and have greater bandwidth.
3) Unguided or wireless transmission uses radio waves, microwaves, and infrared to transmit signals through the air without a physical path. It is available to anyone who can receive the signals.
Transmission media is the physical medium used to transmit data between a sender and receiver. The two main types are guided and unguided media. Guided media uses physical pathways like cables to direct signals over shorter distances at high speeds securely. Common examples are twisted pair, coaxial, and fiber optic cables. Unguided media transmits electromagnetic waves without physical pathways, broadcasting signals through the air over longer distances less securely. Common examples are radio waves, microwaves, and infrared waves used in wireless technologies.
This document provides an overview of different transmission media used for data communication, including both guided and unguided media. It discusses various types of guided media such as twisted pair cables, coaxial cables, and fiber optic cables. It describes their characteristics, applications, advantages and disadvantages. The document also covers unguided or wireless transmission media such as radio waves, microwaves, and infrared. It explains propagation methods for unguided signals and the role of antennas. Finally, it discusses some issues with signal transmission such as attenuation, distortion and noise.
This document discusses various types of transmission media and modes. It describes guided media like twisted pair cable, coaxial cable and fiber optic cable. It also describes unguided or wireless transmission media like radio waves, microwaves and infrared. For transmission modes, it explains serial vs parallel transmission and synchronous vs asynchronous transmission. Isochronous transmission with fixed bit transmission and equal gaps is also discussed.
The document discusses key aspects of wireless communication reference models including:
1. It describes the layers of the reference model from the physical layer up to the application layer and their main functions.
2. It covers topics like frequency ranges used for wireless transmission, common modulation techniques, and effects of signal propagation like multipath propagation.
3. It discusses technologies and standards used for wireless networks and regulations set by organizations like ITU.
The document discusses various types of transmission media used in computer networks. It describes guided media such as twisted pair cable, coaxial cable, and optical fiber. Twisted pair cable comes in categories based on bandwidth and can be unshielded or shielded. Coaxial cable uses a central conductor surrounded by insulation and shielding. Optical fiber transmits signals in the form of light pulses through glass or plastic strands. Unguided media like radio waves, microwaves, and infrared waves transmit electromagnetic signals through the air without physical conductors. Each type of transmission media has characteristics like bandwidth, noise immunity, and cost that make some more suitable than others for different network applications.
Transmission media are located below the physical layer and are used to transmit signals representing data. There are two main types of transmission media: guided media (wired), which provide a conduit for transmission, and unguided media (wireless), which transmit via electromagnetic waves without a physical pathway. Common guided media include twisted-pair cable, coaxial cable, and fiber-optic cable. Unguided media include radio waves, microwaves, and infrared. Each type of transmission media has different characteristics that determine its suitable uses.
Transmission media are the means by which data is transmitted over long distances. Common transmission media include guided media like coaxial cable, twisted pair cable, and fiber optic cable as well as unguided or wireless media that transmit signals through air like radio waves, microwaves, and infrared. Each type of transmission medium has its own characteristics and applications. For example, coaxial cable provides good bandwidth and noise immunity but is more expensive than twisted pair cable. Fiber optic cable has the highest bandwidth but requires specialized equipment. Wireless transmission uses electromagnetic signals of varying frequencies that propagate through the air. [/SUMMARY]
This document discusses different types of transmission media used for data communication. It describes guided media like twisted pair wires, coaxial cables, and optical fibers. It also covers wireless or unguided media such as terrestrial microwave, satellite microwave, broadcast radio, and infrared. For each medium, it provides details on characteristics, advantages, disadvantages, and applications. The key factors that affect the quality of a transmission medium are its bandwidth, interference levels, and transmission impairments. Optical fiber has the highest bandwidth capacity but was initially more expensive over short distances.
1. The document discusses various wireless transmission methods including radio transmission, microwave transmission using terrestrial or satellite systems, and infrared transmission.
2. It provides details on how wireless communication systems work by modulating, amplifying and radiating a carrier signal using an antenna, which can then be received by another antenna tuned to the same frequency.
3. The key types of wireless transmissions are described as direct line-of-sight waves, ground-based surface waves that follow the earth's curvature, and skywaves that are reflected by the ionosphere for long distance propagation.
There are two main types of transmission media: guided and unguided. Guided media like twisted pair cable and coaxial cable have a physical path that signals travel along, while unguided media like wireless transmission propagate through free space. Key factors that determine the performance of a transmission medium include its bandwidth, data rate, distance capabilities, and susceptibility to interference. Common guided media include twisted pair, coaxial cable, and optical fiber, each with their own characteristics and applications for voice, data, and video transmission. Unguided or wireless transmission uses antennas to radiate signals through the air across a variety of frequency bands for applications like radio, TV, satellite, and infrared transmission.
Unguided media uses electromagnetic waves to transmit signals without physical conductors. This is known as wireless communication. Signals can travel through ground propagation, sky propagation, or line-of-sight propagation. The electromagnetic spectrum used for wireless communication ranges from 3 kHz to 900 THz. Unguided signals include radio waves, microwaves, and infrared waves, which propagate differently and have different applications.
This document defines various types of computer networks and networking concepts. It begins by defining what a computer network is. It then lists and briefly describes different types of networks including personal area networks, local area networks, wireless local area networks, campus area networks, metropolitan area networks, wide area networks, and storage area networks. It also discusses network topologies such as bus, star, ring, mesh, tree, and hybrid topologies. Finally, it provides an overview of the seven-layer OSI model.
Network transmission involves sending signals over a medium to transmit information between nodes. There are two main types of signals: analog signals where voltage varies continuously and digital signals composed of discrete positive and zero voltages. Transmission can be unidirectional (simplex), allow communication in one direction at a time (half-duplex), or allow simultaneous bidirectional communication (full-duplex). Multiplexing allows multiple signals to travel together over one medium by separating them into logical subchannels. Wireless transmission uses infrared or radio frequency waves to transmit over the air without cables.
This document discusses communication media and data transmission. It covers topics such as analog and digital signals, transmission basics, networking media like coaxial cable, twisted-pair cable, fiber-optic cable, and wireless transmission methods. It compares different media types and provides an overview of concepts like throughput, bandwidth, latency, attenuation, and noise. It also discusses topics like data modulation, transmission direction, multiplexing, and the physical layer standards for Ethernet networks.
A computer network connects devices using communication links. It allows for simultaneous communication and sharing of bandwidth between connected devices sending signals in either direction. There are different types of networks including personal area networks covering a single person, local area networks spanning a building or campus, metropolitan area networks covering multiple cities, and wide area networks spanning countries or continents. Networks rely on protocols that define rules for communication and different hardware technologies for data transmission, including broadcast links that send packets to all machines and point-to-point links that connect individual pairs of machines.
This document discusses different types of transmission media, including their characteristics and applications. It covers both guided media like twisted pair, coaxial cable, and optical fiber, as well as unguided or wireless transmission using radio frequencies, microwaves, and satellites. Key points discussed include the factors that determine transmission quality like bandwidth and interference, the advantages of higher bandwidth and fiber optics, and how different media are suited for various uses from local networks to long-distance trunks based on their data rates and transmission distances.
This document discusses various types of transmission media, including guided media like twisted pair, coaxial cable, and optical fiber, as well as wireless transmission using microwave frequencies and antennas. It covers topics like the characteristics, bandwidth, and impairments of different media, as well as wireless propagation methods like ground wave, sky wave, and line of sight transmission and the effects of multipath interference and free space loss.
The document discusses various topics related to transmission media and the physical layer of the OSI model. It describes guided media like twisted pair cable, coaxial cable, and fiber optic cable. It also discusses unguided transmission using radio waves and microwaves. It explains how signals are transmitted over different media and modulation techniques. It provides details on telephone systems, multiplexing, and how fiber optic networks have replaced older copper networks.
A virtual LAN (VLAN) allows geographically dispersed network nodes to communicate as if they were on the same physical network by logically grouping nodes. A switch that supports VLANs allows the administrator to group specific switch ports together in a VLAN. Data passed between these ports will be isolated from other switch ports. Wired media like twisted pair wire, coaxial cable, and fiber optic cable can be used to physically connect network nodes, with each having advantages and disadvantages regarding attributes like noise absorption, bandwidth, and security.
Communication channels can be either guided (wired) or unguided (wireless) and are used to transmit data between a transmitter and receiver. Guided channels include twisted pair cables, coaxial cables, and optical fibers which have different bandwidth and transmission properties. Unguided channels include terrestrial microwave, satellite, and broadcast radio which propagate signals through the air. The type of channel used depends on factors like bandwidth needs, data rate, distance, and number of receivers.
Transmission media enable computers and other devices to communicate by transmitting signals carrying information. There are two main types: guided media, which uses physical paths like cables, and unguided media, which transmits electromagnetic waves through air. Characteristics of transmission media that impact communication quality include bandwidth, interference levels, and transmission impairments like attenuation and distortion. Common guided media include twisted pair, coaxial, and fiber optic cables, while common unguided media include radio, microwave, and satellite transmissions. The choice of transmission medium depends on factors like data transmission needs, costs, and installation considerations.
Guided transmission media uses cabling to bind data signals, also known as bound media. Types include open wire, twisted pair, coaxial cable, and optical fiber. Unguided media transmits signals as electromagnetic waves via radio waves, microwaves, or infrared light. It can propagate through the ground, sky, or line-of-sight. The electromagnetic spectrum is divided into bands like VLF, LF, MF, HF, VHF, UHF, SHF, and EHF that determine the propagation method and applications.
Communication – Basic process of exchanging information from one location (source) to destination (receiving end).
Refers – process of sending, receiving and processing of information/signal/input from one point to another point.
Electronic Communication System – defined as the whole mechanism of sending and receiving as well as processing of information electronically from source to destination.
Example – Radiotelephony, broadcasting, point-to-point, mobile communications, computer communications, radar and satellite systems.
A communication channel is a medium through which information is transmitted between two points. It can be either guided or unguided. Guided channels use physical transmission media like twisted pair cables, coaxial cables, and fiber optic cables to transmit signals. Unguided channels transmit signals through the air without physical connections, using technologies like microwaves, communication satellites, radio broadcasts, and cellular networks. Communication channels are evaluated based on their bandwidth, or how much data they can carry per unit of time. Fiber optic cables provide the highest bandwidth and fastest transmission speeds of all communication channel types.
This document discusses different types of data transmission media including twisted pair wire, coaxial cable, microwave systems, communication satellites, and optical fibers. It provides details on each medium, describing their basic components, how data is transmitted through each one, advantages, limitations and typical applications. The key transmission media discussed are twisted pair wire for short distance digital transmission, coaxial cable for longer phone and cable lines, microwave systems for line-of-sight transmission, and optical fibers which can transmit data at very high speeds over long distances with no signal loss.
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Gaelic Telecom, doing business as imagine, is:
- The largest Irish-owned telecommunications operator in Ireland.
- Generates over €100 million in annual revenues while maintaining a debt-free, cash-positive position.
- Serves over 115,000 customers and growing, including 80,000 broadband customers and 15,000 business customers.
Transmission media are the means by which data is transmitted over long distances. Common transmission media include guided media like coaxial cable, twisted pair cable, and fiber optic cable as well as unguided or wireless media that transmit signals through air like radio waves, microwaves, and infrared. Each type of transmission medium has its own characteristics and applications. For example, coaxial cable provides good bandwidth and noise immunity but is more expensive than twisted pair cable. Fiber optic cable has the highest bandwidth but requires specialized equipment. Wireless transmission uses electromagnetic signals of varying frequencies that propagate through the air. [/SUMMARY]
This document discusses different types of transmission media used for data communication. It describes guided media like twisted pair wires, coaxial cables, and optical fibers. It also covers wireless or unguided media such as terrestrial microwave, satellite microwave, broadcast radio, and infrared. For each medium, it provides details on characteristics, advantages, disadvantages, and applications. The key factors that affect the quality of a transmission medium are its bandwidth, interference levels, and transmission impairments. Optical fiber has the highest bandwidth capacity but was initially more expensive over short distances.
1. The document discusses various wireless transmission methods including radio transmission, microwave transmission using terrestrial or satellite systems, and infrared transmission.
2. It provides details on how wireless communication systems work by modulating, amplifying and radiating a carrier signal using an antenna, which can then be received by another antenna tuned to the same frequency.
3. The key types of wireless transmissions are described as direct line-of-sight waves, ground-based surface waves that follow the earth's curvature, and skywaves that are reflected by the ionosphere for long distance propagation.
There are two main types of transmission media: guided and unguided. Guided media like twisted pair cable and coaxial cable have a physical path that signals travel along, while unguided media like wireless transmission propagate through free space. Key factors that determine the performance of a transmission medium include its bandwidth, data rate, distance capabilities, and susceptibility to interference. Common guided media include twisted pair, coaxial cable, and optical fiber, each with their own characteristics and applications for voice, data, and video transmission. Unguided or wireless transmission uses antennas to radiate signals through the air across a variety of frequency bands for applications like radio, TV, satellite, and infrared transmission.
Unguided media uses electromagnetic waves to transmit signals without physical conductors. This is known as wireless communication. Signals can travel through ground propagation, sky propagation, or line-of-sight propagation. The electromagnetic spectrum used for wireless communication ranges from 3 kHz to 900 THz. Unguided signals include radio waves, microwaves, and infrared waves, which propagate differently and have different applications.
This document defines various types of computer networks and networking concepts. It begins by defining what a computer network is. It then lists and briefly describes different types of networks including personal area networks, local area networks, wireless local area networks, campus area networks, metropolitan area networks, wide area networks, and storage area networks. It also discusses network topologies such as bus, star, ring, mesh, tree, and hybrid topologies. Finally, it provides an overview of the seven-layer OSI model.
Network transmission involves sending signals over a medium to transmit information between nodes. There are two main types of signals: analog signals where voltage varies continuously and digital signals composed of discrete positive and zero voltages. Transmission can be unidirectional (simplex), allow communication in one direction at a time (half-duplex), or allow simultaneous bidirectional communication (full-duplex). Multiplexing allows multiple signals to travel together over one medium by separating them into logical subchannels. Wireless transmission uses infrared or radio frequency waves to transmit over the air without cables.
This document discusses communication media and data transmission. It covers topics such as analog and digital signals, transmission basics, networking media like coaxial cable, twisted-pair cable, fiber-optic cable, and wireless transmission methods. It compares different media types and provides an overview of concepts like throughput, bandwidth, latency, attenuation, and noise. It also discusses topics like data modulation, transmission direction, multiplexing, and the physical layer standards for Ethernet networks.
A computer network connects devices using communication links. It allows for simultaneous communication and sharing of bandwidth between connected devices sending signals in either direction. There are different types of networks including personal area networks covering a single person, local area networks spanning a building or campus, metropolitan area networks covering multiple cities, and wide area networks spanning countries or continents. Networks rely on protocols that define rules for communication and different hardware technologies for data transmission, including broadcast links that send packets to all machines and point-to-point links that connect individual pairs of machines.
This document discusses different types of transmission media, including their characteristics and applications. It covers both guided media like twisted pair, coaxial cable, and optical fiber, as well as unguided or wireless transmission using radio frequencies, microwaves, and satellites. Key points discussed include the factors that determine transmission quality like bandwidth and interference, the advantages of higher bandwidth and fiber optics, and how different media are suited for various uses from local networks to long-distance trunks based on their data rates and transmission distances.
This document discusses various types of transmission media, including guided media like twisted pair, coaxial cable, and optical fiber, as well as wireless transmission using microwave frequencies and antennas. It covers topics like the characteristics, bandwidth, and impairments of different media, as well as wireless propagation methods like ground wave, sky wave, and line of sight transmission and the effects of multipath interference and free space loss.
The document discusses various topics related to transmission media and the physical layer of the OSI model. It describes guided media like twisted pair cable, coaxial cable, and fiber optic cable. It also discusses unguided transmission using radio waves and microwaves. It explains how signals are transmitted over different media and modulation techniques. It provides details on telephone systems, multiplexing, and how fiber optic networks have replaced older copper networks.
A virtual LAN (VLAN) allows geographically dispersed network nodes to communicate as if they were on the same physical network by logically grouping nodes. A switch that supports VLANs allows the administrator to group specific switch ports together in a VLAN. Data passed between these ports will be isolated from other switch ports. Wired media like twisted pair wire, coaxial cable, and fiber optic cable can be used to physically connect network nodes, with each having advantages and disadvantages regarding attributes like noise absorption, bandwidth, and security.
Communication channels can be either guided (wired) or unguided (wireless) and are used to transmit data between a transmitter and receiver. Guided channels include twisted pair cables, coaxial cables, and optical fibers which have different bandwidth and transmission properties. Unguided channels include terrestrial microwave, satellite, and broadcast radio which propagate signals through the air. The type of channel used depends on factors like bandwidth needs, data rate, distance, and number of receivers.
Transmission media enable computers and other devices to communicate by transmitting signals carrying information. There are two main types: guided media, which uses physical paths like cables, and unguided media, which transmits electromagnetic waves through air. Characteristics of transmission media that impact communication quality include bandwidth, interference levels, and transmission impairments like attenuation and distortion. Common guided media include twisted pair, coaxial, and fiber optic cables, while common unguided media include radio, microwave, and satellite transmissions. The choice of transmission medium depends on factors like data transmission needs, costs, and installation considerations.
Guided transmission media uses cabling to bind data signals, also known as bound media. Types include open wire, twisted pair, coaxial cable, and optical fiber. Unguided media transmits signals as electromagnetic waves via radio waves, microwaves, or infrared light. It can propagate through the ground, sky, or line-of-sight. The electromagnetic spectrum is divided into bands like VLF, LF, MF, HF, VHF, UHF, SHF, and EHF that determine the propagation method and applications.
Communication – Basic process of exchanging information from one location (source) to destination (receiving end).
Refers – process of sending, receiving and processing of information/signal/input from one point to another point.
Electronic Communication System – defined as the whole mechanism of sending and receiving as well as processing of information electronically from source to destination.
Example – Radiotelephony, broadcasting, point-to-point, mobile communications, computer communications, radar and satellite systems.
A communication channel is a medium through which information is transmitted between two points. It can be either guided or unguided. Guided channels use physical transmission media like twisted pair cables, coaxial cables, and fiber optic cables to transmit signals. Unguided channels transmit signals through the air without physical connections, using technologies like microwaves, communication satellites, radio broadcasts, and cellular networks. Communication channels are evaluated based on their bandwidth, or how much data they can carry per unit of time. Fiber optic cables provide the highest bandwidth and fastest transmission speeds of all communication channel types.
This document discusses different types of data transmission media including twisted pair wire, coaxial cable, microwave systems, communication satellites, and optical fibers. It provides details on each medium, describing their basic components, how data is transmitted through each one, advantages, limitations and typical applications. The key transmission media discussed are twisted pair wire for short distance digital transmission, coaxial cable for longer phone and cable lines, microwave systems for line-of-sight transmission, and optical fibers which can transmit data at very high speeds over long distances with no signal loss.
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Gaelic Telecom, doing business as imagine, is:
- The largest Irish-owned telecommunications operator in Ireland.
- Generates over €100 million in annual revenues while maintaining a debt-free, cash-positive position.
- Serves over 115,000 customers and growing, including 80,000 broadband customers and 15,000 business customers.
Computer networks have become part of our everyday lives. We use them to take cash from the local ATM. Whenever we send email or browse the Web, we rely on the world’s largest computer network, the Internet, to be our electronic mailman. Telemarketers, usually during dinner hour, use computer networks to sell us their wares. Our cable television stations rely on computer networks to transport programs onto our TV screens. What is a compelling example of their presence in our lives? Without computer networks, our cellular phone is little more than a battery powering-up a meaningless screen. Read more.........
Sally Frederick Tudor offers computer networking and web design services in Houston, Texas. She graduated with high honors from ITT Technical Institute in Webster and has experience installing, updating, and troubleshooting computer systems. Satisfied customers provide referrals that help sustain her business.
This document summarizes key concepts in digital image processing, including:
1) Image processing transforms digital images for viewing or analysis and includes image-to-image, image-to-information, and information-to-image transformations.
2) Image-to-image transformations like adjustments to tonescale, contrast, and geometry are used to enhance or alter digital images for output or diagnosis.
3) Image-to-information transformations extract data from images through techniques like histograms, compression, and segmentation for analysis.
4) Information-to-image transformations are needed to reconstruct images for output through techniques like decompression and scaling.
Introduction to digital image processing, image processing, digital image, analog image, formation of digital image, level of digital image processing, components of a digital image processing system, advantages of digital image processing, limitations of digital image processing, fields of digital image processing, ultrasound imaging, x-ray imaging, SEM, PET, TEM
1) Digital image processing involves improving, restoring, compressing, segmenting, and recognizing digital images. It has applications in industry, medicine, traffic control, entertainment, and more.
2) The origins of digital image processing date back to the 1920s in newspaper printing, but it developed significantly with the space program in the 1960s and medical CT scans in the 1970s.
3) A digital image processing system typically involves image acquisition, storage, processing, and display. Low-level processes improve image quality while mid- and high-level processes extract attributes and recognize objects.
This document summarizes a presentation on image processing. It introduces image processing and discusses acquiring images in digital formats. It covers various aspects of image processing like enhancement, restoration, and geometry transformations. Image processing techniques discussed include histograms, compression, analysis, and computer-aided detection. Color imaging and different image types are also introduced. The document concludes with mentioning some common image processing software.
This presentation discusses digital image processing. It begins with definitions of digital images and digital image processing. Digital image processing focuses on improving images for human interpretation and processing images for machine perception. The history of digital image processing is then reviewed from the 1920s to today. Key examples of applications like medical imaging, satellite imagery, and industrial inspection are provided. The main stages of digital image processing are outlined, including image acquisition, enhancement, restoration, segmentation, and compression. The document concludes with an overview of a system for automatic face recognition using color-based segmentation.
Transmission media carry data from sender to receiver using electrical or electromagnetic signals through various cables or waves. There are two main types of transmission media: wired (guided) media like twisted pair cables, coaxial cables, and fiber optic cables; and wireless (unguided) media like radio waves, microwaves, and satellite transmissions. Different transmission media have different characteristics, such as bandwidth, that determine their suitability for various data transmission applications and distances.
The document discusses different types of transmission media including guided media like twisted-pair cable, coaxial cable, and optical fiber as well as unguided or wireless media. It describes the basic characteristics of each type of media such as how they transmit signals, common applications, advantages, and disadvantages. Key topics covered include how different electromagnetic frequencies propagate through different parts of the atmosphere, common standards and specifications for different cable types, and factors that determine the range and bandwidth of each transmission medium.
Communication channel and networktechnologies.pdfmouizakhan4
1) The document discusses various topics related to telecommunication systems including communication channels, signals, and network components. It describes how speech signals are converted to electrical forms and transmitted over channels.
2) The communication channel acts as a conduit between the transmitter and receiver. Impairments like noise, attenuation and bandwidth limitations can degrade signals during transmission.
3) A communication system requires a transmitting device, transport mechanism, and receiving device to effectively transfer information. Networks facilitate communication between users across geographical boundaries using various transmission media and standards.
The document discusses different types of transmission media used for telecommunications including guided media like twisted-pair cable, coaxial cable, and optical fiber as well as unguided or wireless media. It describes the basic characteristics of each type of medium, how they transmit signals, their applications, advantages and disadvantages.
This document discusses different types of transmission media, including guided and unguided media. It describes four types of guided media: open wire, twisted pair, coaxial cable, and fiber optic cable. Twisted pair cable uses two insulated copper wires twisted together to reduce interference. Coaxial cable has an inner conductor surrounded by insulation and an outer shield. Fiber optic cable uses thin glass fibers to carry light signals. It also discusses four types of unguided or wireless media: radio waves, microwaves, infrared, and visible light. Radio waves can travel long distances while microwaves use line-of-sight transmission between towers. Infrared is used for short-range indoor communication.
This document provides an overview of fundamental concepts in telecommunication systems and transmission. It begins with definitions of telecommunication networks and the basic purpose of transmitting information from one user to another. It then discusses different types of transmission media that can be used including twisted pair cable, coaxial cable, and fiber optics. The document also covers elements of transmission systems including modulation, line coding, and conversion of voice signals to digital. It introduces concepts of PDH and SDH digital carrier systems, including E1 and STM-1 frame structures. In summary, the document provides foundational information on telecommunication networks, transmission media, and digital signal transmission standards.
This document discusses and compares different types of transmission media, including guided and unguided media. Guided media includes twisted pair cables, coaxial cables, and optical fiber cables. Unguided media includes radio waves, microwaves, and infrared waves. Each type of media has different characteristics, performance capabilities, and applications. Optical fiber provides the highest bandwidth and data transmission rates, while being immune to interference, but is also the most expensive.
Unit 5 process data transmission standards and buseshiya123jes
1) There are three transmission modes - simplex, half duplex, and full duplex. Simplex allows transmission in one direction, half duplex allows transmission in either direction but not simultaneously, and full duplex allows simultaneous transmission in both directions.
2) Transmission media are either guided (wired) using cables like twisted pair, coaxial, and fiber optic, or unguided (wireless) using radio waves, microwaves, and infrared. Guided media uses conductors while unguided uses electromagnetic waves without conductors.
3) Common transmission standards and technologies described include twisted pair cable, coaxial cable, fiber optic cable, radio waves, microwaves, and infrared waves. Each has their own advantages
The document is a presentation submitted by Harpreet Kaur on data communications. It contains information on various topics related to data communications including an introduction to data communication, components of data communication such as sender, receiver, message, transmission medium and protocol. It also discusses data flow modes, analog and digital signals, types of transmission media including guided media such as coaxial cable, twisted pair cable and fiber optic cable, and unguided media. Finally, it covers networking devices such as modem, hub, switch and router.
This document discusses different types of transmission media, including wired and wireless options. Wired transmission uses cables like twisted pair, coaxial, and optical fiber cables to transmit data through physical pathways in a bounded manner. Wireless transmission methods like radio waves, microwaves, infrared, Bluetooth, and satellites transmit data without cables by utilizing different frequencies. Each transmission media has advantages and limitations regarding speed, reliability, range, bandwidth, and susceptibility to interference.
Wired transmission media includes twisted pair cables, coaxial cables, and optical fiber cables. It provides physically constrained signal propagation with little interference. Wired networks are highly compatible, reliable, secure, and can transmit data at faster speeds compared to wireless networks. However, wireless networks have become more prevalent in everyday devices due to their convenience over wired networks.
Transmission lines guide electrical energy from one point to another. They have two ends - an input end connected to the source, and an output end connected to the load. Common types of transmission lines include twisted pair, coaxial cable, and optical fiber. Twisted pair comes in unshielded and shielded variants, with shielded providing better protection against interference. Coaxial cable carries signals of higher frequencies than twisted pair. Optical fiber uses light pulses to transmit data over long distances at high speeds. Wireless transmission uses electromagnetic waves like radio waves, microwaves, and infrared to transmit data through the air without a physical medium.
The Presentation describes about the Transmission media and in detail about coaxial cable,Twisted pair, Fiber optics, Power lines and their comparisons
1. Guided media uses cabling to guide data signals along a specific path, including twisted pair cable, coaxial cable, and optical fiber.
2. Unguided or wireless media transmits electromagnetic signals through free space without cabling, including radio waves, microwaves, and infrared waves.
3. Common examples of wireless transmission media are WiFi networks using radio waves, cellular networks and satellite TV using microwaves, and TV remotes using infrared signals.
This document summarizes transmission media, which is the means of transmitting data from one place to another. It discusses two main types: guided media, which uses physical conductors like twisted pair, coaxial cable, and optical fiber; and unguided media, which transmits electromagnetic signals through air like radio waves, microwaves, infrared, and lasers. Each type of media is then described in 1-2 sentences regarding its characteristics and applications.
Guided media uses cabling to guide data signals along a specific path. The three main types of guided media are twisted pair cable, coaxial cable, and optical fiber. Unguided or wireless media transmits electromagnetic signals through free space without a physical medium. Common types of wireless media include radio waves, microwaves, and infrared waves.
Communication and networking for class 12.pptxnesia7885
Network and Communication refer to the interconnected systems and devices that enable the transfer of data and information between various endpoints. The main components of a network and communication system include hardware devices such as computers, routers, switches, and modems, and software protocols that govern the flow of data between these devices.
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The workshop was held on the DMA Conference in Vienna June 2024.
Understanding User Behavior with Google Analytics.pdfSEO Article Boost
Unlocking the full potential of Google Analytics is crucial for understanding and optimizing your website’s performance. This guide dives deep into the essential aspects of Google Analytics, from analyzing traffic sources to understanding user demographics and tracking user engagement.
Traffic Sources Analysis:
Discover where your website traffic originates. By examining the Acquisition section, you can identify whether visitors come from organic search, paid campaigns, direct visits, social media, or referral links. This knowledge helps in refining marketing strategies and optimizing resource allocation.
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Gain a comprehensive view of your audience by exploring demographic data in the Audience section. Understand age, gender, and interests to tailor your marketing strategies effectively. Leverage this information to create personalized content and improve user engagement and conversion rates.
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Learn how to measure user interaction with your site through key metrics like bounce rate, average session duration, and pages per session. Enhance user experience by analyzing engagement metrics and implementing strategies to keep visitors engaged.
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Understand the importance of conversion rates and how to track them using Google Analytics. Set up Goals, analyze conversion funnels, segment your audience, and employ A/B testing to optimize your website for higher conversions. Utilize ecommerce tracking and multi-channel funnels for a detailed view of your sales performance and marketing channel contributions.
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Meet up Milano 14 _ Axpo Italia_ Migration from Mule3 (On-prem) to.pdfFlorence Consulting
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Instagram has become one of the most popular social media platforms, allowing people to share photos, videos, and stories with their followers. Sometimes, though, you might want to view someone's story without them knowing.
2. BY
YASHWANT IMBA/40534/11
PRASOON KUMAR IMBA/40535/11
AMIT KESARWANI IMBA/40547/11
AKASH MISHRA IMBA/40550/11
SHUBHAM IMBA/40551/11
ASHISH KR. SINHA IMBA/40555/11
3. NETWORKING
DATA COMMUNICATION:
CONCEPTS
COMPONENTS
DATA MEASUREMENT
TRANSMISSION MODE
TRANSMISSION MEDIA
TRANSMISSION
METHODS
MODULATION
TECHNIQUES
COMPUTER NETWORK
TYPES: LANs & WANs
INTRANET & EXTRANET
TOPOLOGIES
PROTOCOL & THE OSI
MODEL
NETWORK DEVICES
4. What is Data Communication?
DATA COMMUNICATION: CONCEPTS
Data communication is the exchange of data between 2 devices via
some form of wired or wireless transmission medium.
It includes the transfer of data, methods of transfer, and the
preservation of data during the transfer process.
The hardware and software, that facilitate data communication,
taken together forms a communication system.
To initiate data communication, the communicating devices should be
a part of an existing communication system.
For effective data communication, the following 3 fundamental
characteristics should be considered:-
1) Delivery
2) Accuracy
3) Timeliness
5. DATA COMMUNICATION: CONCEPTS
PROTOCPL PROTOCPL
Step-1
Step-2
…..
…..
…..
Step-7
Data communication
components:-
5 basic components in data
communication system
are:
1. Message
2. Sender
3. Receiver
4. Medium
5. Protocol
Step-1
Step-2
…..
…..
…..
Step-7
MESSAGE
SENDER
TRANSMISSION
MEDIUM RECEIVER
6. Measurement of Data :-
The rate of data transmission is measured in Bandwidth.
Bandwidth refers to the maximum volume of information
that can be transferred over any communication medium.
The more the information needed to transmit in a given
period, the more the bandwidth required.
On digital circuits, bandwidth is measured in bits per
second (bps). 1,000 bps = 1 Kbps.
D
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7. The level of Bandwidths falls into 3 categories:
1) Narrow Band
There is a single transmission channel of 64Kbps or less.
There can be a number of 64Kbps transmission (N*64Kbps)
but not more than 1.544Mbps (also called T1 line).
2) Wide Band
Bandwidth capacity lies between 1.544Mbps – 45Mbps.
3) Broad Band
The bandwidth capacity is equal to 45Mbps or a T3 line.
D
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Measurement of Data :-
8. Data Transmission Mode :-
Data transmission mode refers to the direction
of signal flow between 2 linked devices. There
are 3 types of transmission modes:
Simplex
Half -
Duplex
Full –
Duplex
9. SIMPLEX
DIRECTION OF DATA
Simplex transmission is unidirectional, i.e., the
information flows in one direction across the circuit,
with no capability to support response in the other
direction.
Only one of the communicating devices transmits
information, the other can only receive it. E.g.- TV
communication.
10. HALF- DUPLEX
DIRECTION OF DATA AT T1
DIRECTION OF DATA AT T2
In Half-Duplex mode, each communicating device
can receive and transmit information, but not at the
same time.
When one device is sending, the other can only
receive at that point of time. E.g. – wireless handsets
(generally used by military personnel).
11. FULL- DUPLEX
DIRECTION OF DATA AT ALL TIME
It is also known as simply the Duplex mode. It allows
both communicating devices to transmit and receive
data simultaneously.
E.g. – Telephone network.
12. DATA COMMUNICATION: CONCEPTS
Transmission Media refers to
the physical media through
which signals are transmitted.
It can be wired or wireless.
The signal transmitted from
one device to another is
through Electromagnetic
waves.
An electromagnetic signal is
the combination of electric and
magnetic fields, vibrating in
conjugation with each other.
EM signals include power,
voice, radio waves, infrared
light, visible light, UV light, X-rays,
Gamma-rays. All these
together constitute an EM
spectrum.
These signals can travel
through vacuum, air or any
other transmission medium.
Media
Guided
Media
Open Wire
Twisted
Pair
UTP Cable
STP Cable
Coaxial
Wire
Optical
Fiber
Unguided
Media
E.g.-Radio
Frequency
Propagation
Ground
Wave
Ionospheric
Propagation
Line of Sight
E.g.-FM
Radio
E.g.-
Microwave
E.g.-
Satellite
Data
Transmission
Media
13. Guided Media (Bound Media) – Wired Media
Guided Transmission Media use a cabling system that guide the data signals along
a specified path through the cables. Hence they are also called bound media. 4
basic types are- Open Wire, Coaxial Wire, Twisted Pair, and Optical Fiber.
Type 1- Open Wire
Open wire is used to
transmit power through
wires strung along
power poles.
Not recommended for
long data transmission.
The reasons are:-
1. Loss of energy
problem.
2. It can easily be tapped.
3. No shielding from
noise interference.
Type 2- Coaxial Wire
Coaxial cables have a single
central conductor, which is
made up of solid wire
(usually Cu).
Features:-
1. It is very robust and is
used in Cable TV network.
2. It offers a bandwidth of
10Mbps.
14. Type 3- Twisted Pair
Pairs of wires are twisted together which are surrounded by an insulating material and an
outer layer called jacket. They are twisted to reduce noise.
Each pair consist of wire, for receiving data signal, and a wire for transmitting data signal.
Like open wire, these also transmit data in the form of current.
Twisted pairs are used in a short distance communication (less than 100m) and they are
available in 2 forms:- unshielded twisted pair (UTP) & shielded twisted pair (STP) cables.
UTP:-
STP:-
It is the most common
STP cable has a metal foil
type of telecommunication
that covers each pair of
medium in use today.
insulated conductors.
It is most suited for both
data & voice transmission
The metal foil prevents
and hence commonly used
infiltration of EM noise.
in telephone systems.
The shield also helps to
They have a transmission
eliminate crosstalk.
speed of up to 9600bps.
15. Type 4- Optical Fiber
Optical fiber consists of thin glass fibers that
can carry information in the form of visible light,
unlike coaxial wire & twisted pair which carry
signal as electrical current.
The main components of an optical fiber are:
Core- it is a very narrow stand of glass.
Cladding- it is a concentric layer of glass around the
core.
Jacket- it is a protective coating of plastic which
covers the cladding.
Optical fiber works on the principle that the
core refracts the light and the cladding reflects the
light; the core refracts the light and guides the
light along its path. Whereas the cladding reflects
any light back into the core and stops it from
escaping through the medium. This principle is
called TOTAL INTERNAL REFLECTION.
The light pulses, which can be carried over long
distances via optical fiber cable, carry information.
16. Type 4- Optical Fiber
Advantages of optical fiber:-
1. Since transmission is light-based rather
than electricity, it is immune to noise
interference.
2. Transmission distance is greater than
other guided media because of les
signal attenuation (degradation of
quality over distance).
3. It is more secure because cable can not
be tapped.
4. They are smaller and lighter than
Copper wire and are free from
corrosion as well.
5. Fiber optic offers, by far, the greatest
bandwidth of any transmission system
Disadvantages of optical fiber:-
1. Fiber optic is expensive as it is costly to
produce, maintain, and install.
2. They are more fragile as fiber optic
tends to break easily as compared to
Copper wire.
17. Unguided Media – Wireless Media
Unguided Transmission Media is data signals that flow through the air.
They are not bound to a fixed channel to flow.
One of the most common unguided media of transmission is- radio frequency
propagation.
Radio frequency propagation: In RF propagation, the signal is carried over
carrier Type waves 1-Open (waves Wire
which carry signals over them), which have frequencies in the
range of radio frequency spectrum.
There are 3 types of RF propagation:
1. Ground wave propagation
2. Ionospheric propagation
3. Line of sight propagation
1. Ground wave propagation:
It follows the curvature of the
earth
They have carrier frequencies of
up to 2MHz
E.g.- AM Radio
Type 2- Coaxial Wire
2. Ionospheric propagation:
The signal waves bounces off the
earth’s ionosphere layer
Frequency range is 30-85MHz
18. 3. Line of Sight Propagation-
It transmits exactly in the line of sight .
The receiving station must be in the view of transmitting
station.
Typically the line of sight due to the earth’s curvature is
50km to the horizon
E.g.- FM Radio, Microwave, & Satellite.
Microwave:
•Microwave transmission is line of sight
transmission.
•The transmit station must be in visible
contact with the receiving station.
•Since the line of sight due to earth’s
curvature is only 50 km to the horizon,
repeater stations must be placed so the
data signal can travel farther than the
distance limit.
Satellite:
•Satellites are set in geostationary orbits which are
placed 36,000 km above the earth’s surface, and
rotates in synchronization to earth.
•The communication is carried through uplinks and
downlinks. The uplink transmits the data to the
satellite and downlink receives the data from the
satellite.
•Uplinks and downlinks are also called earth’s
stations because they are located on earth.
•The area shadowed by the satellite in which the data
can be transferred is called the footprint.
19. DATA COMMUNICATION: CONCEPTS
Data Transmission Methods :-
Any information to be transmitted from one communicating device to
another, by any media (wired or wireless), is first transformed into
electromagnetic signals. Information is transmitted by 2 methods:
ANALOG & DIGITAL.
Analog signals:
An analog signal is a continuous waveform
that changes smoothly over time.
Most fundamental form of an analog signal
is- the Sine Wave.
Sine waves have 3 main characteristics:
amplitude, frequency, & wavelength.
Digital Signals:
Digital data is the data stored in the
form of 0 and 1. When a signal is at high
point, its value is 1 and when it is low, its
value is 0.
For data to be processed by computer
or any digital device, they are converted
into digital (machine readable) formats.
1 1 1
0 0
t
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e Digital Signal Wave
20. Modulation Techniques
Before an information is transmitted in a wide communication system, the information
or modulating signals are superimposed on a carrier signal, which propagates by means
of an electromagnetic wave. This process is called modulation.
The carrier waves carry the signals to travel over ling distances.
Generally, there are 2 forms of modulation- amplitude & frequency.
Amplitude Modulation:
DATA COMMUNICATION:
In this modulation, the frequency
of the carrier remains the same,
only the amplitude changes to
follow variation in the signal.
CONCEPTS
Frequency Modulation:
In this modulation, the amplitude of
the carrier remains the same. The
frequency change to follow
variation in the signal.
21. COMPUTER NETWORK
What is a Computer Network ?
A computer network is simply two or more computers
connected together to share information and
resources.
The network connection can be through some wired
media such as telephone lines, coaxial cables, or
through wireless media such as satellite links, radio,
an/or some other communication technique.
The purpose of connection is to share information an
resources.
22. C
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TYPES OF NETWORKS
Broadly there are two types of network on the basis of various factors like the size of
the network, the distance it covers, and the type of link used in the interconnection:
LAN- Local Area Network
WAN- Wide Area Network
LAN:
A LAN is a computer network that spans
only a small geographical area, such as
an office, home or building.
Of the many computers connected, one
computer is designated as the file server,
which stores all the software that controls
the network along with the software that
can be shared by the computers attached
to the network. Other computers
connected to the file server are called
workstations.
Most LANs use cable – connectivity.
Bandwidth- 10 to 100 Mbps.
The cost of setting a LAN is low.
WAN:
It is a connection of multiple LANs
which are geographically separate.
They span over a large geographical
area such as cities, states, countries or
even the whole world.
MANs use long-range
communication technologies such as
telephone lines, satellite links, etc.
Transmission speed is much higher as
compared to LAN.
Cost of setting up a WAN is very high.
There are several types of WAN:
Metropolitan area network(MAN)
Public Access Network(PAN)
Value Added Network(VAN)
Virtual Private Network(VPN)
INTERNET (largest WAN in existence)
23. INTRANET TYPES OF
NETWORKS
INTRANET & EXTRANET
EXTRANET
Intranet – An intranet is a private LAN designed for use by
everyone within an organization. An intranet might consist of an
internal e-mail system, a message board and one or more Web
site portals that contain company news, forms, and personnel
information.
Access to an intranet’s web site is restricted by a firewall.
Extranet – a network that connects people within your
company with people who are outside your company--all within
a secure, password-protected network that can be accessed
from anywhere.
C O M P U T E R N E T W O R K
24. EXAMPLE OF FIREWALL
Firewalls are systems that establish access control policies
among networks.
They can block information from entering a network or from
getting out of that network, they can permit different users to
perform different kinds of operations, according to the user's
authorizations.
C O M P U T E R N E T W O R K
25. BENEFITS OF A NETWORK
Information sharing: Authorized users can use other
computers on the network to access and share information and
data. This could include special group projects, databases, etc.
Hardware sharing: One device connected to a network,
such as a printer or scanner, can be shared by many users.
Software sharing: Instead of purchasing and installing a
software program on each computer, it can be installed on the
server. All of the users can then access the program from a single
location.
Collaborative environment: Users can work
together on group projects by combining the power and
capabilities of diverse equipment.
26. RISKS OF NETWORK COMPUTING
The security of a computer network is challenged
everyday by:
• Equipment malfunctions
• System failures
Note: equipment malfunctions and system failures
may be caused by natural disasters such as floods,
storms, or fires, and electrical disturbances
• Computer hackers
• Virus attacks
27. Network Topologies
The term topology refers to the way a network is laid out, either
physically or logically.
It can be considered as the network’s shape.
It is the geometric representation of the relationship of all the
links.
There are 5 basic topologies-
Bus
Ring
Star
Tree
Mesh
COMPUTER NETWORK
28. •Connecting to a
computer or peripheral to
a linear bus is easy.
•It requires least amount
of cabling, and hence is
les expensive.
•Entire network shuts
down if there is a failure
in the common bus or
backbone (single cable).
•Heavy traffic can slow
down a bus.
Bus Topology
All stations are connected to a single long cable.
Any station can send a signal along the cable,
which all other stations will receive. Unlike ring
topologies, the cable doesn't close a loop.
29. •It is easy to install and
reconfigure.
•Every computer is given
equal access to the ring.
Hence, no single computer
can monopolise the
network.
•Failure in any cable or
node breaks the loop and
can take down the entire
network.
•Maximum ring length and
number of nodes are
limited.
RING Topology
In ring topology, computers are connected in a
cable-loop.
All messages travel through a ring in the same
direction (clockwise or counterclockwise) until it
reaches its destination.
30. •It is easy to install and wire.
•The network is not disrupted
even if a node fails or is
removed from the network.
•Fault detection and removal
of faulty parts is easier.
•It requires a longer length of
cable.
•If the hub fails, nodes
attached to it are disabled.
•The hub is costly, making the
network expensive as
compared to bus and ring
topology.
STAR Topology
File Server
Computers and devices are connected via a
centralised network component called HUB, which
acts as a central controller.
It uses mostly twisted pair cables. Other cables
are also used.
31. tree Topology It is a combination of linear bus and
•The signal transmission distance
increases as the signal passes through a
chain of hubs.
•It allows for easy expansion of an
existing network.
star topologies.
It consists of groups of star-configured
workstations connected
to a bus backbone cable .
Not every node plugs directly to
the central hub. The majority of
nodes connect to a secondary hub
that in turn is connected to the
central hub.
Each secondary hub in this
topology functions as the
originating point of a branch to
which other nodes connect.
•If the backbone line breaks, the
entire segment goes down.
•It is more difficult to configure
and wire than other topologies.
Secondary Hub
32. •The use of large number of
links eliminates network
congestion.
•If one link becomes unstable,
it does not disable the entire
system.
•The amount of required cabling
is very large.
•As every node is connected to
the other, installation and
reconfiguration is very difficult
•The amount of hardware
required can make this topology
expensive.
MESH Topology
Every node has a point-to-point link to every other
node.
Messages sent on a mesh network can take any of
several possible paths from source to destination.
33. NETWORK / COMMUNICATION PROTOCOLS
A computer protocol is simply a set of rules and procedures for
transmitting data between two or more devices. They define the
manner in which the data communication takes place.
If one computer is sending information to another and they both
follow the same protocol, the message gets through; regardless of what
type of machines they are and on what operating system they are
running.
As long as the machines have software that can manage the protocol,
communication is possible.
• Features determined by the protocol are-
– How the sending device indicates it has finished sending the
message.
– How the receiving device indicates it has received the message.
– The type of error checking to be used.
34. The OSI Model NETWORK/COMMUNICATION PROTOCOLS
Open Systems Interconnection (OSI) is a basic reference model for
communication between 2 end users in a network.
The model lays a framework for the design of network systems that
allow for communication across all types of computer systems.
OSI model is a structure that applies (fully or in parts) for any digital
communication network.
It is a prescription of characterizing and standardizing the functions of
a communication system in terms of abstraction layers.
It consists of separate but related 7 Layers that represent a functional
division of the tasks needed to implement a network. They are- Physical,
Data Link, Network, Transport, Session, Presentation, Application . Each
layer consists of a set of specific protocols.
Similar communication functions are grouped into logical layers. A
layer serves the layer above it and is served by the layer below it.
For example- the 4th layer, which provides error-free
communications across a network, avails the path needed by
applications of 5th layer, while it instructs the 3rd layer to send and
receive packets that make up the contents of that path.
35. Categories of the OSI layer:
NETWORK/COMMUNICATION
The OSI Model PROTOCOLS
These layers deal with application
issues, and are implemented only
in the software.
The highest layer- Application, is
closest to the end user.
These layers handle the data
transport issues.
The Physical and Data-Link layer
are implemented in both hardware
and software.
Network & Transport layers are
implemented only in software.
The lowest layer- Physical layer is
closest to the cabling and places the
information on the cables.
36. Layer Breakdown
Layer 1: Physical
– The physical network hardware, medium.
Layer 2: Data Link
– How data is organized into frames, and how to
transmit those frames. Byte/bit stuffing, checksums.
Layer 3: Network
– How addresses are assigned, and how packets are
transmitted from one end of the network to the
other.
37. Layer Breakdown (cont.)
Layer 4: Transport
– How to reliably transfer data.
Layer 5: Session
– How to start sessions (connections) with remote devices,
machines. (Sockets)
Layer 6: Presentation
– How to represent data. Does int, char replacements.
Layer 7: Application
– How one user-level program requests a connection to another
machine, and how the machine responds.
38. NETWORK
INTERFACE
CARD (NIC)
NETWORK
DEVICES
HUB
REPEATER
BRIDGE
SWITCH
MODEM
ROUTER
GATEWAY
THE NETWORK
DEVICES
INTERCONNECT
INDIVIDUAL
COMPUTERS
AND ENSURE
THAT THEY
COMMUNICATE
EFFICIENTLY
COMPUTER NETWORK
39. NETWORK
INTERFACE
CARD (NIC)
•NIC is the first contact between the machine and the
network. It connects clients, servers and peripherals to
the network via a port.
•They are small circuit boards that can be inserted onto
one of the computer motherboard’s slot.
40. HUB
(connectors)
•A HUB is a small box that connects individual devices on a
network so that they can communicate with one another.
•The hub's major function is to replicate data it receives from
one device attached to it to all others.
•It is also called CONNECTOR, it works on the physical layer
of the OSI model.
41. REPEATER
•A repeater is an electronic device that that operates on
the physical layer of the OSI model.
•Signals that carry information within a network can
travel a fixed distance before attenuation weakens them
enough to be disintegrated. A repeater installed on the
link receives the signal, regenerates it, and sends the
refreshed copy back to the link.
42. SWITCH
•Like a hub, a switch too connects individual devices on
a network so that they can communicate with one
another.
•Switches work on the data link layer of the OSI model.
•They are ‘intelligent’ HUBS. Unlike hubs, network
switches can inspect the data packet as they are
received, determine the source and the destination
device, and forward the packet appropriately.
43. BRIDGE
BRIDGE
•A bridge filters data traffic at a network boundary.
•It reduces the amount of traffic on a LAN by dividing it
into segments.
•It inspects incoming traffic and decides whether to
forward or discard it.
•Bridges operate at the data link layer of the OSI model.
44. ROUTER
Router/firewall
•Routers connect two or more networks and forward data
packets between them.
•A router creates and/or maintains a table, called a ‘routing
table’ that stores the best routes to certain network
destinations.
•Router’s sole aim is to trace the best route for information to
travel.
45. GATEWAY
(PROTOCOL
CONVERTERS)
•Gateways are protocol converters. It accepts the packet
formatted for one protocol and converts the formatted
packet into another protocol.
•It is an internetworking device, which joins two different
network protocols together.
•It works on all the 7 layers of the OSI model.
GATEWAY
46. MODEMS
An illustration of data sent using a modem and a
regular telephone line.
A modem is a device that converts digital data
originating from a terminal or computer, to analog
signals used by voice communication networks such as
the telephone system.
At one end, modems convert the digital pulses to
audible tones and convert audio tones back to digital
pulses at the other.
The word "Modem" stands for:
"Modulator- Demodulator"
47. Transmission speed
Modems are available in different transmission speeds,
which are measured in BPS (bits per second) also called
BAUD rate.
Standard modems speeds: 9600 baud, 14400 baud, 28800
baud, 33600 baud, 56800 baud.
TYPES- Internal/External
Internal modems are electronic cards. An internal modem
is installed in one of the computer's expansion slot.
External modems are fully functioning external devices.
The external modem is connected to a computer using a
serial cable to one of the computer's serial ports, and
draws power from an external power source.
THANK YOU
MODEMS