Thursday 28 April 2011

Types of communication links

There are several types of communication links. Some of them may be already known.
pairs
One of the most common means of communication is a pair of wires, also known as cable. pairs of wires are twisted together in the cable, which is then insulated. pairs of wires are inexpensive. Moreover, they are often used because it is already installed in the building for other purposes or because they are already used in telephone systems. However, they are prone to electrical interference and noise. Noise is something that causes distortions in the signal after it is received. High-voltage equipment, and even the sun can be a source of noise.
Coaxial cables
Known for sending a strong signal, coaxial cable is a shielded cable in the housing. Harness can be laid underground or underwater. These cables can transmit data much faster than the wire pairs and are less prone to interference. These types of cables that carry cable TV in their homes. cable companies are now coming out of Internet services to homes (Cox @ Home is an example of Rhode Island), which use cable lines and providing access much faster than telephone lines can provide.
Fiber Optics
Traditionally, most telephone lines of the data transmitted by electrical wires made of metal, usually copper. These metal wires need to be protected from water and other corrosive substances. Fiber optic technology eliminates this requirement. Instead of using electricity to transmit data, fiber optics uses light. Cables are made of glass fibers, each thinner than a human hair that can direct the beam of light for miles. Fiber-optic cables transmit data faster than some technologies, but the materials are much lighter and cheaper than metal cables. You can also send and receive a wider range of frequencies at one time. The frequency range that the device can support is known as its bandwidth, bandwidth is a measure of the link. Broad band optical fiber translates into promising opportunities in multimedia, since fiber is well suited to handle all types of data, voice, images, music and video at the same time.
Microwave Transmission
Another popular medium, microwave transmission, which uses the so-called line-of-sight transmission of data signals through the atmosphere. Since these signals can not bend around the curvature of the earth, relay stations, antennas are often high, for example, on the tops of mountains and buildings, are positioned at about 30 kilometers to continue broadcasting. microwave transmission has the speed, efficiency and ease of implementation. Unfortunately, in the main cities and tall buildings may interfere with microwave transmission.
Satellite Broadcast
The basic elements of satellite transmission are the ground stations that send and receive signals and the satellite component of the transponder. The transponder receives a signal from earth station, amplifies the signal, frequency and retransmits the data to ground receiving station. (The frequency is changed so that the weaker signals will not be limited by the strong outgoing signals.) This whole process takes a matter of seconds.
If the signal must travel thousands of kilometers, the satellites are usually part of the link. Messages sent around the world is likely to travel by cable or other physical link only to the nearest earth station satellite transmission. From there it is transmitted to the satellite, which sends him back to earth to another transmission station near the place of destination data. satellite communications in space, where they are suspended at 22,300 miles above the earth. Why 22,300 miles? It is there to reach geosynchronous orbit satellites in orbit, which allows them to stay put in the same spot on earth.
Mixing and matching
Network system is not limited to one type of link and, in fact, often working in different combinations, especially over long distances. Office worker who needs data from the PC's on the opposite bank is likely to pair wires used in telephone line, and then microwave and satellite transmission. Amazingly, the journey across the country and back, along with a brief stop to raise the data may take only a few seconds.

Data: How it began

Mail, Telephone, TV, radio, books, newspapers, magazines and these are the main ways we can send and receive data, and have not changed significantly in a generation. However, communication systems, computer systems, which transmit data on the lines of communication such as telephone lines and cables have been gradually developed since the mid-1960s. Let us look at how it came about.
In the early days of computing, centralized processing of data contained everything - all the processing hardware and software - in one central location. Computer manufacturers responded to this trend by building even larger, general-purpose computers, so that all departments in an organization can be serviced. In the end, however, proved to be a total centralization uncomfortable. All input data had to be physically transported to the computer and all processed material was to be received and delivered to the user.Stressing the centralized data processing was like insisting that all conversations between people are face-to-face in one designated room.
The next logical step was to teleprocessing systems-terminals connected to a central computer via communication lines.Teleprocessing systems allowed users to remotely access a central computer from their terminals in other buildings, and even other cities. However, despite the fact that access to the computer system was decentralized, all processing is still centralized, it is performed by a single company's central computer.
In 1970, companies began to use the mean, often away from the central computer. Were clearly decentralized systems because the smaller computers could do some processing on their own, but some also have access to a central computer. This new configuration has been determined distributed data processing (DDP). It is similar to teleprocessing, except that the place is not only remote access, but also remote processing. A typical use of distributed data processing system is a company or organization with multiple locations, perhaps subsidiaries or retail outlets.
The whole picture of distributed computing has changed dramatically with the emergence of networks of personal computers. The network we mean a computer system that uses communications equipment to connect two or more computers and their resources. DDP systems are networks. But especially important in today's business world are in local area networks (LAN), which are designed to share data and resources between a number of individual computer users in an office or building. We will examine the network in more detail later in this chapter.
In the next chapter we will view elements of the communications system to give an overview of how these elements work together.

Topic Computer

The following issues
Computer Networks (141 works)
Computer Networks (50 works)
Computer networks> Access Control (3 works)
Computer networks> Access Control> Congresses (1 works)
Computer networks> Access Control> United States of America (2 works)
Computer networks> Access Control (4 works)
(Show all 100)
Books under this subject
Links: How to connect everything to everything else and ... By Albert Lazlv - Barabási (1,270 versions)
Here Comes Everybody: The Power of Organizing Without ... By Clay Shirky (1,252 versions)
In Digital by Nicholas Negroponte (1066 edition)
By the way before Bill Gates (version 952)
Computer Networks by Andrew S. Tanenbaum (699 version)
Secrets and Lies: Digital Security in a networked world by Bruce Schneier (697 version)
Wealth of Networks: How Social Production convert ... By Yochai Benkler (531 version)
Growing up Digital: The Rise of Net Generation by Don Tapscott (469 version)
Hacking exposed: network security secrets and solutions ... By Stuart McClure (465 version)
Life on the Screen: Identity in the Age of the Internet by Sherry Turkle (455 version)
Unix Network Programming, Volume 1: Network socket ... By W.Richard Stevens (420th edition)
Sendmail by Bryan Costales (347 version)
Virtual Community: Homesteading on the Electronic ... By Howard Rheingold (296 version)
Time Management for System Administrators by Thomas Limoncelli (260 version)
Internet for Dummies by John R.. Levine (249 version)
SSH, Secure Shell: The Definitive Guide by Daniel J. Bart (242 version)
Takedown: the pursuit and arrest of Kevin Mitnick, ... By Tsutomu Shimomura (214 version)
CCNA: Cisco Certified Network Associate Study: Test ... By Todd Lammle (205 version)
Release 2.0 by Esther Dyson (201 version)
Computer Networks: Top-Down Approach by James F. Kurose (198 version)
System and network performance management by Thomas A.Limoncelli (189 version)
Computer Information and Communication by William Astalyngz (178 version)
Unix Network Programming, Volume 2: Interprocess ... By W.Richard Stevens (175 version)
Firewalls and Internet Security: Disposal clever hacker ... By William R.. Cheswick (173 version)
Networks for Dummies by Doug Lowe (168th edition)
SugarCRM Style: Principles of English in the Digital Age by Constance Hale (158 version)
Java Network Programming, Third Edition by Elliotte Harold quotes (154 version)
Unix Network Programming by W. Richard Stevens (153 version)
City bits: space, place, and the Infobahn by William J.. Mitchell (152 version)
Nerds 2.0.1: a brief history of the Internet by Stephen Segaller (150 version)
Network Security Hack by Andrew Lockhart (143 version)
Building Internet Firewalls: Internet and Web Security by Elizabeth D. Zwicky (143 version)
Cryptography and Network Security: Principle and Practice by William Astalyngz (140 version)
Wilderness management, and NIS (Abstract Book) by Hal Stern (136 version)
Computer Networks: Systems Approach, 3rd Edition (... by Larry L. Peterson (128 version)
Hacking: The Art of exploitation by John Ericsson (119 version)
Silence on the wire: Field Guide to Passive ... By Michal Zalewski (114 version)
Essential SNMP by Douglas Mauro (113 version)
Security by Cyrus's Peikari (110 version)
How Networks Work by Frank J. Derfler (109 version)
From counterculture to Cyberculture: Stewart Brand, ... By Fred Turner (109 version)
Computer Networks and Internets by Douglas E. Enter (101 version)
Network Intrusion Detection (3rd Edition) by Stephen Northcutt (101 version)
Apache Cookbook by Ken Coar (93 Edition)
Release 2.1 by Esther Dyson (91 Edition)
Topia by William J. Letter. Mitchell (87th Edition)
I + +: Cyborg City and its network by William Jay. Mitchell (86th Edition)
Network Security with OpenSSL by John Viega (80 Edition)
Hacking For Dummies by Kevin Beaver (78th Edition)
Data Communications, Computer Networks and Open Systems by Fred Halsall (77 Edition)
(See all books)

How home networking works

Once, home networks in the first field of technophiles - most families either did not need or can not have more than one computer. But now, in addition to using computers for e-mail, people use them for school, shopping, instant messaging, downloading music and video, and playing games. For many families, a computer is no longer enough to go around. In a family with multiple computers, home network often becomes a necessity rather than technical toys.
Home network simply approach allows your computer to communicate with one another. If you have two or more computers in your home, the network can let them share:
Files and Documents
Internet connection
Printer, print servers and scanners
Stereo, TV and game system
CD Burner
Different network types use different hardware, but they all have the same essential components:
More than one computer
Hardware (eg routers) and software (both built operating system or as a separate application) to coordinate information exchange
Way to seek information from one computer to another
More networks
How WiFi Works
Home Network Test
Curiosity Project: Internet Communications Puzzle
If you think of the computer network in your home, you several options to explore. In this article, you about different types of home computer networks, how they work and what to keep in mind if you are learning to look with email one.We create 'in the hardware to create home networks and protects the future

How does your home network

Once, home networks were primarily the technofil - most familieseither did not or could not afford more than one computer. But now,in addition to computer use for e-mail, people use them for schoolwork, shopping, instant messaging, downloading music andvideos and playing games. For many families, one computer is no longer enough for all. In households with multiple computers on a home network often becomes a necessity rather than a technicaltoy.
Home network is simply a method allows computers to communicate with each other. If you have two or more computersat home, may have a network share:
Files and documents
Internet connection
Printers, print servers and scanners
Stereo, TVs and game systems
CD burner
Different types of networks using different hardware, but all have the same basic components:
More than one computer
Hardware (eg router) and software (either built into the operating system, or as a standalone application) to coordinate theexchange of information
Journey to the information resulting from one computer to another


If you are considering links computers at home, you have severaloptions to explore. In this article you will learn about different types of home computer networks, how they work and what to keep in mind if you are considering creating one.We'll look at the hardware that creates and protects home networks in the next section.

Computer Network

The network is a collection of computers, software, and hardware that are all connected to help their users work together. Networks connect computers in a way cable systems, special software, and devices that manage data traffic. The network allows users to share files and resources, such as printers, and send electronic messages (e-mail) to each other.
computer networks are divided into two main types: / network client server and peer-to-peer network. A client / server network using one or more specific machine (server) to share files, printers, and applications. A peer-to-peer allows users to share files with other users and do not require a server, a dedicated center.
Most common network of Local Area Network or LAN for short. A LAN connects computers in a single geographic location, such as an office building, office suite, or home. In contrast, Wide Area Network (WAN) span different cities or even countries, using telephone lines or satellite links.
Networks are often categorized in other ways, too. You can refer to the network with what kind of computer circuit boards that are used to connect to each other - Ethernet and Token-Ring is the most popular choice. You can also refer to the network how the packet data for transmission cable, with terms such as TCP / IP (Transmission Control Protocol / Internet Protocol) and IPX / SPX (Internet Packet eXchnage / Sequenced Packet eXchange).
Steps to Setting-Up Networking.
All the networks through roughly the same steps in terms of design, launch, configuration, and management.
Designing Your Network
Plan the design stage to take anywhere from one to three business days, depending on how much help you have an ad on how big your network.
Here are the key tasks:
Settle on a peer-to-peer or client / server network.Select your network system software.Choose the language network.Figure out what hardware you need.Decide what security level the information you need.Selecting software and hardware solutions to handle the tasks of daily management.Rolling Out Your Network
Deploying your network requires the following steps:
Run and test network cables.Install the server or servers if you set up the client / server network.(If you set up a peer-to-peer, you usually do not have to worry about any dedicated server.)Set the workstation hardware.Plug and Cable Network Interface Cards (NICs - This network connects to the LAN).Install the hub or hub (if you use twisted-pair cable).Install the printer.Loading the server software (NOS, or Network Operating System) if your network is client / server type.Install the workstation software.Install modem hardware for remote Dail-up (if you want users to dial into the network).Install the program you want to run (software applications).Configuring Your Network
means to adjust the network configuration network for your own use.
Creating a network for your user account (name, password, and group).Creating a shared area on the disk drives for users to share data files.Creating a shared area on the disk drives for users to share programs (unless every person running the program from their own computers.)Setting up the print queue (software that lets users share a network printer).Support network installation on user workstations, so they can "talk" to your network.Managing Your Network
The work you do after your LAN up and running and configured to save a large amount of time in the coming months.
Mapping your network for easy management and troubleshooting.Setting up security measures appropriate to protect against the dangers of accidential and deliberate.Tuning up your LAN so you get the best speed out of it.Creating a corporate standard for adding hardware and software, so you do not have compatibility problems interfere with later.Putting a backup system in place so that you have copies of data and programs if your hardware fails.Install some monitoring and diagnostic software so you can check the health of your network and get early warning implending problem.Finding out how you plan to handle the problem - educating the LAN administrator, setting up a support contract with the software vendor, and so forth.Smooth Setup
One of the main advantages of a peer-to-peer is that it is easy to setup. With a simple type of peer-to-peer, you only use the built-in networking that comes with your operating system (Windows 98, Windows 95, MacOS, etc.) and you have very little software to set up - even less if you have computer that has a preinstalled operating system, like most of today's computers.
For Windows 95 and Windows 98, the basic steps to create a network of peer-to-peer is as follows:
Sketch map of your workgroup.Image of a naming convention (rules established for naming each computer).Go to the first computer on your network and click Start - Settings - Control Panel.Double-click the Network icon to display the Network dialog box.Click the Configuration tab (if not already in the foreground).Click File and Print Sharing button.Click the checkbox so it appears checked, then click OK.Click the Identification tab.Creating a workgroup member computers by typing the name of the workgroup in Workgroup: text box.Give your computer a unique name in Computer name: text box.Repeat steps 3-10 for each workstation in your new workgroup.Teach all network users how to share files, directories, and printers.Another key advantage of peer-to-peer is that you do not need to buy a computer that can not be used as a workstation client (something that the client / server network requires). Peer-to-peer networks offer another cost advantage:
This software is usually free. It either bundled with the operating system or an additional low-cost workstations.The software is simple. You do not need to spend money and time it takes someone training to learn, complex, full-featured Network Operating System.Administration & easy. Every user is administrator of small-scale network, which is responsible for any computer user on the network share.

Computer Networking

Computer Networking should be familiar as the sound is very postpretty much everyone by now adopted. It started ages ago, the original concept for communication with each other was connected to two different computers. This concept was adopted commerciallyin computer networking with the decay of computer users,institutions, schools, the IT department's most popular restraints.


Large-scale computer networking with each other's collection of many computers, printers, scanners and other devices to share information and communicate. Share files, software, etc. may not be possible without the concept of networking, the network has made life easier for many people in their professions. To order a computer without sitting on it can print out the document.
Computers are every where he is now pro machine should be in every area. If your network is more than one computer in the place it is important and as useful as having your own computer. tutorials and articles in that part of what we teach you the computer network, what types of computer networks will? What type of network, software used to require that the best approach, hardware is required, benefits, computer network security ". There are used as many as eight can be comptuer with the type of network set up, most LAN, local area networks, others are network WAN, Wide Area Network, MAN, Metropolitan area. Read more on comptuer network type
Local Area Network (LAN), home to one of the technical name of the computer networks which have developed normally, office etc is immense job networking networking device manufacturers and now it is still being Each one is there new and better solutions for network multiple computers. LAN has been implemented and was already WLAN, WLAN wireless local area networks which does the same functions as the LAN, but is replaced by wirelessly. LAN is still used to enhance the understanding it better and to solve before moving is very important. Your left side navigation to help you understand the concept involved the deployment of computer networks and that to help you make your very own local area network should be able to browse through.
Wide Area Network (WAN) Wide area network communication between each other which are located away from the computer each. Internet Van, is one classic example, and it is a collection of large numbers of other accesible information with each connecting to computers everywhere Metropolitan togather to share. Area network (MAN) to Man LAN network is not used as commonly as the van, it posses its importance when the two offices or organizations located remotly togather to make the network connected between computing systems comes. This large area but not much as Van is able to include.Very basic information on this page include computer networking.While we try our best to you all relevant articles on computer networking, with which it should be easy to form editional without help provide computer network. Left menu you go through different articles, the following steps can and should be able to make you hand sticks to the computer network.