A communication satellite is an artificial satellite sent to space for the purpose of telecommunications. Modern communications satellites use a variety of orbits including: geostationary, molniya orbits, elliptical orbits, and low (polar and non-polar earth orbits.
For fixed (point to point) services, communication satellites provide a microwave radio relay technology complementary to that of communication cables. They are also used for mobile applications such as communications ships, vehicles, planes and hand – held terminals and for TV and radio broadcasting. NETWORKS A computer network, or simply a network is a collection of computers and other hardware components interconnected by communication channels that allow sharing of resources and information . here at least one process in one device is able to send/receive data to/from at least one process residing in a remote device, then the two devices are said to be in a network. Simply, more than one computer interconnected through a communication medium for information interchange is called a computer network.
Networks may be classified according to a wide variety of characteristics, such as the medium used to transport the data, communications protocol used, scale, topology and organizational scope. EXTRANETS An extranet is a computer network that allows controlled access from the outside, for specific business or educational purposes.
In a business-to-business context, an extranet can be viewed as an extension of an organization’s intranet that is extended to users outside the organization, usually partners, vendors, and suppliers, in isolation from all other Internet users. In contrast, business-to-consumer (B2C) models involve known servers of one or more companies, communicating with previously unknown consumer users. An extranet is similar to a DMZ in that it provides access to needed services for channel partners, without granting access to an organization’s entire network.
Three Most Powerful Men in Computer Business The computer industry now has become one of the biggest since the 1950s, where everybody could not afford a computer, and believed that it was only for the rich and famous. Today, if you don’t own a computer you would be considered as old fashioned or unfortunate. Computers have dominated the world, having one is essential. Particular students would ...