Telecommunications

What is Telecommunications?

Telecommunications enables people around the world to contact one another, to access information instantly, and to communicate from remote areas. It usually involves a sender and one or more recipients linked by a technology, such as a telephone system, or computer network (LANs or WANs), that transmits information from one place to another. Devices used for telecommunications can convert different types of information, such as sound and video, into electronic signals. These signals then can be transmitted to different types of media such as telephone wires, or radio waves. Once the signal reaches its destination it then gets converted back into an understandable message, such as the sound on a telephone, video on a television screen, or pictures on a computer monitor, Telecommunications also allows to send and receive personal messages across town, between countries, and to and from outer space. It also provides the key medium for news, data, information and entertainment.

Telecommunication messages can be sent in a variety of ways, and by a wide range of devices (radios, televisions, telephones, computers, etc.). They can be sent from one sender to a single receiver (point-to-point) or to many receivers (point-to-multipoint). Point-to-point transmission usually involves telephone conversations or a facsimile (fax) message. Point-to-multipoint transmissions (also called broadcasts), provide the basis for commercial radio and television programming.

Most personal computers communicate with each other and with larger networks, such as the internet, by using the ordinary telephone line. Since the telephone network functions by converting sound into electronic signals, the computer must first convert its digital data into sound. They do this with a device called a modem, which is short for modulator/demodulator. A modem converts a stream of 1s and 0s from a computer into an analog signal that can be transported over a telephone network. The modem of the receiving computer demodulates the analog signal back into a digital form that the computer can understand. The internet can also be accessed by higher speed sources, such as cable, DSL and ISDN.

Telecommunications systems deliver messages using a number of dif...

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· Routers – Connect network segments and intelligently direct data. They are used to connect LANs to WANs. It operates at the network layer of the OSI model. The strength of a router lies in its intelligence, they can determine the shortest fastest path between nodes. The internet relies on millions of routers around the world.

· Switches – Subdivide a network into smaller logical pieces. Operates from the Data Link layer of the OSI model. By having multiple ports, they can make better use of limited bandwidth and prove more cost efficient then bridges. Each port on the switch acts like a bridge, and each device connected to a switch effectively receives its own dedicated channel. In other words, a switch can turn a shared channel into several channels.

· Network Operating Systems – A special system software designed to manage data and other resources on a server for a number of clients. Network operating systems also provide the ability to manage network security, network users and groups, protocols, and networked applications.