Telephones And Telephone Networks example essay topic

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-multi point).

Point-to-point transmission usually involves telephone conversations or a facsimile (fax) message. Point-to-multi point 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 1's and 0's 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 different transmission media, such as copper wire, fiber optic cables, communications satellites and microwave radio. One way to categorize telecommunications media is to consider whether or not the media uses wires. Wire-based (or wire line) telecommunications provide the initial link between most telephones and telephone networks and are reliable means of transmitting messages. Telecommunications without wires, commonly referred to as wireless communications, use technologies such as cordless telephones, cellular radio telephones, walk ie-talkies, citizen band (CB) radios, pagers, and satellites.

Wireless communications offer complete mobility and flexibility. Individual people, businesses, and governments use many different types of telecommunications systems. Some systems, such as the telephone system, use a network of cables, wires, and switching stations for point-to-point communication. Other systems, such as radio and television, broadcast signals through space that can be received by anyone who has a device to receive them.

Some systems make use of several types of media to complete a transmission. For example, a telephone call may travel by means of copper wire, fiber-optic cable, and radio waves as the call is sent from sender to receiver. All telecommunications systems are constantly evolving as telecommunications technology improves. Many businesses also communicate through LANs and WANs. Without telecommunications in the world, many large businesses would not have the ability to communicate with other offices within the company in other locations quickly and efficiently. They would have to send everything through the mail, which could take days or weeks to get there.

This is what makes telecommunications so important in the business industry today. What hardware and software comprise a LAN? Hardware Components: . Servers - usually a powerful microcomputer or minicomputer with large amounts of disk space, and which can provide a variety of services to users of the network. File servers are computers dedicated to storing shared information and managing the distribution of that information throughout the local area network. Workstations - any node on a network that is accessed and used by a human being, such as a computer...

Network Interface Cards (NICs) - Also known as adapters, they provide the physical connection between the workstation and the network cable. Each adapter has a physical NIC address which is used to identify a specific node on the network, and it is assigned by the NIC manufacturer... Cables - The backbone of the LAN. They are the most expensive component.

The three most common types of cable (or media) to connect nodes are twisted pair cable, coaxial cable, and fiber optic cable... Hubs and Concentrators - Hubs are central connection points for all workstations on the LAN in a star topology. They are sometimes called multi-port repeaters, and they retransmit incoming packets to every other port on the hub. Concentrators are active hubs that allow one to add additional port cards, which means that additional workstations could then be added to the network.

Software Components: . Microsoft Windows NT - A popular network operating system known for its intuitive graphical user interface (GUI), multitasking capabilities, and compatibility with a huge array of applications... Novell Net Ware - Provides all the same features as Windows NT, and has been around much longer. Because it has been around longer, most veteran technicians are more comfortable with it. Both of these software components offer technical support on their web pages Windows NT web and Net Ware web the use and necessity of protocols, routers, switches, and network operating systems... Protocols - Ensures that the data is transferred whole, in sequence, and without error from one node to another.

Without protocols, information could be sent out of the order they need to be in, or may have several errors contained in them... 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.