Network Examples of Component Alternatives 72 page.pptx
- 1. Network Examples of Component Alternatives
- 2. Media: Twisted-pair wire, coaxial cable, fiber optics, microwave, radio communications satellites, etc. Processor: Modems, multiplexers, bridges, routers, hubs, gateways. Software: Telecommunications access programs, network operating systems, end user communications packages Channels: Analog/digital, switched/non switched, transmission speed, circuit/message/packet switching, simplex/duplex, asynchronous/synchronous Topology/Architecture Star/ring/bus/ OSI
- 3. What is Telecommunications Media/Channel. Discuss its different types Telecommunications Media/Channels (also called communications lines or links) is the path that connects sender and recover to transfer data between sending and receiving devices in a telecommunications network. There are different types of telecommunication media/channel, which are the following.
- 4. Twisted Pair Wiring Twisted pair wire consists of two strands of insulated copper wire, twisted around each other in pair. They are then covered by another layer of plastic insulation. Twisted pair cabling is the same type of cabling system used for home and office telephone system and local area networking. Advantage: it is inexpensive and easy to install. Disadvantage: it create noise and its transmission is easily interrupted by magnetic.
- 6. Coaxial Cable Coaxial cable consists of insulated copper or aluminum wire covered by insulating material. The insulated copper wire covered by copper mesh. It is widely used for cable television and local area network. They allow high speed data transmission and are used instead of twisted pairs wire lines.
- 8. Fiber optic Cable A fiber optic cable consists of hundreds or thousands of thin strands of glass. It is thinner than a human hair. Data transfer rate of fiber optics is very fast. There is no chance of data loss. Light pulse is not affected by random electromagnetic interference in the environment, they have much lower error rate than normal telephone twisted pair or coaxial cable. It is latest technology according to a research.
- 9. Fiber Optic
- 10. Microwave Microwave are radio waves that are used to provide high speed transmission. Microwave system transmit high speed radio signals in a line of sight path between relay stations placed approximately 30 miles apart each other. Microwave antennas are usually placed on top of building, tower, hills etc.
- 11. Communications satellites Communication satellite is a space station. It receive microwave signal from earth station and retransmits them back to the earth. The data transfer speed of communication satellite is very high. The transmission from earth station to satellite is called uplink. The transmission from satellite to earth station is called downlink.
- 12. Cellular radio Cellular radio is a broadcast radio used for mobile communications. It is specially used in wireless modems and cellular telephones. Cellular telephone is a telephone device that uses high frequency radio waves to transmit voice and digital data.
- 13. Broadcast radio Broadcast radio is a wireless transmission medium. It distributes radio signals through the air over long and short distance. Radio transmission requires a transmitter to send broadcast radio signals and receiver to receive the signal. Bluetooth an example of short range broadcast radio communication.
- 14. Telecommunications carriers The company or organization that provides network/communication facility is called telecommunication carriers. Telecommunications channels for wide area networks can be owned by an organization or provided by other companies. For example: Internet which is wide area network run by some Organization. There are two types of carriers.
- 15. 1) Common carriers An organization that supplies communications services to other organization and to the public as authorized by government agencies. Example, are the former Bell operating companies, General Telephone and electronics, and many independent telephone companies. In Pakistan PTCL is common carrier telecommunication system.
- 16. 2)Value Added Carriers Third party vendor (دار )دکان who leas telecommunication lines from common carriers and offer a variety of telecommunication services to customer. Messages from customers are transmitted in groupings called packets. In Pakistan the value added companies are world call, Nokia, Mobilink, U-fone, Paktel etc.
- 17. Modems Modem stands for modulation and demodulation. Modem is an electronic device that converts digital signals to analog and analog signal to digital. Modem is the most common type of communications processor.
- 18. Multiplexer Multiplexer means transmitting a large number of information unites over a smaller number of channels or lines. Multiplexer is an electronic device that allow a single communication channel to carry simultaneous data transmissions from many terminals. Thus, a single communications line can be shared by several terminals.
- 19. Inter-net-work processors These are the communication processor used by local area network to interconnect them with other local area and wide area networks example of network processor are bridges, routers, hubs, or gateways.