Network and Telecommunications

The evolution in telecommunication: From wire to wireless.

Telecommunication is a highly technical, rapidly changing field of information system technology. However, it is necessary that you understand some of the important characterictics of the basic components of telecommunications networks.

-Terminals:any output/input device that uses telecommunications networks to transmit or receive data.

-Telecommunication processors:data transmission and reception between terminals and computers.

-Telecommunications channels:which data transmitted and received that use combination of media.

-Computers:of all types are interconnected by telecommunication networks.

-Telecommunications control software:consists of programs that control telecommunications activities and manage the functions of telecommunications networks.

Wired Technologies

Twisted-Pair Wire-ordinary telephone wire,consisting of copper wire twised into pairs.

-used extensively in home and office telephone systems and many

local area networks and wide area networks.

-transmission speeds can range from 2 million bits per second to

100 millions bits per second.

Coaxial cable-consists of a sturdy copper or aluminum wire wrapped with spacers to

insulate and protect it.

-groups of coaxial cable may be bundled together in a big cable for ease

of installations.

-allow high-speed data transmission from 200 million to over 500 million

bits per-second.

-used in many office building and other worksides for local networks.

Fiber optics-consists of one or more hair-thin filaments of glass fiber wrapped in a

protective jackets.

-speeds is hundreds times faster than coaxial cable and thousands of times

better than twisted-pair wire lines.

-less need for repeaters for signal retransmissions than copper wire media.

Wireless technologies

Terrestrial microwave-invovles earthbound microwave systems that transmit high

speed radio signals in a line-of-sight path between relay

stations spaced approximately 30 miles apart.

-placed on top of building,towersand mountain peaks.

Communications satellites-used microwave radio as their telecommunications

medium.

-satellites are powered by solar penals and can transmit

microwave signals a rate of several hundred million bits per

second.

Cellular and PCS systems-used several radio communications technologies.Divide a

geographic areas or cells.

-each cell has its low-power transmitter to relay calls from

one cell to another .

Wireless LANs-a high-frequency radio technology similar to digital cellular called

spread spectrum.

-eg.WiFi is faster and less expensive,enable laptop PCs,PDAs,and other

devices with WiFi modems to connect easily to the internet.

Bluetooth-short range wireless technology.is rapidly being built into computers and

other devices.

-operates about 1Mbps and has an effective range from 10 to 100 meters.