Network and Telecommunications: The evolution in telecommunication: From wire to wireless.

Twisted-pair wire: ordinary telephone wire, consisting of copper wire twisted into pairs and is the most widely used medium for telecommunications. These lines are used to communications networks throughout the world for both voice and data. Moreover, it is cheap and easy to install.

Coaxial cable: consisting of sturdy copper or aluminium wire wrapped with spacers to insulate and protect it. It’s commonly used in television cable. Furthermore, coaxial cable cheaper than fibre-optic cable but expensive than twisted-pair wire. Coaxial cable is also used in office buildings and other worksites for LAN.

Fiber-optic cable: consisting of one or more hair-thin filaments of glass fiber wrapped in a protective jacket. They can conduct pulses of visible light elements generated by laser at transmission rates. Fiber-optic cable has faster transmission
speeds and its freedom electrical interference. Moreover, it is less susceptible to interference (noise) and therefore more secure. It also a small size in thinner and lighter.

Wireless LANS: uses wireless radio-wave technology to connect PCs within an office or a building. And it can be high-frequency, similar to digital cellular, or low frequency (spread spectrum) such as Wi-Fi

WiMAX: newest of the network types. Similar to Wi-Fi, but operates over longer distances and at higher speeds. It can use both licensed and non-licensed frequencies.

Bluetooth: short-range wireless technology and connects PCs to devices, such as a printer .It also fairly low cost to implement.

Terrestrial Microwave: earthbound microwave systems transmit high-speed radio signals. It also has follows a line-of-sight path between relay systems spaced about 30 miles apart. Microwave antennas are placed on top of buildings and must transmit in straight line with no obstructions.

Communications Satellites: space station that receives microwave signals from earth-based station, amplifies signals, and broadcasts signals back to any number of earth-based stations. E.g. GPS

Cellular and PCS system: Geographic areas are divided into cells. Moreover, each cell has a low-power transmitter or radio relay antenna. Computers and other communications processors coordinate and control the transmissions to and from mobile users

Wireless Web: Wireless internet access is growing as Web-enabled information appliances proliferate such as smart telephones, pagers, PDAs and all are very thin clients in wireless networks.