Week 5: Connecting a Network (Wire and Wireless)

WIRE AND WIRELESS
What is wireless
  • Wireless signal (radio) signals are used to send data through the airwaves between devices, instead of physical cable.
  • Wireless technology is generally used for mobile IT equipment. It encompasses cellular telephones, tabs, personal digital assistants (PDA's), wireless networking.
  • Eg. GPS units, garage door openers, satellite television and etc.


Wired VS Wireless


Uses
  • Mobile users can use their cellular phone to access e-mail anywhere and anytime.
  • Travellers with potable computers can connect to the internet through base stations installed in airports, railway station, and other public locations.
  • At home, users can connect devices on their desktop to synchronize data and transfer files.


Types of Wireless




Wireless Technology 
  • Infra Red (Do not use signals in radio frequency)
    • Send data as infrared light rays in short distance.
    • Limitation: Requires line-of-sight transmission.
    • Not popular now: still used in remote control.





  • Bluetooth
    • Is an industrial specification for wireless personal area network (PANs).
    • Designed for very short range <10M
    • Connect and exchange information between devices such as mobile phones, laptops, PCs, printers, digital cameras and video games.
    • Data speed up to 3Mbps.

  • Wireless Local Area Networks (WLANs)
    • WLANs are based on the IEE 802.11 standard.
    • IEE 802.11 standard is a standard that has been developed by IEE (Institute of Electrical and Electronic Engineers) to differentiate between the various technology families.
    • There are three physical layers for WLANs: two radio frequency specifications (RF- direct sequence and frequency hopping spread spectrum) and one infrared (IR).



  • WiMax
    • To extend the range of wireless network. 
    • Speed up to 70 Mbps, range 3 miles.
    • Provides access to internet access to fixed location with larger coverage.


  • Broadband
    • In general, broadband refers to telecommunication in which a wide band of frequencies is available to transmit information. 
    • Because a wide band of frequencies is available, information can be multiplexed and sent on many different frequencies or channels within the band concurrently, allowing more information to be transmitted in a given amount of time (much as more lanes on a highway allow more cars to travel on it at the same time). 





Mobile Phone: 1G, 2G, 3G, and 4G






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