6. Wireless communication

This form of communication makes use of radio waves in order to transmit and receive information.wireless router

With digital data transfer in mind, a number of standards have been developed. Each one specifying the protocols to be used and the maximum bandwidth it can support. These are called the IEEE 802.11 standards.

Standard Outdoor range Indoor Range Max Bandwidth
802.11b 140 m 38 m 11 Mbps
802.11g 140 m 38 m 54 Mbps
802.11n 250m 70m 150 Mbps

The latest standard as shown above is 802.11n offfering nearly twice the range of earlier standards and nearly three times the bandwidth. When you buy wireless network equipment such as a wireless router make a note of the standard it supports.

In addition to the wireless standards, a group of international companies have banded together to create an alliance. It is called the Wi-Fi Alliance and it owns the trademark term 'Wi-Fi'. Its main purpose is to ensure that all equipment using the term 'Wi-Fi Certified' are compatible with one another.

Wi-Fi is widely used for LANs and WANs as it does not need any cabling to be laid down. It does need a device called a Wireless Access Point or WAP to be present on the network to handle the radio traffic. WAPs are commonly called 'hotspots' and can be found in airports, stations, cafes, library and other public spaces.

Most laptops are WiFi enabled along with other devices such as PDAs, netbooks, smartphones, e-book readers, game consoles and music players.

Uses

  • Connecting to an organisation's Local Area Network
  • Connecting to the Internet through a hotspot
  • Smartphones and PDA connecting to the internet
  • Wirelessly downloading electronic books into a reader
  • Wirelessly streaming music throughout a home
  • Wi-Fi enabled printers
  • Games consoles to connect to the Internet

 

Advantages
Disadvantages
No need for physical cables Slower than cabled networks e.g. 54 Mbps compared to the 1000 Gbps that Gigabit Ethernet offers
The laptop or device can work anywhere within range of a WAP Requires a Wireless Access Point (WAP) to be present
Can work through walls and on different floors as long as the radio signal is not too weak Requires encryption to ensure data privacy
Smartphones can roam the Internet through the home network without incurring expensive 3G charges It can only support a limited number of simultaneous connections so not so good as a company-wide LAN
Sufficient bandwidth for most Internet use although streaming video is more of a challenge_blue Performance depends on the structure of the building and any obstacles there may be weakening the radio signal
Wi-Fi certified devices are guaranteed to be compatible  

 

 

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Click on this link: WAP and Wi-Fi