Wi-fi Technology

Wi-Fi Technology

  Written By

Tamoor Akbar

(National Textile University,Pakistan)

October2008

What is WiFi ?

Wi-Fi is new technology enabling images from a computer to be transmitted to the projector without a hard-wire connection. Hence the use of a VGA cable to connect the computer and the projector is no longer required.

Why Wi-Fi?

The purpose of Wi-Fi is to hide complexity by enabling wireless access to applications and data, media and streams. The main aims of Wi-Fi are the following:

• make access to information easier
• ensure compatibility and co-existence of devices
• eliminate cabling and wiring
• eliminate switches, adapters, plugs, pins and connectors.

How wi-Fi works?

It uses a new technology, which for the purpose of transmission of information over greater distances. Put simply, WiFi can transmit information up to ten times faster than Bluetooth, and up to six times further than Bluetooth.WiFi networks use radio technologies called IEEE 802.11b or 802.11a to transmit data from the internet connection to the host computer (e.g. your laptop). These technologies provide reliable and fast wireless connectivity and to some degree a level of security (to be addressed below). A Wi-Fi network can be used to connect computers to each other, to the Internet, and to wired networks.

Wi-Fi networks operate in the unlicensed 2.4 and 5 GHz radio bands, with an 11 Mbps (802.11b) or 54 Mbps (802.11a) data rate or with products that contain both bands (dual band), so they can provide real-world performance similar to the basic 10BaseT wired Ethernet networks used in many offices

Elements of a WI-FI Network

•         Access Point (AP) - The AP is a wireless LAN transceiver or "base station" that can connect one or many wireless devices simultaneously to the Internet.

•         Wi-Fi cards - They accept the wireless signal and relay information.They can be internal and external.(e.g PCMCIA Card for Laptop and PCI Card for Desktop PC)

•         Safeguards - Firewalls and anti-virus software protect networks from uninvited users and keep information secure.

 Limitations

 •         Interference

•         Degradation in performance

•         High power consumption

•         Limited range

  Uses

·        Wi-Fi enabled device such as a PC, game console, mobile phone, MP3 player or PDA can connect to the Internet when within range of a wireless network connected to the Internet. The coverage of one or more interconnected access points — called a hotspot — can comprise an area as small as a single room with wireless-opaque walls or as large as many square miles covered by overlapping access points. Wi-Fi technology has served to set up mesh networks,

·        In addition to restricted use in homes and offices, Wi-Fi can make access publicly available at Wi-Fi hotspots provided either free of charge or to subscribers to various providers. Organizations and businesses such as airports, hotels and restaurants often provide free hotspots to attract or assist clients. Enthusiasts or authorities who wish to provide services or even to promote business in a given area sometimes provide free Wi-Fi access. Metropolitan-wide Wi-Fi (Muni-Fi) already has more than 300 projects in process.[2] There were 879 Wi-Fi based Wireless Internet service providers in the Czech Republic as of May 2008.

·        Wi-Fi also allows connectivity in peer-to-peer (wireless ad-hoc network) mode, which enables devices to connect directly with each other. This connectivity mode can prove useful in consumer electronics and gaming applications.

·        Many consumer devices use Wi-Fi. Amongst others, personal computers can network to each other and connect to the Internet, mobile computers can connect to the Internet from any Wi-Fi hotspot, and digital cameras can transfer images wirelessly.

·        One can also connect Wi-Fi devices in ad-hoc mode for client-to-client connections without a router.

• In wake of recent mining tragedies, some technology companies have suggested extension of wireless real-time location technology using WiFi networks to pinpoint miners trapped underground – a solution that could save lives in the future.

 Wi-Fi technology has spread widely within business and industrial sites. In business environments, just like other environments, increasing the number of Wi-Fi access-points provides redundancy, support for fast roaming and increased overall network-capacity by using more channels or by defining smaller cells. Wi-Fi enables wireless voice-applications (VoWLAN or WVOIP). Over the years, Wi-Fi implementations have moved toward "thin" access-points, with more of the network intelligence housed in a centralized network appliance, relegating individual access-points to the role of mere "dumb" radios. Outdoor applications may utilize true mesh topologies. As of 2007 Wi-Fi installations can provide a secure computer networking gateway, firewall, DHCP server, intrusion detection system, and other functions.

Growth of Wi-Fi technology in some previous years clearly shows Wi-Fi will cannibalize all other wireless technologies.We can say "the future is of Wi-Fi".