Many devices can use wi-fi e.g. personal computers, video-game consoles, smartphones, some digital cameras, tablet computers and digital audio players. These can connect to a network resource such as the Internet via a wireless network access point. Such an access point (or hotspot) has a range of about 20 meters (65 feet) indoors and a greater range outdoors. Hotspot coverage can comprise an area as small as a single room with walls that block radio waves, or as large as many square miles achieved by using multiple overlapping access points.
WIFI Introduction (PART I)
Wireless way to handle networking.
The big advantage of WiFi is its simplicity.
You can connect computers anywhere in your
home or office without the need for wires. The
computers connect to the network using radio
signals, and computers can be up to 100 feet or
• A Wi-Fi hotspot is created by installing an access point to an internet
• An access point acts as a base station.
• When Wi-Fi enabled device encounters a hotspot the device can then
connect to that network wirelessly.
• A single access point can support up to 30 users and can function within
a range of 100 – 150 feet indoors and up to 300 feet outdoors.
• Many access points can be connected to each other via Ethernet cables
to create a single large network.
Also known as IEEE 802.11, is a set of standards to allow different
devices to communicate wirelessly. It is created by the IEEE
(pronounced eye-triple-e) LAN/MAN Standards Committee.
Appear in late 1999
• Operates at 2.4GHz radio spectrum
• 11 Mbps (theoretical speed) - within 30 m Range
• 4-6 Mbps (actual speed)
• 100 -150 feet range
• Most popular, Least Expensive
• Interference from mobile phones and Bluetooth devices which
can reduce the transmission speed.
• Introduced in 2001
• Operates at 5 GHz (less popular)
• 54 Mbps (theoretical speed)
• 15-20 Mbps (Actual speed)
• 50-75 feet range
• More expensive
• Not compatible with 802.11b
• Introduced in 2003
• Combine the feature of both standards (a,b)
• 100-150 feet range
• 54 Mbps Speed
• 2.4 GHz radio frequencies
• Compatible with ‘b’
• Use OFDM Technology
• Introduced in 2009
•multiple antennas that function in a
"MIMO" mode ( multiple-input multipleoutput)
• 2.5 GHz and 5 GHz radio frequency
•150 Mbps speed
•Range up to 230 feet indoor
• Small Businesses or SOHO
• Large Corporations & Campuses
• Health Care
• Wireless ISP (WISP)
Ease of Installation
Use unlicensed part of the radio spectrum
• The 802.11b and 802.11g flavors crowded with other
•Power consumption is high.
• It is not always configured properly by users.
• Limited range
As Wi-Fi is now shipped in millions of products and
deployed in millions of homes, business and hotspots
worldwide, the technology has moved beyond the realm
of a computer feature. Wi-Fi has fast become a cultural
802.11ac: The Fifth Generation of Wi-Fi Technical White Paper
Impact of wireless technology