Wireless technologies today
•Voice Cellular
•ISM Spread Spectrum broadband
•Licensed spectrum broadband
–High speed
–Cost
–Line of sight
–Slow to deploy small networks
•Fixed/Mobile/Cellular wireless narrowband
–Low speed
–Low cost
–Minimal line of sight
–Quicker to deploy large networks
Radio Frequency Ranges
Wi-Fi
•Wi-Fi is simply a trademarked phrase referring to any type of IEEE 802.11 network.
•Wi-Fi is a wireless technology that uses radio frequency (RF) to transmit data through the air.
IEEE (Institute of Electrical and Electronics Engineers) established the 802.11 Group in 1990.
The base version of the standard was released in 1997 and has had subsequent amendments. Below are some major amendments:
•802.11a - 54Mbps in the 5GHz band
•802.11b - 11Mbps in 2.4GHz band
•802.11g - 54Mbps in the 2.4 GHz bands.
• 802.11n - 100 - 270Mbps in both 2.4 GHz & 5GHz band
•802.11ac - 433Mbps or 1.3Gbps in 5GHz band
What can you do with it?
2.4GHz (802.11b/g/n)
Components/Architecture
•Access Point (AP) - Stations are connected to access points.
•Station (STA) - Mobile node.
•Basic Service Set (BSS) - Stations and the AP with in the same radio coverage form a BSS.
•Extended Service Set (ESS) - Several BSSs connected through APs form an ESS.
