Wireless LAN Standards

802.11b

• Almost same time as "a"
• Released in 1999
• Frequency 2.4Ghz
• Max Speed 11Mbps
  • (realistically 6-7 Mbps)

802.11a

• Released in 1999
• Frequency 5 Ghz
  • A lower frequency tends to go a bit further
  • Higher frequencies (smaller antennas)
  • 2.4 goes very far, 5Ghz doesn't go as far.
• Max Speed 54 Mbps
  • Actual chips needed to be built to this specific frequency (a was not compatible with b)

802.11g

• Released 2003
• Frequency 2.4 Ghz
• Speed 54 Mbps
  • Same speed in A, but we have a radio chip set that is backwards compatible, can support b, a, and g.

802.11h

• Released 2003
• Frequency 5 Ghz
• Key features:
  • Dynamic Frequency Selection (DFS)
    • DFS helps avoid interference with radar systems by detecting their presence and switching channels
  • Transmit Power Control (TPC)
    • TPC manages the transmission power of wireless devices to minimize radio frequency interference

802.11n

• Released 2009
• Frequency 2.4 & 5 Ghz
• Multi-input Multi-output (MIMO)
  • Up to 4 streams
  • Each stream has 54 Mbps.
• Max Speed 600 Mbps

802.11ac

• Released 2013
• Frequency 5 Ghz (2.4 missing)
• Multiple Multi-input Multi-output (MU-MIMO)
  • Up to 8 streams
• Max Speed 3.5 Gbps
• More susceptible to attenuation (signal loss)
  • Not go as far.

802.11ax

• Released 2021
• Frequency 2.4 Ghz, 5 Ghz, 6 Ghz
  • Wifi 6 (2.4 & 5 Ghz)
  • Wifi 6E (6 Ghz)
• Multiple Multi-input Multi-output (MU-MIMO)
  • Up to 8 streams
• Max Speed ~10 Gbps
• High Density performance 4X over 802.11ac

802.11be = wifi 7

• 6Ghz, 5Ghz, and 2.4Ghz

Single duplex - one person talks at a time

• this was before