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
- Dynamic Frequency Selection (DFS)
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