WiFi Standards

Question 1

802.11a

Answer 1

• 5 GHz only
• 54 Mbps
• 23 channels 20 MHz wide
• Channels don’t overlap
• 1999
• WiFi 1

Question 2

802.11b

Answer 2

• 2.4 GHz
• 11 Mbps
• 14 channels 20 MHz wide
• Channels overlap
• 1999
• WiFi 2

Question 3

802.11g

Answer 3

• 2.4 GHz
• 54 Mbps
• Same encoding as 802.11b
• 2003
• WiFi 3

Question 4

802.11n

Answer 4

• 2.4 GHz and 5 GHz
• 72 Mbps per stream / 150 mbps for a bonded channel
• Two adjacent 20 MHz channels can be combined into one 40 MHz channel (channel bonding)
• Channel bonding is only practical on the 5 GHz band
• MIMO (Multiple Input Multiple Output) - multiplexing signal streams from 2-3 separate antennas.
• 2009
• WiFi 4

Question 5

802.11ac

Answer 5

• 5 GHz only
• Can use 2.4 GHz antenna for backwards compatibility
• Allows up to 8 streams
• Multiuser MIMO (up to 4 clients simultaneously)
• 433 Mbps per stream over an 80 MHz channel
• Up to 3.46 Gbps
• 2013
• WiFi 5

Question 6

802.11ax

Answer 6

• 2.4 GHz and 5 GHz
• WiFi 6e adds 6 GHz
• Up to 8 clients simultaneously
• Orthogonal Frequency Division Multiple Access (OFDMA) works alongside MU-MIMO to improve data rates when multiple clients are connected
• Up to 9.6 Gbps
• 2019
• WiFi 6