CompTIA A+ 1101 Wireless Network Standards & Channels

Question 1

• one of the original 802.11 wireless standards
• operates in the 5 Ghz range, or other frequencies with special licensing
• 54 megabits per second speeds
• smaller range than 802.11b, which operates in the 2.4 Ghz range (due to the higher, 5 Ghz frequency being absorbed by objects in the way)
• not commonly seen today

Answer 1

802.11a

Question 2

• also one of the original 802.11 wireless standards
• operates in the 2.4 Ghz range
• 11 megabits per second speeds (much slower than 802.11a)
• better range than 802.11a, due to less absorption problems
• more frequency conflict (less channels)
• not commonly seen today

Answer 2

802.11b

Question 3

• an upgrade to 802.11b
• operates in the 2.4 Ghz range
• 54 megabits per second speeds (similar to 802.11a)
• backwards compatible with 802.11b (802.11b devices are compatible with an 802.11g network)
• 2.4 Ghz frequency conflict issues

Answer 3

802.11g

Question 4

• upgrade from 802.11a, 802.11b, and 802.11g
• operates at both 5 Ghz and 2.4 Ghz
• 40 megahertz channel width
• maximum theoretical speeds of 600 megabits per second, when using 40 Mhz mode and 4 antennas
• introduced MIMO (multiple-input multiple-output), which allows devices to transfer much more information simultaneously, between the end station and the access point

Answer 4

802.11n (WiFi 4)

Question 5

• significant improvements over 802.11n
• operates in the 5 Ghz range
• up to 160 Mhz channel bandwidth
• introduced denser signaling modulation (faster data transfers)
• 8 MU-MIMO (Multi User MIMO) downlink streams, for nearly 7 gigabits per second maximum total speeds

Answer 5

802.11ac (WiFi 5)

Question 6

• the successor to 802.11ac
• operates at 5 Ghz and 2.4 Ghz
• 20, 40, 80, and 160 Mhz channel widths (total possible throughput of about 1201 megabits per second, per channel)
• 8 bi-directional MU-MIMO streams, for nearly 10 gigabits per second maximum total speeds
• introduced orthogonal frequency-division multiple access (OFDMA) (works similarly to cellular communication, and improves high-density installations)

Answer 6

802.11ax (WiFi 6)