Wireless Flashcards
802.11b max speed
Up to 11 Mb/sec
802.11a max speed
Up to 54 Mb/sec
802.11a frequency
5 Ghz only
802.11b frequency
2.4 Ghz
802.11b data transfer standard
DSSS (direct sequence spread spectrum)
802.11a data transfer standard
OFDM (orthogonal frequency divisional multiplexing). Allowed it to get to 54 Gb/sec
Other devices that operate at 2.4 Ghz
Baby monitors
Cordless phones
Convection/microwave ovens
WiMAX frequency?
2.4 Ghz
Lower frequency gives you more range, or less?
Typically more
802.11a range
60-70 feet max
802.11g max speed
Up to 54 Mb/sec
802.11g frequency
2.4 Ghz
802.11b range
Average 300 feet
802.11g range
Average 300 feet
802.11g data transfer standard
ODFM and DSSS
Channels and spectrum range for 2.4 Ghz, 802.11b
16 channels, only 1-11 used in the US
Channel 1 starts at 2.412 Ghz, channel 2 starts at 2.417, channel 3 starts at 2.422, etc.
Channel 11 ends at 2.462 Ghz.
Each channel 22 MHz wide
802.11b channels used to avoid channel congestion
1, 6, and 11 (since they don’t overlap). Allows multiple access points nearby without interference.
Channels and spectrum ranges for 5 Ghz, 802.11a
165 channels
5.180 - 5.809 Ghz
802.11n max speed
Up to 600 Mbps (theoretical). 150 Mbps per antenna, max of four antennas.
802.11n frequency
2.4 Ghz and 5 Ghz. Dual band technology.
802.11n data transfer standard
MIMO (multiple in multiple out) / OFDM only.
802.11n channel bandwidth
Starts at 20 MHz, can grow to 40 MHz as needed
MIMO
Multiple in multiple out
Channel bonding
Taking two different wireless channels and bonding them together to double speed (e.g., the Atheros Super-G wireless card). Today supported natively in 802.11n.
