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This IEEE wireless specification runs in the 5GHz spectrum, and if you use the 802.11h extensions, you have 23 non-overlapping channels. It can run up to 54Mbps, but only if you are less than 50 feet from an access point.
This IEEE Wireless spec runs in the 2.4GHz range and has 3 non-overlapping channels and can handle long distances, but with a max data rate of 11Mpbs.
This IEEE Wireless spec runs in the same 2.4GHz range, but has a higher data rate of 54Mpbs if you are less than 100 feet from an access point.
What type of Ethternet collision detection was created to solve the problems in the RF spectrum?
CSMA/CA or Carrier Sense Multiple Access with Collision Avoidance
What is CSMA/CA also called?
- RTS/CTS or Request To Send, Clear To Send, because of the way that hosts must communicate to the access point
What modulation technique does 802.11b use?
DSSS or Direct Sequence Spread Spectrum
What data rates does 802.11g operate at?
How many channels are configurable in the 2.4GHz range?
11 channels configurable
How many channels are non-overlapping and which are they?
- 3 non-overlapping channels
- 1, 6, & 11
What is the maximum data rate for 802.11a?
How many non-overlapping channels does 802.11a have?
12 non-overlapping channels
How wide is each channel in the 2.4GHz range?
What data rates does 802.11a operate at?
What are 2 new features of the 5GHZ radio that are part of the 802.11h specification?
- Transmit Power Control (TPC)
- Dynamic Frequency Selection (DFS)
What does Dynamic Frequency Selection (DFS) do?
continuously monitors a device's operating range for any radar signals that are allowed to operate in portions of the 5GHz band
What does DFS do to prevent interference from occurring on the WLAN if it discovers any radar signals?
abandon the occupied channel or mark it as unavailable
At what distance do you need to be to get the full 54Mbps benefit from 802.11a & 802.11g?
between 50 feet and 100 feet (at the farthest) and less if there are any obstructions between the client and the access point
Transmit Power Control (TPC) is responsible for what wireless element?
This is used to control transmission power to cover various size ranges. Also this enables the client and access point to communicate. This means the client machine can fine-tune it's transmit power dynamically so it uses just enough energy to preserve it's connection to the access point, conserve it's battery power, plus reduce interference on the neighboring WLAN cells.
What features does 802.11n add to build on the 802.11 standards?
How does Multiple-Input Multiple-Output (MIMO) work?
- employs multiple transmitters and receiver antennas to increase data throughput
- uses up to 8 antennas, most use 4
What are some of the MAC-layer functions provided in the WLAN controller?
- 802.11 -
- association and reassociation (mobility)
- frame translation and bridging
What allows the splitting of 802.11 protocol packets between the Cisco LWAPP-based AP?
Which IEEE committee has been sanctioned by WPA and is called WPA 2?
802.11i standard has been sanctioned by WPA and is termed WPA version 2.