2.3 (802.11) Flashcards
What is 802.11a?
The first wireless standard was introduced in 1999.
5 GHz.
Up to 54Mbit/s.
Smaller range than 802.11b.
Quite rare today.
What is 802.11b?
Introduced 1999 like 802.11a.
Difference is that b is slower than a and in a different frequency of: 2.4GHz.
11 Mbit/s.
As such it has BETTER RANGE, and goes through objects easily.
What is 2.4GHz good for?
Longer range.
Goes through large objects better.
However more frequency conflicts. with microwaves etc.
What is 5GHz good for?
5 GHz is your best choice to take advantage of higher speeds.
Shorter range.
What is 802.11g?
Upgrade from 802.11b.
2003.
Works in 2.4GHz.
Similar speed to 802.11a = up to 54Mbit/s,
Backwards compatible with b.
What is 802.11n (Wi-Fi 4)?
Update from g and others.
October 2009.
Works at 5 and 2.4 GHz.
40 MHz channel widths.
Up to 600 Mbit/s.
What is Wi-Fi 4?
The new/simplified name for 802.11n.
What is MIMO?
Multiple-Input Multiple-Output (MIMO) is a wireless technology that uses multiple transmitters and receivers to transfer more data at the same time.
What is 802.11ac (Wi-Fi 5)?
Jan 2014.
Huge improvements over 802.11n.
Only in 5 GHz.
Up to 160 MHz channel bandwidth.
Increased channel bonding.
Denser signalling modulation.
8 MU-MIMO downlink streams.
Nearly 1 gigabit per second.
What is 802.11ax (Wi-Fi 6)?
Feb 2021.
Uses 5GHz and/or 2.4GHz.
20, 40, 80 and 160 MHz channel widths.
1201 megabits per second per channel.
Uses the new OFDMA.
What is OFDMA?
The main benefit of OFDMA is that it allows an AP to allocate the whole channel to a single user at a time or it may partition a channel to serve multiple users simultaneously. OFDMA is ideal for low bandwidth applications and results in better frequency reuse, reduced latency, and increased efficiency.
It is basically faster for condensed and high population of people areas.
