IEEE STANDARDS
This IEEE Wi-Fi standard (also known as Wi-Fi 0) was the first to be introduced. It was 1-2 Mbps fast and used the redundant DSSS transmission technology.
IEEE 802.11-1997
These three non-overlapping 2.4 GHz Wi-Fi channels can be used on nearby access points without interfering with one another.
Channels 1, 6, and 11.
2.4GHz Wi-Fi is split up between three channels (1, 6, and 11). 5GHz Wi-Fi channels are more plentiful (up to 25) and are classified as one of five "UNII bands." What are they called?
UNII-1, UNII-2, UNII-2 Extended, UNII-3 and the ISM band.
Name the Wi-Fi technique introduced with IEEE standard 802.11n in 2009 where multiple smaller frequency channels can be combined into one wider channel to increase data speed. With this feature, you can have channels widths of 40MHz, 80 MHz, 160MHz and, as of late, 320MHz with the 5GHz frequency band.
Channel bonding
Define modulation and how it is used for Wi-Fi.
Modulation changes one or more radio wave properties to encode a signal. Digital data (1s and 0s) is converted into radio waves with modulation in order for them to be transmitted via Wi-Fi.
This is the most recent IEEE Wi-Fi standard (as of 2024). It introduced EHT technology, MLO, puncturing, and increased theoretical speeds to 46Gbps at the most.
IEEE 802.11be
This early Wi-Fi transmission technology (introduced in 1997) was very redundant. It had speeds of 1-2Mbps and it spreads a data signal across a wider frequency band so that the device has the best chance of receiving the data.
DSSS (Direct Sequence Spread Spectrum)
This feature was introduced with the 802.11n IEEE standard and it combined multiple smaller data frames into one larger transmission instead of sending a single frame at a time and waiting for clearance to send another.
Frame aggregation.
This new feature, introduced with the IEEE 802.11be standard in 2024 allowed for a device to connect to the AP across multiple bands (2.4GHz, 5GHz, and 6GHz) simultaneously.
Multi-Link Operation (MLO)
These are the two layers Wi-Fi or IEEE 802.11 uses in the OSI model.
Layer 1 (Physical Layer) and Layer 2 (Data Link Layer)
This IEEE Wi-Fi standard, released in 2009, relaunched 5GHz Wi-Fi by allowing it to be broadcast simultaneously with 2.4GHz frequency band. It also introduced an early, more unreliable version of MIMO.
IEEE 802.11n
This early Wi-Fi transmission technology improved upon DSSS. It is a mathematically advanced encoding technique used on top of DSSS which transmits by sending multiple bits in a single signal instead of sending one bit at a time.
Complementary Code Keying (CCK)
This Wi-Fi function allows routers to use 5GHz radio channels typically reserved for radar systems—such as military, weather, and aviation radars. It acts as a spectrum-sharing mechanism, enabling Wi-Fi devices to legally operate in these bands by detecting radar signals and automatically switching channels to avoid interference.
DFS (Dynamic Frequency Selection)
This Wi-Fi technology, introduced in 2019, improves upon OFDM. It works hand in hand with something called "Resource Units" to split Wi-Fi channels into smaller sub-channels instead of having one user occupy the entire channel bandwidth.
Orthogonal Frequency Division Multiple Access (OFDMA)
These are the three frequency bands Wi-Fi uses as of 2026.
The 2.4GHz, 5GHz and 6GHz bands.
This Wi-Fi standard introduced CTS-to-Self as a faster alternative to RTS/CTS. It also repurposed the OFDM transmission technology from IEEE 802.11a for the 2.4GHz band.
IEEE 802.11g (2003)
This protocol has been used since Wi-Fi was first introduced to consumers in 199. It's aim is to solve the Hidden Node Problem and it does this by making the device listen to the channel first, waits if it is busy, and then send data after a random backoff time when the channel is clear.
Carrier Sense Multiple Access with Collision Avoidance (CSMA/CA).
This Wi-Fi transmission technology, introduced with the IEEE 802.11a standard in 1999, was originally meant to be used with 5GHz Wi-Fi before being repurposed for 2.4GHz Wi-Fi with IEEE 802.11g in 2003. It splits data into many smaller streams sent at the same time to the device instead of being redundant.
Orthogonal Frequency-Division Multiplexing (OFDM)
These technologies allow the Wi-Fi router/access point to use multiple antennas and send different data streams to different devices. At first, only one device could recieve data at a time, but with the 802.11ac standard, there could be separate simultaneous streams where each device could recieve data at the same time.
Single User Multiple Input and Multiple Output (SU-MIMO); Multi User Multiple Input and Multiple Output (MU-MIMO).
Define beamforming and its two types.
Beamforming is a Wi-Fi transmission technique that focuses the Wi-Fi signal toward a specific, receiving device instead of broadcasting the signal equally in all directions. There is Implicit Beamforming where router guesses the device's location and the more modern Explicit beamforming where the device and router communicate channel info.
These two IEEE Wi-Fi standards were both introduced in 1999. One was significantly faster than the other because it used the 5 GHz frequency band and OFDM transmission technology. The other used the 2.4GHz frequency band and the redundant CCK transmission technology.
IEEE 802.11a and IEEE 802.11b
Without this extra collision avoidance measure, the Wi-Fi router/access point operates in Basic Access Mode.
Request to Send/Clear to Send (RTS/CTS)
Describe all the advantages of 5GHz and 6GHz frequency Wi-Fi compared to the original 2.4GHz Wi-Fi.
Advantages: Less interference and More available channels than 2.4GHz. Disadvantages: More expensive to make devices compatible for, shorter range, and weaker wall penetration
This modulation method was introduced with the IEEE 802.11a standard in 1999 packs data into radio waves by changing the height of the wave (amplitude) and the position/timing of the wave (phase). By combining both,many unique signal patterns (constellation points) are created, where each constellation point represents data.
Quadrature Amplitude Modulation (QAM)
Explain how the Institute of Electrical and Electronics Engineers (IEEE) works while defining what "802" and "802.11" mean.
Engineers and manufacturers meet with manufacturers to propose new add-ons to Wi-Fi. They take a vote on what new additions could be added. As a whole, their operations in the United States are regulated by the FCC. who approves the usage of certain radio bands for Wi-Fi devices. Standards are classifed as 802.11 and then a letter. The 802 part of the name refers to all the agreed upon standards that relate to LAN, PAN, and MAN. 802.11’ refers to the standards that relate to Wi-Fi.