Wireless Frequencies

Different frequency tands that are used to transmit and recive the radio waves used by the wireles networks to send data.

Each frquench band has more or less frequency speeds and are regulated by govt agencyes.

2.4 ghz - one fo the most widly used requencies for qireless netowrk in and is known dfor its long-rang and better penetrations frequencies from 2.400 to 2.495

then it’s deviced into channels

Channel - physical meduim through which the wireless networks can send and recive data. uses a oertion of the reequencies to divice it into sections. 11 13 or 14 .. there are overlaps also.

us 1 - 11

jaan 1 - 12

world all frequencies.

5ghz Contains frequencies from 5.725 GHz AND 5.875, and ther eare 24 non-overlapping channels most of the 20 MHZ per channel when working is a 5 GH based 802/11 wireless network.

less interference,

higher performance. has a shorter rhange than 2.4 creates

Channel bonding- creates a wider chnnel can bond up to 8 channels . using channel leads to increased channel widths.

6ghz relativyty new spectum opened up for wi-fi use that offers even more channels and bandwidth to allow for faster connections. 5.925 to 7.125 government

20,40, 80, 160 mhz channels.

Regulatons: govt. allocates parts of the spectrum for our use.

802.11a origionally caused issues with military radar systems.

802.11h starndard was developed to comply with European regulations for wireless regulation.

DFS( Feature that requires devices to activly monitray for radar systems.

TPC (Allows deices to adjust transmitting power to the minimum required across different frequency bands.

Band steering - Technology used in wireless network to optomize the distribution of client devices across the fequency band.

2.4

5ghz higher frequency

6 Ghz

Wireless Frequency Bands (N10-009)

2.4 GHz Band

Range: 2.400 – 2.495 GHz
Pros: Longer range, better wall penetration.
Cons: More interference (crowded with Bluetooth, microwaves, cordless phones).
Channels:
- US: 1–11
- Japan: 1–14
- World: 1–13
Only channels 1, 6, 11 are non-overlapping in the US.
Exam Tip: 2.4 GHz = slower but longer range.

5 GHz Band

Range: 5.725 – 5.875 GHz (varies by country/regulation).
Pros: More channels, less interference, higher throughput.
Cons: Shorter range, less penetration through walls.
Channels: 24+ non-overlapping (20 MHz each).
Channel Bonding: Can combine 2, 4, or 8 adjacent channels → 40, 80, or 160 MHz wide for more bandwidth.
Used in 802.11a/n/ac/ax.

6 GHz Band (Wi-Fi 6E / Wi-Fi 7)

Range: 5.925 – 7.125 GHz.
Newest band opened for Wi-Fi use.
Adds 14 additional 80 MHz channels or 7 additional 160 MHz channels.
Supports 20, 40, 80, 160 MHz channels (and 320 MHz in Wi-Fi 7).
Pros: Faster speeds, very low latency, lots of spectrum.
Cons: Shortest range of the three bands.

Regulatory Features

DFS (Dynamic Frequency Selection):
- Requires devices to monitor for radar signals on DFS channels.
- If radar is detected, Wi-Fi must move to another channel.
TPC (Transmit Power Control):
- Devices adjust power to minimum required.
- Reduces interference, complies with government limits.
802.11h:
- Amendment to 802.11a to comply with European radar regulations.
- Implements DFS + TPC.

Band Steering

Technology that automatically moves clients to the optimal band:
- Pushes newer devices from 2.4 GHz → 5 GHz or 6 GHz.
- Balances load and improves performance in mixed environments.

✅ Exam Must-Knows:

2.4 GHz = long range, 3 non-overlapping channels (1, 6, 11 US).
5 GHz = more channels, less interference, shorter range.
6 GHz = newest, fastest, but shortest range.
DFS + TPC = regulatory compliance with radar systems.
Band Steering = optimizes client distribution across bands.

⚡ Flashcards

Q: Which Wi-Fi band penetrates walls best?

A: 2.4 GHz.
Q: What channels are non-overlapping in 2.4 GHz (US)?

A: 1, 6, 11.
Q: What Wi-Fi standard introduced 6 GHz use?

A: Wi-Fi 6E.
Q: What does DFS protect against?

A: Interference with radar systems.