Wi-Fi Channel Allocation
Wi-Fi channel allocation refers to the standardized assignment of frequency channels within the 2.4 GHz, 5 GHz, and 6 GHz bands. These allocations are essential for ensuring coexistence, minimizing interference, and achieving regulatory compliance across regions and device types.
Scope and Application
Wi-Fi operates in three key frequency bands:
| Band | Frequency Range | Channel Numbers | Notes |
|---|---|---|---|
| 2.4 GHz | 2400–2483.5 MHz | 1–13 (14 in Japan) | 5 MHz spacing, partial overlap |
| 5 GHz | 5150–5850 MHz (UNII 1–3) | 36–64, 100–144, 149–165 | DFS and TPC required in UNII-2; outdoor limits vary |
| 6 GHz | 5925–7125 MHz (UNII 5–8) | 1–233 | Used in Wi-Fi 6E and Wi-Fi 7; AFC required for standard-power |
| Property | Details |
|---|---|
| 2.4 GHz Band |
Frequency: 2400–2483.5 MHz Channels: 1–13 (14 in Japan) Notes: 5 MHz spacing, partial overlap |
| 5 GHz Band |
Frequency: 5150–5850 MHz (UNII 1–3) Channels: 36–64, 100–144, 149–165 Notes: DFS and TPC required in UNII-2; outdoor limits vary |
| 6 GHz Band |
Frequency: 5925–7125 MHz (UNII 5–8) Channels: 1–233 Notes: Used in Wi-Fi 6E and Wi-Fi 7; AFC required for standard-power |
The exact availability and restrictions of channels vary by country and are defined by authorities such as the FCC (USA), ETSI (EU), and ISED (Canada).
Technical Principles
Channel Spacing
2.4 GHz: Uses 5 MHz spacing; channels significantly overlap unless separated by at least 25 MHz. The standard non-overlapping channels are 1, 6, and 11.
5 GHz / 6 GHz: Use 20 MHz base spacing; support channel bonding into wider bandwidths (e.g., 40, 80, 160, or 320 MHz).
Channel Bandwidth Modes
HT20/40 (Wi-Fi 4 / 802.11n)
VHT80/160 (Wi-Fi 5 / 802.11ac)
EHT320 (Wi-Fi 7 / 802.11be)
Channel Center Frequencies
Each channel number corresponds to a fixed center frequency.
Example: Channel 36 = 5180 MHz in the 5 GHz band.
Regulatory Considerations
DFS (Dynamic Frequency Selection) and TPC (Transmit Power Control) are required for specific 5 GHz sub-bands (UNII-2A and UNII-2C) to prevent interference with radar systems.
AFC (Automated Frequency Coordination) is mandatory for standard-power devices in the 6 GHz band. It ensures coexistence with licensed incumbent services (e.g., fixed microwave links).
Indoor/outdoor use and power limits must be enforced through firmware and hardware configurations in accordance with regional rules.
Device Certification
For regulatory approval, Wi-Fi-capable devices must demonstrate:
Use of allowed channels per region
Proper DFS response and radar detection (if applicable)
Compliance with channel bandwidth declarations and Occupied Bandwidth limits
Enforcement of indoor/outdoor restrictions and power limits
Testing standards include:
United States
FCC §15.247 – Requirements for DSSS, FHSS, and digital modulation in 2.4 GHz and 900 MHz bands
FCC §15.407 – Technical rules for 5 GHz U-NII bands, including DFS, TPC, and emission limits
Europe
EN 300 328 – Harmonized standard for 2.4 GHz WLAN, Bluetooth, and other ISM-band systems
EN 301 893 – Requirements for 5 GHz Wi-Fi (DFS/TPC, spectrum sharing, channel access)
EN 303 687 – New standard for 6 GHz Wi-Fi (Wi-Fi 6E/7), covering LPI, VLP, and AFC use cases
Canada
RSS-247 – Certification standard for 2.4 GHz and 5 GHz license-exempt WLAN and Bluetooth devices
Tool Support:
Use the Wi-Fi Channel Explorer to visualize allowed channels, center frequencies, DFS status, and regional availability across the 2.4 GHz, 5 GHz, and 6 GHz bands.