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Wi-Fi Complete Series · Part 3 of 6 Wi-Fi Channels & Frequencies: 2.4 – 5 – 6 GHzChannel planning, bandwidths and non-overlapping channels for a congestion-free WLAN 2.4 GHz Channels · 5 GHz DFS Channels · 6 GHz Band · Channel Width 20/40/80/160/320 MHz |
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Contents
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Channel & Channel Width Basics
A Wi-Fi channel is a defined frequency range within the available spectrum. The channel width determines how much spectrum it occupies and the maximum possible data rate.
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Channel Widths & Effect: 20 MHz — Standard width, lowest interference 40 MHz — Double throughput, more overlap 80 MHz — Typical for 5 GHz WLAN 160 MHz — Wi-Fi 5/6, high throughput 320 MHz — Wi-Fi 7 only, 6 GHz band only |
Rules of Thumb: Always use 20 MHz in the 2.4 GHz band In 5 GHz with high density: 40 or 80 MHz In 6 GHz: 80 or 160 MHz (little competition) Wider channels = higher throughput but fewer non-overlapping channels In multi-AP: narrow channels + more APs |
2.4 GHz Band: Channels 1–13
Germany/EU has 13 channels in the 2.4 GHz band. Each channel occupies 22 MHz with a 5 MHz raster — most channels overlap heavily. Only channels 1, 6 and 11 are non-overlapping at 20 MHz width. In the EU, channel 13 can serve as a fourth non-overlapping channel (1-5-9-13 scheme).
| Channel | Centre Frequency | Frequency Range (22 MHz) | Recommendation |
| 1 | 2,412 MHz | 2,401–2,423 MHz | ✓ Non-overlapping |
| 2 | 2,417 MHz | 2,406–2,428 MHz | ✗ Overlaps with 1+6 |
| 3 | 2,422 MHz | 2,411–2,433 MHz | ✗ Overlaps |
| 4 | 2,427 MHz | 2,416–2,438 MHz | ✗ Overlaps |
| 5 | 2,432 MHz | 2,421–2,443 MHz | ✗ Overlaps |
| 6 | 2,437 MHz | 2,426–2,448 MHz | ✓ Non-overlapping |
| 7 | 2,442 MHz | 2,431–2,453 MHz | ✗ Overlaps |
| 8–10 | 2,447–2,457 MHz | — | ✗ Overlaps |
| 11 | 2,462 MHz | 2,451–2,473 MHz | ✓ Non-overlapping (also in USA) |
| 12 | 2,467 MHz | 2,456–2,478 MHz | EU only (edge channel) |
| 13 | 2,472 MHz | 2,461–2,483 MHz | ✓ EU only, rarely used — for 4-channel scheme (1-5-9-13) |
Recommendation: Always use channels 1, 6 and 11 in the 2.4 GHz band (three-channel scheme). Place additional APs on channel 1 or 11 rather than intermediate channels.
5 GHz Band: DFS Channels & Channel Planning
The 5 GHz band offers up to 19 non-overlapping channels at 20 MHz in the EU. Key concept: DFS (Dynamic Frequency Selection) — certain 5 GHz channels are shared with weather and military radar. If a WLAN AP detects a radar signal, it must switch channels, causing brief connection interruptions.
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UNII-1 (5,150–5,250 MHz) Channels 36, 40, 44, 48 No DFS, indoor only Max. 200 mW EIRP Best for indoor deployments |
UNII-2 (5,250–5,350 MHz) Channels 52, 56, 60, 64 DFS + TPC required Radar scan on startup Higher TX power allowed |
UNII-2 Extended (5,470–5,725 MHz) Channels 100–140 DFS + TPC required Many non-overlapping channels Popular for multi-cell deployments |
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UNII-3 (5,725–5,850 MHz) Channels 149, 153, 157, 161, 165 No DFS (partially restricted in DE) Up to 1 W EIRP Popular in consumer routers |
80 MHz Channel Groups (Wi-Fi 5/6): 36+40+44+48 = 80 MHz block 52+56+60+64 = 80 MHz block 100+104+108+112 = 80 MHz block etc. — every 4 × 20 MHz channels form one 80 MHz super-channel |
6 GHz Band (Wi-Fi 6E & Wi-Fi 7)
The 6 GHz band was opened for Wi-Fi in the EU from 2021 (indoor: 5,925–6,425 MHz = 500 MHz). Some countries (USA, Brazil) allow up to 1,200 MHz (5,925–7,125 MHz).
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Advantages: ✓ Almost no existing interference ✓ No DFS required ✓ Up to 24 non-overlapping 80 MHz channels (EU) ✓ 320 MHz channels for Wi-Fi 7 ✓ Maximum data rates achievable |
Limitations: ⚠ Indoor only (EU regulation, max. 23 dBm EIRP) ⚠ Short range (higher frequency = more attenuation) ⚠ Requires Wi-Fi 6E or Wi-Fi 7 devices ⚠ Older clients still use 2.4/5 GHz ⚠ Outdoor use heavily restricted in EU |
Channel Planning in Practice
| Scenario | Recommended Setting | Reason |
| Single home router (2.4 GHz) | Ch. 1, 6 or 11 (manual) | Use Wi-Fi analyser to pick least congested |
| Single router (5 GHz) | 80 MHz, auto or Ch. 36/40/44/48 | UNII-1 channels without DFS = stable connection |
| Multi-AP (2.4 GHz) | Channels 1, 6, 11 rotating; 20 MHz fixed | No 40 MHz in 2.4 GHz band; maximum channel purity |
| Multi-AP (5 GHz, high capacity) | 20 or 40 MHz; many different channels | More APs with narrow channels > few APs with wide channels at high density |
| High-density (Wi-Fi 6) | 20/40 MHz + OFDMA enabled | OFDMA distributes channel resources efficiently; narrow channels reduce co-channel interference |
FAQ
| Which Wi-Fi channel is the best? |
| There is no universally "best" channel — it depends on which channels neighbours use. In 2.4 GHz: analyse channels 1, 6 and 11 and manually set the least congested one. In 5 GHz, channels 36–48 (UNII-1) are more stable because they don't require DFS. |
| What is DFS and why does my WLAN suddenly disconnect? |
| DFS (Dynamic Frequency Selection) forces 5 GHz WLAN devices to switch channels when a radar signal is detected. This causes a brief pause (typically 1–10 seconds). Avoid DFS: use UNII-1 channels (36–48) which don't require DFS. |
| When does the 6 GHz band really pay off? |
| The 6 GHz band is worthwhile when deploying Wi-Fi 6E or Wi-Fi 7 devices requiring high data rates or low latency (AR/VR, video conferencing in production). In a standard office environment with mixed devices, short-term gains are limited as most clients don't yet support this band. |
Wi-Fi Analysis Tools & Enterprise Access PointsFrom professional site survey tools to enterprise APs with channel optimisation — our B2B sales team assists with selection and planning. Phone: +49 (0)7666 / 88499-0 · E-Mail: sales@industry-electronics.com |
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