Wi-Fi Professionals

Wi-Fi Pro Lab

6 GHz Wi-Fi: Wi-Fi 6E and Wi-Fi 7

New spectrum with no legacy devices in it. How much of it you get depends heavily on where you are, which makes 6 GHz the clearest example of why regulation is part of Wi-Fi engineering.

500 MHzUK lower 6 GHz: 5925 to 6425 MHz
1,200 MHzUS: 5925 to 7125 MHz
320 MHzwidest channel (Wi-Fi 7)
about 4.8 cmwavelength

1. DefinitionWhat is the 6 GHz band?

6 GHz Wi-Fi is the use of the 5925 to 7125 MHz range, which regulators have opened in pieces. The UK made 5925 to 6425 MHz (the lower 6 GHz band) available for licence-exempt Wi-Fi. The US made the whole 1,200 MHz available. Wi-Fi in 6 GHz is called Wi-Fi 6E when it is 802.11ax, and 802.11be (Wi-Fi 7) also uses it.

6E is not a new standard. The Wi-Fi Alliance introduced the name “Wi-Fi 6E” on 3 January 2020 for 802.11ax devices that also operate in 6 GHz, and started 6E certification on 7 January 2021. The “E” stands for extended, not for a new PHY.

2. PurposeWhat problem does 6 GHz solve?

  • Spectrum. A large block of new spectrum with room for many channels, including very wide ones.
  • A clean start. Only 802.11ax and later (HE and EHT) devices may operate in 6 GHz, so no legacy 802.11a/b/g/n/ac devices, no slow beacons and no protection overhead.
  • Mandatory modern security. Wi-Fi Alliance certification requires WPA3 in 6 GHz, with protected management frames.
  • The cost: short waves, so limited reach through buildings, and fewer compatible client devices.

3. MechanismChannels, discovery and power classes

Channel numbers run centre = 5950 + 5 x channel MHz, with 20 MHz channels every fourth number (1, 5, 9 … 233 in the US). Widths go up to 320 MHz. Because there are so many channels, clients cannot afford to scan them all. Three discovery tools fix that:

  • Preferred scanning channels (PSC). Every 16th channel (5, 21, 37 … 229) is a PSC, and clients scan those first.
  • Out-of-band discovery. An access point’s radios in other bands announce its 6 GHz radio in the Reduced Neighbor Report element.
  • In-band discovery. Where a 6 GHz AP does not use a PSC, it can send FILS discovery frames or unsolicited probe responses so clients find it faster than waiting for a beacon.

Try this. (1) UK first: only 24 channels fit in 5945 to 6425 MHz at 20 MHz, and just one 320 MHz channel fits. (2) Now US: 59 channels and three 320 MHz channels. (3) At 20 MHz, spot the PSC channels. (4) Notice how few wide channels the UK band holds: this is why regulation matters for design.

4. VisualHow short a 6 GHz wave is

5. MathematicsPath loss, width and rate

At 10 m the free-space loss at 6.2 GHz (channel 49) is 20 + 75.8 – 27.55 = 68.3 dB, and every doubling of distance adds another 6 dB. Walls and floors add loss on top, which is why real-world reach is the main limit. What 6 GHz pays back is width: a 320 MHz EHT channel has 3,920 data subcarriers. One stream of 4096-QAM 5/6 with a 0.8 microsecond guard interval is 3920 x 12 x 5/6 / 13.6 = 2,882.4 Mbps.

6. Techniques over timeFrom rules to Wi-Fi 7

6 GHz has a short history, and most of it is regulatory. The timeline below changes with your regulatory domain: UK steps first, with the US available on click.

Go deeper. The waveform here is OFDM with OFDMA. The OFDM topic shows step by step how bits become subcarriers.

  • HE (Wi-Fi 6E). OFDMA, 1024-QAM, and up to 160 MHz.
  • EHT (Wi-Fi 7). 4096-QAM, 320 MHz channels and multi-link operation. Wi-Fi CERTIFIED 7 was announced on 8 January 2024.
  • UHR (Wi-Fi 8, in progress). The 802.11bn project is focused on reliability and coordination. It is not final, so treat what you read about it as provisional.

7. Rules and regulationsUK Ofcom first, then the EU and the US

The rules for 6 GHz differ most between the UK and the US. The UK and the EU have low-power indoor (LPI) and very low power (VLP) classes in the lower band. The US has indoor low-power, and standard-power operation under AFC. Switch between the three domains to compare.

8. Real-world behaviourWhat goes wrong in 6 GHz

  • Client coverage. A phone that supports 6 GHz may still not support 320 MHz, and a client that reaches 6 GHz in one country may have it disabled in another because of the regulatory domain it was built for.
  • Range. A 6 GHz signal that has crossed two walls is often weak enough that a client falls back to another band. Test with a real handset, not an access point’s spec sheet.
  • Discovery. A 6 GHz radio on a non-PSC channel may be slow to appear, because clients scan PSCs first.
  • Power class. A low-power indoor AP is not allowed outside, and a very-low-power device has a power budget a tenth of a low-power indoor access point’s.
  • Marketing versus reality. “Wi-Fi 6E” or “Wi-Fi 7” on a box says what the radio can do, not what the regulator in your country permits.

Practical validationProve it in a capture and on a spectrum analyser

Reading about a band is one thing; seeing it in your own evidence is the skill. These checks work with any monitor-mode capture:

  • Which band is a client on? wlan_radio.frequency > 5900
  • Out-of-band discovery, in a beacon from the AP’s other radios: wlan.tag.number == 201 (Reduced Neighbor Report).
  • Security: 6 GHz networks should show WPA3-SAE or OWE and protected management frames in the beacon’s RSN element.
  • Check which standard the client negotiated: look for HE or EHT capabilities in the association request.
  • Question to answer: with one AP, at what distance and through how many walls does a phone leave 6 GHz?

Check your understandingQuick quiz

ReferencesSources and further reading

IEEE standards are paid documents, so the link above goes to the publisher. Where a topic names a clause or table of IEEE Std 802.11-2020, its facts were checked against that clause; amendment dates come from the IEEE 802.11 Working Group’s public timelines. Regulations change, so check the regulator for the current text.