developer | a11349d | 2022-06-02 01:06:38 +0800 | [diff] [blame] | 1 | From 888da5f48030e45ce14f43a2bf7be07ec79b60d4 Mon Sep 17 00:00:00 2001 |
| 2 | From: Dennis Bland <dennis@dbperformance.com> |
| 3 | Date: Wed, 20 Apr 2022 20:56:38 -0600 |
| 4 | Subject: [PATCH 2/5] Regulatory update for 6 GHz operation in United States |
| 5 | (US) |
| 6 | |
| 7 | With the 6 GHz band (U-NII-5, U-NII-6, U-NII-7, U-NII-8) in USA, the FCC |
| 8 | introduces the concept of a fixed PSD (Power Spectral Density) for all |
| 9 | supported 6 GHz channel widths for LPI (Low Power Indoor) environments. |
| 10 | Wider channel widths have a higher noise floor, therefore specifying a |
| 11 | fixed PSD allows wider channels to operate at a higher EIRP to maintain |
| 12 | the same S/N ratio as smaller channel widths. |
| 13 | |
| 14 | While the 6 GHz specification also allows a "Standard" power mode with |
| 15 | higher EIRP and PSD limits, these devices are also required to employ |
| 16 | AFC (Automatic Frequency Coordination) which normally requires GNSS. |
| 17 | Currently there is no way to specify different EIRP and PSD levels for |
| 18 | APC and non-APC devices. Therefore, only LPI mode is considered here. |
| 19 | |
| 20 | LPI requires non-client (AP) devices to have a maximum PSD of 5 dBm/MHz |
| 21 | and a maximum EIRP of 30 dBm. LPI requires client (STA) devices to have |
| 22 | a maximum PSD of -1 dBm/MHz. The maximum channel width is 320 MHz. |
| 23 | |
| 24 | The following equation is used to calculate the EIRP from the PSD and |
| 25 | channel width: |
| 26 | |
| 27 | EIRP = PSD + 10*log(channel width in MHz) |
| 28 | |
| 29 | Using the maximum PSD values of 5 and -1 for APs and STAs respectively, |
| 30 | the EIRP in dBm for a given channel width can be calculated: |
| 31 | |
| 32 | Channel Width (MHz) AP STA |
| 33 | ------------------------------------------------ |
| 34 | 20 18 12 |
| 35 | 40 21 15 |
| 36 | 80 24 18 |
| 37 | 160 27 21 |
| 38 | 320 31 (max 30) 25 (max 24) |
| 39 | |
| 40 | For channel widths up to 160 MHz, the maximum PSD is the limiting factor. |
| 41 | For the 320 MHz channel width, the maximum EIRP is the limiting factor. |
| 42 | |
| 43 | Unfortunately, because there is currently no mechanism to specify |
| 44 | different power levels for AP and STA modes, and for different channel |
| 45 | widths, the smallest value has to be selected, which is 12 dBm. This |
| 46 | will likely cause connectivity problems with larger channel widths until |
| 47 | these additional parameters can be added. |
| 48 | |
| 49 | 6 GHz operation on oil platforms, vehicles, boats, trains, and drones is |
| 50 | prohibited except on commercial aircraft above 10,000 feet altitude. |
| 51 | An IR (Initiate Radiation) restriction is mentioned in the 6 GHz |
| 52 | specification. |
| 53 | |
| 54 | Signed-off-by: Dennis Bland <dennis@dbperformance.com> |
| 55 | Signed-off-by: Seth Forshee <sforshee@kernel.org> |
| 56 | --- |
| 57 | db.txt | 3 +++ |
| 58 | 1 file changed, 3 insertions(+) |
| 59 | |
| 60 | diff --git a/db.txt b/db.txt |
| 61 | index 062ad8a..fcdc74a 100644 |
| 62 | --- a/db.txt |
| 63 | +++ b/db.txt |
| 64 | @@ -1649,6 +1649,9 @@ country US: DFS-FCC |
| 65 | # https://www.federalregister.gov/documents/2021/05/03/2021-08802/use-of-the-5850-5925-ghz-band |
| 66 | # max. 33 dBm AP @ 20MHz, 36 dBm AP @ 40Mhz+, 6 dB less for clients |
| 67 | (5850 - 5895 @ 40), (27), NO-OUTDOOR, AUTO-BW, NO-IR |
| 68 | + # 6g band |
| 69 | + # https://www.federalregister.gov/documents/2020/05/26/2020-11236/unlicensed-use-of-the-6ghz-band |
| 70 | + (5925 - 7125 @ 320), (12), NO-OUTDOOR, NO-IR |
| 71 | # 60g band |
| 72 | # reference: section IV-D https://docs.fcc.gov/public/attachments/FCC-16-89A1.pdf |
| 73 | # channels 1-6 EIRP=40dBm(43dBm peak) |
| 74 | -- |
| 75 | 2.29.2 |
| 76 | |