Re: [PATCH] wireless-regdb: recent FCC report and order allows 5850-5895 immediately
From: Seth Forshee <hidden>
Date: 2021-06-08 15:47:31
Also in:
wireless-regdb
On Thu, Dec 03, 2020 at 11:40:30PM +0100, bkil wrote:
The new band is called U-NII-4. The report recommends combining it with 5725-5895 to allow 160 MHz bandwidth, but that's technically not that easy with regdb due to the differing restrictions of the two parts. Marking the line for U-NII-3 NO-OUTDOOR and PTMP-ONLY along with extending its range would be a possible workaround, but this needs to be discussed. I don't see a requirement for TPC, hence reducing EIRP by 3dB is not needed. I've marked it 33dBm (minus 6dB for clients) to cope with 20MHz, but the band can support higher power, though the logic is complicated. The upper subband (5895-5925 MHz) of the new band is reserved for ITS. "We limit unlicensed use to indoor operations in recognition of the potential that ITS licensees may currently be operating" "We also proposed that U-NII-4 devices be permitted to operate at the same power levels as U-NII-3 devices." "For the U-NII-4 band, indoor access point EIRP will be limited to 33 dBm/20 MHz and 36 dBm/40 MHz. When combined with U-NII-3 band spectrum, indoor access point EIRP can scale to 36 dBm for 80 and 160 megahertz channels." "Client devices would be limited to power levels 6 dB below the power limits for access points." "the First Report and Order prohibit U-NII-4 client-to-client communications to protect co-channel incumbent ITS" Signed-off-by: bkil <redacted>
I'm not sure why this was delayed, but it looks like it has finally gone into effect as of June 2: https://www.federalregister.gov/documents/2021/05/03/2021-08802/use-of-the-5850-5925-ghz-band We discussed some of the details before. I'm reading over it again to refresh my memory, so let's revisit the changes I think are required, below.
quoted hunk ↗ jump to hunk
--- db.txt | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-)diff --git a/db.txt b/db.txt index c71a03a..e6dd063 100644 --- a/db.txt +++ b/db.txt@@ -1587,7 +1587,10 @@ country US: DFS-FCC # requirements, we can extend the range by 5 MHz to make the kernel # happy and be able to use channel 144. (5470 - 5730 @ 160), (23), DFS - (5730 - 5850 @ 80), (30) + (5730 - 5850 @ 80), (30), AUTO-BW + # https://www.fcc.gov/document/fcc-modernizes-59-ghz-band-improve-wi-fi-and-automotive-safety-0 + # max. 33 dBm AP @ 20MHz, 36 dBm AP @ 40Mhz+, 6 dB less for clients + (5850 - 5895 @ 40), (27), NO-OUTDOOR, PTMP-ONLY, AUTO-BW
I think we concluded previously that both 5730-5850 and 5850-5895 should have a max bandwidth of 160 MHz to permit use of 160 MHz across these channels. We also discussed using NO-IR for 5850-5895. The regulations forbid active scans, and PMTP-ONLY does not prevent them. NO-IR appears to be the only option which conforms to this restriction, though that will also block running an AP in this range. I also read the max EIRP for clients as 30 dBm without any TPC requirement. Did I overlook something which limits the EIRP to 27 dBm? Thanks, Seth