Re: [PATCH] wireless-regdb: allow 320MHz channel width for Russia

[Louis Kotze <loukot@gmail.com>]

ChenYu, thanks for the ping on this one.

Cross-checked against SCRF 22-65-05 (which added 5925-6425 MHz to the
2007 spectrum allocation, Appendix 2):

  Section 2 ("Devices with direct sequence spread spectrum and other
  modulation types") for 5925-6425 MHz specifies:
    LPI: max EIRP 200 mW, max PSD 10 mW/MHz, indoor only,
         with automatic power control
    VLP: max EIRP 25 mW, max PSD 1.3 mW/MHz, indoor only

  No channel-width restriction is specified for this category. The
  only width cap (less than 20 MHz) applies to the FHSS subsection,
  not to DSSS / 802.11-style modulation.

  SCRF 23-68-03 §3.1 later replaced "automatic power control" with
  "LBT mode" globally in that appendix, which the 802.11 CCA mechanism
  satisfies.

320 MHz operation at the 200 mW LPI cap gives 0.625 mW/MHz, well under
the 10 mW/MHz PSD ceiling, so the wider channel stays compliant on
both EIRP and PSD limits. Per regdb convention of encoding the
spectrum allocation ceiling and leaving per-standard equipment
certification to drivers, the bandwidth widening is sound.

Reviewed-by: Louis Kotze <loukot@gmail.com>

Note that the patch base predates the recent RU power update (commit
6873bfe in wens/wireless-regdb), which changed 5925-6425 from 100 mW
to 200 mW, so this needs a rebase on current HEAD before it can be
applied.

Regards,
Louis