Re: [Madwifi-devel] Survey: What are you using MadWifi for, and why?

[Jouni Malinen <j@w1.fi>]

On Wed, Nov 18, 2009 at 02:08:16PM -0800, Luis R. Rodriguez wrote:
> Are you aware of any regulatory rules which prohibit narrower
> channels? It just seems odd.

I don't remember any rules that would explicitly do that, but there may
be some implicit limitations due to the slower TX rate. I don't know
whether this would hit anywhere, but at least quarter width channel with
1 Mbps TX rate and maximum frame length might get pretty close to some
maximum TX-without-sensing limits. Though, that is less likely to be an
issue on 5 GHz band due to 6 Mbps minimum TX rate even at quarter
channels could be fast enough. There could also be some rules that state
the minimum TX rate, so there could potentially be need to change
supported rate sets and/or fragmentation threshold in some corner cases.

Actually, even with 6/4 Mbps TX rate, the channel sensing rule in Japan
(carrier sense every 4 ms) (if that rule is still valid.. haven't
really checked), we could hit the limit with maximum frame length.
 
-- 
Jouni Malinen                                            PGP id EFC895FA