Date: Sat, 02 Apr 2005 21:23:42 -0800 From: Sam Leffler <sam@errno.com> To: Joerg Sonnenberger <joerg@britannica.bec.de> Cc: freebsd-hackers@freebsd.org Subject: Re: which Wifi cards can be used for a WAP? Message-ID: <424F7DDE.80806@errno.com> In-Reply-To: <424F172E.9070201@errno.com> References: <20050402065052.GT44514@numachi.com> <20050402162842.GU44514@numachi.com> <20050402171635.GV44514@numachi.com> <20050402172355.GA1069@britannica.bec.de> <424F172E.9070201@errno.com>
next in thread | previous in thread | raw e-mail | index | archive | help
Sam Leffler wrote: > Joerg Sonnenberger wrote: > >> On Sat, Apr 02, 2005 at 12:16:35PM -0500, Brian Reichert wrote: >> >>> In perusing many of these cards specs, I see many of them offer a >>> 'turbo mode' of 108 Mbps. >> >> >> >> That's a vendor-specific mode. I strongly advice you _against_ using it, >> it's using at least one additional channel and only adds speed for very >> short distances. If you follow the common recommendation of leaving one >> channel before and after the active channel, you end up using at least >> 5 channels for turbo mode compared to three for normal, it's not worth >> the trouble. > > > This is misleading. First turbo mode can only be used in the 2.4G band > on channel 6 and does not impact operation on channels 1 and 11. Any > channels in between already suffer from normal (i.e. non-turbo) use > because the channel spread in the 2.4 band means traffic is visible if > you use the in-between channels. Further, turbo mode (as part of > SuperG) requires that the AP detect non-turbo capable stations and > disable turbo use when such stations are present. I was wrong; turbo mode requires a 40Mhz wide band so when operating on channel 6 it'll splatter 1 and 11. Regardless, compliant AP's are supposed to monitor the air and drop out of turbo if non-turbo traffic is detected. This is part of the Dynamic Turbo component of SuperG and happens transparently to SuperG stations. Sam
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?424F7DDE.80806>