Re: [Madwifi-users] Card won't transmit?
Status: Beta
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From: Andrew G. <aga...@sk...> - 2004-04-28 15:12:47
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Greg Chesson wrote: > replying to the last part of Andrew's message: > > Andrew Gaffney wrote: > >> Michael Renzmann wrote: >> > <snip> > >> >> Isn't it weird that those signals are n/0? That's the kind of value I >> get when I use driverloader. When I use madwifi, I get n/94. Is it >> just me? >> > > The NDIS and Madwifi drivers and iwconfig all disagree on the meaning > of the signal level parameter returned by the driver. The low-level > hardware > returns rssi which is the relative signal strength above the noise floor. > Many software interfaces believe the hw is returning absolute signal > strength which they then attempt to convert into either rssi or SNR, > getting wierd results. One of the items on the todo list is to get > madwifi > to munge the rssi values from the hw into signal strength so that > applications > can munge it back into relative signal strength. > > Sounds easy, but there is a bit of trickiness involved. > The hw reports rssi on every received frame and on every ack received. > These values vary widely over time. Which value would you like > to have reported to iwconfig, hmmm? Well, you probably want a > time-bounded > average of recent signals, throwing away values older than somewhat. > The noise floor is taken to be a constant -94db. > You can see how this might be an easy fix for stations. > If the driver is in AP-mode, the statistics should probably be kept per > associated station and some new reporting method other than iwconfig > might be needed. I was just commenting that maybe he has a problem with madwifi or the card is acting weird since he isn't getting 'n/94' but 'n/0' for the reported signal strength like madwifi typically does (in my experience). -- Andrew Gaffney Network Administrator Skyline Aeronautics, LLC. 636-357-1548 |