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State of WLAN Support on Linux?
ntropic asks: "I/ve recently bought a Belkin 802.11G USB adapter and was dismayed to find, after a few hours of struggling with it, that there seems to be no one who has managed to get it working under Linux. During the search for clues, it seemed that sum total of Linux support for wireless networking are the linux-wlan project, and the linuxant wrappers for Windows drivers. The former seems to support only Prism chipsets while the latter is a commercial solution, albeit quite an inexpensive one. Is that all, or are there better sources for wireless networking support?"
802.11g under linux is sort of a mess. Wireless cards are getting cheaper and cheaper (in terms of manufacturing) and much of this cheapness is cutting corners, taking more logic off the cards and putting it into software (drivers/firmware).
The vast majority of 802.11g cards out there are almost entirely controlled by software. The frequency, transmit power, etc. I believe the specs to this are all goverend by the FCC (in the US at least, I'm sure most other nations have their own governmental bodies governing what can and can't be done).
As such, opensource drivers are tough as you don't want anyone just modifying the code to change frequencies, up transmit power etc. Also, a number of manufacturers have used "competition" as their reason for keeping things closed.
As a result, the support out there is lumped into a few different chunks:
1) no drivers available
2) atheros drivers (contain a binary HAL object file. This allows them to have a small source component that people can build that links against the binary object which contains the routines to do the various things I mentioned above (basically control the card)
3) opensource driver + firmware (where the firmware component does what the HAL does, but since it's actual firmware loaded to the card, it allows the driver interface to be fully opensourced without revealing too much of what's going on. The intel and prism54 drivers are in this camp.
Basically, if you don't have a prism54 or intel based 802.11g card, you can't use open source drivers, and the drivers will never be included into the kernel because they can't be open sourced. Atheros was nice to release their stuff so that at least their cards are usable.
Every other manufacturer's card users need to hope that their mfg is nice enough to do what atheros does (or if their driver is firmware based, do what intel/intersil[or whoever owns the prism54 stuff now] did by either writing drivers, or helping with it.
It makes it tough if you don't know this ahead of time, but really with 802.11g, you just need to pick the right card and hope. Unfortunately none of this is really very well documented.
For the love of Dog, don't just go out and buy any old crappy wireless card and hope that linuxant or ndiswrapper will support it. All of these slashbots who recommend this route are just remorseful that they didn't do their research before wasting their money on a monopoly-sustaining wireless card.
The worst part is that ndiswrapper and linuxant usually don't allow full use of the card. Sure, you can probably get some connectivity out of it, but sometimes you can't use 802.11g, put the card into promiscuous mode, or use one of the fancy wifi signal-strength and network information applets in KDE and GNOME.
When people ask me about Linux wireless support, I tell them two things:
1) Skip on down to Staples and pick up a Netgear WG511T. It'll cost $40-$50 depending on where in the nation you buy it and what rebates they have going at the time.
2) Boot your favorite distro and install the MadWifi drivers. Configure ath0 for DHCP, sit within range of an access point, and you're good to go.
The madwifi drivers work with Atheros chipsets and evidently Atheros themselves contributed a large amount of the code, so it would be in the interest of all Linux users to support them by checking out the MadWifi compatibility listing and purchasing one of the listed cards. You'll be helping the open source community and getting the most out of your wireless card at the same time.