The devices, the drivers - other

Jean Tourrilhes

13 April 04

The who's who of Wireless LANs under Linux.

This section contains information about some devices which don't have a specific entry in one of the previous three sections.

5.1 Not supported (the hall of shame)

Netwave AirSurfer plus (in 802.11 mode), BayStack 650 : Now that a driver for the BayStack 660 is available, it should be quite easy to make a driver for those cards, by reusing the physical layer parts in the AirSurfer plus driver. FreeBsd seems to have a driver for this device... This product has been discontinued.

RadioLan has a 10 Mb/s at 5 GHz product, rather very short range and no Linux drivers. This product has been discontinued.

WebGear Aviator 900 MHz : connect to the parallel port and offer cable replacement solution. No functional Linux driver. This product has been discontinued.

The IBM Wireless LAN Entry is a discontinued product that may be sometime found for a very very low price. Unfortunately, there is no working driver for those and information on the device is impossible to find. This product has been discontinued.

Both TI and Broadcom are very unfriendly toward Linux. They don't release Linux drivers or any information to help build Linux drivers for their cards despite using Linux drivers internally and in some products. Open Source drivers for those cards exist, based on reverse engineering, but because those drivers probably will never support all features/models of those cards and because of the overall attitude of those companies, you may want to avoid those cards.

Conexant (formerly Intersil) seems to have reverted their previously pro-Linux approach to ignoring the Linux community (which did help them so much).

5.2 Win32 drivers

Two packages enable the use of Win32 wireless LAN drivers under Linux :

DriverLoader : http://www.linuxant.com/driverloader/
NdisWrapper : http://ndiswrapper.sourceforge.net/

DriverLoader is commercial, whereas NdisWrapper is GPL. Both seems to work with a wide range of Win32 drivers and Linux features, for example both support Broadcom, TI and Intel drivers, and most Wireless Extensions including Wireless Scanning.

Some people have strong objections to using Win32 drivers under Linux. Obviously, such a solution is restricted to the i386 architecture, and make use of a lot of binary code. Also, some less used Wireless Extensions features are not available in the NDIS specification (such as link quality, noise level, iwspy, master and monitor mode).

5.3 A note on driver licenses

Donald Becker's web page alerted me on the license and copyright issues for networking drivers (see http://www.scyld.com/expert/modules.html#legal for details). If you just plan to use the driver in your Linux PC, there should be no problem, but if you plan other use of the drivers you should pay attention to the exact license the driver come in.

Most drivers are GPL, which prevent their use with non-GPL kernels (so commercial operating systems can't reuse the code) and prevent to use portions of the source in non-GPL drivers, except with the explicit authorisation from the author.

Some other drivers come with a binary library, which restrict its potential use (the driver can't be ported to other architectures).

This may be restrict what you can do with those drivers, but those people have spend long nights and week ends convincing the hardware manufacturer to release information, writing and debugging the code, so please respect their copyrights and decisions.

5.4 More information on the devices, other Wireless LANs

You will notice that I don't give too much information on the different devices. The web page of each vendors usually contain the full specification of the products they sell.

They are many more products available than the ones that I've listed (which are the most common). If your favourite wireless LAN is not listed above, either there is no driver under Linux that I know of, or it is an OEM version of one of these (same hardware under a new brand).

To have a good picture of all the devices available and their characteristics, you should redirect your favourite browser to :

http://hydra.carleton.ca/info/wlan.html

5.5 Other Wireless technologies

5.5.1 Wireless bridges

Wireless bridges allow to connect different networks via radio, their goal is to replace a dedicated leased line (T1, for example). They usually offer longer distance through directional antennas, and are peer to peer.

These devices are a totally independent box (like other bridges, routers or gateways) and not a card to plug in your PC, so have no interactions with Linux.

5.5.2 Radio Amateur and AX25 (HAM)

These devices are quite specific and are described in their own howto.

5.5.3 Infrared

Apart from the remote control stuff, most infrared devices are IrDA compliant. IrDA defines a full lightweight protocol stack on top of very cheap and simple hardware, and is optimal for short ad-hoc transactions (using Obex for example). TCP/IP networking over IrDA can be done using PPP over IrComm, IrLAN or IrNET (all of them point-to-point solutions).

More information on IrDA for Linux is available at :

http://irda.sourceforge.net/
http://www.tuxmobil.com/howtos.html
http://www.hpl.hp.com/personal/Jean_Tourrilhes/IrDA/IrDA.html

There is also some real Wireless LANs using diffuse infrared (no more peer to peer), but I don't have much information on these.

5.5.4 BlueTooth

BlueTooth is a radio standard heavily influenced by IrDA and USB, and offers the functionality of a wireless USB and serial cable replacement (see section 8 for a more complete description). BlueTooth defines its own protocol stack as well, and offers the possibility to create long term binding between devices (attach wirelessly peripherals to a phone or a PDA). TCP/IP networking over BlueTooth can be done using PPP over RfComm or PAN (BNEP).

More information on BlueTooth for Linux is available at :

http://bluez.sourceforge.net/
http://sourceforge.net/projects/bluetooth/
http://www.holtmann.org/linux/bluetooth/
http://www.hpl.hp.com/personal/Jean_Tourrilhes/bt/

5.5.5 Digital mobile phones and other radio WAN

Again, this is quite different from Wireless LANs. I don't know much about those devices, except the usual generalitie.

Digital mobile phones (GSM, TDMA, CDMA, PHS) very often allow data connections (slow and expensive). Most of them offer a standard serial interface with an extended AT command set, so can be configured like a normal modem : PPP over the serial port.

Some Nokia GSM phones use a kind of half winmodem interface where the upper layer handling is done by the host. For these phones you need gnokii (http://gnokii.org). This package also provide tools to play with various extra features of the phone (SMS, address book...).

Of course, the ultimate geek challenge is to use IrDA (see section 5.5.3) to connect your mobile phone to your laptop. That's done with PPP over IrComm or gnokii.

In most cases, Wireless WANs such as CDPD cards, the Metricom Ricochet and ARDIS should use modem interface as well.

next

Project hosted and sponsored by :