Supported Chipsets

One of the most important choices you face when building a CUWiNware node is what wireless NIC to buy. Wireless NICs use a variety of chipsets depending on the the manufacturer that makes them. The chipset that your wireless NIC uses must have drivers in NetBSD that support Ad-Hoc mode.

Theoretically different chipsets can be used in different nodes on a CUWiNware network as long as they are supported by NetBSD but because of various bugs/quirks in the firmwares of various chipsets, it is often best to standardize on a single supported chipset for all the nodes in your network.

Chipsets

Intersil Prism - The prism (version 2, 2.5, or 3) chipset is used in some PCMCIA and PCI cards manufactured by D-Link, Proxim, SMC, and others. This chipset is well supported in Ad-Hoc mode with no real bells and whistles. This may be the best chipset available if low cost PCI cards are needed for low-resource nodes.
Atheros - Atheros makes the most advanced 802.11x NICs currently available. This is the chipset currently recommended by the CUWiN team. Most tri-mode a/b/g cards on the market use the Atheros chipset. The Atheros chipset features a Hardware Abstraction Layer which puts most of what would traditionally be in the firmware into software. This means that when/if the interface to the cards is fully opened up to programmers, arbitrary control of power levels and other low level features will be possible. Because future versions of CUWiNware will take advantage of this fine grained control we recommend investing in cards with this chipset now. Atheros cards may be a bit more expensive than some of their competitors and the drivers for the Atheros cards are not as mature as those for the Prism cards so there may be bugs, but these drivers are being actively developed and debugged by the CUWiN team.
Hermes - Most cards made by Orinoco, Lucent, WaveLAN, and Proxim use the Hermes chipset. These cards have very good sensitivity with low power radios and they are supported in NetBSD but they suffer from serious firmware problems relating to their IBSS ids. The IBSS id needs to be the same throughout the mesh but cards with this chipset often "split" the IBSS in a way that can only be fixed by rebooting all nodes on the network in a certain order. This chipset should generally be avoided for any Ad-Hoc network as just one Hermes chipset mixed in with other nodes can cause a serious network split. Firmware upgrades do not appear to completely solve this problem. Aironet/Cisco chipsets have the same problem.
Other Chipsets - Development of drivers for new chipsets is constantly in progress. Some manufacturers publish the specs for their hardware which makes driver development fairly straightforward. Other manufacturers keep their specifications proprietary which means that NetBSD developers have to reverse engineer the interfaces. Support for the ADMTek ADM8211A is available now and support for other ADMTek chipsets such as ADMtek ADM8211C/CR is expected soon. Support for the Realtek RTL8180 chipset has also been added.