[conspire] 802.11g chips, miniPCI to PCI, connectors, bundles

[Daniel Gimpelevich]

On Wed, 26 Sep 2007 11:30:19 -0700, Rick Moen wrote:

> Hi, Daniel.  Per your excellent suggestion, I went to Halted to shop. 
> Yes, they do have some relevant stuff still in stock.  I bought
> something I _might_ use, for only $12.50:  A fairly generic miniPCI to
> PCI adapter card (goes into a host's PCI bus, accepts miniPCI cards).
> I'd like to consult your opinion on further purchases.
> 
> The particular part I've so far bought has one semi-serious problem:  It
> has a blank backpanel PCI faceplate, without anywhere for antennas to
> connect on the back panel.  That is a drawback, but at least it _should_
> function otherwise with any miniPCI card, and is very cheap.
> Presumably, you would _somehow_ connect from a pin on the card (whatever 
> card one uses) to some coax cable, and thus to an antenna.  I have some 
> qualms about practical problems with cross-connections -- see also
> below.)

Whoops. I could not see that potentially frustrating characteristic
through their somewhat weathered display case. If I come across suitable
replacement faceplates, I'll try to remember to point you in their
direction.

> o  One question is what miniPCI WiFi card to buy.ng /etc/bootparamsi 
> o  Another is whether I should buy one particular bundle Halted offers.
> 
> Your opinions would be valued.
> 
> Halted currently stocks three miniPCI WiFi cards.  Of course, plenty
> other models are available elsewhere, such as Intel 3945.  (This is an
> area of Linux driver support I haven't researched lately.  My casual
> current prejudice, having not done research, is that Intel 3945 is the
> best-compromise current production WiFi chip used in miniPCI cards,
> from the perspective of Linux users.)

The ipw3945 driver works OK as a wi-fi client if you don't mind the binary
blob involved. AFAIK, it is not currently possible to use it as an AP with
any off-the-rack software. Rather rules it out, wouldn't you think?

> Halted stocks:
> 
> o  Conexant Prism World Chipset,802.11A/B/G, 14-17.5 dBm, $49
> o  Atheros AR5004 Chipset, 802.11A/B/G, 17-18 dBm, $55
> o  Conexant Prism Javelin Chipset, 802.11B/G, 17dBm, $45
> 
> (If the Conexant chips' descriptions, above, turn out to unusably vague,
> I wouldn't be the least bit surprised.  They're transcribed verbatim
> from Halted's signage.  Better data can no doubt be gleaned from the
> cards themselves.)

The Javelin is the isl3886. Currently, that chipset is apparently not
usable for anything without ndiswrapper. See:
http://prism54.org/newdrivers.html

As for the Prism WorldRadio:
http://prism54.org/punbb/viewtopic.php?pid=5336

> The second of those two miniPCI cards (Atheros AR5004) is also 
> available premounted in a slightly different miniPCI to PCI converter
> chassis, one with an BNC antenna connector on the PCI card back panel,
> and a connector cable from the Atheros card's antenna pin to the BNC
> connector on the PCI back panel.  In one sense, this is a very tempting
> bundle, because (aside from possible driver issues) everything just 
> works without worry about finding exotic connectors or crossconnects.
> I'm guessing that one would simply add a run of 50 ohm coaxial cable, 
> of appropriate length, with BNC conectors on each end, and put an
> antenna at the far end. 
> 
> That bundle probably would total to about $100.  (I'm not
> price-sensitive on this matter.  I'm willing to spend money to avoid
> hardware hassle.)
> 
> I remember there being considerable dissention and flamage about
> Atheros, a proprietary HAL that includes excessively large amounts of
> functions that are not required to be obscured by FCC regulatory law, a
> reverse-enginnered open source driver or two, lawsuit threats, and a
> BSD v. Linux licence-modification scandal.  I didn't follow this
> closely, but the screaming could be heard from a distance.

The conclusion was that the FCC indeed required the obscuration at the
time. However, a more recent FCC ruling seems to have rendered that moot:
http://www.linuxdevices.com/news/NS9075126639.html

> Once again, in no way am I suggesting I pick only from the
> above-described parts.  They're merely the first hard data I have on the
> problem.
> 
> (One of the advantages of the Bay Area Wireless User Group of blessed
> memory was that it was a treasure-trove of information about connector
> gotchas, antennae, and the comings and goings of commercial bundles.)

If you were to buy today, and you wanted to avoid any binary-only code,
this would be your only real option:
http://www.sparklan.com/product_details.php?prod_id=170
100% pure GPL