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is there a miniPCI card available containing this chipset that I can plug into a little router board?

Not having read the article (this is Slashdot, of course) I don't know exactly what chipset(s) this is for, but this might help...

Just curious,

If you have compatible wlan hardware like Atheros, would it be possible to configure a mesh network on them? Or do you need special 11s compatible hardware?

I know the OLPC has specialized hardware for this.

Not all hardware is supported by all operating systems. Get used to it. I recently retired a Windows 2000 Pro installation. The biggest reason was ****Hardware Support****. I travel and do Power Point presentations and support others that do the same. As such often a presenter will have his presentation on a USB flash drive. Just for fun, take any modern collection of USB flash drives and plug them into a Windows 2000 laptop.. The endless search for an internet connection on the road to download drivers finally got to me. I Installed Dapper Drake and have been very happy since.

Do a little research and find a supported WiFi card. Most Intel cards are supported out of the box now so your Centrino Laptop should just work.
http://www.intel.com/support/chipsets/sb/CS-022095.htm

Many adaptors bought at Best Buy does work on Ubuntu just fine. Check your chipset first. The only way to get support for the Linux holdouts is make it a support, return and market share issue for them. If you have an incompatible card, call the company and ask for drivers. If they don't have drivers, ask for a refund. They will get the picture if it becomes a big enough issue for them.

By the way, I have an older Thinkpad T21 which doesn't have built in wireless. I use a D-link Air-Express PCMCIA card with a supported chipset. It works fine.

http://www.atheros.com/news/linux.html

Think about what you are saying... I would rather use a $200 OS instead of buying a $40 card to use a free OS. I fail to see the logic unless you just happened to already have a $200 OS just sitting unused someplace.

In the case of my laptop, it was buy something to replace Windows 2000, or buy a compatible card. Since the laptop didn't come with a card, I would need to buy one regardless. I just made sure it was Linux compatible when I bought it.

http://www.etheros.com/news/DLink2.html
http://madwifi.org/wiki/Compatibility

By some strange fate, the laptop I bought two years ago (Toshiba Satellite A70) happened to take Ubuntu Linux right away without any problems. Almost every installation of Ubuntu I did later had more problems. One installation had a problem with intel integrated graphics, which after a few hours of searching I fixed by changing some memory setting in the BIOS.

Another computer had problems because of the wireless card. My laptop worked so well because it had an Atheros card (example of open source driver).

Bottom line is: I would not buy Atheros-based cards, and rather go for RaLink or ZyDas.

Certainly, Ralink, Realtek, Atmel (to some degree) and ZyDAS (no longer a company of its own) are the good guys among wireless chip manufacturers.

In order to be able to vote with one's wallet (or credit card), one needs to get to know who are the good guys among device manufacturers as well (namely which chips are inside the various wireless devices).

Here are some links to support these decisions:

Devices using Ralink chipsets
http://ralink.rapla.net/

Devices using Realtek chipsets
http://realtek.rapla.net/

Devices using ZyDAS chipsets (mostly external "stick type" USB devices)
http://zydas.rapla.net/

Beware of those manufacturers who routinely change chipsets without changing a device's name or model number!

Btw.: It might be worth noting that ZyDAS has been acquired by Atheros earlier this year. The open ZyDAS drivers are still available. They have been moved (e.g. for the popular ZD1211B chipset) to

http://www.atheros.com/RD/ZyDAS/web_driver/ZD1211B /

Regards,

Walter.

Actually the presence of 802.11b devices on a 802.11g network will slow the network down, just not all the way to b speed. See this table for example. As stated there, you seem to drop about a third of the speed, and noting the source [PDF], I'd assume that data is reliable.

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.

The Atheros based cards are great. D-Link sells a DWL-G650 PCMCIA card and a DWL-G520 PCI card, both using Atheros chipsets, for around $45 ($30-35 on sale usually). The Madwifi project supports these at http://madwifi.sf.net/, and the driver supports the use of wpa_supplicant for WPA.

I use these cards myself and have recommended them to many people, and almost all of them are happy with the results. (The one that isn't apparently got a bad card and is too lazy to exchange it.)

The other thing that helps here is the fact that D-Link doesn't change chipsets in the middle of a product line like other crappy brands (at least, not in _this_ line).

If you're biased against D-Link for some reason, Atheros also has a great list of manufacturers/products that use their chipsets - this is something every chipset manufacturer should have on their page.

How many people have ever looked at sourcecode released by vendor? Even better - how many has SEEN any contributions released by vendor that have any significant impact?

Has Realtek ever released source for their wireless driver (for 8181, for example)? Nope. Has Broadcom ever released source for their wireless driver? Nope again.

You want to use Atheros in your AP? Fine. All companies, so far, either cash out $20,000 and get the sourcecode from Atheros, or they subcontract the job (to someone from http://www.atheros.com/partners/AADC.html list). No GPL here.

Not to mention that many Atheros based APs are running VxWorks, not Linux.

Who cares if vendor released a patch that changes some allocation routines (specific for hardware platform their AP runs on) or whatever.

Vendors only care to rollout product ASAP. Nothing else. Most of the time, they roll it out even before it's actually production ready ("we'll fix the bugs as we go" approach).

If FreeBSD allows them to rollout products faster - they'll go with FreeBSD. But something tells me (and it's not part of *BSD vs Linux argument) that they'll stick with Linux, since there are countless wireless-ready development kits/boards available.

Don't think they'll take another route, just because of BSD license.

So you're saying that Intel and Atheros are breaking the law?

Let's try not to lose sight of the fact that Linux has many times the hardware support of Windows.

Linux has many times the architecture support, not "hardware support". Sure, just about anything with a floating point unit (and even a lot without) can be made to run Linux. But that's not what we're talking about. I can't think of a single hardware device that will work with Linux but not Windows (though I'm sure some exist). I can easily think of countless devices that work with Windows but not Linux. In fact, I have to be careful to check compatibility of devices I'm interested in so I don't get an unpleasant surprise later.

Ever try running Windows on an Alpha? What about MIPS?

Personally I've run Windows on Alpha (an old NT server), MIPS (a P/PC and H/PC device) and ARM processors (my PPC2002 Jornada). The SHx family is also supported. Perhaps you're just not familiar with the full line of Windows products.

I would argue that Centrino is a commercial brand introduced by Intel to:
a) improve Intel wireless capabilities in their laptops
b) sell more notebooks
c) confuse customers
d) let me to write this comment on Slashot :-)
Choose your option.

Check atheros paper about this topic: Centrino vs Pentium or this other page En qué consiste exactamente la tecnología Centrino?

Actually 11g/11a theoretical max tcp-delivered bandwidth is 30 Mbps, once you add "interference, equipment quality and distance", it drops further. i get about 23 megabits/s at the office delivered to wget with 11a. Atheros has a nice paper with a table with these figures on p. 2.

Atheros' CEO is a perl hacker, so I guess that this would mean that whatever they do, it will be good, no?

-5.4GHz experiences more attenuation, so less range

Take a look at this. You can check my previous post to here to see a more detailed explanation. It seems that the range is equivalent with 802.11b and close to that of 802.11g.

While looking into the differences of 802.11 a|b|g I found this article over at tom's hardware. It appears that the second generation 802.11a protocol devices now have much better range than the previous first generation 802.11a devices. This can also be seen by a recent whitepaper by Atheros (The company whose chipset is used in most widely available wireless devices from such companies as Netgear, Linksys, and D-link). With better bandwidth performance than most 802.11 b|g devices on the market and equivalent range to b|g devices, all while operating in the 5 ghz range, perhaps 802.11a will make some what of a comeback. The potential really comes from the fact that right now you can buy wireless APs now from Linksys (WAP55AG) and D-Link(DWL-7000AP) and wireless cards from linksys,netgear,and d-link that do all 3 protocols. I know that right now I will be looking at running my AP in 802.11a mode and not worrying about interference coming from the 2.4ghz range.

802.11b/g:

If you have a Linksys 802.11 b/g router (WRT54G), then you have boughten a piece of crap. No seriously, that router has terrible range. I should know, I used to have one. I verified on the net, that is was the case. I exchanged it for a Netgear WGR614, which uses an Intersil PrismGT chipset, and my coworker bought the DLink variety, which also uses the Intersil PrismGT chipset. It gets MUCH MUCH better range.

With an Intel 802.11b gateway that I used to have, I would get -65db signal in my master bedroom, and XP would report VeryGood connection. With the Linksys G router, I got -77db, and XP reported Poor signal connection. When I connected the Netgear G router, I got -57db and XP reported Excellent signal strength. I borrowed a friends signal booster, and connected it to the linksys, and found it to be useless.

I ran NetIQ and did some through-put tests. With the Linksys, I got 17mbit/sec when I was in mixed mode, and 20mbit/sec in G only. On the netgear, I always got 21mbit/sec. With the 802.11b, I got 4.5mbit/sec...

802.11a:

With an AP based on the Atheros 5000 chipset, I got crappy signal at our work. Thanks to Tomshardware, I bought a Netgear WAB102, which is the ONLY A/B dualband AP that uses the second generation A, (Atheros 5001) chipset. This thing is awesome. At our work, its coverage actually exceeds that of B.

At home, I get -59 to -65db in the master bedroom on A. However, the cool thing is the throughput. In non-turbo mode, I get a constant 24mbit/sec in the master bedroom. On the G router, it seemed to be more sensitive to the signal strength, as it would always connect at 36mbit/sec or 48mbit/sec, consequently, I only get 21mbit/sec throughput if I was in the computer room. In my bedroom I got between 14-18mbit/sec.

With A however, I got 24. And I enabled Turbo mode, and it connected at 108mbit/sec, and I measured a constant 35-40mbit/sec everywhere in the house! and thats a two story house, with the AP upstairs.

Keep in mind the "b" radio in the Netgear WAB102 is a piece of crap Atmel chipset. Everytime I "accidently" rest my arm on my card, I lose connectivity. I found my Prism2/Prism3 cards would go into 1mbit/sec mode, and never recover, unless I unplug the card, and plug it back in. The A radio in it on the otherhand is truly awesome.

In the end, I returned my G router, and kept the Netgear WAB102 dual band A/B, and reconnected my Intel gateway for the B, and use Netgear for A.

Atheros has an white paper they posted talking about range and such of A and B, and testing results in an actual home environment and corp environment. Its rather interesting. I verified it myself at our office here with my own testing with various A and B equipment along with Netstumbler and NetIQ, and it is truly suprising.

So anyways, most range problems can be attributed to a shoddy AP, not the "technology". I mean, I've tested the Netgear WAB102, Netgear WGR614, Linksys WRT54G, Linksys WAP54G, Intel ProWireless 5000AP, Intel Gateway, DLink DI-624, and the Linksys BEFW11S4. I tested with Orinoco Silver, Linksys WPC11V3, Linksys WPC54G, Linksys WPC55AG(my fav card), Cisco Aironet 350, Linksys WUSB11 v2.6, and assorted generic Prism2 cards, so I can safely say I know what I'm talking about ;)

(I work in a lab and have lots of wireless toys, if you guys can't tell :)

Using its proprietary extensions, Atheros is claiming to deliver up to 90Mbps of real-world throughput (with a raw data rate of 108Mbps).

I agree that 802.11b as it is today is not an alternative to GPRS or CDMA, but here we have Atheros claiming to have a solution for 802.11a that has up to five times the range of 802.11b without violating power restrictions. The technology this is based on was called 802.11h for awhile.
Besides, while flat out range is the easy way to compare cellular and WiFi if you're arguing from the former's perspective, it misses a key difference in the technologies that we see embodied within a mess of 802 standards: Quality of Service and Security. These latter points may be more dangerous for old school wireless providers than simple range comparisons. In 802.11e, we see Quality of Service being laid out for wireless LANs. Once you start adding QoS and 50Mbps bandwidth together with a technology that is inherently mobile the definition of LAN starts to get a bit arbitrary and leaks into MAN or WAN.
However, you might counter that even if QoS on ad hoc wireless networks was being handled with the kind of efficiency that's currently only found on backbone switches it still couldn't become some kind of giant mesh network. Why not? Well the answer is trust. Folks aren't going to share a piece of their connection even if it means lower prices for everyone. They just don't trust each other, right? Hmm. Well sometimes that's true, but it all depends on the details.
Enter the Dragon --no, wait it's just 802.11i and 802.1x but close enough. These bad puppies are about taking the need for trust out of the picture by securing up these protocols.
Fantasy! Rubbish! It's all lies! I hear the cynics amongst you. But you have to admit if these standards bodies have already been formed at the IEEE, then somebody is taking this seriously.
Sure, for now GPRS and CDMA --the cell phone sustems-- are the way to go for the tiny minority who would pay that much for wireless data services. But personally I think wireless devices will take off about the time they become cheap enough that you can stream MP3s off your home server and that will have to be very very cheap probably like $10 a month for all you can eat 256K streaming downloads and I believe 802.11 standards will make it happen and the user's devices themselves will be the access points. If you think it sounds far fetched, tell it to the IEEE. And, get that resume updated!

802.11a supports the much higher speed, but at a price of greatly reduced range

From what I've read (pdf warning) 802.11a has similar range to 802.11b and for a given range 802.11a will operate at a higher speed than 802.11b. 802.11a does have a shorter range at which it will operate at it's maximum speed, but even when it falls back it is faster than 802.11b.

FWIW, Atheros claims that 802.11a works up to 225 feet and provides more bandwidth than 802.11b at any range. Take it with a grain of salt since Atheros makes 802.11a chips, but it's still worth a read.

1 megabyte pdf on the range of 802.11a This pdf talks about the range of 802.11a and how they tested it, and it also includes some cool charts comparing it to 802.11b. It turns out the farther your computer is away from the base station the slower the connection is.

Perhaps the Proxim press release is a bit unclear on the range issue. The 802.11a products can step down to several lower speeds to tradeoff range versus bandwidth. The result is comparable range to 802.11b, but higher bandwidth.

There's a good paper discussing this issue in technical detail here.

(The Proxim product, as mentioned in the press release, is based on the Atheros chipset).

Second, 802.11a has more channels available than 802.11b. That means that there's less chance that nearby networks (at your neighbor's house, for example) will interfere with your network (when nearby networks use the same channel, each sees reduced bandwidth).

At 5GHz, walls attentuate the signal even more than at 2.4GHz, the 802.11b standard, so it remains to be seen how close you will get to the 54MBs signalling rate. With the MAC protocol overhead, even in the best enviroment, you'll loose between 30-50%. This is not just a wireless feature, 100 MBs Ethernet also gets a MAC penalty, just not as much as wireless.

What will really impress the geek in all of us is a new wireless products utilizing Ultra Wide Band (UWB) techniques. A UWB radio tranmits its signal using gaussian monocycles instead of sine waves. With ultra-low power emmisions and over 2GHz of spectrum, conventional narrow-band systems are not disturbed and UWB signals appear as white noise making UWB very hard to detect. Highspeed bandwith, precise precision and location, and RADAR capabilities are being demonstrated today. A leader in the field is Time Domain. The FCC is expected to rule on legalizing UWB this fall.