Please create an account to participate in the Slashdot moderation system


Forgot your password?
The Internet

Wireless LANs and Linux 156

Patrick Mullen writes "Wireless LAN products are hitting everywhere these days. I've just an overview of these technologies, the products out there, and how they look on Linux." I'm a huge fan of the wireless stuff (we've been doing wireless lans for years now... if only we had wireless electricity ;) And check out Absolute Value Software: Mark's working on a simple router/gateway (that runs Linux) and looks extremely promising.
This discussion has been archived. No new comments can be posted.

Wireless LANs and Linux

Comments Filter:
  • by ckd ( 72611 ) on Wednesday October 18, 2000 @05:50AM (#696822) Homepage

    802.11, with the boost of Apple's AirPort, has started really taking off (pun intended). USENIX conferences have had Wavelan or Aironet (now Cisco) gear available for a couple years now, and it's wildly popular; now, Aerzone (which used to be Laptop Lane) [] has partnered with Delta, and they are starting to offer 802.11 service in airports (the ones with airplanes, not the plastic flying saucers). I think American has a deal with another company, but I can't remember the name of that one.

    The nice thing, of course, is that since it's wireless, you don't necessarily need to be in the lounge to get a signal; so next time you're in the vicinity of a Crown Room or Admiral's Club, see if you have any signal.

    For that matter, just see if you see any wireless LANs around home! When we set ours up, it turned out that a couple companies across the street showed up in the choice of networks pop-up menu....

  • The 2.4ghz band is available in most countries around the world. Two exception, until recently, were France and Japan, but both have agreed to clear the band (I think it was the military in France that was on it).
  • One of the things that is a real stumbling block is that many of the drivers don't work properly or at all on an SMP machine. If you are like me and have a dual CPU box, wireless networking is very problematical. Another thing to watch out for is that while the Lucent drivers work fine in PCMIA mode, they fail if you try to use a Lucent card in the PCI slot adapter they sell.

  • Note also that once you modify it, it's not a Part-15 device any longer and you should have a license.

    That's odd: according to the Lucent site (and my Lucent reps) there's no regulation of these antennas. I ran a couple of directional (Yagi) antennas for a 802.11b p2p link test and I asked about FCC requirements.

    Hell, they even list the 24 dBi Parabolic Grid as available for 'FCC and unregulated countries only', which leads me to assume they're FCC-legal..

    (check out their product site [].. Very cool..)

    Your Working Boy,
  • Mobilestar, that's the name I was trying to remember. I had also forgotten about Wayport; thanks for noting them.

    I guess that proves my original point even more, though; 3 companies working on the market for airport 802.11 connectivity means that deployment should be very quick once they all get going.

  • There is a Linux distribution called FlyingLinux.NET [] used at the Royal Institute of Technology in Sweden that is claimed to be the first linux distribution oriented to mobility services. I used it last spring on HP OmniBooks with Lucent WaveLAN cards.
  • Think about it. Batteries still have to be connected to the device they are powering via wires. A battery is simply a portable power source. Just like a generator or a solar cell, it still has to be connected to the device being powered via wires.

    Tesla was cool.
  • I have Lucent's Orinoco Gold working under Linux 2.2.17, uses the wvlan module. it's also 11Mb/s speed now, with a 10/100 base station.

    I am also making it availible on my network for the more mobile users - who typically want to be running about having meetings while still connected.

    now, if my portable's screen wasn't hooped...

    generally, it seems great, just a shame that there seem to be so few snmp products kicking about under linux... (if you know some good ones, pls let me know!)

    I am now waiting to get my hands onto an ipac handheld - and have gnu/icq all over the offic

  • I'm a big fan of the Apple Airport Base Station. []

    Sure, it looks like an iMac turd, but it's a slick little device that not only provides wireless bridging to the wired network, but also automatically does network address translation for the wireless devices. It will even offer DHCP / NAT for the wired machines, and manage your dialup for you (it has an integrated 56k modem).

    So, on DSL/Cable setups that share a single IP, it frees up whatver machine was forced to do IPmasq. And over a shared dialup, you no longer have to have anybody running diald.

    It only costs $300, which isn't that much more than what you'd pay for a small home router anyway, and of course it also gives you wireless access (compatible with 802.11b products []). I get excellent reception throughout my entire 3-story house, including the basement.

    Best of all, you don't have to have a Mac (or Windows) to use it... there's a java-based configurator [].

  • Certainly, I ran it that way for most of last year.

    But, frankly, using a Linux box as the gateway system for these things is more difficult to administer and not much cheaper (if at all) than using dedicated hardware. When a wireless bridge and NAT router (such as the Lucent Orinoco RG-1000 or the Apple Airport hub) costs under $300 they're a great deal.

    My wireless system, which started out using WLAN on a Linux system that was also doing IP masquerading for my cable modem, eventually migrated to the Orinoco AccessPoint II for range and ease-of-administration improvements. (I also retired the box for IP masquerading when hardware NAT boxes dropped well under $200; now it's just a server.)

    Let me tell you, wireless rocks for basic net usage. Performance, while well below 100baseT, is more than good enough for two laptops running simultaneous full-bandwidth RealVideo feeds. For home use it's hard to complain about that.

    My company rolled it out to all laptop users last year, too, so I've seen how it scales -- and the answer is "pretty darn well." Bulk downloads are fairly slow, but day-to-day use is indistinguishable from the wired connection.

    Wireless will change your usage pattern.

    jim frost
  • Ya know, lately I have been having these feelings of uncertainty about the potential health effects of the radiation our bodies are forced to absorb every day. Back in the 1920's-1930's Television was a dream and radio was, what, 10-100W transmitters? Not much ambient radiation. Flash to now. We have local TV, radio transmitters, cell phones, bluetooth, wireless LANs, Microwave transmitters, and satellite. Not to mention CRT screens, television screens, CB radios.... You get the idea. How is all this affecting us? Are the cancer rates any higher? I know teenagers appear dumber, but that's just observation. Are we going to be forced, some day in the future, to set up RF free zones for sensitive people?

  • I'm not clinko.

    Oh wait.
  • I think the most recent stuff I have seen on this has been using microwaves to transmit waves that are converted to electricity.
  • Wow! Smart thinking. To post something to make it seem as though you, clinko, have no knowledge of any previous posts in this thread by you, clinko.

  • by Xref ( 144610 ) <> on Wednesday October 18, 2000 @05:52AM (#696836)
    There are released, supported Wavelan now ORiNOCO card does have drivers for Linux.

    I quote from the Lucent produce listing:

    "The ORiNOCO PC card is compatible with Windows® 95/98/2000/CE/NT (NDIS Miniport driver), Apple® Mac OS 7.5.2 and higher, Novell Client 3.x & 4.x, and Linux (kernel versions 2.0.x to 2.2.x) for Intel processors."

    Seems quite a bit broader than this article's "Windows 95/98/NT/2000"...
  • CMU's had a wireless network in every building on campus since this summer, and most buildings last year. As a proud user of this wireless system (and Linux) it's great! I can IRC and read /. from class, from the park, and even from the bus stop. We use the Lucent WaveLAN Silver cards, and I had no problem at all setting it up under Linux. And Linux can even restart the network card after I suspend (something the Windows partition can't do)
  • I am running three Lucent WaveLANs in my house, and they do run under Linux, and at 11mbits too. Indeed, they are supported `out of the box' in Redhat 7.0, though you need to get their wireless tools package to configure them.
  • I was thinking about something the other day, it might interest all of you -- make fake wireless nets using the Cybiko [].

    For a bit of explaination, here goes -- the Cybiko is a small 'toy' directed at teenagers -- it has all the usual PDA features, but the most interesting is that it posesses short-rage wireless capabilities.

    It has an SDK, so I had the idea of making an app and some drivers so that you could connet the Cybiko to your serial port and communicate with other people with the same Cybiko setup. THe speed are limited to about 200kb/sec (IIRC) but they're cheap at 129 USD per unit, and multipule units could communicate with each other.

  • My Dell Inspiron 3800 runs close to 4 hours on a charge and that's with the drive running a fair bit.
  • You have to keep in mind that the more nodes you add in a wireless LAN (or any other shared medium LAN), the more contention you get. For doing a cluster, the practical limit would likely be in the neighborhood of 10 machines... Depending of course on what you mean by "cluster".

    As for a cable/dsl router system, you should check out karlbridge software ( [] ). Their software is what is running under the hood of most of the "Access Point" class machines out there.

    The Apple Airport Basestation, which retails for
    about US$300 or so, contains a Lucent WaveLan IEEE silver card (64bit encryption), an ethernet port, and a 56K modem. I have one that I have upgraded to the Lucent WaveLan IEEE gold card (128bit encryption) and it works wonderfully. I had to use some karlbridge windows-based config software to configure it, but it works!

    Beware of one flaw in the Lucent cards if you choose to try to build your own bridge with it. The Lucent cards will *not* send packets with a different MAC address than their own. Hence, bridging does not work with Lucent cards. In order to get bridging to work with a Lucent card, specialized firmware (which is not freely available) has to be downloaded into the card before it is put into bridging mode.
  • Here's a link to the Java Airport Configurator [] for fully configuring and controlling an apple airport from any OS.
  • Just a few corrections on your post.

    802.11 specifies three PHY layers: Direct Sequence (DSSS), Frequency Hopping (FHSS), and Infrared (IR). DSSS and FHSS both run at 1Mbps and 2Mbps (depending on signal strength.) I believe that IR also runs at 2Mbps, but I've never actually seen one. ;-)>

    802.11a is what you call 802.nextgen. It uses an orthogonal frequency domain multiplexing (OFDM) to deliver from 6Mbps to 54Mbps in the 5.0GHz N-UNII frequencies.

    802.11b is High Rate DSSS physical layer (HR/DSSS). It is an extension to DSSS which adds 5.5Mbps and 11Mbps data rates.

    There is no such thing as "802.11b - 11Mb Frequency Hopping". Only DSSS has been extended to 11Mbps.

    Source: IEEE 802.11 Handbook: A Designer's Companion By Bob O'Hara and Al Petrick.
  • Maybe I'm just outdated but I thought CDMA was Sprints baby TDMA is what most other normal companies are using in the US and GSM is what is used in the overseas markets.
  • wireless tech is cool but for now i think that it's just to slow... hopefully soon... :-)
  • Could the towers in to the magnetosphere that you referred to be combined into the tether described in the "Space Elevator" concepts? At the least, the tether cable would help provide power for the elevator car as it travels. Also, a previous story mentioned a satellite that used the energy in the magnetosphere to provide propulsion, perhaps the inverse could be applied with the "Space Elevator"....

  • Even though the wireless LAN stuff puts out non-ionizing radiation, it still can have an effect on your health, just like a cell phone. I would reccommend not holding your Visor with the Bluetooth module up to your ear to listen to a RealAudio stream.

    IPv6, wherefore art thou? My watch needs an IP!

  • With the 4 monitors and 15 open cases in my room I doubt that my testicles would be happy w/ more radiation from em fields :) Has anyone had a patent for lead underwear yet?
  • I've been trying to setup at home with a wireless environment and I've managed to get the Linux side of things working but the damn residential gateway from Lucent won't talk to MediaOne via DHCP. Anyone got any ideas? I've searched in all the usual places (Deja etc) but to no avail. Thanks, Sean
  • A couple sci-fi books I've read have supposed the existence of microwave power transmission (Borders of Infinity by Lois McMaster Bujold, and A Deepness in the Sky by Vernor Vinge). Are there any projects seriously pursuing this?


    " is running Microsoft-IIS/5.0 on Windows 2000"

    So I would doubt that vi was used to create the site.

    Also there are a lot of inconsistencies. I read this and tryed to figure what they mean by it.

    "We have hit 220 000 000+ Impressions in 200 of the World's Best Publications!"

    My thinking is they have hit 220,000,000 eyes with their blurbs in publications. If this were a possible investment I not know what to do. They have a decent product that could be the next pokemon. But they do not deliver a consistent message with their website most all of the marketing I have seen out of this company leads me to believe they lack leadership and dirrection.

    So while I wouldn't concure with you in your statement of them being phonies. I would agree that they are somewhat misguided in their persuits.
  • What's so special about Wireless LAN's as opposed to normal (Wirefull?) LAN's?

    Seen from the computer's side, it's just a network card, isn't it?

  • I help set up a friends wireless LAN in his house and it was awesome. I was truly expecting wireless to be buggy and slow but I was blown away by the speed and the efficiency. We walked all through his house(which was quite big) and didn't notice any loss in performance. Once I get some money I plan to set one up myself.
  • CDMA was actually invented by Qualcomm. It is used in the US by Sprint PCS (among others). GSM actually uses TDMA as it's air interface, but has different protocols than the other (I forget the standards number) type of TDMA used in the US by AT&T Wireless (among others).
  • by nharmon ( 97591 ) on Wednesday October 18, 2000 @05:36AM (#696855)

    Wireless Electricity [] has been around, in theory, or a while.

    Of course, Nikola Tesla was way before his time.

  • "What's so special about Wireless LAN's as opposed to normal (Wirefull?) LAN's?

    I would guess the lack of wires?

  • Gosh, for a savings of a few dollars, I can have 1/10th the speed, *AND* it only works on Windows and Mac?

    Sign me up!!!

  • My understanding is the Cybiko has a very restrictive policy regarding use of its SDK. Pretty much everything you do becomes their property, to be marketed through them. *Not* open source, by any means.
  • Fun sci-fi type idea.

    It could possibly work if the whole concept is valid (still no proof) and the space elevator idea is valid and built. Lots of ifs. ;)

    The solar wind drive you mention wouldn't work for this. It creates it's own magnetosphere and uses it as a solar sail. Thus it expends energy, rather than generating it.
  • Bluetooth (aka 802.15) makes it necessary to define the "PAN," or Personal Area Network. (No, I don't think that's just marketing hype.) It basically means considering all the cords coming out of your computer as a small network. So now all the local devices--phone (cell or home), computer, PDA, webpad, external drives, printer, scanner, FUFME--all know about each other and can all do what each does best without any of the others having to duplicate that functionality.

    When they need a larger connection--computer in the next room, printer down the hall, baby monitor--you move up to a LAN. The LAN can be wireless using 802.11.

    When the LAN needs a wider connection--email, web, games, new pr0n scripts for the FUFME--you move out a WAN which is usually the Internet at large. The WAN could be wireless through fixed wireless (RF), satellite, optics, etc.

  • Hey you need wireless electricity to run a LAN ?

    Then you need "Electricity over IP": plamps-00.txt

    so long
  • i don't think you get it.. the topic is wireless.. the point of wireless networks has really not much to do at all with a ethernet card in the back of your computer connect to the network by a cat5 cable it has to do with having a wireless pcmcia card in your laptop and having a WIRELESS connection to your network or the internet. comparing the prices between buying a cheap 10mb ethernet card for your desktop and buying a wireless pcmcia card for your laptop is worthless bantha fodder...
  • Good for you. I'm sure no one who reads here has ever even heard of the linksys product... Who are you kidding - ipmasquarding all the way.
  • As wireless networking has come into it's own in the last year or two, a small number of pioneering ISP's have begun offering wireless access for home and corporate users. Perhaps I can score a shameless plug for a friend of mine, and give those of you experimenting with wirless a valuable resource to exchange information.

    My friend Jack Brewer, owner of MicroVillage Internet in South Bend, IN created their SkyBurst wireless access service a little over a year ago. The service offers internet access to both residential and commercial customers. The technology presently allows throughput from 11-22mbit over a cellular style of overlapping coverage areas via (presently) 19 radio towers covering the Michiana area. At the heart of the operation exists a large number of linux routers.

    Presumably, this Slashdot article was dealing with the more pedestrian 2.4 GHz consumer wireless technology for small home LAN's; However many of the wireless adapater manufacturers at the client end offer hardware that overlaps both applications.

    If you are an ISP operator or network administrator interested in wireless WAN technology, or are already in the field and want to brainshare, you may wish to visit for more information.


  • Cisco's Aironet wireless products, (they bought aironet recently), are pretty bad-ass. Suckers seem to work REAL well, and they support 11Mbps wireless LAN rates. BreezeCOM and Lucent make pretty good wireless gear as well.
  • If you plug the wavelan-provided antenna in to a wavelan card, and you modify neither the antenna and its cable nor the card, it's a Part 15 device. If you open it up and do your own thing, it's not a Part 15 device any longer.

    Note that the 14 dB antenna isn't an omni. You don't get 14 dB from an onmi. Gain is at the expense of concentrating the energy in one direction or at least one plane.


  • $800-1000? Even assuming that HomeRF equipment is free, you'd need a pretty big network to have that much of a price difference considering that 802.11 base stations are only $300 and cards are only $100.
  • by Ethelred Unraed ( 32954 ) on Wednesday October 18, 2000 @06:00AM (#696868) Journal
    Stupid question, perhaps, but why on Earth isn't Airport [] mentioned in the article? After all, it's Linux-compatible (at least I remember seeing some drivers for it in recent linux-pmac kernels) as well as Mac-compatible, easy to install, configure, etc. etc. etc.



  • It's called a 'battery.' Apparently they've been around for quite a while now.
  • > The problem was, Westinghouse dropped his
    > support of it because it became difficult to
    > charge people for it.

    I supose we should be glad though. Between the health risks of that much electromagnetic radiation, and the fact that tesla coils have the annoying habbit of proving that ground isn't an infinite energy sink (even back then one end of the AC generator was grounded - Tesla sent so much energy into ground once that it burnt out and the generators at the power plant and set them on fire)

    I do have to wonder how modern electronics would have evolved in such a world though. Circuits would be way different - they would have to be to survive.

  • 1. Extreme expense (hey most people even if they are made out of money find it at least slightly disquiting to see triple digit cell phone bills every month).

    2. No pressing need for wireless devices (why do you think they are trying to persuade people that a stupid little dumbed down presentation of a homepage (it makes lynx look extremely complex) is the real thing? they are getting desperate). I can do everything with patience and a regular line.

    3. wireless internet access is extremely expensive even more than phone access and wireless broadband is like giving away your first born or one of your limbs.

    4. Lack of infrastructure. I still cannot use my connectivity anywhere in the world at all. With regular telephone networks at least I have the (costly) option to say dial into my ISP from Mongolia and surf the web.
  • by Ethelred Unraed ( 32954 ) on Wednesday October 18, 2000 @06:04AM (#696872) Journal
    I did some double-checking, and yes, Airport works with Linux/PPC -- Benjamin Herrenschmidt ported the WaveLAN driver [] and got it to work with the Apple Airport cards.



  • Since beginning my postings on Slashdot I have become increasingly alarmed at the number of idiotic morons that say the most alarming, or the most uninformed things. Case in point, the above first post.

    First posting is a priviledge lad. You should not go out of your way to get the first post and then waste it on something as stupid as 'boom'. You should in fact use the great opportunity to have your views known. Dare I say, even about the topic at hand? Yes, it is possible to have a first post that contains a little bit of meaning. I would even prefer a Penis Bird Guy post to this idiotic AC's retarded attempt to get attention.

    Now, why does this bother me? On its own it probably wouldn't. But combine this with the fact that in every article the stupidity of the posters is only overshadowed by the obvious stupidity of the moderators and you start to understand why I am quickly losing faith in humanity. I realize that the audience (and hence the moderators) here is made up of mostly young adults and teenagers. However, if this is the youth of America in action, I can only doubt our survival in the future. Such blatant stupidity and obvious power tripping arrogance should not be tolerated or fostered. But here, not only is it tolerated, it is encouraged. Moderators are told to abuse by the 'majority rules' crowd. Don't let an opinion you disagree with get moderated up. No matter how eloquently written that opinion is. No matter how many facts the poster used to back his position. No matter how right he/she is or could be, don't let that opposing view be heard! It is strange to me that a forum based on freedom is in actuality just a place to reinforce the stupidity that has been bred into this generation. If the youth of America is represented here on Slashdot, then I don't just weep for the future, I bleed my wrists in pain and indignation at the prospects that lie ahead for us.

    As Slashdot continues to attempt to drain out your indignation, please do not be afraid of having your own opinion. As Slashdot goes out of its way to indoctrinate our youth into the 'majority' mindset, as slashdot attempts in every way to completely obliterate our ability to think for ourselves, stand up for your rights. Do not be afraid to continue expressing your opinions. No matter how unpopular those opinions are, you are our hope for the future. Please remember that.

    I realize this will get moderated down into oblivion quicker than any other post on the forum, but please, if you read it, remember it. Do not be afraid of your thoughts. Do not let the slashdot hordes convince you that you must wipe your mind clean of 'unpure' thoughts. Remember your mind. Remember your youth. Remember your own thoughts. And most importantly, remember to be different.

    Do not be afraid of your differences with others. Embrace them! Hold onto those differences as if your life depended on it. It may be rough trying to ride through your youth this way (and I know, because I did just that), but it is worth it. As I quickly approach thirty years of age (27 and counting) I realize that I was never afraid of all the bible thumping morons that were always so 'concerned' about my differences. In fact, I usually just laughed it off when it didn't piss me off. And now, I still play that evil, 'satanic' heavy metal music. I still enjoy a good 'evil and satanic' Dungeons and Dragons game. I still enjoy a good horror story or movie. And I still play those damnable, corrupting violent video games. I still wear black tee-shirts (the ones that got me called a satanist on a daily basis by my 'peers' as a youth). And nobody is ever gonna pry that guitar out of my hands (not even my wife, but she wouldn't try).

    You can do it. You can make it through your youth without becoming the zombie that the 'popular' crowd wants you to be. You don't have to be popular. You just need to be 'YOU'. And believe it or not, Slashdot is totally against the entire concept of being YOU. Slashdot is all about being a part of the 'in' crowd. Slashdot is all about being 'hip', or 'kewl' or '3l33t'. Please, even if you are naturally 3l33t (and some are), do not succumb to the urge that Slashdot places in front of you. Do not give up your differences. Allow yourself free thought. Allow yourself to voice your opinion. Allow yourself to live, as you and you alone.

    Slashdot will not succeed in destroying the free-thinking minds of the individuals that make up the youth of America. Don't let it succeed. As it appears more and more to just be a 'anti-corporate' corporation in and of itself, go against the grain. Do not be afraid. The future is yours, but only if you are willing to remain you.

    Yes I'm feeling philosophical today. Is that a reason to mod me down? Probably. After all, I dare to accuse Slashdot of something that isn't cool. How unpopular of me! Fuck popularity. I'd rather be able to look myself in the mirror than be a druken, drugged-up, ass-kissing, 'thank you sir may I have another' moron like the great Slashdot 'community'.

    Be different. Be yourself. Don't be, 'one of them'.
  • Is this going to be like the "paperless workplace" they promised us? Will we just get more wires (in form of hubs, wiring our houses so devices work all over, ect) as wireless becomes more prevolent?


    Cognosco: (Latin) To examine, enquire, learn
  • Serendipity. This discussion appeared on Slashdot just hours after I'd finished writing this document [], which describes how you can use a Unix (including Linux) computer as a 802.11 wireless base station.
  • I've been looking quite a bit at the linux-wlan code which you can get from the Absolute Value systems page. Frankly, it's bloated beyond belief and in some places just plain broken (e.g. a jiffies based timeout with interrupts disabled). It has very much the look of code produced by someone being paid by the line. I'd rate its chances of getting into the standard kernel in anything like its present form as virtually nil.
  • That story URL was good, here's another (and I think more comprehensive), from a DC LUG meeting more than a year ago.

    Thanks to Peter Teuben for doing this: ben /linux/wireless.html []

    - Serge Wroclawski
  • by Froggie ( 1154 ) on Wednesday October 18, 2000 @06:16AM (#696887)
    It's nice to see an article on wireless networking, but this one's a bit too trivialised. It misses information and there are a few errors:
    1. Lucent cards are 11MB
    2. Lucent cards have Linux support, both directly from Lucent (binary module) and as 3rd party (pcmcia-cs).
    3. Samsung's Linux support is 3rd party.
    They also don't mention a number of other cards (3Com have a Linux-compatible one, Compaq have a Samsung-compatible one, Elsa do one, there's the cheapo non-interoperable 2Mbit ones I've forgotten the name of, and of course there's the Apple stuff), so don't take this as a complete list by any means. Nor do they mention that the linux-wlan project is only interested in a limited number of cards. Finally, they say nothing about 802.11b base stations, which (in my experience) cause the most confusion to people when they're buying wireless stuff.
    Finally, mobile IP isn't really related to wireless networks - it's a means of allowing your machine to move around a network topology, rather than a building. It's not necessary to understand or to have a mobile IP system to use wireless network cards.
  • Well - to start:

    Bluetooth is one international standard. It works very well at VERY short range. It is not going to be a good setup for LANs - poor security, too slow, too unresponsive to change - but blows everything else away when it comes to phone earpieces, or scanner to portable printer connectivity. It also kills 802.11 devices in close proximity to it as its hop speed is so high.

    802.11 is also international, and considerably better for a home LAN

    802.11 - 2Mb Frequency Hopping - pretty solid, with good range. Not bad for industrial settings where end users have a telnet/3270/5250 application.

    802.11b - 11Mb Direct Sequence - very solid, and very secure; signal can be at a lower level than rf interference, so can't be seen. Signal only appears when decoder with identical chipping set is used. I've had Quake 2 over a 5 mile link with directional antennas - no judder!

    802.11b - 11Mb Frequency Hopping - An excellent choice for the home. Frequency hoppers are much cheaper than DS transmitters, and 11Mb gives much better throughput than 10BaseT (CSMA/CA overhead is less than half CSMA/CD)

    802.nextgen - 25Mb radio, at 5GHz. Throughput - yummy, range - down a bit, unfortunately.

    Cat 5 my house? No need with RF!!!

  • You know a way to make 802.11b work as a LAN (ie, not just peer-to-peer) without an access point? Do tell.

    Routing is a basic concept of TCP/IP networking. If you are so unfamiliar with it that you don't even know it exists, I would recommend you start here:

    TCP/IP for Dummies, Fourth Edition []

  • The software that comes with it is Mac-only, but there is a Java application on the net that manages it. The management protocol is SNMP, so a native Linux application to manage it would be easy enough.

    IIRC the card inside is WaveLAN, so you might be able to use the Lucent WaveLAN tools on it.. Also, I've heard if you are interested in cracking the case you can stick a nice 14dB amplified omni antenna on it and get mega range.. I'm thinking of doing that to mine so I can get data out on the porch ;)

    Apple really nailed it on that one. No PC vendor comes close, and a comparable base station from Lucent or Cisco costs waay more..

    Your Working Boy,
  • by peter303 ( 12292 ) on Wednesday October 18, 2000 @07:18AM (#696895)
    Via microwaves.
    People have proposed oribiting solar collectors and microwaving it back to Earth or Luna.
    Some problems:
    -Any moisture in the atmosphere screws the method,
    but that still leaves several deserts with 99% downlink.
    -Beams spread out. Masers, solitons, etc. may get around this problem.
    -Anything near the beam may get fried.
  • In 1993, before the collapse of Communism in the USSR, but in they heyday of Glasnost and Perestroika, I went on a school exchange trip to Minsk. One of our daytrips was to Minsk University, where we were shown a lab, and it was explained to us in halting English, that they were researching the "transmission of electricity without wires".

    The room was dominated by two enormous steel balls, and every second a spark passed between them with a deafening "click". We recieved no further explanation.

    All true.

    What's the point of this story? Um... I like stories.
  • The funny thing is you think you're telling me exactly the opposite of what I think, but in fact, you are agreeing with me.

    By 'being different' I certainly didn't mean to be different in whatever is the most freakish way you can be. I'm different from anyone else I know. I play heavy metal guitar, yet I don't drink, don't smoke, don't do drugs, don't have tatoos, don't have peircings or any of the other things that are 'supposed' to go with it.

    You have, in fact, embraced your differences. It's just that you are so comfortable with your differences that you don't even think of them as differences. That's a very healthy way to see things.

    Embracing your differences isn't about 'standing out'. It's about being who you are. You don't need to be a freak to be different. Sometimes normalcy is different. It certainly is in this day and age.
  • Well, that would be a savings of nearly $800-1000 (when you included 802.11b's access point and LAN cards together) and HomeRF now matches 802.11b's 11mbs. And what makes you think that either HomeRF and Bluetooth will only be Windows/Mac? My understanding is that Linux plans are in the works for both.
  • For good Linux info, you should check out Jean Tourrilhes' Wireless LAN HOWTO []. It's got a good overview of the technology, the standards, the cards, and the Linux drivers.

    Lately, there have been a couple of 802.11b cards come out that are pretty cheap - check out the Linksys WPC11 [] , which can be found for around $120 a pop [] (if you can find it in stock...) and also Addtron []'s AWP100 card - no info on their site, but they told me it has the PrismII chipset, which is what the AbsoVal guys are working on, I believe. It, too, is around $120 [].


  • This article does not do a good job of talking about what products are available, or comparing them.

    For one, Lucent WaveLAN cards run at 11Mbps, not 2 as the article states. In addition, Lucent provides binary x86 Linux drivers on their web site.

    For another, it's not really important whether or not the card's vendors provide Linux drivers. What's most important is whether or not they work under Linux. The fact is most of these cards work using pcmcia-cs.

    No mention is made of the access points, which are important if you want to easily hook up to your wired LAN. Of the ones I've tested, it comes down to two: Apple and Cisco. The Apple Airport can be configured via a third party Java client which works fine under Linux. It's also dirt cheap (~$280). The downside is that it is not a high performance solution, and it can only use one encryption key. If you want performance and flexibility, buy a Cisco. It can be configured via web, telnet, and serial interfaces. All encryption is done in hardware so it is far and away the fasted 802.11b solution I've seen. Most vendors do the encryption in software, and take about a 20% performance hit with it. Which would be fine, but you pretty much have to use encryption. If you're not, you are opening up your network connection to all your neighbors.

    All the other access points I've tried use Windoze-only configuration clients (3Com and Lucent). Some of them try to prevent compatability by not allowing you to set the encryption keys directly (3Com and Apple(only applies if you use Apple's software instead of the Java client))

    Overall, this stuff rocks though. I have an Apple Airport at home. Combined with my DSL line, it is awesome. I can use my laptop anywhere in the house. Sit on the sofa and play games, check email in the kitchen, whatever. The 802.11b is much faster than DSL, so you don't notice a performance hit at all.

    I would also recommend only buying 802.11b 11Mbps hardware if you want to use it other places. There are two coding techniqes allowed in 802.11. One is Direct Sequence Spread Spectrum (DSSS), which runs from 1Mbps to 11Mbps. The other is Frequency Hopping Spread Spectrum (FHSS) which maxes out at 2Mbps. The two are 100% incompatable. They will not communicate in any way at all (except possibly some interference.) So, if you buy cheap 2Mbps cards, there is a good chance that they are FHSS and will not work with 11Mbps DSSS equipment. Spend the extra bucks and get 802.11b equipment. You will appreciate the extra speed and compatability. If you can find 2Mbps DSSS cards, they should talk to 11Mbps equipment fine (at 2Mbps of course.)
  • Well, that would be a savings of nearly $800-1000 (when you included 802.11b's access point and LAN cards together) and HomeRF now matches 802.11b's 11mbs.

    Why would I be so foolish as to include the access point?

    As for the "now matching" speed; I define "now" as "I can go into a store and buy one". Unless every web page I've checked is mistaken, 11Mbs HomeRF doesn't meet that qualification.

    My understanding is that Linux plans are in the works for both.

    Neither Vincent Cerf, Al Gore, nor God herself can transmit packets over a plan; it requires actual products with actual drivers.

  • Will that work point-to-multipoint (which is what I meant by a proper LAN)? So if I've got three or four wireless devices, I can serve them all simultaneously off a single 802.11b card in peer-to-peer mode with no need for an access point?

  • You know a way to make 802.11b work as a LAN (ie, not just peer-to-peer) without an access point? Do tell.
  • Another idea of Tesla's was the idea of using the Earth's rotation and magnetic field to generate electricity. You could set up giant coil towers that would be dragged through the magnetic field via the Earth's rotation.

    Would this really work? I thought that the magnetic field was more-or-less also fixed to the Earth's rotation (ignoring its ordinary non-rotationally related fluctuations)? Wouldn't coils attached to the Earth be stationary relative to the Earth's magnetic field?

  • These are the advantages of NOT running in ad-hoc mode:

    a) Gateway/access point can act as a repeater
    b) With multiple gateways, you can hop in a cellular fashion between access points as you roam.

    Currently, all Linux drivers will only run the card in ad-hoc mode, with the exception of the project. (Or at least, that's what I believe the difference between the AV project and the already-in-kernel drivers is.) I recall in a discussion with some other people a while ago that you can run a card in full access-point mode, but you have to implement a full 802.11b stack in the card driver. I was then told that the only cards such a stack was implemented for were Harris PRISM chipsets. Note that the AV project listed all of their supported cards as being based on or similar to PRISM based cards.

    Peer-to-peer 802.11 may be a LAN, but it's a pretty sucky LAN compared to the features you can get with the same hardware and the right driver.
  • by mOdQuArK! ( 87332 ) on Wednesday October 18, 2000 @07:52AM (#696920)
    Heh - maybe there'll be an evolutionary mutation which will allow our bodies to ABSORB all this radiation and transform it into energy that our cells can use, so we can stay energized in a high EM field without eating any calories.

    On the other hand, this is much more likely to happen for bacteria first, so that's probably not such a good idea...unless we figure out the genes necessary to do it to ourselves first :)
  • by clinko ( 232501 ) on Wednesday October 18, 2000 @05:36AM (#696921) Journal
    Wireless Electricity Has Been Done. And A long time ago by Tesla in 1899.
    Here's The Link []
    "Tesla spent his remaining funds on his other inventions and culminated his efforts in a major breakthrough in 1899 at Colorado Springs by transmitting 100 million volts of high-frequency electric power wirelessly over a distance of 26 miles "
  • that linux is getting more and more support from the HW markets. On another note, I can see how this can be a great thing for transmeta if the prices of wireless hw drop. From what I understand, transmetta is aiming to create various linux appliances. Well, what about actuall _appliances_. Web access from the kitchen, the bathroom, and the kids play room, all utilizing wireless technology and access terminals with a small footprint. I know for one that I want to have access to various computing tools in other places than just my desk. And there is no real easy way to do alot of wiring without doing it when the building is first constructed. just a thought

    "sex on tv is bad, you might fall off..."
  • ... if only we had wireless electricity ;)

    This is something that Nikola Tesla was working on, actually. The entire theory behind the Tesla Coil was that it could transmit electricity through the air to be converted into useful power at the home. The problem was, Westinghouse dropped his support of it because it became difficult to charge people for it.

    Another idea of Tesla's was the idea of using the Earth's rotation and magnetic field to generate electricity. You could set up giant coil towers that would be dragged through the magnetic field via the Earth's rotation. This could be converted and then retransmitted through Tesla Coils to power peoples homes, cars, airplanes... The possibilities of wireless power become almost endless.

    My theory is not as strong as it used to be, though. Anyone else have a more thorough grounding in these ideas?


  • Didn't Benjamin Franklin tap into this using a kite, a key and a storm?
  • And check out Absolute Value Software: Mark's working on a simple router/gateway (that runs Linux) and looks extremely promising.

    Maybe my brain fell out of calibration this morning, but I can't find what you're talking about there under 'products' or 'projects'. As far as inexpensive routers go, if someone can use one that isn't wireless, I really like my Linksys [] . It works great as a router/firewall and lets me connect all of my home computers to the internet via a single cable modem.

  • by bconway ( 63464 ) on Wednesday October 18, 2000 @05:40AM (#696932) Homepage
    The article really only delves into what the techonology itself is, and doesn't even mention how well these devices work under Linux. There is a stunning article in the August issue of Linux Magazine that you can find here [] that demonstrates setting up wireless networking in your home and incorporating it into existing networks. Unfortunately, I don't think the article is featured online. If you'd like to see it and can't find a copy of the magazine, feel free to mail Linux Magazine and ask [mailto].
  • you can demonstrate wireless power in your home:

    1. take a tupperware (or similar) bowl
    2. put a few inches of water in it
    3. float a standard light bulb in the water
    4. put the bowl in a microwave, and start!

    yes, it seems scary. I have no idea how it works or what the risks are. I do know that I've seen it/done it dozens of times and the light bulb glows on and off. Eerie.

    Anybody know how it works? I'm trying to float my laptop now, I'll let you know how it works.

  • Just to be completely redundant or something...

    Microwave ovens don't have the power to break molecular bonds. They heat food by vibrating water molecules (that's why the food heats but not the plate). The water isn't broken up.

    But wouldn't it be cool if it *was*? Hydrogen and Oxygen go boom in the kitchen.
  • HomeRF is just going to cause problems. Who needs it? Another incompatable standard running in the same frequency band which offers no advantages whatsoever. At best, it will work just as well as 802.11b. There is nothing about HomeRF vs. 802.11b which makes one cheaper than the other. Apple is pushing 802.11b access points for under $300. Is HomeRF going to be less? I doubt it.

    What makes this stuff cheap is economies of scale. If the same folks that are spending all this effort competing with 802.11b just started making and selling 802.11b equipment we would all be better off. They could help grow the 802.11b market which would push prices down. But no, it's another example of companies trying to segment the market and screw the consumer to jack up their bottom line.
  • The Apple Airport is a $300 direct-sequence 11 MB 802.11b Ethernet-to-Wireless base station. It connects directly to 10-base-T Ethernet and operates either as a bridge, repeating all packets, or as an IP masquerader and DHCP server. It can serve DHCP to Ethernet as well as the radio link, and serves up to 10 DHCP hosts. It is also a DHCP client. It comes configured to be a DHCP client, IP masquerader, and DHCP server, and thus you can plug it into the typical DSL connection and it will serve your local network immediately. The software that comes with it is Mac-only, but there is a Java application on the net that manages it. The management protocol is SNMP, so a native Linux application to manage it would be easy enough.

    I am running the Airport as a bridge, with my Linux server as the DHCP server with dynamic DNS and IP masquerader. I run it this way so that I save one static IP number (otherwise I would have to give the Airport a static IP), and so that I get dynamic DNS (which the Airport doesn't provide). The laptops use the Lucent Wavelan "Gold" with the kernel Wavelan driver and the Debian PCMCIA and wireless-tools packages.

    This works great for toting the laptop around the house so that I can dip onto the net while watching the baby, etc. And it's cheap, too!


  • First, peer-to-peer _is_ a LAN. Local area network, right?

    But if you want it to talk to the rest of the network, look at a good article at NullDevice. Just add a wireless card to your existing Linux router.... []
  • Actually, the fact that my post got moderated up as funny pretty much proves the point I was trying to make. Slashdot is the perfect example of people being told to conform, but all the while we are supposed to believe that by conforming to 'the Slashdot way' we are in fact standing up for our individuality. It is really saddening. Really, really disheartening as well.
  • Signal Ground [] did a review [] of Enterasys Networks' [] Wireless LAN offerings. They are 802.11b compliant (11Mbs), offer Linux drivers and the sources, and well, you can read the article for yourself.

  • I believe the AC that said 26 is right. I can't remember for sure, but I think that's about the time I started getting that bonus.
  • Just as another datapoint, I have been running the webgear aviator 2.4 cards under linux for a year now, and they work like a champ.

    I got both PCMCIA cards, complete with 2 ISA adapters, for $150 or so from

    Not the fastet throughput (around 75k bytes (not bits!) per second), but more then adequate for most applications... it is still 10 to 20 times faster then your cable modem / dsl connection.

  • What's so special about Wireless LAN's as opposed to normal (Wirefull?) LAN's?

    What's special is when you find a good new pr0n site and you want to take the laptop to the bathroom with you!
  • You need wireless electricity? There are these neat things called batteries that you can put into laptops so that you can carry and run them just about anywhere for several hours without being plugged in. Ever heard of 'em? They're really neat.
  • Stand under a tree in a nasty rain strom.

    Of course, the problem is one of control. Will you get killed or merely sterilized?

    As long as you're out of the breeding pool... :-)
  • Considering how concerned folks are these days about the possible health risks of EM from cell phones, I hate to think about the idea of being exposed to thousands of watts of microwave transmissions (or whatever EM wavelength) ALL THE TIME...
  • It lights because the magnetron in your microwae produces a voltage potential across the light bulb's contacts (more precisely, across the filiment itself). It's the same principle as a flourescent bulb lighting up around high voltage (actually while inside a high voltage field).

    you should check out [] for some kewl pictures of high voltage stuff; many have a dummy with a round flourescent bulb on his head. cool.
  • Unfortunately doing this kind of power transmission makes any kind of communication impossible. Think of it as full-band signal jammer. so you've got a choice: transmit power or use radio, cellular, tv, etc. can't do both.
  • The on/off period measured in seconds is probably your magnetron being turned off and on; to really explain that you have to know how a microwave works.

    The magnetron generates microwaves that heat up whatever's in the microwave. The magnetron in most microwaves is not always on, but turned on for a certain period (a second or so) and then off again, and the cycle repeats. This helps distribute the heat, instead of frying whatever happens to absorb the microwave energy the best (anything conductive absorbs the energy very well, non-conductive not very well).Incidently, this is how 'defrost' works on a microwave; the 'on' cycle is much shorter than the 'off' cycle. In the off cycle only the microwave's fan is operating.

    So, the periods where the magnetron is 'on', the light bulb is lit; while the magnetron is 'off', the bulb is too.

    I'm not positive why it wouldn't work on Xmas tree lights. If you're throwing the entire cord in the microwave, the microwaves are probably getting 'absorbed' by the cord; if you're doing it one bulb at a time, it seems to me that they should work...unless they're burning out real fast.
  • There's no point in amplification at the base if you don't amplify the other station (the one in your laptop, in this case) too - it's only one side of a 2-way connection. There is a point in a better antenna, because that gain works in both directions, although we are talking about a 3 dB gain here, not 14.

    Note also that once you modify it, it's not a Part-15 device any longer and you should have a license.


  • But like I said, this is an artificial segmentation of the market. There is no reason that you can't have "business" grade 802.11b equipment with say, hardware encryption, connectors for external antenna's, support for thousands of simultaneous clients, a high price point (like Cisco). While at the same time having "home" grade 802.11b with no external antenna provision, software encryption, and a low price point (like Apple).

    It's like saying that we should have two differnet processor standards because businesses like to buy higher quality PC's than most home users. It doesn't make sense. You can make cheap x86 PC's, and you can make expensive ones. Just like you can make "business grade" 802.11b and "consumer grade" 802.11b. But don't you want your software to work in both places? Does it make sense for me to have two wireless cards for my laptop? One for home and one for work? Of course not.

    Like I said, this is just Intel and some other folks trying to segment the market so that they can dominate that segement. My opinion is that rather than compete in the 802.11 segment, they want to create their own segment. The fact that this strategy offers no advantage to the consumer whatsoever is irrelevant to them.
  • The minimum energy required to break the chemical bonds in your DNA and cells is carried by photons of ultraviolet light. Unless your network card starts lighting up your black light posters, you're safe.
  • It works.. sort of.

    The problem is that the losses are so high that to get any practical level of power from the receiving stations you would need to transmit huge power levels. Thermodynamics and all that.

    The Tesla Coil is basicly the first radio transmitter. It's a spark gap transmitter. The signal on the receiving end is strong enough to light bulbs and such. But nowhere near the levels used by a typical home today. And wiring is cheap enough now that the costs outweigh the benefits.

    The idea of wireless power was an interesting one. And it is how radio works. Comparing this to modern radio may help those who don't understand yet. A modern radio receives a signal from a "station". This signal is typically in the millivolt range. The reason radios use power (batteries and such) is to power the amplifiers to make the signal strong enough to hear on a speaker. The transmitter for a commercial station typically has an output in the hundreds of watts. Yet you receive milliwatts worth of signal. Tesla coils aren't magic, they do the exact same thing.

    As for the other post about blowing the generator in Colorado Springs. It is widely decided from current coil builders that what happened is that feedback made it onto the mains. This HF feedback created an arc in the generator and fried it. Modern coilers use line filters to remove these high energy spikes to prevent damage to our equipment, like computers. He did NOT send a ground pulse to the generator. Experiments with coils today show that ground propigation is pittifull at Tesla Coil frequencies. And not that great even at the resonant frequency of the Earth. And modern materials give us more powerfull coils than Tesla himself could produce.

    As for generating power with the Earth magnetic field. Never heard of it. But it has possibility. Of course, do YOU want to figgure out how to build towers that reach into the Magentosphere? Me neither. ;)

    For those that are currious. Please check the facts. There have been numerous discussions about this stuff on the Tesla Coil mailing list. You can see archives at
  • Intel and a bunch of others are pushing HomeRF [], which will be cheaper than 802.11b. And Bluetooth [], which will be cheaper yet, will be able to provide point-to-point and point-to-multimpoint wireless data at 1Mbs, although initially its functionality as a full LAN will be pretty limited (no more than 8 devices per piconet, for example)
  • You've never had a laptop.
    I have a laptop with supposedly good battery life. It' about a year old, and with minimal use and regular battery maintenance, mine only lasts about 20-40 minutes on a single charge with the screen brightness all the way down, no cd or floppy, and processor on "slow".

Someday your prints will come. -- Kodak