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Wireless Networking Hardware

Australian WiMax Pioneer Calls It a Disaster 202

Posted by Soulskill
from the evolution-of-the-tubes dept.
Anonymous Coward writes "Garth Freeman, CEO of Australia's first WiMax operator, sat down at the recent International WiMax Conference in Bangkok and unleashed a tirade about the failings of the technology, leaving an otherwise pro-WiMax audience stunned. His company, Buzz Broadband, had deployed a WiMax network over a year ago, and Freeman left no doubt about what conclusions he had drawn. He claimed that 'its non-line of sight performance was "non-existent" beyond just 2 kilometres from the base station, indoor performance decayed at just 400m and that latency rates reached as high as 1000 milliseconds. Poor latency and jitter made it unacceptable for many Internet applications and specifically VoIP, which Buzz has employed as the main selling point to induce people to shed their use of incumbent services.' We've previously discussed the beginnings of WiMax as well as recent plans for a massive network in India.
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Australian WiMax Pioneer Calls It a Disaster

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  • by rueger (210566) on Sunday March 23, 2008 @10:59AM (#22836762) Homepage
    For some time now I've been taking part in WIMAX trials here in Hamilton Ontario. [community-media.com] This too was trumpeted as a glorious thing that would change the face of our city, bring us into the high tech 21st century etc.

    In practice although WIMAX seems to work OK (aside from a real lag much of the time, which may just be bad server configuration by Primus Communications), My sense is that the company isn't really committed to it. I doubt that there will be a serious public roll out.

    The idea seems great - a wireless Internet connection that works wherever you are. The reality seems a bit less rosy, and my guess is that a city wide wireless network will need a good level of customer support - not Primus' strong point by a long shot.
    • Re: (Score:3, Interesting)

      by compwizrd (166184)
      you should look into the Bell/Rogers WiMax service.. we're right at the fringe area of coverage(the antenna software claims we're linking up from about 11km away), and yet for the most part it's stable at it's 2mbit link speed.

      The 10 gb a month bandwidth limits are horrible though.
      • by empaler (130732)
        I have a 3G data subscription that used to be capped at 10 gigs, too. After that, they'd charge you through the nose. Now they've changed the TOS: There's still a 10 gig cap; they won't charge me extra after that, but they might just terminate my contract. Which is sort of good, as I never use it now that I don't waste hours in transit, and the damned thing is 60$/month (and I'm locked into the contract)
    • Re: (Score:3, Interesting)

      by Shaman (1148)
      If you have line of sight, everything is just fine. 30km is easily do-able. If you don't, then physics is just a bitch, my friends. At 3.5Ghz, you aren't going to get through much no matter what you do... the waves (or particles, depending on how you observe them) are going to be like bullets hitting water, the larger the calibre, the less far you can get the bullet with any real force.

      700Mhz spectrum should be interesting. It has monstrous value and application - however the performance will be an issu
      • by isdnip (49656)
        The 700 MHz spectrum is indeed interesting; it's next to cellular 800 MHz, and does penetrate buildings better.

        However, now that the FCC auction is over, you can forget about anything good coming of it in most areas. Verizon bought the biggest share of licenses, ATT the second-largest share; between them, they have pretty much every major license in the top markets. Their main interest seems to be keeping away competitors: A newcomer might challenge them on both price and service. So paying $15M between
    • by zappepcs (820751) on Sunday March 23, 2008 @12:18PM (#22837240) Journal
      You found the problem and didn't even mention it really:

      This too was trumpeted as a glorious thing that would change the face of our city
      Never believe the hype. WiMax has a great deal of potential but it will never eliminate the common cold, nor compete with wired broadband for a mere pittance of what wired infrastructure costs. It does however have a niche market that is quite a bit bigger than what most people think. As point to point relay for a WiFi network it has some really good uses, just as microwave links are used between cellular sites in some areas.

      If you use a Honda to haul gravel you too will be disappointed in the performance... perspective is everything and a damned good car analogy will explain anything
  • Who's fault? (Score:4, Interesting)

    by smtrembl (1073492) <smtrembl&gmail,com> on Sunday March 23, 2008 @11:02AM (#22836784) Homepage
    >Not all WiMAX operators are unhappy.
    >
    >Internode says an Airspan-supplied network is providing consistent average speeds of 6Mbps at >distances up to 30km, with CEO Simon Hackett describing the platform as "proven."

    So where exactly lies the problem? Implementation?
    • by ezzzD55J (697465)
      Internode.. first I thought it said Innertrode (Office Space), hihi.
    • Re: (Score:3, Insightful)

      by DevilM (191311)
      It is probably a combination of many different factors. A reporter should really dig in and learn more. Regardless, WiMAX can and does work. We have a network in Atlanta that sees less than 20ms latency, very little jitter and less than 1% packet loss. We carry real PRIs to demanding enterprises that work flawlessly. Unfortunately, our network is the result of blood, sweat and tears as opposed to some magic technology offered by ours vendors. This stuff is hard, but very doable.

      http://www.oneringnetworks.co [oneringnetworks.com]
    • Re: (Score:3, Interesting)

      by timmarhy (659436)
      LOL, the problem is you are believing simon hackett.

      internodes wireless offerings are not as wonderful as he is painting them.

    • by Talez (468021)
      Internode is putting the radios on masts with LOS to the base station. Buzz would be using WiMax modems with their own antennas much like other WiMax providers in the country.

      They're using 2.3GHz, 2.5GHz and 3.5GHz for the WiMax bands. Of course they're going to start having trouble with building penetration at that high a frequency. Trying to use modems with their own antennas is just stupid and is bound to be an epic fail for long distance last mile.
  • by seringen (670743) on Sunday March 23, 2008 @11:21AM (#22836884)
    I remember when a bunch of wireless guys got invited down to Intel for a private overview three or four years ago and we spent most of the couple hours trashing most of their basic assumptions about the technology. Their major response was, "well by the time it is deployed we will have figured it out"

    WIMAX isn't going to be the success that it should be because I think it was driven more by marketing than technology.

    I'm going to fiddle my fingers until they have a few more disasters till they get it working. In the meantime mesh will definitely deflate the momentum WIMAX needs right now.

    • "WIMAX isn't going to be the success that it should be because I think it was driven more by marketing than technology."
      ... and we all know that no company in the history of high technology has ever been successful using that approach!
  • Clearwire (Score:3, Interesting)

    by JimboFBX (1097277) on Sunday March 23, 2008 @11:35AM (#22836970)
    Maybe someone can clear this up- does Clearwire use WiMax or not? Wikipedia didn't make it clear. My experience with them was that they didn't either have the infrastructure or the bandwidth to support their meager customer base. The thing worked just fine during the day when nobody really used it, but during busier hours you had significant lag and flow problems- however, the download rate was still good, but you can't play games with a ping of over a second.

    To me, WiMax is the future version of 56k.
    • Re:Clearwire (Score:4, Informative)

      by Anonymous Coward on Sunday March 23, 2008 @01:00PM (#22837488)
      Lots of people seem to be confused about whether Clearwire is WiMax.

      My Clearwire device has an FCC ID of PHX-RSU2510F. The FCC docs say that it operates on 2.496-2.690Ghz. The chipset leads me to believe that it is an implementation of the Motorola Expedience [nextnetwireless.com] Wireless Broadband CPE.

      The Motorola RDM specs say that the device can operate in Expedience (up to 2W) or WiMax (up to 0.5W) modes. They also say that in Expedience mode it is a layer 2 smart bridge, while in WiMax mode it is a router with NAT, DHCP and firewall functions.

      Since my device acts like a layer 2 bridge, I conclude that it is in Expedience mode. Having just checked the Wikipedia article, I see that the first paragraph agrees:
      "Clearwire currently uses Expedience wireless technology, dubbed Pre-WiMax, transmitted from cell sites over licensed spectrum of 2.5-2.6 GHz in the U.S. and 3.5 GHz in Europe."

      So no, they use the WiMax frequency range, but they can transmit a stronger signal. That seems to be the main difference between the technologies.

      This Motorola promotional video [motorola.com] talks about some of the infrastructure and business justifications for using their Expedience gear:
    • by pm (11079)
      Wikipedia's Clearwire entry says at the top:
      "Clearwire currently uses Expedience wireless technology, dubbed Pre-WiMax, transmitted from cell sites over licensed spectrum of 2.5-2.6 GHz in the U.S. and 3.5 GHz in Europe."

      And Clearwire's site says that they are using OFDM ( http://en.wikipedia.org/wiki/OFDM [wikipedia.org] )

      Motorola's Expedience overview is here:
      http://www.nextnetwireless.com/overview.asp [nextnetwireless.com]

      So it looks like it's something like WiMAX because it's using the same type of signal multiplexing method. As Wikipedia
  • by russotto (537200) on Sunday March 23, 2008 @11:41AM (#22837008) Journal
    NLOS performance depends on a number of things, including how well the underlying technology can handle multipath and otherwise distorted signals. But the main thing is probably frequency; the higher the frequency, the worse the NLOS performance. WiMax is designed to run at many different frequencies, and the article fails to mention which one was in use.

    The issues with latency and jitter, though, probably aren't as dependent on frequency.
    • by ezzzD55J (697465)
      The issues with latency and jitter, though, probably aren't as dependent on frequency.
      Although I am no RF expert, it seems to me radio will never have significant latency or jitter, and the latency and jitter are just artifacts caused by the L2 protocol trying to compensate for poor radio performance (retransmissions at L2, bah). So if the RF worked well (indeed at lower frequencies for non-LOS) you wouldn't see these either, I think.
      • by multipartmixed (163409) on Sunday March 23, 2008 @12:10PM (#22837178) Homepage
        I am no RF expert either, but I have been on the receiving end of WiMax-ish technology, and the jitter was so bad, it was completely unusable for VoIP and even made ssh annoying at times.

        This was kit designed to work for up to 10 km (6 miles) and I had line-of-sight to the base station, which was about 150m (500 ft) away.

        Sky.. sky.. SkySomething. SkyPilot? Some kind of wierd meshy-network, I was also connected to the "master" tower, not a leaf.

        The problem, as it was explained to me, was that it has a collision/backoff algorithm not unlike that of 10-base-2 ethernet ("thin net"). So, the 50 (or so) neighbours I had, plus the leaf towers (2 of them, I think) were causing me to not get "slots" with the master on a timely basis. Hence, introducing jitter.

        So, your L2 protocol hypothesis is reasonable from my perspective, although we can eliminate poor radio performance as a direct cause. Changing the radio from broadcast to something like time or code division multiplexing would be a good solution for reducing jitter, but probably causes other problems (like decreased burst bandwidth and range).

        My solution? "*sigh* - cancel the wireless link and order me a up a T1"

        Wireless is nice because it's easy. But it sure ain't there yet.
        • Re: (Score:2, Interesting)

          by slashjunkie (800216)
          Actually, all half-duplex ethernet, regardless of physical media, even up to 100 Mbps (Gig-E doesn't support half-duplex), uses CSMA/CD [wikipedia.org]

          And any system that uses a "contention" based method to determine who can transmit, will be prone to jitter, due to the randomness of when a device wants to transmit. This includes 802.11, which uses CSMA/CA (collision advoidance, not collision detect like ethernet).

          Most wireless technology that has to guarantee specific latency to multiple clients uses some sort of static T [wikipedia.org]
        • Sky.. sky.. SkySomething. SkyPilot?
          Skynet?
  • If you build it, they will come. OR NOT.

    ISPs losing interest in citywide wireless coverage.

    http://hardware.slashdot.org/article.pl?sid=08/03/23/1213255/ [slashdot.org]

    Is patience in order?

    In the '90s I could not drive from Oklahoma City to Dallas and keep cellphone service during the entire trip. If I was in an area not serviced by my cellphone provider, I had to "force" roaming by turning my Motorola flipphone off and on, then wait.

    AT&T saw no future for data networks and the Internet!r

    • by cgenman (325138)
      I tend to think that the next generation of viable wireless data transmission backbones is already being built... by cellphone companies. Say what you will about the pokey speeds, the edge network is pretty widely available and quite useful. The same with Verizon's data services. 3G is just getting a rollout here in the US, but it is proven and solid abroad.

      ISP's have a lot of experience with wired networking, but I just don't see them having the experience or the impetus to compete with companies whose
  • It does not give the frequency range that this project is using but Wimax generally uses at least 3.5 Ghz and up to 66 Ghz, as spessified in the original draft which was 11-66 Ghz. I've seen some stories which quote Australian broadband wireless as being 4.2 Ghz. This is the frequency range that is at least at the lower limits of the microwave C-band and at 66 Ghz you are all the way into the EHF range and well past the Ka-band. By definition this kind of frequency range is extremely line-of-sight. Even
  • I chose as my ISP in Mexico City E-go [ego.net.mx], co-owned by Alestra [alestra.com.mx], the Mexican AT&T subsidiary. It started offering WiMax connection in 2003 in limited areas of Mexico City (I understand nowadays it covers most of the Central, Western and Southern parts), before even WiMax was standardized. Clients get a NextNet [nextnetwireless.com] RSU unit [nextnetwireless.com], which is basically a network bridge.
    The latency complaints you state are simply not true - I get consistent ping response times of 100ms in average (with minimum response times of around 50ms) to hosts in Mexico City, 200ms to hosts in the USA. Yes, this is about 80ms higher than wired equivalents - but it's not so much of a killer. What I do get, of course, is way higher packet loss - About 5% when things are optimal, and it sometimes gets up to 50%. But yes, I'm located at a relatively poor reception area, at one of the lower-income (this means, no incentive to place many antennas nearby) neighbourhoods in the South of the city, where the mostly flat valley where most of the city is located begins to become quite hilly. The RSU unit does not provide any means (for the client) for monitoring connection, to help choose the best possible location. It only has five LEDs (and no, they are not blue, just an unfashionable old green. Bummer.) indicating signal strength, and I always get one or two of them. I have seen signal quality significantly better when at a five-leds connection.
    Prices and speed are more or less in-par with Mexico's near-monopoly TelMex; I'm paying about US$40 for a nominal 1Mbps/128Kbps connection (512K guaranteed, whatever that means). The upstream data flow _is_ shaped to 128k, but the downstream speed is not - when the network smiles on me, I get up to 2Mbps. It is not common, though.
    I understand E-go (back then called I-go, don't ask me why) was praised as the world-first massive WiMax deployment - Even before the standard was finalized. There are several aspects of the installed network that show clearly the gear is pre-standard (i.e. extreme sensibility to position changes - If I move my RSU over two centimeters, it has to resynchronize with the antenna. This process takes around two seconds, so no big deal).
    To me, clearly, the reason it hasn't got more popular is because it is owned by a relatively small company, and has not had the muscle to stand in front of Telmex's publicity machine.
    Of course, we benefit more than DSL users from having a low client density :) E-go owns 20MHz of spectrum, which allows it to give a theoretical maximum of 70Mbps to a given area. If many too people were to subscribe, each client would have much less effectibe bandwidth alloted.
  • No doubt this story is true, In Australia the common names for Wireless Internet, which imply certain speeds or bandwidths are meaningless.

    I recently had a vacation in eastern Australia. Sydney and the surrounding suburbs, Cairns, Port Douglas.

    Like Canada, there are wireless connections everywhere, most of them locked properly by their owners.

    But, here in Vancouver, you never have to hunt for too long to find an open connection you can check your email with. I found that in the above locations finding any
    • Tesltra??? You tried talking sense into Telstra! Ha ha ha...
      Its like talking a pig into voluntarily dying to become Bacon.
      Not even parliment could talk or order Telstra into doing anything the people wanted.

      Telstra is a scum bag. Period.
      They make COmcast plus Verizon look like saints.

      They even had a funny nickname: Telescum.
  • by justleavealonemmmkay (1207142) on Sunday March 23, 2008 @04:08PM (#22838720)
    There's nothing magical about WiMax. Other frequency ranges, other protocols, that's about it.

    The only interesting thing about it is that it's not operated by traditional telcos.

    But remember, what traditional telcos sell is not telecom, they're SELLING UBIQUITOUS telecom.

    An untraditional telco would have to sell at a nonzero price ubiquitous. If they sell at zero price (or truly flat rate), a smartass will monopolize all access and resell it at real market price (what people are truly willing to pay). If the service is only sporadically available, no one will want to pay for it, or they would be better off setting up a fix line connection at the only place it works. If they comply to the two conditions, they are definitely traditional telcos.

    In the long run, WiMax is bad for the consumer. As I explained above, the business model behind WiMax can only be the "traditional telco model". But now we have two technologies with incompatible end user hardware, incompatible operator hardware. Nokia and Alcatel Lucent will sell less copies of their products to operators, thus the price will rise. Nokia and Alcatel Lucent will ask for higher fees from the opco, guess who will pay the bill. Nokia and Motorola will sell less copies of their products to end users, guess who will pay for the relatively higher cost.

    Furthermore, with WiMax vs 3G, there are now not one, but two markets for mobile data and voice. Barrier to jump from one to the other market is nonzero for the consumers. Each of the individual markets is also smaller, hence less competitive.

    Fuck WiMax
  • The article is about whether Wi-Max - a technology - is worth a shit.

    The entire first page is taken up by a flame war over free speech because the "first poster" made a comment about spectrum regulation (which might or might not have been relevant to the article as well.)

    I suggest Slashdot pare its readers back to those who can establish some connection with technology, rather than just Microsoft shills and Republicans.

    This might also ease the "my network was Slashdotted" problem.
  • by Ungrounded Lightning (62228) on Sunday March 23, 2008 @10:38PM (#22841838) Journal
    He claimed ... latency rates reached as high as 1000 milliseconds. Poor latency and jitter made it unacceptable for many Internet applications and specifically VoIP, which Buzz has employed as the main selling point to induce people to shed their use of incumbent

    Sounds like they didn't configure it right, on one or both of two issues.

    First: WiMAX has a frame rate that is an exact multiple of the 8000 frames/second rate of the telephone networks' digital carriers (and A/D converters). While this was obviously intended to allow it to carry telephone TDM signals and their associated timing (which normally isn't an issue for IP transport), WiMAX has its own, unrelated, timing issues that mandate the base stations be synchronized - to each other and preferably to a telephony network clock or a GPS-derived clock.

    The base stations assign timeslots to each remote. They measure the propagation characteristics and (depending on the sort of base station) may adjust signal strengths, modulation rates, and/or antenna aim for the associated timeslot to obtain good communication, and may pick a timeslot that is currently "quiet" on the antenna / antenna-aim appropriate for the remote in question.

    The problem is that multiple subscriber stations between two base stations (perhaps not adjacent ones) that are reusing a channel may both be "audible" to both base stations - perhaps due to using non-directinal antennas, perhaps due to reflections. If the base stations assign overlapping timeslots to their peered subscriber stations they will interfere. So the base stations try to assign their subscriber stations "quiet" slots - i.e. slots that don't already have interference from another nearby base station's remotes.

    Now that's just fine if the base stations' clocks are synchronized. The timeslots hold a constant relationship to each other and a quiet slot stays quiet. But if the base stations are not synchronized their relative framing drifts. So one base station's subscriber's slot may drift into that of another base station's subscriber, resulting in a drop of the link quality. Then the base stations readjust the configuration - perhaps moving the subscriber stations to new slots. But these do the same thing. Over and over. Result: Links keep flaking out and control traffic is massive.

    With the base stations synchronized and the subscriber stations carrying VoIP or other fixed-rate stream traffic, the stations will tend to hold on to quiet slots that march along with the stratum-III timing regularity of telephone carriers.

    The second Quality of Service issue is packet priority. The routers at both the subscriber and base stations should be identifying the VoIP (or other fixed-bandwidth streaming) flow and giving its packets priority over other traffic on the link. That way the (limited and constant bandwidth) voice packets can take the preallocated slots every time while any additional variable traffic waits for the necessary additional slot allocation. If this is not done, other traffic (such as file transfers and web browsing) will keep "stealing" the time slots out from under the time-critical VoIP / streaming packets, resulting in long and variable latencies - horrendous jitter. If it IS done (and the link is stable due to the base-station timing synchronization), the VoIP flows will have jitter characteristics virtually identical to those of telephony TDM networks.

    (This, by the way, is why "network neutrality" can't be reduced to "treat all packets the same" if you want to share the same IP network between streaming services such as video and VoIP and best-effort services such as file transfers and browsing.)

  • Security is another concern, in long distance links and metro wifi. If I have the hardware, I can listen to what you say, and speak my piece to the network too. I may have to break the encryption, and I may have to spoof a MAC, but if you can talk to a machine on the airwaves, so can I. I can also MITM most communications rather easily, and poison communications. Metro wifi and wireless point to point links are not replacements for cat6 droplines/FIOS.

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