Slashdot is powered by your submissions, so send in your scoop


Forgot your password?
Communications Wireless Networking Hardware

WiMax Is Finally Coming — Here's How It Performs 112

GMGruman writes "Carriers have promised WiMax networks for years. But will they deliver the goods, or be slow like many early 3G networks or patchy in coverage like the metro Wi-Fi attempts in most cities? This hands-on review looks at a nearly-WiMax deployment (technically, OFDM) in Reno, testing its speeds and reach, as a measure of what Sprint and Clearwire will deliver in their joint WiMax rollouts starting next month. The good news is that this time, the carrier promises look to be delivered on."
This discussion has been archived. No new comments can be posted.

WiMax Is Finally Coming — Here's How It Performs

Comments Filter:
  • by santiagoanders ( 1357681 ) on Tuesday September 30, 2008 @10:09AM (#25204171)

    From TFA:

    "To be completely accurate, the Clearwire service is not officially WiMax but OFDM, the underlying technology behind the WiMax standard. Clearwire deployed the Reno network before the WiMax standard was final, but it is practically the same technology."

  • by feld ( 980784 ) on Tuesday September 30, 2008 @10:21AM (#25204283)

    Madison, WI has had WiMAX for over a year, but it wasn't been publicly launched until January. TDS Telecom offers WiMAX not just for internet, but for phone! You get indoor or outdoor WiMAX equipment depending on how the survey of your location goes, and you also get a UPS for the equipment so it doesn't go down when the power's out.

    Residents using it report that it gives better call quality (which is probably due to poor phone lines) and say their connection is faster than landline DSL (also probably line quality, but could be less congested networks).

    Here's some infos on what we have: []

  • by jb_02_98 ( 636753 ) on Tuesday September 30, 2008 @10:25AM (#25204311)
    I've had Wimax here in southeast Idaho for a while. It seems to work ok, the only problem being that they got overwhelmed when they started the service and had some bandwidth shortages due to uptake being quicker than they had originally planned. Other than that, it seems pretty reliable and seems to work well. I'm excited to see the tech rolled out elsewhere.
  • by ajdowntown ( 91738 ) on Tuesday September 30, 2008 @10:41AM (#25204505) Homepage

    I have a good friend that works directly for the WiMax team. According to him, there are many cities all ready to go with WiMax, and the first city to sell it will be Baltimore, with two months later Washington DC and LA I believe coming on next. Then, if all turns out well, 30 cities in 2009, and by 2010, most all major metro areas being covered. My friend already has a working WiMax card at his house (here in DC) and has been using it for the past 2 months. He said Baltimore was going to be first because it is the city with the most "complete" coverage. There is even suppose to be some sort of ceremony going on with the mayor of Baltimore attending. I am also told that anyone from the DC area could potentially drive to DC to buy the WiMax cards and use it back home in DC no problem.

    My friend also said that the current limitations are with the WiMax cards, only getting about 2 megs a sec, while the ones coming next year will be almost twice as fast.

    This is a good friend, so I trust what he says, but, as always, YMMV.

  • MOBILE WiMAX (Score:4, Informative)

    by santiagoanders ( 1357681 ) on Tuesday September 30, 2008 @10:47AM (#25204577)

    WiMAX has been around for a while - the IEEE 802.16-2004 standard has been around a while, mostly for stationary links in rural or semi-wilderness areas. I know that AT&T has deployed some stationary WiMAX services in Alaska.

    The XOHM network that Sprint is unrolling is a MOBILE WiMAX network. This is IEEE 802.16e-2005. It adds additional features meant to help with mobility (e.g. Hybrid ARQ). Some of these features may or may not be present in the Clearwire service.

    There are a lot of vendors that are implementing WiMAX hardware, so one review isn't going to say everything.

  • Re:Bandwidth limits? (Score:5, Informative)

    by ajdowntown ( 91738 ) on Tuesday September 30, 2008 @10:47AM (#25204583) Homepage

    See my other post, but according to my friend that works for the WiMax project, there will not be any bandwidth cap. The reason the cellular data cards needed bandwidth caps is because the problem with the towers. Each tower for 3G technologies have about a T1 running to them, so the line can easily get saturated. From what I understand, the WiMax towers have something crazy like a 10GB line running to them, thus not having to have the same caps as the cellular networks to artificially keep usage low. He also said that the WiMax team will re-evaluate the unlimited usage after a year or so to see if it is still feasible.

  • Re:Bandwidth limits? (Score:2, Informative)

    by entrigant ( 233266 ) on Tuesday September 30, 2008 @10:53AM (#25204659)

    I think you might be missing the point for a cellular modem. It's not meant to be your primary internet gateway for all of your multimedia needs. I have an EVDO modem built into my laptop and a 5GB subscription. The point is when I'm on the road or out of the office working with a client I can send/check e-mail, use jabber, ssh, and load web pages. None of these activities come close to taxing my 5GB limit.

  • WiMax and OFDM (Score:3, Informative)

    by loose electron ( 699583 ) on Tuesday September 30, 2008 @10:56AM (#25204695) Homepage

    Just to clarify - OFDM is the modulation method used to convery data. Modulation methodology doesnt really tell you much about bandwidth and data rate, since a communication channel design can trade these properties off in an interactive manner when the design standard is defined.

    The good news is that WiMax is designed to do data over long distance (measured in Km's) rather than the the duct tape installations of WiFi, which was never supposed to be used for distance data communication. Some of the crazy WiFi installations that are out there are 5 star silly, trying to do things that WiFi systems were never designed to do.

    Some useful links: [] [] [] []

    If you want to get into the nitty gritty of the details, the IEEE has the 802.16 standards for all the details as well.
    The good news is that this time around it actualy seems to be happening. It's out there in a big way (read some of the deployments in the above links) but not widespread yet.

  • by branchingfactor ( 650391 ) on Tuesday September 30, 2008 @11:06AM (#25204805) is live blogging a test of the XOHM WiMax deployment in Baltmore []
  • by compro01 ( 777531 ) on Tuesday September 30, 2008 @11:58AM (#25205483)

    1. No. Wimax has nothing to do with wifi. Wimax is a last-mile type connection, much like DSL, cable, etc, with the capability to act like cellular broadband in the sense it does not necessarily require a fixed antenna and thus can be mobile.

    2. Maybe. I've heard thoughts of cellular service along the lines of VOIP-over-wimax, though I imagine this is several years away, if it even pans out.

    3. Provided it uses actual wimax and not a similar non-standard, it would act like a modem and connect via ethernet/wifi in a fixed mode and usb/pcmcia/expresscard/built-in/etc. when used in a mobile mode.

  • Line noise (Score:3, Informative)

    by tepples ( 727027 ) <tepples@gmail.BOHRcom minus physicist> on Tuesday September 30, 2008 @12:51PM (#25206237) Homepage Journal

    If rural residents have phone lines running into their house, they should be able to get some kind of DSL which would be ~10 times faster than dialup (300-500 kbit/s) or maybe 20 times faster (600-1000 kb/s).

    You can't get DSL if the connection from the closest access multiplexer has an unacceptable amount of line noise above the audio band. Runs of longer than two miles tend to do this.

  • High latency (Score:2, Informative)

    by wormeyman ( 797562 ) on Tuesday September 30, 2008 @12:56PM (#25206299) Homepage Journal
    I have Clearwire up here in Washington state and while i connect at 1.1mbs on my up to 1.5 mbs connection i have horrible latency due to it being a wireless connection i ping 130ms to google and get auto kicked from online servers for having too high of a ping. I would definitely agree with the final sentence in the article "If your main use is for video downloads and 3D gaming, that's another story. "
  • by Ungrounded Lightning ( 62228 ) on Tuesday September 30, 2008 @04:24PM (#25209175) Journal

    So, this is a review of WIMAX, except it's not of WIMAX it's of something else? Can we review Wifi next to see how T-Mobile's 3G service is in my area too?

    Much of the WiMax standard settled early. The physical layer was part of that. But there was a long time while some details were being hammered out.

    During this time a number of vendors came to market with equipment that conformed to as much of the standard as seemed stable and took a guess at how to fill in the rest or how the arguments would settle out. Perhaps they'd be able to meet the final standard with a firmware change, perhaps they'd need to change the hardware somewhat.

    This interim equipment worked about the same way, and as well in terms of coverage, noise immunity, multipath immunity/use, speed, etc., as equipment conforming to the final standard would. The downside for a customer WISP was potential inability to interoperate with standardized, cheap, multi-supplier equipment without reflashing, or possibly replacing, the early-adopter hardware - leading to higher costs and potential loss of future customers (such as those with conforming-only chipsets built into their laptops). The upside was that they could deploy their networks RIGHT AWAY, getting investment when money was available, establishing a footprint and a customer base (who would be hard to lure away with service only about equivalent), getting revenue from the expensive bandwidth licenses, and so on.

    So a number of companies, such as Clearwire, chose to take the risk in order to get a jump on the competition and become established in broadband-underserved areas.

    So the nearly-WiMax in question will have essentially the same properties as true WiMax, with the primary exception of interoperability with commodity WiMax hardware, making the review a useful one.

    And possibly one other thing: One of the issues with the early versions of the WiMax spec was its poor handling of doppler shift, making it unsuitable for use on cars, busses, and trains - at least when moving at freeway/railroad speed toward/away from the associated base station. (I'm not sure what happened to that. I think they did NOT fix it in the final standard. I was working with a couple colleagues on a potential WiMax startup and we threw in the towel when it became apparent that you couldn't get prototype silicon or specs from the vendors unless you were already a {VERY} large company with an established relationship.)

  • by Anonymous Coward on Tuesday September 30, 2008 @07:37PM (#25211761)
    Hi AJ: small correction: WiMAX is here now! I am the friend you refer to :) Posting anon due to various disclosure agreements, etc. We launched Monday in Baltimore, and the service is commercially available now ( [] ). Performance is also MUCH better than the "review" See the following "review of the review" at ZDNET: [] [] In short, what was "reviewed" is NOT WiMAX, and does not reflect true "real world" performance. WiMAX works wonderfully with mobile handoffs, and has better performance than the Clearwire network that was tested. Clearwire's current networks are not yet WiMAX compliant. XOHM's are.

We gave you an atomic bomb, what do you want, mermaids? -- I. I. Rabi to the Atomic Energy Commission