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Angelini Weighs In On Beamforming At Home

Beamforming: The Best WiFi You’ve Never Seen
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When William and I first started discussing this project, I was skeptical. But I was also working on an ambitious home theater PC piece that I knew could put this technology to the test in a major way.

The goal was to archive my Blu-ray DVD collection using AnyDVD HD for creating images of each disc, DAEMON Tools to mount those images, and My Movies 2 to manage them all. Of course, the data wouldn't be stored on the HTPC itself. With each image weighing in at over 40GB, I needed to move them to a networked location and stream them at full quality. Everyone I talked to said the only way to do this was over Gigabit Ethernet. Even conventional 802.11n MIMO couldn't sustain the bandwidth needed for such an application.

Sure enough, I tested 802.11n wireless products in preparation for the aforementioned HTPC story and none could keep up. I'd get smooth playback for a few seconds, then horrible audio/video corruption. Remember that it isn't enough to burst the necessary throughput. It has to be sustainable >99% of the time or you're going to get very frustrated watching a jerky movie.

Ruckus Steps Up

When Ruckus heard about my project, the company sent over its MediaFlex 7811 access point and 7111 adapter, a $349 setup based on the same technology as the enterprise-class gear William just benchmarked. Designed for streaming HD IPTV streams via 802.11n, it's spec'd to deliver between 40 and 60 Mb/s sustainable through a 5,000 square foot house. Used for that purpose, you'd be getting two or three 20 Mb/s MPEG-2 streams concurrently.

But streaming Blu-ray image files is another monster entirely. To begin, our test disc, Transformers, was hitting 40-45 Mb/s, so just a single stream would be taxing the capabilities of Ruckus' 802.11n equipment. Second, the company's access point includes automatic traffic classification, which tags multicast video packets and sends them via UDP, resulting in the performance figures seen earlier in this story. Unfortunately, an ISO is seen as a data file, not video, so it's sent using TCP, impacting performance.

Blu-ray, Wireless, Go!

Our first attempts failed miserably. With the MediaFlex 7811 and Thecus N5200 Pro NAS/SAN both connected to D-Link's DIR-655, streaming was choppy, at best. Completely unwatchable. But, after a ton of troubleshooting, I discovered two things. One, the D-Link router was slowing things down enough to cause performance degradation in the video playback. Second, the antenna array used in the access point is incredibly sensitive. Set it too close to other wireless devices and you'll throw off its throughput. In fact, representatives at Ruckus illustrated the technology's sensitivity by explaining the 7811's curved design. That's not some attempt at being industrial-cute. Rather, the antennas needed to be lifted away from the access point's onboard circuitry, which would otherwise emit enough EMI to affect performance.

Ideally, you want the AP farther away from the router.Ideally, you want the AP farther away from the router.

Fortunately, the Thecus network storage unit includes a separate LAN port, used to attach additional devices. I plugged the MediaFlex 7811 directly into the N5200 Pro, moved the AP a couple of feet away from the D-Link router, and gave the experiment one last try. Amazingly, both Transformers and Wanted (both data streams, not video) played back smoothly (separately, of course). Over a wireless network. Sustaining close to 50 Mb/s of real-world throughput. 

"So what?" you say. "802.11n has a 300 Mb/s data rate and should be good for more than 100 Mb/s of real-world throughput." Remember, doing this with a movie means sustaining that performance, and as far as I've seen thus far, no other wireless solution is able to maintain the performance needed >99% of the time to play back more than 40 Mb/s of video. For a guy who doesn't have gigabit throughout the house, enabling the ultimate media server over wireless is nothing short of incredible.

Good Luck With That?

There is a rub, it turns out, for the residential folks looking to enable a similar solution without stepping up to enterprise-class hardware. Ruckus doesn't focus on retail sales, and it instead deploys its technology predominantly through verticals. In fact, we only found one online shop listing the MediaFlex AP and adapter for sale, and both were out of stock (at the time of writing; we'll update should that situation change). You can get the hardware as part of your U-verse service if you're with AT&T, but otherwise, it's not easy to find. We knew this going into the experiment though, and can only hope that as more of the enthusiast community experiments with HTPC-type applications, hardware based on Ruckus' technology becomes more accessible to the do-it-yourself crowd.

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Top Comments
  • 10 Hide
    antiacid , August 17, 2009 1:13 PM
    awesome article! Thanks for exposing us to this great technology :) 
Other Comments
  • 2 Hide
    chinesemafia69 , August 17, 2009 8:16 AM
    wow....this owns

  • -6 Hide
    bucifer , August 17, 2009 8:42 AM
    This article started up pretty good with lots of technical data and the beamforming technology in theory but after that the goodness stopped.

    1.You cannot compare two products by testing them with a in-house developed software. It's like testing ATI vs nVIDIA with nvidia made benchmark.
    2.If you do something get it done, don't just go with half measures. I don't care if you didn't have time. You should have planned this from the beginning. The tests are incomplete, and the article is filled with crap of Rukus and Cisco.
  • -5 Hide
    Mr_Man , August 17, 2009 12:44 PM
    In defense of your wife, you didn't HAVE to use that particular channel to view all the "detail".
  • 2 Hide
    Anonymous , August 17, 2009 12:58 PM
    @Mr_Man: With a name like yours, I'd think that you'd sympathize with Chris a bit more :p  Unless (Mr_Man == I likes men) :D 
  • 10 Hide
    antiacid , August 17, 2009 1:13 PM
    awesome article! Thanks for exposing us to this great technology :) 
  • -4 Hide
    Pei-chen , August 17, 2009 1:17 PM
    Both Tyra and Heidi have personal issues and would be pretty difficult friend/mate.

    The network idea sounds better. I couldn’t get my 10 feet g network to transmit a tenth as much as my wired network without it dropping.
  • 3 Hide
    zak_mckraken , August 17, 2009 2:23 PM
    There's one question that I think was not covered by the article. Can a beamformaing AP can sustain the above numbers on two different clients? Let's say we take the UDP test at 5 GHz. The result shows 7.3 Mb/s. If we had two clients at opposite sides of the AP doing the same test, would we have 7.3 Mb/s for each test or would the bandwidth be sliced in 2?

    The numbers so far are astonishing, but are they realistic in a multi-client environnement? That's something I'd like to know!
  • -1 Hide
    jerther , August 17, 2009 2:28 PM
    There is so much invisible to understand in wireless technology!
  • -6 Hide
    ebattleon , August 17, 2009 3:01 PM
    You can of course get the same effect by having better antenna on both ends of the network. This would increase gain which would improve signal to noise ratio, which would improve data flow speeds. You would also get the same effect by boost in the power but that could get you in trouble with the law.

  • 1 Hide
    Anonymous , August 17, 2009 3:04 PM
    I'm not an expert on beamforming, but I'm surprised that it is useful at these frequencies. After all, the wavelength at 2.4 GHz is ~12 cm (~5 inches). That means that the pockets of constructive interference (the beam) are very small. Moving the receiver a few inches should make a big difference.

    Are you sure the differences you are seeing aren't simply due to higher power output? Couldn't the same improvements be obtained with a directional antenna like a Yagi?
  • 1 Hide
    Rancifer7 , August 17, 2009 4:00 PM
    So far quite an interesting technology. Its nice to know that at someone in the wireless world is striving to make something innovative!

    When all the major players sell items that look almost the same, act similarly, and perform almost the same, there is something wrong with the industry.
  • 1 Hide
    chaohsiangchen , August 17, 2009 4:13 PM
    Beam forming technology have been for a long time, but they are mostly used in military equipments. Phased Array radars, Synthetic Aperture Radar, Inverse Synthetic Aperture Radar, Plane Array Antenna and antenna for data link. Most consumer products still use Yagi or disk antenna. Cost is a major issue in the application. Military don't care that much about the cost.
  • 0 Hide
    scotty123 , August 17, 2009 4:23 PM
    sounds nice - but i won't get excited until it's available at Best Buy!

    One niggling concern, I felt reasonably safe with the unfocused cloud of RF surrounding me wherever I go, but I am not so sure about the tightly focused beam that the Ruckus provides. What happens to the poor joe who sits directly in the path of such a beam for 8 hours a day?
  • 1 Hide
    williamvw , August 17, 2009 4:39 PM
    Mr_ManIn defense of your wife, you didn't HAVE to use that particular channel to view all the "detail".

    LOL! True enough. It honestly was a reference file I had on hand for such testing situations. Angelini obviously showed a bit more wisdom in his choice of in-house test content.
  • -1 Hide
    williamvw , August 17, 2009 4:44 PM
    scotty123sounds nice - but i won't get excited until it's available at Best Buy! One niggling concern, I felt reasonably safe with the unfocused cloud of RF surrounding me wherever I go, but I am not so sure about the tightly focused beam that the Ruckus provides. What happens to the poor joe who sits directly in the path of such a beam for 8 hours a day?

    My absolutely unqualified opinion is "probably nothing." While the conditions are somewhat different, you might want to read a Tech Myths column segment I did over on Tom's Guide that touches on this issue. http://www.tomsguide.com/us/decibels-noise-canceling,review-1338-10.html
  • 2 Hide
    williamvw , August 17, 2009 5:17 PM
    zak_mckrakenThere's one question that I think was not covered by the article. Can a beamformaing AP can sustain the above numbers on two different clients? Let's say we take the UDP test at 5 GHz. The result shows 7.3 Mb/s. If we had two clients at opposite sides of the AP doing the same test, would we have 7.3 Mb/s for each test or would the bandwidth be sliced in 2?The numbers so far are astonishing, but are they realistic in a multi-client environnement? That's something I'd like to know!

    Excellent question, and one I hope to dive into in a later article. For now, I can only give you the anecdote on my opening page, running the same HD stream to two clients. Ruckus states that BeamFlex can sustain a 50 Mbps minimum per access point. Do the math on your client streams accordingly, I suppose.
  • -1 Hide
    bounty , August 17, 2009 5:24 PM
    williamvwLOL! True enough. It honestly was a reference file I had on hand for such testing situations. Angelini obviously showed a bit more wisdom in his choice of in-house test content.


    Honestly honey, it's just a reference file, I swear it's not porn. I challenge you to find HD streaming content from the internet that highlights the subtle nuance of flesh tones.
  • 2 Hide
    williamvw , August 17, 2009 5:28 PM
    bountyHonestly honey, it's just a reference file, I swear it's not porn. I challenge you to find HD streaming content from the internet that highlights the subtle nuance of flesh tones.

    Hey, the VS catalog mails to her, not me. I was merely trying to be a good husband and participate in her interests. ;-) ANYWAY. Back to beamforming, shall we?
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