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Beamforming: The Best WiFi You’ve Never Seen

Angelini Weighs In On Beamforming At Home

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.

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.