Mobile devices are moving even when users are sitting at their desks. Flipping the landscape of a tablet or smartphone, or adjusting the angle of a laptop, can reduce Wi-Fi signal reliability and degrade wireless network performance. With more mobile devices entering the enterprise every day, businesses must adapt the wireless LAN to account for not only increasing numbers of mobile devices, but also devices that are constantly shifting their orientation toward access points.
Mobile device orientation changes degrade wireless network performance
Radio frequency management technologies like beam steering or beamforming can help wireless LAN infrastructure adapt to changes in mobile device orientation, said Craig Mathias, principal with the Ashland, Mass.-based Farpoint Group advisory firm.
"Every time [a user] changes the orientation of their mobile device, they are actually changing the way that device talks to the Wi-Fi network and how the signals communicate with the access point," said David Callisch, vice president of marketing for Ruckus Wireless Inc., a Sunnyvale, Calif.-based wireless LAN vendor. "Users could be walking around the office, changing how they hold a device and they can see really different levels of performance because access points can't account for those changes."
Ruckus recently introduced BeamFlex+, a software upgrade to its BeamFlex beamforming technology that enables a Ruckus access point to be "polarization-agnostic" -- unlike traditional, fixed access point antennas -- and automatically adjust to deliver the best performance, regardless of the way a client device may be sending Wi-Fi signals as their orientation is changes.
BeamFlex+ beamforming technology uses maximal ratio combining technology and horizontal and vertical polarization technology -- instead of the typical omni-directional antennas that radiate signals in all directions -- to improve the reception of signals from different orientations for more reliable communication, allowing the access points to "listen" to Wi-Fi transmissions that are sent in different trajectories from client devices, Callisch said. The software continually communicates with devices to learn the environment and possible interference sources.
"More and more, these enterprises are seeing mobile devices on their network, but had no way of addressing this new problem," he said. "Enterprises need access points that can account for changing radio frequency signals."
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The St. Vrain Valley School District in Longmont, Colorado has encouraged staff and students to bring their own devices to school at all 52 of the district's locations. Each school has a Ruckus wireless infrastructure, said Joe McBreen, CIO of the school district.
Teachers are using tablets -- mostly iPad and Android devices -- to deliver lessons and collaborate with students during class, but their legacy Cisco wireless infrastructure could not support the strain that mobile device orientation changes was putting on the network, McBreen said.
"Students and teachers could be sitting in the same spot and turn or tilt their device, and you could see the signal strength on the client device drop from full strength, to one or two bars," he said.
The school district, which has 4,500 to 7,500 concurrent, daily users, replaced Cisco with Ruckus primarily because of its BeamFlex+ technology.
"Now, when users tilt a [mobile device] in different ways, they don't experience loss of signal strength because the [BeamFlex] technology focuses energy at any given device," McBreen said.
Enterprise WLAN will benefit from beamforming
While beamforming technology capabilities may not have historically been high up on the enterprise wireless LAN wish list, this functionality is a standard in the 802.11ac specification. As organizations upgrade from 802.11n to 802.11ac, beamforming will become more widely used. The benefits of beamforming will be more obvious and widespread as more mobile devices access the network.
"[Users] will be able to bias the Wi-Fi signal to where it's most beneficial, and will produce a reliable connection, instead of relying on luck, the key element in radio transmissions right now," the Farpoint Group's Mathias said. "As the device moves, it can be tracked to maintain a good quality of connection."
While beamforming will be standardized in 802.11ac, vendor implementations will continue to have wide variability. "The vendors have to do most of the work to make sure end users get the optimal result," he said. "Just because beamforming is becoming a standard doesn't mean all users will have the same performance, and different vendors will be able to do this better than others," Mathias said.