We had the pleasure of visiting Ruckus Wireless at NFD5. Visiting them was a little out of the ordinary, because there is a separate Wireless Field Day event, however, it gave those of us who have little wireless experience a chance to learn about one of the most advanced wireless systems on the market.
I was really impressed with what they do for wireless. They are positioning their products to be faster, more reliable, and more trustworthy. GT Hill explained the “trustworthy” part at the start of the session. Wireless has been untrustworthy because you can’t trust that it will be available with the performance you want, when you want it. GT did a great job of explaining the different modulation and encoding schemes that are used in wireless networks as well as the impact of Signal-to-Noise Ratio (SNR) on wireless performance.
GT Hill Introduces the Wi-Fi Market and Ruckus Wireless
Most vendors tend to use the reference design provided by the radio vendors. Ruckus does their own design. In addition, they go much further with the design of their antennas. The systems we saw had complex antennas that have nineteen segments. The multi-segments allow the controller to perform beam forming on transmit. The antennas can also handle multiple polarization, which is important for communicating with mobile devices whose polarization are constantly changing. These changes are for transmit mode. The antenna steering (beam forming) allows lower power to be used, which reduces excess RF noise in the environment. This is particularly important in the zones where a node can see multiple APs.
I was impressed and asked if they use the wifi preamble to adjust the antenna steering to optimize the received signal. No, they currently don’t steer the receive pattern. If they did, it would be super cool.
I think that there are some things that they can do to use antenna steering for both transmit and receive (maybe they have and aren’t talking about it yet). They would have to start out with an omnidirectional pattern, but then make small tweaks to the antenna pattern to measure the maximum and minimum received power levels from a client. It should be possible to determine the best pattern to use for a given client in just a few packet exchanges. But I’m not the RF expert, so this is brainstorming on my part.
Their objective is to make wireless networking operate at levels that are comparable to wired communications (1Gbps and above). The application of smart engineering like that described by Ruckus will eventually make it happen.
How will they get to 1Gbps and beyond? Sandip Patel talked with us about the direction of the WiFi standards and how the current channels will be combined to get to the higher speeds. I found these presentations to be very technical and yet easy to follow.
Sandip Patel of Ruckus Wireless Places 802.11ac in the History of Wi-Fi
Tom Hollingsworth, another NFD5 delegate, introduced 802.11ac with the quip “802.11ac is the SDN of wireless.” Several techniques are used to increase throughput. The 11ac wireless system uses the 5Ghz spectrum, grouping channels to achieve higher throughput (see the video for a more accurate description). Packets are grouped together in one transmission, called Aggregation MAC PDU (AMPDU). The transmission can be sent to one client or up to four clients, using the MIMO (Multi-Input, Multi-Output) system. Using their antenna system, they can transmit to four clients who are not in the same geography (e.g., four clients located 90-degrees from one another at varying distances).
I’m really impressed with the innovation that Ruckus uses in their designs.
Disclosure
The vendors for NFD 5 are paying my travel expenses and providing small gift items. Ruckus is providing one of their standalone APs, which will allow me to do an evaluation against the 802.11n equipment that I currently use at home.
-Terry