Technology Frequently
Asked Questions
1. What are BeamFlex and SmartCast?
They are patent-pending smart antenna and RF traffic engineering technologies (respectively) embedded into every Ruckus system.
BeamFlex is MIMO smart antenna technology and represents the industry’s most advanced multiple input/multiple output (MIMO) antenna implementation of its kind. It combines a compact internal antenna array with expert system control software. The result is an intuitive Wi-Fi system that continuously ranks the best antenna pattern for each receiving device, constantly reconfiguring itself in real-time as interference is encountered. BeamFlex steers RF signals around interference to eliminate Wi-Fi dead spots while increasing the range and performance of the Wi-Fi network.
SmartCast is a very sophisticated traffic inspection and classification engine that provides a number of unique functions such as remote RF monitoring, quality of service and application-aware content parsing. SmartCast ensures that different traffic types are each handled according to their specific requirements.
Combined, SmartCast and BeamFlex provide the predictable performance needed for picture-perfect multimedia content delivery.
2. Can’t I just use any Ethernet-equipped access point and adapter for Wi-Fi video?
While it is possible to use off-the-shelf APs and adapters for wireless video streaming at very short distances (less than 20ft / 6m), most homes and apartments do not benefit from such conditions. Most urban home environments are very “noisy” with microwave ovens, cordless phones and neighbor Wi-Fi noise – all of which introduce interference and degrade wireless transmissions. In turn, off-the-shelf wireless solutions aren’t suitable for IPTV over Wi-Fi. This has been the central problem that has plagued Wi-Fi from being the universal networking infrastructure for all voice, video and data communications in the home. Ruckus has solved this exact problem.
3. Is BeamFlex a standards-based technology?
Yes. BeamFlex applies MIMO diversity techniques to standards-based 802.11 b/g technologies to eliminate dead spots, increase range and performance for all standard 802.11b/g devices.
Any 802.11 b/g client station that associates with a BeamFlex powered AP can instantly benefit from the increased range and throughput, with no configuration changes required on the client. Ruckus Wireless will extend BeamFlex support for other standards-based 802.11 technologies, including 802.11a and future 802.11n. Unlike all other approaches, BeamFlex gives users all the benefits of MIMO without the cost or complexity. BeamFlex overlays any existing 802.11 chipset giving equipment manufactures complete extensibility to future 802.11 technologies.
4. How does the BeamFlex technology work?
Each Ruckus product is equipped with a compact, internal antenna array with six high-gain, directional antenna elements capable of forming 63 unique antenna patterns for massive diversity. The BeamFlex expert system control software continuously ranks the optimum antenna patterns for each receiving device, using the inherent feedback mechanism built into the 802.11 MAC layer protocol. This knowledge enables the BeamFlex antenna array to reconfigure itself in real-time, detecting and adjusting for both spectral and multi-path interference as well as neighbor network noise. By selecting the optimum antenna pattern for each receiving device, BeamFlex enables better signal quality and higher communications speeds over the 802.11b/g network. The massive diversity of the BeamFlex antenna systems allows Ruckus devices to find and instantly select from many quality signal paths in a changing environment to sustain the baseline performance required for audio and video applications. The BeamFlex technology alone extends the range and throughput of standard 802.11b/g clients by 200 to 300 percent.
5. What is MIMO?
It’s the next generation of Wi-Fi. MIMO stands for multiple input; multiple output. It’s an antenna technology for wireless communications in which multiple antennas are used at both the transmitter and the receiver. The antennas at each end of the communications circuit are combined to minimize errors and optimize data speed. MIMO generally operates in two modes: diversity mode and spatial multiplexing mode.
In diversity mode, MIMO systems use multiple antenna arrays to maximize range and throughput between two wireless devices by choosing the best signal path between them. In spatial multiplexing Mode, MIMO systems use multiple signal paths to simultaneously transmit different data elements, where the receiver “recombines” the signals and data elements, ideally resulting in higher throughput. Spatial multiplexing requires industry standardization for multivendor interoperability, while diversity methods can be implemented on just one side of a communications link (for more detailed information, please download our whitepaper on smart antenna techniques).
6. Does the Ruckus support MIMO?
Yes. BeamFlex implements diversity mode but not spatial multiplexing mode, which currently has not been standardized. We use multiple antennas at each end to establish the best possible path at any given time for any given packet. Implementing spatial multiplexing mode today would require proprietary algorithms to be supported on both the AP and the client stations to attain its benefits.
7. I’ve seen some new higher-speed Wi-Fi routers and adapters that tout 108Mb/s, MIMO and Pre-N standard. How do the Ruckus products compare?
802.11N is the next-generation standard for Wi-Fi. It is currently in the early stages of standard development and a draft standard is not yet available. The consensus in the industry is that the standard will be finalized by late 2006/early 2007. The point to remember is that sending video over Wi-Fi requires much more than bandwidth and network capacity. It requires reliable and predictable network characteristics. This is especially challenging with Wi-Fi.
The current .11N proposals have centered on the use of MIMO technologies to increase range and performance. However, there are many modes of operation in MIMO and within each mode, many options. Some of the MIMO techniques, such as spatial multiplexing, requires changes to both the network and the client and must be standardized to ensure multi-vendor interoperability. Other techniques such as antenna diversity can be implemented on only the network or the client side and be interoperable with all standards-compliant devices in the same network.
Early “pre-N” or MIMO products that implement spatial multiplexing, such as the Belkin Pre-N wireless router and notebook network card, and the Linksys SRX MIMO router/access point and adapters, require a dual-end solution, i.e., both the router/AP and the client adapter from the same vendor must be used together to deliver the promised benefits. Worst yet, their spatial multiplexing algorithms are non-standard and will be obsolete when 802.11N is available. Lastly, these products are optimized for managing PC-centric data applications, not video applications.
The Ruckus approach is completely standards complaint. Our BeamFlex technology, while providing the benefits of MIMO’s diversity techniques, works within the 802.11b/g standard. With the Ruckus AP, the range and performance advantages benefit all 802.11b/g clients without any upgrades on the client side. The Ruckus products are also tuned for video applications, with innovative, advanced QoS and multicast IPTV extensions that are not available in any other products in the market.
8. Why are the SmartCast QoS features necessary?
Off-the-shelf WLAN devices don’t differentiate between the various traffic types (voice, video, data) on the network. All traffic is created as equal, and thus the WLAN typically works in a “first-come first-served” fashion. Frequently, it is the PC-data clients transferring large files that capture much of the bandwidth. Video applications require constant, uninterrupted bandwidth. If video is transmitted while Internet surfing, email access or downloads occur, the video quality will surely suffer.
Ruckus products incorporate a unique QoS approach for multimedia. This SmartCast QoS optimizes traffic management algorithms to ensure adequate, on-demand bandwidth for multiple broadcast quality video streams while maintaining adequate bandwidth for data applications. In turn, SmartCast QoS ensures a satisfactory viewer experience.
9. Don’t I just need a higher-speed Wi-Fi product to make IPTV / video work?
Not necessarily. Adding bandwidth to the Wi-Fi network will not automatically enable wireless video distribution. Video requires a consistent, low-delay availability of network bandwidth. Newer WLAN technologies such as spatial multiplexing mode in MIMO increases the wireless data rate but will not guarantee bandwidth consistency. As radio signals ebb and flow (due to motion or interference from Bluetooth phones, for example) and other applications compete for the WLAN’s bandwidth, transmission errors and delays will still occur.
10. Don’t I just need a Wi-Fi product that supports the 802.11e draft standard, or WMM (Wi-Fi Multimedia, a Wi-Fi Alliance interpretability certification) to make IPTV / video work?
802.11e is intended for adding basic QoS features to IEEE 802.11 networks. WMM, which is based on the 802.11e draft standard, prioritizes traffic according to four access categories: voice, video, best-effort and background.
However WMM does not provide guaranteed throughput, nor does it define any mechanism for automatically classifying traffic into the four access categories. Products that support WMM typically shift the burden to the user, requiring complex configurations that are generally too challenging for a typical consumer. SmartCast QoS automatically detects video and IPTV traffic and prioritizes them according to bandwidth and delay requirements. In addition, per-station queuing on Ruckus products provides much finer granularity and higher precision for bandwidth prioritization compared to other consumer Wi-Fi products in the market.
11. Is the Ruckus AP the same product as the Netgear RangeMax Smart MIMO router, which is also based on Ruckus Wireless technologies?
NETGEAR’s RangeMax router only integrates Ruckus BeamFlex technology and is positioned to extend the coverage and capacity of Wi-Fi for use in data applications.
In other words, NETGEAR’s RangeMax router is optimized for high performance data, not video. It does not support Ruckus SmartCast technology.