Technology Frequently Asked Questions

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.

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.

Is BeamFlex a standards-based technology?

Yes. BeamFlex applies MIMO diversity techniques to standards-based 802.11 a/b/g/n technologies to eliminate dead spots, increase range and performance for all standard 802.11 devices. For example, 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. Unlike all other approaches, BeamFlex gives users all the benefits of MIMO without the cost or complexity.

How does the BeamFlex technology work?

The newest RUCKUS product is equipped with a compact, internal antenna array with twelve high-gain, directional antenna elements capable of forming 4096 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 multipath 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 802.11 Wi-Fi 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 data, voice and video applications. The BeamFlex technology alone extends the range and throughput of standard 802.11 clients by 200 to 300 percent.

What is MIMO?

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 antennas 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 radio chains and signal paths to simultaneously transmit different data elements, where the receiver “recombines” the signals and data elements, ideally resulting in higher throughput (for more detailed information, please download our whitepaper on smart antenna techniques).

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.

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.

Won’t 802.11n solve all my problems?

The new IEEE 802.11n standard represents a significant advance in Wi-Fi technology with physical data rates up to 600Mbps, which promises a tremendous leap in performance and coverage over its predecessors, 802.11a and g. Yet users won’t see much of this bandwidth because other vendors of systems based on 802.11n do little to control over radio frequency (RF) variability beyond integrating more radio chains and antennas.

The typical response to RF impairments within the 802.11 standard is to lower the data rate, increase the transmit power and/or move to a cleaner RF channel. Unfortunately, power and channel adjustments are not always viable due to regulations and environmental constraints, and reducing the data rate yields lower throughput and increases the noise level in the environment.

Fundamentally, most 802.11 systems utilize omni-directional antennas that radiate energy equally in all directions. This is highly inefficient and creates interference for neighboring networks. Moreover, with 802.11n, omni-directional transmissions by multiple radio chains can actually have a negative effect on system performance and reliability if the antennas are insufficiently spaced or improperly oriented.

RUCKUS’ Smart Wi-Fi technology combines BeamFlex advances in miniaturized multi-element antenna design and sophisticated RF routing software to direct signals onto the best paths in real time, to deliver the highest possible performance and reliability in ever changing RF conditions. It also features SmartCast client- and media-intelligent QoS to optimize multimedia transmissions. With 802.11n, RUCKUS Smart Wi-Fi has been extended to optimize antenna operations with multiple radios and intelligent channel utilization software to overcome many of the challenges in realizing 802.11n’s true potential.

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. Real-time media and voice over Wi-Fi applications need stable, predictable delivery of short frames. Specifically, jitter, latency, and loss must all be minimized when carrying real-time traffic. Variability in packet inter-arrival time produces jitter, manifested as audible gaps. Delayed delivery or loss of streamed audio or video packets can be smoothed through buffering, but VoIP packet latency can render phone calls unusable.

The solution is to have the system use a per-client, per-traffic-class QoS methodology so that every client and every traffic flow is given the right prioritization. RUCKUS Smart Wi-Fi technology incorporates SmartCast to optimize traffic management algorithms to ensure adequate, on-demand bandwidth for multiple voice and video streams while maintaining adequate bandwidth for data applications. Accomplishing this requires real-time measurement of per-device QoS and algorithms that continuously adapt to the changing RF environment.

In addition, the WLAN is optimized for voice by supporting industry standards Unscheduled Automatic Power Save Delivery (U-APSD) that greatly improves battery life for the client.

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.

Don't I just need a Wi-Fi product that supports the 802.11e or WMM (Wi-Fi Multimedia, a Wi-Fi Alliance interoperability certification) to make voice and video work?

WMM and 802.11e were intended for adding basic QoS features to IEEE 802.11 Wi-Fi networks by prioritizing traffic according to four access categories: voice, video, best-effort and background. However, they require complex configurations and cannot differentiate between applications at the same priority.

SmartCast QoS automatically detects data, voice, and IPTV traffic and prioritize 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 Wi-Fi products in the market.

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.

What's different about RUCKUS' Smart Mesh Networking technology?

RUCKUS Smart Mesh Networking is unique in that it provides for a high-speed 802.11n mesh backbone link between mesh APs. In addition, Smart Mesh Networking is truly self-configuring. The AP takes on the appropriate personality of a root, intermediate mesh node, or leaf node, dynamically, and without any user intervention. This is unlike conventional WiFi mesh systems, where such personality settings have to be statically configured ahead of time by the user, which is both time-consuming, and also non-optimal, as best paths change due to interference and other real time network changes.