Delivering the 802.11n Promise with Smart Wi-Fi
The new IEEE 802.11n standard represents a significant advance in Wi-Fi technology, promising a tremendous leap in performance and coverage over its predecessors, 802.11a and g. With physical data rates up to 600Mbps, many believe that 802.11n will replace wired networks within the enterprise and at home.
Yet there’s a significant disparity between the 802.11n promise and the actual throughput experienced by users of the current generation of 802.11n systems. While all equipment vendors have access to the same 802.11n chipsets, system-level design and packaging choices can greatly influence the actual throughput, stability and usability of individual products.
Arguably, the most overlooked and under-optimized aspect of commercial 802.11n systems is the control over radio frequency (RF) variability. A robust, responsive RF layer is central to wireless network performance, particularly for Wi-Fi which operates in the open spectrum. It is ironic that most of the system products based on 802.11n, designed to make maximum use of the RF domain, do little in this regard 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. Smart Wi-Fi adds a new dimension in controlling the impact of RF changes in real time - antenna adaptation.
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 Wireless Smart Wi-Fi technology combines 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 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.
