From a performance standpoint, our testing revealed speed increases of four to six times what an 802.11a/g infrastructure can provide. And using an 802.11n access point for even legacy a/b/g clients delivered a measurable performance advantage thanks to MIMO (Multiple Input, Multiple Output) technology's ability to maintain high-bandwidth data rates for a larger portion of an AP's coverage area. For a/b/g voice over WLAN phones this greater reliability translates into higher quality calls and fewer dead spots.
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This isn't to say maximum performance won't increase as subsequent versions of 802.11n are endorsed by the Wi-Fi Alliance. But it does mitigate the risk that current devices will be incompatible with future revisions. The truth is, companies don't buy WLAN devices based on an IEEE standard, but on the Wi-Fi Alliance's endorsement of interoperability and the independent certification that 802.11n Draft 2.0 has received. In addition, Cisco is a member of Intel's more exhaustive "Connect with Centrino" interoperability testing program, which gives an added comfort level.Setting A 5GHz Strategy
The 5GHz frequency has been underutilized compared with the more popular 2.4GHz band, but with the advent of 802.11n that's poised to change. In the early days of WLANs, light user loads and a focus on maximizing coverage made the superior propagation characteristics of 2.4GHz a clear choice over 5GHz's more limited range. Now that those WLANs have grown from scattered hotspots to pervasive coverage blankets with many microcells supporting a multitude of users and high-bandwidth applications, the focus has shifted from coverage to capacity. And when you're talking capacity, nothing beats the massive amount of spectrum available in the 5GHz band, which encompasses 21 nonoverlapping channels when an AP implements full DFS2 (Dynamic Frequency Selection 2) support, compared with 2.4GHz's modest three nonoverlapping channels.