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Is 802.11n Right for You?

The debate over the readiness of 802.11n and whether businesses should adopt or wait is nothing new. Remember when Ethernet was too unpredictable to displace ATM? IP VPNs too unreliable for critical business data? The adoption rate of new technologies is commensurate with the benefits they deliver. 802.11n offers significant performance improvements over existing standards. Still, for most, the benefits must be evaluated in combination with longevity. In other words, few want to deploy a technology that may soon be obsolete -no matter how great the benefit.802.11n can deliver both performance and longevity. Illustrating market support, the Wi-Fi Alliance has certified over 180 products as 802.11n draft 2.0. Still, the draft status of the standard continues to beg the question of whether the technology is ready. The definition of”standard” includes consistency and interoperability -which are more a function of Wi-Fi certification than IEEE specification. Consider briefly the relationship of the original 802.11b to Wi-Fi, 802.11i to WPA2 and 802.11e to WMM. Businesses don’t deploy an IEEE specification; rather, a standard that guarantees interoperability. The same rings true for 802.11n. While not yet ratified, the 802.11n draft 2.0 has already become a de facto standard thanks to Wi-Fi certification and product development momentum. Cisco customers are putting this new technology to work today. A large apparel retailer is improving the quality of its warehouse voice-over-wireless implementation by deploying 802.11n. MIMO has improved the call quality of the company’s Cisco wireless IP phones by increasing network reliability and coverage predictability. A large U.S. hospital is deploying 802.11n to ensure consistent connectivity for synchronous patient care applications deployed to mobile computer carts. Without 802.11n, mobile carts were losing connectivity due to coverage holes caused by interference and multipath. Finally, Duke and Western Michigan universities are-deploying 802.11n across campus to support a growing diversity of client devices. Technology shifts are gradual events that generally take years. With the Wi-Fi Alliance assuring longevity, the adoption timeframes should be determined purely on business need. Assured of investment protection and the performance required for the truly mobile experience, businesses can adopt 802.11n with confidence today.

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6 Comments.


  1. Chris Kozup

    Duke, thanks for blogging with us.802.11n is a new standard that requires completely different silicon and radios from existing 802.11a/b/g access points. As such, existing access points cannot be upgraded to support 802.11n. This is not a Cisco issue, rather something that affects the entire industry.Having said that, existing 802.11a/b/g access points can coexist seamlessly with emerging 802.11n access points with both being supported on the same WLAN controller.Certain modules of the Cisco Catalyst 6500 and 4500 series switches will support Cisco Enhanced PoE to provide greater power for the Aironet 1250 Series AP.

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  2. Will The Aironet 1130AG Series be supported for 802.11n?If not, this will really impose a problem for us, to have to invest agian in new technologies (being obsolete in 3-4 uyears again!?). Will existing modules on Cisco 650x and 45xx series be able to handle new power stnadards needed for 802.11n? THe impact on network infrastructure might be huge!

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  3. Chris Kozup

    Thanks for your comments to the Mobility blog. Cisco has long delivered Power over Ethernet across a variety of switching platforms. Currently, the industry is settled on the 802.3af standard which specifies 12.95 watts to the device at the end of the cable. Current 802.11n solutions require greater than this. Cisco has increased the power budget on a series of Catalyst switches to meet the needs of the Aironet 1250 Series access points. This is done over the same cable, over existing pairs and does not require any change in cable plant. Cisco has increased the power output per switch port. Because there is no standard for this (remember, 802.3af only specifies up to 12.95 watts), Cisco is using CDP (Cisco Discovery Protocol) to handle the power negotiation between the AP and switch port. Cisco is a full supporter of the 802.3at PoE standard, which is the next revision of PoE. However, this standard remains a draft and as such, there are no products available in the market. Cisco will fully support 802.3at as it becomes available. Until this solution is available, Cisco will work to simplify deployment of 802.11n by innovating to solve customer problems.

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  4. Yes, how does it work? Cisco is vague about the details of their 802.11n PoE solution.One can only assume something proprietary.

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  5. So how does it work? How is the enhanced power being transmitted? There are no spare pair”” on 10/100/1000 switches so are you just sending more power over the data pair? I can’t imagine you are throttling back the switch to accommodate more power on so called spare pair as that would negate the advantage of 11n.”

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  6. Regarding the coverage holes causing inconsistent connectivity, 802.11n access points seem to increase the range by as much as a factor of 3x as compared to 802.11a/b/g. I came across a WLAN Coverage Estimator that gives a visual mapping of the coverage of different AP types.Does this mean, it will require fewer access points when deploying 802.11n for the same area?”

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