Following up on Scott Ferguson's story on Cisco Systems' new enterprise Aironet 1140 802.11n access point from a few weeks ago, I had an interesting conversation with Cisco's senior manager of Mobility Solutions, Chris Kozup, about the new product line.
For me, the most interesting technology improvement with the Aironet 1140 is ClientLink, Cisco's take on beamforming. With beamforming, an optional component of the still-in-progress 802.11n standard, the AP will focus its antennas on a particular client to improve signal gain and performance.
With the Aironet 1140, Cisco implements beamforming in hardware, as Cisco developed new silicon for the task. Kozup claims that doing beamforming in silicon allows Cisco to focus the strength of the beam on a per packet basis, allowing the hardware to quickly and effectively switch focus between multiple clients attached to the same AP, even while using the same 2x3 transmit/receive chain and omnidirectional antennas.
The only other beamforming solution I've seen to date comes from Ruckus Wireless, which for several years has practiced beamforming techniques in software -- first with its 802.11g and then with its 802.11n APs -- directing the signal to clients via a specially designed array of direction antennas.
For Ruckus' take on the drawbacks of Cisco's hardware approach, look here.
Also of note from my chat with Kozup was Cisco's zeal for making it as easy as possible for existing Cisco Aironet customers to upgrade to 802.11n technology and the Aironet 1140.
First of all, the new AP promises to work with existing 802.3af POE (power over Ethernet), providing two full performance streams (two transmit x three receive) and dual-band support at less than 12.95 watts of power. So customers won't need to rip out their existing POE switches to deploy (noncrippled) 802.11n.
Cisco wants to take the simple upgrade a step further. Kozup also informed me that the Aironet 1140 was designed to fit in the same mounting brackets as legacy 802.11b Aironet APs, so wireless administrators only need to swap in the new AP in place of the old.
Implicit in this deployment scenario, however, is that Cisco intends to deliver these new APs as one-to-one replacements for the old 802.11g. The good news is that Cisco therefore promises no new site surveys are needed for deployment, but, on the other hand, customers will not necessarily see the benefits they expect from the increased range afforded by the new wireless standard.
When I questioned Kozup about this strategy, he emphasized that wireless implementers now need to focus their deployments on performance and not just coverage. Given that new generation wireless networks are now used for much more than simple e-mail and Web surfing, and are much more likely to carry a host of applications (including voice and possibly video), deploying a network simply to maximize coverage will not reap the full value of the network.