Several vendors have released dual 5GHz radio access points and are starting to communicate their "benefits" for the campus. On paper this might sound like a good idea but we see some real challenges. For one (apart from the comprehensive RF related arguments about frequency separation and filtering needed between the radios) a dual 5GHz Access Point gives you far less control with RF tuning. If the argument is that dual 5GHz radios gives you double the capacity per access point then you can deploy fewer access points to support the same client count but today we deploy for high density with low TX power and low data rates disabled so the Wi-Fi "cell size" is much smaller than it used to be. In order to get consistent coverage across the campus you need access points in many locations. I can't simply expect to have a dual 5GHz radio access point to cover twice the area as a single 5GHz radio. Even then if I were able to deploy each dual 5GHz radio access point with the ideal RF settings (channel, power etc.) I start to run into channel reuse issues much sooner than I do with single 5GHz radio access points. Being able to tune the power levels, data rates and other RF related parameters in a typical high density single 5GHz radio deployments gives much greater control than in a dual 5GHz radio deployment. It is not that we have not explored this concept at a R&D level, we have. As I mentioned at the start of this post it does seem like a good idea on paper but we do not see the practical benefits in the real world.
Recently we released a blog with detailed tests results of the dual 5GHz Cisco access points compared to the AP-315. You can see the blog here :
http://community.arubanetworks.com/t5/Technology-Blog/Does-the-Dual-5GHz-Story-Stand/ba-p/271720
I would be keen to hear your thoughts about dual 5GHz access points.
Mark