There are two main types of managed wireless networks—those that have client-controlled access, and those that have centrally-controlled access. In the former the individual wireless client embedded in the wireless mobile device makes its own decisions on which wireless access point to associate with. In the latter the wireless controller places the client on what it considers to be the appropriate wireless access point.

The client-determined access method generally works, except in situations where there are a lot of possible access points to attach to (in situations where there’s a high concentration of AP’s to build network capacity), in situations where there’s unusual topography, or in situations where clients are especially mobile.

You can then get bad events like RF ping-ponging (where clients bounce from wireless access point to wireless access point), RF fencing (where high-powered emitters like laptop PC’s block lower-powered emitters like mobile phones from wireless access), unacceptable or unworkable isochrynous—video and voice—traffic, and slow network response times caused by the overloading of some wireless access points. You can take special measures to minimize these woes—working harder, or you can assign a computer to handle it. That is, you can install a centrally-controlled access system. By far the best option for one of these is Meru Networks.

A controller-directed wireless access system negates those bad events by controlling where the individual clients get wireless access. The controller directs the client to less heavily-loaded access points, actively manages their association with the access points, provides the correct levels of service, and manages the handoffs for mobile clients. If you run a wireless network today you’re well aware of Channels One, Six and Eleven, and have carefully created a multi-channel network, tweaking channel assignments and access points to maximize coverage and minimize interference. Kind of like this:

All of this is unnecessary with a controller-directed system—you just install access points, put all of them on the same channel, and have the controller actively handle the access point assignments and the roaming between access points. Kind of like this:

Benefits? You have better service, particularly with mobile clients and those needing to do voice and video. You also can completely forget about doing pre-and-post installtion surveys. You use less access points for an equivalent network capacity level—about 30 percent less. And then if you do need to pack in access points to create high-capacity wireless zones you can. In a more conventional micro-cell system that’s just not possible.