With a single wireless access point, you can move about with a laptop and still be connected to the same network. The situation gets more complicated when there is more than one access point.
As you move about you are doing what is called roaming and when you lose your connection you need to reestablish a new connection. As with bridging, roaming isn’t always well implemented in access points for the consumer market.
A standard called the Inter Access Point Protocol (IAPP) for wireless roaming for 802.11f was published by the IEEE task group, but it may be some time before you see this feature implemented.
First we need to see 802.11f devices, and then there has to be a demonstrated demand for roaming in the consumer marketplace—something that might never happen.
Most home and small business users don’t have multiple domains and thus don’t require roaming. There’s another situation where you would want to install multiple access points to increase throughput.
Consider a small design company where large files are transferred by several workers. To better serve this group, multiple access points are installed to overlaps so that the different clients could connect to different access points and thus balance the load of traffic among them.
Load balancing isn’t a feature you’ll find on consumer devices, and it’s difficult to implement because consumer devices lock onto the strongest signal they find. A load balancing solution requires the software control to select the access point that has the largest bandwidth available instead.