In a multi-AP WiFi environment — a mesh system, an office with multiple access points, or a home with a router and a range extender — the experience of moving between access points defines the quality of the whole system. A phone call that drops when you walk from the kitchen to the garden is not a signal problem; it is a roaming problem. Three 802.11 protocol amendments, operating together, are the mechanism that makes roaming fast enough to be invisible.

Two products solve the same problem — covering a large or multi-story home with consistent WiFi — from different engineering philosophies. Mesh systems optimize for installation convenience and seamless roaming. Multi-AP systems using wired backhaul optimize for raw performance and reliability. Which is better depends almost entirely on what your home’s infrastructure looks like and how much the installation process matters. The Single Router Problem A single router positioned in one location covers a sphere of radio energy that attenuates with distance and obstacle density.