Building a healthy Zigbee mesh: routers first, then battery devicesprocedure · unverified · Zigbee coverage and capacity come from routers. Add mains-powered routers before battery devices, pair end devices where they will live or through a nearby router, and know that some end devices never switch parents.
Zigbee basics: coordinator, routers, end devices and the meshguide · unverified · How a Zigbee network is built: exactly one coordinator, mains-powered routers that relay traffic, sleepy end devices that talk through one parent, and how this differs from Thread on the same radio.