A device is provided. The device includes: at least one antenna and a circuit. The circuit communicates with one or more agent devices through the at least one antenna, wherein the device and the one or more agent devices form a mesh network. The circuit periodically obtains a scan report from each agent device, and determines whether an OBSS (overlapping basic service set) airtime in the scan report of each agent device satisfies a first predetermined condition. In response to the OBSS airtime of each agent device satisfying the first predetermined condition, the circuit disables spatial reuse of each agent device by updating a plurality of spatial-reuse parameters for each agent device.