In a building environment, a distance associated with a building
automation device is determined as a function of an interval or an
inserted time delay between a wireless transmission of a signal and
wireless reception of another signal. For example, a two-way
communication is provided with an automatic interval or a desired time
delay inserted before responding to a received transmission. By using
two-way transmissions, the building automation devices may be free of
clock synchronization. Acoustic signals may be used in a building
environment to determine a distance. The building automation device may
also use radio frequency information for communicating with other
devices.