Location of one or more devices in a monitored environment based at least in part on data communications between a device and a communication array disposed relative to the monitored environment. The communication array may include a plurality of nodes, at least two of which may be in operative communication with a mobile device. The plurality of nodes may be synchronized to a common time base with communications over a packet-switched communication network (e.g., employing IP communications or the like). In turn, communications between nodes of known location and a device may be used to determine ranging values at least in part based on characteristics (e.g., time of flight) of the communication. As such, a location may be determined by, for example, multilateration of a plurality of ranging values.