Each of a plurality of network nodes in an ad hoc mesh network utilizes a data communication device that includes a two-way communications component, comprising a first receiver and transmitter, and a second receiver. The second receiver activates the communications component from a dormant state when it receives a broadcast including a wake-up identifier of the communication device. A method of activating and deactivating a mesh network includes, first, transmitting a broadcast that includes a wake-up identifier such that each second receiver of each communication device identified by the wake-up identifier, upon receipt, activates the communications component of the communication device, which then engages in mesh networking communications, and, second, transmitting a second broadcast including a second identifier such that the communications component of each communication device identified by the second identifier, upon receipt, will cease its mesh networking communications and will return to the dormant state.