Exemplary embodiments include a communication system comprising a portal between radio-frequency propagation environments; one or more of interface points disposed in the plurality of propagation environment and configured to communicate with each other via the portal; and one or more access points disposed in one of the propagation environments, at least a portion being configured to communicate with a particular interface point. Other embodiments include apparatus for communicating across radio-frequency propagation environments comprising at least one antenna array, a computer arrangement, and a non-transitory, computer-readable medium comprising computer-executable instructions that configure an adaptive antenna array to receive expected signals from a device or system disposed in a first propagation environment and to reject interfering signals originating in the same environment; and transmit the received expected signals to a compatible apparatus in a second propagation environment via a portal that is relatively permeable with respect to a particular frequency.