A transmitter module for unidirectional communication with a receiver module and a method using the aforementioned. The transmitter module includes a carrier detection portion, a source processing portion coupled to the carrier detection portion and a source transmission portion coupled to the source processing portion. The source processing portion can receive and process an information signal to produce a processed information signal in a manner such that an appropriate carrier signal is modulated with the information signal. The appropriate carrier signal can be based on the detection signals communicated from the carrier detection portion. The source processing portion can further process the information signal in a manner such that the processed information signal is associable with at least one of a unique code and an indication signal. The indication signal is associable with absence of communication of the at least one communication signal in a communication medium.