An optically-switch data network includes an optical data bus, an optical wavelength bus, and multiple nodes connected by the optical data bus and the optical wavelength bus. A first node determines that it has communication information to transmit to a second node, and determines if a first subscription signal is present on the optical wavelength bus. The first subscription signal includes a target frequency. If the first subscription signal is not present on the optical wavelength bus, the first node injects an optical communication signal onto the optical data bus. The optical communication signal includes the communication information and a carrier wave. The carrier wave includes the target frequency. The second node receives the optical communication signal using the optical data bus. If the first subscription signal is present on the optical wavelength bus, injection of the optical communication signal onto the optical data bus is postponed.