Described herein is a space based subsystem of a satellite, and methods for use therewith, for receiving an optical ISL beam from another satellite, and in dependence therein, producing a further optical ISL beam for transmission to a further satellite. Additionally, the subsystem can also produce RF service downlink beams for transmission to service terminals. The subsystem can include, inter alia, receiver optics, optical amplifiers, a WDM demultiplexer, beam splitters, a WDM multiplexer, and transmitter optics. In certain embodiments, because RF frequencies of a wavelength division multiplexed optical signal produced by the WDM multiplexer are within a same specified RF frequency range within which the satellite and the further satellite are configured to transmit RF service downlink beams, there is an elimination of any need for the satellite and further satellite to perform any frequency conversions when producing the RF service downlink beams in dependence on the optical ISL beams.