free - space optical laser communication systems offer exceptionally wide - bandwidth , secure connections between platforms that cannot other wise be connected via physical means such as optical fiber or cable . however , fso links are subject to strong channel fading due to atmospheric turbulence and beam pointing errors , limiting practical performance and reliability . we have developed a fade - tolerant architecture based on forward error correcting codes combined with delayed , redundant , sub - channels . this redundancy is made feasible though dense wavelength division multiplexing and / or high - order m - ary modulation . experiments and simulations show that error - free communications is feasible even when faced with fades that are tens of milliseconds long . we describe plans for practical implementation of a complete system operating at 2 . 5 gbps .