In a system and method of optical communication, optical signals are generated in multiple wavelength channels. Each optical signal is passively transported from an origination node of a network to a destination node. The destination node is determined by the signal wavelength. For at least some signals, the passive transport includes transport through a branch point of the network, such that the signal wavelength determines the output branch through which the signal is routed. In certain embodiments, signals are generated according to a schedule devised to substantially prevent the concurrent arrival, at the same destination node, of signals having the same wavelength but coming from different origination nodes.