A subsea optical communication network includes branch systems whereby transponders may be connected to trunk fibers carrying data to and from the transponders, e.g., to and from shore. Trunk nodes split transponder receive signals off the trunk and couple transponder transmit signals onto the trunk. Each trunk node also removes a wavelength/channel from the trunk signal to compensate for the wavelength being added with transponder data. Removed wavelengths may be selected from idler wavelengths, e.g., empty channels or noise, or previously dropped transponder wavelengths. Branch signals may be single wavelength in either direction, allowing the use of low-bandwidth repeaters, and the same wavelength may be used in both directions. Branch signals may alternatively contain plural wavelengths that load a standard wide-bandwidth commercial repeater, where an optical add drop multiplexer is used to select the wavelength of interest to the transponder after the repeater.
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