The International Telecommunication Union (ITU) approved a standard for 40 Gbps optical transmission. The standard -- ITU-T Recommendation G.959.1 -- increases the capacity for optical interfaces from the present maximum of 10 Gbps to 40 Gbps. The new standard targets two un-amplified link distances: the first is for lengths up to 40 km and the second for up to 80 km. Such interfaces would use a C-band wavelength of 1535-1565 nm and single mode optical fiber, as specified in ITU-T G.652, G.653 and G.655. The standard uses Forward Error Correction...