Editing Gigabit Ethernet (section)

===1000BASE-BX10===
1000BASE-BX10 is capable of up to 10&nbsp;km over a single strand of [[single-mode fiber]], with a different wavelength going in each direction. The terminals on each side of the fiber are not equal, as the one transmitting downstream (from the center of the network to the outside) uses the 1490&nbsp;nm wavelength, and the one transmitting upstream uses the 1310&nbsp;nm wavelength. This is accomplished using a passive splitter prism inside each transceiver.

Other, non-standard higher-powered single-strand optics commonly known as "BiDi" (bi-directional) utilize wavelength pairs in the 1490/1550&nbsp;nm range, and are capable of reaching distances of 20, 40 and 80&nbsp;km, or greater depending on module cost, fiber path loss, splices, connectors and patch panels. Very long reach BiDi optics may use 1510/1590&nbsp;nm wavelength pairs.