Gigabit and 10 Gigabit Cabling Technology - LAN Wiring - page 304

TABLE 12.9
10 Gigabit Ethernet Standards Physical Layers for Fiber

Standard Wavelength Mode Core/Cladding Range*

10GBaseSR 850 nm MM 50/125 µm 66-300 m

10GBaseSW 850 nm MM 50/125 µm 66-300 m

10GBaseLR 1310 nm SM 10/125 µm 10 km

10GBaseLW 1310 nm SM 10/125 µm 10 km

10GBaseEW 1550 nm SM 10/125 µm 30-40 km

10GBaseLX4 WDM (four MM 62.5/125 µm 300 m

wavelengths) MM 50/125 µm 240-300 m

SM 10/125 µm 10 km

* Range is dependent on modal bandwidth of the fiber that is used.

mode fiber, 62.5 µm and 50 µm, plus single-mode fiber. It accomplishes this feat by
splitting the nominal 10 Gb signal into four “lanes,” each of which is carried on a
different optical wavelength. At the other end, the signals on the four wavelengths
are detected and, in effect, combined to reconstitute the 10 Gbps signal. LX4 is the
hero to those of us who have existing fiber runs, most of which are multimode
installations, because it allows for the greatest multimode distance at 10 Gb. At 240
to 300 m, it is clearly suitable for 100 m horizontal runs, and it meets the criteria
for most backbone runs, as well.
IEEE networking standards actually cover 10 GigE operation for purposes
beyond the LAN. As you can see from the table, some operating modes extend 10
GigE well into the wide area (WAN). The “W” standards get into longer distances,
from 300 m to 30 km. In addition, IEEE 802.3ah covers a whole range of additional
standards to provide Ethernet in the First Mile (EFM). EFM has one new mode, pas-
sive optical, that offers exciting possibilities for putting fiber into every home and
business, much in the same way coaxial cable TV does today. All of the EFM tech-
nologies extend far beyond a mere one mile, to 10 or 20 km, but the “first mile”
term (or “last mile,” if you wish) is really a generic term that means from the car-
rier's distribution point (or central office) to the customer's premise. Regardless of
the terminology, EFM will soon be coming to a home near you.

10 Gigabit TIA Fiber Cabling Standards. The flip-side of the IEEE 10 Gigabit
Ethernet standards are a corresponding set of TIA-568-C standards that provide the
actual LAN wiring components to support such speeds. The fiber-optic cable stan-
dards for 10 Gb operation have actually been out for a while. However, the early
implementations did not allow 10 Gb operation to the nominal 300 m if you were