and efficient buildings and data
centers increasingly rely on a state-of-the-art physical layer
infrastructure to support growing bandwidth needs over copper, fiber and wireless
technologies. When it comes to optical fiber transmission, singlemode fiber
often gets the headlines with high-speed
transmission records over long distances; however, multimode fiber is the workhorse media of local area network (LAN)
backbones and storage area networks (SAN) in buildings and data centers.
reason is because multimode fiber offers the lowest cost means of transporting
high data rates for the distances aligned with the needs of these environments.
We can expect multimode fiber’s dominance
in buildings and data centers to continue because of recent developments in
multimode technology and international standardization that will extend the
value proposition offered by multimode fiber for today’s and tomorrow’s
its original inclusion in the international
cabling standard ISO/IEC
11801, multimode fiber has evolved from supporting multi-megabit per second transmission using light
emitting diode (LED) light sources to being optimized for multi-gigabit
transmission using 850 nanometer (nm) vertical
cavity surface emitting lasers (VCSELs). With the introduction of laser
optimized multimode fiber in the late 1990s, a significant update to the
ISO/IEC 11801 standard included the addition of cabled optical multimode (OM) fiber categories—OM1, OM2 and OM3.
and OM2 were defined for legacy LED optimized fibers. OM3 was defined for multimode
fiber optimized for laser transmission at 850 nm. A few years later, an OM4
category was added, to recognize multimode fiber with more than double the
effective bandwidth at 850 nm, supporting
extended distances for gigabit and multi-gigabit applications.
significant update to the multimode fiber categories is currently under way with
the development of the third edition of ISO/IEC 11801 (expected for publication
next year). Due to the success and prevalence of 850 nm VCSELs in today’s
networks, the third edition will
“grandfather in” the LED optimized OM1 and OM2 fiber categories. They may
only be used for changes and additions to existing installations. As a result, OM3
will be the minimum requirement for new installations.
OM3 and OM4 fibers are increasingly being used in parallel fiber
infrastructures using MPO connectors. They support speeds up to 100 gigabit per
second (Gb/s) using multiple parallel VCSELs with standards in development to support up to 400 Gb/s using parallel
most significant optical fiber development in the third edition of ISO/IEC
11801 is the recent addition of a wideband
multimode fiber (WBMMF) category allowing simultaneous transmission of
at least four different wavelengths over each fiber, expanding per-fiber
capacity with support for shortwave
wavelength division multiplexing (SWDM). The new WBMMF category will be included in
the standard’s final draft to be circulated shortly. The naming of the new WBMMF
category will be selected by national votes. The choices proposed are OM4W, OM5 and OM5W.
of the name selected, one thing is clear: WBMMF
is set to widen the applications horizon for multimode fiber in connected and
efficient buildings and data centers worldwide.
you considered WBMMF to help make your building or data center become connected