The document discusses the advantages of Wideband Multimode Fiber (WBMMF) for data centers, enabling high data rates (40g and 100g) using fewer fibers through Short Wavelength Division Multiplexing (SWDM). WBMMF supports multiple wavelengths, allowing significant reduction in fiber count and simplified cable management compared to traditional multimode fiber systems. It is designed to meet the increasing demands for cost-effective, high-bandwidth connectivity while remaining compatible with existing applications.

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Fiberstore (FS.COM) | WBMMF – Next Generation Duplex Multimode Fiber in the Data Center
Enterprise data center and cloud operators use multimode fiber for most of their deployments
because it offers the lowest cost means of transporting high data rates for distances aligned with
the needs of these environments. The connections typically run at 10G over a duplex multimode
fiber pair—one transmit (Tx) fiber and one receive (Rx) fiber. Upgrading to 40G and 100G using
MMF has traditionally required the use of parallel ribbons of fiber. While parallel transmission is
simple and effective, continuation of this trend drives higher cost into the cabling system. However,
a new generation of multimode fiber called WBMMF (wideband multimode fiber) is on the way,
which can enable transmission of 40G or 100G over a single pair of fibers rather than the four or ten
pairs used today. Now, let’s get close to WBMMF.
What Is Wideband Multimode Fiber?
WBMMF is a new multimode fiber type under development that will extend the ability of
conventional OM4 multimode fiber to support multiple wavelengths. Unlike traditional multimode
fiber, which supports transmission at the single wavelength of 850 nm, WBMMF will support traffic
over a range of wavelengths from 850 to 950 nm. This capability will enable multiple lanes of traffic
over the same strand of fiber to transmit 40G and 100G over a single pair of fibers and to drastically
increase the capacity of parallel-fiber infrastructure, opening the door to 4-pair 400GE and terabit
applications. Multimode fiber continues to provide the most cost-effective platform for high
bandwidth connectivity in the data center, and with the launch of the WBMMF solution, that
platform has been extended to support higher speeds with fewer fibers and at greater distances.
WBMMF – Next
Generation Duplex
Multimode Fiber in the
Data Center

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Fiberstore (FS.COM) | WBMMF – Next Generation Duplex Multimode Fiber in the Data Center
What Is the Technology Behind WBMMF?
WBMMF uses short wavelength division multiplexing (SWDM) to significantly increase its
transmission capacity by four times. WDM technology is well known for its use in single-mode
transmission, but has only recently been adapted for use with vertical cavity surface-emitting lasers
(VCSELs), which have been proven in high-speed optical communications and are widely deployed in
10G interconnection applications. SWDM multiplexes different wavelengths onto duplex MMF
utilizing WDM VCSEL technology. By simultaneously transmitting four VCSELs, each operating at a
slightly different wavelength, a single pair WBMMF can reliably transfer 40G (4x10G) or 100G
(4x25G). The use of SWDM then enables WBMMF to maintain the cost advantage of multimode
fiber systems over single-mode fiber in short links and greatly increases the total link capacity in a
multimode fiber link.
Why Does WBMMF Make Sense?
In order to increase transmission speeds up to 10G or 25G, transceiver vendors simply increased the
speed of their devices. When 40G and 100G standards were developed, transmission schemes that
used parallel fibers were introduced. This increase in fiber count provided a simple solution to
limitations of the technology available at the time. It was accepted in the industry and allowed
multimode links to maintain a low cost advantage. However, the fiber count increase was not
without issues. At some point, simply increasing the number of fibers for each new speed became
unreasonable, in part because the cable management of parallel fiber solutions, combined with the
increasing number of links in a data center, becomes very challenging. Please see the picture below.
Usually, 40G is implemented using eight of the twelve fibers in an MPO connector. Four of these
eight fibers are used to transmit while the other four are used to receive. Each Tx/Rx pair is
operating at 10G. But if we use WDMMF, two fibers are enough. Each Tx/Rx pair can transmit 40G
by simultaneously transmitting four different wavelengths. This enables at least a four-fold
reduction in the number of fibers for a given data rate, which provides a cost-effective cabling
solution for data center.

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Fiberstore (FS.COM) | WBMMF – Next Generation Duplex Multimode Fiber in the Data Center
Conclusion
WBMMF is born at the right moment to meet the challenges associated with escalating data rates
and the ongoing need to build cost-effective infrastructure. Besides, WBMMF will support existing
OM4 applications to the same link distance. Optimized to support wavelengths in the 850 nm to 950
nm range to take advantage of SWDM, WBMMF ensures not only more efficient support for future
applications to useful distances, but also complete compatibility with legacy applications, making it
an ideal universal medium that supports not only the applications of the present, but also those of
the future.

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Fiberstore (FS.COM) | WBMMF – Next Generation Duplex Multimode Fiber in the Data Center
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Notice: This document is for informational purposes only and does not set forth any warranty, expressed or
implied, concerning any equipment, equipment features, or service offered or to be offered by Fiberstore.
Fiberstore reserves the right to make changes to this document at any time, without notice, and assumes no
responsibility for its use. This information document describes features that may not be currently available.
Contact a Fiberstore sales team for information on feature and product availability.
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