The Future of Multimode Cabling has a Name – OM5


In 2015, CommScope introduced an innovative new multimode fiber cable that, for the first time, optimized the performance of a range of wavelengths to enable optimal use of Wavelength Division Multiplexing (WDM) in data center and other short-reach environments. Known as wideband multimode fiber (WBMMF) cabling, it maximizes the ability of short-wavelength division multiplexing (SWDM) to deliver at least four times more traffic per strand of glass.
WDM puts several optical carrier signals onto a single fiber by using different wavelengths (i.e., colors) of laser light. For years, the capacity-multiplying benefit of WDM has resided almost exclusively with single-mode fiber transmission systems. As the predominant cable of choice for most data center applications is multimode fiber, the exceptional ability of WDM had been something data center managers can drool over but not actually use, until now.


Essentially, WBMMF cabling works by providing near-equivalent performance for a range of wavelengths spanning more than 100 nm. This contrast with existing OM3 and OM4 multimode fiber cabling that are optimized for operation of only a narrow range of wavelengths near 850 nm. Thus, WBMMF cabling enables optimal the use of at least four data streams on each fiber strand that can each operate, for example, at 10G (for 40G total) or 25G (for 100G total), and, anticipated in the not-too-distant future, 50G (for a total of 200G). These data streams are multiplexed and de-multiplexed completely within the SWDM transceivers, so no additional discrete components are required by the user.

Examples of such transceivers include “40G-BiDi”, a solution offered by Cisco and Foxconn Interconnect Technologies, and “40G-SWDM4” offered by Finisar and several switch manufacturers. In addition, a recent trade show has featured an interoperability demonstration of “100G-SWDM4” between two different transceiver manufacturers, Finisar and Lumentum.
Multimode Fiber has come a long way since its inception in the early 1980s. As with other transmission technologies, this was first deployed in long-haul networks. An early breakthrough project consisted of a blazing 45 Mb/s multimode fiber backbone running from Boston to Washington D.C. Now we are talking about supporting more than 1000 times higher data rates, but doing so over distances suited for inside buildings, all because multimode fiber systems continue to provide the lowest-cost optical connectivity.

Up until very recently, wideband multimode fiber (WBMMF) didn’t really have a definition – at least one that was widely recognized. Now, after 20 months, six face-to-face meetings, 13 teleconferences and three ballots, the Telecommunications Industry Association (TIA) published in June 2017 a new fiber specification that defines WBMMF. TIA-492AAAE is the first published specification for WBMMF and it defines the minimum requirements for laser-optimized modal bandwidth for operation in the vicinity of 850 nm to 950 nm. That means WBMMF cabling can support all legacy applications at least as well as OM4 cabling while also being optimized for existing and emerging SWDM applications.

Since its introduction, the structured cabling standards bodies have moved quickly to incorporate WBMMF into their recognized media. Already the TIA fiber specification is used to define a new wideband cabling performance level within the just-published American National Standards Institute ANSI/TIA 568.3-D structured cabling standard. By the end of 2016, TIA is expected to also approve standard 942-B which, among things, recognizes WBMMF for deployment in data centers. Also, in an international standards ballot that closed on October 5, OM5 was chosen by an overwhelming majority of nations as the official designation for cabling containing WBMMF in the upcoming 3rd edition of the International Organization for Standardization and the International Electrotechnical Commission structured cabling standard ISO/IEC 11801. And the Institute of Electrical and Electronics Engineers (IEEE) 802.3 that defines Ethernet has included WBMMF cabling in the list of media that supports the emerging 400GBASE-SR16 application. Inclusion of WBMMF cabling is also anticipated for the closely related 50GBASE-SR, 100GBASE-SR2 and 200GBASE-SR4 Ethernet applications. These are important milestones in standards progress for market acceptance of this new and revolutionary fiber cabling performance category. It now stands poised to extend the benefits of multimode fiber within connected and efficient buildings and within data centers worldwide.

The WBMMF solution is also compatible with legacy multimode applications, fibers and connectors. It will support all legacy applications at least as well as OM4 cabling, allowing it to provide a seamless migration path from the applications of today towards the higher rate SWDM applications of tomorrow. And, like today’s cabling, WBMMF can be deployed to support 2-fiber (duplex) channels, or parallel channels consisting of multiple pairs of fibers. In its parallel form, it can again multiply communications channel capacity. Considering that 200G per strand is anticipated, it is straight forward to see how a 4-pair parallel deployment of WBMMF could support 800G. That means WBMMF could support many generations of upgrades, from today’s commonly deployed 10G solutions to 25G, 40G, 50G, 100G, 200G, 400G, and 800G. Not bad for a medium that has been serving low-cost optical connectivity needs for so many years.

Now is the time to start thinking about how WBMMF figures into your migration strategy.

CommScope is proud to announce its LazrSPEED 550 OM5 is a fully compliant solution available now.