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Multimode Fiber Links for 800 Gb/s and 1.6 Tb/s Networks

Speaker Bio: G. Mabud Choudhury, Standards Manager, OFS

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Abstract: In this presentation, G. Mabud Choudhury of OFS presents his technical paper titled, “Multimode Fiber Links for 800 Gb/s and 1.6 Tb/s Networks”. This paper features a study of multimode solutions that are critical to supporting the demand for higher network traffic and faster access methods. Market conditions such as Artificial Intelligence, Machine Learning, and Cloud Infrastructure are driving the demand for higher speeds and capacities. Join us for this Technical Paper Webinar to learn how multimode fibre is adapting to enable increased Ethernet and Fibre Channel speeds.

With the ever growing need for bandwidth in the industry, IEEE 802.3 has started to define 800 Gb/s and 1.6 Tb/s Ethernet. For multiple generations of standards, technology drivers, and market needs, Laser-Optimized Multimode Fiber (LOMMF) coupled to Vertical-Cavity Surface-Emitting Lasers (VCSELs) links have been the dominant short reach, intra-data center optical solution. We present the latest trends for VCSEL-MMF links, that continue to be a widely deployed, cost-effective solution for some of the largest cloud hyperscale and most enterprise networks, as we enter the Terabit era.

Recently completed work in IEEE 802.3 Ethernet, INCITS T11 Fibre Channel and multi-source agreement (MSA) has introduced 400GbE (4 pairs/quad & 8 pairs/octal) and 64 Gb/s (1 pair/serial) Fibre Channel (GFC) MMF application standards and specifications based on 50 Gb/s electrical and optical signaling (50 Gb/s per wavelength, or 50 Gb/s lane) that will have major market presence. The IEEE standards and MSA specifications have also introduced multiple wavelength technologies, two-wavelength Bi-Directional (BiDi) and four-wavelength Shortwave Wavelength Division Multiplexing (SWDM4), that take advantage of optical bandwidth performance for wavelengths greater than 850 nm for MMF including OM5. Current active Ethernet, Fibre Channel, and MSA projects are developing MMF standards for 100GbE, 200GbE, 400GbE, 800GbE (1, 2, and 4 pairs), 128 Gb/s (1 pair, serial) GFC, and 800 Gb/s BiDi (4 pairs/quad, 2 wavelengths, 200 Gb/s per pair) and 1.6 Tb/s BiDi (8 pairs/octal, 2 wavelengths/pair, 200 Gb/s per pair) based on 100 Gb/s electrical and optical signaling (100 Gb/s per wavelength, or 100 Gb/s lane). There have also been updates in MMF standards for ANSI/TIA and ISO/IEC cabling standards and for TIA and IEC component standards, including for MM multi-pair MPO-12 and MPO-16 connectors, and for very small form factor single-pair SN/SAC and MDC connectors.

We summarize the latest updates on these standards and the underlying technology, market, and industry drivers. We then analyze, evaluate, and highlight the current trends for applications for cloud hyperscale and large enterprise markets. For hyperscale data centers, MMF links are being used both 4-pair/quad and 8-pair/octal architectures, for established Top of Rack (ToR) switch to server and switch to switch architectures with up to 100 m MMF (OM4) reach, but additionally for ToR elimination architecture with fiber to the machine (compute/storage/machine learning/artificial intelligence clusters) limited to up to 50 m MMF (OM4) for lower cost, lower power consumption and lower latency with data rates up to 400 Gb/s and 800 Gb/s. Large enterprise data centers remain an important segment of the market, with those data centers now transformed to support cloud applications utilizing private, public, and hybrid cloud approaches. Data rates from 10 Gb/s to 100 Gb/s remain widely utilized in enterprise networks, but the industry investment in Terabit MMF solutions underscores the long-term value proposition of VCSEL-MMF links, with future-proofing to speeds up to 1.6Tb/s, especially with OM5 fiber cabling infrastructure that is optimized for multi-wavelength technologies that allow higher data rates with longer reaches over fewer fiber pairs.

Our evaluation of the future of MMF-VCSEL links also briefly reviews emerging low-power, low-latency linear architecture applications in OIF and T11/Fibre Channel. We also survey next generation high-density multicore MMF development, and 200 Gb/s signaling or 200G VCSEL research literature. Our key conclusion is that the range of markets, technologies, standards, and customer needs continue to make VCSEL-MMF links a widely deployed, cost-effective, low-power, low-latency, high-density solution for high-speed short-reach applications both now and in the Terabit future.

About the Presenter: G. Mabud Choudhury is Standards Manager for OFS. He contributes to IEEE 802.3 Ethernet, INCITS T11 Fibre Channel, and IEC Fibre standards. He is Vice Chair for IEEE P802.3db 100 Gb/s, 200 Gb/s, and 400 Gb/s Short Reach Fiber Task Force. Mr. Choudhury has an MS degree in Mechanical Engineering from Massachusetts Institute of Technology, and a BS degree in Mechanical Engineering from Duke University. He holds 32 US patents.

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