Cost-Efficiency of Multimode Fibers in 800G Deployments

Data centers are rapidly expanding, and the demand for high-speed 100/400/800G connectivity is continuously growing. Fiber optic cables serve as the backbone for achieving fast data transmission. Among them, multimode optical fibers (MMF) are a cost-effective and practical solution for short-distance applications in data centers, playing a crucial role in achieving 800G speeds. This article explores the cost-efficiency of multimode fibers in 800G networks and the technology that supports their implementation in modern data centers.

Multimode Fiber is Cost-effective in Short Transmissions

Fiber optical fibers offer unmatched speed, reliability, and bandwidth capabilities, which are crucial for 100/400/800G high-speed, low-latency data center connections. While there are various types of optical fibers, multimode fiber cables are particularly well-suited for short-distance applications. They are designed to carry multiple light modes simultaneously, enabling high-speed data transmission over relatively short distances. Moreover, the multimode fibers in 800G provide the following advantages:

Economical Multimode Optical Components

One of the primary benefits of multimode optical fibers is their cost-efficiency. Compared to single-mode fibers, the installation and maintenance costs of multimode fiber systems are considerably lower. The optical components required for MMF, such as transceivers, are also more affordable. One OSFP 800G SR8 for MMF at FS costs $799 dollars, while OSFP 800G DR8 for SMF requires $1199. Therefore, in this respect, multimode fiber cabling is a more cost-effective solution for data centers that need to support high-speed connections across short distances.

Sufficient Transmission Distances for Data Centers

Someone may question that, the prices vary between the 800G SR8 and DR8 modules due to their different transmission distances. But note that multimode fibers can cover most inter-connection distances in data centers.

According to Corning analysis, for enterprise data centers, the average link length is 49 meters, with over 90% of links being shorter than 100 meters. And for 800G links, using MTP®-12 OM4 jumpers can support up to 100 meters via OSFP-SR8-800G-FL, Flat Top, which is already enough for data center connections. This means that multimode fibers can support high-speed, high-bandwidth data transmission within the space constraints of a typical data center.

More Energy-efficient Solutions

It's well known that multimode transceivers use vertical-cavity surface-emitting lasers (VCSEL) that operate at a wavelength of 850nm. Using VCSEL transceivers with multimode fibers for data transmission and reception consumes over 20% less power compared to single-mode transceiver-based solutions (data comes from Corning research), and it also reduces greenhouse gas emissions. The combination of high-speed and low power consumption makes multimode fiber solutions more advantageous for deployment in short-distance links between switches within data centers.

Commercial 800G Modules Pave the Way for Multimode Fiber

Multimode VCSEL transceivers currently offer a maximum rate of 800G. Utilizing PAM-4 modulation, they achieve a single-channel rate of 100Gb/s, operating at a wavelength of 850nm. Compared to the previous 400G version (SR8, with a single-channel rate of 50Gb/s), the rate has doubled. As the single-channel rate increases to 100Gb/s, the transmission distance will be reduced to varying degrees due to the bandwidth limitations of multimode fiber at 850nm. OM3 multimode fiber supports a transmission distance of 70 meters, while OM4 multimode fiber can reach 100 meters, still meeting the short-distance connectivity needs of most data centers.

Multimode Fiber Solutions in 800G Applications

To meet data centers' varying short-distance transmission needs, FS currently offers MTP® multimode fibers in 800G cabling solutions. Those OM3 and OM4 multimode fibers work with different modules for various transmission distances.

Both MTP®-12 and MTP®-16 multimode jumpers use APC (angled physical contact) polishing. APC multimode connectors minimize the impact of return loss in the cable channel, helping maintain a cleaner signal with less interference. This is essential for applications requiring high data rates, such as in modern 800G data centers. As a critical part of structured cabling, 12- and 16-fiber MTP® multimode fibers support multiple network generations while also helping minimize the impact of equipment change. For example, it supports 800G to 2x 400G, using the legacy MTP®-12 APC fiber.

Additionally, for users with transmission needs less than 100m, the above multimode fibers can support the vast majority of link lengths in their networks. While meeting transmission distance and 800G bandwidth requirements, FS multimode fiber solutions can ensure high-performance connectivity while maintaining cost-effectiveness. Looking ahead, FS plans to continue introducing 800G BiDi multimode solutions in the future, which can support longer transmission lengths via multimode fibers.