Multimode fiber was the long‑standing standard in traditional AV installations. It was affordable, familiar to technicians, and more than sufficient for short distances. However, AV networks have changed dramatically in a relatively short period of time. The rise of AV over IP, ST 2110‑based infrastructures, and ever‑increasing bandwidth requirements has fundamentally shifted the demands placed on cabling.
As a result, single‑mode fiber (OS2) is increasingly becoming the logical and future‑proof choice. Not because multimode no longer has a role, but because its limitations become visible much sooner in modern AV and broadcast environments.
Modern AV over IP demands higher bandwidth and longer distances
AV‑over‑IP workflows are processing ever‑greater volumes of data. Examples include 4K/60 uncompressed video streams, 8K signals and high‑frame‑rate productions, 25G and 100G uplinks between core, spine, and edge switches, and remote production over campus or data‑center connections.
Single‑mode fiber supports these speeds over long distances, ranging from hundreds of meters to many kilometers. This provides significantly more design freedom than multimode fiber, especially in environments where infrastructure spans multiple rooms, studios, technical areas, or even entire buildings.
With multimode fiber, distance and scalability become constraints much more quickly. In modern AV and broadcast networks, this can easily turn into an unnecessary bottleneck.
A single clear standard simplifies design and management
Multimode fiber exists in multiple variants: OM1, OM2, OM3, OM4, and OM5. In existing buildings, these are often mixed in practice. This can result in uncertainty about supported speeds, inconsistencies between floors or spaces, a higher risk of mismatches between optics and cabling, and more complex troubleshooting.
Single‑mode simplifies this significantly. In practice, OS2 is the dominant standard. This leads to greater uniformity in network design, more predictable management, and fewer risks during future expansions. These advantages are especially valuable in AV environments with long life cycles, such as theaters, conference centers, and broadcast facilities.
Single‑mode optics have become far more accessible
For many years, cost was the primary argument against single‑mode fiber. That situation has changed significantly. Due to widespread adoption in data centers, cloud infrastructures, and telecom networks, single‑mode optics such as LR, FR, and ER modules have become much more affordable.
At 25G and 100G speeds in particular, the price difference compared to multimode is often minimal, and in some cases single‑mode is even more cost‑effective. This is especially true when multimode solutions rely on MPO‑based SR4 implementations.
When evaluated over the total cost of ownership rather than just initial purchase price, single‑mode often turns out to be the more economical option—particularly when future upgrades, design and management complexity, standardization with IT, and predictability are taken into account.
Single‑mode aligns naturally with ST 2110 and broadcast infrastructures
In modern broadcast and production environments, ST 2110 is increasingly used as the foundation for video, audio, and data transport over IP. Although the standard does not mandate a specific fiber type, many new facilities deliberately choose single‑mode fiber as their underlying infrastructure.
This choice is easy to justify. These environments typically require multiple parallel 4K or 8K feeds, spine‑leaf architectures with 25G to 100G links, integration with data‑center switching, longer physical distances, and redundant A/B networks without unnecessary limitations.
Single‑mode fiber fits these requirements naturally and makes it easier to build a stable, scalable, and uniform IP fabric with sufficient room for growth.
Fewer constraints in hybrid AV/IT networks
AV networks no longer exist in isolation. They increasingly share infrastructure with IT core switches, campus backbones, cloud connectivity, and remote production workflows.
In such converged environments, standardization becomes critical. When AV remains on multimode fiber while IT has already standardized on single‑mode, additional conversions, a wider variety of optics, and increased management complexity quickly emerge.
Single‑mode helps simplify this landscape by enabling a single fiber type, reducing design variation, and creating a more consistent network architecture.
At 40G, 100G, and beyond, single‑mode is often more practical
At higher speeds, multimode solutions frequently rely on parallel optics, which introduce stricter requirements for connector handling, polarity, and installation accuracy. This increases the risk of errors and places greater demands on documentation and maintenance.
Single‑mode fiber often offers a clearer and more manageable growth path. Duplex connections remain viable, distance margins are larger, and overall management tends to be simpler. For AV installations planning to grow toward 100G or beyond, this becomes a significant practical advantage.
Does multimode still have a role? Yes—but a more targeted one
Multimode fiber has not disappeared. It remains a sensible choice for short distances within a single room, existing infrastructures that will not be replaced in the near future, and environments where 1G or 10G will remain sufficient for many years.
However, for backbones, new builds, renovations, theaters, large venues, universities, production environments, and broadcast facilities, single‑mode fiber is increasingly becoming the most logical standard.
Conclusion
Anyone designing a modern AV‑over‑IP or broadcast network today would be well advised to seriously consider single‑mode fiber as the baseline. It supports higher speeds, longer distances, and a simpler, more consistent network design. Moreover, it aligns closely with the ongoing convergence of AV, IT, and broadcast infrastructures.
Multimode continues to work well in the right context. But for those looking to avoid future limitations and retain maximum design freedom, single‑mode fiber is becoming the preferred choice in an ever‑growing number of projects.
Eric Lindeman, NETGEAR ProAV Staff Systems Engineer Benelux
For more information about NETGEAR AV Switching, please contact the NETGEAR Pro AV Design Team via email: ProAVdesign@netgear.com
If you’d like to delve deeper into AV over IP switching, I invite you to check out our Online Academy via the link: https://academy.netgear.com/
On our training portal, you can find both AV and IT-related training courses. These courses are free to attend after registration, and at the end of each course, you can take an exam to earn a certificate.
