OS, OM Fiber and What They Mean For Your Project

When determining what Proterial Cable America (PCA) fiber optic cable is right for your project, labels including OS1, OS2, OM1, OM2, OM3, OM4 and OM5 come up. But what do they mean?  

The labels are actually fiber optic cable designations that originated in the international ISO/IEC 11801 standard. Read on to learn more about the designations and how to determine which you need for your project. 

What is the International ISO/IEC 11801 Standard?

The ISO/IEC 11801 standard refers to the international requirements for designing, installing, and managing structured cabling systems in customer premises. This ensures that data communication systems, such as Ethernet and telephone networks, are efficiently supported worldwide. 

The standard outlines specifications for cable types, distances, connectors, and performance across various environments, including offices, data centers, and residential buildings. 

What is the Difference Between OS and OM Levels?

OS levels refer to Singlemode Optical Fiber cables, while OM Levels refer to Multimode Optical Fiber cables. 

Each of the designations is further broken down into subcategories to further identify different types of fiber optic cable. 

What are OS Fiber Cables? 

OS or Optical Singlemode Fiber, is labeled as either OS1 or OS2 depending on the makeup of the cable.  

  • OS1 applies to standard singlemode glass. It is usually tight-buffered and commonly used for indoor applications. 
  • OS2 applies to higher-performing, low-water peak singlemode glass. OS2 is a loose-tube design and can be used outdoors. 

What are OM Fiber Cables? 

OM or Optical Multimode Fiber, details the difference in the versions of multimode cables.  

  • OM1 indicates standard 62.5/125 micron multimode glass. This was an early multimode fiber using an LED as a light transmission source and is generally used for lower bandwidth applications (typically 100Mbps) and can travel up to 300 meters. 
  • OM2 is standard 50/125 micron glass. OM2 is similar to OM1 and still uses an LED as a light transmission source but can handle higher bandwidth uses (1,000Mbps) and can travel up to 600 meters. Both OM1 and OM2 are typically used to extend legacy private networks. 
  • OM3 is for enhanced 50/125 micron glass capable of supporting 10Gb Ethernet over distances up to 300 meters and with higher speeds at shorter distances. Unlike OM1 and OM2, OM3 is optimized with a laser light source (VCSEL) which makes it capable of supporting higher speeds. 
  • OM4 is for enhanced 50/125 micron glass cable capable of supporting 10Gb Ethernet over distances up to 550 meters. It can support 100G for up to 150 meters. OM4 is typically used for high-speed uses like data centers. OM3 and OM4 are used in parallel optic protocols which typically use four fibers in each direction to achieve higher speed links (BASE-8/16). 
  • OM5 is a little different. It’s also for 50/125 micron glass cable, and can transmit 40-100G but can send multiple signals on one fiber over four different wavelengths which means it can consolidate fiber use over a distance of 150 meters. 

How Do Fiber Optic Cables Work?

Data is transmitted as light pulses which travel through the glass core of the fiber. The cladding layer reflects the light so that we achieve total internal reflection (TIR) to avoid signal loss. In other words, the two glass layers of the fiber work together to cause the light to travel through the cable delivering information from one location to another. 

When Do I Use OS vs. OM?

OS levels are used whenever the project requires singlemode fiber optic cables. Singlemode cables have a narrower core and the light within follows only one path. This makes it ideal for traveling long distances while still delivering information successfully. It also has higher bandwidth but tends to be more expensive for the total system cost. 

OM levels are used for multimode Fiber Optic Cable use-cases. Multimode has a larger core with room for light to take multiple paths simultaneously, which can lead to issues like interference and signal loss. Multimode can’t travel as far but uses less heat and is cheaper for the total system cost. For this reason, multimode applications tend to be shorter than singlemode fibers.  

If planning to use multimode fiber optic cables on high speed premise networks, the industry standard has become OM3 or OM4 with LC Connectors, which are fiber optic connectors used commonly in data centers and in telecommunications because they are smaller, but still reliable and work with both singlemode and multimode fiber. 

Proterial Cable America Can Help You With Your Fiber Optic Project

PCA’s cable solutions team is ready to help you select the perfect fiber optic cable for your project. Whether planning a data center installation or upgrading a premise network, we have the experience and expertise to ensure that your project will be handled with reliable products manufactured with high-performance materials. 

Click here to check out our Fiber Optic Cable Catalog and contact us today so we can help you with your next project.