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Difference Between OS1 and OS2 Single Mode Fiber Cable


As we all know, multimode fiber is usually divided into OM1, OM2, OM3 and OM4. Then how about single mode fiber cable? In general, single mode fiber cable is categorized into OS1 and OS2 fiber. OS1 and OS2 are cabled single mode optical fiber specifications. In fact, there are many differences between OS1 vs OS2 single mode fiber. This text will make a comparison between OS1 vs OS2 and then give you a guide on how to choose the right fiber optic cable for your applications.

OS1 single mode fibers are compliant with ITU-T G.652A or ITU-T G.652B standards. Besides, the low-water-peak fibers defined by ITU-T G.652C and G.652D also come under OS1 single mode fibers. That is to say, OS1 is compliant with specifications of ITU-T G.652. However, OS2 single mode fibers are only compliant with ITU-T G.652C or ITU-T G.652D standards, which  means OS2 is explicitly applied to the low-water-peak fibers. These low-water-peak fibers are usually used for CWDM (Coarse Wavelength Division Multiplexing) applications.

OS1 vs OS2Besides the standards, the main difference between OS1 and OS2 single mode fiber is the cable construction. Typically, OS1 cabling is tight-buffered construction, which is usually used for indoor applications, such as campus or data center. Yet OS2 cabling is loose-tube design. Cable with this construction is appropriate for outdoor cases like street, underground and burial. For this reason, OS1 indoor fiber has greater loss per kilometer than OS2 outdoor fiber. In general, the maximum attenuation for OS1 is 1.0 db/km and for OS2 is 0.4db/km. As a result, the maximum transmission distance of OS1 single mode fiber is 2 km but the maximum transmission distance of OS2 single mode fiber can reach 5 km and is up to 10 km. Then for all these reasons, OS1 is much cheaper than OS2. There is point need to pay attention to is that both OS1 and OS2 single mode fibers over their distance will allow speeds of 1 to 10 gigabit Ethernet. All of these differences between OS1 and OS2 discussed above are listed in the table below. You can get a clear understanding from it.

Name OS1 OS2
Standards ITU-T G.652A/B/C/D ITU-T G.652C/D
Construction Tight buffered Loose tube
Application Indoor Outdoor
Attenuation 1.0db/km 0.4db/km
Distance 2 km 10 km
Price Low High

Learning about the differences between OS1 vs OS2 single mode fiber cable, then which cable should you choose? First, if you want to use for the indoor application, OS1 is better for you. However, if used for outdoor application, you should choose OS2. Second, there is no benefit to be gained in using OS2 cable if under 2 km. OS2 is best for distance over 2 km. Finally, you should note that OS1 is much cheaper than OS2. In order to save cost, if the OS1 is enough for your application there is no need to use OS2. Fiberstore offers OS1 and OS2 single mode fiber cable as well as all kinds of multimode fiber cable. It is your optimal selection.

Related Articles:

What are OM1, OM2, OM3 and OM4 multimode fiber?
Single Mode Fiber: How Much Do You Know?
What Kind of Single-mode Fiber Should You Choose?