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What Difference between OS1 And OS2 Single-Mode Fiber Cables?

Views: 14     Author: celeste     Publish Time: 2024-03-01      Origin: Site

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1. What is OS1 fiber cables?

2. Applications of OS1 Fiber Cable

3. What are OS2 Fiber Cables?

4. Applications of OS2 Fiber Cable

5. OS1 fiber cables vs. OS2 fiber cables

6. How do you choose fiber cables between OS1 and OS2?

7. Why Opt for OS2 Over OS1 Fiber?

8. Conclusion


OS1 Vs OS2 cable

In the fast-paced world of networking, the choice of fiber optic cables plays a crucial role in determining the efficiency and reliability of data transmission. Among the various options available, OS1 and OS2 fiber cables stand out as popular choices for different applications. Understanding the distinctions between these two cables is essential for making informed decisions when setting up network infrastructures.

1.What is OS1 fiber cables?

Single-mode OS1 is an indoor tight-buffered fiber, specifically a 900-micron multi-fiber cable, where the fibers are tightly enclosed in a sheath made of Nylon, Hytrel, or PVC material. An OS1 cable can also be a micro-core Low Smoke Zero Halogen indoor cable, comprising 250-micron fibers tightly enclosed in a cable with aramid strengthening yarn and a Low Smoke Zero Halogen jacket.

2.Applications of OS1 Fiber Cable

OS1 cables, known for their low signal loss and precision, are widely used in various industries and environments to facilitate high-speed data transmission within limited geographic areas. They are extensively employed in LANs, telecommunication networks, data center connections, campus networks, building-to-building connections, security systems, healthcare IT infrastructure, industrial control systems, educational institutions, broadcasting and media, government networks, and financial institutions. OS1 cables cover a wide range of industries and environments, providing reliable and efficient solutions for high-performance networking needs.

3.What are OS2 Fiber Cables?

Single-mode cable OS2 is designed as an outdoor loose-tube optical fiber cable, specifically suited for outdoor applications where the installation exerts minimal stress on the optical fibers. For example, a multi-fiber cable with a 250-micron coating, allowing for movement within an enclosure or tube, is categorized as OS2.

Moreover, both OS1 and OS2 cable variants may encompass cables crafted from B6_A fiber, commonly known as bend-insensitive single-mode optical fiber, or ITU specification G657A2, which is compatible with B1.3 optical fiber.

OS2 cabled optical fiber proves well-suited for outdoor and versatile loose-tube solutions, catering to external facilities and a majority of backhaul networks.

4.Applications of OS2 Fiber Cable

OS2 fiber cables have a wide range of applications, catering to scenarios where long-distance, high bandwidth, and low signal loss are crucial requirements. OS2 Single-Mode Fiber (SMF) cables find extensive use in WANs, inter-city and long-distance connections, backbone networks, high-speed internet service providers, telecommunication backbones, Metropolitan Area Networks (MANs), government and military communications, research and education networks, healthcare backbones, the oil and gas industry, submarine communication cables, and aerospace communication. The reliability and performance of OS2 fiber cables make them an indispensable part of various industries and critical infrastructure projects.

fiber cables

5.OS1 fiber cables vs. OS2 fiber cables


OS1 cables adhere to ITU-T G.652 specifications, encompassing ITU-T G.652A and ITU-T G.652B standards (conventional), as well as ITU-T G.652C and G.652D standards (low-water-peak). Conversely, OS2 fiber cables strictly comply with ITU-T G.652C or ITU-T G.652D standards, specifically designed for low-water-peak fibers often utilized in CWDM (Coarse Wavelength Division Multiplexing) applications. A novel standard—G.657.A1 standard—has been released for bend-insensitive SMF cables to optimize performance and cost balance, with some OS2 SMF fiber cables aligning with this standard.

Fiber Cable Construction

OS1 SMF fiber cables, ensconced in a robust polymer jacket, are suitable for tight-buffered indoor applications. In indoor settings, the jacketed fiber is typically enclosed, featuring a bundle of pliable fibrous polymer strength members such as aramid within a lightweight plastic cover, forming a straightforward cable. In contrast, OS2 fiber cables predominantly adopt a loose-tube construction, more apt for outdoor scenarios. Rigorous cable construction becomes imperative when deploying in challenging environments. OS2 SMF cables are helically laid into semi-rigid tubes, allowing the cable to stretch without elongating the fiber itself to safeguard it from tension.


OS1 cable experiences higher attenuation compared to OS2 fiber cable. Generally, OS1 cables exhibit a maximum attenuation of 1.0db/km for 1310nm and 1550nm, while OS2 maintains a lower numerical value of 0.4db/km for 1310nm and 1550nm. 

Consequently, the maximum transmission distance for OS1 SMF cable is limited to 10 km, whereas OS2 SMF cable can achieve distances of up to 200 km. Both OS1 and OS2 single-mode fibers support speeds of 1 to 10GbE with varying transmission distances.

Furthermore, OS2 single-mode fiber optic cables are applicable for 40G/100G Ethernet connections.


OS1 cables are Usually relatively cheap and suitable for general short-distance communication needs.OS2 cable is usually relatively expensive and more suitable for long-distance communication scenarios with higher performance requirements.


OS1 single-mode fiber optic cable security concerns are relatively low.OS2 Cables are mainly used for more critical long-distance transmission, their security requirements may be higher, and more security measures need to be taken.

Installation and maintenance

OS1 cables are installed and maintained, which is relatively simple.Installation and maintenance of OS2 cables may require more specialized techniques and equipment.

OS1 Vs OS2 fiber cable

The specification table below elucidates the distinctions between OS1 and OS2.




ITU-T G.652A/B/C/D

ITU-T G.652C/G.657.A1 (part)

Cable construction

Tight buffer

Loose Tube













6.How do you choose fiber cables between OS1 and OS2?

When deciding between OS1 and OS2 single-mode fiber cables, it is imperative to clarify whether these cables are intended for long-haul transmissions. Select the appropriate cables based on your specific link length requirements.

Consequently, OS1 cables suit indoor application demands.OS2 fiber cables are better suited for outdoor and universal loose-tube solutions, encompassing external plants and most backhaul networks.

OS1 SMF fiber cables find application in indoor network infrastructures, primarily deployed in internal building/campus networks, telecommunication exchanges, and data centers' internal cabling.  When outdoor network infrastructure is essential, OS2 is the preferred choice.

7.Why Opt for OS2 Over OS1 Fiber?

After comparing the two fiber cables, it can be concluded that the OS2 cable, with better performance and fewer losses, is more suitable for long-haul transmissions. Considering this, why not adopt optimal OS2 cable solutions to enhance performance for today's high-speed data networks?

Historically, OS1 SMF cable was the sole standard for single-mode fiber, with a maximum link length for campus cabling around 10 km. However, it no longer meets the growing demand for longer link lengths. OS2 single-mode fiber optic cables are ideal for connecting 1G/10G/40G/100G Ethernet connections, meeting high-performance requirements over extended distances. Consequently, an increasing number of vendors are inclined to offer solutions with OS2 SMF cables for modern network applications.

LC single mode fiber cables


In the realm of fiber optic cables, the selection between OS1 and OS2 hinges on a multitude of factors, with each presenting distinctive advantages. OS1 is particularly proficient in short-distance applications, whereas OS2 demonstrates its prowess in long-distance scenarios. By comprehending these differences and carefully assessing project requirements, individuals can make well-informed decisions to establish a resilient and efficient network infrastructure.


Q1: Is OS2 better than OS1?

A1: The superiority of OS1 or OS2 depends on your specific needs. OS1 is ideal for short-distance applications, while OS2 excels in long-distance scenarios. Choose based on the project requirements.

Q2: How do i know if my fiber is OS1 or OS2?

A2: Check the cable markings or documentation. OS1 and OS2 cables are labeled, and the information should be available in product specifications. You can also consult with the manufacturer or supplier.

Q3: What is the maximum distance covered by OS1 fiber cable?

A3: OS1 fiber cable is suitable for shorter distances, typically a few kilometers. Beyond that, signal loss may occur. It's crucial to consider your project's distance requirements when choosing the cable type.

Q4: Can OS2 fiber cable be used for short-distance connections?

A4: Yes, OS2 fiber cable can be used for short distances. However, it's designed for longer-range applications, so it might be a costlier option for short-distance connections compared to OS1.

Q5: Are there specific environments where OS1 is more suitable than OS2?

A5: Yes, OS1 is suitable for indoor environments like offices and data centers, where shorter connections are common. OS2, on the other hand, is more resilient and suitable for harsher outdoor or challenging conditions.

Q6: How do I ensure proper maintenance of OS1 and OS2 fiber cables?

A6: Follow industry best practices for installation, conduct regular checks for damage, and ensure cleanliness. Adhere to recommended maintenance schedules and promptly address any issues to ensure optimal performance.

Q7: What are the cost considerations when choosing between OS1 and OS2?

A7: OS1 is generally more cost-effective for shorter distances, making it suitable for projects with budget constraints. OS2, while offering superior performance for longer distances, may come at a higher cost. Consider your project's budget and performance requirements for the best choice.

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