Deciphering the Passive Optical Splitter in PON Network

In the rapidly evolving landscape of optical networks, understanding the intricacies of Passive Optical Network (PON) components is essential. Among these, the passive optical splitter plays a pivotal role in optimizing signal distribution. This article delves into the significance, benefits and limitations of the passive optical splitter within the framework of PON.

Role of Passive Optical Splitter in PON Network

In a PON network, the splitter which is located between OLT and ONU functions as a traffic hub, adeptly managing the flow of optical signals. It operates like a sophisticated intersection, directing the singular flow of optical fibers to various users or devices, ensuring the efficient circulation of signals throughout the network, much like optimizing traffic at a hub. The intelligent scheduling and allocation capabilities of the splitter enable the entire network to function in an organized and coordinated manner, meeting users' demands for high-speed optical communication. The passive optical splitter is essential for splitting a single Point-to-Multi-Point (P2MP) physical fiber network. By connecting with OLT and ONU, the fiber splitter can achieve split ratios of 1:2, 1:4, 1:8, 1:16, 1:32, and more. Optical splitters take a single light source (a single fiber optic strand) and refract and duplicate it multiple times to "outbound" fibers. In its simplest form, an optical beam splitter divides a light source in two by using two back-to-back prisms.

Figure1: Passive Optical Splitter in PON Network

Benefits of Passive Optical Splitter

• Splitters offer a cost-effective solution, allowing multiple users to share a single fiber link, reducing the need for individual fiber runs to the hub.

• Splitters are electronics-free, consuming no power, aligning with the passive nature of Passive Optical Networking (PON). They come in various split ratios, such as 1:8, 1:16, and 1:32, meaning a single-mode fiber link can potentially serve 8 subscribers.

• PON networks replace copper cables with smaller, cost-effective single-mode fiber optic cables. Passive Optical LAN (POLAN) utilizes PON in local area networks (LANs).

• The deployment of passive optical splitters simplifies the network architecture by eliminating the need for active components such as powered switches or routers. This results in a more straightforward and cost-effective network infrastructure.

• As passive devices, optical splitters have no electronic components and, therefore, have higher reliability. They are less prone to malfunctions, require minimal maintenance, and contribute to the overall robustness of the optical network.

• Whether deployed in GPON, EPON, or other PON architectures, passive optical splitters exhibit compatibility, making them versatile components that can be integrated into various optical network environments.

• Splitters allow multiple users to share a single optical fiber, optimizing the use of fiber resources. This reduces the need for dedicated fibers for each user, resulting in cost savings and efficient network design.

Limitations of Passive Optical Splitter

• Locating issues with a splitter can be challenging and time-consuming, leading to increased expenses.

• Problems like bad splices and fiber damage are troublesome to find and repair, requiring fusion splicing for damaged fibers or bad splices.

• Dirty or damaged connectors may increase return loss and insertion loss, impacting bit error rates and causing signal loss. Cleaning or replacing connectors resolves this issue.

• Broken or faulty splitters can result in varied splits, affecting subscribers differently. Repairing or replacing the broken splitter resolves this problem.

• Cross connections, where connectors are incorrectly placed, can occur, and finding the exact location of the issue is challenging. Identifying the correct port and restoring service resolves this problem.

• Macro-bends require an OTDR for detection. Testing optical signals at 2 wavelengths helps locate the bend, and gently moving the fiber optic cables removes the bend, resolving the issue.

Conclusion

In conclusion, while PON splitters play a vital role in optimizing signal distribution and offer numerous benefits such as cost-effectiveness and enhanced reliability, it's essential to be aware of potential challenges like locating issues and addressing various connectivity problems. Despite these drawbacks, the overall efficiency, simplicity, and versatility of passive optical splitters make them indispensable components in the ever-evolving landscape of optical networks.