Passive optical networks (PONs) have been through many iterations over the years. We've seen significant upgrades in bandwidth and the number of splits we can perform. In the past, if we wanted to upgrade from one PON architecture to another, it meant replacing expensive optical line terminal (OLT) equipment and customer premises equipment (CPE). With the new Next-Generation Passive Optical Network 2 (NGPON2) and other next-generation PON designs, it is now possible to add new higher bandwidth services over your existing PON feeder fibers without replacing all your expensive network gear that is already in place. By using new passive Wavelength-Division Multiplexing (WDM) devices called CoExistence Elements (CEs), we can now overlay these new technologies using new wavelengths that do not interfere with your legacy PON deployment.

Those same feeder fibers that are serving residential customers can now be used for new technologies like 5G fronthaul and business class gigabit dedicated services. Think about it as creating a double decker bus like the ones seen in England. We are using the same one traffic lane (or fiber), but we are stacking more services on top of the existing ones, allowing us to transport more people (or information) using the same infrastructure. In the past, to provide these types of services, we would need multiple fibers to provide multiple services. One fiber would be used for Gigabit Passive Optical Networks (GPONs) and we would use another fiber for business class Course or Dense WDM services. This is because the wavelengths used in GPON overlap with some of the commonly used wavelengths in WDM applications. With these new generations of PON (like NGPON2), the wavelength maps are designed so that they do not interfere with one another and they can 'coexist' on the same fiber. For those with long memories like me, it is useful to compare this new technology to overlaying Radio Frequency (RF) Video on to a Glass fiber (RFoG). Instead of using a Full Service Access Network (FSAN) WDM to insert the 1550nm video signal on to a PON feeder fiber, we are inserting multiple gigabit channels on to our GPON feeder fiber using a CE.

In these new types of networks, the CEs introduce a small amount of insertion loss due to filter loss and fiber connectors. It will be paramount to ensure that all your fiber connectors meet low loss/high quality requirements like Clearfield's FiberDeep® specification. Instead of just carrying residential internet and voice traffic on these feeder fibers, there may be Quality of Service (QoS) agreements that penalize for downtime. Any issues created from dirty or damaged end-faces become more costly. Do you really want to trust the health of your network to a cheap, low-quality 1x32 splitter? If not, be sure to use a splitter from Clearfield that optimizes your performance potential. Also ensure that any fiber management gear is designed to provide easy access for cleaning and maintenance, bend radius protection, physical fiber protection, route diversity, density and scalability.

So what does this mean? It means that we can increase the revenue potential of our existing FTTx plant using these new technologies. We can now provide higher speed services or fronthaul for 5G sites without having to dedicate fibers or install new ones. With this new technology, we can help turn greenfields AND brownfields greener ($) by allowing us to provide higher revenue services over our GPON networks. If you want to know more, please reach out to Clearfield.

By Tom Warren

Tom Warren has over 10 years of experience as an Application Engineer for Clearfield. Tom provides customer support across the United States, listening to the needs of customers and aiding in the design of fiber termination and optical component systems that will meet their network needs.

Tom also offers the Clearfield customer on-site training of fiber applications. His expertise includes in-depth knowledge of WDMs, FTTH and CATV Fiber Optic solutions, and he trains extensively on fiber management basics and best practices.

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Clearfield Inc. published this content on 12 November 2018 and is solely responsible for the information contained herein. Distributed by Public, unedited and unaltered, on 12 November 2018 15:58:10 UTC