CommScope Definitions: What Is Fiber Network Convergence?

It’s something we’ve heard a lot about – and even based much of our mission on. Fiber network convergence. What is it, and how does it work? Wes Oxlee explains in today’s CommScope Definitions series.

This blog post is part of a series called “CommScope Definitions” in which we will explain common terms in communications network infrastructure.

Fiber network convergence refers to the combination of multiple services within a single access network. In other words, a single pipe is used to deliver all or multiple forms of communication services. For example, fiber-to-the-home (FTTH) networks have an extensive footprint that is perfect for supporting fast-growing mobile applications such as distributed antenna system (DAS), small cell and Wi-Fi backhaul and/or Centralized-RAN front-haul. Through fiber network convergence, a service provider could deliver a wider range of services, adopt new business models, offer innovative services and enter new markets.


The process of fiber network convergence is primarily driven by the development of enabling technologies, user demand and the service providers’ capabilities. Large incumbent service providers have both wireline and wireless operations, so converging onto a single network and maximizing asset utilization makes excellent business sense. Real-life examples have occurred where an FTTH network was built, and several months later, the same construction crew dug up the same street to lay fiber for a cell site, which is wasteful and disruptive. Network convergence would mean one build-out that could be utilized for multiple service delivery platforms.

For smaller telcos, utilities and municipalities – who have more limited budgets – addressing multiple market segments, adding revenue streams and de-risking the business case may be critical elements in network convergence. A city may have a project to fiber up schools and government offices, another project for traffic lights and security cameras, one for Wi-Fi in the city center and one for residential high-speed internet. By converging multiple applications onto a single fiber network, this project now has more stakeholders, more sources of funding and greater economies of scale.

The spare capacity within these FTTH networks can be marketed as ‘virtual dark fiber’ or wavelength services and would be far less costly yet faster to deploy than laying point-to-point dark fiber. Most FTTH networks today are using just two or three wavelengths – one for Gigabit Passive Optical Network (GPON) downstream, one for GPON upstream, and one for video overlay. The vast spectrum of C/DWDM wavelengths remain unused, and hence offers a path for growth and evolution. 

Service providers can use the same fiber strand but keep cell site traffic and residential GPON traffic on different wavelengths. Passive C/DWDM modules are put at both ends of the fiber to combine/separate the different wavelengths. Alternatively, you can keep traffic on separate fiber strands, and design the connectivity at the hubs and closures to appropriately route the traffic.

One challenge is that obtaining dark fiber for wireless applications can often be a lengthy and costly process. With cell densification accelerating and 5G on the horizon, the availability of fiber becomes a potential bottleneck. The demand for fiber-based backhaul and front-haul will only continue to increase in wireless networks, however. This is an aspect of network convergence that needs greater collaboration and foresight. What are your thoughts?