HFC Network

FMA 101: Taking Things Apart to Make Them Even Better

Mar 23, 2021

This month, we continue our CableLabs 101 series by peeling back the next layer of the hybrid fiber-coax (HFC) distributed access network with a recently released specification called Flexible MAC Architecture (FMA). This technology isn’t as well known as DOCSIS®, Remote PHY or Coherent Optics, but it’s just as essential to make 10G a reality in the near future. Let’s take a closer look.

What Is FMA?

Without getting too technical, a big part of what we do involves analyzing how things work. We like to take things apart and see how we can reorganize or alter the components to build better, more efficient products. Essentially, that’s what innovation is all about! In this case, the “product” in question is the DOCSIS technology and the cable access network that delivers Internet to your home.

Some time ago, we figured out how to split key DOCSIS functions into two major pieces: the Media Access Control (MAC) function responsible for DOCSIS processing and the physical radio frequency function (PHY) responsible for DOCSIS signal generation. This initial split became known as Remote PHY, and you can read more about it in our previous blog post here. Subsequently, we built a complementary project involving the redistribution of these functions across the network to enable efficiencies in speed, reliability, latency and security. This newer project is FMA, which defines various ways of restructuring the MAC function’s management, control and data planes to support multi-gigabit data services of the future.

In September 2020, this extraordinary effort—involving thousands of work hours across the global cable industry—culminated in the specification. It’s a library of specifications that gives our industry vendors the technical means to develop interoperable products for our cable community, and it officially welcomes FMA into the 10G technologies toolkit.

How Does FMA Work and Why Do You Need It?

The Converged Cable Access Platform (CCAP)—a nearly decade-old technology—serves as a single platform for both video and broadband services. In a traditional CCAP architecture, all the major network functions, including the MAC layer functions we mentioned earlier, are unified at the headend. However, as consumers’ bandwidth consumption has continued to skyrocket with no sign of slowing down, the cable industry asked: Is there a better way to structure CCAP to prepare our networks for the needs of tomorrow?

The answer was yes.

That’s how the concepts of Remote PHY, Remote MAC-PHY and, eventually, FMA were born. By taking apart key CCAP functions and moving them to other places throughout the network (e.g., a fiber node), we can greatly reduce space and power demands at the headend, creating efficiencies that translate into faster network speeds, lower latencies and overall a better, and reliable cable access network.

Plus, FMA offers cable operators the ultimate flexibility to implement and deploy CCAP functionality in a way that makes the most sense for them. It fully supports the DOCSIS 4.0 requirements and, along with the other tools in the 10G arsenal, can help operators build adaptive and secure networks that can easily handle future demand.

How Does This Technology Affect You and Your Future?

Complete disaggregation of CCAP sounds great, but you might be asking yourself: “What’s in it for me?” As with any 10G technology that we’ll cover in this series, it’s always about improving the end user experience. All those technical efficiencies we talked about basically boil down to more room for data to go through the network at much faster speeds. This means more multi-gigabit services, low-latency applications such as ultra-realistic video experiences and overall a better quality of experience. One day soon, as we continue to build upon cutting-edge cable technologies like FMA, this will become reality.

The September 2020 FMA release is just a part of a much bigger initiative to completely virtualize cable access networks in the near future, so definitely stay tuned! In the meantime, we’ll continue taking things apart and putting them back together in new and better ways to take your connected experiences to the next level.