How many years have we been talking about the need for cable operators to migrate toward fiber and go “deep” to address the problems of traditional MSO architecture? It’s been the better part of a decade, if you can believe that. The future is—emphatically—now.

You’ve heard me say before that cable providers are in a bandwidth arms race as residential and business subscribers demand more capacity at lower prices. Consumers want streaming content at 4K resolution to feed large-screens and handheld devices, while business subscribers need speed for a cloud-based applications world—providing everything from basic PBX dial tone to specialized vertical services through a monthly subscription.

Plotting a sound and future-ready migration path from legacy DOCSIS technologies to advanced DOCSIS and/or fiber technologies can be fraught with challenges but must happen, as existing MSO infrastructures can’t keep up. Moving away from the traditional DOCSIS-based, head-end-centric network to one that is open, distributed, disaggregated and scalable positions cable operators with solutions that work today and in the virtualized world of the future.

A fiber deep architecture allows MSOs to push fiber as far to the edge as possible to take advantage of improved performance and smaller service groups. Fiber deep effectively moves the “muscle” of the network out of the often congested head-end and closer to the customer, giving smaller numbers of customers significantly more bandwidth from hundreds of megabits to multiple gigabits. Such an increase in capacity means carriers can offer a better subscriber experience, which will become increasingly important as competition to keep customers happy with connected service grows.

Competition from FTTH-equipped phone companies is on the rise. AT&T plans to reach nearly 13 million locations with fiber in the near future. And Verizon is actively promoting NGPON2/FiOS and looking to expand its FiOS footprint through its One Fiber program.

The future 10+ Gigabit network is clearly fiber. But simply deploying fiber or new DOCSIS technologies like DOCSIS 3.1 or FDX increases head-end congestion—even with the latest Cable Modem Termination System (CMTS) and Converged Cable Access Platform (CCAP) equipment deployed.

However, these functions can be distributed and virtualized in a “fiber deep” strategy to avoid those problems. Disaggregation of CMTS and CCAP technologies out of the head-end and moving them closer to the customer with fiber enables higher speeds. This also eliminates a lot of dedicated, proprietary hardware at the central office that takes up space and sucks power, which reduces operational expense. Reducing costs, helping our environment, and maintaining happy customers gives new meaning to achieving a “triple play!”

The most promising, next generation technologies to that end include 10G Ethernet Passive Optical Network (10G-EPON), DOCSIS 3.1, and FDX, which have the capacity to double the useful life of a cable operator’s network investment. They allow a baseline for fiber deep deployments and upgrades to provide a high-speed framework to deploy distributed access architectures (DAA) that scale to deliver the bandwidth needed in a multi-gigabit world expected to support services like 4k video and virtual and augmented reality.

Planning for Virtualization

Software defined access (SD-Access) architectures built on top of disaggregated infrastructures leverage the ongoing evolution of open standards, software defined networking (SDN) and network function virtualization (NFV). Operators can build and operate modular, component-based, multi-vendor network systems that can easily scale to add services with this enhanced, bandwidth-rich environment.

By leveraging open systems, MSOs can build networks based on their specific network topology and service requirements, selecting the customer premises equipment (CPE), middleware and access platforms that best meet their needs. New customers and new services are easily added through a plug-and-play model using open interfaces, while the MSO is not locked into a specific vendor solution with all of its proprietary burdens.

SDN and NFV originated in data center networks with the same technologies now being applied to telecom and MSO networks. Adding services and optimizing performance can be done virtually in real time with SDN/NFV rather than having to use proprietary, vendor-centric hardware for each function.

Automation is becoming a more important feature of SD-Access networks. Established tools and supplemental scripting, when needed, reduces service provisioning times, human error and IT complexity—enabling customers’ self-service capabilities. These SD-Access networks can also provide subscriber analytics and insights into the network to further enhance customer experience by anticipating needs and problems, and even fixing issues before anyone is aware.

SD-Access enables network flexibility and agility to scale in a multi-Gigabit world, supporting thousands of Remote Physical Layer (R-PHY), Remote Optical line terminal (R-OLT) or Remote Media Access Control/Physical Layer (R-MAC/PHY) devices in the network. SDN-based systems provide the management and service orchestration necessary to rapidly deploy and support R-PHY, R-OLT and R-MAC/PHY devices.

Using a standalone fiber or coax aggregation architecture combined with a non-blocking leaf-spine fabric and aggregation switching, service providers get a multi-Gigabit scalable network access architecture from day one. Leaf-spine switching networks of this type have full meshed connectivity to spine switches.

Within this architecture, programmable network elements can scale horizontally. As the number of Ethernet aggregation ports in an SD-Access network grows over time, leaf and spine switches can be added as needed, with meshed connectivity staying in place. Leaf and spine switching functions are sized to accommodate growth and can be easily upgraded when needed—while operators migrate toward networks of the future.

Hossam Salib is VP, Cable & Wireless Strategy at Adtran.  He drives the company’s strategy supporting the cable industry globally with new technologies and products for building the next generation cable access networks.  He is also responsible for driving Adtran’s wireless strategy, building a Fixed Wireless product portfolio to support carriers’ worldwide building next generation Fixed Wireless broadband access and backhaul networks.