Evolution and Revolution – Paths to 10G Broadband

The development and introduction of several new cable network access technologies, extending from the headend into the home, has moved at a remarkable pace over the past few years. This rapid pace of innovation has been driven by increasing consumer demands placed on current networks—and the resulting rush to offer multi-gigabit per second services to the home—along with the growth of alternative access network technologies like fiber to the home (FTTH). As such, the sheer number of choices for optimizing and evolving cable networks may seem daunting. Therefore, many cable operators may use 2024 as an opportunity to step back, take a deep breath and assess how their current and future network needs align with the abundance of solutions that are available now and will be in the future.

While game-changing, revolutionary network technologies such as Distributed Access Architecture (DAA) and Node PON remain viable options for many cable operators, others are primarily interested in optimizing their current network assets to provide increased speeds and capacities in a cost-effective manner. It is also expected that next-generation Extended Spectrum DOCSIS® (ESD), Full Duplex DOCSIS (FDX) and Unified DOCSIS 4.0 network solutions will continue to gain traction with cable operators in 2024. The goal, as ever, is 10G. The primary question for cable operators in 2024 will be when and how they will get there.

There are two general answers to this question. The more conservative approach is optimizing existing DOCSIS 3.1 network assets to maximize their capacity and throughput speeds. This approach enables cable operators to offer consumers premium, high-tier services while minimizing capital expenditures and disruptions to the network. On the other hand, some cable operators will be interested in evolving their current DOCSIS 3.1 network assets for DOCSIS 4.0 operation. This more aggressive approach will involve qualifying and deploying new DOCSIS 4.0 equipment in the headend and outside plant. In the short term, this evolutionary approach will require more capital resources, but will bear fruit beyond 2024 as the evolved network operates with full DOCSIS 4.0 speeds and capacities.

Despite the many and varied technologies available to cable operators, this article focuses on three solutions for optimizing and evolving cable networks that will likely generate significant interest in the industry in 2024.

Optimizing Current DOCSIS 3.1 Networks

After the large uptick in bandwidth consumption during the COVID-19 pandemic, when many people were working and attending school from home, bandwidth consumption has since reverted to the mean—in this case approximately 18 percent compounded annual growth in downstream and 20 percent compounded annual growth in the upstream. At the same time, with 89 percent of homes and businesses having access to gigabit services,[1] these services are clearly the new norm.

In this competitive environment, cable operators must continue to optimize and evolve their networks to keep pace. In fact, the primary advantage of DOCSIS 4.0 over DOCSIS 3.1 is expanded spectrums/bandwidths and the concurrent increase in network capacity. DOCSIS 3.1 plants operating at 1.2 GHz in the downstream and 204 MHz in the upstream have typically had limited speed tiers available to homes because of the limitations of DOCSIS 3.1 CPE chipsets. These chipsets could only bond up to two OFDM channel blocks and 32 single-carrier QAMS (SC-QAMs) in the downstream.

Thanks to advancements in DOCSIS 3.1 CPE chipsets, however, next-generation DOCSIS 3.1 CPE devices can support bonding of up to four OFDM channel blocks and 32 SC-QAMs. What makes these gains especially exciting is that they support new, higher service tiers to subscribers by simply deploying these CPE devices—no additional network upgrades are required.

In addition to—or in place of—the new DOCSIS 3.1 CPE, cable operators can also deploy DOCSIS 4.0 CPE on a DOCSIS 3.1 CMTS to enable the bonding of five or more OFDM channel blocks for even higher service tiers—again, with just CPE upgrades. This approach helps future-proof the network for full DOCSIS 4.0 operation while realizing partial DOCSIS 4.0 capacity in the downstream.

By surgically targeting homes that subscribe to premium, high-tier services with these enhanced CPE devices, cable operators can optimize the capacities and throughputs in their existing networks and support premium gigabit services; new D3.1 CPE deployments in either mid- or high-split DOCSIS 3.1 networks support speeds of up to 8.8 Gbps in the downstream, while new DOCSIS 4.0 CPE deployments support speeds of up to 9.5 Gbps in the downstream. Both devices support speeds of up to 1.7 Gbps in the upstream. These gains enable cable operators who don’t have any immediate plans to upgrade their networks for DOCSIS 4.0 operation to remain competitive at lower cost.

Node PON

Next-generation Node PON technology is an excellent solution for select business customers, high-bandwidth residential subscribers, MDUs, rural deployments, among other market opportunities. Node PON solutions are compatible with current Brownfield HFC cable networks, supporting both the evolution from traditional coax technologies and a revolutionary approach to extending the edge of the network. They are also a key component in Greenfield broadband expansion initiatives. In both deployment scenarios, Node PON technologies can be seamlessly integrated with cable-friendly OSS/BSS platforms, providing best in class solutions with lower cost of ownership.

Node PON solutions are modular and operate via an R-OLT device installed in a node or VHub. Cable operators will want to choose either IEEE EPON/10G EPON or ITU GPON/XGS-PON to evolve existing Brownfield networks or extend a network via Greenfield builds. IEEE EPON/10G EPON requires minimal changes to current CPE and headend architectures and is fully compliant with CableLabs DPoE v2.0 standards. By integrating with standard DOCSIS interfaces, IEEE EPON/10G EPON lowers the cost of deployment for cable operators. ITU GPON/XGS-PON operates from a cloud-based PON Domain Manager that supports platform interoperability for provisioning and ONU management, as well as zero-touch on-boarding and provisioning speeds deployment.

Virtual CMTS

Virtual CMTS (vCMTS) has several operating benefits—including scalability, reduced power consumption and space savings—that prepare the cable network for next-generation outside plant technologies. Most importantly, it provides the flexibility and operational transparency required to maximize the benefits of DAA and Node PON operation in both new and existing network architectures.

Virtual CMTS operation splits and moves access network functions from specialized CMTS or CCAP hardware to software running on commercial, off-the-shelf (COTS) servers, creating significant energy and cost savings in the headend. vCMTS can quickly and efficiently port functionality from a chassis-based CMTS to a virtualized platform, providing a seamless path from hardware-based CMTS operation to the cloud for traditional CMTS operators while significantly extending the edge of the network when deployed in conjunction with DAA.

Looking Ahead

By the end 2024, cable operators will have a clear, targeted strategy for optimizing, evolving and/or revolutionizing their networks. No matter which direction they take, CommScope is the ideal partner to help cable operators achieve their network goals, from optimizing and extending DOCSIS 3.1 networks to driving fiber to the home.

This article was first published in The Fast Mode.

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[1] https://www.ncta.com/broadband-facts. Accessed on 11-10-23.