Consumer demand for bandwidth is like an immediate and gaping maw that broadband providers are trying to satisfy. The need is so intense that operators are re-architecting their networks to support greater capacity and faster speeds -- searching to find solutions that don't break the bank, or entire facilities of existing equipment.

In the cable sector, one of the big challenges is figuring out how to feed more bandwidth to optical nodes that connect to consumer homes. Once an operator runs out of space on a chassis that delivers bandwidth to a series of nodes, the obvious solution is to add another chassis in a headend or hub site to increase capacity. Unfortunately, providers are running out of room at those sites, and that's one of the big reasons behind the distributed access architecture (DAA) trend that's now sweeping the industry. (See Cable's DAA Moment Is Here.)

Cable industry vendors have suggested multiple strategies for distributing the access network as a way of adding capacity while also minimizing real estate and power requirements. They include moving different parts of the CMTS or CCAP chassis down to a network node, and various solutions for virtualizing chassis functions so that more network features can be managed through software. The SCTE Cable-Tec Expo show in September was a big coming-out party for these DAA and virtualization offerings, but now the situation has shifted again as early deployments are starting to take place. (See Cable's Upgrade Moment – Part IV.)

Case in point: Cisco Systems Inc. (Nasdaq: CSCO) revealed in March that it had begun shipping a new Remote PHY device (RPD) in volume. Now today at the ANGACOM show in Cologne, Germany, the company is officially launching its "Infinite Broadband" Remote PHY solution, which includes both the new RPD and deployment automation software.

Arris Group Inc. (Nasdaq: ARRS) too is in the deployment phase with its own announcement today of a Remote PHY win with Danish service provider Stofa.

In the immediate term, Remote PHY gives operators the ability to add massive density to a CCAP chassis, which means more bandwidth that can be pushed down to optical nodes. By moving the PHY out of the CCAP in the headend, there's more space for additional ports, and therefore more chassis capacity.

But there's a catch. If operators are pursuing Remote PHY in conjunction with deep fiber deployments -- which is expected to be the case -- the added capacity won't be quite enough to make up for the additional ports that need to be supported. Deep fiber deployments are expected to increase the number of optical nodes in the access network by a factor of ten, if not more.

According to Cisco Fellow and CTO of Cable Access John Chapman, the combination of a Remote PHY solution and updates to Cisco's CCAP chassis will only increase support capacity by about a factor of eight.

In other words, while Remote PHY will dramatically lessen the number of CCAP devices that service providers have to buy when deploying deep fiber, operators will still have to buy more chassis in the near term than they're putting in place today.

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Remote PHY is an intermediate step for operators as they work to transform and ultimately virtualize their access networks. It's certainly good for vendors like Arris and Cisco, which can keep selling "big iron" hardware even as they (and others) work on developing new, truly virtualized solutions. (See Cisco's Open Source Moves Not All Altruistic.)

But it's also good for operators, who not only have a way to meet new bandwidth demands now, but also an opportunity to lay the foundation for the software-defined access networks of the future.

Cisco's Remote PHY configuration solution, for example, uses software in the cloud to virtually introduce a new Remote PHY node to the appropriate CCAP device. It then automatically configures the node to begin carrying traffic. The automation software is also built on NetConf and YANG models, which means it will interoperate with other industry-standard network configuration technologies.

The revolution in cable access networks is happening slowly, but it is happening. Operators are not only adding more capacity to their networks, but they're also putting in the building blocks for greater virtualization and automation. That's a huge opportunity for vendors, and it's why the DAA arms race has begun.

— Mari Silbey, Senior Editor, Cable/Video, Light Reading