As a potential future-proofing technology, cable's developing Generic Access Platform (GAP) initiative for modular and standardized nodes is solely focused on what's next for the industry's hybrid fiber/coax (HFC) network. It's also entering the picture to support PON and wireless access network systems that are rapidly becoming part of the industry's ever-evolving multi-access converged network.

Standardized GAP nodes, which will also pack more edge compute and support interfaces for a range of snap-in service modules, will put operators in position to essentially deploy Ethernet down into the neighborhood and connect and unify all of those access technologies under one roof.

That resulting IP backbone into the neighborhood will provide cable operators with "one common converged transport," John Chapman, fellow and CTO of the cable access unit at Cisco, said Thursday during a "LiveLearning" webinar hosted by Light Reading in conjunction with SCTE/ISBE, the organization spearheading the GAP standards initiative. "That's a very, very powerful deployment scenario."

More GAP drivers
In addition to multi-access/network convergence, other inflection points for GAP include the industry's migration to a distributed access architecture (DAA) – whereby physical and processing functions are pushed out toward the edges of the network – alongside the need to deploy more computing power at the edge for new low-latency applications and services.

GAP and DAA will be intertwined as cable operators start to "refresh" their outside plant, push fiber deeper and begin to deploy more capable and future-proof nodes, explained Ed Dylag, market development manager for Intel's Network Platforms Group.

GAP's modular capabilities, he said, will allow cable operators to deploy the new nodes once and then swap in new service modules (for DOCSIS, Wi-Fi, LTE, etc.) as needed without having to replace the core housing.

A GAP node prototype shown at last year's Cable-Tec Expo in New Orleans was focused on DAA with an integrated DOCSIS remote MAC device. Dylag said the next logical "bolt-in" is PON as cable operators continue to deploy more FTTP networks for new builds and enterprise locations.

A third anticipated use-case is the integration of wireless RAN technologies as cable operators become increasingly interested in extending the edges of their networks wirelessly and offloading traffic onto their own networks to help lower their MVNO costs.

Colin Howlett, CTO of Vecima, agreed that modularity is a key feature of GAP, as operators will want to pivot away from today's broad mix of vendor-specific, purpose-built nodes and take advantage of a standardized, modular platform that enables them to replace and upgrade capabilities on already-deployed nodes.

He said it will also be critical to keep the interfaces simple and to avoid over-specifying GAP to ensure that suppliers – including companies that develop the GAP service modules – still have room to differentiate and innovate on top of the standard.

Timing on standards, products still TBD
Work on the initial GAP standards is progressing, but SCTE/ISBE is not pointing to a specific deadline or expectation on when they will be wrapped up. However, writing of the GAP standards is well underway and the general work on the project "has been accelerating this year," Dean Stoneback, senior director of engineering and standards at SCTE/ISBE, said. The standards approval process usually takes about six weeks once the documents are finalized, he said.

Noting that much of the early debate on GAP has been settled, Dylag hazarded a guess that the initial standard could surface sometime this year, putting vendors in position to start building products in 2021.

It's too early to know what the delta between a GAP node and a legacy node will be, but there's no expectation that a more capable GAP node will somehow be cheaper than its predecessors. It's not an apples-to-apples comparison.

"This is going after a new market," Chapman said, noting that today's nodes have been undergoing cost-optimizations for about 20 years.

The GAP era is in its early stages, but Dylag suggested that products based on the standard could be built to play a role outside the traditional cable industry.

While the initial products will be for strand-mounted nodes that are common for North American cable networks, he said future versions could be developed for ruggedized "dog house" enclosures that could be of use by telcos. Such future platforms could be used for "near-premises" deployments supporting enterprises and large business locations, with private LTE networks among the potential use cases, Dylag said.

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— Jeff Baumgartner, Senior Editor, Light Reading