The cable industry's standards-making body has blessed the enclosure specs for the Generic Access Platform (GAP), as well as the specs for interoperable service modules that will snap into the next-gen nodes.

Jeff Baumgartner, Senior Editor

September 21, 2021

7 Min Read
SCTE clears way for standardized network nodes

Taking a step toward network and service convergence, the Society of Cable Telecommunications Engineers (SCTE) recently approved two standards for the Generic Access Platform (GAP), an initiative focused on the development of standardized nodes for access networks.

With a primary focus on the North American cable market, the first two SCTE standards cover GAP node housings/enclosures and the specifications for the various interoperable power, compute and service modules that will snap into GAP housings like Lego bricks.

Figure 1: 4531.jpgA schematic of the SCTE-specified dimensions for a GAP node.
(Source: SCTE)
Click here for a larger version of this image.

GAP, an initiative spawned more than three years ago and largely driven by Charter Communications, sets a path for nodes and modules that will support DOCSIS, PON and wireless services – including Wi-Fi and CBRS and wireless backhaul – and, potentially edge compute.

SCTE, which merged with CableLabs in January, made note of the GAP-related milestone via Twitter on September 19.

Approval of the standards, which were approved in early September, should pave the way for node makers and other vendors poised to join the GAP ecosystem to push ahead with their product development plans. The GAP market is also expected to open the door to vendors and other companies that might want to take on the role of master integrator.

GAP benefits

One main thrust of GAP is to steer the industry away from an array of proprietary nodes that handle discrete services or functions and to instead stitch everything together into a standardized, evolvable package.

The specs themselves outline several specific benefits, including a reduction in the number of custom designed and manufactured housings as cable operators start to move ahead with a distributed access architecture (DAA) that will place key electronics and functions toward the edge, resulting in deployment and use of a much greater number of nodes than what's there today. GAP also aims to expand the life of deployed node housings by re-purposing them with various service modules rather than having to replace them outright. The standards also aim to facilitate interoperability between different suppliers and vendors.

Vecima among suppliers bullish on GAP

The emergence of GAP could threaten the position of incumbent node suppliers, such as Cisco, Harmonic and CommScope, but open the door for vendors that are trying to break in or grab a bigger slice of the market.

Vecima Networks is among suppliers that's targeting the GAP opportunity. In February, Vecima Networks struck a deal to acquire the intellectual property that ATX Networks had developed for a GAP node enclosure. That deal effectively handed Vecima ATX's drawings and schematics and as well as early prototypes for a GAP enclosure. Vecima also agreed to license the intellectual property back to ATX, should ATX opt to pursue GAP products at some point down the road.

"We absolutely plan to make [GAP] a real product and build real modules," Clay McCreery, Vecima's COO, said.

Vecima, he said, expects to have standardized GAP housings ready by 2022 in preparation for production field deployments of GAP products expected to take hold by 2023.

Colin Howett, Vecima's chief technology officer, said Vecima had planned to show off a GAP prototype at SCTE Cable-Tec Expo, which was originally set to run next month in Atlanta. With that event shifting to an all-digital format, Vecima now plans to show off its latest GAP-facing handiwork at its virtual booth.

"We're pushing really hard to get this out there and we think this is the node of the future," Howett said of GAP. "It's going to last for years, decades … and really establish a space to put all of the node equipment in the future."

Early on, Vecima will also focus on GAP modules that support distributed access architectures for both DOCSIS and PON networks. Vecima believes that the modules it develops will interoperate with new GAP housings as well as its own pre-GAP multi-access network node, the Entra Access Node EN8100, with "minor metalwork changes," McCreery said. Vecima's EN8100 and the new standardized GAP nodes will use a similar architecture, he said.

It's important for those modules to work across those node platforms, McCreery explained, because some operators will travel the GAP path and others won't.

"Not everybody believes in it," McCreery said of GAP. "But we think there will be a great number of MSOs that will really enjoy the opportunity to have that as their platform for the next several decades. They'll just be adding modules to it."

A glance at the standards

The Generic Access Platform Enclosure Specification, dubbed SCTE 273-1 2021, defines a mechanical housing (including the housing's dimensions and materials) that provides physical support for electrical and mechanical components and environmental protections for the internal components. The specs divide the GAP enclosure into two sub-assemblies: a Base and Lid.

At a high level, the GAP Base will contain the power supplies, RF amplifiers and connectivity to the box. The Lid will contain the digital elements and service modules, such as remote PHY and remote MACPHY devices, PON modules and, possibly, edge compute modules.

Figure 2: 4518.jpgClick here for a larger version of this image.
(Source: SCTE)

The GAP Base is specified to provide mounting, power and communication for up to four application-specific modules, able to fit four single-sized Base Module slots or two double-sized Base Module slots, or a combination of two single-sized and one double-sized slots. Up to six application-specific modules can be mounted in the GAP Lid, though individual modules can use more than one module slot as needed for thermal dissipation and/or component space, according to the standard.

Figure 3: 4544.jpgClick here for a larger version of this image.
(Source: SCTE)

The other related standard – SCTE 273-2 2021 – defines the specs for GAP modules. Per the standardized design, modules can be swapped in and out. The GAP Lid itself is also removable and replaceable, obviating the need for the operator to cut a new node into the plant once the original GAP node is installed. That aims to eliminate the need for additional permits and construction costs when an operator expands or upgrades the capability of a GAP node.

Though the initial GAP standards are largely focused on the needs of the North American cable market, the standards do make note that "areas of further investigation" include larger or smaller enclosures and fulfilling the specific needs of markets outside of North America.

"We all want to get a standard GAP formfactor than can be used in multiple places," Howett said.

SCTE has been asked if there is any formal work underway to create new GAP standards or to adapt the current GAP standards for markets such as Europe.

Update: "SCTE's new GAP standard applies to strand-mount housings in Europe and other locations across the globe," Dean Stoneback, SCTE's senior director of engineering and standards, said in a statement to Light Reading. "While there is no current initiative to develop a GAP enclosure standard for European-style pedestal housings, SCTE would be eager to coordinate such a project with European operators in the future. In the meantime, GAP-compliant modules can be used in European-style pedestal housings even without a standard in place."

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— Jeff Baumgartner, Senior Editor, Light Reading

About the Author(s)

Jeff Baumgartner

Senior Editor, Light Reading

Jeff Baumgartner is a Senior Editor for Light Reading and is responsible for the day-to-day news coverage and analysis of the cable and video sectors. Follow him on X and LinkedIn.

Baumgartner also served as Site Editor for Light Reading Cable from 2007-2013. In between his two stints at Light Reading, he led tech coverage for Multichannel News and was a regular contributor to Broadcasting + Cable. Baumgartner was named to the 2018 class of the Cable TV Pioneers.

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