FTTP or Next-Gen HFC? It's Complicated

As cable operators mull network upgrades and enhancements, many are wrestling with whether to spruce up their existing hybrid fiber/coax (HFC) networks or just plow ahead with fiber-to-the-premises (FTTP).

In recent years, upgrading HFC (to DOCSIS 3.0 or 3.1) was the typical winner, given the relatively small incremental costs involved and the performance boost that came with those upgrades. Meanwhile, FTTP (PON-based systems as well as RF-over-Glass options that let cable ops utilize legacy set-tops and modems) has been winning out in smaller, more select situations, primarily in greenfield deployments.

That debate continues on today but it's a bit more complicated than it used to be. While FTTP technologies and the deployment costs involved are well known, the situation (and the discussion) is evolving with the emergence of new next-gen HFC options.

The HFC side of the equation is not as simple as before because cable ops now need to weigh the financial and operational costs of new and more complicated distributed access architectures as well as emerging technologies such as Full Duplex DOCSIS and Extended Spectrum DOCSIS, which are both slated to become part of CableLabs's evolving DOCSIS 4.0 specifications. Also factoring into the discussion are the complications and potential benefits of virtualizing the HFC network.

Jack Burton, principal at Broadband Success Partners and a vet of the cable and telecom industries, analyzed the situation Wednesday during a Broadband World News webinar sponsored by Adtran titled "FTTH & Next-Gen HFC: Key Considerations in Building Cable's 10G Platform." Burton weighed the myths and realities and the pros and cons for a wide range of variables that go into these decisions, including the potential for service disruptions, construction costs, the need to swap in new terminal equipment, backoffice provisioning and the effects on technician tools and training.

When all of those considerations are rolled up, there's still no clear-cut or hard-and-fast winner regarding which direction an operator should take in all cases. However, going with a full FTTP upgrade appears to be in better position today than in prior years due in part to the complexities and costs associated with some of the new next-gen HFC options now on the table.

Next-gen HFC, for the purpose of this analysis, is defined as node+0 (the elimination of the amps between the node and the home, sometimes referred to as "fiber deep), or a distributed access architecture (DAA), or node+0 paired with DAA.

With respect to service disruption, there's going to be some with both next-gen HFC and FTTP. However, Burton says FTTP upgrades are poised to be less disruptive, given that a FTTP network could be built in parallel to the legacy HFC network, allowing the service provider to swing subs over to the new network.

The cost of maintaining HFC is higher than FTTP. Burton cited data from an unnamed tier 1 cable operator that was spending about $1,100 per mile per year on HFC network maintenance, compared to a mere $100 per mile per year on FTTP.

Burton sees no distinct advantage with construction of next-gen HFC and FTTP. Next-gen HFC, he says, has "hidden costs" in areas such as the need for high-output nodes for DAA deployments, and the possible need to boost network powering and switch out tap plates or tap housings.

The costs to deploy fiber remain significant. "There's no getting around that," Burton said. However, next-gen HFC options whereby the bandwidth is being expanded (in either the upstream or downstream, and maybe both) also have high costs associated with them, thanks to the changes made to the plant, the need for more fiber at the node and the disruptive and costly requirements involved in swapping out terminal equipment.

Meanwhile, the nod goes to next-gen HFC in the category of backoffice provisioning. Cable ops won't need to make sweeping changes in that area for upgraded HFC networks, and CableLabs has also developed ways to emulate DOCSIS provisioning on EPON networks. "Doing nothing is certainly easier than doing something," Burton said.

For technician training and tools, next-gen HFC has the advantage since that fits in with a cable operator's heritage and knowhow. However, in greenfield scenarios, Burton views that as a tie, noting that the degree of difficulty in handling fiber drops and coax are about the same.

Most MSOs still eyeing next-gen HFC
Even though FTTP upgrades might hold more allure to MSOs as they mull their network upgrade plans than in years past, Burton said the bulk of cable operators are still considering next-gen HFC.

However, FTTP is "very popular" in the tier 2 cable operator market, he said. "There are a lot of systems doing it."

It's the opposite case with tier 1 cable operators, which have largely relegated FTTP to greenfields and some success-based, targeted deployments. However, Altice USA is an outlier among US tier 1s as it moves ahead with an aggressive FTTP upgrade plan.

This one-size-does-not-necessarily-fit-all scenario is reflected well by BCI, which operates both metro and rural systems via its ownership of Buckeye Broadband, Telesystem and MaxxSouth Broadband.

Tommy Taylor, BCI's VP of IP, video and design services, explained that his company has taken multiple approaches with network-related decisions, driven by what consumers need in those markets, the costs involved and what future technology advancements each one presents.

Taylor said BCI's traditional HFC network is 870MHz (with a 5-42MHz split for the upstream). But the cableco has also been going with "brownfield" upgrades up to 1.2 GHz and a 5-85 split for the upstream. DOCSIS 3.1 is widely deployed using traditional cable modem termination system gear from Cisco Systems and Arris/CommScope, but the company has also been working with Harmonic and its virtual "CableOS" platform. BCI also has FTTP in its toolbox, as it has used both RFoG and GPON, he added.

Related posts:

• Why FTTH May Trump Fiber Deep for Cable
• The Road to DOCSIS 4.0
• CableLabs Kicks Off Pursuit of DOCSIS 4.0
• CableLabs CEO: 10G a 'Collection of Technologies'

— Jeff Baumgartner, Senior Editor, Light Reading