Q&A—CableLabs’ McKinney on Full Duplex, coherent optics and the 'random choice' of coaxial cable

DENVER—Every year at Cable-Tec Expo, FierceCable can count on Phil McKinney for one 12-ounce can of Pepsi’s worth of time. 

That’s about as much as the approachable CableLabs CEO can spare these days, having once again polished specs for a new network technology standard, Full Duplex DOCSIS, in record span, and now plunging full steam ahead on work with coherent optics, various Wi-Fi technologies and 5G trials, among other efforts. 

With multiple constituencies to address at Cable-Tec Expo, the former Hewlett-Packard executive sat down with us and let the iPhone voice memo feature roll for nearly half an hour—about enough time for him to power through his preferred carbonated refreshment and get ready to meet with the next Tier 1 CTO.

Here’s the transcript from our talk, edited for clarity and brevity:

FiercecCable: With big cable companies like Comcast and Altice forming their own research labs, where does CableLabs fit in?

Phil McKinney: It’s real simple. The work that the members do, whether it's Tony Werner [CTO] at Comcast or [fellow CTOs] Jim Blackley at Charter or Kevin Hart at Cox, their goal is the one- to three-[year window]. Their job is to actually deploy the network. CableLabs, over the last two years, we’ve shifted our focus to be in that three- to eight-year window. What we’re building is the next thing Tony’s lab picks up to get into the network—Full Duplex DOCSIS or coherent optics. Those are things in which there isn’t even a vendor for them to go talk to yet, because it doesn’t exist. When [a technology] gets to that three-year mark, in some cases, the members will self-identify and say, ‘We want to be the light house for that innovation.’ And they’ll bring it into their labs and work with their vendors to actually translate the science we do into a product they can buy.  

FC: But Comcast talks about how it's developing technologies like AI years out. You don’t ever find yourself in conflict?

PM: No, because Tony and [Comcast Cable CEO] Dave Watson see our pipelines. Our work, if you think about it, is really in infrastructure, whether it’s DOCSIS, fiber optics… We’ve tripled our fiber-optics team in the last two years. People don’t think of us for fiber, but we’re running coherent optics with 2 terabits over a single string of fiber. Nobody is running 2 terabits over a single string of fiber. 

FC: That seems like a lot to me.

PM: It is a lot, given today, [the network standard is] 40-gig, and we’re running at 2,000 gigs on a single strand of fiber. So we’re into Wi-Fi, 3.6-gig, wireless … we’re in 5G trials with members. So we don’t play in the application experience level. Things like RDK aren’t a big play for us. The vendors are already doing great work in that. We’re into that hardcore science.

FC: Let’s talk about Full Duplex, for which you recently published specs. What did that take you, only a year?

PM: If you had inside knowledge of the project, we were probably at around 14 months. We finished the specification. We actually worked very well with the silicon vendors, so they had very early lines of sight. They could roll it into their road maps. It’s not like a big jump--they can just roll it in as part of their next step on DOCSIS 3.1. There’s a lot of interest in it. We’ve got a lot of members queued up. If the vendors hear from the members, and they’re interested, it reinforces that if they build it, the members will buy it. It’s not like they’re going to build it and hope they buy it. And that’s part of the role we play at CableLabs—we de-risk R&D spending for the vendors. 

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FC: How long will 10 Gbps speeds cover the industry?

PM: Download speeds grow around 40% a year. You can run the numbers. The chart is pretty darned predictable. It’s cable’s version of Moore's Law. We’ve got 1-gig services out there; the next step is going to be 2-gig. There might be some 3-gigs early in the game. But when we get to 10-gig, you’re out there 2024, 2025-ish. The next question is, what are we going to do with it? What’s the service that requires it? The question I get asked a lot is, so what application out there uses 1 gig? The most prominent application today is Speed Test. There’s nothing else that can drive 1-gig usage. If you look at consumers who buy the 1-gig service, and look at their usage pattern. Maybe they had 300 Mbps and they moved up to 1-gig—you look at their usage patterns, and they haven’t changed. You can’t use that much more Netflix, or that much gaming … VR hasn’t kicked in yet. You’re investing billions of dollars in the network, but you don’t always have clear line of sight as to what people are going to do to consume that offering.

FC: I just heard Dave Watson say that Comcast has to show people what they can do with 1-gig. 

PM: You do. And that’s why we did the “Near Future” video last year. That was really our attempt to try to inspire innovators. We’re building these networks, but we’re not building VR hubs; we’re not building gaming environments; we’re not going to build small-business immersive collaboration. We think these are some interesting things, and we really want to inspire people. We're building the platform for you to work on top of. Work with us. If you’ve got some unique characteristics you need in the network, work with us, because if we get that far in advance, we can innovate on that. And then when it gets built in, whatever that innovation is, it’s ready to go. 

FC: So is the HFC network done after Full Duplex? Can you wring any more performance out of it?

PM: Oh yeah. I was recently meeting with some of the original guys who started the cable industry. They get together every quarter in New York. And I was there giving them kind of a technology update, and we were all laughing at the random choice of coaxial cable being selected as the transport medium. I don’t know who made that call, but that was a phenomenal call because the carrying capacity of that coax and the fact that it also carries power is second to none. Whether it's an HFC architecture or some other means of transport on that coax, it doesn’t matter. That coax has a very long life ahead of it. 

FC: So tell me more about coherent optics. 

PM: The bottleneck now is in the fiber deep side. Most operators, when you inventory them, in most nodes, they probably have two strands available. If I only have two strands, and I can only do 40-gig, that’s going to be a problem. Thus, the work we started three years ago on coherent optics. That’s now delivering 2 Tbps.

FC: How does coherent optics work?

PM: It's just started with working groups, so the spec's not done yet. Fiber thinks about transporting information as lightwaves. It uses different parts of the spectrum. Coherent is really about using polarization. I can polarize that light, and therefor radically simplify the transport of bits over that cable. The concept is being used in very long-haul kinds of networks.  We took it and innovated it around point-to-point, short-haul kind of distance. When you do that, you uncover some unique characteristics. At 80 kilometers, if you do the right approach on coherent, you can radically simplify the electronics on the other end. You can do all kinds of nice things to where you can deliver really high speeds at low cost. 

FC: So what about cable guys, like Altice, who are choosing fiber over HFC?

PM: Based on my conversations with Altice, I’m not sure it will be 100% fiber. They have a lot of aerial plants on the pole. If you’re on the pole, and you’re pushing fiber deep, you have to decide if you’re pushing to the pole to where the node is at, or if you should just make a left-hand turn and put it into somebody’s house. They don’t have to dig. For them to do it in the rural markets they also own, that would be really expensive. But in the Northeast, it’s aerial and very tightly packed; it’s almost an optimal environment to take fiber deep. For us, we’re not DOCSIS-focused. For us, it’s really about giving all of our members optionality. 

FC: Do you think 5G will ultimately replace the fixed network?

PM: This is the question we get asked all the time. There’s a very small percentage of U.S. homes to which 5G could deliver services. One reason for that is leaves on trees. High millimeter waves will not propagate through foliage. It won’t penetrate walls and buildings. And in some cases, it won’t penetrate glass. If you’ve got RF-shielded glass, it won’t allow signals in. Also, for 5G, you’ll want a certain amount of housing density. So cities like Boulder, Colorado, are not dense enough. Manhattan is too dense, because I can’t bounce signals in the canyons. So there’s a certain optimal kind of size to deliver that.

FC: What’s your role with the wireless launches going on in cable?

PM: Keep in mind, CableLabs is funded by 60 cable operators, and nearly half of those are mobile network operators. It just happens to be the U.S. is not a big market for us. But we have Rogers, Shaw, Cogeco and Videotron, Liberty, Virgin Media, Altice—50% of our members are both cable operators and MNOs. Starting four years ago, we ramped up our wireless research work. It’s now our largest research team. It’s larger than DOCSIS when you think of total number of researchers on the program. And that includes work we do on Wi-Fi, next-generation unlicensed spectrum work, and our work the licensed spectrum space. We’re supporting five 5G trials around the world with members.