Since we are pretty much done with 5G standards, it’s a good time to take a realistic look at the way 5G might actually deploy and how it might impact metro infrastructure and the carrier cloud. I want to stress that operators are internally divided on 5G and its impacts, so I’ve necessarily had to use my own judgment as a filter where competing views have to be harmonized.
Most operators agree that 5G non-stand-alone (the 4G/5G New Radio hybrid) and 5G/FTTN millimeter wave applications in “wireline” broadband will deploy. We can expect to see both get out of the trial stage in 2019. Operators cite a mixture of reasons for the deployment, but the consensus is that it’s really driven by changes in the mobile and video markets, and that the 5G connection is more a matter of using the latest standard for next-gen deployment than that 5G is driving these changes.
At the root of all these drivers is video streaming. Mobile usage is growing every year, and in particular mobile content viewing, including live TV. Cord-cutting is also exploding, reducing the appetite for linear TV. AT&T recently introduced its WatchTV service, which streams 31 channels (36, eventually) for fifteen bucks a month, free to unlimited AT&T mobile customers. Obviously, this means that more mobile capacity will be needed, and it makes sense to build out 5G rather than to try to make 4G work.
The 5G/FTTN hybrid is related to this. Pure FTTH is practical in areas where demand density (roughly, GDP per square mile) is high, but with the decline in the value of linear TV it’s harder to build a business case for FTTH even where demand density is good. DSL doesn’t work well for high-speed broadband, despite advances in the standard, so operators like Verizon are very interested in using 5G mm wave as a tail circuit to fiber to the node. Most people agree that the combination is great for broadband but could deliver TV only in streaming form.
Video demand and 5G, in either NSA or mm-wave form, combine to drive a considerably larger requirement for fiber in the access/metro network. In truth, fiber will be the big infrastructure winner in what’s usually seen as a 5G-driven infrastructure revolution. No matter what kind of RAN you use, you need more capacity per unit area to deliver more video traffic, so we can expect to see a lot of new fiber runs to new nodes or base stations, and more capacity per fiber connection as well. That will accommodate (at least accommodate better) the larger number of users viewing streaming video content and the larger number of hours spent per user doing that.
5G NSA, the mobile form of 5G likely to deploy first, depends on standardization because it depends on compatibility between handsets and RAN. Operators are always reluctant to say that standards aren’t needed or useful in any space, but many think that standardization of 5G/FTTN isn’t nearly as important because it won’t demand a lot of interoperable elements. The operator will control both ends of the radio connection, and the relationship will be fairly static. However, there is at least some thought about having “node convergence” between 5G NSA and mm-wave technology, since it makes sense to leverage fiber runs wherever you decide to do them.
Estimates of how far and fast this first phase will go vary significantly, depending on factors like demand density, competition, and residual capacity in the 4G infrastructure of the area. However, most operators don’t think that there will be widespread 5G NR even in 2020, and that 5G will outstrip 4G in deployment only by about 2022. The 5G/FTTN stuff is likely to roll out faster, and fastest of all where cable TV (CATV cable delivery) is a competitor.
The timing of this first phase has a lot to do with the deployment of 5G beyond NSA, meaning 5G Core. This part of the 5G story is where there’s the greatest difference in viewpoint among and within operators. At the core, perhaps, lies the fact that many senior operator types still think in public-utility terms. You design a service, deploy it, and people use it. This view is rarely held by the CFO organization, however, and that is a big part of the division on the topic.
If you do not see future services as much more than expanded video-centric mobile, then the only driver to 5G Core is whatever impetus MVNO relationships might provide to network slicing. Things like roaming between WiFi and cellular and even satellite could be provided without 5G core, and many operators are unsure whether that capability really benefits the incumbents. Some also wonder whether a lot of MVNO interest wouldn’t just cut into their retail revenue to feed a smaller wholesale stream.
If you think future services are more than video, you probably think they relate to IoT. Unfortunately, I don’t think there’s any topic in networking where fewer people have a realistic vision of progress. Not only that, operators are probably lagging even the (pathetic) level of overall industry realism. Saddest of all, even IoT doesn’t drive a convincing demand for 5G Core. The problem is that everyone knows that “real-time” means “low latency”, but they don’t know the answer to the “how low can you go?” question, rephrased as “how low do you have to go?” Most IoT applications could easily tolerate latency measured in the low hundreds of milliseconds, and that could be provided without 5G core (or even 5G NSA).
The credibility of IoT as a 5G driver, or indeed as a driver of anything, is still a question. An article in Light Reading describes an initiative to come up with 5G justifications, and three were identified; augmented reality, M2M, and medical. Gosh, I remember when “medical imaging” was the justification for practically any new network technology, so I guess that one’s no surprise. To me, these three are tenuous enough to make IoT look good.
I think IoT will emerge, not as a sensor-connect 5G technology but as a cloud-service technology. Because not even that point is accepted, I’m not expecting much from it in the near term. My model says that we can’t expect to see IoT emerge as a significant driver of carrier cloud until after 2022, which means that even when 5G NSA and 5G/FTTN are deployed at significant levels, IoT isn’t doing much to move things beyond those two phase-one initiatives. It’s not until 2024 that IoT drives carrier cloud as strongly as video/advertising to streaming users.
That’s bad news for the media and pundits who think otherwise, and perhaps for some of the mobile-specific network vendor giants, but in an overall infrastructure sense it really won’t hurt much. Access and metro fiber will be driven by video far more than anything else. Carrier cloud, likewise. If video demand is fully exploited by operators, most of the edge hosting, fiber deployments, and even function hosting that people dream of will still come along, just for different reasons and in subtly different forms. “Carrier cloud”, for example, will focus “NFV” in a strict sense at the edge and in business services, but “cloud hosting” of network features will be driven along by advertising and video.
I think 5G, even 5G Core will deploy, eventually. The important truth is that while it will, it’s not a direct driver of the near-term changes in infrastructure, just a driver of a new RAN and a new last-mile broadband delivery mechanism. Some operators will retain a strong 5G linkage because it’s convenient for them to use that to build consensus internally and link to something with good ink, but there are plenty of opportunities for vendors having little or nothing to do with 5G to play a big role and make big gains in the next three years.