With MWC just around the corner and a flood of 5G stuff inevitable, this is the time to ask two questions. First, what is really happening in the 5G space? Second, when can we expect to see a complete 5G story deploy? Those aren’t easy questions to answer in MWC discussions, particularly when the emphasis at trade shows isn’t likely to be “reality”.
The biggest barrier to a realistic view of 5G is the lack of a concrete definition of what 5G is. There are really two broad pieces to 5G. One is the 5G New Radio stuff, and the other is the changes to mobile infrastructure that accompany, but don’t necessarily have to accompany, the 5G NR stuff. We can roughly map this to what’s being called 5G Core. Originally the two were considered to be joined at the hip, but the 3GPP adopted a new work plan in 2017 called “NSA” for “Non-Stand Alone”. This quirky name means 5G NR without 5G core, and that’s the key point to addressing our questions.
Everyone agrees that mobile services need more capacity and more bandwidth per user. That’s particularly true if operators want to use a combination of fiber-to-the-node (FTTN) and cellular radio to create what look like wireline broadband services. All of the 5G changes relating to the cellular radio network itself are part of NR. From NR, you have three possible pathways forward.
Pathway one is to meld millimeter-wave NR with FTTN to support what’s essentially a “local 5G” network that would serve not mobile users but wireline broadband users. This model of 5G doesn’t need mobility management (fiber nodes aren’t migrating, and fixed “wireline” terminations aren’t either) or any of the handset roaming and registration features. This form of 5G is already being tested, and there will surely be real if limited deployments even in 2018.
Pathway two is 5G NSA (non-standalone, remember?). This route says that you upgrade the RAN, where probably 95% of the 5G benefits come from anyway, and continue to use the mobility management and handset registration technologies of 4G, meaning IMS and EPC. This changes out handsets to use 5G frequencies and radio formats, but leaves the rest of mobile infrastructure pretty much intact. Since most users won’t toss handsets just to migrate to 5G and since 4GLTE compatibility is a requirement for 5G anyway, this gives you most of what 5G promises at the lowest possible impact. Some 5G NSA deployments are certain for 2019, and possible even in late 2018.
Pathway three is true 5G, the combination of 5G NR and Core. This is the 5G of dreams for vendors, the vision that includes stuff like network slicing, NFV integration, and all sorts of other bells and whistles that someone thinks would be exciting. This is also the 5G that may never come about at all, and that’s the nub of the issue with 5G discussions. Do we talk about the “standard” of 5G that always includes both NR and Core, or do we talk about NSA, which includes only NR and which is almost certain to deploy?
In my view, the 5G standard is a combination of an attempt to address a plausible pathway for wireless evolution and the typical overthinking and overpromotion of our networking marketplace. If you assumed that we were going to see billions of IoT devices connected via the cellular network, and you assumed that we were going to have hundreds of different, independent, virtual cellular networks to support hundreds of different applications, and if you assume that we were going to demand free roaming between WiFi, satellite, wireline, and wireless calls, then perhaps you need full 5G. Can we make the assumptions? Not now, but standards have to prepare for the future and so it’s not unreasonable to talk about 5G in full standards form, as an evolutionary path that has to be justified by tangible market opportunity. Otherwise it’s a pie in the sky.
5G NSA is proof of that. The vendors involved were supporters of the NSA approach, and surely they would have been more reserved had it been likely that holding out for full 5G was an option. The vendors almost certainly realized that if operators were presented with a 5G all-or-nothing, they’d have selected the “nothing” option, or forced an NSA-like approach down the line. Sure, vendors would love a mobile infrastructure revolution, but not if it’s a low-probability outcome on a high-stakes game where real radio-network dollars are at stake.
What this means for 5G is that NSA is the real path, and that all the Core stuff is fluffery that will have to be justified by real opportunities. Here, the facts are IMHO quite clear; there won’t be any of those real opportunities in the near term. If there’s a 5G core evolution, it’s probably not coming until after 2022, and even then, we’d have to see some decisive progress on the justification front, not on the standards front.
There are two realistic drivers to a broader 5G deployment, rapid IoT adoption that’s dependent on cellular-linked IoT elements, and a shift to streaming video rather than linear TV. The first of the two is the most glamorous and least likely, so we’ll look at it first.
Almost all the growth in “IoT” has been through the addition of WiFi-linked sensors in the home. This has no impact whatsoever on cellular needs or opportunity, and it creates zero additional 5G justification. What you’d need for 5G stimulus is a bunch of new sensors that are directly connected to the cellular network, and while there are various 5G radio suggestions for this, and there are missions that could credibly consume that configuration, the business case behind them hasn’t been acceptable up to now.
Apart from the “soft” question of public policy and personal privacy that open sensors raise, there’s the simple point of ROI. Remember, anything that’s directly networked, rather than behind the implicit firewall of home-style NAT, would have to be secured. The stuff would have to be powered, maintained, etc. Private companies installing IoT sensors would have to wonder how they’d pay back on the cost. Would cities be willing to fund initiatives to make all traffic lights smart? It would depend on how much of a case could be made for a result that would improve traffic conditions and the driving experience. And how gutsy politicians would be that the results would be delivered, because if they weren’t the next election wouldn’t be pretty.
The video story is complicated, but plausible. We already know that streaming on-demand video demands effective content delivery networking, places to cache popular material to avoid over-consuming network resources on long delivery paths. What about live TV? Imagine a bunch of mobile devices, and also wireline-via-FTTN/5G stuff, streaming live TV. Would you want to pull each stream from a program source, even one within a metro area? Would you want to cache the material locally, use multicasting, or what?
How much have you read about live TV streaming as a 5G driver? I know I’m not exactly bombarded with material, I don’t hear operators clamoring for it, I don’t see vendors pushing solutions. But if you want to see 5G in anything other than the NSA version, that’s what you should be looking for in Barcelona. Don’t hold your breath, though. As I’m sure most of you know, relevance to real issues is not a trade show strong point.