A 5G Status Report
Few technologies are expected to have as big an impact as 5G—the next generation wireless broadband connection standard—and now that we’ve finally started seeing the first 5G-enabled devices and real-world deployments, it’s worth taking a look at where things currently stand and how they’re likely to evolve.
Fortunately, I’m now in a much stronger position to do that as the result of two different 5G-focused events I attended last week. Qualcomm’s 5G Workshop at their headquarters in San Diego emphasized core 5G technologies and the work that the company has done to evolve and integrate those technologies into semiconductor-based components. Specifically, they highlighted their work on 5G modems, RF (radio frequency) transceivers, RF front ends for fine tuning the raw radio signals, and systems that integrate all three components into complete solutions. The 5G Americas analyst event in Dallas (TX) provided the telco carriers’ and network infrastructure equipment companies’ angle on the status of today’s 5G networks throughout the US and Latin America. It also included a session with FCC commissioner Michael O’Reilly that dove into the hot topic of radio frequency spectrum issues in the US.
The two events dovetailed nicely and offered an interesting and comprehensive perspective on today’s 5G realities. What became clear is that although 5G will eventually enable a whole wealth of new applications and possibilities, for the near-term, it’s primarily focused on faster cellular networks for smartphones, or what the industry likes to call enhanced mobile broadband (eMBB). Within that world of faster 5G cellular networks, there are two very important and widely recognized sub-groups that are divided by the different radio frequencies within which they each operate: millimeter wave frequencies (typically 24 GHz and higher—so named because their wavelengths are measured in single millimeters) and those collectively referred to as sub-6, shorthand for frequencies below 6 GHz. (As a point of reference, all current 4G LTE radio transmissions are done at frequencies below 3 GHz.)
Though it might seem a bit arcane, the distinction between frequencies is an extremely important one, because it has a huge impact on both the type of 5G services that will be available and the equipment necessary to enable them. Basically, millimeter wave offers very fast performance, but only over short distances and within certain environments. Conversely, sub-6 frequencies allow wider coverage, but at slower speeds. To make either of them work, you need network equipment that can transmit those frequencies and devices that are tuned to receive those frequencies. While that seems straightforward, the devil is in the details, and there are a wide variety of factors that can impact the ability for these devices and services to function properly and effectively. For example, just because a given smartphone supports some millimeter wave frequencies doesn’t mean it will work with the millimeter wave frequencies used by a given carrier—and the same is true for sub-6 GHz support. Bottom line? There’s a lot more for people to learn about the different types of 5G than has ever been the case with other wireless network generation transitions.
Just to complicate things a bit more, one of the more interesting take-aways from the two events is that there’s actually a third-group of frequencies that’s becoming a critical factor for 5G deployments in many countries around the world—but is still waiting to be deployed in the US. The C-Band frequencies (in telecommunications parlance, typically the frequencies from 3.5 GHz to 4.2 GHz), though technically part of the sub-6 group, offer what many consider to be a very useful compromise of both better performance and wider coverage than other frequency options above and below that range. In the US, the problem is that this set of frequencies (which happen to measure in the single centimeter range, though that does not seem to be the origin of the C-band name) is not currently available for use by telecom carriers. Right now, they’re being used for applications in defense and private industry, but as part of its spectrum modernization and evolution process, the FCC is expected to open up the frequencies and auction them off to interested parties like the major telcos in 2020.
Another interesting insight from the two events is that there are some important differences between the theory of what a technology can do and the reality of how it gets deployed. In the case of millimeter wave, for example, Qualcomm showed some impressive (though admittedly indoor) demos of how the technology can be used in more than just line-of-sight applications. The initial concern around this technology was that you needed to have a direct view from where you were standing with a smartphone to a millimeter wave-equipped cell tower in order to get the fastest possible speeds. With the Qualcomm demo, however, people were able to walk behind walls, and even into conference rooms, and still maintain the download speed benefits of millimeter wave, thanks to reflections off walls and glass. When asked why early real-world tests of 5G devices didn’t reflect this, the company essentially said that the early networks weren’t as dense as they needed to be and weren’t configured as well as they could be. Carrier representatives and network equipment makers at 5G Americas, however, countered that the reality of outdoor interference from existing 4G networks and the strength of those signals meant that—at least for the near term—real-world millimeter wave performance will be limited to line-of-sight situations.
An interesting takeaway from the demo, and the subsequent conversations, is that millimeter wave-based 5G access points could prove to be a very effective alternative to WiFi in certain indoor environments. Faster download speeds and wider coverage mean that fewer 5G small cells would have to be deployed than WiFi access points in a given building, potentially leading to lower management costs. Plus, technologies have been developed to create private 5G networks. As a result, I think millimeter wave-based 5G indoor private networks could prove to be one of the sleeper hits of this new technology.
Even though most of the current 5G efforts are focused on speeding up cellular connections, it became clear at both events that there are, in fact, a lot of interesting applications still to come in industrial environments, automotive applications, and more. Another important point that was emphasized at both events is that the initial launch of 5G is not the end of the technological development process, but just the beginning. As with previous cellular network generations, the advancements related to 5G will come in chunks roughly every 18-24 months. These developments are driven by the 3GPP (3rd Generation Partnership Project—a worldwide telecom industry standards group originally formed to create standards for 3G) and their release documents. The initial 5G launch was based on Release 15. However, Release 16 is expected to be finalized in January of 2020, and that will enable a whole other set of capabilities, all under the 5G umbrella. In addition, a great deal of work has already been done to start defining the specifications for Release 17, which is expected sometime in 2022.
The bottom line is that we’re still in the very early stages of what’s expected to be a decade-long evolution of technology and applications associated with 5G. Initial efforts are focused on faster speeds, and despite some early hiccups, excellent progress is being made with much more to come in 2020. The two conferences made it clear that the technologies underpinning next generation wireless networks are very complicated ones, but they’re also very powerful ones that, before we know it, are likely to bring us exciting new applications that we’ve yet to even imagine.