Over recent months, the wireless industry has begun to talk more and more about 5G, the next generation of wireless technology. Verizon and AT&T have announced something of a roadmap for testing the technology here in the US and it was a major theme at the recent Mobile World Congress as well. All this seems to be happening just as people in the US finally have almost ubiquitous access to 4G, the most advanced carrier wireless technology currently available, so this may seem premature. What exactly is 5G and do we really need to start learning about a new technology already?
Understanding 4G is critical to understanding 5G
To understand 5G and all the complexities surrounding it, you first need to understand 4G and, to some extent, the other generations that came before it. These “Gs” are named for generations of mobile technology, with the first being the earliest wireless technology, 2G being digital services, 3G ushering in basic mobile broadband, and 4G finally bringing really usable mobile broadband to the masses. Each of these technologies has been represented by a set of standards which took many years to develop, formalize, and then roll out in the form of commercial networks.
Roughly ten years separated each of these generations, with 1G services being rolled commercially in the early 1980s, 2G in the early 1990s, 3G in the early 2000s, and 4G in the early 2010s. On that basis, we’re due for another generation in the early 2020s. That’s about where 5G is likely to land, but we’ll come back to that.
With regard to 4G specifically, the most important thing to understand is it’s a far more expansive set of technologies than previous generations were. What I mean is previous generations came with a set of performance specs that were pretty well defined and ultimately bounded by certain limitations. As soon as each of these generations was standardized, it was clear another generation would need to come afterwards. But that’s not as true for 4G as it was for the earlier generations. Most 4G networks today run some form of the LTE technology, but even though that technology has certain performance characteristics in its current form, there are other flavors of LTE which will deliver far higher throughput and other improved characteristics in a way that wasn’t true for the earlier generations of technology.
The need for 5G
The need for 5G then isn’t as obvious as it was in previous eras in the wireless industry. Because 4G has so much headroom in terms of performance and because it solved many of the pain points that existed in the industry before its introduction, including true broadband speeds, very low latency, and greater cost and spectral efficiency, 5G can’t simply provide more of the same on an incremental basis and still qualify as a new generation. In order to merit the name, 5G has to bring steep changes in several different characteristics, but those are harder to find. Arguably, wireless equipment vendors and carriers need 5G far more than most of their customers do.
No standards yet
As a result of all this, there actually isn’t any sort of standard definition of 5G today and it’s far from being a recognized standard. That hasn’t stopped both the equipment vendors and the carriers from talking about it as if it were, but it’s important to note that what these companies are talking about is a broad vision of what 5G could become rather than something more specific. However, most definitions put forward suggest some combination of the following characteristics:
- Very high speeds – often talked about in terms of gigabits per second versus tens or hundreds of megabits per second for 4G
- Extremely low latency – whereas 4G introduced much lower latency, 5G technology could bring single millisecond latency
- Better support for IoT deployments, including both support for very dense sensor arrays and much lower power radios so devices in the field can run for years without needing new batteries. Some conceptions of 5G also include the ability to dynamically assign bandwidth and other characteristics to different devices running on the same network
Despite these shared goals however, it’s not yet clear what the underlying wireless technology will be that delivers these results, including what spectrum might be used. Millimeter wave spectrum (higher frequency bands than those currently used for most cellular services) is considered promising for some deployments, but other versions of 5G envisage combining various different spectrum bands and technologies together. This is one of quite a number of areas where consensus has yet to emerge.
More marketing than reality today
What then to make of all the field trials and other activity that’s going on today? Well, ultimately it comes down to marketing, both on the part of the operators and their equipment suppliers. Each of these companies wants to get a head start on the competition in terms of shaping people’s views of what 5G will bring and demonstrating they’re at the forefront of the technology. There are significant downsides to all this. Introducing another term like 5G at a time when it doesn’t have a clear definition risks confusing customers, especially when many of them have barely begun to understand 4G. In addition, getting too far down the road with a particular version of 5G before standards are set risks either pursuing a dead end or fragmenting the industry. The reality is 5G standards won’t be set for some time to come and, even once they are, networks based on those standards won’t be commercially available for some time after that. As such, it’s realistic to think of 5G arriving in the real world in a way that will actually matter to customers sometime in the early 2020s, just in time to continue the pattern we outlined earlier.