3 Big Challenges For 5G

The general assumption is that we will all be walking around with 5G phones in our pockets someday, but 5G devices may look more like a home router, a car, or maybe even a tablet than a smart phone.

There are three main problems that need to be solved here. The big one is coverage, and that gets confusing because it depends on which version of 5G people are talking about. There are at least two different steps in the rollout of 5G, each at a different frequency. The first implementations may look more like 4.5G because they will operate in the sub-6GHz band. While this will improve Internet speeds, it won’t be a game-changing boost.

That will come with millimeter-wave technology, which can scale to 300GHz. The problem with millimeter wave, though, is that signals don’t travel very far. They don’t go through walls, windows, or crowds of people. They’re basically line-of-sight connections, requiring a massive number of small cells and repeaters in densely packed areas.

Beam-forming technology will solve some of these problems, because it can triangulate signals. But the edge device has to search for those signals. As soon as something or someone interrupts one of those signals, it has to search for another signal to replace it. The result is these devices will burn through batteries much faster than a 4G LTE phone in a poor reception area.

For some devices that might not matter. They can turn on, search for a signal, exchange data, and shut down. For streaming video or audio, that clearly doesn’t work.

That leads to the second problem, which is how to make batteries last longer. There are a couple different options here. One is new battery technology, and there is work underway in universities and startups around the globe both to increase how much energy can be packed into a battery and how quickly they can be recharged. Other technologies exist, such as sodium-ion, but it’s not clear at this point how stable they are. And given the number of fires caused by overheating Li-ion batteries in airplanes, laptops and cell phones, the market will be cautious about adopting new battery technology for liability reasons.

Without longer battery life, 5G’s usefulness still will prove significant in plenty of different places. In an office building or on a home network, for example, a 5G wireless network would provide significantly better wireless speed for many more devices. In rural areas, one tower might serve a much wider area with better coverage using a series of repeaters than many towers do today. And there will be many new applications in places, such as smart cities, where enormous bandwidth was never an option.

But how this bandwidth gets utilized will change. And this leads to the third problem. In order to take advantage of 5G with spotty coverage with reduced battery life, devices will have to get much larger, or system architectures will have to become remarkably more energy efficient. So while bandwidth will be virtually unlimited in comparison to today’s standards, the question is for what purpose. There will certainly be more devices generating more and different kinds of data, but where that data gets processed and how it gets partitioned may take years to figure out.

The age of 5G is just beginning, and like any new technology, it’s not obvious how it ultimately will be used. What is clear, though, significant changes will be required in multiple areas for edge devices to take full advantage of 5G. Creating 5G network infrastructure is an important step, but it’s only one piece of a very large puzzle.