Spend any time in wireless, or Technology in general, and the subject of 5G is almost certain to come up. We have written about it here (and here). The world is full of talk about fast 5G networks and all the incredible new things that 5G will unleash. A whole new Internet, they say.
Here at D2D, we like to think of ourselves as practical, nuts-and-bolts-and-antenna people. So for us, a lot of this 5G discussion strikes us a bit breathless. Yes, 5G is coming and data rates will improve, but we, the mobile industry, still have a lot of work to do. We could regale you with litanies of woe about roaming and hand-offs, or belabor the small cell backhaul density logjam. But perhaps the best example of roadblocks to 5G is much easier to grasp – Heat.
5G phones get hot. Really hot. Probably not hot enough to ignite your battery (probably), but enough to generate a definite burning sensation in your pants pockets. At Mobile World Congress in February, we spoke with an engineer from Sony who was demo’ing a phone (behind glass) that was clocking 1 Gbps speeds. Wow, fast. We asked the engineer why it was not going faster and he said “It overheats.” A good solid answer, from a nuts-and-bolts-and-antenna person. We will wager any amount that at next year’s show, no one on the floor will be as open about this problem.
The big improvement in data rates for 5G will only come with mmWave radios. This is a whole new spectrum band that allows for really high data rates (again, let’s set aside the whole densification issue for now). The trouble is that mmWave radios generate a lot of heat. To greatly oversimplify, mmWave frequencies are pretty close to microwave frequencies, as in the thing we use to reheat our lunches.
From some of our very recent industry conversations we know that the handset industry is using a tried-and-tested method for dealing with this problem – ignoring it and hoping it goes away. The whole issue strikes us as one of those issues where middle management really does not want to raise the subject with senior management who have wrapped themselves so tightly around the 5G flagpole. “Uh boss, your pants are literally on fire.”
There are other factors at play as well. We will spare you our Deep State conspiracy theories on this (Buy us a beer in Barcelona…), but there is a pretty clear disconnect in the supply chain on this topic right now.
Of course there are some solutions, but none of them are complete and they all have serious drawbacks. It turns out that the way we cool electronics has not advanced in 40 years. There are really two methods used currently to cool Things down- Fans and Dissipation.
Fans are what you think they are. Anyone who has ever opened up their desktop PC or overclocked their laptop knows what these look like. But fans have two problems: they are big and they have moving parts. Both of those require design decisions that go counter to every mobile design trend in the past 15 years.
Dissipation is just the idea of moving the heat around to hasten air cooling. In a PC, this is typified by those funny looking prong-things that sit on top of CPUs. Those things are too tall to fit inside a 10mm thick phone. So for mobiles, OEMs are looking at using ‘straws’, or copper pipes that span the length of the phone. These take up a lot of space and inserting a large conductive element (copper!) inside a phone wreaks havoc on mobile radios, (i.e. hurting data rates).
Before we can revel in the Fullness That Is 5G, the industry needs to find a solution to this problem. And that will likely mean a whole new approach to the problem.