Latest / The 5G Podcast with Fexingo: Wireless Networks, Carriers, and Mobile Infrastructure / How 5G Is Facing a Broadband Capacity Crunch
Transcript
- Lucas: There's a number that's been stuck in my head this week. Cisco's latest Visual Networking Index — even though they sunset that report, the last one from 2023 projected that global mobile data traffic would hit something like 500 exabytes per year by 2026. We're basically there now, in May 2026, and the growth curve hasn't flattened. The thing is, 5G was supposed to be the answer to capacity, but the easy gains are behind us. Luna: So the network is getting fuller faster than we expected? Lucas: Exactly. Early 5G deployments used mid-band spectrum — C-band, 3.5 gigahertz in Europe, that sort of thing — and carriers got a nice 10x or 20x boost over 4G. But that was a one-time jump. Now we're adding more users, more devices, more video streaming, and every new application from connected cars to augmented reality chews through bits. The spectral efficiency improvements from 5G alone aren't enough to keep up. Luna: I remember reading that 5G's peak spectral efficiency is something like 30 bits per second per hertz, while 4G is around 15. That's a doubling, not a tenfold leap. Lucas: Right. And in real-world deployments, you rarely hit peak. So the carriers are staring at a capacity crunch within the next couple of years unless they do something else. There are really three levers they can pull: more spectrum, more cells, or smarter antennas. Let's take them one at a time. Luna: Start with spectrum. Isn't that the most obvious? Just buy more airwaves. Lucas: It is, but it's getting harder. The low-band spectrum below 1 gigahertz is almost fully allocated. Mid-band is going fast — the C-band auctions in the US and Europe wrapped up a couple of years ago. What's left is millimeter wave, above 24 gigahertz, which has tons of bandwidth but terrible propagation. It doesn't go through walls, it doesn't go far. So carriers are using it mostly for fixed wireless access or dense urban hotspots. Luna: There's also the option of refarming older spectrum. T-Mobile, for instance, has been repurposing its 600 megahertz from the old TV band for 5G. That gives coverage but not capacity. Lucas: Exactly. Low-band is great for range, but narrow channels. So the capacity fix really has to come from the other two levers: densification and antenna technology. Densification means putting more cells closer together — small cells on lampposts, building facades, indoor venues. That's expensive. Each small cell needs backhaul, power, permits. Luna: And not every city is eager to have thousands of little boxes on every streetlight. There's been pushback in places like San Francisco and some European cities on visual clutter and health concerns, even though the science doesn't show risks. Lucas: Right. So carriers are also looking at smarter antennas — massive MIMO, which stands for multiple input multiple output. Instead of the usual two or four antennas, a massive MIMO array might have 64 or 128 antenna elements. It forms narrow beams to each user, so the same spectrum can be reused within the same cell. That increases capacity by a factor of three to five. Luna: And that's already being deployed. Verizon and AT&T have been rolling out massive MIMO on their C-band gear for the last couple of years. But there's a catch, right? Lucas: The catch is that massive MIMO works best when you have a lot of active users in a small area. In a stadium or a downtown core, it's fantastic. In a suburban or rural setting with fewer devices, the benefit drops off. Also, the signal processing is computationally intensive, which means more power draw and more heat. So carriers have to balance where they deploy it. Luna: If today's conversation gave you something useful, here's a quick thought. This show stays ad-free because listeners like you support it directly. If you want to help keep these episodes coming, you can find us at buy me a coffee dot com slash fexingo. No pressure, just a simple way to say thanks. Lucas: Yeah, we really appreciate those who do. It lets us keep digging into topics like this without any sponsor influence. Now, back to the capacity question — there's another angle I think is worth exploring, and that's how this crunch affects enterprise private networks. Luna: Oh, interesting. Because private 5G networks are growing fast, but they lease spectrum from carriers or use shared spectrum like CBRS in the US. If the public network is congested, does that squeeze the private ones? Lucas: It can. In CBRS, the priority access license tier gives enterprises their own slice of the band, so they're protected from public congestion. But if a carrier's own network is hitting capacity, they might be less willing to lease out spectrum slices for private networks at favorable rates. We're already seeing some carriers raise prices for network slicing in the context of industrial IoT. Luna: So the capacity crunch could actually slow down the private 5G adoption we talked about in episode two. Lucas: Potentially. But it also creates an opportunity for enterprises to invest in their own small-cell infrastructure. A factory or a warehouse can deploy a dense network of indoor small cells that offload traffic from the macro network. That's happening already in German automotive plants, for example. BMW and Audi have been running private 5G on their own dedicated spectrum. Luna: Let's talk about one more lever that's often overlooked: distributed antenna systems, or DAS. Those are the networks of antennas inside large buildings, stadiums, airports. Lucas: DAS is actually a big part of the capacity solution for indoor venues, where most mobile data is consumed. A good DAS installation can multiply capacity by bringing the signal directly to the user. But DAS is expensive to install and maintain, and it's usually paid for by the building owner or a neutral host provider. Carriers love it because it offloads traffic for free. Luna: There's a trend now toward 'small cell as a service' where companies like Crown Castle or American Tower install and manage the indoor network for a monthly fee. That lowers the upfront cost for building owners. Lucas: That's a smart model. And it's going to become more common as the capacity crunch forces carriers to get every bit of efficiency they can. The bottom line is that 5G's promise of massive capacity isn't automatic — it requires significant investment in infrastructure and technology. The carriers that deploy small cells strategically, use massive MIMO where it matters, and partner with neutral hosts for indoor coverage will be the ones that manage the crunch. Luna: And the ones that don't might see their networks slow down as data demand keeps climbing. It's a race against the exabyte. Lucas: Exactly. We'll be watching how the next wave of spectrum auctions and small-cell deployments play out in the second half of 2026. It might determine who leads in 5G performance for the next few years.