I had a conversation last week with somebody who firmly believes that our broadband future is going to be 100% mobile wireless. He works for a big national software company that you would recognize and he says the company believes that the future of broadband will be wireless and they are migrating all of their software applications to work on cellphones. If you have been reading my blog you know I take almost the opposite view, but there are strong proponents of a wireless future, and it’s a topic worth continually revisiting.

Certainly we are doing more and more things by cellphone. But I think those that view future broadband as mobile are concentrating on faster mobile data speeds but are ignoring the underlying overall data capacity of cellular networks. I still think that our future is going to become even more reliant on fiber in order to handle the big volumes of bandwidth we will all need. This doesn’t mean that I don’t love cellphone data – but I think it’s a complement for landline broadband and not an equivalent substitute. Cellphone networks have major limitations and they are not going to be able to keep up with our need for bandwidth capacity. Even today the vast majority of cellphone data is handed off to landline networks through WiFi. And in my mind that just makes a cellphone into another terminal on your landline network.

Almost everybody understands the difference in quality between using your cellphone in your home using WiFi versus doing the same tasks using only the cellular network. I largely use my cellphone for reading news articles. And while this is a lot lighter application than watching video, I find that I usually have problems opening articles on the web when I’m out of the house. Today’s 4G speeds are still pretty poor and the national average download speed is reported to be just over 7 Mbps.

I think all of the folks who think cellphones are the future are counting on 5G to make a huge difference. But as I’ve written many times, it will be at least a decade before we see a mature 5G cellular network – and even then the speeds are not likely to be hugely faster than the 4G specification today. 5G is really intended to increase the stability of broadband connections (less dropped calls) and the number of connections (able to connect to a lot of IoT devices). The 5G specifications are not even shooting for at a huge speed increase, with the specification calling for 100 Mbps download cellular speeds, which translates into an average of perhaps 50 Mbps connections for all of the customers within a cell site. Interestingly, that’s the same target speed of the 4G specification.

And those greater future speeds sounds great. Since a cellphone connection by definition is for one user, a faster speed means that a cellular connection will support a 4K video stream eventually. But what this argument ignores is that a home a decade from now is going to be packed with devices wanting to make simultaneous connections to the Internet. It is the accumulated volume of usage from all of those devices that is going to add up to huge broadband demand for homes.

Already today homes are packed with broadband hungry devices. We have smart TVs, cellphones, laptops, desktops and tablets all wanting to connect to the network. We have other bandwidth hungry applications like gaming boxes and surveillance cameras. More and more of us are cutting the cord and watching video online. And then there are going to piles of new devices with smaller broadband demands, but which in total will add up to significant bandwidth. Further, a lot of applications we use are now in the cloud. My home uses a lot of bandwidth every day just backing up my data files, connecting to software in the cloud, making VoIP calls, and automatically updating software and apps.

I’ve touted a statistic many times that you might be tired of hearing, but I think it’s at the heart of the matter. The amount of bandwidth used by homes has been doubling every three years since 1980, and there is no end in sight to that trend. Already today a 4G connection is inadequate to support the average home. If you don’t think that’s true, talk to the homes now using AT&T’s fixed LTE connections that deliver 10 Mbps. That kind of speed is not adequate today to provide enough bandwidth to use the many broadband services I discussed above. Cellular connections are already too slow today to provide a reasonable home broadband, even as AT&T is planning to foist these connections on millions of rural homes.

There is no reason to think that 5G will be able top satisfy the total broadband needs of a home. The only way it might do that is if we end up in a world where we have to buy a small cellular subscription for every device in our home – I know I would prefer to instead connect all of my devices to WiFi to avoid such fees. Yes, 5G will be faster, but a dozen years from now when 5G is finally a mature cellular technology, homes will need a lot more bandwidth and a 5G connections then will feel just as inadequate then as 4G feels today.

Unless we get to a future point where the electronics get so cheap that there will be a ‘cell site’ for every few homes, then it’s hard to figure that cellular can ever be a true substitute for landline broadband. And even if such a technology develops you still have to ask if it would make any sense to deploy. Those small cell sites are largely going to have to be fiber fed to deliver the needed bandwidth and backhaul. And in that case small cell sites might not be any cheaper than fiber directly to the premise, especially when considering the lifecycle costs of the cell site electronics. Even if we end up with that kind of network – it’s would not really be a cellular network as much as it would be using wireless loops as the last few feet of a landline network – something that for years we have called fiber-to-the-curb. Such a network would still require us to build fiber almost everywhere.