5G Needs Fiber

I am finally starting to see an acknowledgement by the cellular industry that 5G implementation is going to require fiber – a lot of fiber. For the last year or so the industry press – prompted by misleading press releases from the wireless companies – made it sound like wireless was our future and that there would soon not be any need for building more wires.

As always, when there is talk about 5G there is a need to make sure which 5G we are talking about, because there are two distinct 5G technologies on the horizon. One is high-speed wireless loops send directly to homes and businesses as a replacement for a wired broadband connection. The other is 5G cellular providing bandwidth to our cellphones.

It’s interesting to see the term 5G being used for a wireless microwave connection to a home or business. For the past twenty years this same technology has been referred to as wireless local loop, but in the broadband world the term 5G has marketing cachet. Interestingly, a lot of these high-speed data connections won’t even be using the 5G standards and could just as easily be transmitting the signals using Ethernet or some other transmission protocol. But the marketing folks have declared that everything that uses the millimeter wave spectrum will be deemed 5G, and so it shall be.

These fixed broadband connections are going to require a lot of fiber close-by to customers. The current millimeter radios are capable of deliver speeds up to a gigabit on a point-to-point microwave basis. And this means that every 5G millimeter wave transmitter needs to be fiber fed if there is any desire to offer gigabit-like speeds at the customer end. You can’t use a 1-gigabit wireless backhaul to feed multiple gigabit transmitters, and thus fiber is the only way to get the desired speeds to the end locations.

The amount of fiber needed for this application is going to depend upon the specific way the network is being deployed. Right now the predominant early use for this technology is to use the millimeter wave radios to serve an entire apartment building. That means putting one receiver on the apartment roof and somehow distributing the signal through the building. This kind of configuration requires fiber only to those tall towers or rooftops used to beam a signal to nearby apartment buildings. Most urban areas already have the fiber to tall structures to support this kind of network.

But for the millimeter technology to bring gigabit speeds everywhere it is going to mean bringing fiber much closer to the customer. For example, the original Starry business plan in Boston had customers receiving the wireless signal through a window, and that means having numerous transmitters around a neighborhood so that a given apartment or business can see one of them. This kind of network configuration will require more fiber than the rooftop-only network.

But Google, AT&T and Verizon are all talking about using millimeter wave radios to bring broadband directly into homes. That kind of network is going to require even more fiber since a transmitter is going to need a clear shot near to street-level to see a given home. I look around my own downtown neighborhood and can see that one or two transmitters would only reach a fraction of homes and that it would take a pole-mounted transmitter in front of homes to do what these companies are promising. And those transmitters on poles are going to need to be fiber-fed if they want to deliver gigabit broadband.

Verizon seems to understand this and they have recently talked about needing a ‘fiber-rich’ environment to deploy 5G. The company has committed to building a lot of fiber to support this coming business plan.

But, as always, there is a flip side to this. These companies are only going to deploy these fast wireless loops in neighborhoods that already have fiber or in places where it makes economic sense to build it. And this is going to mean cherry-picking – the same as the big ISPs do today. They are not going to build the fiber in neighborhoods where they don’t foresee enough demand for the wireless broadband. They won’t build in neighborhoods where the fiber construction costs are too high. One only has to look at the hodgepodge Verizon FiOS fiber network to see what this is going to look like. There will be homes and businesses offered the new fast wireless loops while a block or two away there will be no use of the technology. Verizon has already created fiber haves and have-nots due to the way they built FiOS and 5G wireless loops are going to follow the same pattern.

I think the big ISPs have convinced politicians that they will be solving all future broadband problems with 5G, just as they made similar promises in the past with other broadband technologies. But let’s face it – money talks and these ISPs are only going to deploy 5G / fiber networks where they can make their desired returns.

And that means no 5G in poorer neighborhoods. It might mean little or limited 5G in neighborhoods with terrain or other similar issues. And it certainly means no 5G in rural America because the cost to build a 5G network is basically the same as building a landline fiber network – it’s not going to happen, at least not by the big ISPs.

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