As much as I’ve written about broadband and broadband technology, it struck me that I have never written a concise response to the question, “Why Fiber?”. Somebody asked me the question recently, and I immediately knew I had never answered the question. If you’re going to build broadband and have a choice of technologies, why is fiber the best choice?

Future-proofed. This is a word that gets tossed around the broadband industry all of the time, to the point that most people don’t stop to think about what it means. The demand for broadband has been growing at a blistering pace. At the end of the third quarter of 2020, the average US home used 384 gigabytes of data per month. That’s up from 218 gigabytes per household per month just two years earlier. That is a mind-boggling large amount of data, and most people have a hard time grasping the implications of fast growth over long periods of time. Even fiber network engineers often underestimate future demand because the growth feels unrealistic.

As a useful exercise, I invite readers to plot out that growth at a 21% pace per year—the rate that broadband has been growing since the early 1980s. The amount of bandwidth that we’re likely to use ten, twenty, and fifty years from now will dwarf today’s usage.

Fiber is the only technology that can handle the broadband demand today and for the next fifty years. You can already buy next-generation PON equipment that can deliver a symmetrical 10 Gbps data stream to a home or business. The next generation already under beta test will deliver a symmetrical 40 Gbps. The next generation after that is likely to be 80 Gbps or 100 Gbps. The only close competitor to fiber is a cable company coaxial network and the only way to future proof those networks would be to ditch the bandwidth used for TV, which is the majority of the bandwidth on a cable network. Even if cable companies are willing to ditch TV, the copper coaxial networks are already approaching the end of economic life. While there has been talk of gigabit wireless to residents (which I’ll believe when I see it), nobody has ever talked about 10 gigabit wireless.

Fiber Has Solved the Upload Problem. Anybody working or schooling from home now needs fast and reliable upload broadband. Fiber is the only technology that solves the upload needs today. Wireless can be set to have faster uploads, but doing so sacrifices download speed. Cable networks will only be able to offer symmetrical broadband with an expensive upgrade with technology that won’t be available for at least three years. The industry consensus is that cable companies will be loathed to upgrade unless forced to by competition.

Is the Easiest to Operate. Fiber networks are the easiest to operate since they transmit light instead of radio waves. Cable company and telco copper networks act like giant antennas that pick up interference. Interference from other wireless providers or from natural phenomenon is the predominant challenge of wireless technologies.

A fiber network means fewer trouble calls, fewer truck rolls, and lower labor costs. It’s far faster to troubleshoot problems in fiber networks. Fiber cables are also surprisingly strong, and fiber is often the only wire still functioning after a hurricane or ice storm.

Lower Life Cycle Costs. Fiber is clearly expensive to build, but the cost characteristics over a fifty-year time frame can make fiber the lowest-cost long-term option. Nobody knows how long fiber will last, but fiber manufactured today is far superior to fiber built a few decades ago. When fiber is installed carefully and treated well, it might well last for most of a century. Fiber electronics are likely to have to be upgraded every 10-12 years, but manufacturers are attuned to technology upgrades that allow older customer devices to remain even after an upgrade. When considering replacement costs and ongoing maintenance expenses, fiber might be the lowest-cost technology over long time frames.