Fiber to the home (FTTH) is the focus of one of the biggest projects going on in fiber optics today. With the passage of the Infrastructure Investment and Jobs Act, $43 billion from the Broadband Equity, Access and Deployment Program will go to qualified project recipients to connect underserved residents.

As president of the Fiber Optic Association (FOA), I am happy to hear that and heartily concur. Fiber is the best way to provide broadband today and the only way to accommodate the expected growth in bandwidth. What is not as often considered is exactly how to design fiber optic networks to deal with future bandwidth projections.

Today, most FTTH projects use gigabit passive optical network (GPON) technology. A single GPON port on an optical line terminal at a service provider’s head end can connect 32 or 64 users sharing a single fiber through a PON splitter, although most networks only connect about two-thirds of that number for adding users in the future.

Today, that same fiber network can support 10G PONs for higher bandwidth and 128 or more users. Research and development is ongoing for 50G–100G PONs that can serve 1,000-plus users, but there are questions on whether the shared fiber network for PONs would be capable of handling growing bandwidth needs.

Cable versus fiber

Premises cabling users living through four or five generations of UTP cabling would not be surprised at it becoming obsolete, but telecom companies expect a lifetime of 20–40 years for their fiber optic cable plant. When they were installing fiber 30 years ago, networks ran at under 1G speed. Most of those fibers today operate at 10G, some at 100G. Today’s fibers are capable of terabit speeds (1,000G) and at more than 100 wavelengths. That’s why we consider fiber lifetimes to be so long.

For the last five years, FOA has been working with a successful entrepreneur in wireless who thinks along these lines. When Jack Demers first visited me at FOA, he wanted to understand fiber optics and FTTH. At that point, we already had helped Verizon get FiOS FTTH going and we had several DIY FTTH projects in the works. We discussed some present and future scenarios that day, and he soon started a company to build fiber networks.

Recently, the fiber optic company that Demers started finished its first city network in Solana Beach, Calif., creating the world’s first Terabit City. Just like Chattanooga, Tenn., is considered the first Gigabit City for its offer of 1G PON service to all its customers, Solana Beach is the first city fibered to allow 1T (1 terabit/s) to every user.

The city of the future

What’s different about the network in Solana Beach? Every user has a dedicated fiber direct from the head end to them. In this case, a "user" can be an ISP or CATV customer, city office, traffic light, utility pole with a 5G antenna and more. The network has over 30,000 fibers for a town with about 6,000 households.

Secondly, the network is open-access. Demers’ company is not a service provider; it owns the fiber and leases fiber connectivity to any service provider.

An ISP is already on board, offering GPON service, but its electronics and PON splitters are all located at the company’s head end. To add a user, it just needs to connect a patchcord to the fiber going to that user. Other service providers can co-locate and connect their users. Wireless companies can connect their antennae. The city can connect their traffic signals and video cameras. Service changes do not require any changes to the network once the user is connected.

When I describe this, most people ask, "Isn’t all that fiber prohibitively expensive?" Not at all. Fiber is really cheap; installing it is the expensive part. When my friend’s company used microtrenching to cut costs and minimize disruption in the city during construction, they installed six microducts, each sized for blowing in a 288-fiber microcable. In most areas, only one cable was installed, providing expansion to 1,728 fibers along that route when needed. That’s the "dig once" method, another aspect of designing a fiber optic network for the future.

Solana Beach is ready for terabit networks, 1,000 times faster than needed to be state-of-the-art today and ready for plenty of future growth. Higher bandwidth will be provided with electronics upgrades at the head end. Additional service providers need only move their equipment into the head end and connect their users. When needed, additional cables can be installed in current ducts with minimal effort and cost.

That’s what planning for the future means. And Demers’ company is getting ready to start its next Terabit City in Folsom, Calif.