Your broadband customers are using more bandwidth every year and their media distribution hub can easily handle video, play games, and power their smart homes. Where does all of this bandwidth come from, and when is usage going to reach capacity?

Extra bandwidth is available through dark fiber, but how much of it will be available to your residential customers has yet to be seen.

Dark fiber is the term for fiber optic cable that is currently not in use. When you think about it, the term makes sense as fiber transmits data using light waves. If no data is being transmitted, no light travels along the cable and they are dark.

The amount of data that can pass through fiber optic cables doubles about every nine months. Click To Tweet

There are large amounts of dark fiber because the companies that first built fiber infrastructure installed more cable than what is needed for current or near-term bandwidth requirements. Since then, the technology for sending data has improved, allowing more data to travel on a single strand of fiber.

Dark fiber can be leased to clients who then use the lines to create a separate wide-area network. While the fiber is now not technically dark, it has yet to be integrated with the rest of the provider’s network.

DWDM technology slows demand for cable

The amount of data that can pass through fiber optic cables doubles about every nine months. Part of that increase is due to new techniques such as dense wavelength division multiplexing (DWDM). DWDM sends data along different wavelengths or channels, allowing more data to travel along a single strand of fiber. This technique has slowed the demand for cable, which means there is extra infrastructure available for lease.

When an organization orders dark fiber, it’s assigned its own wavelength, also known as a virtual fiber. Dark fiber provides organizations with high bandwidth internet at a reduced cost. It also means large organizations aren’t sharing the network with residential users, creating more virtual space for everyone.

Who is using dark fiber?

Many organizations with large bandwidth requirements  are turning to dark fiber. Google, for example, has been buying dark fiber since 2005. Facebook and Microsoft use it as well.

Municipalities are also using dark fiber. The City of Kelowna in British Columbia has installed about 16 kilometers of dark fiber for use by city facilities. The city is also offering dark fiber to local businesses as a way to encourage tech investment in the area.  Dark fiber is part of the strategic plan for broadband in Canmore, Alberta, and the cities of Durango and Centennial, in Colorado, already have dark fiber networks.

Globally, access to dark fiber remains somewhat limited, and there are concerns that this will curtail the pace of connectivity. In the UK, for example, a dark fiber controversy has been brewing for years. In August 2017, BT Openreach, the company that runs all of Britain’s fiber optic internet, closed off access to its dark fiber. Many organizations, particularly mobile operators, objected to this. But others have looked for other options. SSE Enterprise, a telecom and utilities company, has opted to lay its own dark fiber in the sewers of London.

Dark fiber is becoming more affordable, which means it’s a viable option for smaller organizations as well. The market is growing, and is projected to be worth USD$11 billion by 2026, with North America making up about 40% of that market.

While it’s unlikely your residential customers will be using dark fiber to power their smart homes any time soon, it’s an important part of the broadband landscape. And as bandwidth demands increase, its importance will grow too.