A Closer Look at Dark Fiber
Basically, dark fiber is unused fiber optic cable. When optical fiber is in use, the data is sent through in forms of light pulses and this is referred to as lit fiber. But when the cable is not in use, there are no light pulses being sent and thus it is referred to as dark fiber.
But why are there unused cables you may wonder? In most cases, when a company goes out to lay this cable, they lay more than is needed to eliminate the necessity of returning to the same location and adding more cable. The labor cost of installing the cable is very high as there is a lot of planning and networking to be done as well as physical labor. So to eliminate unnecessary labor costs, laying more than is necessary is done in a lot of situations.
And because of the increase in technology since the 1990's, the amount of data that can be sent through these cables has increased dramatically. In doing so, it has reduced the need for more fiber optic cable causing an oversupply. Many telecommunication companies find themselves with more cable than they need or can use, and that leaves the cable unused and 'dark'.
Before this oversupply no one sold it. They held onto it for dear life as they considered it a core asset to the company. But now, with all the extra cable that is now lying around, many companies now sell or lease out to individuals and companies who may want an optical connection in their own locations or areas.
In the past the cost of this fiber optic cable was very expensive leaving most companies unable to purchase their own so they leased it. Today's oversupply has not made it more affordable, and the leasers are now opting to become the owners and buying their own.
It has been noted that every nine months the amount of data that can be sent through fiber cable is doubled, and because of that the cost decreases by half every nine months, excluding the cost of labor. That adds to the still a large amount of dark fiber out there just waiting to be used. The advancement of technology can create new possibilities on what that will be used for in the future and how it will make your life easier.