Fiber optic technology has been used commercially for around 25 years, though the concept is over a century old. It is now used for virtually all long distance telecommunications networks and many other applications due to its ability to transmit more data over longer distances with less interference than copper wire. While initially seen as expensive and difficult to work with, fiber optic cable has become cheaper than alternatives like copper and easier to install and test with equipment costs under $1000. It is now the dominant cable for most telecommunications uses both inside and outside of buildings.