In September 2012, NTT Japan demonstrated a single fiber cable that was able to transfer 1 per second (10 bits/s) over a distance of 50 kilometers. Although larger cables are available, the highest strand-count single-mode fiber cable commonly manufactured is the 864-count, consisting of 36 ribbons each containing 24 strands of fiber. These high fiber count cables are used in, and as distribution cables in and networks. Modern fiber-optic communication systems generally include optical transmitters that convert electrical signals into optical signals, to carry the signal, optical amplifiers, and optical receivers to convert the signal back into an electrical signal. The information transmitted is typically generated by computers or.