Media converters (Dyden Corporation) include ultra-long distance products for 125-km transmission at 100 M_ and 100-km transmission at 1G_, and the GIIE Series with which transmission is possible up to 2 km using MMF. This lineup even includes chassis accessories.
URL: http://www.dyden.jp/network/mediaconverter/

The "ACLC" high-speed, coaxial modem (Sumitomo Electric) enables up to 200-Mbps communication using existing TV coaxial cables. Because new infrastructure maintenance is unnecessary, networks can be constructed at a low price and in a short time.