Novel fiber optic telephone loop networks are disclosed. In the networks, single mode fiber optics are used for feeder and distribution segments of the loop but multimode fiber optics are used for the drops. The use of the multimode fiber optics has permitted the use of less costly optoelectronic devices....http://www.google.de/patents/US5325223?utm_source=gb-gplus-sharePatent US5325223 - Fiber optic telephone loop network
