This paper proposes a novel and simply configured broad-band optical access network that uses coherence multiplexing (CM) and half-duplex bidirectional transmission. It allows the on-demand use of broad bandwidth on existing fiber-to-the-home (FTTH) access lines. The design of the proposed CM network considers degradation factors in CM systems. This paper introduces two analyses. The first one is a numerical simulation to optimize the tradeoff between available user number and fiber dispersion degradation, and the second estimates acceptable access-line loss in the network. These analyses show that 16 users 100 Mb/s (or 12 users 155 Mb/s) bandwidth is possible on a standard single-mode fiber access line whose loss and length are under 9 dB and 10 km (and 7 km), respectively. The feasibility and scalability of the proposed network are verified by an experiment in which eight-channel 155-Mb/s half-duplex optical packet transmission is successfully demonstrated on a 7-km standard fiber access line with bit error rates better than 1 10-9. This study shows that the capacity of existing FTTH access lines that employ star couplers can be significantly enhanced.
Jun-ichi Kani, Katsumi Iwatsuki, Noboru Takachio, and Nobuo Fujii, "A Simple Broad-Band Coherence Multiplexed Optical Access Network and Its Scalability," J. Lightwave Technol. 19, 456- (2001)