POWER-EFFICIENT LAYOUT OF A FIBEROPTIC MULTISTAR THAT PERMITS LOG(2) N CONCURRENT BASEBAND TRANSMISSIONS AMONG N STATIONS

A passive, single-hop, fiber-optic interconnection among N stations, e ach with two transmitters and one receiver, and a round-robin transmis sion schedule for it, which jointly permit log2 N concurrent noninterf ering transmissions on a single wavelength, has recently been describe d. This is a substantial improvement over the previously known limit o f two concurrent transmissions, but the layout of this interconnection poses a challenge both in terms of wiring complexity and path loss. I n this paper, a power-efficient implementation of this interconnection using several stages of balanced fiber-optic star couplers is present ed. With lossless components, path loss is N, the same as a single-sta r interconnection that permits only a single transmission at a time. C onsequently, the high degree of parallelism translates into higher cap acity. The required number of (2 x 2) star couplers is also very simil ar to that required for implementing a single N x X) star.