Combined teletraffic-transmission analysis of a transparent space-division optical star network

The combined teletraffic-transmission analysis of a single-wavelength cell-switching all-optical local area network (LAN) with star topology is presented. The star is a multistage space-division photonic switch-that uses deflection routing. Deflected packets delivered to the wrong user are transparently rerouted to the switch. Each time a packet crosses the central switch, it collects amplifier noise and crosstalk due to imperfect optical switching. As the network load increases, the crosstalk level per crossing increases, as well as the number of crossings caused by deflections. The traffic statistics hence strongly affect the quality of the received signals. It is found that such networks work well only when lightly loaded. Using fast optical transmitters and receivers to deplete the optical layer has the positive effect of reducing both deflections and crosstalk, while allowing simpler architectures at the optical level.