Contention resolution of synchronous fixed length optical packet with two stage shared fiber delay line optical packet switch

In optical packet switching network, packets may arrive at the switching node in an unorganized manner. Therefore, contention occurs and it is not a trivial task to resolve contention due to lack of optical RAM technology. Packet contention resolution is a major issue in optical packet switching (OPS). This paper focuses on contention resolution using fiber delay lines (FDLs) which are used to buffer contended packets in order to forward these packets to the desired output port to some future time slots. This paper proposes a two stage shared fiber delay line optical packet switch to resolve contention. FDLs are implemented in two stages using extremely simple auxiliary switch. The packet loss performance of the proposed switch is investigated with respect to average delay. Simulation result shows that, the packet loss rate of the proposed architecture under heavy traffic load of 0.9 is between ~10^-3 and ~10^-4 for a 32 × 32 switch using 64 FDLs, and zero packet loss rate achievable when traffic load is less than 0.8.