The conservative mode and the greedy mode scheduling algorithms for OBS switch with shared buffer are presented and discussed. Their performance is evaluated by computer simulations, as well as that of the greedy mode with void-filling algorithm. Simulation results show that the conservative mode and the greedy mode have different characteristics under different input load. The greedy mode and the conservative mode are more applicable in a real system than that with void-filling, owing to their lower computational complexity and FIFO characteristic. Finally, a composite algorithm integrated by the conservative mode and the greedy mode is proposed, which is adapted to the input load with the help of an input load monitor. The simulation results reveal that it has favorable performance under different load.

A two stage Combline Bandpass Filter (C-BPF) of the Vertically Installed Planar (VIP) structure has been investigated, which is essentially composed of a strongly coupled microstrip lines terminated with a planar fin and through-hole combined with the tapping feed approach. The principle and performance of this filter is studied approximately by an equivalent circuit model and also by the normalized 3D-FDTD method more exactly. The time domain iteration in the FDTD analysis is performed in an expanded time dimension resulting in a reduced CPU time. Some of the obtained numerical results are compared well with the measured ones. A modified VIP combline BPF has the advantages of simple structure, easy tuning, low cost, versatile bandwidth control and good skirt characteristics brought about by two attenuation poles.