Optimal Scheduling Algorithms in WDM Optical Passive Star Networks

All-to-all broadcast scheduling problems are considered in WDM optical passive star networks where k wavelengths are available in the network. It is assumed that each node has exactly one tunable transmitter and one xed tuned receiver. All transmitters can tune to k di erent wavelengths, and have the same tuning delay to tune from one wavelength to another. In this paper, we take to be a nonnegative integer which can be expressed in units of packet durations. When all-to-all broadcasts are scheduled periodically in the network, the lower bounds are established on the minimum cycle length depending on whether each node sends packets to itself or not. And then, we present optimal scheduling algorithms in both cases for arbitrary number of wavelengths and for arbitrary value of the tuning delay. 1