Scheduling transmissions in WDM broadcast-and-select networks

Considers a broadcast-and-select, wavelength division multiplexed (WDM), optical communication network that is packet switched and time slotted. The amount of time it takes transmitters and receivers to tune from one wavelength to another is assumed to be T slots. The authors consider all-to-all transmission schedules, which are defined to be ones that schedule a packet transmission between each input-output pair. They present upper and lower bounds for the minimum length of such schedules. In particular, if each of N inputs has a tunable transmitter and each of N outputs has a tunable receiver then the minimum length is between (N+o(N))(√T+1) and ((N+o(N))√T. This provides some insight into the relationship between packet delay and T. The authors also consider schedules that do not allow packet transmissions while a transmitter or receiver is tuning from one wavelength to another