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))(/spl radic/T+1) and ((N+o(N))/spl radic/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.>

The go-back- infinity protocol is studied under a two-state Markov chain packet-loss model, where the delay for packet acknowledgements is random. Expressions are presented for the z transform, mean, and variance of the time tau taken to successfully transmit N packets. In addition, the authors discuss how the probability distribution of the delay for packet acknowledgements can affect E mod tau mod .>

The authors consider linear lightwave networks with a single waveband that have N inputs, each with a transmitter, and N outputs, each with a receiver, interconnected by optical links, broadcast stars, and wavelength-independent 2*2 switches. The transmitters and receivers can tune to C different wavelengths. The authors describe a rearrangeably nonblocking network that is a modification of the Benes network and uses transmitters that are fixed tuned and switches with two states. The network uses (1+o(1))N/log/sub 2/(N/C) switches, which is shown to be nearly the minimum number. It is also shown that, if C=o(log N), then a rearrangeably nonblocking network requires (1+o(1))Nlog/sub 2/N switches even if the switches have more than two states.>

A study is made of the effect of correlated packet losses for some simple automatic repeat request (ARQ) protocols: go-back- infinity , and Blast. The packet losses are modeled by a two state Markov chain and it is assumed that the round trip delay is random. Expressions are derived for the z-transform and the first and second moments of the time ( tau ), taken to successfully transmit N packets for go-back- infinity and variations of the Blast protocol. For go-back- infinity , bounds are derived for E( tau ), and it is shown that for a fixed mean round trip delay, E( tau ) is minimized when the distribution of the round trip delay is such that its variance is minimized. Some of the protocols investigated show a significant improvement in performance when packet losses occur in bursts. The authors propose and analyze a variation of the Blast protocol which seems particularly suited to bursty packet loss situations.>