Telecommunications switches are presented, including expandable optical switches that allow for a switch of N inputsM outputs to be expanded arbitrarily to a new number of N inputs and/or a new number of M outputs. Switches having internal switch blocks controlling signal bypass lines are also provided, with these switches being useful for the expandable switches.

This invention is related to two-stage optical packet switch fabrics for TE (terabit Ethernet)-based HPCNs (high performance computing networks). The main features of the invented optical switch architecture are the following: (1) it can support thousands of TE links; (2) it has a low signal power loss and requires no optical amplifiers; (3) it can switch WDM packets simultaneously without using wavelength converters.

The patent application presents various embodiments of the two-stage switch architecture. In one embodiment, the first stage comprises K NN (N inputs and N outputs) AWGs and the second stage comprises N KK OSSes (optical space switches). This results in a port count of KN. Each input can transmit N wavelengths and a total of KN.sup.2 packets can pass through the switch fabric simultaneously without blocking. The switch fabric is named AS for the technologies used in the two stages. Currently 3232 AWGs are available. This allows an AS switch fabric to support more than a couple of thousands TE links easily.

In another embodiment, the first stage comprises N KK OSSes and the second stage comprises K NN AWGs. It is named SA for the same reason given above. Similar to the first embodiment, the total number of source and destination ports supported by an SA switch fabric equals KN, and KN.sup.2 packets can be transmitted simultaneously through the switch fabric. All the features and advantages of the AS architecture are inherited by the SA architecture.

In still another embodiment, two AS or SA switch fabrics are used in parallel to construct a switching system capable of handling any kind of unbalanced traffic loads. A port processor for keeping a bounded delay, for processing and re-sequencing packets in such a switching system is also presented in this patent application.

A repeater device that can achieve signal transferring and path switching in optical transmission lines susceptible to environmental changes is provided. The repeater device receives weak signal light and normal reference light and transmits them in a communication network. The repeater includes: an optical route selector that selects an input-side spatial link connected to an upstream adjacent node and an output-side spatial link connected to a downstream adjacent node; a link state detector that detects a link state of at least one of the input-side spatial link and the output-side spatial link, wherein the link state is an attenuation rate or a transmission rate; and a controller that controls the optical route selector to select an optimal pair of output-side spatial link and input-side spatial link according to the link state.