Controlling high speed slotted data channels in WDM metro rings

The deployment of WDM technology in metropolitan area networks has moved the bottleneck from capacity to data processing at the network nodes. The data circulating in all wavelengths are converted from optical to electrical for processing, thus increasing considerably the system's cost and complexity. Abolishing the SONET paradigm, new data control mechanisms are designed for interconnected WDM metro rings, alleviating the required processing and pushing it to the network edges. Moreover, based on these control mechanisms, the transport of network data in the optical domain is feasible, reducing the system buffering needs as well as the total number of transceivers in the network nodes. The proposed scheme has been implemented in hardware for a prototype that supports a total of 1.2 Tbps metro traffic; its design is described.