Abstract: A multi-grained network includes edge modules that switch high-variance multi-rate data traffic, and independent core modules that switch paths having different granularities. The core may include core modules that switch fixed-size data blocks, core modules that switch channels or bands of channels, core modules that switch entire links, and core modules that cross-connect channels or links. To simplify the control functions, the core modules operate independently from each other. Direct link, band or channel connections may be established for selected ingress-egress edge module pairs, if traffic volumes warrant. The use of graded granularity in the core simplifies the control function and reduces network cost.

Abstract: An optical core node that includes optical switching planes interfaces, at input, with multi-channel input links and, at output, with multi-channel output links. The number of channels per link can differ significantly among the links, necessitating that the input (output) links have different connection patterns to the switching planes. Such an optical core node requires new methods of assigning an incoming wavelength channel to one of the optical switching planes. The assignment of the channels of input and output links to input and output ports is established in a manner that increases input-output connectivity and, hence, throughput. Additionally, the networks that may be formed with such optical core nodes require new routing methods. A preferred method of selecting a path through the core node favors switching planes connecting to a small number of links. In a time-division-multiplexing (TDM) mode, the method of path selection is complemented by temporal packing of TDM frames.