Communications network architecture

摘要

A communications network (2) including a number of optical fibre loops (8) having respective access nodes (10), an optical wavelength group for traffic within the loop, and at least one other optical wavelength group for traffic to the another loop. The network (2) has an optical cross-connect (4) for routing traffic between the loops by selecting the wavelength groups. The optical cross-connect (4) is passive, and the network (2) may be a metropolitan area network with traffic being carried by WDM signals.