A FLEXIBLE WDM RING NETWORK

An optical WDM network for use for instance in a larger e.g. meshed network is the hubbed type and comprises parallel fiber ring paths (1b), a hub (3h) and satellite nodes (3A, 3B, 3C) connected in the ring path. Client equipments are connected to the hub and the satellite nodes. A client equipment connected to the main node can communicate with a client equipment connected to any of the satellite nodes, using a number of wavelength channels equal to the number of client equipments in the satellite nodes. The wavelength channel used for transmission from the hub can e.g. be fixed or selected by a tunable optical transmitter (31). The WDM transmitters (9) in the satellite nodes transmits light signals in a fixed one of the wavelength channels to the fiber ring path. A single band drop filter (35) is arranged in the main node to receive the light signals from the satellite nodes. The band drop filter has a drop range selected to drop selected ones of the wavelength channels used by the WDM transmitters in the satellite nodes. This allows the use of light signals of wavelength channels outside the drop range of the band drop filter for carrying information in the network. In the network flexible connections are achieved in without using cross-connect elements.