Optical transmission networks including transmission networks like WDM (Wavelength Division Multiplexing), SDH (Synchronous Digital Hierarchy) and SONET (Synchronous optical network) have been widely used in telecommunication field. In optical transmission network, optical cross connection is commonly needed, that is, any optical fiber signal is connected and reconnected with other optical fiber signals controllably in optical network nodes. For example, optical channel signals are reconnected automatically by digital cross-connection device with auto line distributing function.
In the digital cross-connection device, the cross-connection board is a single board in core status, which is mainly divided into space-division cross boards (space-division modules) and time-division cross boards (time-division modules). Recently, with the development of user service, the capacity of a single time-division module cannot meet the need of high-capacity time-division service of user due to factors like cost, and the application of multi-time-division modules comes into being, however, as the multi-time-division module cannot achieve the real full cross, using the traditional service configuration method when services are switched and adjusted in the time-division module will lead to instant service interruption time exceeding 50 ms greatly (automatic protection switching time requirement, requiring that the service of whole network needs to be recovered to be normal in 50 ms when the transmission path is faulted), thereby results in an interrupt of user service.