Patent ID: 7590349
Filing Date: 2009-09-15
Classification: H04J,H04Q

Abstract:
1. A node device, in an optical communication network, which comprises a plurality of node devices including a start point node device, a relay node device and an end point node device, optical fibers connecting adjacent node devices for transmitting wavelength multiplexed signals, and a management device connected to each of said plurality of node devices for generating reserve packets, and in which an optical path is set from said start point node device to said end point node device via said relay node device, wherein when said node device is referred to as a self node device, said self node device comprises an input section, an optical path switching section, an output section and a control section; wherein said input section demultiplexes input wavelength multiplexed signals which are input from an adjacent node device, which is adjacent to said self node device, into each wavelength so as to generate a plurality of single wavelength signals, and sends each of said single wavelength signals to said optical path switching section; wherein responding to an optical path switching signal received from said control section, said optical path switching section switches an optical path to a destination node device, which is said adjacent node device, for each of said single wavelength signals, and sends each of signal wavelength signals to said output section; wherein said output section multiplexes each of said single wavelength signals which have been sent from said optical path switching section to a common destination node device so as to generate an output wavelength multiplexed signal, and sends said output wavelength multiplexed signal to said common destination node device; and wherein said control section comprises: a storage section for recording a cost matrix which indicates a transmission cost between said self node device and each adjacent node device, and for recording a link state table which indicates an optical fiber between said self node device and each adjacent node device, whether transmission is being performed or not in said optical fiber, and a wavelength being used for transmission; packet receive means for receiving a reserve packet including information on said start point node device, said end point node device, transmission wavelength, and said transit node device, or a reserve failure packet, from an adjacent node device, to be stored in said storage section; destination node setting means for referring to the information of said cost matrix and said stored reserve packet, when judging said start point node device, said transit node device, and a transmission source node device of said reserve failure packet, out of said adjacent node devices, as transmission impossible node devices and judging the rest as transmission possible node devices, then storing a transmission possible node device of which said transmission cost is lowest in said storage section as a tentative destination node device; transmission possibility judgment means for referring to said link state table on an optical fiber connected to said tentative destination node device, judging the same as transmission possible if the transmission wavelength of said reserve packet is not in use, and as transmission impossible if the transmission wavelength of said reserve packet is in use, and updating said tentative destination node device stored in said storage section to a transmission impossible node device; reserve packet update means for adding information on said self node device to the information on a transit node device of said reserve packet stored in said storage section so as to update said reserve packet in response to said judgment as transmission possible; reserve failure packet generation means for generating a new reserve failure packet which is different from said reserve failure packet if said transmission possible node device does not exist in the judgment by said destination node setting means; packet transmission means for reading said updated reserve packet from said storage section and sending the same to said tentative destination node device if said updated reserve packet exists, or sending a new reserve failure packet to said reserve packet transmission source if said new reserve failure packet is generated; and switching signal generation means for generating said optical path switching signal in response to reception of an optical path setting signal generated by said management device and sending said optical path switching signal to said optical path switching section.