Abstract: An apparatus stores information identifying unallocated channels for each of spans, where a span indicates a section between adjacent nodes of a plurality of nodes in a communication network. The apparatus extracts unallocated channels for each of all spans provided between a start point node and an end point node of a path in the communication network, by referring to the information, and determines a channel including consecutive unallocated spans which are arranged on routes including the path and spans outside the path, and whose number is minimum among the extracted unallocated channels, as a channel to be set to the path.

Abstract: A transmission device that is coupled to a mesh network includes a memory, and a processor coupled to the memory, configured to detect an another transmission device in the mesh network, which receives a first data signal that is same as a second data signal requested to the transmission device, and branch the first data signal to the transmission device from the detected another transmission device.

Abstract: An apparatus stores information identifying unallocated channels for each of spans, where a span indicates a section between adjacent nodes of a plurality of nodes in a communication network. The apparatus extracts unallocated channels for each of all spans provided between a start point node and an end point node of a path in the communication network, by referring to the information, and determines a channel including consecutive unallocated spans which are arranged on routes including the path and spans outside the path, and whose number is minimum among the extracted unallocated channels, as a channel to be set to the path.

Abstract: A noise suppression method is used in an optical transmission system which includes node equipments transmitting a WDM optical signal. First node equipment drops a first optical signal from the WDM optical signal. The method includes: transmitting a failure signal that specifies the first optical signal from second node equipment to the first node equipment via a first route when the second node equipment arranged on the first route for transmitting the first optical signal to the first node equipment has detected a failure of the first optical signal; transmitting a shutoff signal that specifies the first optical signal from the first node equipment toward the second node equipment via the first route; and shutting off an optical output of a wavelength corresponding to the first optical signal in third node equipment that has relayed the failure signal and has received the shutoff signal.

Abstract: A failure protection method of a network connecting between nodes by multiple working paths and a protection path is disclosed. An allocation bandwidth is determined to allocate to a detected path where a failure is detected in multiple paths being set to the multiple working paths, depending on the detected path. The detected path is switched from one of the multiple working paths to the protection path. Data to be transmitted by the detected path is transmitted by using the allocation bandwidth determined within an entire bandwidth of the protection path.

Abstract: A transmission device that is coupled to a mesh network includes a memory, and a processor coupled to the memory, configured to detect an another transmission device in the mesh network, which receives a first data signal that is same as a second data signal requested to the transmission device, and branch the first data signal to the transmission device from the detected another transmission device.

Abstract: A failure protection method of a network connecting between nodes by multiple working paths and a protection path is disclosed. An allocation bandwidth is determined to allocate to a detected path where a failure is detected in multiple paths being set to the multiple working paths, depending on the detected path. The detected path is switched from one of the multiple working paths to the protection path. Data to be transmitted by the detected path is transmitted by using the allocation bandwidth determined within an entire bandwidth of the protection path.

Abstract: A noise suppression method is used in an optical transmission system which includes node equipments transmitting a WDM optical signal. First node equipment drops a first optical signal from the WDM optical signal. The method includes: transmitting a failure signal that specifies the first optical signal from second node equipment to the first node equipment via a first route when the second node equipment arranged on the first route for transmitting the first optical signal to the first node equipment has detected a failure of the first optical signal; transmitting a shutoff signal that specifies the first optical signal from the first node equipment toward the second node equipment via the first route; and shutting off an optical output of a wavelength corresponding to the first optical signal in third node equipment that has relayed the failure signal and has received the shutoff signal.