Abstract: An optical transceiver is configured to use, as an electric signal, a digital modulation signal having a predetermined bit rate. The optical transceiver includes a case having a space for storing a component therein and a resistor being arranged between upper and lower surfaces of the space and having conductance of from 1 S/m to 1,000 S/m. The space has a height equal to or less than a wavelength in a free space of an electromagnetic wave of a frequency corresponding to the predetermined bit rate. At least a part of the height of the space is larger than a half of the wavelength. The height of the space is smaller than a width of the space. The width of the space is smaller than a depth of the space.

Abstract: An optical module is attachable to and detachable from a cage. The optical module includes a module case, a slider attached to the outside of the module case for releasing coming-off prevention from the cage, and a leakage reducing layer intervening between the module case and the slider to reduce leakage of an electromagnetic wave.

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 optical add-drop multiplexer having first and second routes includes: an optical cross connect; a first multiplexer optically coupled to a plurality of output ports of the optical cross connect; a second multiplexer optically coupled to a plurality of other output ports of the optical cross connect; a first wavelength selective switch to generate a first WDM optical signal including an optical signal output from the first multiplexer and to guide the first WDM optical signal to the first route; and a second wavelength selective switch to generate a second WDM optical signal including optical signal output from the second multiplexer and to guide the second WDM optical signal to the second route.

Abstract: An optical transceiver is configured to use, as an electric signal, a digital modulation signal having a predetermined bit rate. The optical transceiver includes a case having a space for storing a component therein and a resistor being arranged between upper and lower surfaces of the space and having conductance of from 1 S/m to 1,000 S/m. The space has a height equal to or less than a wavelength in a free space of an electromagnetic wave of a frequency corresponding to the predetermined bit rate. At least a part of the height of the space is larger than a half of the wavelength. The height of the space is smaller than a width of the space. The width of the space is smaller than a depth of the space.

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: There is provided an optical transmission device, the optical transmission device including a wavelength selective switch configured to select a first optical signal having a first wavelength from an input signal of wavelength division multiplexing, an optical filter circuit configured to include an optical tunable filter having a pass wavelength that is tunable to a second wavelength of a second optical signal for passing therethrough, a splitter configured to split the input signal, a split signal split by the splitter being transferred to the optical filter circuit, and a coupler configured to couple the first optical signal selected by the wavelength selective switch and the second optical signal passed through the optical filter circuit.

Abstract: A node device in an optical transport ring network including plural node devices connected in a ring form using plural optical transmission paths so that optical transport frames of a working line and a protection line are transmitted using the plural optical transmission paths, includes a control information transmitter, when a failure occurs in the optical transmission paths, transmitting the optical transport frame to an opposing node device as a transmission destination node in the optical transmission paths, the optical transport frame including switching control information; and a switcher receiving the optical transport frame including switching control information, the optical transport frame being transmitted to the node device as the transmission destination node, forming a loop back to fold a transmission path between the plural optical transmission paths, and switching the optical transmission path from the work line to the protection line.

Abstract: A communication apparatus operable to set a path based on path setting information used to set a communication path over a communication network formed by a plurality of the communication apparatuses, the communication apparatus including a first storage medium operable to store first path setting information formatted with a first format, a second storage medium operable to store second path setting information formatted with a second format, and a controller operable to control to convert control information of the communication apparatus in which the first path setting information stored in the first storage medium is set, to the second path setting information formatted with the second format.

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.

Abstract: There is provided a communication device including a score information storage unit to store score information indicating a score as an evaluated value of a communication path; a receiver unit to receive a route connection notice including current score information; a routing unit to acquire the score information stored in the score information storage unit, and select the communication path next to the communication path based on the acquired score information of the communication path; a score updating unit to add a score of the communication path selected by the routing unit to the current score of the partial communication route indicated by the current score information, and update the current score information to the added score as a new current score; and a transmission unit to transmit the route connection notice including the current score information.

Abstract: A node device in an optical transport ring network including plural node devices connected in a ring form using plural optical transmission paths so that optical transport frames of a working line and a protection line are transmitted using the plural optical transmission paths, includes a control information transmitter, when a failure occurs in the optical transmission paths, transmitting the optical transport frame to an opposing node device as a transmission destination node in the optical transmission paths, the optical transport frame including switching control information; and a switcher receiving the optical transport frame including switching control information, the optical transport frame being transmitted to the node device as the transmission destination node, forming a loop back to fold a transmission path between the plural optical transmission paths, and switching the optical transmission path from the work line to the protection line.

Abstract: There is provided an optical transmission device, the optical transmission device including a wavelength selective switch configured to select a first optical signal having a first wavelength from an input signal of wavelength division multiplexing, an optical filter circuit configured to include an optical tunable filter having a pass wavelength that is tunable to a second wavelength of a second optical signal for passing therethrough, a splitter configured to split the input signal, a split signal split by the splitter being transferred to the optical filter circuit, and a coupler configured to couple the first optical signal selected by the wavelength selective switch and the second optical signal passed through the optical filter circuit.

Abstract: An optical add-drop multiplexer having first and second routes includes: an optical cross connect; a first multiplexer optically coupled to a plurality of output ports of the optical cross connect; a second multiplexer optically coupled to a plurality of other output ports of the optical cross connect; a first wavelength selective switch to generate a first WDM optical signal including an optical signal output from the first multiplexer and to guide the first WDM optical signal to the first route; and a second wavelength selective switch to generate a second WDM optical signal including optical signal output from the second multiplexer and to guide the second WDM optical signal to the second route.

Abstract: A flexible open ring optical network includes a plurality of nodes connected by twin or other suitable optical rings. Each node is operable to passively add and passively drop traffic from the rings. The nodes may include a transport element for each ring. The transport elements include an optical splitter element and an optical combiner element. The optical splitter element is operable to passively combine an add signal including local add traffic and a first transport signal including ingress traffic from a coupled optical ring to generate a second transport signal including egress traffic for transmission on the coupled optical ring. The optical combiner element is coupled to the optical splitter element and is operable to passively split a third transport signal including the ingress traffic to generate a drop signal including local drop traffic and a fourth transport signal including the ingress traffic.

Abstract: In order to increase the efficiency of large-capacity transmission, the continuity of divided signals generated by dividing a multiplexed signal is maintained and the original large-capacity multiplexed signal is restored. A signal dividing section divides a multiplexed signal to generate a plurality of divided signals in the STS or STM transmission interface format. A guarantee information adding section adds guarantee information for guaranteeing the continuity of the divided signals to each of the divided signals to generate transmission signals. A signal sending section sends the transmission signals via a transmission line in the transmission interface format. A signal receiving section receives the transmission signals. A signal restoring section restores the multiplexed signal by constructing the divided signals on the basis of the guarantee information.

Abstract: A flexible open ring optical network includes a plurality of nodes connected by twin or other suitable optical rings. Each node is operable to passively add and passively drop traffic from the rings. The nodes may include a transport element for each ring. The transport elements include an optical splitter element and an optical combiner element. The optical splitter element is operable to passively combine an add signal including local add traffic and a first transport signal including ingress traffic from a coupled optical ring to generate a second transport signal including egress traffic for transmission on the coupled optical ring. The optical combiner element is coupled to the optical splitter element and is operable to passively split a third transport signal including the ingress traffic to generate a drop signal including local drop traffic and a fourth transport signal including the ingress traffic.