Patent ID: 8964581
Filing Date: 2015-02-24
Classification: H04B,H04J,H04L

Abstract:
1. A bandwidth variable communication method in an optical path network, in which communication apparatuses are connected by optical transmission, that includes a network management apparatus having a function for setting and managing an optical path, the method being performed by the network management apparatus, or by the network management apparatus and the communication apparatus when the network management apparatus sets or changes an optical path that passes through plural communication apparatuses, the method comprising: an optical signal quality deterioration amount obtaining step of obtaining an optical signal quality deterioration amount in a route of the optical path; a modulation format selection step of selecting a modulation format in which a spectrum bandwidth is the narrowest from among modulation formats by which transmission is available on conditions of the optical signal quality deterioration amount and a desired bit rate B (bit/s); a control message exchange step of exchanging control information for controlling a transmission unit, a receiving unit and a route exchange unit in the communication apparatus based on a selection result in the modulation format selection step, the control information being exchanged between the network management apparatus and a control unit of each communication apparatus on the optical path route; an optical signal transmission step of generating and transmitting the optical signal of the selected modulation format and of the bit rate B (bit/s) based on the control information received by the control unit in the control message exchange step, the optical signal transmission step being performed by the transmission unit of a communication apparatus of a start point of the optical path; a route exchange step of switching an output port of the optical path by the route exchange unit of the communication apparatuses in a section through which the optical path passes; a bandwidth change step of changing a passband of the route exchange unit based on the control information; and an optical path receiving step of receiving the optical path of the selected modulation format and of the bit rate B (bit/s) in the receiving unit of the communication apparatus in an end point of the optical path.