JP4382068B2 - Optical transmission equipment - Google Patents

Description

  The present invention relates to an optical transmission device, and more particularly to an optical transmission device that transmits and receives wavelength division multiplexed optical signals to and from adjacent optical transmission devices. The present invention also relates to each optical transmission apparatus in an optical communication network system having a plurality of optical transmission apparatuses including a WDM transmission apparatus that transmits wavelength division multiplexed optical signals and a SONET / SDH transmission apparatus that transmits time division multiplexed optical signals. .

  In recent years, construction of a WDM ring in which optical signals of a plurality of SONET / SDH networks are multiplexed and transmitted using a wavelength division multiplexing (WDM) technique has been advanced.

  The WDM ring is provided with a WDM transmission apparatus (for example, OADM (Optical Add Drop Multiplexer)). This WDM transmission device adopts one or more SONET / SDH interface devices, assigns different wavelengths to the signals input (added) from the SONET / SDH transmission device, and performs wavelength multiplexing to provide multiple SONET / SDH interfaces. The SDH signal is transmitted through one optical fiber. In addition, the WDM transmission apparatus performs demultiplexing to extract each SONET / SDH signal and output (drop) it to the SONET / SDH transmission apparatus.

  In such a WDM ring, when a SONET / SDH interface device is newly adopted as a WDM transmission device, conventionally, a maintenance person (operator) has made necessary settings for each WDM transmission device.

  That is, the maintenance person first determines which WDM transmission device of which WDM ring the SONET / SDH interface device is to be expropriated (ADD / DROP), and assigns a line (wavelength) to the accommodated SONET / SDH interface device. It was. For this reason, the maintenance person reads the wavelength information from the operation system (hereinafter referred to as “OpS”), and checks the assignable wavelength. Next, the maintenance person reads the wavelength information from the OpS and checks the usage status for all WDM transmission apparatuses on the route for setting the line to check whether there is an unused wavelength that can be set. I was checking. In addition, when setting an optimal route taking into consideration the economics of the route (shortest route, etc.) and maintainability (redundant configuration, etc.), the maintainer determines the route by recognizing the entire network configuration. It was. Finally, the maintenance person sets the wavelength for the unused wavelength of each WDM transmission apparatus on the path.

  Each WDM transmission apparatus holds the wavelength information set by OpS in the database in the apparatus, but this wavelength information is lost when a failure occurs in the WDM transmission apparatus. Therefore, at the time of recovery from the failure, the maintenance person resets the wavelength information in the database of the WDM transmission apparatus.

  In addition, a plurality of optical signals having different wavelengths are wavelength-division multiplexed on one optical fiber between WDM transmission apparatuses. If a failure occurs at a certain wavelength used for transmitting an optical signal, 1 is used. The failure is avoided by switching one transmission line (optical fiber). Therefore, also in this case, it is necessary to set new wavelength information in the necessary WDM transmission apparatus.

  Thus, in the past, maintenance personnel had to perform various operations, so maintenance took time and the maintainability was not high.

  Also, a transmission path failure occurs between the WDM transmission device and the WDM transmission device on the network, between the WDM transmission device and the SONET / SDH transmission device, and between the SONET / SDH transmission device and the SONET / SDH transmission device. Conventionally, the transmission path is switched in a closed section between the transmission apparatuses to avoid a failure. Therefore, when there is no optical fiber to be switched between transmission devices or when all optical fibers to be switched have failed, the failure cannot be avoided.

  Furthermore, when changing the transmission route of a communication network system due to a failure or the like, as in the case of adding a line, the maintainer determines the route in the network and applies wavelength information to all WDM transmission devices on the route. Was read, the unused wavelength was confirmed, and the wavelength was set.

  Furthermore, even when a failure occurs in one of a plurality of wavelengths, the failure is avoided by switching one transmission line, so that other normal wavelength lines used are also momentarily interrupted. Had to be forced.

  An object of the present invention is to enable wavelength information to be automatically set in an optical transmission apparatus. Another object of the present invention is to enable all optical transmission apparatuses of an optical communication network system to automatically search for a route. Furthermore, an object of the present invention is to avoid a failure in a transmission line or a specific wavelength in the transmission line.

  An optical transmission apparatus according to a first aspect of the present invention is an optical transmission apparatus that transmits and receives wavelength division multiplexed optical signals to and from adjacent optical transmission apparatuses, and is wavelength division multiplexed from an optical transmission apparatus adjacent to the upstream side. Of the optical signals, an optical interface having a predetermined first wavelength is converted into a time-division multiplexed optical signal suitable for an adjacent SONET / SDH transmission device, and received from the SONET / SDH transmission device. An input interface unit for converting the input optical signal into an optical signal having a predetermined second wavelength included in a wavelength division multiplexed optical signal transmitted to an optical device adjacent to the downstream side, and an output interface unit A memory for storing first wavelength information including identification information and information representing the first wavelength, and second wavelength information including identification information of the input interface unit and information representing the second wavelength And the output interface A writing unit for writing the first and second wavelength information in a predetermined region of a time division multiplexed optical signal output from the face unit to the SONET / SDH transmission device, and a SONET / SDH transmission device to the input interface unit. A reading unit that reads the first and second wavelength information written in a predetermined region of the received time-division multiplexed optical signal and stores the information in the storage unit.

  According to the first aspect of the present invention, the first and second wavelength information is transmitted to the SONET / SDH transmission apparatus and returned from the SONET / SDH transmission apparatus. As a result, even if a failure occurs in the optical transmission device and the wavelength information is lost, the wavelength information can be received from the SONET / SDH transmission device at the time of recovery and automatically set to the recovered optical transmission device. .

  An optical transmission apparatus according to a second aspect of the present invention is an optical transmission apparatus that transmits and receives wavelength division multiplexed optical signals to and from adjacent optical transmission apparatuses, and is wavelength division multiplexed from an optical transmission apparatus adjacent to the upstream side. Of the optical signals, an optical interface having a predetermined first wavelength is converted into a time-division multiplexed optical signal suitable for an adjacent SONET / SDH transmission device, and received from the SONET / SDH transmission device. An input interface unit for converting the time-division multiplexed optical signal into an optical signal having a predetermined second wavelength included in the wavelength-division multiplexed optical signal transmitted to the optical transmission apparatus adjacent to the downstream side; First wavelength information including identification information of the output interface unit and information indicating the first wavelength; second wavelength information including identification information of the input interface unit and information indicating the second wavelength; A storage unit for storing A writing unit for writing the first and second wavelength information in a predetermined region of an optical signal of a predetermined third wavelength included in a wavelength division multiplexed signal transmitted to the optical transmission device adjacent to the downstream side; Reads the first and second wavelength information written in a predetermined region of an optical signal having a predetermined fourth wavelength among the wavelength division multiplexed optical signals from the optical transmission apparatus adjacent to the upstream side, and the storage unit And a reading unit for storing the data.

  According to the second aspect of the present invention, the first and second wavelength information is transmitted to the adjacent optical transmission device and transmitted from the adjacent optical transmission device. As a result, even if a failure occurs in the optical transmission equipment and the wavelength information is lost, each wavelength information can be received from the adjacent optical transmission equipment at the time of restoration and automatically set to the restored optical transmission equipment. .

  An optical transmission apparatus according to a third aspect of the present invention is an optical communication network having a plurality of optical transmission apparatuses including a WDM transmission apparatus that transmits wavelength division multiplexed optical signals and a SONET / SDH transmission apparatus that transmits time division multiplexed optical signals. Each optical transmission device in the system, the storage unit storing interface setting information indicating a connection relation between the optical transmission device adjacent to itself and the self, and transmission for transmitting the interface setting information to the adjacent optical transmission device A receiving unit that receives interface setting information of another optical transmission device transmitted from the adjacent optical transmission device and stores it in the storage unit, and the other optical transmission device received by the receiving unit. And a transfer unit that transfers the interface setting information to the adjacent optical transmission apparatus.

  According to the third aspect of the present invention, each optical transmission device has information indicating a connection relationship between all optical transmission devices of the optical communication network system. This makes it possible to automatically search for and set the optimum transmission path.

  In one embodiment, the optical transmission device further includes one or more interface units connected to adjacent optical transmission devices to perform input / output processing of the wavelength division multiplexed optical signal or time division multiplexed optical signal. The interface setting information is information indicating a connection relationship between the interface unit and an adjacent optical transmission device, or information indicating a connection relationship between the interface unit and another interface unit in the own optical transmission device. .

  An optical transmission apparatus according to a fourth aspect of the present invention is an optical communication network having a plurality of optical transmission apparatuses including a WDM transmission apparatus that transmits wavelength division multiplexed optical signals and a SONET / SDH transmission apparatus that transmits time division multiplexed optical signals. Each optical transmission device in the system, the storage unit storing interface setting information indicating a connection relationship between each optical transmission device of the optical communication network system and its adjacent optical transmission device, and stored in the storage unit The interface setting information, the identification information of the first optical transmission device to which the time division multiplexed optical signal is added to the optical communication network system, and the second in which the time division multiplexed optical signal is dropped from the optical communication network system A search unit that searches for a route from the optical transmission device to the second optical transmission device based on the identification information of the optical transmission device; A.

  According to the fourth aspect of the present invention, a path from its own optical transmission device to the second optical transmission device is searched based on the interface setting information. As a result, the optical signal transmission path is automatically searched for by each optical transmission apparatus without requiring setting by the maintenance person or the like to each optical transmission apparatus.

  According to an embodiment of the present invention, the optical transmission device is connected to an adjacent optical transmission device, and one or more interface units that perform input / output processing of the wavelength division multiplexed optical signal or time division multiplexed optical signal The interface setting information includes information indicating a connection relationship between the interface unit and an interface unit in an adjacent optical transmission device, or other interface units in the optical transmission device of its own. The identification information of the first optical transmission device is identification information of the interface unit to which the time division multiplexed optical signal is added, and the identification information of the second optical transmission device is the information Identification information of an interface unit to which a time division multiplexed optical signal is dropped, and the search unit receives the drop from the interface unit of its own optical transmission apparatus. Searching for a route to the interface unit to be.

  An optical transmission device according to a fifth aspect of the present invention is an optical transmission device that transmits and receives wavelength division multiplexed signals to and from adjacent optical transmission devices, and each wavelength signal transmitted and received by the wavelength division multiplexed signals. When a fault is detected by the wavelength fault detection unit, and when the fault is detected by the wavelength fault detection unit, the signal transmitted by the signal of the wavelength in which the fault is detected is transmitted and received by a signal of another unused wavelength. A switching unit for switching.

  As a result, even if a failure occurs at a specific wavelength, the failure can be recovered by switching only the wavelength without switching the entire transmission line, and signal loss at other wavelengths can be avoided. Can do.

In the following, embodiments of the present invention will be described with reference to automatic setting of wavelength information in a WDM transmission apparatus, and automatic search and automatic setting of optical signal paths in a communication network system having a WDM transmission apparatus.

<Automatic setting of wavelength information>
FIG. 1 is a block diagram showing a configuration of a WDM transmission apparatus 1 according to an embodiment of the present invention. The WDM transmission apparatus 1 is one of the transmission apparatuses that constitute a WDM ring. The WDM transmission apparatus 1 includes other WDM transmission apparatuses (that are upstream) (front stage) and downstream (rear stage) that constitute the WDM ring ( Are not connected).

  Further, as an example, the WDM transmission apparatus 1 is connected to two first and second SONET / SDH transmission apparatuses (not shown), and optical signals having a SONET / SDH frame format from these SONET / SDH transmission apparatuses. A signal is received (added), and an optical signal of the same frame format is transmitted (dropped) to these SONET / SDH transmission apparatuses.

  The WDM apparatus 1 includes reception side optical amplifiers (RAMP) 11a and 11b, transmission side optical amplifiers (TAMP) 12a and 12b, duplexers 13a and 13b, multiplexers 14a and 14b, OSC processing units 15a and 15b, switches ( SW) 16a to 16c, transmission transponders (RXP) 17a and 17b, reception transponders (TXP) 18a and 18b, a control unit 19, and a database (DB) 20.

  Note that RXP 17c and TXP 18c indicate a transmission transponder and a reception transponder newly added, as will be described later. In the WDM transmission apparatus 1, an optical switch may be provided between the duplexers 13a and 13b and the multiplexers 14a and 14b. The WDM transmission apparatus 1 may be provided with a spectrum analyzer (not shown).

  Optical signals of a plurality of wavelengths (hereinafter referred to as “WDM signals”) multiplexed by WDM are respectively input to the RAMPs 11a and 11b from adjacent WDM transmission apparatuses (not shown). Of these WDM signals, an optical signal having one wavelength is an OSC signal used for control, and an optical signal having another wavelength (hereinafter referred to as a “data signal”) is added from a SONET / SDH transmission apparatus. Or an optical signal dropped to the SONET / SDH transmission device. Each data signal has a SONET / SDH frame format, and has an overhead part (hereinafter referred to as “OH part”) that carries control data and the like, and a payload part that carries user data.

  The RAMPs 11a and 11b separate the OSC signal from the input WDM signal and apply it to the OSC processing units 15a and 15b, respectively, amplify the data signal, and output the amplified data signal to the demultiplexers 13a and 13b, respectively. .

  The demultiplexers 13a and 13b separate the input WDM signal into data signals for each wavelength, and provide the SW16a and 16b (and 16c) with the ones that are dropped into the SONET / SDH among the separated data signals. , And the others are supplied to the multiplexers 14a and 14b, respectively.

  In this embodiment, two (or three) data signals are added and dropped from the SONET / SDH transmission apparatus, but the number may be other than this.

  The optical signals given from the demultiplexers 13a and 13b and the TXPs 18a and 18b (and 18c) are input to the multiplexers 14a and 14b, respectively. The multiplexers 14a and 14b multiplex these optical signals having a plurality of wavelengths into WDM signals, and supply the WDM signals to the TAMPs 12a and 12b, respectively.

  The TAMPs 12a and 12b multiplex the OSC signals given from the OSC processing units 15a and 15b, respectively, to the WDM signals respectively input from the multiplexers 14a and 14b, and amplify the multiplexed WDM signals. The subsequent optical signal is output to an adjacent WDM transmission apparatus (not shown) via an optical fiber.

  SWs 16a and 16b (and 16c) select and output one of the optical signals input from the demultiplexers 13a and 13b, which is set by the control unit 19.

  The OSC processing units 15a and 15b process the OSC signals separated by the RAMPs 11a and 11b, respectively, and output the processed OSC signals to the TAMPs 12b and 12a, respectively. Further, the OSC processing units 15a and 15b read out wavelength information included in the OSC signal, give it to the control unit 19, and add the wavelength information given from the control unit 19 to the OSC signal. The wavelength information will be described later.

  RXPs 17a, 17b (and 17c) and TXPs 18a, 18b (and 18c) are SONET / SDH interface devices. RXP17a and TXP18a are connected to a first SONET / SDH transmission device (not shown) via an optical fiber, and RXP17b and TXP18b are connected to a second SONET / SDH transmission device (not shown) via an optical fiber. Has been.

  The RXPs 17a, 17b (and 17c) receive the single-wavelength data signal given from the SWs 16a, 16b (and 16c), convert the data signal into an electrical signal, and then specify it in the SONET / SDH transmission device on the receiving side. Converted into an optical signal having a predetermined wavelength and transmitted. When the data signal is converted into an electrical signal, the RXPs 17a, 17b (and 17c) write wavelength information (described later) of the WDM transmission apparatus 1 in a predetermined area of the OH unit.

  The TXPs 18a, 18b (and 18c) receive an optical signal (single wavelength) having a SONET / SDH frame format transmitted from the SONET / SDH transmission apparatus via an optical fiber, and temporarily convert the received optical signal into an electrical signal. After the conversion, it is converted into an optical signal (data signal) having a predetermined wavelength set by the control unit 19 and given to the multiplexers 14a and 14b. When the optical signal is converted into an electrical signal, the TXPs 18a, 18b (and 18c) respectively read the wavelength information (described later) of the WDM transmission apparatus 1 written in a predetermined area of the OH unit and give it to the control unit 19.

  The control unit 19 controls the RAMPs 11a and 11b, the TAMPs 12a and 12b, the SWs 16a to 16c, and the like, and performs processing to be described later on the wavelength information. The control unit 19 gives control signals to the OSC processing units 15a and 15b, SWs 16a to 16c, RXPs 17a and 17b (and 17c), TXPs 18a and 18b (and 18c), etc., and states and the like from these components. Signals that represent are received, but these signal lines have been omitted for the sake of clarity.

  The DB 20 stores wavelength information of its own WDM transmission apparatus 1 and wavelength information of WDM transmission apparatuses adjacent to the upstream side and the downstream side.

  Here, the “wavelength information” is information that associates the identification information of the TXP that receives the optical signal added from the SONET / SDH transmission apparatus to the WDM transmission apparatus and the wavelength of the WDM assigned to the optical signal, or This is information in which the identification information of the RXP that transmits the data signal dropped from the WDM transmission apparatus to the SONET / SDH transmission apparatus is associated with the WDM wavelength of this data signal. The identification information of TXP is information for uniquely identifying a certain TXP from other TXPs within one WDM transmission apparatus, and the identification information of RXP is the identification information of a certain RXP within another WDM transmission apparatus. This is information for uniquely identifying from RXP.

For example, the identification information of RXP17a the _{ID R1,} when the wavelength of the data signal input from SW16a to RXP17a and .lambda.i, wavelength information _{ID R1} and .lambda.i set _{{ID R1,} λi} are represented by. Further, if the identification information of TXP 18a is ID _T1, and the wavelength of the data signal output from TXP 18a is λj, the wavelength information is represented by {ID _T1 , λj}.

  Since the WDM transmission apparatus 1 is provided with two TXPs and two RXPs, the DB 20 has four sets of wavelength information.

  The four sets of wavelength information (own wavelength information) of the WDM transmission apparatus 1 are read from the DB 20 by the control unit 19 and given to the RXPs 17a and 17b. As described above, the RXPs 17a and 17b write this wavelength information in a predetermined area of the OH portion in the SONET / SDH frame format, and transmit it to the first and second SONET / SDH transmission apparatuses, respectively.

  An unused area is used as the predetermined area of the OH portion. If the wavelength information cannot be written at one time due to the large amount of information (number of bits) of wavelength information, the wavelength information is divided into OH portions of a plurality of frames. Will be sent.

  The own wavelength information transmitted from the RXPs 17a and 17b to the SONET / SDH transmission device is stored in a storage device inside the SONET / SDH transmission device. Then, the SONET / SDH transmission device reads out its own wavelength information stored in the internal storage device, writes it in the OH section, and transmits it to the WDM transmission device 1. The TXPs 18 a and 18 b read the own wavelength information included in the OH part of the received frame, and give the read own wavelength information to the control unit 19.

  The control unit 19 stores the own wavelength information given from the TXPs 18a and 18b in the DB 20, respectively. Note that the control unit 19 determines whether or not the own wavelength information given from the TXPs 18a and 18b is already stored in the DB 20, and stores the given own wavelength information in the DB 20 only when it is not stored. If it is already stored, it is not necessary to store it.

  As described above, the self-wavelength information is transmitted to the adjacent SONET / SDH transmission apparatus, stored in the SONET / SDH transmission apparatus, and returned from the SONET / SDH transmission apparatus. Even when a failure occurs in the DB 20 and the own wavelength information in the DB 20 is lost, when the WDM transmission apparatus 1 is started up after the failure recovery, the own wavelength information is transmitted from the adjacent SONET / SDH transmission apparatus. . As a result, the WDM transmission apparatus can automatically obtain its own wavelength information, and the own wavelength information is automatically stored in the DB 20. Therefore, it is not necessary for the maintenance person (operator) to newly set the own wavelength information in the DB 20, and the operation of the maintenance person is omitted.

  The control unit 19 also provides the own wavelength information to the OSC processing units 15a and 15b. The OSC processing units 15a and 15b write their own wavelength information in a predetermined area of the OSC signal and give it to the TAMPs 12b and 12a, respectively. As a result, the own wavelength information is transmitted to the adjacent WDM transmission apparatus.

  The adjacent WDM transmission apparatus stores its own wavelength information in its own DB and returns it to the WDM transmission apparatus 1 using an OSC signal. In this way, even if the WDM transmission apparatus 1 loses its own wavelength information due to a failure or the like, after the failure recovery, the WDM transmission apparatus 1 can automatically obtain its own wavelength information from the adjacent WDM transmission apparatus. This is particularly effective in the case of a WDM transmission apparatus that does not have an interface device (TXP, RXP) with a SONET / SDH transmission apparatus.

  Similarly, adjacent WDM transmission apparatuses transmit their own wavelength information (adjacent wavelength information) to the WDM transmission apparatus 1 using an OSC signal (predetermined area). The adjacent wavelength information is read out by the OSC processing units 15 a and 15 b and is given to the control unit 19. The control unit 19 stores adjacent wavelength information in the DB 20. The control unit 19 determines whether or not the same wavelength information as the wavelength information given from the OSC processing units 15a and 15b is already stored in the DB 20, and if it is already stored, the storage process is omitted. May be.

  The control unit 19 reads the adjacent wavelength information stored in the DB 20 and gives it to the OSC processing units 15a and 15b. The adjacent wavelength information received by the OSC processing unit 15a is given to the OSC processing unit 15a, and the adjacent wavelength information received by the OSC processing unit 15b is given to the OSC processing unit 15b.

  The OSC processing units 15a and 15b give the adjacent wavelength information given from the control unit 19 to the TAMPs 12b and 12a by OSC signals, respectively. As a result, the adjacent wavelength information is returned to each adjacent WDM transmission apparatus. As a result, even if a failure occurs in the adjacent WDM transmission apparatus, the adjacent WDM transmission apparatus can obtain the adjacent wavelength information from the WDM transmission apparatus 1 after the failure recovery, without requiring an operator's operation. Information can be set in its own DB. This is particularly effective when the adjacent WDM transmission apparatus does not have a SONET / SDH interface.

  When a new third SONET / SDH transmission device (not shown) is connected to the WDM transmission device 1, the WDM transmission device 1 includes RXP17c and TXP18c which are interface devices of the third SONET / SDH transmission device. It is attached. This attachment is performed, for example, by inserting card-type RXP 17c and TXP 18c into an empty slot of the WDM transmission apparatus 1 or the like.

  With this attachment, a detection signal is given to the control unit 19. When receiving the detection signal, the control unit 19 assigns the identification information and the unused (empty) wavelength in WDM (the wavelength of the data signal input to the SW 16c) to the newly installed RXP 17c and TXP 18c.

  The DB 20 stores already used wavelengths (used wavelengths) and unused wavelengths among the WDM wavelengths, and the control unit 19 stores any unused wavelengths (for example, unused wavelengths) from the DB 20. The shortest wavelength is selected and assigned. After the assignment, the control unit 19 changes the assigned wavelength from the unused wavelength to the used wavelength in the DB 20.

  As a result, the TXP 18c converts the SONET / SDH signal provided from the third SONET / SDH transmission device into a data signal having the assigned wavelength (λk), and supplies the data signal to the multiplexers 14a and 14b. Further, the RXP 17c converts the data signal having the wavelength λk given from the SW 16c into an optical signal having the wavelength of the SONET / SDH transmission device and transmits the optical signal to the third SONET / SDH transmission device.

  The control unit 19 generates two sets of wavelength information from the identification information of the RXP 17c and the TXP 18c and the assigned wavelength λk and stores them in the DB 20, and stores the generated two sets of wavelength information in the RXP 17c, the OSC processing unit 15a, 15b. As a result, the newly generated wavelength information is transmitted to and stored in the third SONET / SDH transmission apparatus and the adjacent WDM transmission apparatus in the same manner as already existing wavelength information, and is also returned to the return WDM transmission apparatus 1. The

  The OSC processing units 15a and 15b and the TXP 18c also extract this new wavelength information, give it to the control unit 19, and the control unit 19 stores it in the DB 20. As a result, the wavelength information of the newly installed SONET / SDH interface device can also be obtained from other SONET / SDH transmission devices or adjacent WDM transmission devices.

  In addition, at the time of provisioning by OpS, detection of a newly added SONET / SDH interface device, setting of a free wavelength, and the like may be performed. In addition, as a signal for transmitting wavelength information, a data signal having a wavelength other than the OSC signal can be used.

  Wavelength information of each WDM transmission device can be shared among all WDM transmission devices that constitute the WDM ring. In this case, the OSC processing unit of each WDM transmission apparatus adds the wavelength information of its own WDM transmission apparatus to the OSC signal, and from the OSC signal transmitted from the adjacent WDM transmission apparatus, the WDM transmission apparatus and other WDM transmission. Wavelength information of the transmission apparatus (that is, wavelength information of all WDM transmission apparatuses constituting the WDM ring) is extracted. Then, the control unit of each WDM transmission apparatus stores the extracted wavelength information of all the WDM transmission apparatuses in its own DB.

  Similarly, the wavelength information of all the WDM transmission apparatuses constituting the WDM ring can be transmitted to the SONET / SDH transmission apparatus, stored in the SONET / SDH transmission apparatus, and returned from the SONET / SDH transmission apparatus.

  When wavelength information of all WDM transmission apparatuses is shared in this way, in order to be able to distinguish which WDM transmission apparatus is wavelength information, the wavelength information includes identification information of the WDM transmission apparatus ( Node ID) is added. Then, a set of node ID and wavelength information is transmitted by the OSC signal and stored in the DB.

<Automatic route search and setting>
A process for automatically obtaining a route (including an optimum route) from one transmission device to another transmission device in a communication network system composed of a plurality of WDM transmission devices and SONET / SDH transmission devices will be described.

  In order to search for a route, each transmission device holds the preset information of its own interface device (hereinafter referred to as “IF device”), and all the other transmission devices have the interface setting information ( (Hereinafter referred to as “IF setting information”), usable wavelength information, route setting information, and failure information are notified (advertised). Each transmission device also holds the notified information.

  2A and 2B show pre-setting information for the IF device. This preset information is set in advance in the WDM transmission apparatus and the SONET / SDH transmission apparatus by a maintenance person or the like, and stored in, for example, DB 20 of the WDM transmission apparatus (in the SONET / SDH transmission apparatus, an internal storage device corresponding to DB 20). Is done. Further, as shown in FIG. 1 described above, when a new TXP or RXP is attached to the WDM transmission apparatus as the IF apparatus, the preset information of the new IF apparatus is also stored.

  The preset information is information indicating what IF device the WDM transmission device or the SONET / SDH transmission device has as an IF device for connection to an adjacent transmission device.

  FIG. 4 is an example of a network configuration diagram for explaining the preset information, and shows an IF device of a node connected in a ring and an IF device of a node not connected in a ring. In FIG. 4, WDM transmission apparatuses A, B, and C on two WDM rings R1, R2 and WDM ring R1, WDM transmission apparatus D on WDM ring R2, and SONET / SDH transmission apparatus E are shown.

  For example, the WDM transmission apparatus A has an IF apparatus 0 as an IF apparatus with an adjacent WDM transmission apparatus B. In the configuration diagram of the WDM transmission apparatus in FIG. 1, IF apparatus 0 includes, for example, duplexers 13a and 13b and multiplexers 14a and 14b. The WDM transmission apparatus A has an IF apparatus 1 as an IF apparatus (RXP and TXP) with the SONET / SDH transmission apparatus E, and an IF apparatus 2 as an SONET / SDH IF apparatus with the WDM ring R2. On the other hand, the SONET / SDH transmission apparatus E includes SONET / SDH IF apparatuses 1 and 2.

  As shown in FIG. 2A, the preset information includes the IF device of the ring-connected WDM transmission device and the IF device of the SONET / SDH transmission device that is not ring-connected as shown in FIG. 2B. Divided. Hereinafter, the WDM transmission apparatus and the SONET / SDH transmission apparatus may be collectively referred to as a node.

  The pre-setting information of the IF device of the node connected in the ring has an NE number, an IF number, a load setting value, a belonging ring number, an adjacent NE-IF number, and a default route. The pre-setting information of the IF device of the node that is not ring-connected has an NE number, an IF number, a load setting value, an assigned ring number, and an adjacent NE-IF number.

  The “NE number” is identification information of a node in which the IF device is provided, and is information for uniquely identifying the node in the communication network system. For example, in FIG. 4, reference signs A to E are NE numbers.

  The “IF number” is identification information of the IF device and is unique information within one node. In FIG. 4, symbols 0, 1, 2, etc. are IF numbers.

  In the following, in order to uniquely identify the IF device on the communication network system, a combination of NE number and IF number “NE-IF number” (for example, when NE number is A and IF number is 1) The IF number may be represented by reference A1). In addition, in the nodes connected in the ring, the reference numeral 0 is attached to the IF number of the IF device connected to the WDM ring. The IF numbers of other IF devices are given a code other than 0.

  The “load setting value” is a numerical value indicating an index of a band (transmission speed) of the IF device and a distance from an adjacent IF device, and includes a numerical value indicating the transmission speed and a distance between the IF devices.

  The “affiliation ring number” is identification information of the ring to which the node of the IF device belongs, and is set to 0 (0 is not used as ring identification information) when the node does not belong to the ring. . For example, in FIG. 4, the belonging ring number of nodes A to C is R1, and the belonging ring number of node E is R2. Since node E does not belong to the ring, its ring number is 0.

  The “neighboring NE-IF number” is identification information of the IF device of the adjacent node to which the IF device is connected, and consists of a set of the NE number of the adjacent node and the IF number of the adjacent node.

  The IF device that is ring-connected to the WDM ring has the NE-IF number of the IF device of the left adjacent node as the adjacent NE-IF number (L), and the NE-IF number of the IF device of the right adjacent node is adjacent. Each is set as the NE-IF number (R). For example, the adjacent NE-IF number (L) of the IF device A0 in FIG. 4 is C0, and the adjacent NE-IF number (R) is B0 (see FIG. 3A).

Also, in a WDM transmission apparatus (hereinafter also referred to as “boundary node”) connected to a SONET / SDH transmission apparatus, the SONET / SDH IF apparatus is connected to the adjacent NE-IF number (P _0). ) Is set. For example, for the IF device A0, the SONET / SDH IF devices 1 and 2 of the node A are set as adjacent NE-IF numbers (P ₀ ) (see FIG. 3B).

On the other hand, the adjacent NE-IF numbers (L) and (R) are not set in the SONET / SDH IF device in the WDM transmission device like the IF device A1, and the IF device E1 on the SONET / SDH transmission device side is not set. It is set as the adjacent NE-IF number (P ₀ ). Similarly, for the IF device A2, D2 is set as the NE-IF number (P ₀ ).

For the IF device of a node (SONET / SDH transmission device) that is not ring-connected like the node E, the NE-IF number outside the node is set as the adjacent NE-IF number (P ₁ ), and the NE-IF inside the node The number is set as the adjacent NE-IF number (P ₂ ). For example, the adjacent NE-IF number (P ₁ ) (external NE-IF number) of the IF device E1 in FIG. 4 is A1, and the adjacent NE-IF number (P ₂ ) (internal NE-IF number) is E2 ( (See FIG. 3C).

  “Default route” is used to prioritize transmission routes when there are a plurality of transmission routes with the same conditions when selecting a transmission route to be described later. Note that this default route is not provided in the preset information of the IF device of a node that is not ring-connected.

  5A and 5B show IF setting information transmitted (advertised) to all nodes on the communication network system by each node. This IF setting information is obtained by removing the load setting value from the preset information shown in FIGS. 2A and 2B.

  As described above, the IF setting information is transmitted between the WDM transmission apparatuses using an optical signal having a predetermined wavelength such as an OSC signal, and between the WDM transmission apparatus and the SONET / SDH transmission apparatus and between the SONET / SDH transmissions. This is performed between devices by storing data in a predetermined area of the OH portion of the SONET / SDH frame.

  Upon receipt of the IF setting information, each node stores the received IF setting information in its own internal storage device (for example, DB 20), and a node that has transmitted the IF setting information to itself (ie, a node located on the receiving side) The received IF setting information is transmitted (transferred) to other adjacent nodes. Thereby, the IF setting information of each node is transmitted (advertised) to all nodes, and each node stores the IF setting information of all nodes. As a result, each node has connection information indicating which IF device of which node is connected to which IF device of which node.

  FIG. 6 shows usable wavelength information. The ring-connected WDM transmission apparatus transmits an unused wavelength (left usable wavelength) WL among the wavelengths of the data signal transmitted to the WDM transmission apparatus adjacent to the left side and the WDM transmission apparatus adjacent to the right side. Among the wavelengths of the data signal, an unused wavelength (right usable wavelength) WR is transmitted.

  When there are a plurality of unused wavelengths, the plurality of wavelengths are transmitted by WL and WR. For example, when the unused wavelengths of the data signal transmitted to the WDM transmission apparatus adjacent to the left side are λi and λj, λi and λj are transmitted as the left usable wavelength WL.

  Similarly to the IF setting information, this usable wavelength information is also transmitted to all nodes and stored in each node. Note that the IF setting information and the usable wavelength information may be transmitted simultaneously or individually.

  FIG. 7 shows route setting information. The route setting information is information used to set the selected transmission route in each IF device of each node existing on the transmission route after the optimum transmission route is selected. This route setting information is also transmitted to all nodes by the OSC signal and the OH part, and is stored at each node.

  Here, the self NE-IF number, the destination NE-IF number, and the start point NE-IF number are a combination of the NE number and the IF number as described above. The own NE-IF number is the NE-IF number of the IF device that is the base point of the route search. The destination NE-IF number is the NE-IF number of the IF device to which the optical signal is dropped from the communication network system. The starting point NE-IF number is the NE-IF number of the IF device to which the optical signal is added to the communication network system from the outside.

  8A and 8B show failure information. The failure information is information transmitted when a failure has occurred in a specific wavelength of the transmission path or the WDM signal so that the node detecting the failure notifies other nodes of the occurrence of the failure. The node that detects a failure is a node (in particular, a node located on the downstream side of the optical signal) to which the transmission line or wavelength in which the failure has occurred is connected.

  The failure information includes data “failure occurrence” indicating failure occurrence, NE-IF numbers of two IF devices located at both ends of the transmission path or wavelength where the failure occurred, and when a failure occurs only at a specific wavelength. It includes an “injury occurrence wavelength” that represents the wavelength at which the failure occurred. This failure information is notified to all nodes by the OSC signal or the OH part when a failure is detected.

  Next, a method for searching for a route from a start-point IF device to which an optical signal is externally added to the communication network system to a destination IF device to which the optical signal is dropped to the outside, and selecting an optimum route among the searched routes Will be described.

  FIG. 9 to FIG. 11 are flowcharts showing the flow of processing for route search and route selection from the source IF device to the destination IF device. FIG. 10 shows the detailed processing flow of the topology creation processing (S2) of FIG. 9, and FIG. 11 shows the detailed processing flow of the optimum transmission path selection processing (S3) of FIG.

  FIG. 12 shows a configuration example of a communication network system in which a plurality of WDM rings are connected by a SONET / SDH transmission apparatus. A specific example of the optimum transmission path selection process will be described using this configuration example.

  The communication network system of FIG. 12 has WDM rings R1, R2, and R3. The WDM ring R1 includes WDM transmission apparatuses A to C. The WDM ring R2 includes WDM transmission apparatuses D to F. The WDM ring R3 includes WDM transmission apparatuses G to I.

  The WDM rings R1 and R2 are connected by a SONET / SDH interface between the IF devices B1 and D1. The WDM rings R1 and R3 are connected by a SONET / SDH interface between the IF devices C1 and H1 and a SONET / SDH interface between the IF devices C2 and H2. Assume that the distance between IF devices C2 and H2 is greater than the distance between IF devices C1 and H1. The WDM rings R2 and R3 are connected by a SONET / SDH interface between the IF devices F1 and G1.

  The numbers in parentheses in the WDM rings R1, R2, and R3 represent the number of unused wavelengths between WDM transmission apparatuses. Assume that there are the same number of unused wavelengths on both the left and right sides. For example, there are three unused wavelengths between nodes A and C.

  Here, the search for the route of the optical signal added to the IF device A1 of the node (WDM transmission device) A and dropped from the IF device I2 of the node I and the selection of the optimum route will be described.

  The maintenance person or the like registers the pre-setting information of the IF device A1 added to the node A through OpS. Note that OpS may be provided in a specific node (including node A) in FIG. 12, or may be provided as a device different from the node.

  When the pre-setting information of the IF device A1 is registered (stored) in the node A, the IF setting information of the IF device A1 is transmitted to and stored in all nodes by an OSC signal or the like.

  Subsequently, the start point NE-IF number A1 and the destination NE-IF number I2 are set in the node A via OpS. The node A (for example, the control unit 19 in FIG. 1) obtains from the preset information that the IF device to which the IF device A1 is connected is the IF device A0, and sets the route with the IF device A0 as its own NE-IF number. Information (see FIG. 7) is created (S1 in FIG. 9). The destination NE-IF number of this route setting information is I2, and the start point NE-IF number is A1.

  Subsequently, the node A creates topology information, which is configuration information necessary for searching for a route and selecting an optimum route, based on the route setting information and IF setting information (S2). FIG. 13 shows an example of topology information.

  First, the node A sets its own NE-IF number, start point NE-IF number, and destination NE-IF number of the route setting information in the topology information (S21 in FIG. 10). Here, A0 is set as its own NE-IF number, A1 is set as the start NE-IF number, and I2 is set as the destination NE-IF number in the topology information.

  Subsequently, the node A obtains the ring number to which the destination IF apparatus belongs based on the destination NE-IF number and the IF setting information, and sets the obtained ring number in the topology information (S22). Since the destination IF device I2 is included in the node I and the node I belongs to the ring R3, the ring number to which the destination IF device belongs is R3.

  Next, based on the IF setting information, the node A selects a boundary IF device that can be connected from the belonging ring R1 of the node A (the own IF device A0 or the starting IF device A1) to the belonging ring R3 of the destination IF device I2. The extracted NE-IF number of the boundary IF device is set in the topology information (S23).

  Here, the boundary IF device is an IF device having 0 as the NE-IF number at the boundary node of the belonging ring R1. In the network configuration example of FIG. 12, since IF devices B0 and C0 have transmission paths that can be connected to ring R3, IF devices B0 and C0 are extracted as boundary IF devices, and these numbers B0 and C0 are set in the topology information. The

  Next, the node A determines whether the transmission rate of the SONET / SDH interface connecting the rings R1 and R3 can withstand the transmission rate of the optical signal added to the start point IF device A1, using the load setting value (band information). Confirm based on. If there is a section that cannot be used because the transmission rate of the SONET / SDH interface is smaller than the transmission speed of the optical signal to be added, the node A sets it as an unusable section in the topology information (S24). The transmission speed of the optical signal to be added is preset in the node A by a maintenance person or the like.

  For example, in FIG. 12, the transmission speed of the optical signal to be added is 600 Mbps, whereas the transmission from the IF device C2 (SONET / SDH interface) to the IF device H2 (referred to as “first route”) is performed. The transmission speed of the path from the IF apparatus C1 to H1 (referred to as “second path”) is 50 Mbps, and the path from the IF apparatus B1 to G1 via D1 and F1 (referred to as “third path”). The third route becomes a transmittable route when the transmission speed of 2.4 Gbps is. Therefore, only a route that can be transmitted is selected, and the other first route and second route are set in the topology information as unusable sections.

  Here, it is assumed that there is no difference in all the transmission rates from the first route to the third route, and all the routes have a transmission rate capable of transmitting the added optical signal.

  Next, the node A extracts all routes from the boundary IF device to the destination ring based on the IF setting information and the topology information (S25). In FIG. 12, the third route is extracted from the first route.

  Subsequently, when there are a plurality of extracted routes, the node A sets the priority (priority order) of the route. This priority is set so that a high priority is given to a route with a small number of connections of the SONET / SDH interface device in order to improve the transmission efficiency of the optical signal. Therefore, the node A obtains the number of connections of the SONET / SDH interface based on the IF setting information, and sets the ring connection priority (priority order) in the topology information based on the number of connections (S26).

  In the network configuration example of FIG. 12, all paths from the boundary IF devices B0 and C0 that can be connected to the ring R3 to the ring R3 are first obtained from the IF setting information. At that time, by extracting the number of times that the ring number of the ring that has passed through is extracted, this number of changes can be obtained as the number of connections of the SONET / SDH interface of each transmission path.

  For example, in the first route, the ring number changes once from ring R1 to R3, so the number of SONET / SDH interface connections is one. Similarly, the number of connections of the SONET / SDH interface on the second path is 1, and the number of connections of the SONET / SDH interface on the third path is 2.

  When the transmission path passes through a plurality of nodes (SONET / SDH transmission apparatuses) K and L that do not belong to the ring as in the network configuration example shown in FIG. It is counted as the number of SONET / SDH interface connections. Therefore, the number of connections is 3 in FIG.

  Even if the number of SONET / SDH interface connections on the two routes is the same or the number of SONET / SDH interface connections on one transmission route is less than that on the other, the length of one route is When it is longer than the other, or when the amount of traffic on one route is greater than that of the other (that is, the unused bandwidth of one route is less than the other), the short route or unused bandwidth It is preferable to select a route with a large amount.

  For this reason, the number of SONET / SDH interface connections can be determined using the load setting value obtained from the IF setting information of the IF device on the start side to which the extracted path is connected.

  For example, in FIG. 12, the number of connections of the SONET / SDH interface of the first route and the second route is both 1 and the same, but the first route is much longer than the second route. It is assumed that the load setting value related to the distance between the IF devices is set to 10 among the load setting values, and the load setting value related to the distance of the IF device C1 is set to 1. In this case, the number of connections of the SONET / SDH interface of the first path is set to 1 × 10 = 10, and the number of connections of the SONET / SDH interface of the second path is set to 1 × 1 = 1. As a result, the priority of the second route is set higher than that of the first route.

  In this way, the node A obtains the priority of the third route from the first route connecting the rings, and sets the obtained priority to the “ring connection priority” of the topology information. In the topology information of FIG. 13, priorities are set in the order of the second route, the third route, and the first route.

  Thus, the topology information creation process (S2 in FIG. 9) is completed.

  Next, the node A executes search processing for all routes and selection processing for the optimum route from the source IF device to the destination IF device based on the IF setting information and topology information (S3 in FIG. 9).

  First, the node A selects a route selection method (S31). In this embodiment, there are two route selection methods, methods α and β. The method α is a method (shortest distance selection method) for selecting a route that minimizes the number of IF devices that pass from the own IF device to the destination IF device. The method β is a method (traffic congestion avoidance selection method) that selects a route while avoiding a route with a small number of unused wavelengths in the transmission path that passes from the own IF device to the destination IF device. Which method to use is preset in the node A by OpS.

  When the method α is selected (“α” in S31 of FIG. 11), the node A first selects a route with high priority based on the topology information (S32). In FIG. 12, the second route [C0-C1-H1-H0] has the highest priority among the three routes from the first route to the third route as shown in the topology information of FIG. (The code in the brackets is the NE-IF number, and the route is represented in this way by the sequence of NE-IF numbers).

  The second path passes through the IF device C0 in the ring R1. Therefore, the node A searches for a route from the own IF device A0 to C0 based on the IF setting information, and searches for two routes in the clockwise direction and the counterclockwise direction in the ring R1. The clockwise route is [A0-B0-C0], and the counterclockwise route is [A0-C0].

  Similarly, the second path passes through the IF device H0 in the ring R3. Therefore, OpS searches for a route from IF device H0 to destination IF device I2 (or its boundary IF device I0) in ring R3 based on the IF setting information, and in ring R3, there are two clockwise and counterclockwise directions. Search for a route. The clockwise route is [H0-G0-I0 (-I2)], and the counterclockwise route is [H0-I0 (-I2)].

  As a result, four routes [A0-C0-C1-H1-H0-I0-I2] and [A0-C0-C1-H1] are routed from the own IF device to the destination IF device via the second route. -H0-G0-I0-I2], [A0-B0-C0-C1-H1-H0-I0-I2], [A0-B0-C0-C1-H1-H0-G0-I0-I2] are searched. The Of these four paths, the higher priority is given in order from the smallest number of IF devices that pass through.

  FIG. 15 shows transmission route information of all routes searched by applying the method α to the communication network system shown in FIG. Here, four routes having priority levels 1, 2, 2, and 3 are routes that pass through the second route. The reason why there are two routes having priority 2 is that the number of IF devices through which both routes pass is the same.

  Similarly, for the third route having the second priority in the topology information, the route from the own IF device A0 to the destination IF device I2 is searched via the third route, and the priority is assigned to the searched route. Is attached. The priority given to the route passing through the third route is assigned a priority after 4 after the priorities 1 to 3 attached to the route passing through the second route. That is, the searched route is a route with priorities 4 to 7 shown in FIG.

  Similarly, a route is searched for the second route having the third priority in the topology information, and priorities 8 to 10 are assigned to the searched route.

  The node A stores all the routes searched in this way in a storage device (for example, the DB 20 in FIG. 1) as transmission route information shown in FIG. Then, the node A uses the route with the highest priority (route having the priority 1 in FIG. 15) [A0-C0-C1-H1-H0-I0-I2] as the optimum route among all the searched routes. select.

  In FIG. 15, the numerical value in the parenthesis represents the minimum number of unused wavelengths of each ring passing through. For example, (3-2) of the route with priority 2 passes through the rings R1 and R3, and therefore indicates the minimum number of unused wavelengths 3 of the ring R1 and the number of minimum unused wavelengths 2 of the ring R3. . Also, the paths marked with the symbols * 1 and * 2 have the same priority because the number of IF devices that pass through is eight. Similarly, routes marked * 3 to * 5 have the same priority, and paths marked * 6 to * 8 and paths marked * 9 to * 10 also have the same priority. .

  When there are multiple transmission paths having the same priority in this way, the more detailed priority can be set by applying the other method β (described later) to the transmission paths having the same priority. (S34).

  In addition, even if the method β is applied, if a route with the same priority exists (“Yes” in S35), the priority is set using the default route of the preset information (see FIGS. 2A and 2B). (S36). Thereby, the transmission path information of FIG. 15 is updated to the transmission path information of FIG.

  When the method β is selected in step S31 (“β” in S31), as in the case of the method α, first, the route with the highest priority is selected in accordance with the topology information, and the own IF that has passed through the selected route is selected. A route from the device to the destination IF device is searched. A priority is assigned to the searched route, and transmission route information is created. FIG. 17 shows transmission route information of all routes searched by applying the method β to the communication network system shown in FIG.

  As the routes passing through the second route having the highest priority in the topology information, the same four routes as in the case where the method α described above is applied are searched.

  Among these, regarding the clockwise route and the counterclockwise route in the ring R1, the clockwise route has an unused wavelength number of 8, whereas the counterclockwise route has an unused wavelength number of 3 ( (See FIG. 12). Therefore, a higher priority is assigned to the clockwise route than to the counterclockwise route.

  The route passing through the clockwise route in the ring R1 is further classified into two routes in the clockwise direction and the counterclockwise direction in the ring R3. In the ring R3, since the number of unused wavelengths is 2 in both the clockwise direction and the counterclockwise direction, the same priority is given to the paths in both directions.

  Accordingly, the same priority 1 is assigned to both the clockwise route in the ring R1 and the clockwise route in the ring R3, and the clockwise route in the ring R1 and the counterclockwise route in the ring R3. (See FIG. 17).

  Similarly, the counterclockwise path in the ring R1 is further classified into two paths in the clockwise direction and the counterclockwise direction in the ring R3. The two classified paths have the same number of unused wavelengths. Therefore, the same priority 2 is applied to the counterclockwise direction in the ring R1 and the clockwise path in the ring R3, and the counterclockwise direction in the ring R3 and the counterclockwise path in the ring R3. Assigned (see FIG. 17).

  In the same way, a route passing through the third route is searched, and among the searched routes, the following higher priority is assigned in order from the route with the largest number of unused wavelengths. Subsequently, a route passing through the first route is searched, and a priority is assigned in the same manner. Then, transmission path information shown in FIG. 17 is created.

  In FIG. 17, routes marked with * 11 and * 12 indicate routes having the same priority. Reference numerals * 13 to * 14, * 15 to * 16, * 17 to * 18, * 19 to * 20, * 21 to * 22, * 23 to * 24, * 25 to * 26 have the same priority. The route is shown.

  When there are a plurality of transmission paths having the same conditions as described above (“Yes” in S39), the other method α is applied to the paths having the same priority (S39), so that a difference in priority is obtained. Can be provided. In addition, when there is a route having the same priority even after the method α is applied (“Yes” in S35), the default route of the preset information (see FIGS. 2A and 2B) is used to change the priority. Can be provided (S36).

  As described above, the transmission path information in FIG. 17 is updated to the transmission path information in FIG. Then, the node A can select the route [A0-B0-C0-C1-H1-H0-I0-I2] with the highest priority as the optimum route.

  When the node A selects the optimum route based on the transmission route information, the node A transmits route setting information to an adjacent IF device on the optimum route (S4 in FIG. 9). For example, in the optimum route by the method α, route setting information is transmitted to the IF device C0 of the node C. As described above, A0 is set in the own NE-IF number, I2 is set in the destination NE-IF number, and A1 is set in the starting NE-IF number in the route setting information.

  When node C receives the route setting information from node A, node C changes its own NE-IF number to C0. Then, the node C executes the processing shown in FIGS. 9 to 11 based on the route setting information after the change, and creates topology information, creation of transmission route information, selection of the optimum route, and the like.

  Here, when creating transmission path information, the node C may select a counterclockwise path from the IF apparatus C0 to the IF apparatus B0 via the IF apparatus A0 in the ring R1. However, since the node C has received the route setting information in which the NE-IF number is set to A0 from the node A, the node C excludes the route via the IF device A0 and creates the transmission route information. It has become. As a result, processing efficiency can be improved.

  When the node C selects the optimum route, the node C transmits route setting information to an IF device (for example, the IF device C1) adjacent to the optimum route, and repeats the same processing. Such processing is executed by each node on the optimum route to the node I to which the destination IF device I2 belongs.

  In this way, when adding a line, each node can select an optimum route for transmitting the newly added optical signal to the drop destination. Each node searches for a currently usable wavelength using the usable wavelength (see FIG. 6) of the selected optimum path, and assigns one of the retrieved usable wavelengths to this optical signal. it can. As a result, it is possible to automatically set a route for a new optical signal without requiring an operator's operation.

  FIG. 19 is a block diagram showing another configuration example of the communication network system, and is an explanatory diagram of the occurrence of a transmission path failure. FIG. 20 shows transmission path information when a failure occurs in the transmission path.

  In the communication network system of FIG. 19, the optical signal added to the IF device A1 is transmitted through the optimum path [A1-A0-B0-B1-E1-E0-G0-G1] and dropped from the IF device G1. Shall.

  In this state, when a failure occurs in the transmission path (optical fiber) between the IF device B1 and the IF device E1, the currently used route [A1-A0-B0-B1- including the failure section B1-E1]. E1-E0-G0-G1] becomes unusable.

  The WDM transmission apparatuses B and E at both ends of the occurrence section detect the failure and transmit the failure information to other nodes in the communication network system. As described above, the failure information has the structure shown in FIG. 8A, and includes “failure occurrence” data indicating the occurrence of the failure, and B1 and E1 as NE-IF numbers at both ends of the failure occurrence location.

  By transmitting this failure occurrence information, all the nodes know that a transmission path failure has occurred between IF devices B1 and E1, and the nodes are unusable.

  When each node receives the failure information, each node excludes the route including the failure section [B1-E1] as unusable in the transmission route information shown in FIG. 20, and selects another route. Since the route with the highest priority among the usable routes after the occurrence of the failure is [A1-A0-C0-C1-D1-D2-F1-F0-G0-G1], each node is connected to this route. Is selected as the optimum route, and the wavelength used between the WDM transmission apparatuses is automatically selected according to the optimum route.

  As a result, it is possible to select a transmission path having the highest priority among the paths that do not pass between the nodes H and I from the transmission path information, and to automatically select the wavelength to be used by using the usable wavelength of the passing interface. .

  In this way, when a transmission path failure occurs, the transmission path can be automatically switched to avoid the failure.

  For example, when a wavelength failure occurs between the WDM transmission apparatuses A and B at a wavelength (wavelength λ1) used for data signal transmission, both WDM transmission apparatuses A and B An unused wavelength (wavelength λ3) is automatically retrieved, and the retrieved unused wavelength λ3 can be assigned to the wavelength of the data signal transmitted by the wavelength λ1.

  That is, when a failure occurs in the wavelength λ1 between the WDM transmission apparatuses A and B, the receiving WDM transmission apparatus B detects the failure in the wavelength λ1. Then, the WDM transmission apparatus B searches for and selects a usable unused wavelength λ3. The WDM transmission apparatus B adds information indicating that the wavelength λ1 cannot be used to the wavelength information and failure information of the OSC signal and transmits the information.

  The WDM transmission apparatus A receives the OSC signal from the WDM transmission apparatus B and knows that the wavelength λ1 has failed and cannot be used. Then, the WDM transmission apparatus A searches for an unused wavelength (λ3) and selects an unused wavelength λ3.

  Thus, the data signal transmitted / received at the wavelength λ1 is transmitted / received at the wavelength λ3 after the failure occurs.

  A route relocation command is provided to reset the route based on the latest transmission route information, and by inputting the route relocation command to each node from OpS (or a maintenance person, etc.), the transmission route is updated with the latest transmission route information. Can be automatically switched using.

  By using this path rearrangement command, it is possible to control the timing of switching the currently used transmission path to the optimum transmission path based on the latest transmission path information. For example, when the transmission path is changed due to the addition of a line, the path is not switched until a predetermined timing is reached in order to avoid a momentary signal interruption, and a path relocation command is sent from OpS to each node at a predetermined timing. The transmission path can be changed at a predetermined timing.

  Note that when a failure occurs, it is necessary to quickly switch the transmission path to the optimum transmission path. Therefore, it is preferable that the rearrangement of the optimum transmission path is performed even if the path rearrangement command is not input. Therefore, when a failure occurs, even if no command is input, the node detects the failure and executes route relocation.

  In addition, when a failure in a transmission path or a selected wavelength is restored by maintenance, it is preferable that the transmission path is switched at a predetermined timing by inputting a certain path rearrangement command in order to avoid a momentary interruption as in the case of expansion. .

The present invention can be used for optical transmission apparatuses, in particular, WDM transmission apparatuses and SONET / SDH transmission apparatuses using WDM technology, and communication network systems having these optical transmission apparatuses.

  According to the present invention, first, even if the wavelength information of the database of the WDM transmission apparatus is lost due to a failure of the WDM transmission apparatus or the like, it is not necessary to restore the database by the OpS or the maintenance person, and the adjacent nodes Wavelength information can be input from and set. As a result, maintainability is improved and the operation of the maintenance person can be omitted.

  Secondly, according to the present invention, when a new line is added to a communication network system including a WDM transmission apparatus, an optimum route can be automatically selected. This makes it possible to design a transmission path for a line quickly and effectively.

  In addition, as a selection method for selecting the optimum route, either a method for minimizing the number of WDM transmission devices that pass through or a method for selecting a section with a large number of unused wavelengths between WDM transmission devices can be selected. Since the route priority can be set in consideration of the distance between the SDH transmission devices, the maintainability of the network can be improved.

  According to the present invention, thirdly, it is not necessary to switch one entire transmission line due to a failure of one wavelength, and by setting the wavelength information of the wavelength where the failure has occurred to a normal unused wavelength, It is possible not to affect the line disconnection. This also improves maintainability.

  Fourth, when a transmission path failure occurs, the transmission path is switched in a closed section between adjacent nodes, and there is no switching target between nodes, or even if all switching targets are faulty By performing the search, another route can be selected and a signal can be transmitted. This avoids transmission line failures and improves maintainability.

FIG. 1 is a block diagram showing a configuration of a WDM transmission apparatus according to an embodiment of the present invention. 2A and 2B show the preset information of the interface device. 3A to 3C show examples of interface information. FIG. 4 is an example of a network configuration diagram for explaining the interface information. 5A and 5B show interface setting information transmitted to all nodes on the communication network system by each node. FIG. 6 shows usable wavelength information. FIG. 7 shows route setting information. 8A and 8B show failure information. FIG. 9 is a flowchart showing the flow of processing for route search and route selection from the source interface device to the destination interface device. FIG. 10 is a flowchart showing the flow of processing for route search and route selection from the source interface device to the destination interface device. FIG. 11 is a flowchart showing the flow of processing for route search and route selection from the source interface device to the destination interface device. FIG. 12 shows a configuration example of a communication network system in which a plurality of WDM rings are connected by a SONET / SDH transmission apparatus. FIG. 13 shows an example of topology information. FIG. 14 shows a configuration example of a communication network system. FIG. 15 shows transmission route information of all routes searched by applying the method α to the communication network system shown in FIG. FIG. 16 shows transmission route information of all routes searched in the communication network system shown in FIG. FIG. 17 shows transmission route information of all routes searched by applying the method β to the communication network system shown in FIG. FIG. 18 shows transmission route information of all routes searched in the communication network system shown in FIG. FIG. 19 is a block diagram showing another configuration example of the communication network system, and is an explanatory diagram of the occurrence of a transmission path failure. FIG. 20 shows transmission path information when a failure occurs in the transmission path.

Claims (12)

Each optical transmission device in an optical communication network system having a plurality of optical transmission devices including a WDM transmission device for transmitting wavelength division multiplexed optical signals and a SONET / SDH transmission device for transmitting time division multiplexed optical signals,
A storage unit for storing interface setting information indicating a connection relationship between each optical transmission device of the optical communication network system and its adjacent optical transmission device;
The interface setting information stored in the storage unit, identification information of a first optical transmission device to which a time division multiplexed optical signal is added to the optical communication network system, and the time division multiplexed optical signal are included in the optical communication network A search unit that searches for a route from its own optical transmission device to the second optical transmission device based on identification information of the second optical transmission device dropped from the system;
Have
The interface setting information stored in the storage unit includes its own interface setting information indicating a connection relationship between itself and an optical transmission device adjacent to the self, and another optical transmission device received from the optical transmission device adjacent to the self Interface setting information
Furthermore, the optical transmission apparatus characterized in that the own interface setting information and the interface setting information received from the other optical transmission apparatus are transferred to an adjacent optical transmission apparatus. In claim 1 ,
One or more interface units connected to adjacent optical transmission devices to perform input / output processing of the wavelength division multiplexed optical signal or time division multiplexed optical signal;
The interface setting information indicates information indicating a connection relationship between the interface unit and an interface unit in an adjacent optical transmission device, or indicates a connection relationship between the interface unit and another interface unit in the own optical transmission device. Information,
The identification information of the first optical transmission device is identification information of an interface unit to which the time division multiplexed optical signal is added, and the identification information of the second optical transmission device is dropped of the time division multiplexed optical signal. Identification information of the interface part,
The search unit searches for a route from the interface unit of the own optical transmission device to the dropped interface unit;
Optical transmission device. In claim 2 ,
The optical transmission apparatus, wherein the search unit creates route information representing the searched route, and the storage unit stores the route information. In any one of Claim 2 or 3 ,
The interface setting information is transmitted as an optical signal having a predetermined wavelength between the WDM optical transmission apparatuses, and between the WDM optical transmission apparatus and the SONET / SDH transmission apparatus and between the SONET / SDH transmission apparatuses, the SONET / SDH frame. Sent by the overhead part,
Optical transmission device. In any one of Claims 2 to 4 ,
The search unit searches the SONET / SDH transmission path when a plurality of the paths are searched and at least two or more of the paths pass through a SONET / SDH transmission path connecting WDM rings. Prioritize the SONET / SDH transmission path based on the number of SONET / SDH transmission equipment or the distance of the SONET / SDH transmission path.
Optical transmission device. In any one of Claims 2 to 5 ,
The search unit assigns a higher priority in order from the smallest number of interface units via each route when a plurality of the routes are searched.
Optical transmission device. In claim 6 ,
The search unit assigns a higher priority in order from the smallest number of interface units through which each route passes. As a result, when there are a plurality of routes having the same priority, the search unit selects the route having the same priority. Thus, in order from the section with the largest number of unused wavelengths between the WDM optical transmission devices of the WDM ring, the higher priority is given.
Optical transmission device. In any one of Claims 2 to 5 ,
The search unit assigns a higher priority in order from a section having a larger number of unused wavelengths between WDM optical transmission apparatuses in a WDM ring when a plurality of the paths are searched.
Optical transmission device. In claim 8 ,
The search unit assigns the same priority when there are a plurality of routes having the same priority as a result of assigning a higher priority in order from the section with the largest number of unused wavelengths between the WDM optical transmission apparatuses of the WDM ring. The higher priority is given to the routes that have the highest priority in order from the smallest number of interface units via each route.
Optical transmission device. In claim 7 or 9 ,
The search unit discriminates the priorities of the routes having the same priority based on a preset default route when there are a plurality of routes having the same priority as a result of assigning the priorities. ,
Optical transmission device. In any one of Claims 2 to 10 ,
The route setting information including the identification information of the interface unit of the optical transmission apparatus, the identification information of the added interface unit, and the identification information of the dropped interface unit is adjacent to the route searched by the search unit. A transmission unit for transmitting to the optical transmission device,
The search unit of the adjacent optical transmission device searches for a route not passing through the interface unit having identification information of the interface unit of the own optical transmission device included in the route setting information;
Optical transmission device. In any one of Claims 2 to 11 ,
A transmission path fault detection unit for detecting a fault in the transmission path between the own optical transmission apparatus and the adjacent optical transmission apparatus;
When a failure is detected by the transmission line failure detection unit, a transmission unit for transmitting transmission line failure occurrence information having identification information of interface units connected to both ends of the transmission line;
A receiver for receiving transmission path failure occurrence information from another optical transmission device;
And
The search unit excludes, from the path information, a path that passes through the transmission path in which the failure has occurred, based on the transmission path failure occurrence information;
Optical transmission device.

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