JP5117592B2 - Optical network device and optical network system - Google Patents

Description

  The present invention relates to an optical network device that constitutes an optical network by switching optical signals, and in particular, an optical network device that relays optical signals without converting them into electrical signals, and optical communication established by the switching operation thereof. The present invention relates to an optical network system that compensates the quality of an optical signal for a road.

  Devices such as optical fibers, optical amplifiers, optical demultiplexers, optical multiplexers, optical switches, etc., used for communication using optical communication paths, have unique optical propagation characteristics and are transmitted light. Affects signal quality. As a technique for automatically compensating for such propagation characteristics, for example, Patent Documents 1 and 2 disclose a method of feedback controlling a dispersion compensator based on a signal monitoring result at a receiving end.

JP 2005-64905 A JP 2002-208992 A

  Optical fibers, optical amplifiers, optical demultiplexers, optical multiplexers, optical switches, and other devices that make up optical communication paths exhibit optical propagation characteristics that depend on the optical wavelength, and are nonlinear with respect to optical power. Show good behavior. As an optical signal passes through these optical devices, the signal gradually deteriorates, resulting in a transmission error in communication data.

  Optical propagation characteristics are expressed by indices such as S / N ratio, dispersion of optical propagation group delay, polarization dispersion, dispersion mode delay, optical power, Q factor, etc. Necessary for the correct transmission of data.

  For this purpose, it is necessary to compensate for degraded optical signals. For this purpose, dispersion compensators, optical amplifiers, optical 2R (Reshaping and Re-amplification) type or optical 3R (2R and Retiming) type optical signals are used. A regenerator or the like is used.

  Conventional optical transmission systems that only connect the start and end points are intended for point-to-point data transmission, and the transmission destination and transmission path cannot be changed. In order to transfer data to a desired destination or change the route, it is necessary to separately combine a device that electrically switches the transfer route. As an apparatus for switching the route, an IP (Internet Protocol) router, an MPLS (Multi-Protocol Label Switching) switch, an ATM (Asynchronous Transfer Mode) switch, a TDM-DXC (Time-Division Multiplexing Digital Cross Connect) apparatus, or the like is used.

  In such a communication network, the end point of the optical transmission path and its path are fixed, so that setting of the compensator was relatively easy. However, in the method of switching the route by electrical means, the apparatus becomes complicated and expensive as the communication speed increases. Therefore, OXC (Optical Cross Connect) is used to configure a single optical transmission line with a plurality of wavelengths, thereby individually configuring communication paths for each wavelength, and then switching the path in units of light wavelengths. ), PXC (Photonic Cross Connect), OADM (Optical Add-Drop Multiplexer), etc. are being developed.

  In order to configure an optical network using an optical network device, every time an optical signal is relayed in the optical network, the signal is first converted into an electrical signal and then regenerated, and an optical-electrical-optical (OEO) conversion is performed. And a method of reproducing an optical signal as it is without converting it into an electric signal. An optical network that does not perform optical-electrical-optical conversion is called an all-optical network. When performing optical-electrical-optical conversion, the end point of the optical transmission section and its path are fixed, whereas in an all-optical network that does not perform optical-electrical-optical conversion, the end point of the optical transmission section and its end point The route and route length change.

  Further, GMPLS (Generalized MPLS), ASON (Automatic Switched Optical Network), and the like have been adopted as control technologies for setting a route in an optical network. In a network using these, the path through which an optical signal passes without being converted to an electrical signal and its distance can be dynamically adjusted by optimizing traffic or recovering from a path failure, even during communication establishment. Change.

  As described above, when the path through which an optical signal passes without being converted into an electrical signal and the distance thereof dynamically change, it becomes a problem to compensate the light propagation characteristics for each changed communication path. Furthermore, in an optical network that uses a plurality of wavelengths and a WDM (Wavelength Division Multiplex) that configures an optical path for each wavelength in a relay section, a plurality of optical communication paths that pass through the same optical fiber or optical device are mutually connected. Compensation considering the deviation is required.

  For example, when optical power is compensated by an optical amplifier, if the level deviation between a plurality of wavelengths incident on the same optical amplifier becomes large, the S / N ratio (signal-to-noise ratio) deteriorates for a low level wavelength. However, distortion occurs with respect to wavelengths having a large level, resulting in transmission errors in the communication data. Further, when distortion occurs in an optical fiber or an optical amplifier, an unnecessary spectrum is generated due to a non-linear effect accompanying the distortion, and a transmission error may occur due to the influence. Patent document 1 and patent document 2 do not mention such a problem and its solution.

  In an optical network employing WDM, an optical network device connected to each other via an optical fiber is generally an interface unit connected to the optical fiber, a switch unit for switching a communication path, and a control unit for controlling the operation of the switch unit. It is comprised including. Further, the interface unit includes an optical device such as an optical amplifier, a duplexer, and a multiplexer.

  When compensation is performed using such an optical network, it is possible to avoid the incidence of a plurality of wavelengths with deviations on the same optical device by separating the wavelengths once and performing compensation using a compensator for each wavelength. However, in general, the compensator is expensive, and if all the optical network devices arranged in the communication path perform compensation for each wavelength, the cost of the entire network increases.

  An object of the present invention is to provide an optical network device and an optical network using the optical network device that make it possible to select a location where optical signal characteristics are compensated in an optical network.

  In order to achieve the above object, an optical network device of the present invention includes an interface unit connected to an optical fiber, and a switch unit that sets a communication path by switching connection to an input / output optical signal of the interface unit. And control the operation of the switch unit using an optical signal measuring device for measuring the characteristics of the optical signal and a communication path establishment control protocol for exchanging a control message for establishing the communication path with another optical network device. The measurement value obtained by the optical signal measuring device is exchanged with another optical network device by the communication path establishment control protocol. The measurement values are exchanged with the optical network device, so that the compensation is set by looking at the entire optical path established in the optical network, rather than the individual optical network devices individually compensating. This makes it possible to select a location for compensation in the optical network. Therefore, the number of optical signal regenerators affecting the cost can be determined appropriately, and the cost of the optical network can be reduced.

  According to the present invention, in an optical network composed of a plurality of optical network devices, an optical signal regenerator for compensating optical signal characteristics is not provided in all optical network apparatuses, but optical signal characteristics are compensated. An optical network device can be selected.

1 is a configuration diagram for explaining an embodiment of an optical network device and a network using the same according to the present invention. FIG. The block diagram for demonstrating the optical network apparatus of this embodiment. The block diagram for demonstrating another optical network apparatus of this embodiment. The block diagram for demonstrating the edge interface part used for the optical network apparatus of this embodiment. The block diagram for demonstrating the core interface part used for the optical network apparatus of this embodiment. The block diagram for demonstrating the control part used for the optical network apparatus of this embodiment. The block diagram for demonstrating the example of the optical wavelength path | pass established in the optical network of this embodiment. The figure for demonstrating the compensation control sequence in the optical network of this embodiment. The figure for demonstrating the software structure of the control part used for the optical network apparatus of this embodiment. The figure for demonstrating the connection relation of an optical signal regenerator, an optical measurement part, and an interface. The figure for demonstrating the structure of an interface structure table. The figure for demonstrating the structure of an optical amplifier specification table. The figure for demonstrating the structure of an optical measurement part specification and a monitoring condition table. The flowchart for demonstrating a compensation amount determination process.

  Hereinafter, an optical network device according to the present invention and an optical network using the same will be described in more detail with reference to embodiments shown in the drawings. In addition, in each figure used for description of this embodiment, the same code | symbol shall be attached | subjected to the same thing or a similar thing.

  In this embodiment, as a communication path establishment control signal, GMPLS (Generalized Multi-Protocol Label Switching) extended RSVP-TE (Resource Reservation Protocol) which is a protocol IETF RFC3473 created by IETF (Internet Engineering Task Force) which is an international organization of the Internet. -Traffic Engineering) will be described as an example, but the present invention is based on the protocol IETF RFC3472 CR-LDP (Constraint-based Routed Label Distribution Protocol) and ITU-T (International Telecommunications Standardization Department). The present invention can also be applied to other protocols such as ASON which is a protocol ITU-T G.7713 / Y.1704 established by the International Telecommunication Union-Telecommunication Standardization Sector.

  First, a configuration example of an optical network using the optical network device of the present embodiment will be described with reference to FIG. In FIG. 1, an optical network (4) includes optical network devices (1-1) to (1-6) connected to each other by optical fibers (3-01a to 3-11b) as transmission media. Composed. The optical network (4) is connected to routers (6-1) to routers (6-6) that serve as repeaters in the Internet. The present embodiment is configured by six optical network devices and 24 optical fibers, but the number and topology of these are arbitrary. As for the optical fiber, for example, a pair of the upstream / downward directions is used as in the pair of the optical fiber (3-01a) and the optical fiber (3-01b).

  An optical wavelength path is established by the optical network devices (1-1) to (1-6) exchanging GMPLS extended RSVP-TE messages with each other via the control information transfer network (5). The established optical wavelength path is used by the router (6-1) to the router (6-6).

  The control information transfer network (5) includes a control information transfer device (2-1) and a control information transfer device (2-2). As the control information transfer device (2-1) and the control information transfer device (2-2), a communication device such as an IP router or a Layer-2 switch can be used. In this embodiment, the control information transfer network (5) is composed of two control information transfer devices (2), but the number and topology thereof are arbitrary.

  An identifier for identifying each of the optical network devices (1-1) to (1-6) is given, and the identifiers are 192.168.1.1 to 192.168.1.6 in order.

  The configurations of the optical network device (1-1) to the optical network device (1-6) will be described with reference to FIGS. 2A and 2B. The optical network device (1-1) to the optical network device (1-6) include an edge switch type that transmits and receives optical signals between the router (6) and / or other optical network devices (1), and others. There is a core switch type that transmits and receives optical signals only between the optical network device (1). The optical network devices (1-1), (1-3) to (1-6) are edge switch types, and the optical network device (1-2) is a core switch type.

  FIG. 2A shows a configuration example of an edge switch type optical network device (1). 2A, an edge switch type optical network device (1) includes at least one edge interface unit 1 to m (103-1 to 103-m) and at least one core interface unit 1 to n (104-). 1 to 104-n), a switch unit (102), and a control unit (101). The optical fiber (3) is connected to the interface units (103) and (104), and the switch unit (102) exchanges (switches connection) the input / output optical signals of the interface units (103) and (104). Thus, the communication path is set. The operation (exchange) of the switch unit (102) is controlled by the control unit (101). The GMPLS extended RSVP-TE message is interpreted by the control unit (101).

  A configuration example of the core switch type optical network device (1) is shown in FIG. 2B. In FIG. 2B, the core switch type optical network device (1) does not have an edge interface unit, and controls at least one core interface unit 1 to n (104-1 to 104-n), a switch unit (102). Part (101). The optical fiber (3) is connected to the interface units (103) and (104), and the switch unit (102) exchanges (switches connection) the input / output optical signals of the interface units (103) and (104). Thus, the communication path is set. The operation (exchange) of the switch unit (102) is controlled by the control unit (101). The GMPLS extended RSVP-TE message is interpreted by the control unit (101).

  Here, in this embodiment, 32 wavelength multiplexing is used. The present invention is not limited to this, and the number of multiplexing depends on the wavelength multiplexing method to be used. Further, the multiplexing number may be different for each link.

  Also, identifiers are given to the edge interface unit (edge I / F unit) and the core interface unit (core I / F unit) of the optical network device (1), respectively. In the optical network device (1-1), (1001) is given to one edge I / F unit 1, and (2001) to (2003) are given to three core I / F units 1 to 3, respectively. In the optical network device (1-2), (2001) to (2004) are given to the four core I / F units 1 to 4, respectively. In the optical network devices (1-3) and (1-6), (1001) and (1002) are connected to the two core I / F units 1 and 2, respectively. (2001) and (2002) are given respectively.

  Next, the hardware configuration of the edge interface units 1 to m (103-1 to 103-m) will be described with reference to FIG. Each edge interface unit (103) includes a duplexer (33), an optical signal regenerator (34-01 to 34-64), an optical signal measuring device (35-01 to 35-64), and a wavelength converter (36- 01 to 36-32) and a multiplexer (38).

  The duplexer (33) receives the optical signal from the router (6) through the optical fiber (3), separates the received optical signal for each wavelength, and generates an optical signal regenerator (34-01 to 34- Send to 32). The optical signal regenerator (34-01 to 34-32) reproduces an optical signal by 2R that performs waveform shaping and amplification, or 3R that performs waveform shaping, amplification, and timing generation. Send to. The switch unit (102) transmits an optical signal to the core interface unit (104) or another edge interface unit (103) corresponding to the established optical wavelength path. The optical signal measuring device (35-01 to 35-32) measures the optical signal characteristics of the optical signal reproduced by the optical signal regenerator (34-01 to 34-32), and the measured value is controlled by the control unit (101). Send to. The optical signal regenerators (34-01 to 34-32) are controlled by the control unit (101) so as to set the compensation value of the optical signal characteristics.

  The wavelength converter (36-01 to 36-32) receives the optical signal from the core interface unit (104) or another edge interface unit (103) via the switch unit (102), and receives the received optical signal. The wavelength is converted into a wavelength corresponding to the optical wavelength path established based on the instruction from the control unit (101), and transmitted to the optical signal regenerator (34-33 to 34-64). The optical signal regenerator (34-33 to 34-64) regenerates the signal by 2R or 3R and transmits it to the multiplexer (38). The multiplexer (38) wavelength-multiplexes the plurality of received optical signals and transmits them to the router (6) via the optical fiber (3). The optical signal measuring device (35-33 to 35-64) measures the optical signal characteristics of the reproduced optical signal and transmits the measured value to the control unit (101).

  In this embodiment, after the optical signal is separated for each wavelength by the demultiplexer (33) in the edge interface unit (103), each of the 32 wavelengths is sent to the optical signal regenerator (34-01 to 34-32). Therefore, optical signal characteristic compensation is performed in units of wavelengths. The compensation target is the optical power of the optical signal, and the control parameter is the gain of the optical amplifier included in the optical signal regenerator (34).

  Next, the hardware configuration of the core interface units 1 to m (104-1 to 104-m) will be described with reference to FIG. Each core interface unit (104) includes an optical amplifier (amp) (41), a duplexer (42), an optical signal measuring device (43-01 to 43-64), and a wavelength converter (44-01 to 44-32). ) And a multiplexer (45).

  The optical amplifier (41) receives and amplifies an optical signal from the core interface unit (104) of another optical network device (1) via the optical fiber (3), and demultiplexes the amplified optical signal ( Send to 42). The gain of the optical amplifier (41) is set to an amount that cancels the attenuation of the optical fiber (3), the switch unit (102), etc. in the previous stage. The duplexer (42) separates the optical signal for each wavelength and transmits it to the switch unit (102). The switch unit (102) transmits an optical signal to the edge interface unit (103) or another core interface unit (104) corresponding to the established optical wavelength path. The optical signal measuring devices (43-01 to 43-32) measure the optical signal characteristics of the wavelength-separated optical signal and transmit the measured value to the control unit (101).

  The wavelength converter (44-01 to 44-32) receives the optical signal from the core interface unit (104) or the edge interface unit (103) via the switch unit (102), and receives from the control unit (101). The wavelength is converted into a wavelength corresponding to the optical wavelength path established based on the instruction, and transmitted to the multiplexer (45). The optical signal measuring devices (43-33 to 43-64) measure the optical signal characteristics of the wavelength-converted optical signal and transmit the measured value to the control unit (101). The multiplexer (38) wavelength-multiplexes the received plurality of optical signals and transmits them to the core interface unit (104) of the other optical network device (1) via the optical fiber (3).

  As described above, in the present embodiment, since the optical amplifier (41) is arranged before the duplexer (42) separates the optical signal for each wavelength, the core interface unit (104) has an edge interface unit ( The optical signal characteristic compensation in units of wavelengths performed in 103) is not performed.

  Next, the hardware configuration of the control unit (101) of the edge interface unit (103) and the core interface unit (104) will be described with reference to FIG. The control unit (101) includes a CPU (111), a memory (112), an internal communication line (113) such as a bus, a communication interface (114), and a device control interface (115).

  The communication interface (114) is connected to the control information transfer device (2) and exchanges GMPLS extended RSVP-TE messages with other optical network devices (1). The device control interface (115) is connected to the switch unit (102), the edge interface unit (103), and the core interface unit (104) and controls them or receives optical signal characteristic measurement values. The memory (112) stores a program (1121) and data (1122). The CPU (111) controls the communication interface (114) and the device control interface (115) according to the procedure described in the program (1121).

  Next, an example of the optical wavelength path established in the optical network (5) shown in FIG. 1 in the present embodiment will be described with reference to FIG. In FIG. 6, optical wavelength paths (7-1) to (7-3) are established. In FIG. 6, in order to show the optical wavelength paths (7-1) to (7-3), the letters and symbols shown in FIG. 1 in the optical network (5) are omitted.

  The optical wavelength path (7-1) is connected between the router (6-1) and the router (6-2) between the optical network device (1-1), the optical network device (1-2), and the optical network device (1). -3) has been established. The optical power on the path is +5.3 dBm in the core interface unit 1 (104-1) of the optical network device (1-2), and +4 in the core interface unit 1 (104-1) of the optical network device (1-3). .6 dBm.

  The optical wavelength path (7-2) is connected between the router (6-5) and the router (6-3) between the optical network device (1-4), the optical network device (1-1), and the optical network device (1 -2), the optical network device (1-3), and the optical network device (1-6). The optical power on the path is +4.6 dBm in the core interface unit 2 (104-2) of the optical network device (1-1), and +4 in the core interface unit 1 (104-1) of the optical network device (1-2). .5 dBm, +5.4 dBm in the core interface unit 1 (104-1) of the optical network device (1-3), and +7.2 dBm in the core interface unit 1 (104-1) of the optical network device (1-6). ing.

  The optical wavelength path (7-3) is connected between the router (6-6) and the router (6-4) between the optical network device (1-5), the optical network device (1-2), and the optical network device (1 -3), established through the optical network device (1-4). The optical power on the path is +4.6 dBm in the core interface unit 2 of the optical network device (1-5), +0.6 dBm in the core interface unit 1 (104-1) of the optical network device (1-2), and the optical network It is +0.2 dBm in the core interface unit 1 (104-1) of the device (1-3).

  Here, the optical wavelength path (7-1) and the optical wavelength path (7-2) pass through the core interface unit 1 (104-1) of the optical network device (1-2). The power is different from +5.3 dBm and +4.5 dBm, respectively. Similarly, the core interface unit 1 (104-1) of the optical network device (1-3) includes an optical wavelength path (7-1), an optical wavelength path (7-2), and an optical wavelength path (7-3). However, their optical powers are different from +4.6 dBm, +5.4 dBm, and +0.6 dBm, respectively. Further, the optical wavelength path (7-2) and the optical wavelength path (7-3) pass through the core interface unit 1 (104-1) of the optical network device (1-6). Are different from +7.2 dBm and +0.2 dBm, respectively. Even though the optical amplifier (41) of the core interface unit (104) is adjusted so as to cancel the attenuation at the immediately preceding link or switch (102), the level deviation between wavelengths is caused by the optical This is because the pass characteristics of optical devices such as the fiber (3), the optical amplifier (41), and the duplexer (42) have wavelength dependency.

  If the optical interface unit (104) and optical signal regenerator (34) that can control the gain for each wavelength are installed in the core interface unit (104) of each optical network device (1), the level deviation between wavelengths can be compressed. However, the optical network device (1) becomes large and expensive.

  In this embodiment, as will be described in detail below, the optical signal regenerator (34) capable of controlling the gain for each wavelength can be installed only in the edge interface unit (103). Gain adjustment is controlled. As a result, the number of optical signal regenerators (34) is reduced, and miniaturization and cost reduction of the optical network device (1) are achieved. When the network size is increased, the optical signal regenerator (34) may be installed in a part of the core interface unit (104). Also in this case, since the core interface unit (104) in which the optical signal regenerator (34) is installed is limited, the number of optical signal regenerators (34) in the entire network is reduced. In the following, the case where the optical wavelength path shown in FIG. 6 is established will be described. However, the compression of the inter-wavelength level deviation performed by limiting the number of optical signal regenerators (34) is a reserved type path. It is also applicable when the path changes dynamically due to establishment, traffic engineering, path failure recovery, etc.

  6, in the optical wavelength path (7-3), the core interface unit 1 (104) of the optical network device (1-3) and the core interface unit 1 (104) of the optical network device (1-6). An operation example for compressing the inter-wavelength level deviation will be described with reference to FIG.

  The control information for compressing the inter-wavelength level deviation in this embodiment includes a new object in the PATH message and the RESV (Reserve) message in the refresh sequence after the basic path establishment of GMPLS extended RSVP-TE. Thus, they are exchanged between the optical network devices (1). The PATH message is a message requesting allocation of a communication path from the transmission side to the reception side, and the RESV message is a message notifying the communication path set in response to this from the reception side to the transmission side.

  The RESV message carries an extended route record object (hereinafter referred to as “EX_RRO; Extended Record Route Object”) according to the present invention. EX_RRO represents “optical signal measurement / reproduction related information” of the optical wavelength path. Information related to optical signal measurement / regeneration is the measurement point of the optical signal measuring instrument, the optical signal regenerator, the interface identifier, the order relationship on the path, the measured value of the optical signal measuring instrument, and the compensation through which the optical wavelength path passes. `` Control necessity judgment threshold '' indicating the condition for judging whether or not the value needs to be changed, `` Target value '' that is the optimum value that the measurement result should originally take, the settable range of the optical signal regenerator and the current set value This is a grouped information.

  In EX_RRO, optical signal measuring device identification information, control necessity judgment threshold value, and measurement value are added as in normal RRO (Record Route Object) to which identification information of the passing interface in GMPLS extended RSVP-TE is added. Furthermore, the identification information of the optical signal regenerator, the settable range, and the current set value are additionally written. The EX_RRO added in this way is transferred from the receiving side to the upstream optical network device (1).

  In the optical wavelength path (7-3), an optical network device (1-5) (identifier: 192.168.1.5) to an optical network device (1-2) ( The PATH message of sequence 1001 is sent to the identifier: 192.168.1.2). Subsequently, a PATH message of sequence 1002 is sent from the optical network device (1-2) to the optical network device (1-3) (192.168.1.3). Further, a PATH message of sequence 1003 is sent from the optical network device (1-3) to the optical network device (1-6) (192.168.1.6).

  Next, a RESV message loaded with information related to optical signal measurement / reproduction is returned upstream from the receiving side that has received the PATH message requesting communication path allocation. For example, the value in the own node which is the optical network device (1-6) is stored in the RESV message of the sequence 1004 from the optical network device (1-6) to the optical network device (1-3). That is, the first core interface unit (104) to be used is represented by (inf, (192.168.1.6, 2001)). In addition, the measured value of the optical power that should be the control necessity determination threshold value +3 to +9 dBm and the target value +6 dBm of the first wavelength selected by the core interface unit is +0.2 dBm (power_meter, (192.168.1.6, 2001, 1), (3, 6, 9), +0.2). The current value of the amplifier gain of the optical signal regenerator for the first wavelength for the first wavelength in the edge interface unit 103) to be used is 3 dB (regen, (192.168.1.6, 1002, 1), (-6, 20), 3). Subsequently, the value in the local node that is the optical network device (1-3) is added to the RESV message of the sequence 1005 from the optical network device (1-3) to the optical network device (1-2). . That is, the first core interface unit (104) to be used is represented by (inf, (192.168.1.3, 2001)). The measured value of the optical power of the first wavelength selected by the core interface unit is +0.6 dBm (power_meter, (192.168.1.6, 2001, 1), (3, 6, 9), +0.6 ). Further, the value in the own node that is the optical network device (1-2) is further added to the RESV message of the sequence 1006 from the optical network device (1-2) to the optical network device (1-5). That is, the second core interface unit (104) to be used is represented by (inf, (192.168.1.2, 2002)). In addition, the measured value of the optical power of the first wavelength selected by the core interface unit is +4.6 dBm (power_meter, (192.168.1.2,2002,1), (3,6,9), +4.6).

  When making additional writing, each connection relationship is maintained. As a result, the optical network device (1-5) obtains these values and connection relations in the end-to-end section of the path.

  The optical network device (1-5) that is the starting point of the optical wavelength path determines the compensation value on the optical wavelength path route (1011), and if it is determined that a setting change in its own node is necessary Changes are made (1012). For example, the amplifier gain of the optical signal regenerator, which was 3 dB, is changed to 6 dB. If it is determined that a setting change in the downstream node is necessary along with this change, optical signal compensation control information is created, stored in EX_ERO, and a PATH message is transmitted. For example, each core of the optical network devices (1-2), (1-3), and (1-6) is included in the PATH message of the sequence 1021 from the optical network device (1-5) to the optical network device (1-2). Interface part (inf, (192.168.1.2,2002)), (inf, (192.168.3,2001)), (inf, (192.168.1.6,2001)) is stored, and the optical network device (1-6) Control information (regen, (192.168.1.6, 1002, 1), 0) for setting the amplifier gain of the 3 dB optical signal regenerator to 0 dB is stored.

  The optical network device that received the EX_ERO object changes the compensation setting value based on that if it is recorded that control in its own node is necessary, deletes its own sub-object, and transfers the EX_ERO object downstream. (1022 to 1023). EX_ERO expresses a compensation value to be newly set in each optical network device through which the optical wavelength path passes. Here, the optical signal compensation control information is a set of an identifier of a compensator whose setting is to be changed and a new compensation value.

  In this example, only the regen sub-object is stored for the optical network device (1-6), so only the optical network device (1-6) sets the amplifier gain of the optical signal regenerator (34). The value is changed from 3 dB to 0 dB (1031). Since the amplifier gain has increased by 3 dB in the upstream (optical network device (1-5)), the optical power value in the RESV message of sequences 1041 to 1043 from the optical network device (1-6) to the upstream is sequence 1004. It is displayed 3 dB higher than in the case of ~ 1006. That is, the optical powers in the optical network devices (1-6), (1-3), and (1-2) are displayed as +3.2 dBm, +3.6 dBm, and +7.6 dBm, respectively. Thereafter, the above operation is repeated.

  In the network configuration of FIG. 6, only the edge interface unit (103) includes the optical signal regenerator (34) in wavelength units, so only the optical network device (1-6) stores the regen sub-object in the EX_ERO object. However, if the intermediate node includes an optical signal regenerator (34) in units of wavelengths, that node may be additionally written. For example, the optical network device (1-3) may add a regen sub-object. In this case, the compensation value for this is specified by, for example, the EX_ERO object by the origin node. Alternatively, the compensation value may be controlled not in the end-to-end interval but in the interval between the optical network device (1-3) and the optical wavelength path end point based on the determination of the optical network device (1-3).

  Next, the software configuration of the control unit (101) that generates the signal compensation control information of the present invention and performs compensation control will be described with reference to FIG. The software is formed by a program (1121) and data (1122) that define the operation procedure of the CPU (111) in FIG. The software of the control unit (101) includes an interface configuration table (1201), an optical amplifier specification table (1202), an optical measuring instrument specification and monitoring condition table (1203), a measurement value acquisition unit (1204), and a signaling processing unit (1205). The compensation control content determination unit (1206) and the compensation control unit (1207) are included.

  The interface configuration table (1201) holds the connection relationship between the interface units (103) and (104), the optical signal regenerator (34), and the optical signal measuring devices (35) and (43) in its own device. The optical amplifier specification table (1202) holds a settable parameter, a settable range, and the like as information on the optical amplifier (41) and the optical signal regenerator (43) in its own device. The optical measuring instrument specification and monitoring condition table (1203) is the information about the optical signal measuring instrument (35), (43) in its own device, and it is possible to perform control by changing the target value that the measurement value should originally take and the parameter change. A threshold for determining necessity is stored. Examples of the interface configuration table (1201), the optical amplifier specification table (1202), the optical measuring instrument specification and the monitoring condition table (1203) will be described later with reference to FIGS.

  The measurement value acquisition unit (1204) acquires measurement values from the optical signal measuring devices (35) and (43), and provides the measurement values in accordance with a request from the signaling processing unit (1205). Alternatively, when the value changes beyond the threshold, the signaling processor (1205) is notified that the threshold has been exceeded, even if there is no request from the signaling processor (1205).

  The compensation control unit (1207) updates or acquires the operation parameters of the optical signal regenerator (34) and the optical amplifier (41) based on a request from the signaling processing unit (1205) to obtain the signaling processing unit (1205). To provide.

  Based on the request from the signaling processing unit (1205), the compensation control content determination unit (1206) derives the optical signal compensation control information using the optical signal measurement / reproduction related information and provides it to the signaling processing unit (1205). Details of the compensation amount determination processing of the compensation control content determination unit (1206) will be described later with reference to FIG.

  The signaling processing unit (1205) establishes / releases an optical wavelength path by exchanging PATH / RESV messages based on the GMPLS extended RSVP-TE standard and controlling the switch unit (102) based on the PATH / RESV message. Also, when sending and receiving RESV messages, refer to the optical amplifier specification table (1202), optical measuring instrument specification and monitoring condition table (1203), and the optical signal regenerator (34) related to the optical wavelength path being processed. Information on the optical signal measuring devices (35) and (43) is derived, and the current set value is obtained from the optical signal regenerator (34) via the compensation control unit (1207), and is transmitted via the measured value acquisition unit (1204). Measurement values are acquired from the signal measuring instruments (35) and (43), respectively. Further, by referring to the interface configuration table (1201), the connection relationship between the optical signal regenerator (34), the optical signal measuring devices (35) and (43), and the interface units (103) and (104) is derived. The information related to the optical signal measurement / reproduction is derived by arranging the information on the optical signal regenerator (34) and the optical signal measuring instruments (35), (43), the current set value, and the measured value in order. The signaling processing unit (1205) loads the derived optical signal measurement / reproduction related information on the RESV message as an EX_RRO object and transfers it to the optical network device (1) upstream of the optical wavelength path.

  The signaling processing unit (1205) also instructs the measurement value acquisition unit (1204) to determine whether or not the compensation operation is necessary when receiving EX_RRO. If determined to be necessary, based on the optical signal measurement and reproduction related information received from the measurement value acquisition unit (1204), control the optical signal regenerator (34) in its own device to the compensation control unit (1207). At the same time, the optical signal measurement / reproduction related information is set as an EX_ERO object in the PATH message and transferred to the downstream optical network device.

  Next, the contents of the optical wavelength path optical signal measurement and reproduction related information acquired by the optical network device (1-5) in the sequence 1006 of FIG. 7 will be described with reference to FIG.

  The optical network device (1-5) has an interface unit (104) (1111) with an identifier (192.168.1.2, 2002) immediately downstream from the EX_ERO of the sequence 1006, and the identifier is (192.168.1.2, 2002, 1) There is a value of the optical power meter (1112) that is the optical signal measuring instrument (43) for the first wavelength, and the interface part (104) (1121) with the identifier (192.168.1.3,2001) is Yes, there is a value of the optical power meter (1122), which is the optical signal measuring device (43) for the first wavelength, with the identifier (192.168.1.3,2001,1), and the identifier is (192.168.1.6,2001 ) Interface part (104) (1131), identifier (192.168.1.6, 2001, 1), optical power meter (1132), identifier (192.168.1.6, 1002, 1) for the first wavelength It is possible to know that these exist in this order.

  In addition, the optical network device (1-5) refers to the session information of the GMPLS extended RSVP-TE of its own node, the interface configuration table (1201), and the optical amplifier specification table (1202), so that the interface unit (104) It can be known that the optical signal regenerators (34) and (1101) exist upstream of (1111) (in this case, the own node). The identifier of the optical signal regenerator (34) is (192.168.1.5, 1002, 1). For the optical signal regenerator (1101, 1133), the settable range (-6 dB to 20 dB) and the current set value (3 dB) can be known.

  In addition, regarding the optical power meter (1112, 1122, 1132), control necessity determination threshold values (+3 dBm, +9 dBm), target values (+6 dBm), and actual measurement values (+4.6 dBm, +0.6 dBm, +0.2 dBm, respectively). I can know. The measured value is compared with the control necessity judgment threshold value, and if the former is within the latter range, control is not necessary, and if it is out of the range, it is necessary to change the amplifier gain parameter of the optical signal regenerator (34). It can be judged that there is. In the example of this figure, at two points of the optical power meter (1122, 1132), the measured values are outside the control necessity determination threshold value range, and it is necessary to change the parameters of the optical signal regenerator (34). It is judged.

  In order to change these actually measured values, the parameters of the optical signal regenerator existing on the upstream side may be changed. In the example of this figure, it can be known that the parameter of the optical signal regenerator (1101) should be changed. It can also be seen that changing the parameters of the optical signal regenerator (1101) may affect the optical power meter (1112, 1122, 1132) and further downstream of the optical signal regenerator (1133). From the above, it can be seen that the parameters of the optical signal regenerator (1133) may be changed in the optical signal regenerator (1133) so as to cancel the influence of the parameter change of the optical signal regenerator (1101).

Next, the structure of the interface configuration table (1201) will be described with reference to FIG. The interface configuration table (1201) holds the connection relationship between the interface units (103) and (104), the optical signal regenerator (34), and the optical signal measuring devices (35) and (43) in its own device.

  The interface configuration table (1201) has columns of an upstream device (701) and a downstream device (702). The upstream device (701) is further divided into columns of type (7011) and local identifier (7012). The downstream device (702) is similarly divided into columns of type (7021) and local identifier (7022).

  The example of the stored value in this figure shows the interface configuration table (1201) held by the optical network device (1-4) in FIG. 1, and all edge interface units (in the optical network device (1-4)) ( 103) and a connection relationship between the optical signal measuring devices (35) and (43) and the optical signal regenerator (34) of the core interface unit (104). That is, in the connection relationship (703), the connection relationship of the optical signal measuring devices (3501 to 3532) corresponding to the wavelengths 1 to 32 (λ1 to λ32) of the first (1001) edge interface unit (103-1). Is shown. The connection relationship (704) shows the connection relationship of the optical signal measuring devices (3533 to 3564) corresponding to the wavelengths 1 to 32 (λ1 to λ32) of the first (1001) edge interface unit (103-1). It is. In the connection relationship (705), the connection relationship of the optical signal measuring devices (3533 to 3564) corresponding to each of the optical signal regenerators (34-01 to 34-32) is shown. The connection relationship (706) shows the connection relationship of the optical signal measuring devices (4301 to 4332) corresponding to the wavelengths 1 to 32 (λ1 to λ32) of the core interface unit (104-1) of the first (2001). It is. The connection relation (707) shows the connection relation of the optical signal measuring instruments (4333 to 4364) corresponding to the wavelengths 1 to 32 (λ1 to λ32) of the core interface unit (104-1) of the first (2001). It is.

  Next, the structure of the optical amplifier specification table (1202) will be described with reference to FIG. The optical amplifier specification table (1202) holds settable parameters, settable ranges, and the like as information about the optical amplifiers included in the optical amplifier (41) and the optical signal regenerator (34) in its own device.

  The optical amplifier specification table (1202) includes an amplifier identifier (801) that indicates which optical amplifier, an amplification unit that indicates whether an optical signal from an optical fiber (fiber) or an optical signal for each wavelength (lambda) is amplified ( 802), control target parameters, and controllable range (803). In the column of the amplifier identifier (801), in order from the top, the optical amplifier (41) of the first (2001) core interface (104-1) and the optical signal regenerator (34-01 to 34-) of the first (1001). 64) Optical amplifier is shown.

  Next, the structure of the optical measuring instrument specification and monitoring condition table (1203) will be described with reference to FIG. The optical measuring instrument specification and monitoring condition table (1203) is used to determine whether or not it is necessary to perform control by changing the target value that should be originally taken as the measured value as information about the optical signal measuring instrument in its own device. Holds thresholds and the like.

  The optical measuring instrument specification and monitoring condition table (1203) includes a measuring instrument type (901) indicating the type to be measured, a measuring instrument identifier (902) indicating the distinction between the optical signal measuring instruments (35) and (43), and a measurement. Each column includes a unit (903), a target value (904), a control necessity determination threshold value (905), and an abnormality determination threshold value (906).

  Next, the compensation amount determination process executed by the compensation control content determination unit (1206) in the sequence 1011 of FIG. 7 will be described with reference to FIG. This process is started when the signaling processor (1205) receives the RESV message and EX_RRO is included in the received message.

  Optical signal measurement and reproduction related information is received from the signaling processing unit (1205) (1301), and it is determined whether or not a measurement point that exceeds the control necessity determination threshold is included (1302). If it is not included, the process ends.If it is included, it is determined using the optical amplifier specification table (1202) whether the own apparatus has an optical signal regenerator capable of compensating for the measurement value exceeding the determination threshold. (1303). If it does not have it, it will end, if it has it (the power of all nodes on the route will be in the warning value range) and (the sum of the deviation from the target value will be minimum), control parameters will be determined and the optical signal compensation control information will be Is generated (1304). The optical signal compensation control information is passed to the signaling processing unit (1205).

  In this embodiment, the object to be compensated is the optical power, and therefore the control parameter is the amplifier gain. However, the present invention is not limited to the S / N ratio, the dispersion of the optical propagation group delay, the polarization dispersion, and the dispersion mode. Delay, Q factor, etc. can be targeted for compensation. In that case, control parameters corresponding to each are set.

  As described above, according to the present embodiment, it is possible to eliminate the optical signal characteristic deviation between wavelengths without providing a compensator that performs optical signal characteristic compensation for each wavelength, for example, an optical signal regenerator in all network devices. . Further, even when the path changes dynamically due to reservation-type path establishment, traffic engineering, path failure recovery, etc., it becomes possible to eliminate the optical signal characteristic deviation between wavelengths.

DESCRIPTION OF SYMBOLS 1 ... Optical network apparatus, 2 ... Control information transfer apparatus, 3 ... Optical fiber, 4 ... Optical network, 5 ... Control information transfer network, 6 ... Router, 33, 42 ... Demultiplexer, 34 ... Optical signal regenerator, 35 , 43 ... Optical signal measuring device, 36, 44 ... Wavelength converter, 38, 45 ... Multiplexer, 41 ... Optical amplifier, 101 ... Control part, 102 ... Switch part, 103 ... Edge interface part, 104 ... Core interface part 111 ... CPU, 112 ... memory, 113 ... internal communication line, 114 ... communication interface, 115 ... device control interface, 1121 ... program, 1122 ... data.

Claims (14)

An optical network device for configuring an optical network using an optical fiber as a transmission medium,
An interface unit connected to the optical fiber;
By switching the connection for the input / output optical signal of the interface unit, a switch unit for setting a communication path;
An optical signal measuring instrument for measuring the characteristics of the optical signal;
A control unit for controlling the operation of the switch unit based on a control message for establishing a communication path transmitted in accordance with a communication path establishment control protocol,
The interface optical network device and transmits the other optical network devices using a control message of the upper Symbol Communication path establishment control protocol the measured value measured by the optical signal measuring instrument. The optical network device according to claim 1, wherein
Based on the collected measurement values, the optical network device arranged at the starting point of the communication path gives an instruction to control parameters of other optical network apparatuses by a control message transmitted using the communication path establishment control protocol. An optical network device for transmitting. The optical network device according to claim 1, wherein
The communication path optical network unit arranged on the origin of, the control message transmitted using the communications path establishment control protocol, type AND / OR range of the optical signal regenerators that can control parameters of the optical network device An optical network device that collects The optical network device according to claim 1, wherein
An optical signal regenerator that compensates for the characteristics of the optical signal by changing control parameters;
The optical network apparatus, wherein the control parameter is set in the optical signal regenerator using the communication path establishment control protocol. The optical network device according to claim 1, wherein
An optical network device characterized in that a value of the control parameter is determined based on the measured value transmitted to the other optical network device. The optical network device according to claim 1, wherein
The optical network device downstream of the set communication path transmits the optical signal measurement and reproduction related information to the upstream optical network device by the communication path establishment control protocol, and the upstream optical network device transmits the optical network on the communication path. An optical network device characterized by receiving information relating to optical signal measurement / reproduction cumulatively added by the device. The optical network device according to claim 6, wherein
The optical signal measurement / reproduction related information includes, on the set communication path, the measurement points of the optical signal measuring instrument, the respective identifiers of the optical signal regenerator and the interface unit, the order relationship on the communication path,
The measurement value of the optical signal measuring instrument, the control necessity judgment threshold indicating the condition for judging whether or not the compensation value needs to be changed, the target value that is the optimum value that the measurement result should originally take , and the setting of the optical signal regenerator An optical network device characterized in that it represents information obtained by combining a possible range and a current set value. The optical network device according to claim 6, wherein
When the upstream optical network device includes a measurement value that exceeds the control necessity determination threshold included in the received optical signal measurement / reproduction related information, the measurement value that exceeds the control necessity determination threshold The optical signal regenerator capable of compensating for the optical signal is determined, and if it is provided, the control parameter is determined, the optical signal measurement / reproduction related information is generated, and the setting of the device is changed. Network device. The optical network device according to claim 8, wherein
When the upstream optical network device changes its own setting based on the optical signal measurement / reproduction related information, if the setting of the downstream optical network device needs to be changed, the upstream optical network device uses the communication path establishment control protocol. An optical network device, wherein information is transmitted to the downstream optical network device. An optical network system comprising at least a first optical network device and a second optical network device in a network,
Each of the above optical network devices constitutes an optical network using an optical fiber as a transmission medium,
The first optical network device includes:
An interface unit connected to the optical fiber;
By switching the connection for the input / output optical signal of the interface unit, a switch unit for setting a communication path;
An optical signal measuring instrument for measuring the characteristics of the optical signal;
A control unit for controlling the operation of the switch unit based on a control message for establishing a communication path transmitted in accordance with a communication path establishment control protocol,
The interface optical network system and transmits to the second optical network using a control message of the upper Symbol Communication path establishment control protocol the measured value measured by the optical signal measuring instrument. The optical network system according to claim 10, wherein
The optical network device downstream of the set communication path transmits the optical signal measurement / reproduction related information to the upstream optical network device using the communication path establishment control protocol, and the upstream optical network device transmits the optical signal on the communication path. An optical network system for receiving optical signal measurement / reproduction related information cumulatively added by a network device. The optical network system according to claim 11, wherein
The optical signal measurement / reproduction related information includes, on the set communication path, the measurement points of the optical signal measuring instrument, the respective identifiers of the optical signal regenerator and the interface unit, the order relationship on the communication path,
The measurement value of the optical signal measuring instrument, the control necessity judgment threshold indicating the condition for judging whether or not the compensation value needs to be changed, the target value that is the optimum value that the measurement result should originally take , and the setting of the optical signal regenerator An optical network system characterized in that it represents information obtained by combining a possible range and a current set value. The optical network system according to claim 12, wherein
When the upstream optical network device includes a measurement value that exceeds the control necessity determination threshold included in the received optical signal measurement / reproduction related information, the measurement value that exceeds the control necessity determination threshold The optical signal regenerator capable of compensating for the optical signal is determined, and if it is provided, the control parameter is determined, the optical signal measurement / reproduction related information is generated, and the setting of the device is changed. Network system. The optical network system according to claim 13, wherein
When the upstream optical network device changes its own setting based on the optical signal measurement / reproduction related information, if the setting of the downstream optical network device needs to be changed, the upstream optical network device uses the communication path establishment control protocol. An optical network system, wherein information is transmitted to the downstream optical network device.

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