JP5821644B2 - Optical signal repeater and optical communication network system - Google Patents

Description

    The present invention relates to an optical signal repeater and an optical communication network system, and can be applied to an optical communication network system such as a PON (Passive Optical Network).

  A communication system (communication network) in which a conventional communication carrier (for example, an ISP operator) accommodates a user network has a normal hierarchical structure. In the communication system of the conventional communication carrier, for example, the main line, the branch line network, and the access network are hierarchized from the top. The above-mentioned “trunk network” is composed of, for example, a trunk node station and a trunk optical transmission line connecting the trunk node stations. The above-mentioned “branch network” is composed of, for example, branch line node stations and branch line optical transmission lines connecting between branch line node stations, and is connected to the trunk network at a node representing the branch line network. As a typical network configuration for realizing the above-mentioned “access network”, there is a PON configuration in which a single optical fiber is branched into a plurality of branches and connected to a plurality of user networks. An access network adopting a PON configuration includes a station side device (OLT: Optical Line Terminal) installed in a branch node station, a subscriber side device (ONU: Optical Network Unit) installed in a user's home, and both. And an access optical transmission line to be connected. In a PON constituting a conventional access network, a passive double star type using a splitter that divides and couples the power of an optical signal is often used. Also, in a PON constituting a conventional access network, a method using time division multiplexing (TDM) is currently widely used as a method for multiplexing signals between OLT and ONU. Examples of conventional PON using TDM (TDM-PON) include EPON standardized by IEEE, GE-PON standardized by ITU-T (Gigabit Ethernet (registered trademark) PON), and the like.

  In an access network using a conventional PON, a plurality of OLTs serving as master station side devices are arranged in branch node stations. Under each OLT, a network (hereinafter referred to as a “PON branch”) connected to a plurality of ONUs (ONU group) by branched access optical transmission lines (including splitters) is configured. The

  By the way, in the PON constituting the access network, “multi-branch” and “longer transmission distance” of the access optical transmission path are required.

  First, “multi-branching” of PON will be described. For example, when there are few users in an area where one PON branch is formed, the OLT is shared by a small number of users, which is expensive. Therefore, when the number of users in the PON branch is small, it is desirable to perform communication using a single OLT by combining a plurality of PON branches. In this way, connecting a plurality of PON branches together to one OLT is called “multi-branching” of the PON. However, in order to perform multi-branching of the PON, it is necessary to further connect the branches with a splitter. Since the splitter attenuates the power of the optical signal, if the number of branches becomes excessive, the transmission line loss between the OLT and the ONU may exceed an allowable value (referred to as a loss budget).

  Next, “long distance” of PON will be described. As described above, in the communication system of the conventional communication carrier, the OLT is usually installed in the branch node station. However, the installation of this OLT in a trunk node station has been studied in the past. In this way, the OLT is installed in the trunk node station, and the terminal on the parent station side of the PON branch is not a branch node station but a trunk node station, and the distance of the PON branch is increased. Called " As described above, by extending the distance of the PON, it is possible to concentrate the OLTs distributed in each branch node station on the trunk node stations, thereby simplifying device management and reducing operating costs. it can. In addition, by increasing the distance of the PON, the number of devices installed in the branch node station is reduced, so that it is not necessary to prepare a large branch node station facility, and a reduction in operation cost can be expected. However, as the transmission distance of the PON increases, the loss of the transmission path increases as the transmission distance increases, which may exceed the loss budget.

  Therefore, it is necessary to expand the loss budget in the PON branch in order to perform “multi-branching” and “long distance” of the PON. As a conventional method for expanding the loss budget of the PON branch, for example, there is a method using an optical amplifier (see Non-Patent Document 1). Non-Patent Document 1 describes a method of relaying optical signals in a PON branch of GE-PON using an optical amplifier.

  In Non-Patent Document 1, an uplink signal (signal going from ONU to OLT) and a downlink signal (signal going from OLT to ONU) are separated by a WDM filter in the branch node station, and the uplink signal and the downlink signal are respectively separated by an optical signal amplifier. Amplified and sent to the destination. As described above, in Non-Patent Document 1, the loss budget is expanded by compensating for the loss caused by the PON having a long distance or multi-branching by the optical signal amplifier.

  By the way, the downstream signal in the conventional GE-PON (TDM-PON) is a continuous signal having a constant optical power. Therefore, Non-Patent Document 1 describes that a downstream signal in GE-PON needs to be amplified by a continuous signal optical amplifier. On the other hand, the upstream signal in the conventional GE-PON (TDM-PON) becomes an intermittent burst signal with uneven optical power. Therefore, Non-Patent Document 1 describes that the upstream signal needs to be amplified by the burst signal optical amplifier.

Takeyuki Imai, Masamitsu Fujiwara, Katsuhisa Taguchi, Kenichi Suzuki, “Outdoor PON Optical Amplifier”, IEICE Technical Report, vol.111, no.117, CS2011-14, pp. 23-27, July 2011, published by IEICE

  However, the long-distance multi-branch PON using an optical signal amplifier as a repeater as described in Non-Patent Document 1 has the following problems.

  A first problem in the technology described in Non-Patent Document 1 is that an optical amplifier for burst signal for stably amplifying an optical burst signal is not practically used at present. The optical power of the optical burst signal is discontinuous in time. Therefore, in order to amplify the optical burst signal without deterioration of the waveform, it is necessary to control the amplification factor in a complicated manner. A technique for solving this problem has not yet been established, and even if it is realized, there is a risk that the cost will be high.

  A second problem in the technology described in Non-Patent Document 1 is that it is difficult to increase the communication band. When the number of ONUs connected to the OLT increases or when the communication band per ONU increases, the PON communication band becomes insufficient. In this case, an OLT or ONU having a wider communication band must be used. In this case, it is necessary to replace all installed OLTs and ONUs, and the apparatus installation cost increases.

  A third problem in the technology described in Non-Patent Document 1 is that power utilization efficiency is poor. When the distance of the PON branch is relatively short or when the number of branches of the PON branch is relatively small, there is a case where it is not necessary to amplify at the branch node station. However, Non-Patent Document 1 describes that all signals are amplified regardless of the necessity of such signal amplification. Therefore, in the PON using the technology described in Non-Patent Document 1, the use of power may be inefficient.

  A fourth problem in the technology described in Non-Patent Document 1 is that there is a possibility that a failure cannot be avoided. For example, in a PON using the technology described in Non-Patent Document 1, when a branch network fiber is cut or an OLT fails, communication of all ONUs connected to the OLT is stopped.

  In view of the above problems, an optical signal capable of realizing a long-distance and multi-branch transmission path between a master station communication device (for example, OLT) and a slave station communication device (for example, ONU). Relay device and optical communication network system

  The first aspect of the present invention includes one or more master station communication devices, one or more master station communication devices, one or more slave station communication devices connected to a branched optical transmission line and a branch destination of the optical transmission line. In an optical signal repeater that relays an optical signal to and from an optical access network, (1) it has a plurality of optical communication ports that transmit and receive optical signals, and an optical signal input to one of the optical communication ports A plurality of optical communication ports are output from other optical communication ports corresponding to the wavelength of the signal, and each of the plurality of optical communication ports includes a first group including an optical communication port for connecting to each of the master station communication devices. A second group including an optical communication port for connecting to an optical transmission line of the optical access network, and a second group including an optical communication port for transmitting and receiving an optical signal to and from the optical communication port of the first communication port group. 3 groups and the second group Optical wavelength routing means divided into a fourth group including optical communication ports for transmitting and receiving optical signals and (4) optical communication ports for transmitting and receiving electrical signals. An electric signal exchange means for outputting an electric signal input to any one of the telecommunication ports from another telecommunication port according to the setting; (3) each optical communication port belonging to the third group; First signal converting means for performing conversion processing between an electric signal and an optical signal with the electric communication port of the electric signal exchanging means; and (4) each optical communication belonging to the fourth group. And a second signal conversion means for performing a conversion process between an electrical signal and an optical signal between the port and the electrical communication port of the electrical signal exchange means.

  The second aspect of the present invention includes one or a plurality of master station communication devices, one or a plurality of slave station communication devices connected to a branched optical transmission path and a branch destination of the optical transmission path. In an optical communication network system comprising an optical access network and an optical signal relay device that relays an optical signal between the master station communication device and the optical access network, the optical signal relay device according to the first aspect of the present invention A signal relay device is applied.

  According to the present invention, it is possible to realize a long-distance and multi-branch transmission path between a master station communication device and a slave station communication device.

It is the block diagram shown about the whole structure of the optical communication network system of 1st Embodiment. It is explanatory drawing shown about the operation rule of AWGR of 1st Embodiment. It is the block diagram shown about the functional structure of OLT which concerns on 1st Embodiment. It is the block diagram shown about the functional structure of ONU which concerns on 1st Embodiment. It is explanatory drawing shown about the specific example of the routing table applied to AWGR which concerns on 1st Embodiment. It is the block diagram shown about the 1st setting structural example of the optical communication network system which concerns on 1st Embodiment. It is the block diagram shown about the 2nd setting structural example of the optical communication network system which concerns on 1st Embodiment. It is the block diagram shown about the 3rd setting structural example of the optical communication network system which concerns on 1st Embodiment. It is the block diagram shown about the whole structure of the optical communication network system which concerns on 2nd Embodiment.

(A) First Embodiment Hereinafter, a first embodiment of an optical signal relay device and an optical communication network system according to the present invention will be described in detail with reference to the drawings.

(A-1) Configuration of the First Embodiment FIG. 1 is a block diagram showing the overall configuration of the optical communication network system 1 of this embodiment.

  In the optical communication network system 1, one or a plurality of OLTs 10 (10-1 to 10-N) are arranged in a trunk node station. Each OLT 10 is an optical fiber (hereinafter also referred to as “branch line optical transmission line”) and is connected to the optical signal repeater 30 arranged in the branch node station.

  An optical fiber (hereinafter also referred to as “access optical transmission line”) of a plurality of PON branches 50 (50-1 to 50-M) is connected to the optical signal repeater 30 disposed in the branch node station. . In each PON branch 50, a plurality of optical fibers connected to the optical signal repeater 30 side are branched by an optical splitter 40, and the ONU 20 is connected to each branched optical fiber. Each ONU 20 is, for example, arranged at each user base. The number of PON branches 50 accommodated in the optical signal relay device 30 and the number of ONUs 20 arranged in each PON branch 50 are not limited. Further, in FIG. 1, N = M is assumed to facilitate the description of the internal configuration of the optical signal relay device 30, but N and M may be different numbers.

  Each PON branch 50 is accommodated in one of the OLTs 10 via the optical signal relay device 30. Although details will be described later, in the optical communication network system 1, the OLT 10 may accommodate a plurality of PON branches 50. Although the PON standard supported by the optical communication network system 1 is not limited, in this embodiment, as an example, a GE-PON using the technology of IEEE 802.3ah is formed under each OLT 10. Shall.

  That is, as shown in FIG. 1, in the optical communication network system 1, the OLT 10 is installed not in the branch node station but in the higher node, which is a higher-level station, so It is the composition which realizes.

  Each OLT 10 is connected via a core transmission device 60 to a higher-level core network (master station side network) (not shown). The communication method of the core transmission device 60 is not limited. For example, a router or an L3 switch compatible with Ethernet (registered trademark) can be applied. The configuration in which the OLT 10 is connected to the core network is not limited. On the other hand, a lower-level user network (slave station side network) (not shown) is connected to each ONU 20. That is, each ONU 20 is connected to a communication device (for example, a communication device such as a router, a switch device, or a computer) constituting a subordinate user network. The number of OLTs 10 installed in the optical communication network system 1 and the number of ONUs 20 subordinate to each OLT 10 are not limited.

  In the following, the direction toward the trunk node station side (OLT 10 side) is referred to as the upstream direction (upstream side), and the direction toward the PON branch 50 (ONU 20) is referred to as the downstream direction (downstream side).

  Moreover, although mentioned later for details, OLT10 in which each PON branch 50 is accommodated can be changed according to the setting of each apparatus which comprises the optical communication network system 1. FIG. That is, the optical communication network system 1 has a configuration in which the OLT 10 that accommodates each PON branch 50 can be changed by changing the setting of each device after installation.

  In the optical communication network system 1, a control terminal 70 used by a system administrator or the like is connected to the core transmission device 60, and each device (OLT 10, ONU 20, It is also possible to change the setting for the optical signal repeater 30). The route and protocol connected from the control terminal 70 to each device (OLT 10, ONU 20, and optical signal relay device 30) are not limited, and various connection configurations can be employed. For example, when the control terminal 70 is connected to each OLT 10, for example, the control signal may be transmitted and received by direct IP connection via the core transmission device 60. Further, for example, when the control terminal 70 connects to each ONU 20, the connection control may be performed based on the OAM from the OLT 10 that accommodates the ONU 20. Further, for example, when the control terminal 70 is connected to the optical signal relay device 30, for example, a control signal line (for example, an optical fiber) or a radio line may be separately prepared and connected. The connection may be made in the same manner as the ONU 20 via any one of the OLTs 10. In this embodiment, as described above, it is assumed that the configuration change of each device configuring the optical communication network system 1 is possible from the control terminal 70. However, the configuration change of each device in the optical communication network system 1 is performed. The means to perform is not limited to this. For example, a maintenance terminal may be directly connected to each device (for example, connected via a console cable or the like) to change the setting, or a direct operation on each device (for example, an operation using a push button) ), The configuration can be changed.

  Next, details of each device constituting the optical communication network system 1 will be described.

  Next, details of the optical signal relay device 30 will be described.

  In this embodiment, the optical signal repeater 30 will be described as a configuration capable of connecting N PON branches 50 and N OLTs 10, but the PON branch 50 to which the optical signal repeater 30 is connected and The number of OLTs 10 is not limited.

  The optical signal repeater 30 includes an AWGR 31, which is an arrayed optical waveguide router (AWGR) configured by arranging optical wavelength filters, an electrical switch 32, and an OLT optical TR (transceiver) 33 corresponding to each OLT 10. (33-1 to 33-N) and ONU light TR34 (34-1 to 34-N) corresponding to the respective PON branches 50.

  The AWGR 31 is an optical wavelength router (optical wavelength routing means) configured by using an optical wavelength filter having circularity, and 2 * N communication ports (optical communication ports) capable of inputting and outputting optical signals. Optical left ports OLP1-2 * N (2 * N = N + M) and 2 * N optical right ports ORP1-2 * N (2 * N = M + N). It is assumed that a port number is assigned to each light left port OLP and each light right port ORP. In this embodiment, it is assumed that the port numbers of the optical left ports OLP1 to 2 * N are 1 to 2 * N, respectively. The port numbers of the right optical ports ORP1 to 2 * N are assumed to be 1 to 2 * N, respectively.

  The AWGR 31 is configured such that an optical signal input from any one of the optical left ports OLP is output from any one of the optical right ports ORP. The AWGR 31 is configured such that an optical signal input from any one of the optical right ports ORP is output from any one of the optical left ports OLP. The port number (one of 1 to 2 * N) of the port from which the optical signal input to the AWGR 31 is output is the port number (1 to 2 * N) of the input port and the wavelength of the input light. It depends on.

In AWGR31, a wavelength lambda as a reference, the wavelength separated by an integral multiple of lambda _FSR from _{λ λ + n * λ FSR (} n is nonzero integers) are treated as the same wavelength. This is called the circularity of the AWGR (array type optical waveguide router), and λ _FSR is called the free spectrum range. That is, the AWGR 31 is configured to output from the same optical communication port when light of two types of wavelengths satisfying this relationship is input from a certain optical communication port.

FIG. 2A shows the output port of the input optical signal based on the input port number (any one of 1 to N, N + 1 to 2 * N) of the input optical signal and the center wavelength of the input signal in the AWGR 31. It is the table shown about the rule from which a number is determined. In the AWGR 31, the center wavelength of the optical signal scheduled to be input is any one of λ _{1 to} λ _N and λ _{N + 1 to} λ _{2 * N.} The wavelength intervals of λ _{1 to} λ _{2 * N} are assumed to be Δλ. That is, it is assumed that λ ₂ = λ ₁ + Δλ, λ ₃ = λ ₂ + Δλ,... The wavelength intervals Δλ and λ _FSR corresponding to the AWGR 31 are specific values determined when the AWGR 31 is designed. In the AWGR 31 of this embodiment, it is assumed that the relationship 2 * N * Δλ = λ _FSR is established.

FIG. 2B shows an arrangement state of each wavelength shown in FIG. It is assumed that λ ₁ + λ _FSR = λ _{2 * N + 1} as shown in FIG.

  Next, the wiring connection relation of each port constituting the AWGR 31 will be described.

  The optical left ports OLP1 to NLP1 (first group optical communication ports) are connected to the OLTs 10-1 to 10-N via optical fibers (branch line optical transmission lines), respectively. The optical left ports OLPN + 1 to OLP2 * N (fourth group optical communication ports) are connected to the ONU optical TRs 34-1 to 34-N in the optical signal repeater 30. The optical right ports ORP1 to ORPN (second group optical communication ports) are connected to optical fibers (access optical transmission lines) constituting the PON branches 50-1 to 50-M, respectively. The optical right ports ORPN + 1 to ORP2 * N (third group optical communication ports) are connected to the OLT optical signals TR33-1 to 33-N, respectively.

  Each of the OLT light TR33 (33-1 to 33-N) and the ONU light TR34 (34-1 to 34-M) converts the input optical signal into an electric signal (binary digital signal). And a means for converting an input electrical signal into an optical signal.

  Next, the detailed configuration of the electrical switch 32 will be described.

  The electric switch 32 switches an electric signal, and has N electric left ports ELP1 to ELPN and N electric right ports ERP1 to ERPN. It is assumed that a port number is assigned to each electric port (electric left port ELP1 to ELPN, electric right port ERP1 to ERPN) constituting the electric switch 32. In this embodiment, the port numbers of the photoelectric left ports ELP1 to ELPN are 1 to N, respectively. The port numbers of the electric right ports ERP1 to ERPN are 1 to N, respectively.

  Each of the electric left port ELP and the electric right port ERP constituting the electric switch 32 is a port capable of inputting and outputting electric signals. That is, each electrical port has an output signal line for outputting an electrical signal from the electrical switch 32 and an input signal line for inputting an electrical signal to the electrical switch 32. The electrical switch 32 is configured such that an electrical signal input from one of the electrical left ports ELP is output from one or a plurality of electrical right ports ERP corresponding to the setting. The electrical switch 32 is configured such that an electrical signal input from any one of the electrical right ports ERP is output from one or a plurality of electrical left ports ELP according to the setting.

  That is, the electrical switch 32 has a function of outputting an electrical signal input from one electrical port to a plurality of electrical ports (multicast), and an electrical signal input from a plurality of electrical ports to one electrical port. It is assumed that it corresponds to the function (time multiplexing) that outputs all at once. Note that the switching path between the electrical ports in the electrical switch 32 can be arbitrarily changed according to control from the control terminal 70, for example.

  Each electrical port (electrical left port ELP1 to ELPN, electrical right port ERP1 to ERPN) of the electrical switch 32 is one of the transceivers (OLT light TR33-1 to 33-N, ONU light TR34-1 to 34). -M) is electrically connected to an electrical port (port for transmitting and receiving electrical signals).

  The electrical left ports ELP1 to ELPN are connected to the electrical ports of the ONU light TR34-1 to 34-M, respectively. The electrical right ports ERP1 to ERPN are connected to the OLT light TR33-1 to 33-N, respectively.

  Next, the internal configuration of each OLT 10 will be described.

  The OLT 10 can be substantially the same as that used in an existing access network (for example, EPON or GPON). However, the OLT 10 of this embodiment differs from the existing one in that the center wavelength of the optical signal transmitted and received on the GE-PON side is variable.

  FIG. 3 is a block diagram illustrating an example of a functional configuration of the OLT 10. In this embodiment, the OLTs 10-1 to 10-N will be described as having the same configuration.

  As described above, the OLT 10 is not limited to the configuration illustrated in FIG. 3 as long as the center wavelength of the optical signal transmitted and received on the GE-PON side can be made variable. In the OLT 10 of this embodiment, the center wavelength of the optical signal transmitted and received on the GE-PON side can be changed according to control from the control terminal 70 or the like.

  The OLT 10 illustrated in FIG. 3 includes a signal processing unit 11 and an optical transceiver 12.

  The optical transceiver 12 is an interface with the GE-PON side, and transmits and receives optical signals to and from the ONUs 20 constituting each PON branch 50 via the optical signal relay device 30. The optical transceiver 12 includes a TLD (Tunable Laser Diode) 121, a PD (Photo Diode) 122, and a WDM filter 123.

  The signal processing unit 11 processes data transmitted / received by the OLT 10, and has a control function for communication with the ONU 20.

The WDM filter 123 is connected to an optical fiber (branch line optical transmission line) to multiplex and demultiplex light having different wavelengths. In this embodiment, the WDM filter 123 has λ ₁ to λ _{2 * N} as the downstream signal wavelength and λ ₁ + n * λ _{FSR to} λ _{2 * n} + n * λ _FSR as the upstream signal wavelength (n is an integer other than zero) ) Shall be set. That is, in the OLT 10, light in different wavelength bands is assigned to the upstream signal and the downstream signal, so that the upstream optical signal and the downstream optical signal can be combined and demultiplexed by using the WDM filter 123.

The TLD 121 (variable wavelength optical transmitter) converts an electrical signal input from the signal processing unit 11 or the like into an optical signal, and transmits the optical signal to the GE-PON via the WDM filter 123. It is assumed that the TLD 121 can output light having a central wavelength of any one of λ ₁ to λ _{2 * N.}

  The PD 122 (optical receiver) converts an optical signal received via the WDM filter 123 into an electric signal and supplies the electric signal to the signal processing unit 11 and the like.

  Next, the internal configuration of each ONU 20 will be described.

  The ONU 20 can be substantially the same as that used in an existing access network (for example, GE-PON). However, the ONU 20 of this embodiment is different from the existing one in that the center wavelength of the optical signal transmitted and received on the GE-PON side is variable.

  FIG. 4 is a block diagram illustrating an example of a functional configuration of the ONU 20. In this embodiment, the ONU 20 will be described as having the same configuration.

  As described above, the ONU 20 is not limited to the configuration shown in FIG. 4 as long as the center wavelength of the optical signal transmitted and received on the GE-PON side can be made variable. In the ONU 20 of this embodiment, the center wavelength of the optical signal transmitted and received on the GE-PON side can be changed according to control from the control terminal 70 and the like.

  The ONU 20 illustrated in FIG. 4 includes a signal processing unit 21 and an optical transceiver 22.

  The optical transceiver 22 is an interface with the GE-PON side, and transmits and receives optical signals to and from the OLT 10 via the optical signal relay device 30. The optical transceiver 22 includes a TLD 221, a PD 222, and a WDM filter 223.

  The signal processing unit 21 processes data to be transmitted / received by the ONU 20 and has a control function for communication with the OLT 10.

  Similar to the WDM filter 123 of the OLT 10, the WDM filter 223 multiplexes and demultiplexes optical signals having different wavelengths between the upstream optical signal and the downstream optical signal.

The TLD 221 (variable wavelength optical transmitter) converts the electrical signal input from the signal processing unit 21 or the like into an optical signal, and transmits the optical signal to the GE-PON via the WDM filter 223. It is assumed that the TLD 221 can output light having a wavelength with a center wavelength of λ ₁ + n * λ _{FSR to} λ _{2 * n} + n * λ _FSR (where n is an integer other than zero).

  The PD 222 (optical receiver) converts an optical signal received via the WDM filter 223 into an electric signal and supplies it to the signal processing unit 21 and the like.

(A-2) Operation of the First Embodiment Next, the operation of the optical communication network system 1 of the first embodiment having the above configuration will be described.

  As described above, in the optical communication network system 1, each device (OLT 10, ONU 20, optical signal relay device 30) can be set from the control terminal 70, and a connection configuration (logical connection configuration) according to the setting of each device ) Is possible. Hereinafter, a plurality of examples will be described with respect to the setting configuration of each device constituting the optical communication network system 1.

  In the following description, in order to simplify the description, “N” representing the maximum number of OLTs 10 to be accommodated and “M” representing the maximum number of PON branches 50 to be accommodated in the optical signal repeater 30 are represented. , Both are set to “4”. In the following description, it is assumed that the above-described coefficient n for determining the wavelength arrangement of the upstream signal and downstream signal in GE-PON is set to “1”. Of course, these values are merely examples, and in practice, any value can be used. The contents of the routing table applied to the AWGR 31 when N = M = 4 and n = 1 are as shown in FIG.

(A-2-1) First Setting Configuration Example First, a first setting configuration example of the optical communication network system 1 will be described with reference to FIG. In FIG. 6, for simplicity of explanation, only devices related to the setting configuration example are illustrated, and other devices are omitted.

  In the first setting configuration example, only the OLT 10-1 is the setting target as the OLT 10. In the first setting configuration example, it is assumed that only four PON branches 50-1 to 50-4 are set as the PON branch 50.

  Next, a downlink signal transmitted from the OLT 10-1 in the first setting configuration example will be described.

In the first setting example configuration, the center wavelength of the downstream signal output from OLT10-1 is assumed to be set to lambda _5.

  Then, the optical signal output from the OLT 10-1 reaches the optical signal repeater 30 of the branch node station through the optical fiber (branch optical transmission line), and is input to the optical left port OLP1 (port number 1) of the AWGR31. Is done. Then, based on the routing table (see FIG. 5) of the AWGR 31, this downstream signal is output from the optical right port ORP5 of the AWGR 31, and converted into an electrical signal by the OLT optical TR 33-1. The downstream signal converted into the electrical signal is input to the electrical right port ERP1 of the electrical switch 32.

  Here, it is assumed that the electrical switch 32 is set to a route that multicasts the downstream electrical signal input from the electrical right port ERP1 to the electrical left ports ELP1 to ELP4. Then, the downstream electrical signal is input to the ONU optical signals TR34-1 to 34-4, converted into an optical signal having a wavelength corresponding to the setting, and the converted downstream optical signal is input to the AWGR31.

Here, the downstream optical signals output from the ONU optical signals TR34-1 to 34-4 are respectively input to the optical left ports OLP5 to OLP8 of the AWGR31 and output from the optical right ports ORP1 to ORP4 of the AWGR31. It shall be comprised as follows. That is, based on the routing table of FIG. 5 described above, the central wavelength of the downstream optical signal outputted from the ONU for optical TR34-1~34-4 each _{λ 5, λ 7, λ 1} , is set to lambda ₃ Need to be.

  The downstream optical signals output from the optical right ports ORP1 to ORP4 of the AWGR 31 constitute the PON branch 50 through the optical fibers (access optical transmission lines) of the connected PON branches 50-1 to 50-4, respectively. The ONU 20 (ONU group) is reached.

  Next, in the first setting configuration example, an upstream signal transmitted from the ONU 20 (ONU group) configuring each PON branch 50 will be described.

Here, the PON branches 50-1 to 50-4 are respectively connected to the optical right ports ORP1 to ORP4 of the AWGR31. Here, it is assumed that the upstream optical signals input to the optical right ports ORP1 to ORP4 of the AWGR 31 are output from the optical left ports OLP5 to OLP8, respectively. That is, here, in the PON branches 50-1 to 50-4, the center wavelengths of the upstream optical signals need to be set to λ ₁₃ , λ ₁₅ , λ ₉ , and λ ₁₁ , respectively.

  The upstream optical signals output from the optical left ports OLP5 to OLP8 are respectively input to the ONU optical signals TR34-1 to 34-4 and converted into electrical signals. The upstream electrical signals output from the ONU optical signals TR34-1 to 34-4 are input to the electrical left ports ELP1 to ELP4, respectively.

  In the electrical switch 32, switching is set so that all the upstream electrical signals input to the electrical left ports ELP1 to ELP4 are output from the electrical right port ERP1. That is, these four upstream electrical signals are multiplexed in time at the electrical right port ERP1. The timings of these four upstream signals (burst signals) are adjusted by the OLT 10-1 so that the burst signals do not overlap on the time axis (for example, controlled by MPCP control). Therefore, the electrical switch 32 does not need to perform delay adjustment or the like for the upstream electrical signal.

  The upstream electrical signal output from the electrical right port ERP1 (upstream electrical signal multiplexed in time) is input to the ONU optical TR 34-1 and converted into an optical signal.

  The upstream optical signal output from the ONU optical TR 34-1 is input to the optical right port ORP5 of the AWGR31.

Here, it is assumed that the upstream optical signal input to the optical right port ORP5 is output from the optical left port OLP1. That is, the central wavelength of the uplink optical signal output from the ONU for optical TR34-1 must be set to lambda _13.

  The upstream optical signal output from the optical left port OLP1 reaches the OLT 10-1 through an optical fiber (branch line optical transmission line).

  As described above, in the optical communication network system 1, both the upstream and downstream signals are once converted into electrical signals by the optical signal relay device 30 (branch node station) and then converted back to optical signals (hereinafter referred to as “regenerative relay”). Is called). That is, in the optical communication network system 1, since the optical signal attenuated by the transmission is regeneratively relayed, the loss budget can be expanded, and the transmission path can be increased in distance and multi-branched.

(A-2-2) Second Setting Configuration Example Next, a second setting configuration example of the optical communication network system 1 will be described with reference to FIG. In FIG. 7, only the devices related to the setting configuration example are illustrated and other devices are omitted for the sake of simplicity.

  In the second setting configuration example, only two OLTs 10-1 and 10-2 are set as the OLT 10. In the second setting configuration example, it is assumed that only four PON branches 50-1 to 50-4 are set as the PON branch 50. In the second setting configuration example, only the PON branch 50-1 is accommodated under the OLT 10-1, and the PON branches 50-2 to 50-4 are accommodated under the OLT 10-2. .

  Next, downlink signals transmitted from the OLTs 10-1 and 10-2 in the second setting configuration example will be described.

  Downstream optical signals output from the OLTs 10-1 and 10-2 are respectively input to the optical left ports OLP1 and OLP2 of the AWGR 31 via optical fibers (branch line optical communication paths) and output from the optical right ports ORP5 and ORP6. It shall be comprised so that.

That is, the center wavelengths of the downstream optical signals output from the OLTs 10-1 and 10-2 need to be set to λ ₅ and λ ₇ , respectively.

  The downstream optical signals output from the optical right ports ORP5 and ORP6 are input to the OLT optical signals TR33-1 and 33-2, respectively, and converted into electrical signals. Then, the electrical downlink signals output from the OLT light TR33-1 and 33-2 are input to the electrical right ports ERP1 and ERP2, respectively.

  In the electrical switch 32, it is assumed that the switching setting is performed so that the downstream electrical signal input to the electrical right port ERP1 is output from the electrical left port ELP1. Then, the downstream electrical signal output from the electrical left port ELP1 is converted into an optical signal by the ONU optical TR 34-1 as in the case of the first setting configuration example, and is transmitted via the AWGR31 (optical right port ORP1). The ONU 20 (ONU group) constituting the PON branch 50-1 is reached through the optical fiber (access optical transmission line) of the PON branch 50-1.

  On the other hand, in the electrical switch 32, it is assumed that the downstream electrical signal input to the electrical right port ERP2 is set to a route that is multicast to the electrical right ports ERP2 to ERP4. The downstream electrical signals output from the electrical left ports ELP2 to ELP3 are converted into optical signals by the ONU light TRs 34-2 to 34-4, as in the case of the first setting configuration example, and AWGR31 (optical right Via the ports ORP2 to ORP4), the optical fibers (access optical transmission lines) of the PON branches 50-2 to 50-4 are reached to the ONUs 20 (ONU group) constituting each PON branch 50.

  Next, in the second setting configuration example, an upstream signal transmitted from the ONU 20 (ONU group) configuring each PON branch 50 will be described.

  The upstream optical signals transmitted from the PON branches 50-1 to 50-4 are transmitted through the optical fibers (access optical transmission lines) of the PON branches 50-1 to 50-4, respectively, as in the first setting configuration example. The signals are input to the right ports ORP1 to ORP4, output from the optical left ports OLP5 to OLP8, input to the ONU optical signals TR34-1 to 34-4, and converted into electrical signals. The upstream electrical signals output from the ONU optical signals TR34-1 to 34-4 are input to the electrical left ports ELP1 to ELP4, respectively.

In the electrical switch 32, switching is set so that the upstream electrical signal input to the electrical left port ELP1 is output from the electrical right port ERP1. Here, the upstream electrical signal output from the electrical right port ERP1 is converted into an optical signal by the OLT light TR33-1 and input to the optical right port ORP5 and output from the optical left port OLP1. It shall be configured. Ie, the center wavelength of the upstream optical signal output from the ONU for optical TR34-1 must be set to lambda _13.

On the other hand, in the electrical switch 32, it is assumed that switching is set so that all the upstream electrical signals input to the electrical left ports ELP2 to ELP4 are output from the electrical right port ERP2. Here, the upstream electrical signal output from the electrical right port ERP2 is converted into an optical signal by the OLT light TR33-2, input to the optical right port ORP6, and output from the optical left port OLP2. It shall be configured. Ie, the center wavelength of the upstream optical signal output from the ONU for optical TR34-2 must be set to lambda _15.

  As described above, in the second setting configuration example, the number of OLTs 10 to be applied is increased from one to two for the four PON branches 50, so the communication band of the PON is (first setting configuration example). It is doubled. In other words, the PON communication band can be increased simply by adding the OLT 10 to the trunk node station. Further, it is obvious that the OLT 10 of the accommodation destination of each PON branch 50 can be easily changed by changing the setting of the optical signal relay device 30. Therefore, in the optical communication network system 1, by adding the OLT 10, it is possible to easily increase / decrease the communication band of the GE-PON, and to make an optimal capital investment at any time according to a change in demand of the communication band.

  Also, in the optical communication network system 1, since it is possible to flexibly determine which PON branch 50 (ONU group) each OLT 10 communicates with, communication quality can be set for each PON branch 50 (ONU group).

(A-2-3) Third Setting Configuration Example Next, a third setting configuration example of the optical communication network system 1 will be described with reference to FIG. In FIG. 8, for simplicity of explanation, only the devices related to the setting configuration example are illustrated, and the other devices are omitted.

  In the third setting configuration example, similar to the second setting configuration example, only two OLTs 10-1 and 10-2 and four PON branches 50-1 to 50-4 are set. And In the third setting configuration example, as in the second setting configuration example, only the PON branch 50-1 is accommodated under the OLT 10-1, and the PON branches 50-2 to 50-4 are under the OLT 10-2. Shall be contained.

  In the third setting configuration example, only the setting configuration under the OLT 10-1 (PON branch 50-1) is different from the second setting configuration example. Specifically, in the third setting configuration example, the optical signal between the OLT 10-1 and the PON branch 50-1 is transferred as the optical signal without relaying the electrical switch 32 in the optical signal relay device 30. (Hereinafter referred to as “light cut-through”). Accordingly, in the third setting configuration example, the settings of the subordinates of the OLT 10-2 (PON branches 50-2 to 50-4) are the same as those in the second setting configuration example, and thus description thereof is omitted.

  Next, a downstream signal transmitted from the OLT 10-1 in the third setting configuration example will be described.

The downstream optical signal output from the OLT 10-1 is input to the optical left port OLP1 of the AWGR 31 via the optical fiber (branch line optical communication path). In the third setting configuration example, it is assumed that the optical downstream signal input from the optical left port OLP1 has an optical cut-through configuration that is output from the optical right port ORP1 as it is. Specifically, by setting the central wavelength of the downstream optical signal outputted from the OLT10-1 to lambda _1, the light downstream signal input from the optical left port OLP1 is output as it is from the light right port ORP1 become. The downstream optical signal output from the optical right port ORP1 reaches the ONU 20 (ONU group) constituting the PON branch 50-1 through the optical fiber (access optical transmission line) of the PON branch 50-1.

  Next, in the third setting configuration example, an upstream signal transmitted from the ONU 20 (ONU group) configuring the PON branch 50-1 will be described.

The upstream optical signal output from the ONU 20 (ONU group) constituting the PON branch 50-1 is input to the optical right port ORP1 through the optical fiber (access optical transmission line). In the third setting configuration example, it is assumed that the optical upstream signal input from the optical right port ORP1 has an optical cut-through configuration that is output from the optical left port OLP1 as it is. Specifically, by setting the central wavelength of the uplink optical signal output from each ONU20 constituting the PON branches 50-1 to lambda _9, the optical downlink signal input from the optical right port ORP1 is directly light left It is output from the port OLP1.

  The upstream optical signal output from the optical left port OLP1 reaches the OLT 10-1 through an optical fiber (branch line optical transmission line).

  As described above, in the optical communication network system 1, it is not necessary to perform regenerative relay processing in the optical signal relay device 30 for the optical signal for the PON branch 50 with a small loss (attenuation or dispersion of the optical signal). By setting to perform through, the number of signals processed in the optical signal relay device 30 can be reduced, and effects such as reduction in power consumption can be achieved.

(A-2-4) Fourth Setting Configuration Example In the fourth setting configuration example, a description will be given of a process for recovering a failure by changing the setting of each device when a failure occurs in the optical communication network system 1. In the following, as an example, in the setting state of the third setting configuration example described above (the state shown in FIG. 7 above), a process for performing failure recovery by changing the setting depending on the location where the failure has occurred Will be described for each failure location.

[When a failure occurs in OLT10 or branch line optical communication path]
First, when a failure occurs in the optical fiber (branch line optical communication path) connecting the OLT 10-2 or OLT 10-2 and the optical signal repeater 30 (branch node station) in the setting state of the third setting configuration example described above. Will be described. In this case, as it is, the ONUs 20 (ONU group) of the PON branches 50-2 to 50-4 are in a state incapable of communicating with the upper side. However, the failure recovery can be performed by accommodating the PON branches 50-2 to 50-4 in the OLT 10-1 by changing the setting of each device. That is, the failure recovery can be performed by changing each device constituting the optical communication network system 1 to the same setting as in the first setting configuration example described above. Hereinafter, the details of the process of performing failure recovery separately for upstream signals and downstream signals will be described.

  First, it is detected that a failure has occurred in the optical fiber (branch line optical communication path) connecting the OLT 10-2 or OLT 10-2 and the optical signal repeater 30 (branch node station) (for example, by a GE-PON monitoring device) Detected).

First, it is assumed that a setting change is performed for each device of the optical communication network system 1 to recover the downlink signal. Specifically, first, it is necessary to switch the center wavelength of the downstream optical signal outputted from the OLT10-1 the lambda _5. By doing so, the downstream signal of the OLT 10-1 is output from the optical left port OLP1 to the optical right port ORP5, and is switched to a path that is input to the OLT optical TR 33-1. In addition, as with the first setting configuration example, the setting of the electrical switch 32 is changed so that the downstream electrical signal input to the electrical right port ERP1 is multicast to all the electrical left ports ELP1 to ELP4. There is a need. As described above, by changing the settings of each device of the optical communication network system 1 to the same setting as in the first setting configuration example, the downlink signal transmitted from the OLT 10-1 is transmitted to the PON branches 50-1 to 50-. 4 to reach all the ONUs 20.

Then, it is assumed that a setting change for performing recovery related to the uplink signal is performed for each device of the optical communication network system 1. Specifically, first, the central wavelength of the uplink optical signal ONU20 constituting the PON branches 50-1 sends out, it is necessary to set changes to all lambda _13. As a result, the upstream optical signal input from the PON branch 50-1 to the optical right port ORP1 is output from the optical left port OLP5. Similarly to the first setting configuration example, it is necessary to change the setting of the electrical switch 32 so that all the downstream electrical signals input to the electrical left ports ELP1 to ELP4 are output from the electrical right port ERP1. . As described above, the upstream signals transmitted from the ONUs 20 of the PON branches 50-1 to 50-4 are changed by changing the setting of each device of the optical communication network system 1 to the same setting as in the first setting configuration example. All will reach OLT 10-1.

  When a failure occurs in the optical fiber (branch line optical communication path) connecting the OLT 10 or the OLT 10 and the optical signal repeater 30 (branch node station) in the setting state of the third setting configuration example described above, Communication related to all ONUs 20 is restored by a simple setting change.

[When a failure occurs in the OLT optical TR33 of the optical signal repeater 30]
Next, a case where a failure occurs in the OLT optical TR 33-2 configuring the optical signal repeater 30 in the setting state of the third setting configuration example described above will be described. In this case, as it is, the ONUs 20 (ONU group) of the PON branches 50-2 to 50-4 are in a state incapable of communicating with the upper side. In such a case, the OLT 10-2 can be recovered by using another unused OLT light TR33 instead of connecting to the OLT light TR33-2. For example, here, it is assumed that the unused OLT light TR33-1 is connected to the OLT 10-2. Hereinafter, the details of the process of performing failure recovery separately for upstream signals and downstream signals will be described.

  First, it is assumed that a failure has occurred in the OLT optical TR 33-2 constituting the optical signal relay device 30 (for example, detected by a GE-PON monitoring device or the like).

First, it is assumed that a setting change is performed for each device of the optical communication network system 1 to recover the downlink signal. Specifically, it is assumed that switching between the center wavelength of the downstream signal output by the OLT10-2 the lambda _6. By doing so, the downlink signal of the OLT 10-2 is switched to a path that reaches the OLT optical TR 33-1 in the branch node station. In addition, it is necessary to change the setting of the electrical switch 32 so that the electrical signal input from the OLT light TR33-1 to the electrical right port ERP1 is multicast to the electrical left ports ELP2 to ELP4. As described above, the downlink signal transmitted from the OLT 10-2 reaches all the ONUs 20 in the PON branches 50-2 to 50-4 by changing the setting to each device of the optical communication network system 1. become.

Then, it is assumed that a setting change for performing recovery related to the uplink signal is performed for each device of the optical communication network system 1. It is not necessary to change the settings for the ONUs 20 of the PON branches 50-2 to 50-4. The upstream signals from the PON branches 50-2 to 50-4 are input to the electrical left ports ELP2 to ELP4 via the optical right ports ORP2 to ORP4 and the optical left ports OLP6 to OLP8. Therefore, it is necessary to change the setting of the electrical switch 32 so that all the upstream electrical signals input from the electrical left ports ELP2 to ELP4 are output from the electrical right port ERP-1. The upstream electrical signal output from the electrical right port ERP-1 is input to the OLT optical TR 33-1 to be converted into an optical signal, and input to the optical right port ORP5. In this case, the upstream optical signal input to the optical right port ORP5 needs to be output from the optical left port OLP2 and reach the OLT 10-2. Therefore, it is necessary to set the central wavelength of the uplink optical signal output by the OLT for an optical TR33-1 the lambda _14. As described above, by changing each device of the optical communication network system 1, all the upstream signals transmitted from the ONUs 20 of the PON branches 50-2 to 50-4 reach the OLT 10-2.

  If a failure occurs in the OLT optical TR 33 constituting the optical signal repeater 30 in the setting state of the third setting configuration example described above, communication related to all ONUs 20 is restored by, for example, the setting change as described above. To do.

[When a failure occurs in the ONU optical TR 34 of the optical signal repeater 30]
Next, a case where a failure has occurred in the ONU optical TR 34 constituting the optical signal repeater 30 in the setting state of the third setting configuration example described above will be described. Hereinafter, a case where a failure has occurred in the ONU light TR34-2 will be described. In this case, as it is, the ONU 20 (ONU group) of the PON branch 50-2 is in a state incapable of communicating with the host side. In such a case, the PON branch 50-2 can be restored by using another unused OLT optical TR33 instead of connecting to the ONU optical TR34-2. For example, here, it is assumed that the unused ONU optical TR 34-1 is connected to the PON branch 50-2. Hereinafter, the details of the process of performing failure recovery separately for upstream signals and downstream signals will be described.

  First, it is assumed that a failure has occurred in the ONU optical TR 34-2 constituting the optical signal relay device 30 (for example, detected by a GE-PON monitoring device or the like).

First, it is assumed that a setting change is performed for each device of the optical communication network system 1 to recover the downlink signal. Here, the center wavelength of the downstream optical signal output from the OLT 10-2 is not changed, and is input to the OLT light TR33-2 via the optical left port OLP2 and the optical right port ORP6. For the electrical switch 32, the setting is changed so that the electrical signal input from the OLT light TR33-2 to the electrical right port ERP2 is multicast to the electrical left ports ELP1, ELP3, ELP4 (before the electrical left port (Multicast to ELP2 to ELP4) is required. Then, the electrical downstream signals output from the electrical left ports ELP1, ELP3, and ELP4 are input to the ONU light TRs 34-1, 34-3, and 34-4, respectively. Note that the downstream electrical signals input to the ONU optical signals TR34-3 and 34-4 are not particularly troublesome and will not be described, and will not be described. The downstream electrical signal input to the ONU optical TR 34-1 is converted to an optical signal and input to the optical left port OLP5. Here, the optical downstream signal input to the optical left port OLP5 needs to be output from the optical right port ORP2 and reach the PON branch 50-2. Accordingly, the central wavelength of the optical downlink signal output from the ONU for optical TR34-1 must be set change lambda _6. As described above, by changing the setting of each device of the optical communication network system 1, the downstream signal transmitted from the OLT 10-2 reaches the ONU 20 of the PON branch 50-2.

Next, it is assumed that a setting change is performed for each device of the optical communication network system 1 to recover the uplink signal. Here, the upstream optical signal output from the ONU 20 of the PON branch 50-2 needs to be input to the optical right port ORP2 and output from the optical left port OLP5. Therefore, the center wavelength of the optical upstream signal output from ONU20 PON branch 50-2, it is necessary to set change lambda _14. By doing so, the upstream signal output from the ONU 20 of the PON branch 50-2 is input to the ONU light TR34-1, converted into an electrical signal, and input to the electrical left port ELP1. For the electrical switch 32, it is necessary to change the setting so that the upstream electrical signals input to the electrical left ports ELP1, ELP3, and ELP4 are output from the electrical right port ERP2. As described above, by changing each device of the optical communication network system 1, the upstream signal transmitted from the PON branch 50-2 reaches the OLT 10-2.

  If a failure occurs in the ONU optical TR 34 constituting the optical signal repeater 30 in the setting state of the third setting configuration example described above, communication related to all ONUs 20 is restored by, for example, the above setting change. To do.

  As described above, in the optical communication network system 1, even when a failure occurs in each part of the network of the OLT 10 or lower, communication is restored using a route that bypasses the failure point by simply changing the setting of each device. be able to.

(A-3) Effects of First Embodiment According to the first embodiment, the following effects can be achieved.

  As described above, in the optical communication network system 1 according to the first embodiment, the loss budget of the GE-PON can be expanded, and the GE-PON can be increased in distance and multi-branched.

  In the optical communication network system 1, for example, by setting each device as in the second setting configuration example, the communication band of the GE-PON can be increased according to demand.

  In the optical communication network system 1, for example, when each device is set as in the third setting configuration example, the optical cut-through operation or the regenerative repeat operation can be selected for each PON branch 50. Effects such as reduction of power consumption in the device 30 can be achieved.

  Furthermore, in the optical communication network system 1, for example, when a communication failure occurs as in the fourth setting configuration example, it is possible to easily recover using a route that bypasses the failure location by simply changing the setting of each device. Can do.

(B) Second Embodiment Hereinafter, a second embodiment of the optical signal relay device and the optical communication network system according to the present invention will be described in detail with reference to the drawings.

  FIG. 9 is a block diagram showing the overall configuration of the optical communication network system 1A of the second embodiment, and the same or corresponding parts as those in FIG. 1 are given the same or corresponding reference numerals.

  Hereinafter, only the difference between the second embodiment and the first embodiment will be described.

  In the optical communication network system 1A, four OLTs 10-1 to 10-4 are installed in the trunk node station.

  The OLTs 10-1 to 10-4 are the same as the first embodiment in that they are respectively connected to the optical left ports OLP1 to OLP4 of the AWGR 31, but in the second embodiment, as shown in FIG. Optical multiplexer / demultiplexers 80 and 90 are inserted between the OLTs 10-1 to 10-4 and the AWGR31.

  The optical multiplexer / demultiplexer 80 is installed in the trunk node station and is connected to the OLTs 10-1 to 10-4. On the other hand, the optical multiplexer / demultiplexer 90 is connected to the optical left ports OLP1 to OLP4 of the AWGR31. The optical multiplexer / demultiplexer 80 and the optical multiplexer / demultiplexer 90 are connected by a single optical fiber (branch line optical transmission line). That is, in the first embodiment, it is necessary to secure an optical fiber (branch line optical transmission line) for connecting to the optical signal repeater 30 (branch node station) for the number of OLTs 10, but the second embodiment. Then, by inserting the optical multiplexers / demultiplexers 80 and 90, the number of necessary optical fibers (branch line optical transmission lines) is reduced.

  The optical multiplexer / demultiplexer 80 includes four master station side optical ports 81-1 to 81-4 for connection to the four OLTs 10-1 to 10-4, and the optical signal repeater 30 (branch node station). A transmission path side optical port 82 for connecting to the side optical fiber (line-of-sight optical transmission path). It is assumed that 1 to 4 are assigned as the port numbers of the master station side optical ports 81-1 to 81-4, respectively.

  In addition, the optical multiplexer / demultiplexer 90 is also connected to the four optical left ports OLP1 to OLP4 of the AWGR 31 with four relay device side optical ports 91-1 to 91-4 and the trunk node station side (optical signal relay device 30). A transmission line side optical port 92 for connection to the transmission line. It is assumed that 1 to 4 are assigned as the port numbers of the relay apparatus side optical ports 91-1 to 91-4, respectively.

  Although the characteristics of the optical multiplexers / demultiplexers 80 and 90 are not limited, it is assumed in this embodiment that an optical wavelength filter having circularity in transmission characteristics is applied as in the AWGR 31.

  In the optical multiplexer / demultiplexers 80 and 90 of this embodiment, the corresponding wavelength interval (Δλ) between the optical ports (master station side optical port 81 or repeater side optical port 91) having adjacent port numbers is the same as that of the AWGR 31. Suppose that

In this embodiment, for example, the center wavelength between the master station side optical port 81-1 and the repeater side optical port 91-1 of the optical multiplexer / demultiplexer 80 is λ _{1 + 4 * m} (ie, λ ₁ , λ ₅ , Λ ₉ , λ ₁₃ ) only optical signals can pass. Further, for example, the center wavelength is λ _{2 + 4 * m} (ie, λ ₂ , λ ₆ , λ ₁₀₎ between the master station side optical port 81-1 and the repeater side optical port 91-1 of the optical multiplexer / demultiplexer 80. , Λ ₁₄ ) can pass only the optical signal. That is, in the optical multiplexer / demultiplexers 80 and 90, it can be said that the free spectrum range is set to one half of the free spectrum range (λ _FSR ) of the AWGR 31.

  As described above, insertion of the optical multiplexers / demultiplexers 80 and 90 imposes restrictions on the wavelengths used for the input / output signals of the OLT 10, but even under such restrictions, the optical signal repeater 30 (branch node station) The advantage that the selection of optical cut-through or regenerative relay can be selected according to the transmission wavelength of the OLT 10 is not lost. The reason will be described below.

As described above, the center wavelengths of optical signals that can be used for transmission / reception in the OLT 10-1 are only wavelengths λ ₁ , λ ₅ , λ ₉ , and λ ₁₃ . In the OLT 10-1, the wavelengths that can be used for the transmission of the downstream optical signal are λ ₁ and λ ₅ among these in terms of the routing setting of the AWGR 31. When λ ₁ is selected as the downstream optical signal output from the OLT 10-1, the AWGR 31 performs an optical cut-through operation in which the downstream optical signal input from the optical left port OLP1 is output to the optical right port ORP1 as it is. On the other hand, when λ ₅ is selected as the downstream optical signal output from the OLT 10-1, the downstream optical signal input from the optical left port OLP1 is output to the optical right port ORP5 and the regenerative relay operation is performed in the AWGR31. Similarly, for the upstream signal to the OLT 10-1, when λ ₉ is input to the optical right port ORP1, the optical cut-through operation is output to the optical left port OLP1 as it is, and λ ₁₃ is input to the optical right port ORP1. If it is input, it is output to the optical left port OLP5 and a regenerative relay operation is performed.

  Thus, in this embodiment, in each OLT 10, the wavelength that can be used for each of the upstream optical signal and downstream optical signal is limited to two types, one of which is an optical cut-through operation, and the other is the reproduction. Relay operation is performed. Therefore, in this embodiment, in each OLT 10, it is possible to switch between cut-through operation and regenerative relay operation by selecting an output wavelength from two wavelengths. Since the same can be said for the other OLTs 10-2 to 10-4, description thereof is omitted.

As described above, by setting the free spectrum range to one half of the free spectrum range (λ _FSR ) of the AWGR 31 in the optical multiplexer / demultiplexers 80 and 90, even in an environment where the optical multiplexer / demultiplexers 80 and 90 are inserted. Communication between each OLT 10 and each PON branch 50 (each ONU 20) becomes possible.

(C) Other Embodiments The present invention is not limited to the above-described embodiments, and may include modified embodiments as exemplified below.

(C-1) In each of the above embodiments, it has been described that each device configuring the optical communication network system 1 has a configuration using the technology of GE-PON (IEEE802.3ah). You may make it build using the technique of.

(C-2) In each of the above-described embodiments, the optical signal relay device is described as one device, but the method of dividing each component is not limited. For example, each component of the optical signal relay device may be configured by a separate casing (chassis), or may be configured by using a casing (chassis) that summarizes some or all of the functions of the components. You may make it do.

(C-3) In each of the above-described embodiments, the optical wavelength routing means configuring the optical signal repeater is configured using one AWGR, but the specific configuration for realizing the optical wavelength routing means is limited. For example, a plurality of optical wavelength routers, AWGR, etc. may be combined.

  Further, in each of the above embodiments, the electric signal exchanging means constituting the optical signal relay device is configured using one electric switch, but the specific configuration for realizing the electric signal exchanging means is not limited. For example, a plurality of electrical switches or the like may be combined.

  DESCRIPTION OF SYMBOLS 1 ... Optical communication network system, 30 ... Optical signal repeater, 20 ... ONU, 21 ... Signal processing part, 22 ... Optical transceiver, 221 ... TLD, 222 ... PD, 223 ... WDM filter, 10 ... OLT, 11 ... Signal processing , 12 ... optical transceiver, 121 ... TLD, 122 ... PD, 123 ... WDM filter, 10-1 to 10-N ... OLT, 40 ... optical splitter, 50, 50-1 to 50-N ... PON branch, 60 ... Core transmission device, 70 ... control terminal, 31 ... AWGR, OLP, OLP1-OLPN ... left optical port, ORP, ORP1-ORP4 ... right optical port, 32 ... electric switch, ELP, ELP1-ELPN ... electric left port, ERP , ERP1 to ERPN ... Electric right port, 33, 33-1 to 33-N ... Optical TR for OLT, 34, 34-1 to 34-M ... NU light TR.

Claims (10)

Between one or a plurality of master station communication devices and one or a plurality of optical access networks having a branched optical transmission line and one or a plurality of slave station communication devices connected to a branch destination of the optical transmission line In an optical signal repeater that relays an optical signal,
It has a plurality of optical communication ports for transmitting and receiving optical signals, and outputs an optical signal input to one of the optical communication ports from another optical communication port according to the wavelength of the optical signal, The optical communication port includes a first group including an optical communication port for connecting to each of the master station communication devices, and a second group including an optical communication port for connecting to an optical transmission line of each of the optical access networks. A third group including an optical communication port for transmitting / receiving an optical signal to / from the optical communication port of the first communication port group, and an optical signal to / from the optical communication port of the second group. Optical wavelength routing means divided into a fourth group including a plurality of optical communication ports;
Electrical signal exchange means for having a plurality of electrical communication ports for transmitting and receiving electrical signals, and outputting electrical signals input to any of the electrical communication ports from other electrical communication ports according to settings;
First signal conversion means for performing conversion processing between an electrical signal and an optical signal between each optical communication port belonging to the third group and the electrical communication port of the electrical signal exchange means;
Second signal conversion means for performing conversion processing between an electric signal and an optical signal between each optical communication port belonging to the fourth group and the electric communication port of the electric signal exchange means; An optical signal relay device comprising:   2. The optical signal repeater according to claim 1, wherein the optical wavelength routing means is configured using an optical wavelength router having a circular optical wavelength filter.   The first signal conversion unit and the second signal conversion unit can supply an optical signal having a wavelength corresponding to the setting for each optical communication port when the optical signal is supplied to the optical communication port. The optical signal repeater according to claim 1 or 2. One or a plurality of master station communication devices, one or a plurality of optical access networks each having a branched optical transmission line and one or a plurality of slave station communication devices connected to a branch destination of the optical transmission path; In an optical communication network system comprising an optical signal relay device that relays an optical signal between a station communication device and the optical access network,
An optical communication network system, wherein the optical signal repeater according to claim 1 is applied as the optical signal repeater.   The optical communication network system according to claim 4, wherein each of the master station communication devices outputs an optical signal having a wavelength corresponding to a setting.   6. The optical communication network system according to claim 4, wherein each of the slave station communication devices constituting each of the optical access networks outputs an optical signal having a wavelength corresponding to a setting. Each of the master station communication devices outputs an optical signal having a wavelength according to the setting,
Each of the slave station communication devices constituting each of the optical access networks outputs an optical signal having a wavelength corresponding to the setting,
A part or all of the master station communication device, so that the optical wavelength routing means directly routes between the first group of optical communication ports and the second group of optical communication ports; and 5. The optical communication network system according to claim 4, wherein a wavelength of an optical signal output from a slave station communication device belonging to a part or all of the access network is set.   A master station side optical multiplexer / demultiplexer for multiplexing / demultiplexing optical signals of optical transmission lines connected to the plurality of master station communication devices, and an optical communication port belonging to the first group of the plurality of optical wavelength routing means. A repeater side optical multiplexer / demultiplexer that multiplexes / demultiplexes the optical signals of the connected optical transmission lines, and the optical transmission line between the master station side optical multiplexer / demultiplexer and the repeater side optical multiplexer / demultiplexer The optical communication network system according to any one of claims 4 to 7, wherein the optical communication network system is connected by the above. The optical wavelength routing means is configured using an optical wavelength router having a circular optical wavelength filter,
The optical communication network system according to claim 8, wherein the master station side optical multiplexer / demultiplexer and the repeater side optical multiplexer / demultiplexer are configured using a circular optical wavelength filter. The free spectrum range of the optical wavelength filter constituting the master station side optical multiplexer / demultiplexer and the repeater side optical multiplexer / demultiplexer is half of the free spectrum range of the optical wavelength filter constituting the optical wavelength routing means. The optical communication network system according to claim 9.

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