JP5788844B2 - Optical communication system and optical communication method - Google Patents

Description

  The present invention relates to a technology related to dynamic path switching of a PON system having a concentrator at a higher level.

  High-speed access lines have become widespread by using a shared access method that realizes economy by sharing the line capacity among multiple users. FIG. 23 shows a typical access network configuration. In the optical section, concentration is performed by a passive optical network (PON) that accommodates a plurality of users in a single optical fiber using an optical passive element, and the plurality of PONs are electrically concentrated via a concentration switch. Connected to the upper network.

  Communication from the concentrator switch to the child node is generally referred to as “downlink communication”, and communication from the child node to the concentrator switch is generally referred to as “uplink communication”. Therefore, the same expression is used in this specification unless otherwise specified. We will use it. In the PON, a parent node in the figure corresponds to an in-station device (OSU: Optical Subscriber Unit), and a child node corresponds to a user premises device (ONU: Optical Network Unit). In PON, an optical splitter is inserted in the middle of an optical fiber network, and further, user division is performed using time division multiplexing (TDM) technology, so that a plurality of fiber lines and OSUs between the optical splitter and the OSU-optical splitter are provided. Shared by all subscribers. A plurality of PONs are bundled by a line concentrator switch, and further, user multiplexing is performed using TDM technology, so that the line between the line concentrator switch and the line concentrator switch and the upper network is shared (Non-patent Document 1). In FIG. 23, N users share the optical splitter, the fiber line between the OSU and the optical splitter, and the OSU. The line between the line concentrator switch and the line concentrator switch and the upper network is shared by N × M users.

  In the access network configuration of FIG. 23, the user group sharing one OSU is fixed and cannot be made variable, so the traffic volume differs between different OSUs.

Junichi Kani, “Enabling Technologies for Future Scalable and Flexible WDM-PON and WDM / TDM-PON Systems,” IEEE JSTQE, vol. 16, no. 5, pp. 1290-1297, 2010. Hirotaka Nakamura, Shinya Tamaki, Kazutaka Hara, Shunji Kimura, and Hisaya Hadama, “40 Gbit / s λ-tunable stacked-WDM / TDM-PON using”.

  With the spread of high-speed access services, various forms of applications and services have appeared on the Internet, and the usage methods of net users have also diversified. As a result of increased use not only for Web browsing but also for content distribution services such as music / video file download and streaming, voice communication using P2P applications, online games, file sharing and exchange, etc. It has been confirmed that there is a heavy user that generates a traffic volume 1000 times or more the average traffic volume.

  Therefore, in the current network configuration in which the user group sharing the parent node is fixed, a load difference occurs depending on the combination of users sharing the parent node. For example, when considering downlink communication, if the total traffic volume addressed to users accommodated in the same parent node does not exceed the line capacity between the concentrator switch and the parent node, the available bandwidth differs for each line, and Depending on the node, there is a difference in the maximum effective speed when requesting new traffic. Next, when the total traffic volume of users accommodated in the same parent node exceeds the line capacity between the line collecting switch and the parent node, a difference in delay or packet loss occurs depending on the accommodated parent node. Considering the case of uplink communication, if the transmission request of a user accommodated in the same parent node does not exceed the communication capacity of the parent node, the available bandwidth differs for each line, and a new transmission request depends on the accommodated parent node. There is a difference in the maximum effective speed when Next, when a transmission request of a user accommodated in the same parent node exceeds the capacity of the parent node, a difference in delay or packet loss occurs depending on the accommodated parent node.

  As described above, in the conventional PON system, the maximum effective speed / delay / packet loss variation caused by the load variation for each OSU according to the traffic characteristics of the accommodated users between the OSUs of the station side devices accommodating each user. was there. An object of the present invention is to solve such variations in maximum effective speed, delay, and packet loss between OSUs.

  In order to achieve the above object, the present invention has a traffic counter capable of measuring the traffic amount for each user in order to solve the variation in load for each OSU, so that the OSU under the dynamic path switching unit can be controlled. Traffic is distributed fairly and the unfairness of load between OSUs can be resolved.

Specifically, the optical communication system of the present invention is an optical communication system in which each child node can be accommodated in any parent node by connecting a parent node and a plurality of child nodes via an optical fiber transmission line. A counter that measures traffic for each child node over an arbitrary time, and an assignment circuit that assigns a parent node in which the child node is accommodated so that each parent node approaches an equal load according to the amount of traffic measured by the counter And a dynamic path switching unit that inputs traffic to the child node and outputs the traffic to the parent node allocated by the allocation circuit. Each parent node receives traffic received from the dynamic path switching unit. To the child node assigned from the assignment circuit, and each child node is assigned a parent node assigned from the assignment circuit. Is received by the change of the output port in the dynamic path switching unit, the change of the transmission wavelength selected by the parent node, and the change of the reception wavelength selected by the child node. This is characterized in that the parent node changes over time.
The allocation circuit counts the traffic passed in units of child nodes, rearranges them according to the traffic volume, and then allocates the parent nodes in order from the child nodes with the smaller traffic volume.

  In the optical communication system of the present invention, the optical fiber transmission line has each parent node and each child node connected via an optical splitter, and the parent node sends traffic received from the dynamic path switching unit to the parent node. The optical splitter branches and forwards the traffic transmitted by the parent node to each child node, and each child node transmits the parent node assigned by the assignment circuit. You may selectively receive traffic having the same wavelength as the transmission wavelength.

  In the optical communication system of the present invention, in the optical fiber transmission line, each parent node and each child node are connected via a common wavelength router, and the parent node receives the traffic received from the dynamic path switching unit, Transfer using the wavelength at which traffic arrives at the target child node after passing through the wavelength router, and the wavelength router transfers the traffic transmitted by the parent node to the output port uniquely determined from the input port and the signal wavelength. Each child node may receive an arriving signal.

  In the optical communication system of the present invention, the optical fiber transmission line has each parent node connected to a common wavelength router, each port of the wavelength router is connected to a plurality of child nodes via an optical splitter, and the parent node is The traffic received from the dynamic path switching unit is transferred using the wavelength at which the traffic arrives at the target child node after passing through the wavelength router, and the wavelength router transmits the traffic transmitted from the parent node to the input port. The traffic may be transferred to an output port that is uniquely determined from the wavelength of the signal, and the child node may receive traffic having the same wavelength as the transmission wavelength of the parent node assigned by the assignment circuit.

  In the optical communication system of the present invention, the optical fiber transmission line has each parent node connected to a common first optical splitter, and the first optical splitter is connected to a common wavelength router. The port is connected to a plurality of child nodes via an optical splitter, and the parent node transfers the traffic received from the dynamic path switching unit using the wavelength at which the traffic arrives at the target child node after passing through the wavelength router. The wavelength router transfers the traffic transmitted from the parent node to the output port uniquely determined from the input port and the wavelength of the signal, and the child node transmits the transmission wavelength of the parent node assigned by the assignment circuit. The same wavelength traffic may be received.

Specifically, the optical communication method of the present invention is an optical communication system in which each parent node can be accommodated in any parent node by connecting the parent node and a plurality of child nodes via an optical fiber transmission line. An optical communication method, wherein traffic is measured for each child node over an arbitrary time, and an allocation procedure for assigning a parent node accommodating the child node so that each parent node approaches an equal load according to the measured traffic volume, A dynamic path switching procedure for outputting the traffic of the child node to the parent node allocated in the allocation procedure, and each parent node allocated the traffic of the child node allocated in the allocation procedure from the allocation circuit Forward to the child node, and each child node receives traffic transmitted from the parent node assigned in the assignment procedure. In order to accommodate the child node by changing the output port in the dynamic path switching procedure, changing the transmission wavelength selected by the parent node, and changing the reception wavelength selected by the child node. The parent node to be changed changes with time.
In the allocation procedure, the traffic passed in units of child nodes is counted and rearranged according to the traffic volume, and then the parent nodes are allocated in order from the child node having the smaller traffic volume.

  In the optical communication method of the present invention, each of the optical fiber transmission line is connected to each parent node and each child node via an optical splitter. In the traffic transmission procedure, the parent node is a child assigned in the assignment procedure. The node traffic is transferred using a wavelength predetermined for each parent node, and the optical splitter branches and forwards the traffic transmitted by the parent node to each child node. Traffic having the same wavelength as the transmission wavelength of the parent node assigned in the procedure may be selectively received.

  In the optical communication method of the present invention, in the optical fiber transmission line, each parent node and each child node are connected via a common wavelength router, and in the traffic transmission procedure, the parent node transmits the dynamic path switching procedure. The traffic received by the node is transferred using the wavelength at which the traffic arrives at the target child node after passing through the wavelength router. The wavelength router uniquely transmits the traffic transmitted by the parent node from the input port and the signal wavelength. Each child node may receive the arriving signal, forwarding to the determined output port.

  In the optical communication method of the present invention, the optical fiber transmission line is configured such that each parent node is connected to a common wavelength router, and each port of the wavelength router is connected to a plurality of child nodes via an optical splitter. In the procedure, the parent node transfers the traffic received in the dynamic route switching procedure using the wavelength at which the traffic arrives at the target child node after passing through the wavelength router, and the wavelength router transmits the parent node. The traffic may be transferred to an output port that is uniquely determined from the input port and the wavelength of the signal, and each child node may receive traffic having the same wavelength as the transmission wavelength of the parent node assigned in the assignment procedure.

  In the optical communication method of the present invention, the optical fiber transmission line has each parent node connected to a common first optical splitter, and the first optical splitter is connected to a common wavelength router. A port is connected to a plurality of child nodes via an optical splitter, and in the traffic transmission procedure, the parent node receives the traffic received in the dynamic route switching procedure, and the traffic arrives at the target child node after passing through the wavelength router. The wavelength router transfers the traffic transmitted by the parent node to the output port uniquely determined from the input port and the wavelength of the signal, and the child node is assigned in the assignment procedure. Traffic having the same wavelength as the transmission wavelength of the parent node may be received.

  According to the present invention, the downlink signal and the uplink signal can be made closer to each other so that the load between the OSUs becomes uniform by changing the OSU accommodated in the ONU according to the load of the OSU. Further, according to the present invention, it is possible to switch to a redundant system in response to an OSU failure.

It is a block diagram which shows the structural example of the optical communication system in the 1st Embodiment of this invention. An example of the signal in the 1st Embodiment of this invention is shown. It is a block diagram which shows the structural example of the optical communication system in the 2nd Embodiment of this invention. An example of the signal in the 2nd Embodiment of this invention is shown. It is a block diagram which shows the structural example of the optical communication system in the 3rd Embodiment of this invention. It is a block diagram which shows the structural example of the optical communication system in the 4th Embodiment of this invention. It is a block diagram which shows the structural example of the optical communication system in the 5th Embodiment of this invention. An example of the signal in the 5th Embodiment of this invention is shown. An example of the wavelength routing function characteristic of circular AWG is shown. It is a block diagram which shows the structural example of the optical communication system in the 6th Embodiment of this invention. An example of the signal in the 6th Embodiment of this invention is shown. It is a block diagram which shows the structural example of the optical communication system in the 7th Embodiment of this invention. It is a block diagram which shows the structural example of the optical communication system in the 8th Embodiment of this invention. It is a block diagram which shows the structural example of the optical communication system in the 9th Embodiment of this invention. It is a block diagram which shows the 2nd structural example of the optical communication system in the 9th Embodiment of this invention. It is a block diagram which shows the structural example of the optical communication system in the 10th Embodiment of this invention. It is a block diagram which shows the structural example of the optical communication system in the 11th Embodiment of this invention. It is a block diagram which shows the structural example of the optical communication system in the 12th Embodiment of this invention. It is a block diagram which shows the structural example of the optical communication system in the 13th Embodiment of this invention. It is a block diagram which shows the structural example of the optical communication system in the 14th Embodiment of this invention. It is a block diagram which shows the structural example of the optical communication system in the 15th Embodiment of this invention. It is a block diagram which shows the structural example of the optical communication system in the 16th Embodiment of this invention. An example of the structure of an access network is shown.

  Embodiments of the present invention will be described with reference to the accompanying drawings. The embodiments described below are examples of the present invention, and the present invention is not limited to the following embodiments. In the present specification and drawings, the same reference numerals denote the same components.

  An optical communication system according to the present invention is an optical communication system in which each child node can be accommodated in any parent node by connecting the parent node and a plurality of child nodes via an optical fiber transmission line. And an allocation circuit and a dynamic path switching unit. The optical communication method according to the present invention includes an assignment procedure, a dynamic route switching procedure, and a traffic transmission procedure in this order.

In the assignment procedure, the counter measures traffic for each child node over an arbitrary time, and assigns a parent node in which the child node is accommodated so that each parent node approaches an equal load according to the traffic amount measured by the assignment circuit.
In the dynamic route switching procedure, the traffic of the child node is output to the parent node assigned in the assignment procedure.
In the traffic transmission procedure, each parent node forwards the traffic of the child node assigned in the assignment procedure to the child node assigned from the assignment circuit, and each child node is transmitted from the parent node assigned in the assignment procedure. Receive traffic.
Then, the parent node accommodated by the child node is temporally changed by changing the output port in the dynamic path switching procedure, changing the transmission wavelength selected by the parent node, and changing the reception wavelength selected by the child node. .

  By adopting these configurations, the present invention changes the OSU accommodated in the ONU according to the load of the OSU for the downlink signal and the uplink signal, thereby bringing the load between the OSUs closer to each other. Enable. Further, according to the present invention, it is possible to switch to a redundant system in response to a failure of the OSU 20.

(First embodiment)
FIG. 1 is a block diagram showing a configuration example of an optical communication system according to the first embodiment of the present invention. FIG. 2 shows an example of a signal according to the present embodiment, and a description is given below. From each OSU, TDM optical signal _{DL OSU # 1 ··· DL OSU #} K is output using the different wavelengths λ ₁ ··· λ _K. TDM optical signal output by the different wavelengths of the are multiplexed with the optical splitter _41, a WDM / TDM (Wavelength Division Multiplexing / Time Division Multiplexing) signal as _{D SP,} input to each ONU. Each at a wavelength variable filter 12 in the ONU _10, to transmit selected wavelengths signals allocated from the allocation circuit 50 as _{DL ONU # 1 ··· DL ONU #} K from the _{D SP.} The receiver 11 determines whether or not the received frame DL _{ONU # 1} ... DL _{ONU # K} is addressed to itself, and selects a received frame. In GE-PON, this determination is performed using an identifier called LLID (Logical Link ID), and it is compared with an individual LLID designated for each user. Otherwise, it is determined that it is not addressed to itself and the received frame is discarded.

  The load between a plurality of different OSUs 20 is controlled for downlink traffic, and the OSU 20 that accommodates downlink traffic and the OSU 20 that accommodates uplink traffic may be different or the same.

  The optical communication system of the present embodiment includes a dynamic path switching unit 30, an OSU 20, an optical splitter 41, and an ONU 10. The dynamic route switching unit 30 may be included in the same device as the OSU 20 or may be included in a higher-level device that is separated. One optical splitter 41 may be used as one stage, or a plurality of optical splitters 41 may be arranged in series to form a plurality of stages.

Different transmission wavelengths λ _n (n = 1, 2,..., K) are set in a plurality of different OSUs 20, and the signals are WDM / TDM. The OSU 20 transfers the traffic received from the dynamic path switching unit 30 using a wavelength that is predetermined for each OSU 20. The plurality of ONUs 10 are connected to the plurality of OSUs 20 via the optical splitter 41, and the optical splitter 41 branches the traffic transmitted by the OSU 20 to all the ONUs 10 and transfers them. Each ONU 10 is equipped with a wavelength tunable filter 12, and extracts from the WDM / TDM signal only the wavelength containing the own signal having the same wavelength as the transmission wavelength of the parent node assigned by the assignment circuit 50. Take out only its own signal.

  The output port of a certain user signal is changed by the dynamic route switching unit 30. It is branched by the optical splitter 41, the reception wavelength is changed by the ONU 10, and the OSU 20 accommodated is changed by changing the connection between the OSU 20 and the ONU 10.

  The wavelength tunable filter 12 is, for example, an electric type using a diffraction grating as a low-speed filter, and a semiconductor optical amplifier (SOA) arranged in parallel between two AWGs as a high-speed filter as a gate element (non- Patent Document 2) is conceivable.

  Further, the reception wavelength may be selected by using the coherent receiver 11 using the wavelength tunable local light source instead of the wavelength tunable filter 12 in the ONU 10. On the other hand, in the coherent reception, since the interference component between the signal light and the local light is extracted as the signal component, the signal light and the local light are emitted so that the frequency of the interference component between the signal light and the local light is within the electrical band of the receiver 11. It is necessary to stabilize the wavelength of the light with high accuracy. As a technique for obtaining high-accuracy wavelength stability of local light for high-speed wavelength switching, one of the output lights from a plurality of light sources that continuously emit light at different wavelengths arranged in an array is used with an optical switch. A configuration in which the wavelength is selected, a configuration in which one of the wavelength components of the multi-wavelength light source separated by the AWG is selected by an optical switch, and the like are conceivable.

  The dynamic path switching unit 30 includes a rewritable switching table 31 indicating the correspondence between the ONUs 10 and the output ports so that different OSUs 20 are close to the same load. The OSU 20 includes a counter 51 having a function of measuring and transmitting the measured traffic volume to the allocation circuit 50. Further, the measured traffic volume is newly collected from each counter 51, and the ONUs 10 are arranged so that different OSUs 20 approach the same load. An allocation circuit 50 that allocates the OSU 20 in units is provided.

  The calculation performed by the allocation circuit 50 is, for example, by counting the traffic passed in units of ONUs 10 and rearranging them according to the traffic volume, and then allocating the OSUs 20 in order from the ONU 10 having the smallest traffic volume. A method for making the total bandwidth uniform is conceivable.

  The allocation circuit 50 may determine the communication status of a plurality of OSUs 20 by monitoring information in the counter 51, and allocate OSUs 20 in units of ONUs 10 for backup against failures. Further, the allocation circuit 50 may or may not be included in the same apparatus as the OSU 20 including the counter 51 having the most transmission information.

  The counter 51 measures the amount of downstream traffic passing for each ONU 10 at a certain time. The measured traffic volume is transmitted to the allocation circuit 50. The allocation circuit 50 allocates the OSU 20 for each ONU 10 so that the total traffic amount of all the ONUs 10 accommodated among the different OSUs 20 approaches each other uniformly. Even when the result of the allocation calculation based on the past traffic measurement amount is applied to the traffic after a certain time, if the time taken from the measurement to the switching is short, the traffic amount between a plurality of different OSUs 20 can be made uniform. After determining the assignment, the correspondence relationship between the ONU 10 and the output port is transmitted to the switching table 31 in the dynamic path switching unit 30, and the relationship between the ONU 10 and the reception wavelength is transmitted to the OSU 20. The OSU 20 that has received the transmission information transmits the relationship between the ONU 10 and the reception wavelength to the ONU 10 and changes the wavelength variable filter 12 in the ONU 10. According to the transmitted allocation information, the output port is changed by the dynamic path switching unit 30 and the reception wavelength is changed by the ONU 10, thereby changing the connection between the OSU 20 and the ONU 10 and changing the accommodated OSU 20. The change in the allocation of the OSU 20 for each ONU 10 is repeated at regular time intervals in accordance with changes in traffic conditions.

  The present invention assigns the OSU 20 accommodated for each ONU 10 in accordance with the load on the downlink signal, and changes the OSU 20 accommodated for each ONU 10 so that the load between the different OSUs 20 becomes uniform. It is possible. Further, according to the present invention, it is possible to switch to a redundant system in response to a failure of the OSU 20.

(Second Embodiment)
FIG. 3 is a block diagram illustrating a configuration example of an optical communication system according to the second embodiment of the present invention. FIG. 4 shows an example of a signal according to the present embodiment, and a description is given below. In each ONU 10, the electrical signal UE _{ONU # 1} ... UE _{ONU # J} is input to the wavelength variable transmitter 13. Each wavelength variable transmitter 13 selects a wavelength allocated from the allocation circuit 50 every time and outputs an optical signal such as UL _{ONU # 1} ... UL _{ONU # J.} The optical signal output by the different wavelengths of the are multiplexed with the optical splitter _41, a WDM / TDM signal as _{U SP,} input to each OSU20. At a wavelength filter 22 in each OSU20, transmitted by selecting one wavelength signals which are determined as _{UL OSU # 1 ··· UL OSU #} K from _{U SP} is WDM / TDM signal. The receiver 23 receives the optical signals UL _{OSU # 1} ... UL _{OSU # K} and converts them into electrical signals UE _{OSU # 1} ... UE _{OSU # K.}

  It is assumed that the load between a plurality of different OSUs 20 is controlled only for the upstream traffic, the downstream traffic is changed in accordance with the upstream traffic, and the same OSU 20 is accommodated for both upstream and downstream traffic. . Since downlink traffic is the same as that of the optical communication system described in the first embodiment, mainly uplink traffic will be described.

  The optical communication system of the present embodiment includes a dynamic path switching unit 30, an OSU 20, an optical splitter 41, and an ONU 10, and the dynamic path switching unit 30 may be included in the same apparatus as the OSU 20 or separated from the OSU 20. It may be included in the host device. One optical splitter 41 may be used as one stage, or a plurality of optical splitters 41 may be arranged in series to form a plurality of stages.

  Each ONU 10 is accommodated in the OSU 20 allocated by the allocation circuit 50 and selectively transmits traffic having the same wavelength as the received wavelength of the accommodated OSU 20. Each ONU 10 includes a variable wavelength transmitter 13, and uses a wavelength equal to the reception wavelength set by the OSU 20 in which traffic is accommodated, and further transmits a signal at a time determined by the accommodated OSU 20. The optical splitter 41 branches and transfers the same signal to all the OSUs 20.

A plurality of different OSUs 20 are provided with wavelength filters 22 set to different reception wavelengths λ _n (n = 1, 2,..., K), and receive only signals of the set wavelengths. A user's signal is transmitted by the ONU 10, the transmission wavelength is changed, the optical splitter 41 is branched, and only a single wavelength set by the OSU 20 is selected and received, whereby the connection between the OSU 20 and the ONU 10 is changed. The OSU 20 to be accommodated is changed.

  The variable wavelength transmitter 13 may be, for example, a variable wavelength feedback DFB (distributed feedback) laser as a low-speed one, a DFB array type laser as a high-speed one, or a superstructure grating distributed reflector (SSG-DBR) laser.

  The dynamic path switching unit 30 includes a rewritable switching table 31 indicating the correspondence between the ONUs 10 and the input ports so that different OSUs 20 are close to the same load. The OSU 20 includes a counter 51 having a function of measuring and transmitting the measured traffic volume to the allocation circuit 50. Further, the measured traffic volume is newly collected from each counter 51, and the ONUs 10 are arranged so that different OSUs 20 approach the same load. An allocation circuit 50 that allocates the OSU 20 in units is provided.

  The allocation circuit 50 may determine the communication status of a plurality of OSUs 20 by monitoring information in the counter 51, and may allocate the OSU 20 for each ONU 10 for backup against a failure. Further, the allocation circuit 50 may or may not be included in the same apparatus as the OSU 20 including the counter 51 having the most transmission information. There are two possible methods for the counter 51. First, a counter 51 that counts the amount of upstream traffic that passes is provided in the OSU 20 and measured. Second, allocation information is obtained from a dynamic bandwidth allocation (DBA) circuit that determines a transmission permission time for each ONU 10. The DBA circuit is located in the OSU 20, and even if only dynamic band allocation of a user group accommodated in one OSU 20 is performed, the DBA circuit is located outside the OSU 20 and is accommodated in a plurality of OSUs 20. Group dynamic band allocation may be performed.

  The counter 51 measures the amount of upstream traffic passing in units of ONUs 10 at a certain time. The measured traffic volume is transmitted to the allocation circuit 50. The allocation circuit 50 allocates the OSU 20 for each ONU 10 so that the total traffic amount of all the ONUs 10 accommodated among the different OSUs 20 approaches each other uniformly. Even when the result of the allocation calculation based on the past traffic measurement amount is applied to the traffic after a certain time, if the time taken from the measurement to the switching is short, the traffic amount between a plurality of different OSUs 20 can be made uniform. Considering that allocation is possible, after the assignment is determined, the OSU 20 is informed of the relationship between the ONU 10 and the transmission wavelength. The OSU 20 that has received the transmission information transmits the relationship between the ONU 10 and the transmission wavelength to the ONU 10 and changes the wavelength variable transmitter 13 in the ONU 10. According to the transmitted allocation information, the ONU 10 changes the reception wavelength, thereby changing the connection between the OSU 20 and the ONU 10 and changing the accommodated OSU 20. The change in the allocation of the OSU 20 for each ONU 10 is repeated at regular time intervals in accordance with changes in traffic conditions.

In the present invention, the OSU 20 accommodated for each ONU 10 is also assigned to the upstream signal according to the load, and the OSU 20 accommodated for each ONU 10 is changed so that the load between the different OSUs 20 becomes uniform. It is possible to approach. Further, according to the present invention, it is possible to switch to a redundant system in response to a failure of the OSU 20.
Furthermore, the present invention enables the change of the downlink signal accommodation OSU 20 that is required when the uplink signal accommodation OSU 20 is changed by combining the dynamic path switching unit 30 and the wavelength tunable filter 12 in the ONU 10. .

(Third embodiment)
The optical communication system according to the third embodiment has a configuration in which the counter 51 is located in the dynamic path switching unit 30 instead of the OSU 20 in the optical communication system described in the first embodiment (FIG. 5).

  The counter 51 only needs to be able to measure the amount of downstream traffic that passes through the ONU 10 in a certain time, and may be located anywhere in the dynamic route switching unit 30. One or a plurality of them may be used.

  The allocation circuit 50 uses the measured amount of downlink traffic transmitted from the counter 51 in the dynamic path switching unit 30, and the total traffic amount of all the ONUs 10 accommodated by each of the different OSUs 20 approaches uniformly. As described above, the OSU 20 is assigned to each ONU 10. The allocation circuit 50 may or may not be included in the same apparatus as the dynamic path switching unit 30 including the counter 51 having the most transmission information.

  In the present invention, since the counter 51 is arranged in the dynamic path switching unit 30, the traffic amount of each OSU 20 can be measured using the common counter 51.

(Fourth embodiment)
The optical communication system according to the fourth embodiment has a configuration in which the counter 51 is located in the dynamic path switching unit 30 instead of the OSU 20 in the optical communication system described in the second embodiment (FIG. 6).

  The counter 51 only needs to be able to measure the amount of upstream traffic that passes through the ONU 10 in a certain time, and may be located anywhere in the dynamic route switching unit 30. One or a plurality of them may be used.

  The allocation circuit 50 uses the measured amount of uplink traffic transmitted from the counter 51 in the dynamic path switching unit 30 to make the total traffic amount of all the ONUs 10 accommodated by each of the different OSUs 20 uniform. As described above, the OSU 20 is assigned to each ONU 10. The allocation circuit 50 may or may not be included in the same apparatus as the dynamic path switching unit 30 including the counter 51 having the most transmission information.

  In the present invention, since the counter 51 is arranged in the dynamic path switching unit 30, the traffic amount of each OSU 20 can be measured using the common counter 51.

(Fifth embodiment)
The optical communication system according to the fifth embodiment has a configuration in which a revolving AWG 42 is used as a wavelength router instead of the optical splitter 41 in the optical communication system described in the first embodiment (FIG. 7). FIG. 8 shows an example of a signal according to the present embodiment, and a description is given below. From each OSU, the electrical signal DE _{OSU # 1} ... DE _{OSU # K} is input to the wavelength tunable transmitter 24, and the optical signal DL _{OSU # 1} ... Is transmitted using the wavelength allocated from the allocation circuit 50 for each frame. _-Converted and output as DL _{OSU # K.} DL _{OSU # 1} ... DL _{OSU # K} passes through the circulating AWG 42 and is output from an output port that is uniquely determined by the input port and wavelength. The signal after the recurring AWG 42 is changed in wavelength by the change of the accommodation OSU 20 as DL _{ONU # 1} ... DL _{ONU # J} , but the signal is distributed for each user and arrives. The receiver 11 of each ONU 10 receives the arriving optical signal over the entire wavelength band, and converts it into electrical signals DE _{ONU # 1} ... DE _{ONU # J.}

A plurality of different OSUs 20 includes a wavelength variable transmitter 24 that can transmit different wavelengths λ _n (n = 1, 2,..., J) for each ONU 10, and changes the transmission wavelength according to the destination of the signal to be transmitted. The plurality of ONUs 10 are connected to the plurality of OSUs 20 via the circulating AWG 42, and the circulating AWG 42 transfers traffic to the output port uniquely determined from the input port and the signal wavelength.

  The wavelength tunable transmitter 24 in the OSU 20 transmits data using a different wavelength for each user. Since it is necessary to change the wavelength in units of frames, a high-speed one is required. As the wavelength tunable transmitter 24, for example, a DFB array type laser or an SSG-DBR laser can be considered.

  Each ONU 10 receives all incoming WDM / TDM signals. An output port of a user signal is changed by the dynamic path switching unit 30, a transmission wavelength is changed by the wavelength variable transmitter 24 by each accommodated OSU 20, and an arbitrary ONU 10 is transmitted by the circulating AWG 42 according to the wavelength. The OSU 20 to be accommodated is changed by the transfer and the connection between the OSU 20 and the ONU 10 being changed.

  FIG. 9 shows an example of wavelength routing function characteristics of the recurring AWG 42. The input wavelength to the revolving AWG 42 is (p: wavelength number, q: input port number). Multiple wavelengths input from one input port are demultiplexed and output to different output ports. At this time, the output wavelength has a periodic characteristic with respect to the position of the input port.

  In the present invention, since the circulating AWG 42 is used as a wavelength router instead of the optical splitter 41 that branches the downstream signal, the transmission loss in the circulating AWG 42 can be reduced.

(Sixth embodiment)
The optical communication system according to the sixth embodiment has a configuration in which a revolving AWG 42 is used as a wavelength router instead of the optical splitter 41 in the optical communication system described in the second embodiment (FIG. 10). FIG. 11 shows an example of a signal according to the present embodiment, and a description is given below. In each ONU 10, the electrical signal UE _{ONU # 1} ... UE _{ONU # J} is input to the wavelength tunable transmitter 13, and the wavelength tunable transmitter 13 selects the wavelength allocated from the allocation circuit 50 for each time and selects UL. _{ONU # 1} ... Outputs an optical signal like UL _{ONU # J.} UL _{ONU # 1} ... UL _{ONU # J} passes through the circulating AWG 42 and is output from an output port uniquely determined by the input port and wavelength. The optical signal after the recurring AWG 42 is changed in wavelength by the change of the accommodation _{OSU 20 as} in UL _{OSU # 1} ... UL _{OSU # K} , but the signal is distributed for each user and arrives. The receiver 23 of each OSU 20 receives the arriving optical signal over the entire wavelength band, and converts it into electrical signals UE _{OSU # 1} ... UE _{OSU # K.}

  Since downlink traffic is the same as that of the optical communication system described in the fifth embodiment, mainly uplink traffic will be described.

Each ONU 10 includes a wavelength tunable transmitter 13 that can transmit different wavelengths λ _n (n = 1, 2,..., J) for each ONU 10, and is transmitted by a destination of a signal to be transmitted (accommodated OSU 20). The wavelength is changed, and a signal is transmitted at a time determined by the OSU 20 accommodated therein. The recursive AWG 42 forwards the traffic to the output port uniquely determined from the input port and the wavelength of the signal.

  The receivers 23 of a plurality of different OSUs 20 receive all WDM / TDM signals that arrive. A signal of a certain user is changed in transmission wavelength by the ONU 10, transferred to an arbitrary OSU 20 according to the wavelength by the circulating AWG 42, and the OSU 20 to be accommodated is changed by changing the connection between the OSU 20 and the ONU 10.

In the present invention, since the circulating AWG 42 is used as a wavelength router instead of the optical splitter 41 that branches the upstream signal, transmission loss in the circulating AWG 42 can be reduced.
Further, according to the present invention, by combining the dynamic path switching unit 30 and the wavelength tunable transmitter 21 in the OSU 20, it is possible to change the accommodation OSU for the downlink signal that is required when the accommodation OSU for the uplink signal is changed. To do.

(Seventh embodiment)
The optical communication system according to the seventh embodiment has a configuration in which the counter 51 is located in the dynamic path switching unit 30 instead of the OSU 20 in the optical communication system described in the fifth embodiment (FIG. 12).

  The counter 51 only needs to be able to measure the amount of downstream traffic passing in units of the ONU 10 in a certain time, and may be located anywhere in the dynamic route switching unit 30. One or a plurality of them may be used.

  The allocation circuit 50 uses the measured amount of downlink traffic transmitted from the counter 51 in the dynamic path switching unit 30, and the total traffic amount of all the ONUs 10 accommodated by each of the different OSUs 20 approaches uniformly. As described above, the OSU 20 is assigned to each ONU 10. The allocation circuit 50 may or may not be included in the same apparatus as the dynamic path switching unit 30 including the counter 51 having the most transmission information.

  In the present invention, since the counter 51 is arranged in the dynamic path switching unit 30, the traffic amount of each OSU 20 can be measured using the common counter 51.

(Eighth embodiment)
The optical communication system according to the eighth embodiment has a configuration in which the counter 51 is located in the dynamic path switching unit 30 instead of the OSU 20 in the optical communication system described in the sixth embodiment (FIG. 13).

  The counter 51 only needs to be able to measure the amount of upstream traffic that passes through the ONU 10 in a certain time, and may be located anywhere in the dynamic route switching unit 30. One or a plurality of them may be used.

  The allocation circuit 50 uses the measured amount of uplink traffic transmitted from the counter 51 in the dynamic path switching unit 30 to make the total traffic amount of all the ONUs 10 accommodated by each of the different OSUs 20 uniform. As described above, the OSU 20 is assigned to each ONU 10. The allocation circuit 50 may or may not be included in the same apparatus as the dynamic path switching unit 30 including the counter 51 having the most transmission information.

  In the present invention, since the counter 51 is arranged in the dynamic path switching unit 30, the traffic amount of each OSU 20 can be measured using the common counter 51.

(Ninth embodiment)
The optical communication system in the ninth embodiment is a configuration in which the optical splitter 43 is used between the circulating AWG 42 and the ONU 10 in the optical communication system described in the fifth embodiment (FIG. 14). The OSU 20 transfers the traffic received from the dynamic path switching unit 30 using the wavelength at which the traffic arrives at the target ONU 10 after passing through the recursive AWG 42. The recursive AWG 42 transfers the traffic transmitted by the OSU 20 to the output port uniquely determined from the input port and the signal wavelength. The ONU 10 receives traffic having the same wavelength as the transmission wavelength of the OSU 20 assigned by the assignment circuit 50.

  An optical splitter 44 may be used between the orbiting AWG 42 and the OSU 20, and a plurality of orbiting AWGs 42 may be used in parallel. The number of optical splitters 43 used between the circulating AWG 42 and the ONU 10 may be one, or may be a plurality of stages arranged in series (FIG. 15).

  In the configuration of FIG. 15, users are concentrated using the multistage optical splitter 41, so that an optical amplifier capable of satisfying the specified reception sensitivity when an optical amplifier is required for loss budget expansion. The transmission loss before and after can be selected relatively freely according to the arrangement position of the optical amplifier, and by determining the optimum arrangement position of the optical amplifier from the concentration ratio and the performance of the optical amplifier, the minimum number of optical amplifiers is used. Thus, a prescribed reception sensitivity can be achieved, and a power-saving and economical system can be configured. Further, when an optical amplifier is placed between the circulating AWG 42 and the OSU 20, the upstream signal input to the optical amplifier is only a signal communicating with the single OSU 20, so there is no need to amplify signals of a plurality of wavelengths simultaneously. A stable gain can be obtained.

A plurality of different OSUs 20 includes a wavelength variable transmitter 24 capable of transmitting wavelengths λ _n (n = 1, 2,..., L) (l: an integer satisfying k ≦ l ≦ j), and a destination of a signal to be transmitted To change the transmission wavelength. The plurality of ONUs 10 are connected to the plurality of OSUs 20 via the optical splitters 43 and 44 and the revolving AWG 42. The circular AWG 42 transfers the traffic to the output port uniquely determined from the input port and the wavelength of the signal, and the optical splitter 43 branches and transfers the same signal to a plurality of ONUs 10 connected to the same output port of the circular AWG 42.

  Each ONU 10 is equipped with a wavelength tunable filter 12 and extracts only the wavelength including the own signal from the WDM / TDM signal and extracts only the own signal from the TDM signal. An output port of a user's signal is changed by the dynamic path switching unit 30, a transmission wavelength is changed by the wavelength variable transmitter 24 by each accommodated OSU 20, and an arbitrary optical splitter according to the wavelength by the circulating AWG 42. The optical splitter 43 branches traffic from a plurality of different OSUs 20 to a plurality of different ONUs 10, changes the reception wavelength at the ONU 10, and changes the connection between the OSU 20 and the ONU 10. change.

  14 to 15 show a configuration in which each ONU 10 connected to the same port of the circulating AWG 42 can communicate with a different OSU 20 by including the wavelength tunable filter 12 in the ONU 10. The wavelength tunable filter 12 is included in the ONU 10. A configuration in which the OSU 20 to be connected is changed for each group of ONUs 10 connected to the same port of the circulating AWG 42 without being provided, and the load of the OSU 20 is distributed is also possible.

  In the present invention, since the optical splitter 43 is used between the circulating AWG 42 and the ONU 10, the users are concentrated using not only the circulating AWG 42 but also the optical splitter 41. Therefore, the circulating AWG 42 corresponds to the number of users to be concentrated. Therefore, it is possible to reduce the number of necessary wavelengths and accordingly the number of wavelengths, and it is possible to use an economical AWG 42 and a wavelength tunable device.

(Tenth embodiment)
The optical communication system in the tenth embodiment is a configuration in which the optical splitter 43 is used between the circulating AWG 42 and the ONU 10 in the optical communication system described in the sixth embodiment (FIG. 16).

  An optical splitter 44 may be used between the circulating AWG 42 and the OSU 20, and a plurality of circulating AWGs may be used in parallel. The number of optical splitters 43 used between the circulating AWG 42 and the ONU 10 may be one, or a plurality of optical splitters 43 may be arranged in series. Since downlink traffic is the same as that of the optical communication system described in the ninth embodiment, mainly uplink traffic will be described.

Each ONU 10 includes a wavelength variable transmitter 13 capable of transmitting wavelengths λ _n (n = 1, 2,..., L) (l: an integer satisfying k ≦ l ≦ j), and a destination (accommodation) of a signal to be transmitted. The transmission wavelength is changed by the OSU 20), and a signal is transmitted at a time determined by the stored OSU 20. The optical splitter 43 bundles signals from a plurality of ONUs 10 and transfers them to the input port of the circulating AWG 42. The circulating AWG 42 transfers traffic to an output port that is uniquely determined from the input port and the wavelength of the signal.

  Different OSUs 20 receive all incoming WDM / TDM signals. A user's signal is changed in transmission wavelength at the ONU 10, concentrated by the optical splitter 43, transferred to an arbitrary destination by the circulating AWG 42, and the OSU 20 accommodated by the change in the connection between the OSU 20 and the ONU 10 is changed. To do.

  FIG. 16 shows a configuration in which each ONU 10 connected to the same port of the circulating AWG 42 can communicate with a different OSU 20 by providing the wavelength tunable filter 12 in the ONU 10, but without the wavelength tunable filter 12 in the ONU 10. A configuration in which the OSU 20 connected to each ONU group connected to the same port of the circulating AWG 42 is changed to distribute the load of the OSU 20 is also possible.

In the present invention, since the optical splitter 43 is used between the circulating AWG 42 and the ONU 10, the users are concentrated using not only the circulating AWG 42 but also the optical splitter 43. Therefore, the circulating AWG 42 corresponds to the number of users to be concentrated. Therefore, it is possible to reduce the number of necessary wavelengths and accordingly the number of wavelengths, and it is possible to use an economical AWG 42 and a wavelength tunable device.
Further, the present invention combines the dynamic path switching unit 30, the variable wavelength transmitter 24 in the OSU 20, and the variable wavelength filter 12 in the ONU 10, so that the downstream signal required in accordance with the change of the accommodated OSU 20 for the upstream signal The accommodation OSU 20 can be changed.

(Eleventh embodiment)
The optical communication system according to the eleventh embodiment has a configuration in which the counter 51 is located in the dynamic path switching unit 30 instead of the OSU 20 in the optical communication system described in the ninth embodiment (FIG. 17).

  The counter 51 only needs to be able to measure the amount of downstream traffic passing in units of the ONU 10 in a certain time, and may be located anywhere in the dynamic route switching unit 30. One or a plurality of them may be used.

  The allocation circuit 50 uses the measured amount of downlink traffic transmitted from the counter 51 in the dynamic path switching unit 30, and the total traffic amount of all the ONUs 10 accommodated by each of the different OSUs 20 approaches uniformly. As described above, the OSU 20 is assigned to each ONU 10. The allocation circuit 50 may or may not be included in the same apparatus as the dynamic path switching unit 30 including the counter 51 having the most transmission information.

  In the present invention, since the counter 51 is arranged in the dynamic path switching unit 30, the traffic amount of each OSU 20 can be measured using the common counter 51.

(Twelfth embodiment)
The optical communication system according to the twelfth embodiment has a configuration in which the counter 51 is located in the dynamic path switching unit 30 instead of the OSU 20 in the optical communication system described in the tenth embodiment (FIG. 18).

  The counter 51 only needs to be able to measure the amount of upstream traffic that passes through the ONU 10 in a certain time, and may be located anywhere in the dynamic route switching unit 30. One or a plurality of them may be used.

  The allocation circuit 50 uses the measured amount of uplink traffic transmitted from the counter 51 in the dynamic path switching unit 30 to make the total traffic amount of all the ONUs 10 accommodated by each of the different OSUs 20 uniform. As described above, the OSU 20 is assigned to each ONU 10. The allocation circuit 50 may or may not be included in the same apparatus as the dynamic path switching unit 30 including the counter 51 having the most transmission information.

  In the present invention, since the counter 51 is arranged in the dynamic path switching unit 30, the traffic amount of each OSU 20 can be measured using the common counter 51.

(13th Embodiment)
The optical communication system according to the thirteenth embodiment is the same as the optical communication system according to the ninth embodiment, but uses one optical splitter 44 between the OSU 20 and the revolving AWG, and k (k is an integer satisfying 1 <k). In this configuration, the AWG 45 of 1 × l (l: integer with k ≦ l ≦ j) port is used as a wavelength router instead of the recurring AWG 42 by aggregating traffic from the OSU 20 of the network and transferring the traffic to the AWG 45 (FIG. 19). ). One optical splitter 43 used between the AWG 45 and the ONU 10 may be used as one stage, or a plurality of optical splitters may be arranged in series to form a plurality of stages.

  The OSU 20 transfers the traffic received from the dynamic path switching unit 30 using the wavelength at which the traffic arrives at the target ONU 10 after passing through the 1 × 1 port AWG 45. The 1 × 1 port AWG 45 transfers the traffic transmitted by the OSU 20 to the output port uniquely determined from the input port and the signal wavelength. The ONU 10 receives the arrived signal.

A plurality of different OSUs 20 includes a wavelength variable transmitter 24 capable of transmitting wavelengths λ _n (n = 1, 2,..., L), and changes the transmission wavelength depending on the destination of the signal to be transmitted. The plurality of ONUs 10 are connected to the plurality of OSUs 20 via the ONU 10 side optical splitter 43, the 1 × 1 port AWG 45, and the OSU 20 side optical splitter 44. The OSU 20 side splitter aggregates the traffic from the k OSUs 20 and transfers the aggregated traffic to the 1 × 1 port AWG 45. The 1 × 1 port AWG 45 transfers the traffic to the output port uniquely determined from the input port and the signal wavelength. 43 branches and transfers the same signal to a plurality of ONUs 10 connected to the same output port of the 1 × 1 port AWG 45.

  Each ONU 10 receives the arriving signal.

  The output port of a certain user's signal is changed by the dynamic path switching unit 30, the transmission wavelength is changed by the wavelength tunable transmitter 24 by each accommodated OSU 20, and the signal from the k OSUs 20 by the OSU 20 side optical splitter 44 is changed. The traffic is aggregated and transferred to the AWG 45, transferred to an arbitrary optical splitter 43 according to the wavelength by the 1 × 1 port AWG 45, and traffic directed from the different OSUs 20 to the different ONUs 10 is branched by the ONU 10 side optical splitter 43. The received wavelength is changed by the ONU 10, and the OSU 20 to be accommodated is changed by changing the connection between the OSU 20 and the ONU 10.

  When the 1 × 1 port AWG45 is used, since it is input from one port, signals of the same wavelength are output from the same ONU 10 side port. Therefore, the change of the OSU 20 in which the downlink traffic is accommodated can be performed only by the group of users under the ONU 10 side port of the same AWG 45.

  Since the present invention uses the 1 × l port AWG45 instead of the recurring AWG 42, it is possible to condense using an inexpensive 1 × l port AWG without using an expensive recurring AWG, and only an optical splitter. The transmission loss can be reduced as compared with the case where the lines are collected using the.

(Fourteenth embodiment)
The optical communication system according to the fourteenth embodiment is the optical communication system according to the tenth embodiment, wherein one optical splitter 44 is used between the OSU 20 and the revolving AWG 42 to aggregate traffic from a plurality of OSUs 20 into the AWG 45. In this configuration, instead of the recurring AWG 42, an AWG 45 of 1 × l (l: integer with k ≦ l ≦ j) port is used as a wavelength router by forwarding (FIG. 20). One optical splitter 43 used between the AWG 45 and the ONU 10 may be used as one stage, or a plurality of optical splitters may be arranged in series to form a plurality of stages. Since downlink traffic is the same as that of the optical communication system described in the thirteenth embodiment, mainly uplink traffic will be described.

  A plurality of ONUs 10 connected to the same ONU 10 side port of the 1 × 1 port AWG 45 are all set to the same transmission wavelength, and transmit signals using wavelengths that can be output from one OSU 20 side port. Each ONU 10 transmits a signal at a time determined by the accommodated OSU 20. The ONU 10 side optical splitter 43 bundles signals from a plurality of ONUs 10 and transfers them to the input port of the 1 × 1 port AWG 45. The 1 × 1 port AWG 45 transfers traffic to the output port uniquely determined from the input port and the wavelength of the signal. The OSU 20 side optical splitter 44 branches and transfers the traffic from the 1 × 1 port AWG 45 to all the OSUs 20.

A plurality of different OSUs 20 includes a wavelength tunable filter 25 that can select different wavelengths λ _n (n = 1, 2,..., L), and selectively receive only arbitrary wavelengths according to time. A user's signal is transmitted by the ONU 10, concentrated by the ONU 10 side optical splitter 43, aggregated into one output port by the 1 × 1 port AWG 45, branched by the OSU 20 side optical splitter 44, and only a given wavelength is transmitted by the OSU 20. By selectively receiving, the OSU 20 to be accommodated is changed by changing the connection between the OSU 20 and the ONU 10.

  Since the 1 × 1 port AWG 45 outputs from one port in response to input from a plurality of ports, the plurality of ONUs 10 connected to the same ONU 10 side port are set to the same transmission wavelength. Therefore, the change of the OSU 20 that accommodates the upstream traffic can be performed only for the group of users under the ONU 10 side port of the same AWG 45.

Since the present invention uses the 1 × l port AWG45 instead of the recurring AWG 42, it is possible to condense using an inexpensive 1 × l port AWG without using an expensive recurring AWG, and only an optical splitter. The transmission loss can be reduced as compared with the case where the lines are collected using the.
Further, according to the present invention, by combining the dynamic path switching unit 30 and the variable wavelength transmitter 24 in the OSU 20, it is possible to change the accommodation OSU 20 for downstream signals, which is required when the accommodation OSU 20 for upstream signals is changed. To do.

(Fifteenth embodiment)
The optical communication system in the fifteenth embodiment has a configuration in which the counter 51 is located in the dynamic path switching unit 30 instead of the OSU 20 in the optical communication system described in the thirteenth embodiment (FIG. 21). The counter 51 only needs to be able to measure the amount of downstream traffic passing in units of the ONU 10 in a certain time, and may be located anywhere in the dynamic route switching unit 30. One or a plurality of them may be used.

  The allocation circuit 50 uses the measured amount of downlink traffic transmitted from the counter 51 in the dynamic path switching unit 30, and the total traffic amount of all the ONUs 10 accommodated by each of the different OSUs 20 approaches uniformly. As described above, the OSU 20 is assigned to each ONU 10. The allocation circuit 50 may or may not be included in the same apparatus as the dynamic path switching unit 30 including the counter 51 having the most transmission information.

  In the present invention, since the counter 51 is arranged in the dynamic path switching unit 30, the traffic amount of each OSU 20 can be measured using the common counter 51.

(Sixteenth embodiment)
The optical communication system according to the sixteenth embodiment has a configuration in which the counter 51 is located in the dynamic path switching unit 30 instead of the OSU 20 in the optical communication system described in the fourteenth embodiment (FIG. 22). The counter 51 only needs to be able to measure the amount of upstream traffic that passes through the ONU 10 in a certain time, and may be located anywhere in the dynamic route switching unit 30. One or a plurality of them may be used.

  The allocation circuit 50 uses the measured amount of uplink traffic transmitted from the counter 51 in the dynamic path switching unit 30 to make the total traffic amount of all the ONUs 10 accommodated by each of the different OSUs 20 uniform. As described above, the OSU 20 is assigned to each ONU 10. The allocation circuit 50 may or may not be included in the same apparatus as the dynamic path switching unit 30 including the counter 51 having the most transmission information.

  In the present invention, since the counter 51 is arranged in the dynamic path switching unit 30, the traffic amount of each OSU 20 can be measured using the common counter 51.

  The present invention can be applied to the information communication industry.

10: ONU
11: Receiver 12: Wavelength variable filter 13: Wavelength variable transmitter 14: Transmitter 20: OSU
21: Wavelength variable transmitter 22: Wavelength filter 23: Receiver 24: Wavelength variable transmitter 25: Wavelength variable filter 30: Dynamic path switching unit 31: Switching tables 41, 43, 44: Optical splitter 42: Circulating AWG
45: AWG
50: Allocation circuit 51: Counter

Claims (10)

An optical communication system in which a parent node and a plurality of child nodes are connected via an optical fiber transmission line so that each child node can be accommodated in any parent node,
A counter that measures traffic per child node over an arbitrary period of time;
An allocation circuit for allocating a parent node in which a child node is accommodated so that each parent node approaches an equal load according to the traffic volume measured by the counter;
A dynamic path switching unit that receives traffic to a child node and outputs the traffic to the parent node assigned by the assignment circuit;
With
Each parent node forwards the traffic received from the dynamic path switching unit to the child node allocated from the allocation circuit,
Each child node receives the traffic transmitted from the parent node allocated from the allocation circuit,
And changing the output port in the dynamic path switching unit, and changes the transmission wavelength selecting the parent node, by changing the receiving wavelength selecting a child node, the parent node to be accommodated child nodes Ri temporally River ,
The allocation circuit counts traffic passed in units of child nodes, rearranges them according to the traffic volume, and then allocates the parent nodes in order from the child nodes having the smaller traffic volume. To
Optical communication system. An optical communication system in which a parent node and a plurality of child nodes are connected via an optical fiber transmission line so that each child node can be accommodated in any parent node,
A counter that measures traffic per child node over an arbitrary period of time;
An allocation circuit for allocating a parent node in which a child node is accommodated so that each parent node approaches an equal load according to the traffic volume measured by the counter;
A dynamic path switching unit that receives traffic to a child node and outputs the traffic to the parent node assigned by the assignment circuit;
With
Each parent node forwards the traffic received from the dynamic path switching unit to the child node allocated from the allocation circuit,
Each child node receives the traffic transmitted from the parent node allocated from the allocation circuit,
By changing the output port in the dynamic path switching unit, changing the transmission wavelength selected by the parent node, and changing the reception wavelength selected by the child node, the parent node accommodated by the child node changes in time,
In the optical fiber transmission line, each parent node and each child node are connected via an optical splitter,
The parent node forwards the traffic received from the dynamic path switching unit using a wavelength predetermined for each parent node,
The optical splitter branches and forwards the traffic transmitted by the parent node to each child node,
Each child node selectively receives traffic having the same wavelength as the transmission wavelength of the parent node assigned by the assignment circuit.
Light communication system that is characterized in that. An optical communication system in which a parent node and a plurality of child nodes are connected via an optical fiber transmission line so that each child node can be accommodated in any parent node,
A counter that measures traffic per child node over an arbitrary period of time;
An allocation circuit for allocating a parent node in which a child node is accommodated so that each parent node approaches an equal load according to the traffic volume measured by the counter;
A dynamic path switching unit that receives traffic to a child node and outputs the traffic to the parent node assigned by the assignment circuit;
With
Each parent node forwards the traffic received from the dynamic path switching unit to the child node allocated from the allocation circuit,
Each child node receives the traffic transmitted from the parent node allocated from the allocation circuit,
By changing the output port in the dynamic path switching unit, changing the transmission wavelength selected by the parent node, and changing the reception wavelength selected by the child node, the parent node accommodated by the child node changes in time,
In the optical fiber transmission line, each parent node and each child node are connected via a common wavelength router,
The parent node transfers the traffic received from the dynamic path switching unit using the wavelength at which the traffic arrives at the target child node after passing through the wavelength router,
The wavelength router forwards the traffic transmitted by the parent node to the output port uniquely determined from the input port and the signal wavelength,
Each child node receives the arriving signal,
Light communication system that is characterized in that. An optical communication system in which a parent node and a plurality of child nodes are connected via an optical fiber transmission line so that each child node can be accommodated in any parent node,
A counter that measures traffic per child node over an arbitrary period of time;
An allocation circuit for allocating a parent node in which a child node is accommodated so that each parent node approaches an equal load according to the traffic volume measured by the counter;
A dynamic path switching unit that receives traffic to a child node and outputs the traffic to the parent node assigned by the assignment circuit;
With
Each parent node forwards the traffic received from the dynamic path switching unit to the child node allocated from the allocation circuit,
Each child node receives the traffic transmitted from the parent node allocated from the allocation circuit,
By changing the output port in the dynamic path switching unit, changing the transmission wavelength selected by the parent node, and changing the reception wavelength selected by the child node, the parent node accommodated by the child node changes in time,
In the optical fiber transmission line, each parent node is connected to a common wavelength router, and each port of the wavelength router is connected to a plurality of child nodes via an optical splitter,
The parent node transfers the traffic received from the dynamic path switching unit using the wavelength at which the traffic arrives at the target child node after passing through the wavelength router,
The wavelength router forwards the traffic transmitted by the parent node to the output port uniquely determined from the input port and the wavelength of the signal,
The child node receives traffic having the same wavelength as the transmission wavelength of the parent node assigned by the assignment circuit.
Light communication system that is characterized in that. An optical communication system in which a parent node and a plurality of child nodes are connected via an optical fiber transmission line so that each child node can be accommodated in any parent node,
A counter that measures traffic per child node over an arbitrary period of time;
An allocation circuit for allocating a parent node in which a child node is accommodated so that each parent node approaches an equal load according to the traffic volume measured by the counter;
A dynamic path switching unit that receives traffic to a child node and outputs the traffic to the parent node assigned by the assignment circuit;
With
Each parent node forwards the traffic received from the dynamic path switching unit to the child node allocated from the allocation circuit,
Each child node receives the traffic transmitted from the parent node allocated from the allocation circuit,
By changing the output port in the dynamic path switching unit, changing the transmission wavelength selected by the parent node, and changing the reception wavelength selected by the child node, the parent node accommodated by the child node changes in time,
In the optical fiber transmission line, each parent node is connected to a common first optical splitter, the first optical splitter is connected to a common wavelength router, and a plurality of ports of the wavelength router are connected via an optical splitter. Connected to the child node of
The parent node transfers the traffic received from the dynamic path switching unit using the wavelength at which the traffic arrives at the target child node after passing through the wavelength router,
The wavelength router forwards the traffic transmitted by the parent node to the output port uniquely determined from the input port and the wavelength of the signal,
The child node receives traffic having the same wavelength as the transmission wavelength of the parent node assigned by the assignment circuit.
Light communication system that is characterized in that. An optical communication method in an optical communication system in which a parent node and a plurality of child nodes are connected via an optical fiber transmission line so that each child node can be accommodated in any parent node,
An allocation procedure that measures traffic for each child node over an arbitrary time and assigns a parent node in which the child node is accommodated so that each parent node approaches an equal load according to the measured traffic volume;
A dynamic route switching procedure for outputting the traffic of the child node to the parent node assigned in the assignment procedure;
Each parent node transfers the traffic of the child node assigned in the assignment procedure to the child node assigned from the assignment circuit, and each child node transmits the traffic transmitted from the parent node assigned in the assignment procedure. Receive traffic, and
In order,
And changing the output port in the dynamic path switch procedure, a change in the transmit wavelength to be selected by the parent node, by changing the receiving wavelength selecting a child node, the parent node to be accommodated child nodes Ri temporally River ,
In the assignment procedure, the traffic passed in units of child nodes is counted, rearranged according to the traffic volume, and then the parent nodes are assigned in order from the child node having the smaller traffic volume. Optical communication method. An optical communication method in an optical communication system in which a parent node and a plurality of child nodes are connected via an optical fiber transmission line so that each child node can be accommodated in any parent node,
An allocation procedure that measures traffic for each child node over an arbitrary time and assigns a parent node in which the child node is accommodated so that each parent node approaches an equal load according to the measured traffic volume;
A dynamic route switching procedure for outputting the traffic of the child node to the parent node assigned in the assignment procedure;
Each parent node transfers the traffic of the child node assigned in the assignment procedure to the child node assigned from the assignment circuit, and each child node transmits the traffic transmitted from the parent node assigned in the assignment procedure. Receive traffic, and
In order,
By changing the output port in the dynamic route switching procedure, changing the transmission wavelength selected by the parent node, and changing the reception wavelength selected by the child node, the parent node accommodated by the child node changes in time,
In the optical fiber transmission line, each parent node and each child node are connected via an optical splitter,
In the traffic transmission procedure,
The parent node forwards the traffic of the child node assigned in the assignment procedure using a wavelength predetermined for each parent node,
The optical splitter branches and forwards the traffic transmitted by the parent node to each child node,
Each child node selectively receives traffic having the same wavelength as the transmission wavelength of the parent node allocated in the allocation procedure.
Optical communication with how to characterized in that. An optical communication method in an optical communication system in which a parent node and a plurality of child nodes are connected via an optical fiber transmission line so that each child node can be accommodated in any parent node,
An allocation procedure that measures traffic for each child node over an arbitrary time and assigns a parent node in which the child node is accommodated so that each parent node approaches an equal load according to the measured traffic volume;
A dynamic route switching procedure for outputting the traffic of the child node to the parent node assigned in the assignment procedure;
Each parent node transfers the traffic of the child node assigned in the assignment procedure to the child node assigned from the assignment circuit, and each child node transmits the traffic transmitted from the parent node assigned in the assignment procedure. Receive traffic, and
In order,
By changing the output port in the dynamic route switching procedure, changing the transmission wavelength selected by the parent node, and changing the reception wavelength selected by the child node, the parent node accommodated by the child node changes in time,
In the optical fiber transmission line, each parent node and each child node are connected via a common wavelength router,
In the traffic transmission procedure,
The parent node transfers the traffic received in the dynamic route switching procedure using the wavelength at which the traffic arrives at the target child node after passing through the wavelength router,
The wavelength router forwards the traffic transmitted by the parent node to the output port uniquely determined from the input port and the signal wavelength,
Each child node receives the arriving signal,
Optical communication with how to characterized in that. An optical communication method in an optical communication system in which a parent node and a plurality of child nodes are connected via an optical fiber transmission line so that each child node can be accommodated in any parent node,
An allocation procedure that measures traffic for each child node over an arbitrary time and assigns a parent node in which the child node is accommodated so that each parent node approaches an equal load according to the measured traffic volume;
A dynamic route switching procedure for outputting the traffic of the child node to the parent node assigned in the assignment procedure;
Each parent node transfers the traffic of the child node assigned in the assignment procedure to the child node assigned from the assignment circuit, and each child node transmits the traffic transmitted from the parent node assigned in the assignment procedure. Receive traffic, and
In order,
By changing the output port in the dynamic route switching procedure, changing the transmission wavelength selected by the parent node, and changing the reception wavelength selected by the child node, the parent node accommodated by the child node changes in time,
In the optical fiber transmission line, each parent node is connected to a common wavelength router, and each port of the wavelength router is connected to a plurality of child nodes via an optical splitter,
In the traffic transmission procedure,
The parent node transfers the traffic received in the dynamic route switching procedure using the wavelength at which the traffic arrives at the target child node after passing through the wavelength router,
The wavelength router forwards the traffic transmitted by the parent node to the output port uniquely determined from the input port and the wavelength of the signal,
Each child node receives traffic having the same wavelength as the transmission wavelength of the parent node assigned in the assignment procedure.
Optical communication with how to characterized in that. An optical communication method in an optical communication system in which a parent node and a plurality of child nodes are connected via an optical fiber transmission line so that each child node can be accommodated in any parent node,
An allocation procedure that measures traffic for each child node over an arbitrary time and assigns a parent node in which the child node is accommodated so that each parent node approaches an equal load according to the measured traffic volume;
A dynamic route switching procedure for outputting the traffic of the child node to the parent node assigned in the assignment procedure;
Each parent node transfers the traffic of the child node assigned in the assignment procedure to the child node assigned from the assignment circuit, and each child node transmits the traffic transmitted from the parent node assigned in the assignment procedure. Receive traffic, and
In order,
By changing the output port in the dynamic route switching procedure, changing the transmission wavelength selected by the parent node, and changing the reception wavelength selected by the child node, the parent node accommodated by the child node changes in time,
In the optical fiber transmission line, each parent node is connected to a common first optical splitter, the first optical splitter is connected to a common wavelength router, and a plurality of ports of the wavelength router are connected via an optical splitter. Connected to the child node of
In the traffic transmission procedure,
The parent node transfers the traffic received in the dynamic route switching procedure using the wavelength at which the traffic arrives at the target child node after passing through the wavelength router,
The wavelength router forwards the traffic transmitted by the parent node to the output port uniquely determined from the input port and the wavelength of the signal,
The child node receives traffic having the same wavelength as the transmission wavelength of the parent node allocated in the allocation procedure.
Optical communication with how to characterized in that.

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