JP2009224951A - Optical coupling system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To easily form an optical static network which connects each of a plurality of nodes independently to another node in one-to-one relation. <P>SOLUTION: The optical coupling system includes the plurality of nodes such as a node 110 and a node 112 or the like, a hub 130, and an optical back plane 80. The hub has a static network 132 comprising an optical wiring board such as a flexible optical fiber wiring board, in which each of the plurality of nodes are independently connected to another node in one-to-one relation. The optical back plane 80 is provided with an optical fiber plate for optically connecting the plurality of nodes and the hub. Each node is provided with a packet signal processing circuit for processing transmission packet signals and reception packet signals and a photoelectric converter. When the signals are sent from one node to another node, the signals transmitted from the one node are inputted through the static network provided in the hub and the optical back plane to another node. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an optical coupling system for realizing information transmission between nodes, which are a plurality of electric circuit subsystems, using an optical transmission line via a hub.

  In recent years, the amount of information distributed through networks has increased due to the expansion of broadband networks and the increase in applications that require a large amount of high-speed packet transfer such as moving image transfer. As a result, it is possible to improve the information processing capacity of nodes, which are electrical circuit subsystems that are units for transmitting information in relay device systems such as routers on the Internet, and hubs that are subsystems that mediate communication between nodes. It has been demanded. However, the transmission speed limit due to the electric signal is a barrier to the improvement of the information processing capacity of the entire system. In order to overcome this barrier, it is effective to interconnect the nodes with an optical transmission line.

  Generally, electrical signals are used for such interconnection between nodes. On the other hand, a system achieved by inserting and connecting a node and a hub via an optical socket to an optical backplane laid with an optical transmission line such as an optical fiber has also been proposed (for example, Patent Documents 1 to 3). See). In this system, nodes and hubs are provided with photoelectric converters. The node is connected to an external network, and a group of LSIs that perform packet processing, elements such as photoelectric converters are arranged on a single printed wiring board, and the elements are formed on the printed wiring board. They are connected by an electric signal transmission line and an optical signal transmission line.

  With reference to FIG. 1, a basic configuration of a conventional optical coupling system using an interconnection technology between nodes and an outline of the operation will be described. FIG. 1 is a schematic block diagram of a conventional optical coupling system using a hub having a dynamic network. The dynamic network is a wiring network that selects a transmission line that connects a transmission-side node and a reception-side node based on a switch operation. For example, the dynamic network is realized by a crosspoint switch LSI that operates electrically as described later. In FIG. 1, the connection between the elements provided in the block is not shown.

  The configuration feature of the conventional optical coupling system shown in FIG. 1 is that a cross-point switch is used to connect each node of a plurality of nodes in a one-to-one relationship and execute communication. The transmission line connecting the node on the transmission side and the node on the reception side is selected. That is, the conventional optical coupling system is characterized in that a dynamic network is used to select a transmission path for connecting nodes.

  In the conventional optical coupling system shown in FIG. 1, the node 10 and the node 60 are coupled via a hub 30. The hub 30 includes a dynamic network 30-1 and a photoelectric converter 30-2 realized by a crosspoint switch LSI or the like. The node includes a packet signal processing circuit that processes a transmission packet signal that is a transmission signal and a reception packet signal that is a reception signal, and a photoelectric converter. That is, the node 10 includes a packet signal processing circuit 10-1 and a photoelectric converter 10-2, and the node 60 includes a packet signal processing circuit 60-1 and a photoelectric converter 60-2. In FIG. 1, the node 10 and the node 60 are shown as representatives via the hub 30, but the number of nodes provided in the optical coupling system is not limited to these two. It doesn't matter.

  When a signal is sent from the node 10 to the node 60, the transmission line for outputting the signal transmitted from the node 10 to the node 60 is selected by the dynamic network 30-1 including the hub 30. Output to the node 60 via the optical backplane 80. In this way, communication from the node 10 to the notebook 60 is performed.

  As shown in FIG. 1, in the conventional optical coupling system, photoelectric conversion is performed in both the node and the hub. The photoelectric conversion at the node is performed from the necessity of converting the received packet signal received in the form of an optical packet signal into an electric packet signal because the processing of the received packet signal at the node is performed by electrical means. With the current technology, it is impossible to optically perform the received packet signal processing executed at the node, and thus photoelectric conversion executed at the node is an essential function. On the other hand, photoelectric conversion in the hub is required due to the use of a crosspoint switch LSI in which means for realizing a dynamic network functions electrically.

  When a dynamic network is realized by a crosspoint switch LSI, an optical packet signal is converted into an electrical packet signal and input to the crosspoint switch LSI, and an electrical packet signal output from the crosspoint switch LSI is converted into an optical packet signal. Need a photoelectric converter. An optical coupling system has been disclosed in which low cost, low power consumption, and high throughput are realized by devising an interface that couples the photoelectric converter and the crosspoint switch LSI (for example, see Non-Patent Document 1). ).

  A plurality of specific means for realizing the conventional optical coupling system are known. Here, in order to clarify the operation of the dynamic network, the technology disclosed in Non-Patent Document 1 is used. An optical coupling system constructed using the above will be taken as an example. With reference to FIG. 2, the configuration and operation of this optical coupling system will be specifically described.

  FIG. 2 is a schematic block configuration diagram showing a specific example of the conventional optical coupling system disclosed in Non-Patent Document 1 using a hub configured by a dynamic network. In this optical coupling system, an interface for coupling an optical socket and a crosspoint switch LSI is realized by using PETIT (Photonic / Electronic Tied Interface). In FIG. 2, the optical signal transmission path is indicated by a thick line, and the electrical signal transmission path is indicated by a thin line. PETIT is a type of interface having a photoelectric conversion function.

  The conventional optical coupling system shown in FIG. 2 includes nodes 10 and 60, optical sockets 22 and 50, and a hub 30. FIG. 2 shows a specific configuration for only the nodes 10 and 60, but this optical coupling system shows a case where six nodes can be connected. That is, four nodes are shown as being connectable via optical sockets 52, 54, 56 and 58, and the four nodes connected via these optical sockets are not shown. is there. Although FIG. 2 shows an optical coupling system including a total of six nodes, the number of nodes is not limited to six and may be any number as long as it is three or more.

  Fig. 2 is conceptually easy to understand the connection relationship between nodes and hubs, and symbolically shows the minimum necessary components, and does not accurately reflect the implementation. Absent. In mounting, an optical coupling system is constructed by inserting a socket constituting the optical backplane so that boards constituting the nodes and the hub are substantially perpendicular to the optical backplane. In FIG. 2, such information on mounting is not shown.

  The node 10 is configured by mounting a packet signal processing circuit 14 and a photoelectric converter 18 on a printed wiring board 12. The packet signal processing circuit 14 and the photoelectric converter 18 are connected by an electric transmission line 16 formed on the printed wiring board 12. The photoelectric converter 18 and the optical socket 22 are connected by an optical transmission line 20. Similarly, the node 60 is configured by mounting a packet signal processing circuit 72 and a photoelectric converter 68 on a printed wiring board 62. The packet signal processing circuit 72 and the photoelectric converter 68 are connected by an electric transmission path 70 formed on the printed wiring board 62. The photoelectric converter 68 and the optical socket 50 are connected by an optical transmission path 64. The optical transmission path 64 generally includes both an optical transmission path for input and an optical transmission path for output.

  On the other hand, the hub 30 includes a cross-point switch LSI 40 and photoelectric converters 36, 44, 66, 74, 76, 78.

  Now, a case where a signal is sent from the node 10 to the node 60 will be described. In this case, the optical signal transmitted from the node 10 is input to the hub 30 via the optical socket 22. The optical signal input to the hub 30 propagates through the optical transmission path 32, is input to the photoelectric converter 36 via the PETIT connector 34, and is converted into an electrical signal. This electric signal propagates through the electric transmission path 38 and is input to the cross point switch LSI 40.

  The PETIT disclosed in Non-Patent Document 1 means a miniaturized optical input / output interface, and is an element for connecting an electric signal and an optical signal. That is, an element having a function of converting an electrical signal into an optical signal for connection and converting an optical signal into an electrical signal for connection. In FIG. 2, the PETIT is shown by integrating the PETIT connector and the photoelectric converter. Here, the photoelectric converter refers to both a light emitting element such as a semiconductor laser that converts an electric signal into an optical signal and a light receiving element such as a photodiode that converts an optical signal into an electric signal. That is, PETIT includes both a light emitting element and a light receiving element.

  In FIG. 2, an interface formed by integrating the PETIT connector 34 and the photoelectric converter 36 is PETIT. The PETIT connector 34 is an optical connector formed in a shape suitable for joining the photoelectric converter 36 and the optical transmission path. An interface configured by integrating the PETIT connector 46 and the photoelectric converter 44 is PETIT. Similarly, the photoelectric converters 66, 74, 76 and 78 are also photoelectric converters constituting the PETIT.

  The electrical signal input to the crosspoint switch LSI 40 is output by the crosspoint switch LSI 40 toward the transfer destination node. For example, a case where an electric signal input from the node 10 to the crosspoint switch LSI 40 is output toward the node 60 will be described. The electrical signal is usually in the form of a packet signal, and the destination node destination (in this case, the node 60) is written in the header constituting this packet signal.

  The electrical signal input from the node 10 to the crosspoint switch LSI 40 is output from the crosspoint switch LSI 40 by selecting a transmission line to be transferred to the destination by the crosspoint switch LSI 40. In this case, since the node destination of the transfer destination is the node 60, the electric signal output from the crosspoint switch LSI 40 is input to the electric transmission path 42, propagates through the electric transmission path 42, and is input to the photoelectric converter 44. The

  The electrical signal input to the photoelectric converter 44 is converted into an optical signal, and this optical signal is input to the optical transmission line 48 via the PETIT connector 46. The optical signal propagated through the optical transmission line 48 is input to the node 60 through the optical socket 50.

  The optical signal input to the node 60 propagates through the optical transmission path 64, is input to the photoelectric converter 68, and is converted into an electrical signal. This electric signal propagates through the electric transmission path 70 and is input to the packet signal processing circuit 72. In this way, communication from the node 10 to the notebook 60 is performed. Communication from the node 60 to the node 10 is also performed by following the same route, only the signal propagation direction is reversed.

  Although not shown in FIG. 2, a pair of other nodes is paired with each node of six nodes, including four nodes connected through optical sockets 52, 54, 56 and 58, respectively. The case of performing communication by connecting in the relationship of 1 is performed similarly to the communication between the node 10 and the notebook 60.

  That is, the signals transmitted from each of the six nodes in the form of optical signals are converted into signals in the form of electric signals by the photoelectric converter provided in the hub 30 and input to the crosspoint switch LSI 40. Each signal input to the crosspoint switch LSI 40 is input to a photoelectric converter connected to the selected node after selecting a transmission line connected to the destination node. For example, when the transmission destination of the signal input to the crosspoint switch LSI 40 is the node 60, the transmission line connected to the node 60 is selected and input to the photoelectric converter 44 connected to the node 60.

  In this way, when communication is performed by connecting other nodes to each of the six nodes in a one-to-one relationship, the cross-point switch LSI 40 connects the node on the transmission side and the node on the reception side. A transmission line to be connected is selected. That is, in the conventional optical coupling system shown in FIG. 2, in the connection between the nodes, the transmission line connecting the node on the transmission side and the node on the reception side that determines the combination of the nodes connected in a one-to-one relationship is selected. Is electrically executed by the crosspoint switch LSI 40. In this way, a wiring network that performs selection of a transmission line that connects a transmission-side node and a reception-side node based on a switch operation is referred to as the above-described dynamic network.

  As described above, the conventional optical coupling system shown in FIG. 2 is configured to communicate by connecting other nodes to each node in a one-to-one relationship. Therefore, in general, when the number of nodes is n, each node needs (n-1) ports to output an output signal, and (n-1) ports for inputting a signal to each node. A port is required. That is, in FIG. 2, the transmission lines for input / output signals from each node are shown as a single representative, but in reality, (n-1) transmission lines for inputting signals are shown. And 2 (n-1) transmission lines in total, including (n-1) transmission lines for outputting signals. Here, n is an integer of 3 or more.

  Therefore, in FIG. 2, each node has not one photoelectric converter, but a photoelectric converter that converts (n−1) electrical signals to optical signals and (n−1) optical signals. A photoelectric converter that converts it into an electrical signal is required. In FIG. 2, the photoelectric converter that converts an electrical signal into an optical signal and the photoelectric converter that converts an optical signal into an electrical signal are indicated as O / E without distinguishing from each other. When necessary, the photoelectric converter that converts an electrical signal into an optical signal is sometimes referred to as an E / O converter, and the photoelectric converter that converts an optical signal into an electrical signal is sometimes referred to as an O / E converter.

  A configuration that correctly reflects the above-described situation regarding the number of signal transmission lines and the number of photoelectric converters will be described with reference to FIG. FIG. 3 is a schematic block configuration diagram of a connection portion between the packet signal processing circuit 14 and the crosspoint switch LSI 40. In FIG. 3, the path of the optical signal is indicated by a thick line, and the path of the electrical signal is indicated by a thin line.

  In FIG. 3, assuming that n nodes form an optical coupling system via one hub, the packet signal processing circuit 14 included in the node 10 and the crosspoint switch LSI 40 included in the hub 30 are connected. The connection part is shown.

  The node 10 is connected to (n-1) nodes excluding the node 10, so that the packet signal processing circuit 14 transmits a transmission signal to each of the (n-1) nodes excluding the node 10. Is output in the form of electricity. That is, (n-1) electrical signal transmission lines and (n-1) O / E converters for converting (n-1) electrical signals into optical signals are required. In FIG. 3, O / E converters 24-1 to 24- (n-1) are shown.

  Further, the received signal in the form of light transmitted from each of the (n−1) nodes excluding the node 10 is input to the packet signal processing circuit 14 after being converted into a received signal in the form of electricity. In other words, (n-1) O / E converters are required to convert (n-1) optical signals in the form of light into electrical signals. In FIG. 3, E / O converters 26-1 to 26- (n-1) are shown.

  The parts indicated as photoelectric converter 18 in FIG. 2 are, as shown in FIG. 3, O / E converters 24-1 to 24- (n-1) and O / E converters 24-1 to Includes all 24- (n-1). Further, in FIG. 2, a single electric transmission line 16 is shown between the packet signal processing circuit 14 and the photoelectric converter 18, but precisely, the O / E converters 24-1 to 24- (n− (N-1) electrical signal lines connected to 1) and (n-1) electrical signal lines connected to E / O converters 26-1 to 26- (n-1) A total of 2 (n-1) electrical signal lines are included. Similarly, in FIG. 2, the optical socket 22 and the photoelectric converter 18 are shown as a single optical transmission line 20, but to be precise, the O / E converters 24-1 to 24- (n-1 ) (N-1) optical signal lines connected to the E / O converters 26-1 to 26- (n-1) and (n-1) optical signal lines connected to the E / O converters 26-1 to 26- (n-1) 2 (n-1) optical signal lines are included.

In addition, the photoelectric converter 36 includes (n-1) O / E converters and (n-1) E / O converters, and between the optical socket 22 and the photoelectric converter 36, 2 (n-1) optical transmission lines are included. Further, between the photoelectric converter 36 and the cross point switch LSI 40, 2 (n-1) electrical transmission lines are included. In FIG. 3, the electric transmission lines 16 and 38 and the optical transmission lines 20 and 32 shown in FIG. 2 mean that (n-1) bundles are bundled by an ellipse (n-1). It is shown.
Special table 2003-515785 Japanese Unexamined Patent Publication No. 2007-102013 JP 2007-104487 Ichiro Hatakeyama, et al., "A 400 Gbps Backplane Switch with 10 Gbps / port Optical I / O Interfaces", Active and Passive Optical Components for WDM Communications, V. Edited by Dutta, Achyut K .; Ohishi, Yasutake; Dutta, Niloy K .; Moerk, Jesper.Proceedings of the SPIE, Volume 6014, pp. 158-164 (2005).

  As described above, in the conventional optical coupling system described above, when information is transmitted from one node to another node via a hub, an operation of securing an information transmission circuit by an electrical switch circuit included in the hub. A net is formed. Since there is no practical optical switch in the dynamic network at present, a photoelectric converter that converts an electrical signal into an optical signal in the hub is required as shown in the conventional example described above.

  That is, in the dynamic network, an active element such as the above-described photoelectric converter or electrical switch circuit is required, and the reliability of the active element is lower than that of the passive element. For this reason, in order to ensure the reliability of the system, measures such as duplicating the same structure are usually taken, which increases the manufacturing cost of the apparatus.

  In addition, the active element is slower in operation speed than a passive element such as an optical circuit element. Therefore, even if a means for interconnecting nodes with optical signals is used to improve the transmission speed of information between nodes, there is an upper limit defined by the operating speed of active elements in the achievable transmission speed. .

  Therefore, it is conceivable to construct a static network using optical means instead of a dynamic network to overcome the transmission rate limiting condition caused by the operating speed of the active element. The static network is a network in which a transmission line connecting a transmission side node and a reception side node is determined. That is, in the static network, all combinations of the transmission side node and the reception side node are always connected by the transmission line, and it is not necessary to switch the transmission line based on the switch operation. Hereinafter, a static network configured using optical means may be referred to as an optical static network.

  There are various types of static networks, but the most powerful complete network will be described below. In a complete network, an arbitrary transmission side node is connected to all other nodes. General commentary on static networks is described, for example, in Tomita, "Parallel Computer Engineering" (Shododo, 1996, ISBN 978-4-7856-3100-0).

  When configuring an optical coupling system with an optical static network, simply remove the hub and use optical fibers or optical waveguides in the optical backplane to connect each node of multiple nodes to other nodes. If a static network that is independently connected in a one-to-one relationship is formed, the problems associated with using the dynamic network described above are eliminated. However, this method of constructing a static network on the optical backplane requires a very complicated arrangement of optical transmission lines to connect multiple nodes independently in a one-to-one relationship. It is difficult to realize.

  For example, in order to configure a static network on the optical backplane, it is necessary to arrange a complicated optical transmission line while avoiding a large number of electrical connectors or optical connectors installed on the optical backplane. Such a configuration becomes very difficult to implement as the number of nodes increases because the number of optical transmission lines increases in proportion to the number of nodes.

  Accordingly, an object of the present invention is to easily form an optical static network in which each node of a plurality of nodes is independently connected to other nodes in a one-to-one relationship. To provide a system.

  The inventor of the present invention has convinced that the above problem can be solved by configuring a static network in the hub instead of configuring a static network in the optical backplane. That is, if a static network is configured in the hub, it is not necessary to make any changes to the installation form of the optical transmission path installed on the optical backplane.

  In addition, if a flexible optical fiber wiring board specified by the JPCA (Japan Printed Circuit Association) standard by the Japan Printed Circuit Industry Association is used as appropriate, a static network suitable for the optical coupling system of the present invention is configured as a hub. I was convinced that it could be installed on the printed wiring board. Details of the JPCA standard are described in “Wiring Design Guidance for Flexible Optical Wiring Boards Using Quartz-Based Optical Fibers” (issued in 2005) published by Japan Printed Circuit Industries Association.

  According to the gist of the present invention based on the above philosophy, an optical coupling system having the following configuration is provided.

  The optical coupling system according to the present invention includes a plurality of nodes, a hub, and an optical backplane. The hub connects each node of the plurality of nodes independently to each other in a one-to-one relationship. It is characterized by having a static net. The optical backplane has an optical transmission line connecting a plurality of nodes and a hub. A node refers to an electric circuit subsystem that is a unit for transmitting information. A hub refers to a subsystem that mediates communication between nodes.

  There are various types of static networks as described above, and the most powerful static network among them is the complete network. In the optical coupling system of the present invention, not only a complete network is adopted as a static network but also a static network other than a complete network can be applied. Whether or not the static network is configured as a complete network depends on the communication form used in the optical coupling system of the present invention, and is a design matter that depends on the configuration of the packet signal used in the optical coupling system of the present invention. is there. Therefore, the static network provided in the optical coupling system of the present invention is not necessarily configured as a complete network, and can be configured as a static network excluding the complete network. In this case, the optical coupling system of the present invention is configured to be able to transfer a plurality of packet signals between nodes corresponding to the destination written in the header of the packet signal used for communication between nodes. .

  The static network is preferably constructed using an optical wiring board. The optical wiring board is formed by wiring and fixing optical fibers on a flexible sheet or substrate with a wiring pattern for independently connecting them in a one-to-one relationship, and providing a protective film thereon. A flexible optical fiber wiring board is preferable.

  Also, an optical input / output terminal that joins the input / output end of the node and the input / output end of the optical transmission line, and an optical input / output terminal that joins the input / output end of the optical wiring board and the input / output end of the optical transmission line Is preferably an MT connector (Mechanically Transferable Connector). Hereinafter, the input / output terminal is sometimes used to mean a connector having a connection function between an input terminal and an output terminal. When an optical input / output terminal is meant to include a connection function, it is sometimes called an optical connector. Further, when an optical connector is regarded as an element having a specific shape on mounting, it may be called an optical socket.

  The hub is coupled to all nodes by electrical signals, and preferably has a management system that performs initial setting at power-on, system failure processing, and temperature control processing of the hub.

  In the optical coupling system of the present invention, since the hub constituting the system includes a static network, it is not necessary to change the form of the optical transmission path installed on the optical backplane. That is, since it is not necessary to form a static network on the optical backplane, the optical backplane may simply have a plurality of optical transmission lines such as optical fibers or optical waveguides arranged in parallel.

  Therefore, when the number of nodes is n, 2 (n−1) optical waveguides are required as described above, but these optical transmission lines may simply be arranged parallel to each other. Therefore, an optical transmission line can be easily arranged on an optical backplane simply by arranging a normal flat optical fiber cable, for example, which is composed of 2 (n-1) optical fibers arranged in parallel. Is possible. Hereinafter, a flat optical fiber cable configured by arranging a plurality of optical fibers in parallel may be referred to as an optical fiber plate.

  Further, in order to install the static network on the printed wiring board constituting the hub, a space necessary for installing the static network on the printed wiring board may be secured. It is possible to secure a space necessary for installing the static network on the printed wiring board constituting the hub without causing any trouble in design. In other words, a static wiring network that has a function of independently connecting each node of a plurality of nodes to other nodes in a one-to-one relationship, which is required in an optical coupling system, is a printed wiring board that constitutes a hub. It can be easily formed on top.

  A flexible optical fiber wiring board can be used as the optical wiring board. If a flexible optical fiber wiring board specified by the JPCA standard is used as appropriate, an optical coupling system can be realized using standard components. Is possible. As a result, it is possible to easily unify the components of the optical coupling system, thereby contributing to a reduction in manufacturing cost, and the industrial utility value of the optical coupling system is increased.

  An optical input / output terminal that joins the input / output end of the node and the input / output end of the optical transmission line, and an optical input / output terminal that joins the input / output end of the optical wiring board and the input / output end of the optical transmission line, By using the MT connector that has already become a unified standard in this industry, it is possible to enjoy the benefits of unifying the components of the optical coupling system, like the above-mentioned flexible optical fiber wiring board.

  In addition, since the hub has the above-described management system, it is possible to realize an excellent optical coupling system that can perform initial setting at power-on, system failure processing, and temperature control processing of the hub. Become.

  Hereinafter, an embodiment of the present invention will be described with reference to FIGS. Each drawing schematically shows each component so that the present invention can be understood, and the present invention is not limited to the illustrated examples. In addition, in the drawings including FIGS. 1 to 3 described above, the same components are denoted by the same reference numerals, and redundant description of these functions may be omitted. In the following FIGS. 4 to 8, the path of the optical signal is indicated by a thick line, and the path of the electric signal is indicated by a thin line.

<Optical coupling system>
With reference to FIG. 4, an outline of the basic configuration and operation of the optical coupling system according to the embodiment of the present invention will be described. FIG. 4 is a schematic block diagram of the optical coupling system according to the embodiment of the present invention. In FIG. 4, the connection between the elements provided in the block is not shown.

  The optical coupling system according to the embodiment of the present invention includes a plurality of nodes such as a node 110 and a node 112, a hub 130, and an optical backplane 80. The hub 130 includes a static network 132 that connects each node of a plurality of nodes independently to each other in a one-to-one relationship. The optical backplane 80 has an optical transmission path that connects a plurality of nodes such as the nodes 110 and 112 and the hub 130.

  In other words, the node 110 and the node 112 of the optical coupling system according to the embodiment of the present invention will be described. The node 110 and the node 112 are coupled via the hub 130. The static network 132 is configured by an optical wiring board such as a flexible optical fiber wiring board. Further, similarly to the conventional optical coupling system described with reference to FIG. 1, the node includes a packet signal processing circuit that processes a transmission packet signal that is a transmission signal and a reception packet signal that is a reception signal, and a photoelectric converter. It has. That is, the node 110 includes a packet signal processing circuit 110-1 and a photoelectric converter 110-2, and the node 112 includes a packet signal processing circuit 112-1 and a photoelectric converter 112-2. In the configuration example shown in FIG. 4, the node 110 and the node 112 are shown as representatives via the hub 130. However, if there are three or more nodes, it is only necessary to provide the necessary number according to the design. This is the same as the conventional optical coupling system shown in the description with reference to FIG.

  A signal transmitted from the node 110 to the node 112 is output to the transmission line output to the node 112 via the static network 132 included in the hub 130, and input to the node 112 via the optical backplane 80. Is done. In this way, communication from the node 110 to the node 112 is performed.

  Next, with reference to FIG. 5, an embodiment in which the optical coupling system of the present invention is embodied will be described. FIG. 5 is a schematic block diagram of the optical coupling system according to the embodiment of the present invention.

  The optical coupling system according to the embodiment of the present invention includes a plurality of nodes such as a node 110, a node 112, and a node 114, a hub 130, and a backplane 100, and the hub 130 includes each node of the plurality of nodes. A static network 132 and a management system 134 are connected independently to each other node in a one-to-one relationship.

  The backplane 100 includes a power supply wiring backplane 102, an electrical backplane 104, and an optical backplane 106.

  The management system 134 provided with the hub 130 is electrically connected to a plurality of nodes such as the node 110, the node 112, and the node 114 via the electric backplane 104, and the initial setting at the time of power-on and the system failure Processing and temperature control processing of the hub are performed. The static network 132 has a function of independently connecting a plurality of nodes such as the node 110, the node 112, and the node 114 in a one-to-one relationship. The static network 132 and a plurality of nodes such as the node 110, the node 112, and the node 114 are individually optically connected via the optical backplane 106.

  A 10 gigabit Ethernet packet is input / output from the external network 200 to a plurality of nodes such as the node 110, the node 112, and the node 114. Ethernet is a registered trademark of Fuji Xerox Co., Ltd., and is one of computer network standards standardized by the IEEE 802.3 committee.

  In a plurality of nodes such as the node 110, the node 112, and the node 114, the optical packet signal in the form of an optical signal is converted into an electrical packet signal in the form of an electrical signal, and is indicated in the header of the electrical packet signal. Depending on the destination address, a packet to be processed by the node is subjected to predetermined processing by an information processing circuit (not shown) included in the node and received. When the destination address indicated in the header of the electrical signal is another node, an output port to the node specified by the address is selected and transmitted to the node. In this case, the electrical packet signal is converted into an optical packet signal and then transmitted to the node via the optical backplane 106.

  The power source 120 illustrated in FIG. 5 supplies power to a plurality of nodes such as the node 110, the node 112, and the node 114 via the power wiring backplane 102. The power supplied from the power source 120 is directly supplied to the management system 134 provided in the hub 130, and is used for initial setting when the power is turned on, system failure processing, and temperature control processing of the hub.

  As described above, the power supply wiring backplane 102 and the electrical backplane 104 included in the backplane 100 of the optical coupling system shown in FIG. 5 are the same as those in the conventional optical coupling system.

<Connection between optical backplane and node>
The connection between the optical backplane and the node will be described with reference to FIG. FIG. 6 is a schematic block diagram for explaining the connection between the optical backplane and the node. In FIG. 6, the node 110 is shown as an example, but the other nodes have the same configuration. In FIG. 6, it is assumed that the number of nodes connected to the optical backplane is four. Therefore, three optical transmission lines are required for sending optical packet signals from the node 110 to the optical backplane 106, and there are optical transmission paths for sending optical packet signals from the optical backplane 106 to the node 110. Since three are required, a total of six optical transmission lines are required between the optical backplane 106 and the node 110.

  The node 110 receives the packet signal from the external network 200, processes the packet signal, generates an optical packet signal output from the node 110, and outputs the packet signal to the backplane 100. Section 140, a parallel / serial converter (P / S converter) 142, and an E / O converter 144. The P / S converter 142 converts the parallelized parallel signal output from the received packet signal processing unit 140 into a serial signal. The E / O converter 144 converts the serial signal output from the P / S converter 142 into an optical packet signal. Although six electric transmission paths for transmitting electric packet signals from the received packet signal processing unit 140 to the P / S converter 142 are shown, this is not limited to six, and there are three electric transmission lines other than the node 110. In the case of an optical coupling system comprising nodes, the number is a multiple of 3.

  That is, the number of serial signals output from the P / S converter 142 is equal to (n−1), where n is the number of nodes included in the optical coupling system. If the ratio of the number of parallel signals input to the P / S converter 142 and the number of serial signals output from the P / S converter 142 is called the parallel number, the parallel number is one serial signal. Indicates how many parallel signals are generated by P / S conversion. The parallel number is usually in byte units, that is, 8 or 16.

  From the P / S converter 142, an optical packet signal (serial signal) to be transmitted to three nodes other than the node 110 is generated and output. In FIG. 6, this is shown by three upward straight lines with an arrow from the node 110 to the tip.

  In addition, the node 110 processes a packet signal received from the backplane 100 and transmits the packet signal to the external network 200, so that a transmission packet signal processing unit 150, a serial / parallel converter (S / P converter) 152 , And an O / E converter 154. The O / E converter 154 converts the optical packet signal that is propagated through the optical backplane 106 and input to the node 110 into an electrical packet signal and outputs the electrical packet signal. The S / P converter 154 converts the electric packet signal (serial signal) output from the O / E converter 154 into an electric packet signal (parallel signal). The electric packet signal output from the S / P converter 154 is input to the transmission packet signal processing unit 150, and the packet to be processed by the node 110 according to the destination address indicated in the header of the electric packet signal And electrical packet signals to be transmitted to other nodes are identified and processed.

  Although six electric transmission paths for transmitting electric packet signals input from the S / P converter 152 to the transmission packet signal processing unit 150 are shown, it is described above that the number is not limited to six. This is the same as that the number of electrical transmission lines for transmitting electrical packet signals to the P / S converter 142 is not limited to six. Since one byte is 8 bits, in many cases, when the number of nodes is four, for example, there are 24 lines (== any one node connecting to the other three nodes except this node) 8 × 3). In FIG. 6, six electric transmission paths for transmitting electric packet signals are shown in a simplified manner including six electric transmission lines. However, as described above, the number is 24, etc., and the number is usually larger. .

  From the external network 200, independent optical packet signals respectively transmitted from three nodes other than the node 110 are input to the O / E converters 164, 172, and 180, respectively, and are converted into electric packet signals. The signals are converted into parallel signals by the / P converters 162, 170 and 178 and output. The parallel signals output from the S / P converters 162, 170, and 178 are input to the received packet signal processing unit 140.

  Further, the transmission packet signal processing unit 150 outputs three independent electric parallel signals to be transmitted to three nodes other than the node 110. The three independent electric parallel signals output from the transmission packet signal processing unit 150 are input to the P / S converters 166, 174, and 182 respectively, converted into electric serial signals, and output. The electrical serial signals output from the P / S converters 166, 174, and 182 are input to the E / O converters 168, 176, and 184, respectively, and are converted into optical serial signals, that is, optical packet signals. Is input.

  FIG. 6 shows an example of the configuration of the connection between the node 110 and the backplane 100 and the specific configuration of the node 110, but the same applies to the nodes 112 and 114 shown in FIG.

  The P / S converter 142 included in the node 110 converts the parallelized parallel signal output from the received packet signal processing unit 140 into a serial signal. The E / O converter 144 converts the serial signal output from the P / S converter 142 into an optical packet signal.

  Further, the P / S converter 142 generates and outputs an optical packet signal to be transmitted to three nodes other than the node 110. In FIG. 6, this is shown by three upward straight lines with an arrow from the node 110 to the tip.

  An electrical signal for electrically controlling the reception packet signal processing unit 140 and the transmission packet signal processing unit 150 is supplied via an electrical backplane 104 included in the backplane 100. The packet signal processing circuit 110-1 included in the node 110 illustrated in FIG. 4 includes the reception packet signal processing unit 140, the transmission packet signal processing unit 150, the plurality of P / S converters, and the plurality of S / S illustrated in FIG. It corresponds to a packet signal processing circuit that integrates elements such as a P converter. Also, the photoelectric converter 110-2 illustrated in FIG. 4 corresponds to a plurality of photoelectric converters such as the E / O converter 144 and the O / E converter 150.

  The node 110 and the backplane 100 are optically and electrically connected by optical sockets 146 and 156 and electrical sockets 158 and 160. In FIG. 6, these sockets are simplified so that they are provided only in the node 110, but the same kind of sockets are also provided on the backplane 100 side to be engaged with and joined to these sockets. ing.

  The power for driving the reception packet signal processing unit 140, the transmission packet signal processing unit 150, the plurality of P / S converters, and the plurality of S / P converters is supplied from the power source 120 illustrated in FIG. 100 is supplied via a power wiring backplane 102 and an electrical socket 160. In FIG. 6, the electrical wiring connected from the electrical socket 160 to the inside of the node 110 is not an essential part of the present invention, and is not shown.

  In FIG. 6, an optical transmission path for transmitting an optical packet signal output from the node 110 is conceptually indicated by a straight line with an arrow at the tip of a thick line. In the mounting, the optical packet signal output from the node 110 is connected by the optical socket provided in the node 110 and the backplane 100, and is input to the optical transmission line wired to the optical backplane 106. ing. Since the configuration on this part is the same as that of the conventional optical coupling system, it is obvious to those skilled in the art.

  The optical socket 146 is an optical socket for connecting an optical transmission line for outputting an optical packet signal output from the node 110 to the optical backplane 106. In FIG. 6, there are three optical transmission lines, but the number is not essential and belongs to the design matter of the optical coupling system. That is, in FIG. 6, since the number of nodes connected via the backplane 100 is set to four, three optical transmission lines connected to the other three nodes other than the node 110 are three. It just shows that it is necessary. In general, when the number of nodes connected via the backplane 100 is n, the number of optical transmission lines is (n−1).

  According to a preferred embodiment of the present invention, each node of the plurality of nodes is separated by the static network 132 provided in the hub 130 shown in FIG. 5 through the optical sockets 146 and 156 and the optical backplane 106. It is preferable to connect the nodes independently in a one-to-one relationship. Therefore, with reference to FIG. 7, first, how the optical transmission line provided in the optical backplane 106, the hub 130, and the connection terminals of the plurality of nodes are connected will be described.

<Connection by optical backplane>
With reference to FIG. 7, a connection configuration between the connection terminals of the hub 130 and the plurality of nodes described above and an optical transmission line provided in the optical backplane 106 will be described. FIG. 7 is a schematic diagram showing a form of connection between a connection terminal of a hub constituted by the optical static network of the present invention and a connection terminal provided in each of the four nodes by an optical fiber plate constituting an optical backplane. FIG. The optical fiber plate can be used by appropriately selecting from optical wiring boards manufactured according to JPCA-PE02, which is a JPCA standard.

  In FIG. 7, in the optical coupling system configured by connecting the four nodes N1 to N4 to the hub 130, the optical sockets provided by the hub 130 and the four nodes N1 to N4, respectively. The relationship with the optical waveguide formed in the optical backplane connecting these optical sockets is shown. An optical waveguide formed on the optical backplane is indicated by a thick line, and a signal transmission direction is indicated by a thick line, and the end of the optical waveguide is indicated by an arrow. Here, the description will be made assuming that the optical waveguide formed on the optical backplane is formed of an optical fiber plate.

  Since the number of nodes is 4, three optical transmission lines for signals from the hub 130 to each node are required. Also, three optical transmission paths for signals from each node to the hub 130 are required. Accordingly, the number of optical transmission lines included in the optical fiber plate connecting the hub 130 and each node is required to be six. Accordingly, in FIG. 7, six optical transmission lines connecting the hub 130 and each node are shown. In general, when the number of nodes is n, the number of optical transmission lines included in the optical fiber plate connecting the hub 130 and each node is 2 (n-1).

  The hub 130 includes four optical connectors, optical connectors HUA, HDA, HUB, and HDB. The optical connector HUA is an optical connector having an input end having a port number of 1 to 3 and an output end having a port number of 4 to 6, and the optical connector HDA is an input end and a port number having a port number of 1 to 3. The optical connector HUB is an optical connector having an input end with a port number of 7-9 and an output end with a port number of 10-12. The connector HDB is an optical connector having an input end with a port number of 7-9 and an output end with a port number of 10-12.

  Node N1 and hub 130 are optically coupled by optical fiber plate 190, node N2 and hub 130 are optically coupled by optical fiber plate 192, and node N3 and hub 130 are optically coupled by optical fiber plate 194. The node N4 and the hub 130 are optically coupled by an optical fiber plate 196. The optical fiber plates 190, 192, 194 and 196 are installed on the optical backplane 106.

  FIG. 7 shows a case where the hub 130 includes four connectors of optical connectors HUA, HDA, HUB, and HDB for convenience of explanation, but the present invention is not limited to this. For example, an optical connector HA having an input end with a port number of 1-6 and an output end with a port number of 7-12, and an input end with a port number of 1-6 and a port number of 7-12 A configuration including an optical connector HB having an output end is also possible. It is a matter of design to determine the number of optical connectors having input / output terminals.

  As the four optical connectors shown in FIG. 7, which are optical connectors HUA, HDA, HUB, and HDB, MT connectors can be used as appropriate. In addition, it is possible to appropriately select and use the optical connector manufactured according to JPCA-PE03-01, which is the JPCA standard.

In FIG. 7, the hub 130 is surrounded by a broken-line rectangle, and only the port numbers are shown in the broken-line rectangle, which are the optical connector identification symbols HUA, HDA, HUB, and HDB. An optical static network that is an optical transmission line connecting the ports of HUA, HDA, HUB, and HDB is not shown. An embodiment of this optical static network will be described next.
<Optical static network>
With reference to FIG. 8, an exemplary embodiment of an optical static network suitable for use in the optical coupling system of the present invention will be described. FIG. 8 is a schematic configuration diagram of a static network suitable for use in the optical coupling system of the present invention.

  In FIG. 8, the existence of the hub 130 and the static net 132 is indicated by a broken-line rectangle. As described above, the hub 130 includes four optical connectors, that is, optical connectors HUA, HDA, HUB, and HDB, and each optical connector includes three input ports and three output ports. In FIG. 8, the optical connector of node N1 having three input ports and three output ports is denoted N1 for simplicity.

  As described above, ports 1 to 3 of N1 are output ports, and ports 4 to 6 are input ports. Similarly, the optical connector of the node N2 is indicated as N2, and the ports 1-3 of N2 are output ports and the ports 4-6 are input ports. The optical connector of the node N3 is indicated as N3, the ports 1 to 3 of the N3 are output ports, and the ports 4 to 6 are input ports. The optical connector of the node N4 is indicated as N4, the ports 1 to 3 of the N4 are output ports, and the ports 4 to 6 are input ports.

  Also, each of the four optical connectors, optical connectors HUA, HDA, HUB, and HDB, is coupled to an optical connector including nodes N2, N1, N3, and N4 via an optical transmission line. Ports 1 to 3 of the optical connector HUA are input ports, and ports 4 to 6 are output ports. Ports 1 to 3 of the optical connector HDA are input ports, and ports 4 to 6 are output ports. Ports 7-9 of the optical connector HUB are input ports, and ports 10-12 are output ports. Ports 7 to 9 of the optical connector HDB are input ports, and ports 10 to 12 are output ports.

  In FIG. 8, the input ports of the optical connectors HUA, HUB, HDA, and HDB are indicated by solid squares and the output ports are indicated by squares by broken lines. FIG. 7 shows between the optical connector N1 and the optical connector HDA, between the optical connector N2 and the optical connector HUA, between the optical connector N3 and the optical connector HUB, and between the optical connector N4 and the optical connector HDB. As shown, the optical transmission lines are coupled by optical transmission lines each comprising an optical pack plane. For the sake of simplicity, these optical transmission lines are not shown in FIG.

  In FIG. 8, the optical transmission line is indicated by a thick line, and the signal transmission direction is indicated by an arrow at the end of the optical transmission line indicated by the bold line. The connection pattern shown in FIG. 8 is merely an example, and is not limited to this connection pattern. When the total number of nodes connected via the static network is n, (n-1) output ports and input ports are required for each node. Any connection pattern can be used as long as all output ports included in each node satisfy the condition that they are independently connected in a one-to-one relationship to any one of the nodes other than the node. It may be formed.

  For example, in an optical coupling system configured with n nodes, when these nodes are N1 to Nn, the (n−1) output ports included in the node N1 are excluded from the node N1, One of the (n−1) input ports that node N2 has, and one of the (n−1) input ports that node N3 has. It is connected to one of the (n−1) input ports provided by the node Nn. The (n−1) output ports included in the node N2 include one input port among the (n−1) input ports included in the node N1 and the node N3 except for the node N2. It is connected to one input port of the (n−1) input ports, and one input port of the (n−1) input ports provided with the node Nn. The same applies to the (n−1) output ports provided by the nodes N3 to Nn.

  In determining the connection pattern, it is preferable to arrange the optical transmission lines so that three or more optical transmission lines do not intersect at the same position at the point where the optical transmission lines intersect each other.

  This is because when three or more optical transmission lines intersect at the same position, the laminated thickness for overlapping the optical transmission lines increases at this intersection, and the bending radius of curvature of the optical transmission line is increased in the vicinity of this intersection. Need to be reduced. It is desirable to bend the optical transmission line so that the radius of curvature is as large as possible in order to keep the magnitude of optical loss small and to reduce the magnitude of stress applied to the optical waveguide. Therefore, it is desirable not to adopt a wiring configuration in which three or more optical transmission paths intersect at one point, so that the optical transmission path must be bent with a reduced radius of curvature.

  In order to form the static net 132, it is possible to use an optical wiring board formed in a laminated structure with a flexible sheet such as a polymer film or an optical fiber on a substrate interposed therebetween. As the optical wiring board, it is possible to appropriately select and use an optical wiring board manufactured according to JPCA-PE02-01 which is a JPCA standard. In the optical wiring board manufactured as defined in JPCA-PE02-01, the optical fiber is wired and fixed on a flexible sheet or substrate in a one-to-one relationship independently, and fixed. There is a flexible optical fiber wiring board formed by providing a protective film thereon. By sticking this flexible optical fiber wiring board to the wiring board of the hub 130, a suitable static network can be formed using the optical coupling system of the present invention.

1 is a schematic block configuration diagram of a conventional optical coupling system using a hub configured by a dynamic network. FIG. It is a schematic block block diagram which shows the specific example of the conventional optical coupling system using the hub comprised by a dynamic network. FIG. 3 is a schematic block configuration diagram of a connection portion between a packet signal processing circuit and a crosspoint switch LSI. 1 is a schematic block diagram of an optical coupling system according to an embodiment of the present invention. It is a schematic block diagram of the Example of the optical coupling system of this invention. FIG. 3 is a schematic block configuration diagram for explaining connection between an optical backplane and a node. It is a schematic block diagram which shows the connection form of the connection terminal of the hub comprised by the static network of this invention, and each connection terminal of four nodes by the optical fiber plate which comprises an optical backplane. It is a schematic block diagram of a static network suitable for use in the optical coupling system of the present invention.

Explanation of symbols

10, 60, 110, 112, 114: Node
10-1, 14, 60-1, 72, 110-1, 112-1: Packet signal processing circuit
10-2, 18, 30-2, 36, 44, 60-2, 66, 68, 74, 76, 78, 110-2, 112-2: Photoelectric converter
12, 62: Printed circuit board
16, 38, 42, 70: Electric transmission line
20, 32, 48, 64: Optical transmission line
22, 50, 52, 54, 56, 58, 146, 156: Optical socket
24-1, 24- (n-1), 84-1, 84- (n-1), 154, 164, 172, 180: O / E converter
26-1, 26- (n-1), 82-1, 82- (n-1), 144, 168, 176, 184: E / O converter
30, 130: Hub
30-1: Dynamic network
34, 46: PETIT connector
40: Crosspoint switch LSI
80, 106: Optical backplane
100: Backplane
102: Power supply wiring backplane
104: Electric backplane
120: Power supply
132: Static network
134: Management system
140: Received packet signal processor
142, 166, 174, 182: P / S converter
150: Transmission packet signal processor
152, 162, 170, 178: S / P converter
158, 160: Electrical socket
190, 192, 194, 196: Optical fiber plate
200: External network

Claims (6)

A plurality of nodes (Nodes), which are electrical circuit subsystems that are units of information transmission,
A hub that is a subsystem that mediates communication between the nodes; and
Comprising an optical backplane having an optical transmission line connecting the plurality of nodes and the hub;
The hub includes a static network that connects each node of the plurality of nodes independently to each other in a one-to-one relationship.   2. The optical coupling system according to claim 1, wherein the static network is configured using an optical wiring board.   The optical wiring board is formed by wiring and fixing an optical fiber on a flexible sheet or substrate with a wiring pattern for independently connecting in a one-to-one relationship, and providing a protective film thereon. 3. The optical coupling system according to claim 2, wherein the optical coupling system is a flexible optical fiber wiring board.   An optical input / output terminal that joins the input / output end of the node and the input / output end of the optical transmission line, and an optical input that joins the input / output end of the optical wiring board and the input / output end of the optical transmission line. 4. The optical coupling system according to claim 2, wherein the output terminal is an MT connector (Mechanically Transferable Connector).   The hub has a management system, and the management system is coupled to all of the nodes by electric signals, and performs initial setting at power-on, system failure processing, and temperature control processing of the hub. The optical coupling system according to any one of claims 1 to 4.   The static network is a static network excluding a complete network, and the packet signal is transmitted between the plurality of nodes corresponding to a destination written in a header of a packet signal used for communication between the nodes. 6. The optical coupling system according to claim 1, wherein the optical coupling system is configured to be able to transfer.

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