JPH06252936A - Distribution/collection system for control information - Google Patents

Abstract

PURPOSE:To provide a means with which a distribution network having a shape like tree branches can be self-controlled in a reference signal distribution system where the higher-order nodes branch out to the lower-order nodes in a network of a hierarchical structure. CONSTITUTION:On the routes led from the higher-order nodes to the lower-order nodes, each node transmits its own information and the node information given from the higher-order nodes to the lower-order nodes after adding these information to a reference signal. On the routes led from the lower-order nodes to the higher-order nodes, each node transmits its own information to the higher- order nodes in addition to the node information given from the lower-order nodes.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to management of a distribution network for distributing reference signals such as clock and time in a digital communication network.

[0002]

2. Description of the Related Art In a conventional distribution network such as a clock in a digital communication network, an optimum transmission path between nodes is selected and a reference signal is transmitted from an upper node, and the reference signal is transmitted from a lower node side (reception side). The distribution network was managed by confirming that it was received normally. FIG. 7 is a diagram for explaining a conventional clock distribution network, in which 101 is an upper node, 102 is a lower node, 103 is a transmission line, and 10
Reference numerals 4 and 105 represent terminal devices, and reference numerals 106 and 107 represent reference signal generators. As shown in FIG.
The reference signal sent from 1 is transferred as the basic clock component of the transmission path 103 set between the nodes.
The lower node (reception side) 102 extracts an existing clock component from the transmission path 103 and generates a reference signal.

In the conventional system as shown in the figure, when the transmission line is switched due to a failure or the like and a signal is received from a device which operates with a clock generated by a source other than the reference signal source, the receiving side receives a clock other than the reference signal. Extract the ingredients.

Further, when the distribution network structure from the upper node to the lower node is switched, it cannot be determined from which node the reference signal is transferred by only extracting the clock component. When there is a restriction on the node connection configuration and the connection configuration is changed by switching, the node connection configuration must be grasped by another network management device.

FIG. 8 is a diagram for explaining a change in network configuration due to switching. In the figure, the route indicated by in the system operated in the configuration as shown in (a) becomes a failure,
This indicates that the switching has been performed as shown in FIG. That is, the connection of the node 108 → route → node 109 → route → node 110 initially changed to node 108 → route → node 111 → route → node 109 → route → node 110. . However, at this time, the node 110 cannot recognize that the route has changed in this way.

[0006]

DISCLOSURE OF THE INVENTION The digital communication network as described above has been expanded with the expansion of the network.
The number of nodes increases. The optimum transmission path set when a node is newly installed is often changed from the initial setting due to switching at the time of transmission path failure or change due to the state of the transmission path. In such a case, in order to manage the connection state of the distribution network, it is necessary to rely on the management system of the transmission line network.

Further, due to the expansion of the network, various signal sources exist from the upper node to the lowermost node, and even if the transmission line in the middle is disconnected,
There is a possibility that a pseudo signal may be mistaken for a reference signal in a lower node.

The present invention has been made to solve such a conventional unfavorable problem, and a dendritic distribution network can automatically manage itself by using a bidirectional transmission line. The purpose is to provide such means.

[0009]

According to the invention, the above-mentioned problems are solved by the means recited in the claims.

That is, the present invention has a hierarchical structure in which a plurality of nodes are connected and the upper node and the lower node are connected by a bidirectional signal transmission transmission path.
The upper node transmits the reference signal to at least one lower node using the bidirectional signal transmission transmission line, and the lower node reproduces the reference signal and then transmits it as a reference signal to the lower node again. In the dendritic reference signal distribution system, a means for adding node information to the reference signal and transmitting it is provided, and when the node is the highest node in the route from the node to the lower node, Information is added to the reference signal and transmitted, and when the node is an intermediate node, the node information sent from the upper node is further added with the information of its own node and added to the reference signal. In the route from the lower node to the upper node, when the node is the lowest node, the information of its own node is transmitted and the node is an intermediate node. In some case, the integration of the node information sent from the lower node, to the node information, further, a management information distribution collection method characterized by sending by adding the information of the own node.

[0011]

According to the present invention, node information can be transferred between nodes, and it is possible to collect / distribute node information not only between adjacent nodes but also for all nodes. Then, the upper node side can grasp the status of the reference signal in the lower node, and further grasp the network configuration of the entire distribution network. On the lower node side, the distribution network configuration of the transmitted reference signal can be traced, and information such as the originator, state, and accuracy of the reference signal can be obtained.

[0012]

FIG. 1 is a diagram showing an example of a network configuration for implementing the present invention. Hereinafter, a case where a time signal is distributed from an upper node to a lower node as a reference signal and management information related thereto is distributed / collected will be described with reference to FIG. In the example of FIG. 1, the time signal is distributed among the five nodes. The time signal is distributed from the master node 1 located at the top of the hierarchical structure to the other slave nodes 2, 3, 4, 5 by the bidirectional transmission paths 6, 7, 8, 9 set between the nodes. It At the same time, the node information of each node is distributed / collected by this bidirectional transmission.

FIG. 2 is a diagram showing a signal flow between two nodes. In the figure, the reference signal processing device 12 of the node A10 distributes the reference signal to the reference signal processing device 13 of the node B11. At this time, the node information is supplied to the node processing device 14 of the node A10 and the node of the node B11. Transmission / reception is performed between the processing devices 15. That is, node A
The reference signal 16 of 10 and the node information 17 are combined by the signal combining device 20 and then transmitted to the signal separating device 21 of the node B 11 by using the forward transmission path 24 between the terminal devices 22 and 23. The signal 18 and the node information 19 are separated. Conversely, the reference signal 25 of the node B11 and the node information 2
6 is synthesized by the signal synthesizer 29, and the terminal station devices 22, 2 are combined.
The signal is transmitted to the signal separation device 30 of the node A10 using the return transmission line 31 via 3 and separated into the reference signal 27 and the node information 28.

The node information processing devices 14 and 15 have several input / output ports as shown in FIG. One is an input / output port 50 with an upper node, and this is limited to one.

The other is an input / output port 51 to / from a lower node, which is present by the number of nodes receiving the reference signal from this node. By using these ports, the node information processing devices 14 and 15 realize two types of functions. One is an information distribution function that uses the node information from the upper node in its own node, adds its own node information, and distributes the node information to the lower nodes. It is an information gathering function that gathers the received node information, uses it in its own node, adds its own node information, and transfers it to the upper node.

FIG. 4 is an example of node information distributed from the upper node to the lower node. The information included in the node information string is the node name here. Every time the node information from the upper node is processed by the node information processing device, the node name of the processed node is added to the node information. In this example, the node information of the slave node n is shown.

Slave node n-1 as shown in FIG.
The node information up to is received, and as shown in FIG. 4B, the node name slave node n of its own is added and the node information is transmitted. By such information transfer, each node can confirm which node the reference signal is passing through before being distributed to its own node. Further, by tracing the distribution route which is important in the subordinate synchronous network as shown in FIG. 1, it is possible to confirm that the loop is not formed and that the route always returns to the master node.

In the example of the network configuration shown in FIG. 1, this is based on the node information distributed by the slave node 4 via the transmission path 8 to the slave node 2 corresponding to the upper node of the slave node 4 and the master node 1. Means that it is possible to confirm that the reference signal is passing. Also,
By adding the state of the upper node and the accuracy of the reference signal to the node information, it becomes possible for the lower node to manage the transmitted reference signal more accurately.

FIG. 5 shows an example of connection of slave nodes when node information is accumulated from lower nodes using a return transmission line. This figure shows a case where m slave nodes from slave node n + 1 to slave node n + m send node information to slave node n corresponding to these upper nodes. The slave nodes from the slave nodes n + 1 to n + m corresponding to the lower nodes send the node information as shown in FIGS. 6A, 6B, and 6C to the slave node n. Are multiplexed and sent to a higher node.

The information contained in the node information string is the node name here. By sequentially transferring the node information from the lower node to the upper node by such a procedure, even if the transfer route of the reference signal is changed due to the switching due to the failure of the transmission line, the upper node that is the distribution source of the reference signal You can always check the distribution route with. Further, if the lower node adds the node state and the accuracy of the reference signal to the node information, the upper node can grasp the state of the lower node.

[0021]

As described above, according to the present invention,
By using a bidirectional transmission path set for the purpose of transferring a reference signal, node information can be passed between nodes, and node information for all nodes is collected / distributed not only between adjacent nodes. be able to. Therefore, it is possible to manage the network independently of the reference signal distribution network without relying on another management system, and it is easy to realize a highly reliable reference signal distribution system with excellent maintainability and operability. There are advantages.

[Brief description of drawings]

FIG. 1 is a diagram showing an example of a network configuration for implementing the present invention.

FIG. 2 is a diagram showing a signal flow between nodes.

FIG. 3 is a diagram illustrating a node information processing device.

FIG. 4 is a diagram showing an example of node information.

FIG. 5 is a diagram illustrating an example of connection of slave nodes.

FIG. 6 is a diagram showing an example of node information.

FIG. 7 is a diagram illustrating a conventional clock distribution network.

FIG. 8 is a diagram illustrating a change in network configuration due to switching.

[Explanation of symbols]

 1 master node 2-5 slave node 6-9 bidirectional transmission line 10 node A 11 node B 12,13 reference signal processing device 14,15 node information processing device 16,18,25,27 reference signal 17,19,26, 28 node information 20,29 signal synthesizer 21,30 signal separator 22,23 terminal device 24 forward transmission path 31 return transmission path 50,51 input / output port

Claims (1)

[Claims] 1. On a hierarchical network having a plurality of nodes, in which an upper node and a lower node are connected by a bidirectional signal transmission transmission line, the upper node transmits a reference signal to the bidirectional signal transmission. At least 1 using the transmission line for
In a dendritic reference signal distribution system that transmits to one lower node, reproduces the reference signal in the lower node, and then transmits it to the lower node again as a reference signal. In the route from the upper node to the lower node, when the node is the highest node, the information of its own node is added to the reference signal and transmitted, and the node is an intermediate node. Sometimes, the node information sent from the upper node is added with the information of its own node and added to the reference signal to be sent. In the route from the lower node to the upper node, the node is the lowest node. When it is a node of the node, it sends the information of its own node, and when the node is an intermediate node, it collects the node information sent from the lower node. In addition, the management information distribution and collection method is characterized in that the information of the own node is further added to the node information and transmitted.