JP2001036556A - Ring network system - Google Patents

Abstract

(57) [Summary] PROBLEM TO BE SOLVED: It is necessary to hierarchically multiplex from the 0th-order group signal of DH, and this 0th-order group signal could not be multiplexed into an STM-1 frame at a time. For this reason, there is a problem that it is necessary to pass through an LSI for hierarchical multiplexing in a plurality of stages, thereby increasing the number of circuits. SOLUTION: Multi-frame generating means for multiplexing multi-frame numbers respectively corresponding to constituent frames of a multi-frame corresponding to a terminal line at a predetermined position of a payload of a time-division multiplex frame to generate a multi-frame, A multi-frame number recognizing means for detecting a multi-frame number from a predetermined position of a payload of a time-division multiplex frame forming a frame and recognizing an arbitrary number of multi-frames is provided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a ring network system, and more particularly, to an SDH transmission line between nodes.
(Synchronous Digital Hier
archy) network, using a ring network system.

[0002]

2. Description of the Related Art In recent years, the spread of optical fibers as transmission lines has been advanced, and the bit rate on the network side has become able to cope with the increase in the bit rate on the information signal side in the network system. For this reason, it is effective to synchronize the entire network in advance and multiplex the information signal so that the bit rate on the information signal side and the bit rate on the network side are accurately adjusted. This is a synchronous multiplexing technique. Network systems using SDH have become mainstream.

In a ring network system using the above-described SDH network between a master node and a plurality of slave nodes, an STM (Syn) is used for data transmission.
(Transfer Mode) frame is used. Among the STM frames, the basic frame for data transmission in SDH is STM-1 (Sync).
Hronous Transfer Mode-lev
el 1), and 2430 bytes are converted to 155.52M
transmitted in bps.

DH (Digital Hierarch)
The process of multiplexing the zero-order group signal of y) up to the STM-1 will be described. A frame for transmitting one 8-bit line (channel) such as telephone voice at 64 kbps is called a DH 0th-order group signal.
A multiplexed signal that is multiplexed by four lines (channels) and transmitted by adding 1 bit at 1.544 Mbps is called a DH primary group signal. Multiplexing in a network system does not involve collecting a large number of zero-order group signals of the DH and multiplexing them at once, but collecting and multiplexing some of the signals and further collecting and multiplexing some of the multiplexed signals. A method of repeating this is taken. Some of them are described below.

[0005] The 8th bit of the 0th order group signal of DH is collected by 24 lines (channels), and 1 bit is added thereto, thereby obtaining the 1st order group signal of DH. 2 required for line monitoring and maintenance
The byte overhead and the extra 7 bits are
Of the 27-byte VC-1 (Vir)
A multiplexed hierarchical frame referred to as “tual Container-1) is configured. This VC-1 frame is
A multiplexed hierarchical frame called VC-3 is obtained by multiplexing eight frames and adding a 9-byte overhead.
18 bytes are added to this VC-3 frame, and 3 bytes are added.
When this is multiplexed, it becomes 2349 bytes, and when an overhead of 81 bytes is added thereto, an STM-byte of 2,430 bytes is added.
One frame.

In addition to the above, 64 kb of the 0th order group signal
30 lines (channels) of 30 ps voice lines are collected and multiplexed by 30 bytes to form a 2.048 Mbps frame, four of which are multiplexed to form a 8.448 Mbps frame, and four more frames are multiplexed. 34.368
A frame of 139.264 Mbps is constructed by multiplexing four of these frames, and a 9-byte overhead is added to the frame to form a VC-
4 (Virtual Container-4) is constructed, and an overhead is added to the multiplexed hierarchical frame to add an overhead to the STM-frame having a transmission rate of 155.52 Mbps.
One frame is composed.

In the conventional ring network system, when data is transmitted in the above STM-1 frame, the slave node is subordinately synchronized with the received STM-1 frame, and the line data connected to its own node is transmitted. After being separated / multiplexed from the data portion of the STM-1 frame, and transmitted to the next slave node or master node via the transmission path. Further, the master node receives the received S
The ring delay is corrected between the TM-1 frame and the time-division frame generated by the master node itself, and the transmission delay between the master node and the slave node or the transmission path between the slave nodes is determined. Some or all of them used SDH networks. A clock master node serving as a clock source for data transmission in the ring has been set in advance by a switch or the like.

In the ring network system using the SDH network as described above, the STM-1 used for this is used.
VC-4 POH (Pass OverH) in the frame
Since the H4 pointer in E.ad.) is a multi-frame synchronization pattern, the STM-1 frame does not correspond to an arbitrary number of multi-frames.
-T (International Telecomm)
unionUnion-Telecommun
4) are defined as one multi-frame or 24 frames as one multi-frame.

As related to the present invention, Japanese Patent Laid-Open No. 5-1
No. 45566 discloses a method in which one multi-frame is set to 20 frames. Specifically, one multi-frame is used as a multi-frame synchronization pattern in one time slot in C4 in an STM-1 frame. 2
This is for multiplexing information to be set to 0 frame.

[0010]

Since the conventional ring network system is configured as described above,
It is necessary to hierarchically multiplex from the 0th-order group signal of H, and this 0th-order group signal could not be multiplexed into an STM-1 frame at a time. For this reason, there is a problem that it is necessary to pass through an LSI for hierarchical multiplexing in a plurality of stages, thereby increasing the number of circuits.

In general, when a terminal interface corresponding to a multi-frame is used, if the frame unit of one multi-frame corresponding to each terminal interface is different, the frame unit to be recognized is changed accordingly. Is required. However, as described above, in the STM-1 frame, one multi-frame corresponds only to a unit of 4 or 24 frames, and transmission cannot be performed in a multi-frame of an arbitrary frame corresponding to each terminal interface. was there.

Further, in the conventional ring network system using the STM-1 frame, since a clock master node serving as a time reference for network synchronization is set in advance, if a failure occurs in this clock master node, There has been a problem that data transmission between other nodes cannot be performed.

Further, when the STM-1 multi-frame is realized, there is a problem that the delay of the multi-frame is corrected in each node and the delay time in the node increases.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problems, and provides an STM frame in which the unit of a multi-frame is variable and makes the node which is a clock master node variable to be suitable for a clock master. It is an object of the present invention to provide a ring network system which has a function of automatically determining a node which has failed and which minimizes a delay time in the node.

[0015]

In a ring network system according to the present invention, at least one of a plurality of nodes is connected to a terminal line corresponding to a multi-frame of an arbitrary number of frames, and a multi-node corresponding to the terminal line is connected. A multi-frame master node having multi-frame generating means for multiplexing a multi-frame number corresponding to each of the constituent frames of the frame at a predetermined position of the payload of the time-division multiplex frame to generate a multi-frame of the time-division multiplex frame; Provided in each of a plurality of nodes, when receiving a multiframe, detects a multiframe number from a predetermined position of a payload of a time division multiplex frame constituting the multiframe, and recognizes the multiframe of an arbitrary number of frames. Multi-frame number recognition means. It is.

In the ring network system according to the present invention, each of the plurality of nodes has a node priority indicating the priority of the operation clock of the node connected in the ring set in advance, and the node priority is set to the payload. A node priority multiplexing means for generating a time-division multiplex frame multiplexed at a predetermined position and transmitting the generated time-division multiplex frame to another node; and a node detected from the node priority set in advance for the own node and the payload of the received time-division multiplex frame. A node priority comparing unit that compares the priority with the node; and a node priority setting unit that sets a node priority of the own node based on a comparison result of the node priority comparing unit. At the start of the operation, the node priority set in advance for the own node is set to the predetermined position of the payload of the time-division multiplex frame. The node priority setting means, upon receiving the time-division multiplexed frame, transmits the node priority having a higher priority to the node priority multiplexing means based on the comparison result of the node priority comparing means upon receiving the time-division multiplexed frame. If the priority shows the same value continuously for a predetermined number of times, the own node is set as the clock master node.

In the ring network system according to the present invention, the node to which the highest-order node priority is set is connected to a terminal line corresponding to a multi-frame of an arbitrary number of frames, and A multi-frame number corresponding to each of the constituent frames is multiplexed at a predetermined position of the payload of the time-division multiplex frame,
A multi-frame master node comprising a multi-frame generating means for generating a multi-frame of the time-division multiplex frame, wherein each of the plurality of nodes, when receiving the multi-frame, determines a payload of a time-division multiplex frame constituting the multi-frame. A multi-frame number recognizing means for detecting a multi-frame number from a position and recognizing an arbitrary number of multi-frames is provided.

In the ring network system according to the present invention, when all nodes except the clock master node receive a multiframe of a time division multiplex frame, the node transmits the multiframe without holding one or more frames. .

The ring network system according to the present invention includes node priority management means for collectively managing node priorities.

In the ring-type network system according to the present invention, each of the plurality of nodes is set in advance with a node priority indicating the priority of the operation clock of the node connected in the ring, and the node priority is set to the payload. A node priority multiplexing means for generating a time-division multiplex frame multiplexed at a predetermined position and transmitting the generated time-division multiplex frame to another node; and a node detected from the node priority set in advance for the own node and the payload of the received time-division multiplex frame. A node priority comparing unit for comparing the priority with the node; and a node priority setting unit for setting a node priority of the own node based on a comparison result of the node priority comparing unit. When a failure occurs in the clock master node, the node separates the clock master node and disconnects the clock master node. To form a network by sending passage,
A failure detection signal is transmitted to other nodes connected to the network, and each node connected to the network generates a time-division multiplexed frame in which a node priority set in advance for the own node is multiplexed at a predetermined position of the payload. When the time-division multiplexed frame is received by transmitting the time-division multiplexed frame to another node and receiving the time-division multiplexed frame, the node priority is set by the node priority order comparing means and the node priority detected from the payload of the time-division multiplexed frame The priority is compared with the order, and the node priority setting unit causes the node priority order multiplexing unit to transmit the node priority having the higher priority in the comparison result of the node priority order comparing unit. , Its own node as a new clock master node.

In the ring network system according to the present invention, the clock master node includes an external clock input means for inputting an external operation clock, and an operation clock for selectively setting an external operation clock and an operation clock of the own node. Selection setting means and node priority control means for setting the node priority of the own node to the highest priority when the operation clock from the outside is normal, and for lowering the priority of the node priority when there is an abnormality. It is further characterized by being provided.

[0022]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below. Embodiment 1 FIG. FIG. 1 is a block diagram showing a configuration of a ring network system according to Embodiment 1 of the present invention. In the figure, reference numeral 1 denotes a network transmission line connecting the master node 2 and the slave nodes 3 and 4, and uses a frame conforming to the SDH division multiplexing method. Reference numeral 2 denotes a master node, which in the first embodiment is a clock master node (set by a switch or the like) for determining a network synchronization clock serving as a time reference for data transmission in the ring, and is also a multi-frame master node described later. . Reference numeral 3 denotes a slave node having no terminal line interface 5, and 4 denotes a slave node having the terminal line interface 5.
These slave nodes 3 and 4 operate according to the operation clock of master node 2. Reference numeral 5 denotes a terminal line interface. In the illustrated example, the terminal line is connected to ITU-TG. 70
The data line specified in 3. 6 is a line transmission line connected to the terminal line interface 5 and 7 is a TDM (Tim
An eDivision Multiplex (eDivision Multiplex) device, which speeds up and multiplexes a plurality of digital signals (bytes) in a fixed time (frame). 8 is the master node 2
Is a multi-frame generation unit that generates multi-frame numbers corresponding to the constituent frames of the multi-frame at its own timing, and constitutes a multi-frame generation unit. A node having the multi-frame generation unit 8 and generating a multi-frame number in this manner is referred to as a multi-frame master node. Reference numeral 9 denotes a multi-frame transmission / reception unit that performs multi-frame transmission / reception processing of each node, and a part of the multi-frame transmission / reception unit 9 constitutes a multi-frame number recognition unit.

FIG. 2 is a configuration diagram of an STM-1 frame used in the ring network system of the present invention.
As described above, the STM-
One frame has a size of 2430 bytes = 270 bytes × 9 rows. This configuration is composed of an SOH (Section OverHead), which is a 9-byte × 9-row portion on the left side,
It consists of a payload of 261 bytes × 9 rows.
The SOH is a section for inputting a signal for managing and maintaining the state of a transmission section (section) or a multiplex section, and is composed of A1 and A2 indicating a frame pattern, C1 which is an STM identifier, and the like. The payload is an area for storing data, and all multiplexed existing DH signals are stored here. In FIG. 2, the first 9 bytes of the payload include a multi-frame number section in which a multi-frame number described later is multiplexed and a node priority number section in which the node priority described in the second embodiment is multiplexed.

FIG. 3 is a block diagram showing a configuration in a node of the ring network system according to the first embodiment of the present invention. In the figure, 10 is the received STM-1
STM-1 frame synchronization detecting section for detecting frame synchronization of a frame (reception of an operation clock); 11, an STM-1 termination section for analyzing SOH of the STM-1 frame; and 12, a multi-frame number from the received STM-1 frame. Is extracted. These ST
M-1 frame synchronization detection unit 10, STM-1 termination unit 11
The multi-frame synchronization detecting section 12 constitutes a multi-frame transmitting / receiving section 9 as multi-frame number recognizing means. Reference numeral 13 denotes a delay correction frame / multiframe pulse generation unit which performs reception processing in accordance with the multiframe number extracted by the multiframe synchronization detection unit 12 together with the demultiplexing memory unit 14, and 15 generates a multiframe synchronization pattern and transmits the multiframe synchronization pattern. This is a multi-frame synchronization pattern insertion unit that outputs to a multi-frame synchronization pattern.

Reference numeral 16 denotes an SOH adding unit, and 17 denotes an STM-1 frame synchronization pattern adding unit. The STM-1 frame synchronization pattern adding unit 17 transmits the STM-1
The frame information of the multiplexed signal to be transmitted to the SOH of the TM-1 frame is added. In the master node 2, the multi-frame generating unit 8 is configured by a multi-frame generating unit, a multi-frame number recognizing unit, and the like including the above components. 5a and 5b are terminal line interfaces on the receiving side and the transmitting side which constitute the terminal line interface 5;
The case of the slave node 3 is omitted.

Next, the operation will be described. As shown in FIG. 1, the multiplexed signal transmitted from the TDM 7 passes through the line transmission line 6 and is terminated at the terminal line interface 5. Here, in the illustrated example, the terminal line is ITU-TG. Since the data is 1.544 Mbps data corresponding to 703, it is defined that 24 or 12 frames constitute one multi-frame at the first bit (frame synchronization bit: F bit). 1 multiframe is 12
If the frame is a frame (24 frames), the LSB (Least Significa) of the sixth frame, the twelfth frame, and the (eighteenth frame, the twenty-fourth frame) from the top of the frame.
nt Bit) is a signal bit. Thus, in order to recognize the signal bits, the multi-frame may have a six-frame configuration.

The master node 2 that has obtained digital data from the terminal line interface 5 has a terminal line of ITU-T.
G. FIG. Since the data corresponds to data 703, the multi-frame generation unit 8 generates multi-frame numbers 0 to 5 for six frames at its own timing. The multi-frame numbers (0 to 5) are stored in the leading 9 bytes of the payload shown in FIG. 2 and transmitted every six frames so as to match the signal bits for every six frames on the terminal line side. The slave nodes 3 and 4 synchronize subordinately to the received STM-1 frame (the master node 2 is set as the clock master node in the first embodiment), and the multiframe number is used as the multiframe number of the own node. The signal bits on the terminal line side can be recognized from the frame number.

The above operation will be specifically described with reference to FIG. When each node receives the multi-frame composed of the STM-1 frame, the frame is synchronized by the STM-1 frame synchronization detecting unit 10, and the STM-1 termination unit 11 analyzes the SOH of the STM-1 frame. Then, the relative position in the frame is identified, and information indicating the head position of the multiplexed signal, that is, the head position of the payload is extracted. Based on the information indicating the head position of the payload, the multi-frame synchronization detection unit 12 extracts the multi-frame number multiplexed on the multi-frame number part of the first nine bytes of the payload.

The STM-1 received by the delay correction frame pulse / multiframe pulse generation unit 13 and the demultiplexing memory unit 14 according to the multi-frame number of the received STM-1 frame (corresponding to the signal bits for every six frames).
The reception processing of the multiplexed signal of the frame is performed. At this time, a delay occurs between the multi-frame number of the receiving-side STM-1 frame and the multi-frame number of the transmitting-side STM-1 frame for a certain period due to the relay of the data of each node. Generates a multi-frame pulse corresponding to the transmitting side. The demultiplexing memory unit 14 receives the STM-1
According to the multi-frame number of the frame, the received ST
A predetermined signal sequence is separated from the multiplexed signal of the M-1 frame, and conversely, time-division multiplexing of the signal sequence is performed in synchronization with the delay-corrected multi-frame pulse.
The delay correction between the data of one frame and the data of the STM-1 frame on the transmission side is performed. Further, the slave node 4 transmits and receives data to and from the terminal line interfaces 5a and 5b according to the extracted multi-frame number.

The process of transmitting multiplexed data to the next node will be described. In the slave nodes 3 and 4,
The multi-frame synchronization pattern insertion unit 15 and the delay correction frame pulse / multi-frame pulse generation unit 13 generate transmission timing. More specifically, the demultiplexing memory unit 14 performs multiplex insertion of data from the received multi-frame pulse to generate a transmission multi-frame pulse and outputs it to the multi-frame synchronization pattern insertion unit 15. The multi-frame synchronization pattern insertion unit 15 that has received the transmission multi-frame pulse inserts a multi-frame number into a portion corresponding to the first 9 bytes of the payload of the STM-1 of the transmission data based on the transmission multi-frame pulse. A pattern is generated.

In the master node 2, the delay correction frame pulse / multiframe pulse generator 13 that has received the received multiframe pulse generates a delay between the received STM-1 frame and the transmission STM-1 frame generated by the master node 2 itself. After the correction, the transmission multi-frame pulse and the like after the delay correction are output to the demultiplexing memory unit 14. The demultiplexing memory unit 14 multiplexes data into the transmission multi-frame pulse and outputs the transmission multi-frame pulse to the multi-frame synchronization pattern insertion unit 15. Upon receiving the transmission multi-frame pulse, the multi-frame synchronization pattern insertion unit 15 inserts a multi-frame number into a portion corresponding to the first 9 bytes of the payload of the STM-1 of the transmission data based on the transmission multi-frame pulse, and transmits the transmission multi-frame synchronization. A pattern is generated.

The SOH adding section 16 adds SOHs other than A1, A2 and C1 shown in FIG. 2 to the transmission multi-frame synchronization pattern obtained by multiplexing a predetermined signal in the demultiplexing memory section 14, and adds the STM-1 frame synchronization pattern. Part 17
The SOH of A1, A2 and C1 in FIG.
A multi-frame of the TM-1 frame is formed and transmitted to the next node.

As described above, the multi-frame number is generated at the own node timing of the master node 2, and the STM-1
The data is stored and transmitted in the first 9 bytes of the payload shown in FIG. 2 every six frames so as to match the signal bits on the terminal line side of the frame. On the other hand, since the slave nodes 3 and 4 generate the multi-frame synchronization pattern of the transmission STM-1 frame in accordance with the multi-frame number of the received STM-1 frame, all the nodes use the same synchronization pattern to generate the multi-frame synchronization pattern. Can be synchronized.

In the above-described embodiment, the number of multiframes is six. However, the number of multiframes is not limited to six. The number of multiframes may be any number of frames corresponding to a terminal line connected to a node. Can be.

In the above-described embodiment, since synchronization is performed using the multiframe number stored in the payload of the STM-1 frame, data is stored in the payload of the STM-1 frame in a hierarchical structure composed of VCs defined by POH. Even a configuration without multiplexing can be supported.

As described above, according to the first embodiment, a terminal line corresponding to a multi-frame having an arbitrary number of frames and a multi-frame number corresponding to each of the constituent frames of the multi-frame corresponding to the terminal line Is a time division multiplex frame used for data transmission in the ring, S
Multiplexed at a predetermined position of the payload of the TM-1 frame,
A master node 2 which is a multi-frame master node including a multi-frame generation unit 8 as multi-frame generation means for generating a multi-frame of an STM-1 frame
Provided in each of the plurality of nodes, upon receiving a multi-frame, detecting a multi-frame number from a predetermined position of the payload of the STM-1 frame constituting the multi-frame, and recognizing the multi-frame of an arbitrary number of frames. And a multi-frame transmitting / receiving unit 9 as multi-frame number recognizing means, which is used in the existing terminal device even in a configuration in which a 64 kbps signal, such as a 0th order group signal of DH, is directly multiplexed into the payload of the STM-1 frame. It becomes possible to cope with the multi-frame of various frame units which has been used. More specifically, since the multi-frame number multiplexed on the payload of the STM-1 frame is used for synchronizing the multi-frames, it is not necessary to configure a hierarchical structure using VCs having a POH. This makes it possible to easily connect to an existing terminal device without requiring a conversion device for converting the number of frames of a multi-frame. Further, there is no need to go through an LSI for hierarchical multiplexing in a plurality of stages, and there is no increase in circuit. Furthermore, if the multi-frame master node is determined according to the connected terminal line, it is possible to provide a ring-type network system that can handle an arbitrary number of frames.

Embodiment 2 In the first embodiment, the master node 2 which is a multi-frame master node is preset so as to be a clock master node which is a clock source in the ring. In the second embodiment, the master node 2 is connected in the ring. Node priorities indicating the priorities of the operation clocks between the nodes are set in each node, and these are multiplexed in a ring to determine an optimal node as a clock master node.

FIG. 4 is a block diagram showing a configuration of a ring network system according to Embodiment 2 of the present invention. In the figure, reference numeral 2 'denotes a clock master node for operating other connected nodes in the ring by the operation clock of the own node, 3' a slave node having no terminal line interface 5, and 4 'having a terminal line interface 5. Slave node. Reference numeral 18 transmits the node priority set in the own node, compares the received node priority with that of the own node, sets the higher priority as the node priority of the own node, and sets this node priority. This is a node priority transmission / reception unit that transmits the order to other nodes. Node priority multiplexing means, node priority comparing means, and the like constitute this node priority transmission / reception section. In addition,
The same components as those in FIG. 1 are denoted by the same reference numerals, and redundant description will be omitted.

FIG. 5 is a block diagram showing a configuration of each node of the ring network system according to the second embodiment of the present invention. In the figure, 10 'is the received STM-
Detects frame synchronization of one frame (operation clock received)
STM-1 frame synchronization detecting unit 11 'is an STM-
STM-1 terminal for analyzing SOH of one frame, 1
Reference numeral 4 'denotes a demultiplexing memory unit for multiplexing data into a payload of an STM-1 frame. 16 'is an SOH adding unit, and 17' is an STM-1 frame synchronization pattern adding unit. The SOH adding unit 16 'and the STM-1 frame synchronization pattern adding unit 17' add the SOH to the payload in which the node priority comparing unit 22 multiplexes the node priority in the node priority number shown in FIG. One frame is assumed. The SOH adding section 16 'and the STM-1 frame synchronization pattern adding section 17' constitute a node priority transmission / reception section 18 as a node priority multiplexing means. 5
Reference numerals a 'and 5b' denote terminal line interfaces on the receiving side and the transmitting side which constitute the terminal line interface 5, and are omitted in the case of the slave node 3 '.

Reference numeral 20 denotes a node priority order extraction unit for extracting a node priority order from the node priority order number part of the payload of the received STM-1 frame, and 21 denotes a node priority order setting means for setting the node priority order. The setting unit 22 is a node priority comparing unit corresponding to a node priority comparing unit that compares a node priority of the received STM-1 frame with a node priority set in advance for the own node. A clock selection unit 23 causes the clock generation unit 24 to generate an operation clock based on the comparison result of the node priority comparison unit 22.

Next, the operation of determining the clock master node of the ring network system according to the second embodiment will be described. Each node is preset with a node priority of 0 to 255 indicating the priority of the operation clock between the nodes. Also, when power is turned on, that is, in the second embodiment,
When the ring network system is started up, all the nodes connected in the ring are set to be clock master nodes that operate on the operation clock of the own node. At this time, in each of the nodes connected in the ring, the node priority comparison unit 22 compares the node priority set in advance to the predetermined position of the payload (in the example of FIG. 2, the node priority of the first 9 bytes of the payload). The SOH adding section 16 'and the STM-1 frame synchronization pattern adding section 17' add an SOH to the payload to generate an STM-1 frame which is a time division multiplexed frame. The clock master node 2 'sends this STM-1 frame to the next node at the timing of its own node.

In the next node receiving the STM-1 frame, the STM-1 frame synchronization detecting unit 10 'obtains frame synchronization (operation clock reception) by using the STM-1 frame synchronization detection unit 10'.
The S-1 of the STM-1 frame is
By analyzing the OH, the relative position in the frame is identified, and information indicating the head position of the multiplexed signal, that is, the head position of the payload is extracted. Based on the information indicating the head position of the payload, the node priority extracting unit 20 extracts the node priority multiplexed in the node priority number part of the first nine bytes of the payload. The node priority extracted from the STM-1 frame is determined by the node priority comparison unit 22.
And compares the priority of the node with a node priority preset for the own node.

In the comparison of the node priorities by the node priority comparing section 22, if the node priorities detected from the STM-1 frame are lower than the preset node priorities, the predetermined node priorities are compared. The order is multiplexed with the node priority number part of the payload of the STM-1 frame and transmitted to the next next node.
If the node priority detected from one frame is equal to or higher than the preset node priority, the node priority detected from the STM-1 frame is changed to the node priority number part of the payload of the STM-1 frame. And transmit it to the next node. By doing so, the priority of the node priorities multiplexed in the ring increases. If the node priority detected from the STM-1 frame and the preset node priority indicate a value equal to a predetermined number of times, the node is determined to have the highest preset node priority, and Is determined as the clock master node, and the node priority comparison unit 22 controls the clock selection unit 23 to cause the clock generation unit 24 to generate an operation clock. Other nodes connected in the ring are STMs transmitted from this node.
-1 frame to STM-1 frame synchronization detector 10 '
Becomes a clock slave node operated by the detected reception clock.

The predetermined number of times is calculated by calculating a delay in a memory in a node and a delay in a transmission line as a relay delay of data in the ring, and calculates a time for data to reach all nodes connected in the ring. It is determined by calculation. This number varies depending on the configuration of the system (how many nodes are connected in the ring). In the above embodiment, the maximum number is 128.

As described above, according to the second embodiment, each of the plurality of nodes is set in advance with the node priority indicating the priority of the operation clock of the node connected in the ring. An STM-1 frame in which the order is multiplexed at a predetermined position of the payload is generated, and the ST
SOH adding section 1 for sending M-1 frame to another node
6 'and STM-1 frame synchronization pattern adding unit 17'
A node priority comparing unit 22 that is a node priority comparing unit that compares a node priority set in advance for the own node with a node priority detected from the payload of the STM-1 frame. A node priority setting unit 2 that sets the node priority of the own node based on the comparison result of the node priority comparison unit 22
1, the node priority multiplexing means multiplexes the node priority set in the own node at the start of the operation at a predetermined position of the payload of the STM-1 frame, and transmits the multiplexed signal with the operation clock of the own node. The unit 21 causes the node priority multiplexing unit to transmit the node priority having the higher priority as a result of the comparison by the node priority comparison unit 22, and when the priority shows the same value for a predetermined number of consecutive times, places the own node in the ring. Since the other connected node is the clock master node that operates with its own operation clock, if the node priority is set according to the degree of the most suitable clock source among the nodes connected in the ring In the case where the clock master node 2 ′ fails to function due to a power failure or the like, the optimum node is determined and determined as the clock master node. Communication between nodes can be secured.

Embodiment 3 The third embodiment has a function in the ring network system according to the first and second embodiments.

FIG. 6 is a block diagram showing a configuration of a ring network system according to Embodiment 3 of the present invention. In the figure, 2 ″ is a master node having both functions of the multi-frame master node according to the first embodiment and the clock master node according to the second embodiment,
3 ″ is a slave node having no terminal line interface 5, and 4 ″ is a slave node having a terminal line interface 5. Reference numeral 8 'denotes a multi-frame generating unit which generates a multi-frame number corresponding to each of the multi-frame constituent frames at its own timing of the master node 2'', and constitutes a multi-frame generating means. 28
5 shows the functions of the multi-frame synchronization detection unit 10, the delay correction frame pulse / multi-frame pulse generation unit 13 and the multi-frame synchronization pattern insertion unit 15 in FIG.
Is a control information receiving unit having the functions of the node priority order extraction unit 20, the node priority order setting unit 21, and the node priority order comparison unit 22. The other components are the same as those in FIG. 1, and are denoted by the same reference numerals, and redundant description will be omitted.

Next, the operation will be described. Here, the determination operation of the master node 2 ″ having the functions of the clock master node and the multi-frame master node will be described. First, a clock master node is determined in the same manner as in the second embodiment. At this time, the node priority is set according to the degree of being most suitable as a clock source for each node connected in the ring, and the node most suitable as this clock source also functions as a multi-frame master node. The multi-frame generation unit 8 'is installed in a node having a higher priority. By doing so, the multi-frame master node is determined at the same time as the clock master node. Also,
The clock master / multiframe master node determined as described above includes a multiframe number portion and a node priority number portion at a predetermined position (the first 9 bytes) of the payload of the STM-1 frame shown in the example of FIG. The control information is multiplexed with the multiframe number and the node priority and transmitted to each node.

As described above, according to the third embodiment, the clock master node determined in the same manner as in the second embodiment also functions as a multi-frame master node. The function of the multi-frame master node can be automatically determined at the same time, and there is no need to be conscious of the setting of the multi-frame master node, so that the effect of saving labor in management can be obtained.

Embodiment 4 In the fourth embodiment, an STM received at a node other than the clock master node
This control is performed so that the phase difference between the -1 frame and the STM-1 frame to be transmitted is minimized.

FIG. 7 is a block diagram showing a configuration of a ring network portion of a ring network system according to Embodiment 4 of the present invention. In the figure,
Reference numeral 2a denotes a master node, which is a clock master node for determining a clock serving as a time reference for data transmission in the ring, and is also a multi-frame master node. Reference numeral 3a denotes a slave node that operates according to the operation clock of the master node 2a, which is a clock master node. Reference numeral 8a denotes a multi-frame generation unit that generates a multi-frame number corresponding to each of the multi-frame constituent frames at the own node's own timing, and 9a denotes a multi-frame transmission / reception unit that performs multi-frame transmission / reception processing of each node. Yes, and constitutes a multi-frame number recognition means.
Note that the same components as those in FIG. 1 are denoted by the same reference numerals, and redundant description is omitted. A delay buffer (not shown) is provided in the multi-frame transmission / reception section 9a, and STM-1 for receiving
Control is performed to minimize the phase difference between the frame and the STM-1 frame to be transmitted.

Next, the operation will be described. FIGS. 8 and 9 are explanatory diagrams showing the STM-1 and the frame / bus phase of the data bus in the slave node 3a and the master node 2a of the ring network system according to the fourth embodiment of the present invention, respectively. As shown in FIG. 8, the slave node 3a controls a delay buffer (not shown) in the multi-frame transmission / reception unit 9a so that the multi-frame number on the received STM-1 frame and the data to be multiplexed on the transmitted STM-1 frame. And the same multi-frame number of the data bus. As a result, the slave node 3a ensures that the number of frames accumulated before transmitting the multiframe is within one frame.

The master node 2a serves as a reference for the STM-1 frame phase and a reference for the multi-frame phase in addition to the reference for the operation clock in the ring. Thus, in order to adjust the multi-frame phase in the master node 2a, the relay memory from the data bus to the STM-1 frame has a capacity capable of storing the number of frames for one multi-frame. Therefore, at the worst, a delay of one multi-frame occurs when relaying the STM-1 frame. FIG. 9 shows an example in which one multi-frame is made up of six frames. In this case, the master node 2a stores the data within 1 to 6 frames, transmits it to the next node with the operation clock of its own node, and sends it to the ring network system. The fact that the data delay varies depending on the number of connected nodes is absorbed by the master node 2a.

In the above embodiment, the case where the multi-frame master node is the clock master node has been described. However, when the multi-frame master node is not the clock master node, the multi-frame master node also functions as the clock slave node. So that the number of frames stored before transmitting a multi-frame is within one frame.

As described above, according to the fourth embodiment, when all nodes except the clock master node 2a receive the multi-frame of the STM-1 frame, the transmission of the multi-frame does not hold one or more frames. Is performed, the delay time of the node relay time can be minimized. As a result, the transfer delay time in the node can be reduced.

Embodiment 5 In the second embodiment, the node priorities are set in advance for each node. However, in the fifth embodiment, a node priority management means for collectively managing the node priorities of the nodes is provided.

FIG. 10 is a block diagram showing a configuration of a ring network system according to a fifth embodiment of the present invention. FIG. 11 is connected to a management device 40 of the ring network system according to the fifth embodiment of the present invention. FIG. 3 is a block diagram illustrating a configuration of a node that is present. In the figure, 2
b is a clock master node that determines a clock that is a time reference for data transmission in the ring, 3b and 4b are slave nodes that operate according to the operation clock of the master node 2b, and 3b is a slave that does not have the terminal line interface 5. The nodes 4b are slave nodes having the terminal line interface 5. Reference numeral 38 denotes a node priority reception comparison unit which extracts and compares the node priority from the node priority number area of the payload of the received STM-1 frame. 40 is a management device, 41 is a register unit set to have the same function as the node priority order setting unit 21 shown in FIG. 5, 42 is a CPU unit 43 and a register unit 41
And 43, a CPU device that communicates and controls the set values of the management device 40 to all nodes.
These constitute a node priority management means for managing the node priorities of the nodes connected in the ring. 10 includes an STM-1 frame synchronization detecting section 10 ', an STM-1 terminating section 11', a node priority extracting section 20, a node priority comparing section 22, and a register section 41. You. 1 and 5 are the same components, and duplicate description will be omitted.

Next, the operation will be described. Management device 40
When the node priority order is set in, the setting information is input to the CPU device 43. The CPU device 43 is a CPU
The signal is sent to the register section 41 through the bus 42 and the register section 4
The node priority set in the management device 40 input to 1 is sent to the node priority comparison unit 22, and the clock master node is determined as in the second embodiment.

The setting in the management device 40 is performed by the CPU.
By using the communication between the CPU devices by the device 43, the register units 4 of all the nodes connected in the ring can be used.
1 can be changed. Accordingly, the clock master node can be changed by collectively setting the node priorities of all the nodes connected in the ring in the management device 40.

Note that, unlike the case of the second embodiment,
Since the node priority is not set by switch, a reset operation by turning on the power supply is not required. Therefore, the node priority setting operation of the above embodiment can be performed during the operation of the system.

As described above, according to the fifth embodiment, the node priority order is collectively managed, and the node priority order management means including the management device 40, the register unit 41, the CPU bus 42, and the CPU device 43 is provided. Therefore, the node priority can be set at one place, and the clock master node can be changed from one place by changing the setting. As a result, maintenance of the system can be facilitated.

Embodiment 6 FIG. In the sixth embodiment, when the clock master node determined in the second embodiment fails to function due to a failure, a new clock master node is set using the clock master node determination function described in the second embodiment. It is something that can be done.

FIG. 12 is a block diagram showing a configuration of a ring network system according to Embodiment 6 of the present invention. In the figure, reference numeral 1a denotes a network transmission line connecting the master node 2A and the slave nodes 3A and 3B.
b is a transmission line for backup of the transmission line 1a, SD
A frame conforming to the H division multiplex system is used. 2A is a clock master node that determines a network synchronization clock that serves as a time reference for data transmission in the ring. 3A, 3B
Is a slave node that operates according to the operation clock of the master node 2A, the slave node 3A is located next to the clock master node 2A, and the slave node 3B is a slave node connected to the other. The X symbol attached to clock master node 2A indicates that node 2A
Indicates that it has stopped functioning due to a failure.

Next, the operation will be described. When the clock master node 2A stops functioning due to a power failure or the like, the slave nodes 3A and 3A, which are the next nodes after the clock master node 2A, detect the failure and disconnect the clock master node 2A to use the backup transmission line 1b. Form a network with dual transmission paths. The subsequent clock master node determination operation will be described in detail with reference to FIG.

FIG. 13 is an explanatory diagram for explaining a clock master node determining operation of the ring network system according to the sixth embodiment. In the figure, N1 to N4 are nodes connected in the ring, and the S and M symbols attached to these nodes indicate a clock slave node and a clock master node, respectively.

The state shown in FIG. 13A is a configuration when the ring network system is normal.
At this time, the clock master node N4 has the highest node priority, and the other nodes N1 to N3 operate according to the operation clock of the clock master node N4. Further, similarly to the second embodiment, each node N1
Node priorities corresponding to the nodes are set in advance in .about.N4.

The state in FIG. 13 (b) shows a case where a failure has occurred in the clock master node N4, and the x symbol attached to the node N4 indicates that the function suspension has been stopped due to the failure. When the occurrence of this failure is detected by the nodes N1 and N3 next to the clock master node N4, the state transits to the clock master node. Triggered by this failure detection, the nodes N1 and N3 transmit failure occurrence information to other nodes.

Thereafter, as shown in FIG. 13 (c), the failed node N4 is disconnected, and a new network is formed by a double transmission line composed of nodes N1 to N3.
The nodes N1 and N3 transmit the failure occurrence information to the network (continue for a fixed time (72 ms: an example)).

Thereafter, the nodes N1 and N3 multiplex the lowest node priority on the network. More specifically, the node priority setting unit 21 sets the lowest node priority, generates an STM-1 frame multiplexed at a predetermined position of the payload, and transfers the STM-1 frame on the network. Send to

In the state shown in FIG. 13D, the node N2 transmits the failure occurrence information from the nodes N1 and N3 to the STM-
When it is detected by the 1 terminating unit 11 ', it becomes a clock master node that operates with its own operation clock, and relays the fault occurrence information on the network (for a fixed time (72
ms: continued during one example). Thereafter, the node N2 also sets the lowest node priority in the node priority setting unit 21 and multiplexes this in a predetermined position of the payload.
Generate a frame and transmit this STM-1 frame over the network.

All the nodes N1 to N3 connected to the newly formed network by the above operation become the clock master nodes, and the priority of the multiplexed nodes in the network becomes the lowest and the power is turned on. It becomes the same state as.

The subsequent clock master node discriminating operation is the same as that described in the second embodiment, and a description thereof will be omitted.

FIG. 13E shows that the node N1 is determined as the node most suitable for the clock master node in this network as described above, and the other nodes N2 and N3 are multiplexed on the network with their own node priority. The calculated node priority is compared with that of the own node until it becomes lower, and the node becomes the clock slave node.

The above-mentioned clock master node determination operation is not limited to the configuration of the sixth embodiment, but can be applied to all embodiments if the transmission path is duplicated.

As described above, according to the sixth embodiment, when a failure occurs in the clock master node, the next node of the clock master node disconnects the clock master node and disconnects the network by the dual transmission path. And transmits a failure detection signal to other nodes connected to the network, and each node connected to the network multiplexes a node priority set in advance in its own node at a predetermined position of the payload by time division. When a multiplex frame is generated, the time division multiplex frame is transmitted to another node with the operation clock of the own node, and the time division multiplex frame is received,
The node priority comparing means compares the node priority preset for the own node with the node priority detected from the payload of the time division multiplex frame, and the node priority setting means gives priority to the comparison result of the node priority comparing means. If the higher priority node priority is transmitted to the node priority multiplexing means, and if the priority shows the same value continuously for a predetermined number of times, the own node is set as a new clock master node, so that the clock master node does not function due to a failure. In this case, communication between nodes other than the clock master node can be secured, and the clock master node can be automatically switched.

Embodiment 7 In the above embodiment, the operation is performed by the operation clock generated by the nodes constituting the ring, and the priority of the operation clock is determined by the node priority. In the seventh embodiment, the operation clock is supplied from outside the node. Is controlled on the basis of the external clock input means for supplying the operation clock and the supplied operation clock.

FIG. 14 is a block diagram showing a configuration of a ring network system according to Embodiment 7 of the present invention. In the figure, 2B is a clock master node for operating other connected nodes in the ring with the operation clock of its own node, 3B is a slave node having no terminal line interface 5, and 4B is a slave node having a terminal line interface 5. is there. 18a transmits the node priority set to the own node, compares the received node priority with that of the own node, sets the higher priority as the node priority of the own node, and sets this node priority. This is a node priority transmission / reception unit that transmits the order to other nodes. The node priority order multiplexing means and the node priority order comparing means constitute the node priority order number transmitting / receiving section.
Reference numeral 50 denotes a clock synchronizer connected to the clock master node 2B, and supplies an operation clock to the clock master node 2B. An external clock interface 51 relays the operation clock supplied from the clock synchronizer 50 into the node 2B. These clock synchronizers 5
0 and the external clock interface 51 constitute external clock input means. Note that the same components as those in FIG. 4 are denoted by the same reference numerals, and redundant description will be omitted.

FIG. 15 is a block diagram showing a configuration in each node of the ring network system according to the seventh embodiment. In the figure, reference numeral 21A denotes a node priority setting unit for setting a node priority, which constitutes an operation clock selection unit, a node priority setting unit, and a node priority control unit. Reference numeral 22 denotes a node priority comparison unit serving as a node priority comparison unit that compares a node priority of the received STM-1 frame with a node priority set in advance for the own node. Reference numeral 23A denotes a clock selection unit which causes the clock generation unit 24 to generate an operation clock based on the comparison result of the node priority comparison unit 22, and constitutes an operation clock selection unit. Note that the same components as those in FIG. 5 are denoted by the same reference numerals, and redundant description will be omitted.

Next, the operation will be described. When the power is turned on to the system and the operation is started, each node temporarily becomes a clock master node that operates with its own operation clock as in the above embodiment. Thereafter, the operation of determining the optimum node as the clock master node and setting this node as the clock master node is the same as that of the second embodiment, and therefore the description is omitted. Here, it is assumed that the clock synchronizer 50 is connected to the clock master node 2B determined as described above (connected to a node with a higher node priority). This clock synchronizer 50 outputs a clock signal corresponding to the operation clock to clock master node 2B. The clock signal from the clock synchronizer 50 is input to the external clock interface 51 in the clock master node 2B. If the clock signal is transmitted normally, the external clock interface 51
This clock signal is output to the node priority setting unit 21A and the clock selection unit 23A, and is output to the node priority setting unit 2A.
1A receives the clock signal and receives the clock signal.
The node priority of the operation clock by 0 is set to the highest order, and the clock selection unit 23 causes the clock generation unit 24 to generate the operation clock by the clock synchronizer 50.
Thus, clock master node 2B operates with the operation clock from clock synchronizer 50. further,
In the other nodes connected in the ring, the STM-1 frame synchronization detecting unit 10 'detects an operation clock by the clock synchronizer 50 from the STM-1 frame transmitted from the node 2B, and operates based on the operation clock. Clock slave node. In this way, all nodes including the clock master node 2B operate with the operation clock by the clock synchronizer 50.

On the other hand, if any failure occurs in the clock synchronizer 50, the clock signal to the external clock interface 51 is cut off, and the clock signals to the node priority setting section 21A and the clock selection section 23 are also cut off.
At this time, the node priority setting unit 21A sets the node priority of the operation clock by the clock synchronizer 50 to the low order, and the clock master node 2B sets the node priority of the operation clock by the clock synchronizer 50 in the STM-1 frame. By multiplexing and transmitting to another node, the operation shifts to the clock master node determination operation again. At this time, if another clock synchronizer is connected to another node, the operation starts immediately with the operation clock of this clock synchronizer as described above. Therefore, the node becomes a new clock master node.

As described above, in the seventh embodiment, the clock master node includes the clock synchronizer 50 and the external clock interface 51, which are external clock input means for inputting an external operation clock, and the external operation clock. When the operation clock from the outside is normal, the clock selection unit 23A and the node priority comparison unit 22, which are operation clock selection setting means for selecting and setting the operation clock of the own node, change the node priority of the own node. Since the node priority setting unit 21A is provided as a node priority control unit that lowers the priority of the node priority when there is an abnormality, the node priority setting unit 21A is provided. The clock master node can be selected by detecting the state of the clock signal. High and reliable network tonicity can be provided. In other words, for example, the second embodiment
In this case, the clock master node is determined by the node priority of the node determined in advance by switch setting or the like. In the case of this embodiment, if the clock synchronizer is connected to a plurality of nodes, one of them is Even if a failure occurs, the operation clock can be supplied from another clock synchronizer, so that scalability can be provided to the system. In addition to the switch setting of the node priority in the second embodiment, a failure of the clock synchronizer is determined, Determining node priorities can provide higher reliability.

[0082]

As described above, according to the present invention, at least one of a plurality of nodes is connected to a terminal line corresponding to a multi-frame of an arbitrary number of frames, and the configuration of the multi-frame corresponding to the terminal line is established. A multi-frame master node including multi-frame generating means for multiplexing a multi-frame number corresponding to each frame at a predetermined position of the payload of the time-division multiplex frame to generate a multi-frame of the time-division multiplex frame; A multi-frame number provided in each of the nodes, which receives a multi-frame, detects a multi-frame number from a predetermined position of a payload of a time-division multiplex frame constituting the multi-frame, and recognizes a multi-frame of an arbitrary number of frames. And the recognition means, the DH 0th-order group signal 6
Even a configuration in which a 4 kbps signal or the like is directly multiplexed into the payload of an STM-1 frame can support multi-frames of various frame units used in existing terminal devices. More specifically, since the multi-frame number multiplexed on the payload of the STM-1 frame is used for synchronizing the multi-frames, it is not necessary to configure a hierarchical structure using VCs having a POH. As a result, there is an effect that the terminal device can be easily connected to the existing terminal device without requiring a conversion device for converting the number of frames of the multi-frame. In addition, there is an effect that it is not necessary to go through an LSI for hierarchical multiplexing in a plurality of stages and the number of circuits does not increase. Furthermore, if the multi-frame master node is determined according to the connected terminal line, there is an effect that a ring network system that can support an arbitrary number of multi-frames can be provided.

According to the present invention, each of the plurality of nodes is set in advance with a node priority indicating the priority of the operation clock of the node connected in the ring, and the node priority is set at a predetermined position of the payload. A node priority multiplexing means for generating a multiplexed time division multiplex frame and transmitting the generated time division multiplex frame to another node; and a node priority set in advance for the own node and a node priority detected from the payload of the received time division multiplex frame. A node priority comparing means for comparing, and a node priority setting means for setting a node priority of the own node based on a result of the comparison by the node priority comparing means. Node priority set in advance for the node,
The node priority setting means receives the time-division multiplexed frame and multiplexes it at a predetermined position of the payload of the time-division multiplexed frame and transmits the multiplexed frame at the operation clock of the own node. The priority is transmitted to the node priority multiplexing means, and if the priority shows the same value for a predetermined number of consecutive times, the own node is set as the clock master node, so that it is most suitable as the clock source among the nodes connected in the ring. If the node priority is set according to the degree of communication, the optimal node can be determined and determined as the clock master node when the clock master node fails due to a power failure or the like. There is an effect that can be secured.

According to the present invention, the node to which the highest-order node priority is set is connected to a terminal line corresponding to a multi-frame of an arbitrary number of frames, and each of the nodes constituting the multi-frame corresponding to the terminal line has A multi-frame master node including multi-frame generating means for multiplexing the corresponding multi-frame number at a predetermined position of the payload of the time-division multiplex frame to generate a multi-frame of the time-division multiplex frame. Each is
When a multi-frame is received, a multi-frame number recognition means for detecting a multi-frame number from a predetermined position of a payload of a time-division multiplex frame constituting the multi-frame and recognizing an arbitrary number of multi-frames is provided. The function of the master node and the function of the multi-frame master node can be automatically determined at the same time, and there is no need to be conscious of the settings of the multi-frame master node.

According to the present invention, when all nodes except the clock master node receive the multiframe of the time division multiplexed frame, they do not hold one or more frames.
Since multi-frame transmission is performed, the delay time of the node relay time can be minimized. As a result, there is an effect that the transfer delay time in the node can be shortened.

According to the present invention, since the node priority management means for collectively managing the node priority is provided, the node priority can be set at one place, and the clock master node can be changed from one place by changing the setting. . As a result, there is an effect that the maintenance of the system can be facilitated.

According to the present invention, each of the plurality of nodes is set in advance with a node priority indicating the priority of the operation clock of the node connected in the ring, and the node priority is set at a predetermined position of the payload. A node priority multiplexing means for generating a multiplexed time division multiplex frame and transmitting the generated time division multiplex frame to another node; and a node priority set in advance for the own node and a node priority detected from the payload of the received time division multiplex frame. A node priority comparing means for comparing, and a node priority setting means for setting a node priority of the own node based on a comparison result of the node priority comparing means; When a failure occurs in the master node, the clock master node is disconnected to form a network using the above-mentioned double transmission path. Then, a failure detection signal is transmitted to other nodes connected to the network, and each of the nodes connected to the network multiplexes a node priority set in advance in its own node at a predetermined position of the payload. Is generated and transmitted to another node using the operation clock of the own node, and when the time division multiplex frame is received, the node priority comparison means detects from the node priority set in advance in the own node and the payload of the time division multiplex frame. Then, the node priority setting means transmits the node priority having a higher priority in the comparison result of the node priority comparing means to the node priority multiplexing means, and the priority is the same for a predetermined number of consecutive times. Indicates that
Since the own node is set as a new clock master node, communication between nodes other than the clock master node can be secured when the clock master node fails due to a failure, and switching of the clock master node is automatically performed. There are effects that can be performed.

According to the present invention, the clock master node includes external clock input means for inputting an external operation clock, and operation clock selection and setting means for selecting and setting an external operation clock and an operation clock of its own node. ,
A node priority control unit that sets the node priority of the own node to the highest priority when the operation clock from the outside is normal, and lowers the priority of the node priority when there is an abnormality. Therefore, even when the external clock input means is connected, the state of the clock signal from the external clock input means can be detected and the clock master node can be selected, and a more expandable and highly reliable network is provided. There is an effect that can be done.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a ring network system according to Embodiment 1 of the present invention.

FIG. 2 is a configuration diagram of an STM-1 frame used in the ring network system of the present invention.

FIG. 3 is a block diagram showing a configuration in a node of the ring network system according to the first embodiment of the present invention.

FIG. 4 is a block diagram showing a configuration of a ring network system according to Embodiment 2 of the present invention.

FIG. 5 is a block diagram showing a configuration of each node of a ring network system according to Embodiment 2 of the present invention.

FIG. 6 is a block diagram showing a configuration of a ring network system according to Embodiment 3 of the present invention.

FIG. 7 is a block diagram showing a configuration of a ring network portion of a ring network system according to a fourth embodiment of the present invention.

FIG. 8 is a diagram showing an STM-in a slave node of the ring network system according to the fourth embodiment of the present invention.
FIG. 1 is an explanatory diagram showing a frame / bus phase of a data bus.

FIG. 9 shows STM-1 in the master node of the ring network system according to Embodiment 4 of the present invention;
FIG. 3 is an explanatory diagram showing a frame / bus phase of a data bus.

FIG. 10 is a block diagram showing a configuration of a ring network system according to Embodiment 5 of the present invention.

FIG. 11 is a block diagram showing a configuration of a node to which a management device for a ring network system according to a fifth embodiment of the present invention is connected.

FIG. 12 is a block diagram showing a configuration of a ring network system according to Embodiment 6 of the present invention.

FIG. 13 is an explanatory diagram illustrating a clock master node determination operation of the ring network system according to the sixth embodiment.

FIG. 14 is a block diagram showing a configuration of a ring network system according to Embodiment 7 of the present invention.

FIG. 15 is a block diagram showing a configuration in each node of the ring network system according to the seventh embodiment.

[Explanation of symbols]

1, 1a, 1b transmission line, 2, 2 ', 2'', 2a, 2
b, 2A, 2B master node, 3, 3 ′, 3 ″, 3
a, 3b, 3A, 3B, 4, 4 ', 4'', 4b, 4B
Slave node, 5, 5a, 5b terminal line interface, 6 line transmission line, 7 TDM, 8, 8 'multi-frame generating section (multi-frame generating means), 9, 9
a Multi-frame transmitting / receiving section (multi-frame number recognizing means), 10, 10 'STM-1 frame synchronization detecting section (multi-frame number recognizing means), 11, 11' ST
M-1 termination part (multi-frame number recognition means), 12
Multi-frame synchronization detection unit (multi-frame number recognition unit), 13 delay correction frame / multi-frame pulse generation unit (multi-frame generation unit), 14, 14 'demultiplexing memory unit (multi-frame generation unit), 15 multi-frame synchronization pattern Insertion unit (multi-frame generation unit), 16, 16 'SOH addition unit (multi-frame generation unit), 17, 17' STM-1 frame synchronization pattern addition unit (multi-frame generation unit), 18, 18a
Node priority transmission / reception unit (node priority multiplexing means,
Node priority order comparing unit), 20 node priority order extracting unit, 21 and 21A node priority order setting unit (node priority order setting unit), 22 node priority order comparing unit (node priority order comparing unit), 23 and 23A clock selecting unit (Operation clock selection means), 24 clock generation units, 2
8 control information receiving unit (multiframe number recognizing unit, multiframe generating unit, node priority comparing unit, node priority setting unit), 38 node priority receiving comparing unit (node priority comparing unit), 40 management device (node Priority unit), 41 register unit (node priority setting unit, node priority management unit), 42 CP
U bus (node priority management means), 43 CPU device (node priority management means), 50 clock synchronizer (external clock input means), 51 external clock interface (external clock input means), N1 to N4 nodes.

Claims (7)

[Claims] 1. A ring network system in which a plurality of nodes are connected in a ring shape and a transmission path between the nodes uses a time division multiplex frame conforming to the SDH division multiplex system, wherein at least one of the plurality of nodes is Is connected to a terminal line that supports multi-frames of an arbitrary number of frames,
Multiframe generation for multiplexing a multiframe number corresponding to each of the constituent frames of the multiframe corresponding to the terminal line at a predetermined position of the payload of the time division multiplex frame to generate a multiframe of the time division multiplex frame A multi-frame master node provided with means, provided at each of the plurality of nodes, receiving the multi-frame, detecting the multi-frame number from a predetermined position of a time-division multiplex frame payload constituting the multi-frame. And a multi-frame number recognizing means for recognizing the multi-frame of an arbitrary number of frames. 2. A ring network system in which a plurality of nodes are connected in a ring and a transmission path between the nodes uses a time division multiplex frame conforming to the SDH division multiplex method. The node priorities indicating the priorities of the operation clocks of the connected nodes are set in advance, and the time-division multiplexed frame in which the node priorities are multiplexed at predetermined positions of the payload is generated and transmitted to other nodes. Node priority order multiplexing means, a node priority order comparing means for comparing a node priority order preset in the own node with a node priority order detected from the payload of the received time division multiplex frame, and a node priority order comparing means. Node priority setting means for setting the node priority of the own node based on the comparison result of the means. The node priority multiplexing means multiplexes a node priority set in advance at its own node at a predetermined position of the payload of the time-division multiplex frame at the start of operation, transmits the multiplexed frame at an operation clock of the own node, and The means, upon receiving the time-division multiplex frame, causes the node priority multiplexing means to transmit a node priority having a higher priority based on the comparison result of the node priority comparing means, and the priority has the same value continuously for a predetermined number of times. , A ring-type network system characterized in that its own node is a clock master node. 3. The node to which the highest-order node priority is set is connected to a terminal line corresponding to a multi-frame of an arbitrary number of frames, and corresponds to each of the frames constituting the multi-frame corresponding to the terminal line. A multi-frame master node comprising multi-frame generating means for multiplexing a multi-frame number at a predetermined position of a payload of the time-division multiplex frame to generate a multi-frame of the time-division multiplex frame, wherein each of the plurality of nodes is Receiving the multi-frame, detecting the multi-frame number from a predetermined position of the payload of the time-division multiplex frame constituting the multi-frame, and performing multi-frame number recognition means for recognizing the multi-frame of an arbitrary number of frames. 3. The ring network system according to claim 2, further comprising: . 4. The node according to claim 1, wherein all nodes except the clock master node transmit the multiframe without holding one or more frames when receiving the multiframe of the time division multiplex frame. Ring network system. 5. The ring-type network system according to claim 2, further comprising node priority management means for collectively managing the node priorities. 6. A ring-type network system in which a plurality of nodes are connected in a ring shape and the nodes are a dual transmission path using a time division multiplexing frame conforming to the SDH division multiplexing method. The node priorities indicating the priorities of the operation clocks of the nodes connected in the ring are set in advance, and a time division multiplex frame in which the node priorities are multiplexed at a predetermined position of the payload is generated to generate another node. A node priority multiplexing means for transmitting to the node, a node priority comparing means for comparing a node priority set in advance for the own node with a node priority detected from a payload of the received time division multiplex frame, Node priority setting means for setting the node priority of the own node based on the comparison result of the priority comparison means. When a failure occurs in the clock master node, the next-level node of the clock master node disconnects the clock master node to form a network using the dual transmission path, and connects to another node connected to the network. The failure detection signal is transmitted by the operation clock of the own node, and each of the nodes connected to the network multiplexes the node priority preset in the own node by the node priority multiplexing means at a predetermined position of the payload. A multiplex frame is generated and transmitted to another node with the operation clock of the own node, and when the time division multiplex frame is received, the node priority set by the node priority comparison means in advance for the own node and the time division multiplex frame And compares it with the node priority detected from the payload of the The node priority order having a higher priority in the comparison result of the node priority order comparing means is transmitted to the node priority order multiplexing means, and when the priority order shows the same value continuously for a predetermined number of times, the own node is newly assigned. A ring-type network system comprising a clock master node. 7. A clock master node comprising: an external clock input unit for inputting an external operation clock; an operation clock selection setting unit for selectively setting the external operation clock and an operation clock of the own node; And a node priority control unit that sets the node priority of the own node to the highest when the operation clock from the node is normal, and lowers the priority of the node priority when there is an abnormality. The ring network system according to claim 2 or 3, wherein: