JP3149490B2 - Loop network system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a loop network system, and more particularly to a loop network system using an SDH network for a part of a transmission path between a master node and a slave node or a transmission path between slave nodes.

[0002]

2. Description of the Related Art Conventionally, this type of loop network system is used for data transmission in a loop in a loop network system in which one master node and a plurality of slave nodes are connected in a loop via a transmission line. One frame = 4 or 24 frames, one frame = (STM-1 frame composed of 270 × 9 time slots), and the H4 pointer in the POH of VC4 in the STM-1 frame is synchronized with the multiframe. Pattern, a time division multiplexed frame using the C4 time slot in the STM-1 frame as a service channel, and the master node generates the time division multiplexed frame and time multiplexes the line data connected to its own node. After dropping and inserting into the service channel of the multiplex frame, the next thread And sends it to the nodes send out.

Further, the slave node is subordinately synchronized with the received time division multiplex frame, drops and inserts the line data connected to the own node into the service channel of the time division multiplex frame, and then transmits the next slave node via the transmission path. Or sending to the master node, and the master node further
Loop delay correction is performed between the received time-division multiplex frame and the time-division multiplex frame generated by the master node itself, and the transmission path between the master node and the slave node or a part of the transmission path between the slave node and the slave node is S
The DH network was used.

[0004]

In the above-described loop network system, the H4 pointer in the POH of the VC4 in the STM-1 frame is used as a multi-frame synchronization pattern. Therefore, one multi-frame defined by CCITT = 4 Frame or one multi-frame = 24
There is a disadvantage that only a multi-frame configuration can be realized.

An object of the present invention is to provide a multi-frame having an STM-1 frame as a basic frame = 2.5 msec,
An object of the present invention is to provide a loop network system using a time division multiplex frame suitable for accommodating a multimedia interface in which one frame = 125 μsec.

[0006]

In order to achieve the above object, in a loop network system according to the present invention, one master node, a plurality of slave nodes, and
In a loop network system in which the DH connection nodes (S, R) are connected in a loop via a transmission path, the number of frames used for data transmission in the loop is 1 multiframe = 20 frames, 1 frame = (270 × 9 time slots (STM-1 frame), the ST
Any one time slot in C4 in the M-1 frame is a multi-frame synchronization pattern, and any number of time slots in C4 is a housekeeping channel.
4, the master node generates the time-division multiplex frame and branches the line data connected to the own node to the service channel of the time-division multiplex frame. After the insertion, the data is transmitted to the next slave node via the transmission path, and the slave node is subordinately synchronized with the received time division multiplex frame, and drops and inserts the line data connected to the own node into the service channel of the time division multiplex frame. And then send it to the next slave node or SDH connection node or master node via the transmission path, and the master node
A loop delay correction for transferring received C4 data to transmission C4 data in frame units or multiframe units between the received time division multiplex frame and the time division multiplex frame generated by the master node itself, An SDH network is used for a transmission path between a slave node and a part of a transmission path between a slave node and a slave node via an SDH connection node.

[0007] The SDH connection node S terminates the received time division multiplex frame and transmits the STM-1 to the SDH network.
Transmitted as a frame, and the SDH connection node R
The STM-1 frame of the DH network is terminated and sent to the next slave node or SDH connection node S or master node as a time division multiplex frame.

[0008]

A loop network system using an SDH network as a part of a transmission line is constructed by using a time division multiplex frame suitable for accommodating a multimedia interface having an STM-1 frame as a basic frame.

[0009]

Next, the present invention will be described with reference to the drawings.

FIG. 1A is an overall configuration diagram showing one embodiment of the present invention, FIG. 1B is a frame configuration diagram used in one embodiment of the present invention, and FIG. 2 is an embodiment of the present invention. FIG. 3 is a block diagram of a master node used in the example, and FIG. 3 is a block diagram of a slave node used in one embodiment of the present invention.

Referring to FIG. 1A, the present invention has one master node 101 and a plurality of slave nodes 102 and 1.
02... And SDH connection nodes (S, R) 105, 106
Is intended for a loop network system connected in a loop via the transmission line 103. Reference numeral 104 denotes an SDH network.

The frames used for data transmission in the loop are: 1 multiframe = 20 frames, 1 frame =
(STM-1 frame consisting of 270 × 9 time slots), an arbitrary time slot in C4 in the STM-1 frame is set to a multi-frame synchronization pattern,
Is a time-division multiplexed frame with an arbitrary number of time slots in a housekeeping channel and a remaining time slot in the C4 as a service channel.

The master node 101 generates the time-division multiplex frame, branches and inserts the line data connected to the own node into the service channel of the time-division multiplex frame, and sends it out to the next slave node via the transmission line 103. I do.

The slave node 102 is subordinately synchronized with the received time division multiplex frame, drops and inserts the line data connected to its own node into the service channel of the time division multiplex frame, and then transmits the next slave node via the transmission line 103. Alternatively, the packet is sent to the SDH connection node or the master node.

[0015] The SDH connection node S105 terminates the received time division multiplex frame and sends the STM-multiplexed frame to the SDH network 104.
Transmitted as one frame.

The SDH connection node R106 is connected to the SDH network 1
04, and terminates the next slave node or SDH connection node S as a time division multiplex frame.
Or send it to the master node.

The master node 101 loops between the received time-division multiplex frame and the time-division multiplex frame generated by the master node itself to transfer received C4 data to transmission C4 data in frame units or multiframe units. Perform delay correction.

The master node 101 and the slave node 10
2 or the slave node 102
SDH is part of the transmission path between the
The SDH network is used via the connection node.

The configuration of the master node 101 will be described. As shown in FIG. 2, the clock generator 1 generates a master clock MCK of the loop network system and sends it to the frame pulse / multiframe pulse generator 2.

The frame pulse / multi-frame pulse generator 2 converts the master clock MCK to the transmission clock S
C, a transmission frame pulse SFP indicating the position of the frame synchronization pattern of the STM-1 frame, an envelope signal SEV indicating the position of VC4, and a transmission multi-frame pulse indicating the position of the multi-frame synchronization pattern, which is an arbitrary time slot in C4. An SMFP is generated and sent to a first input of the loop delay correction unit 3.

The STM-1 frame synchronization detector 11
Extracts the reception clock RC from the reception data RD from the transmission line 103, detects the STM-1 frame synchronization, generates the reception frame pulse RFP, and outputs the RD, R
C and RFP are sent to the SOH termination unit 12.

The SOH terminator 12 uses the RD, RC, and RFP from the STM-1 frame synchronization detector 11 to output the SOH
Is terminated. In particular, an envelope signal REV indicating the position of VC4 is generated by the AU pointer in the SOH in the RD, and the REV is transmitted to the VC4 terminating unit 13 together with the RD, RC, and RFP.

The VC4 terminating unit 13 sends RD, RC, RFP, and REV from the SOH terminating unit 12 to the multiframe synchronization detecting unit 14 and terminates the POH of the VC4.

The multi-frame synchronization detecting section 14 is provided with a VC4
RD, RC, RFP, REV from terminal unit 13
A multi-frame synchronization is detected from the multi-frame synchronization pattern in C4 in D to generate a reception multi-frame pulse, and RD, RC, RFP, REV, and RMFP are sent to the second input of the loop delay correction unit 3. .

The loop delay correction unit 3 outputs the frame pulse /
SC, SFP, S from multi-frame pulse generator 2
After the EV, SMFP and RD, RC, REV, RMFP from the multi-frame synchronization detector 14 perform loop delay correction for C4, the transmission data S after delay correction
D, SC, SF, SEV, and SMFP are sent to the add / drop unit 21.

The add / drop unit 21 receives the SD, SC, SFP, SEV, and SMFP from the loop delay correction unit 3,
The data of the service channel connection unit 22 is dropped and inserted into the service channel in the C4 in the SD, and the data of the housekeeping channel connection unit 23 is dropped and inserted in the housekeeping channel in the C4. It is sent to the synchronization pattern insertion unit 15.

The multi-frame synchronization pattern insertion unit 15
SD, SC, SFP, SEV, S from the add / drop unit 21
The MFP receives the MFP, inserts the multi-frame synchronization pattern into the C4 multi-frame synchronization pattern time slot in the SD based on the SMFP, and sends the SD, S
C, SFP and SEV are transmitted.

The SD, SC, SFP, and SEV signals are VC
4 the POH is added by the generation unit 16, the SOH is added by the SOH addition unit 17, the frame synchronization pattern is added by the STM-1 frame synchronization pattern addition unit 18, and the transmission data S is added.
D is transmitted to the slave node via the transmission line 103.

With the above configuration, the master node is
(B) One multi-frame = 20 frames, 1 frame = (STM composed of 270 × 9 time slots)
-1 frame), an arbitrary time slot in C4 in the STM-1 frame is set to a multi-frame synchronization pattern,
A time-division multiplexing frame is generated by using an arbitrary number of time slots in the C4 as a housekeeping channel and the remaining time slots in the C4 as a service channel, and time-division multiplexing the line data connected to the own node. After dropping and inserting the frame into the service channel, the frame is sent to the next slave node via the transmission path, and the loop delay is corrected between the received time division multiplex frame and the time division multiplex frame generated by the master node itself. Like that.

Next, the configuration of the slave node 102 will be described.

The STM-1 frame synchronization detecting section 11 converts the received data RD from the transmission
At the same time as detecting the STM-1 frame synchronization to generate a received frame pulse RFP,
The FP is sent to the SOH termination unit 12.

The SOH terminator 12 uses the RD, RC, and RFP from the STM-1 frame synchronization detector 11 to output the SOH
Is terminated. In particular, an envelope signal REV indicating the position of VC4 is generated by the AU pointer in the SOH in the RD, and the REV is transmitted to the VC4 terminating unit 13 together with the RD, RC, and RFP.

The VC4 terminating unit 13 sends RD, RC, RFP, and REV from the SOH terminating unit 12 to the multi-frame synchronization detecting unit 14 and terminates the VC4 POH.

The multi-frame synchronization detecting section 14 is provided with a VC4
RD, RC, RFP, REV from terminal unit 13
Multi-frame synchronization is detected from the multi-frame synchronization pattern in C4 in D to generate a received multi-frame pulse, and RD, RC, RFP, REV, and RMFP are sent to the drop-and-insert unit 21.

The drop-and-insert unit 21 receives the RD, RC, RFP, REV, and PMFP of the multiframe synchronization detection unit 14 and drops and inserts the data of the service channel connection unit 22 into the service channel in C4 in the RD. And also C
4, the data of the housekeeping channel connection unit 23 is dropped and inserted into the housekeeping channel in 4, and a signal resulting from the drop and insertion is transmitted data SD and transmission clock S.
C, transmission frame pulse SFP, transmission envelope S
EV, which is transmitted to the multi-frame synchronization pattern 15 as a transmission multi-frame pulse SMFP.

The multi-frame synchronization pattern insertion unit 15
SD, SC, SFP, SEV, S from the add / drop unit 21
The MFP receives the MFP, inserts the multi-frame synchronization pattern into the C4 multi-frame synchronization pattern time slot in the SD based on the SMFP, and sends the SD, S
C, SFP and SEV are transmitted.

The SD, SC, SFP and SEV signals are VC
4 the POH is added by the generation unit 16, the SOH is added by the SOH addition unit 17, the frame synchronization pattern is added by the STM-1 frame synchronization pattern addition unit 18, and the transmission data S is added.
D is transmitted to the next slave node or master node via the transmission path 103.

With the above configuration, the slave node is
(B) One multi-frame = 20 frames, 1 frame = (STM composed of 270 × 9 time slots)
-1 frame), an arbitrary time slot in C4 in the STM-1 frame is set to a multi-frame synchronization pattern,
An arbitrary number of time slots in the C4 are house-keeping channels, and the remaining time slots in the C4 are service channels. After dropping and inserting into the service channel of the multiplex frame, the signal is transmitted to the next slave node or master node via the transmission path.

In a loop network system in which one master node and a plurality of slave nodes are connected in a loop via a transmission line as described above, transmission between the master node and the slave node or transmission between the slave node and the slave node is performed. An SDH network is used for part of the road.

[0040]

As described above, according to the present invention, it is possible to realize a time division multiplexed frame in which 1 multiframe = 20 frames and 1 frame = (STM-1 frame composed of 270 × 9 time slots). There is an effect that can be.

That is, it is possible to realize a loop network system using a time-division multiplex frame suitable for accommodating a multimedia interface in which one multi-frame = 2.5 msec and one frame = 125 μsec using an STM-1 frame as a basic frame. effective.

[Brief description of the drawings]

FIG. 1A is an overall configuration diagram showing one embodiment of the present invention, and FIG. 1B is a frame configuration diagram used in one embodiment of the present invention.

FIG. 2 is a block diagram of a master node used in one embodiment of the present invention.

FIG. 3 is a block diagram of a slave node used in one embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Clock generation part 2 Frame pulse / multiframe pulse generation part 3 Loop delay correction part 11 STM-1 frame synchronization detection part 12 SOH termination part 13 VC4 termination part 14 Multiframe synchronization detection part 15 Multiframe synchronization pattern insertion part 16 VC4 generation Unit 17 SOH addition unit 18 STM-1 frame synchronization pattern addition unit 21 Drop and insertion unit 22 Service channel connection unit 23 Housekeeping channel connection unit 101 Master node 102 Slave node 103 Transmission path 104 SDH network 105 SDH connection node S 106 SDH connection node R

Claims (2)

(57) [Claims] 1. A loop network system in which one master node, a plurality of slave nodes, and SDH connection nodes (S, R) are connected in a loop via a transmission line, and are used for data transmission in the loop. 1 frame = 20 frames, 1 frame = (STM-1 frame composed of 270 × 9 time slots), and any one time slot in C4 in the STM-1 frame is synchronized with the multiframe. The pattern, a time-division multiplex frame using an arbitrary number of time slots in the C4 as a housekeeping channel and the remaining time slots in the C4 as a service channel, and the master node generates the time-division multiplex frame. Dropped the line data connected to its own node into the service channel of the time division multiplex frame To the next slave node via the transmission path, and the slave node synchronizes dependently on the received time-division multiplex frame, and after dropping and inserting the line data connected to the own node into the service channel of the time-division multiplex frame, The master node transmits the received C4 data between the received time-division multiplex frame and the time-division multiplex frame generated by the master node itself, to the next slave node, SDH connection node, or master node via the transmission path. A loop delay correction for changing the transmission C4 data in frame units or multiframe units is performed, and a part of a transmission path between a master node and a slave node or a part of a transmission path between slave nodes and a slave node is connected via an SDH connection node. A loop network system using an SDH network. 2. The SDH connection node S terminates the received time-division multiplex frame and sends it to the SDH network as an STM-1 frame. The SDH connection node R terminates the STM-1 frame of the SDH network. 2. The loop network system according to claim 1, wherein the loop network system transmits the time-division multiplex frame to the next slave node, SDH connection node S, or master node.