JP2000269960A - Communication device - Google Patents

Abstract

(57) [Summary] An internal highway is shared by a plurality of line interface devices. Each low-speed line interface module is provided.
Transmits an optical signal in which an OH signal is added to an assigned time slot. The line setting unit 1 recognizes and processes each signal from the OH signal received via the multiplexer / demultiplexer 3 and the highway 7. The line setting unit 1 sends an optical signal to the highway 7 after adding an OH signal indicating the destination. Each low-speed line interface module 4 receiving the optical signal via the multiplexer / demultiplexer 3 recognizes that the signal is a signal addressed to itself from the OH signal and processes the signal.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a communication device having a plurality of line interface devices accommodating lines and a common device accommodating signals of each line, and efficiently accommodating signals of each line in the common device. It is about technology.

[0002]

2. Description of the Related Art As a communication device having a plurality of line interface devices accommodating lines and a common device accommodating signals of each line, a plurality of line interface modules (hereinafter, referred to as "LIM") as shown in FIG. A switching device, a transmission device, and the like, each of which is provided with a time division switching device (hereinafter, referred to as “TSI”) 4 and a time division switching device (hereinafter, referred to as “TSI”) 1 are known.

In such a communication apparatus, the time division switch 1 accommodates a plurality of highways 7 (hereinafter, "HW") and multiplexed signal lines 8, and each highway 7 has one line interface module. 4 are connected,
An upper line interface module 5 is connected to each multiplexed signal line 8. Also, each line interface module 4 is equipped with a plurality of line interface boards each accommodating a line 6, and the signals received by each line interface board are multiplexed for each line interface module 4, Sent to the time-division switch 1. Conversely, a signal sent from the time division switch 1 to the interface module 4 via the highway 7 is transmitted to the line interface module 4
In, the signals are separated into signals for each line interface board, sent to each line interface board, and transmitted to the line 6 from each line interface board.

[0004] In the figure, a HIM 5 is an interface module with a high-speed line 9, and its operation is the same as that of the line interface module 4 except that the line to be accommodated is the high-speed line 9.

In such a configuration, the time division switch 1 exchanges signals between lines according to the line setting from the common control device 2.

[0006]

According to the communication apparatus shown in FIG. 5, since a highway is provided for each line interface module 4 on a one-to-one basis, the number of lines that can be accommodated in the line interface module 4 is fixed. If so, the number of lines that can be accommodated in the communication device is the product of the number of highways and the number of lines that can be accommodated in the line interface module 4.

Therefore, when the number of lines that can be accommodated in the communication device is increased, it is necessary to increase the number of highways. When the number of highways is increased without changing the transmission speed of the highways, the capacity of the time-division switch also increases.
We need to make it bigger. On the other hand, when the line accommodated by the line interface module 4 is a low-speed line, and the sum of the transmission speeds of the plurality of lines accommodated in one line interface module 4 is smaller than the transmission speed of the highway, As the difference increases, the unused portion of the time slots on the highway increases, and the capacity of the time-division switch 1 is accordingly reduced.
The unused portion increases. Therefore, in such a case, the usage efficiency of the highway and the time division switch deteriorates.

[0008] Such a problem can be solved by reducing the transmission speed of the highway. However, when accommodating a large number of lines, a large number of highways are required. There are problems such as mounting problems due to an increase in the number of connections between the switch and the time-division switch, and difficulty in mounting an interface module with a high-speed line.

On the other hand, it is considered that these problems can be solved by sharing one highway in a time-sharing manner by a plurality of line interface modules. But,
For this purpose, a plurality of line interface modules are generally connected in a multi-connection form such as a bus connection to a highway composed of the same pair cable according to a general form of time division sharing of a transmission line. In this case, reflection occurs at multiple connection points due to cable loss, impedance mismatch, and the like, and if the transmission speed of the highway is increased to a practical level, normal signal transmission cannot be performed. Therefore, in such a form, it is practically difficult to share one highway in a time-sharing manner by a plurality of line interface modules.

Accordingly, the present invention provides a communication apparatus which can share a highway for transmitting and receiving signals with a common apparatus for accommodating signals of the respective lines in a time-division manner in a plurality of line interface apparatuses accommodating the lines. That is the task.

[0011]

In order to achieve the above object,
The present invention is, for example, a communication device having a plurality of line interface devices accommodating lines and a common device accommodating a signal of each line, wherein the communication device is provided corresponding to each line interface device and has a corresponding line interface. A plurality of optical transmission lines through which the device inputs and outputs optical signals, an optical highway through which the common device inputs and outputs optical signals, and a signal output from each line interface device to the plurality of optical transmission lines is combined on the optical highway. A communication device, comprising: a multiplexing / demultiplexing unit that transmits a signal output from the common device to the optical highway by transmitting the signal to the optical transmission line.

According to such a communication device, a plurality of line interface devices are multi-connected to the highway configured as an optical highway via the multiplexing / demultiplexing means. The transmission speed of the highway at which normal signal transmission can be performed is not limited to a low level due to reflection at a multi-connection point or the like. Therefore, at a practical level, it is possible to realize sharing of a highway by a plurality of line interface devices in a time-division manner.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment of a communication device according to the present invention will be described.

FIG. 1 shows a configuration of a communication apparatus according to the present embodiment.

In the figure, reference numeral 1 denotes a line setting unit (TSI),
A highway 7 composed of a pair of up and down optical fiber transmission lines and one or a plurality of up and down paired multiplexed signal lines 8 are accommodated. Reference numeral 2 denotes a common control device.

Further, the present communication apparatus comprises, for each highway 7, a pair of up / down optical multiplexer / demultiplexer 3 and a plurality of low-speed lines 6.
Low-speed line interface module (LI
M) 4, an optical multiplexer / demultiplexer 3, and each low-speed line interface module (LIM) 4; a pair of optical transmission lines 7-1 to 7-
n. Further, each multiplexed signal line 8 has a high-speed line interface module (HIM) 5 for accommodating a high-speed high-speed line 9.

Next, FIG. 2 shows the internal configuration of the low-speed line interface module LIM4.

In the drawing, 4-1-1 to 4-1-n denote low-speed line interface boards LIF, 4 which accommodate one low-speed line.
-2 is a demultiplexing unit MPX / DMPX, 4-3 is an OH identification unit, 4-7 is an OH addition unit, 4-4 is an optical reception interface unit, 4-5 is an optical transmission unit, and 4-6 is transmission phase control. Part 4,
Reference numeral -8 denotes a transmission / reception time slot control unit, and reference numeral 4-9 denotes a clock generation unit.

FIG. 3 shows an internal configuration of the line setting unit TSI1.

In the figure, 1-1 is an optical transmitting section, 1-2 is an OH adding section, 1-3 is a time division switch TSW, 1-5 is an OH identifying section, 1-6 is an optical receiving section, 1-4 Is the clock generator PG
It is.

In FIGS. 2 and 3, of the optical input / output transmission lines connected to the LIM 4 via the multiplexer / demultiplexer 3, the downstream one is 7-IB and the upstream one is 7-IB. Indicated by IF.

The operation of such a communication device will be described below.

Here, as an example, the communication apparatus performs time-division multiplexing on signals received from a plurality of low-speed lines accommodated in each low-speed line interface module LIM4 on a high-speed line accommodated in the high-speed line interface module 5 and transmits the signals. Then, it separates the time-division multiplexed signal received from the high-speed line 9 accommodated by the high-speed line interface module 5 and addressed to each low-speed line, and transmits the signal from each of the plurality of low-speed lines accommodated by each low-speed line interface module LIM4. The operation will be described assuming that the apparatus is an apparatus.

First, a time-division multiplexed signal addressed to each low-speed line received from the high-speed line accommodated by the high-speed line interface module 5 is separated and transmitted from each of the plurality of low-speed lines accommodated by each low-speed line interface module LIM4. The operation to be performed will be described.

The high-speed line interface module 5
A signal received from the accommodated high-speed line 9 is transmitted to the line setting unit TSI1 via the multiplexed signal line 8. The line setting unit TSI1 converts the received signal into a time-division switch TSW1.
At -3, the signal is separated into signals for each highway 7 to be sent, and sent to the OH adding unit 1-2 corresponding to each highway.
As shown in FIG. 4A, the OH adding unit 1-2 assigns, to each of the signals for each low-speed line interface LIM4 to which the signal included in the received signal is to be sent, the identification number of the LIM4 and the number of bytes of the signal. The pattern indicating the signal position is OH
The signal added as a signal is converted into an optical signal by the optical transmitting unit 1-1 and transmitted to the highway 7-IB. Here, FIG.
As shown in (a), the signal transmitted from the line setting unit TSI1 to the highway 5 is transmitted to each low-speed line interface LIM.
A signal string to which a signal to which every four OH signals are added may be densely continuous.

The signal sent to the highway 7-IB is
The light is split by the multiplexer / demultiplexer 3 and relayed to the optical transmission lines 7-1 to 7-n. In each low-speed line interface module LIM connected to each of the optical transmission lines 7-1 to 7-n, this signal is converted into an electric signal by the optical receiving unit 4-4, and the OH identification unit 4-3
Send to If the identification number included in the OH signal of the received signal is the identification number of its own LIM 4, the OH identification unit 4-3 removes the OH signal and sends it to the DMPX unit 4-2. This is performed using a pattern indicating the number of bytes and the signal position of the signal included in the signal. Demultiplexing unit M
The PX / DMPX 4-2 converts the received signal into a low-speed interface board LIF4
-1-1 to 4-1-n, the low-speed interface board LI to which the separated signal is to be sent.
F4-1-1 to 4-1-n. The low-speed interface boards LIF4-1-1 to 4-1-n perform processing such as converting the received signal into a frame format compatible with the low-speed line interface, and transmit the signal to the low-speed line.

Next, the operation of transmitting signals received from a plurality of low-speed lines accommodated by each low-speed line interface module LIM4 and time-division multiplexed on the high-speed lines accommodated by the high-speed line interface module HIM5 will be described.

Each low-speed line interface board LIF4-1 to 4-1 of each low-speed line interface module 4
n converts a signal received from the accommodated low-speed line into a signal format for the inside of the communication device, and sends it to the demultiplexing unit MPX / DMPX4-2. MPX / DMPX unit 4
-2 indicates each low-speed line interface board LIF4-1
4-1n are time-division multiplexed, and
It is sent to the H adding section 4-7. The OH adding unit 4-7 adds, to the optical transmission unit 4-4, a signal obtained by adding, as an OH signal, a pattern indicating the identification number of the LIM 4, the number of bytes of the signal, and the signal position to the time-division multiplexed signal. Into L
The signal is transmitted to the optical transmission lines 7-1 to 7-n connected to the IM4.
During periods other than the signal transmission period, the optical transmission unit 4-4 is controlled so as not to transmit an optical signal.

The optical signals transmitted from the low-speed line interface modules LIM4 to the optical transmission lines 7-1 to 7-n are multiplexed by the multiplexer / demultiplexer 3 and transmitted to the highway 7-IF.

Here, the transmission timing of the optical signal from each low-speed line interface module LIM4 to the optical transmission lines 7-1 to 7-n is determined by the transmission / reception TS control 4-8 and the transmission phase control 4-6. MPX / DMPX4-
2. This is performed by controlling the optical transmission unit 4-4. Send T
The S control 4-8 and the transmission phase control 4-6 are provided by the common control device 2
The transmission timing is controlled in accordance with the setting from. Specifically, each low-speed line interface module LIM4 transmits an optical signal to a different time slot according to the setting from the common control device 2. The time slot at which each low-speed line interface module LIM4 sends out an optical signal is shown in FIG.
As shown by the signal on the IF, the common control device 2 sets each low-speed line interface module LIM4 such that a non-signal guard time for a certain pit period occurs between each time slot. Further, the common control device 2 allocates a time slot to each low-speed interface module LIM4 by the sum of the transmission speed of the low-speed line accommodated by each low-speed interface module LIM4. Therefore, the sum of the transmission speeds of the low-speed lines accommodated by each low-speed interface module LIM4 does not have to be the same.

The signal transmitted on the highway 7-IF is transmitted to the optical receiving unit 1-1 in the line setting unit TSI1.
After being received by the OH identification unit 1-
Sent to 5. The OH identification unit 1-5 recognizes the signal transmitted by each LIM 4 from the OH signal of the signal received as the burst signal, removes the OH signal, and then switches the switch unit TS.
Hand over to Wl-3. The time division switch TSWl-3 time multiplexes each received signal for each multiplexed signal line 8 to which a signal is to be sent, and sends the signal to the high-speed line interface module HIM5 via the multiplexed signal line 8 to which the signal is to be sent. The high-speed line interface module HIM5 performs processing such as converting the received signal into a frame format that matches the high-speed line interface, and transmits the signal to the high-speed line.

As described above, according to the present communication apparatus, a plurality of low-speed line interface modules are multi-connected to a highway configured as an optical transmission line via a multiplexer / demultiplexer, so that cable loss and the like are reduced. Due to reflection at multiple connection points due to impedance mismatch, etc.
The transmission speed of the highway capable of normal signal transmission is not limited to an impractically low speed. Therefore, at a practical level, it is possible to realize sharing of a highway in a time-sharing manner by a plurality of low-speed line interface modules.

Further, in the present communication device, the sharing of the highway by the plurality of low-speed line interface modules is performed in a time-sharing manner, and the transmission of the signal from the low-speed line interface module to the highway uses a time slot for each low-speed interface module. Although this is realized by the fixed allocation, the signal transmission from the highway to the highway of the line setting unit TSI1 is realized without the time slot being fixedly allocated to each low-speed interface module. Therefore, it is only necessary to control the transmission timing of the low-speed line interface module as shown in FIG. 4B, and it is necessary to particularly control the transmission timing of each low-speed line interface module in the line setting unit TSI1. There is no. Therefore, with a simple configuration and control, it is possible to realize time-sharing sharing of a highway by a plurality of low-speed line interface modules.

Further, the line setting unit TSI1 recognizes the signal from each low-speed line interface module from the OH signal, and determines the signal transmission timing from the low-speed line interface module to the highway on each high-speed line interface. Since a fixed guard time is generated between the signals from the modules, even if the transmission timing of each low-speed interface module is slightly shifted, there is no overlap between the signals,
The signal from each low-speed line interface module can be recognized by the line setting unit TSI1 without any trouble. Conversely, according to the present communication device, fine control of the transmission timing of each low-speed interface module can be eliminated.

Now, in the present communication device as described above,
Each unit in the low-speed line interface module 4, the high-speed line interface module 5, and the line setting unit TSI1 receives various clocks (such as a bit clock and a frame clock) generated by the common control device 2 from a clock extracted from a transmission line or a predetermined external clock. It is supplied and operates in synchronization with this clock. For example, in the low-speed line interface module 4 and the line setting unit TSI1, the clock generation units PG4-9 and PG4 receive the clock from the common control device 2 and generate the clock according to the clock. Setting section TSI1
And distributes them as operation clocks to each part.

Therefore, according to the present communication apparatus, even if a failure occurs in a certain low-speed line, the operation of the other low-speed interface module is not hindered. Or cause a low-speed interface module accommodating a failed low-speed line to execute a predetermined failure process. That is, for example, if the low-speed line interface module 4 is operated in synchronization with the clock extracted from the signal received from the highway, if a failure occurs in the receiving system from the highway, the low-speed line interface module 4 performs fault processing and the like. Not only cannot be performed, but also the signal transmission timing of the low-speed line interface module 4 to the highway 5 deviates from the original transmission timing, and the signal transmission timing of the other low-speed line interface module 4 to the highway 5 And the signal transmitted from the other low-speed line interface module 4
SI1 may not be recognized. However, according to the present communication device, such a problem can be avoided because the low-speed line interface module 4 and the line setting unit TSI1 operate according to the clock from the common control device 2.

Further, according to the present communication apparatus, since each low-speed interface module is connected to the highway using the optical transmission line using the optical multiplexer / demultiplexer, it affects other low-speed line interface devices in use. There is also an advantage that the low-speed interface module can be added without the need.

In the above embodiment, the highway 7 and the optical transmission paths 7-1 to 7-n may be one bidirectional transmission path.

[0039]

As described above, according to the present invention, a plurality of line interface devices accommodating a line share a highway for transmitting and receiving signals with a common device accommodating a signal of each line in a time division manner. It is possible to provide a communication device capable of performing the following.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration of a communication device according to the present invention.

FIG. 2 is a block diagram showing an internal configuration of a low-speed line interface module of the communication device according to the present invention.

FIG. 3 is a block diagram showing an internal configuration of a line setting unit of the communication device according to the present invention.

FIG. 4 is a diagram illustrating how signals are multiplexed on a highway of the communication device according to the present invention.

FIG. 5 is a block diagram showing a configuration of a conventional communication device.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Line setting part (TSI) 2 Common control device 3 Optical multiplexer / demultiplexer 4 Low-speed line interface module (LIM) 5 High-speed line interface module (HIM) 6 Low-speed line 7 Highway 7-1 to 7-n Optical transmission line 8 Multiplexing Signal line 9 Upper high-speed line 4-1-1 to 4-1-n Low-speed line interface board (LIF) 4-2 Demultiplexer MPX / DMPX 4-3 OH identification unit 4-4 Optical reception interface unit 4-5 Optical Transmission unit 4-6 Transmission phase control unit 4-7 OH addition unit 4-8 Transmission / reception time slot control unit 4-9 Clock generation unit (PG) 1-1 Optical transmission unit 1-2 OH addition unit 1-3 Time division switch (TSW) 1-4 Clock generator (PG) 115 OH discriminator 1-6 Optical receiver

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H04L 7/04 H04Q 11/04 B H04Q 11/04 F term (Reference) 5K002 AA01 AA03 BA05 BA06 DA02 DA10 DA13 DA42 FA01 5K028 AA06 AA11 BB08 CC02 CC05 DD07 KK01 LL02 MM08 MM16 NN33 RR01 SS02 TT01 5K030 GA01 GA04 HB15 HB16 JA01 JL03 KA13 LA15 5K047 AA15 BB02 CC02 GG03 GG06 LL06 5K0 CB10 CB03 DA03CB03

Claims (4)

[Claims] A communication device having a plurality of line interface devices accommodating lines and a common device accommodating a signal of each line, wherein the communication device is provided corresponding to each line interface device and has a corresponding line interface device. A plurality of optical transmission lines for inputting and outputting optical signals, an optical highway for inputting and outputting optical signals to and from a common device, and combining the signals output from each line interface device on the plurality of optical transmission lines on the optical highway. And a multiplexing / demultiplexing means for transmitting and outputting the signal output from the common device to the optical highway to the optical transmission line. 2. The communication device according to claim 1, wherein each of the line interface devices supports an optical signal in a mutually different period with a period during which no line interface device outputs an optical signal. A communication device for outputting the signal to an optical transmission line. 3. The communication device according to claim 1, wherein the common device adds, to the optical highway, identification information for designating a destination line interface to a signal to be sent to each line interface device. A signal is output as an optical signal, and each of the line interface devices includes, among the internal signals represented by the optical signals received from the corresponding optical transmission lines, a signal included in the internal signal including identification information specifying the own line interface device. Receiving and processing as a signal addressed to the own line interface device. 4. The communication device according to claim 1, wherein at least the plurality of line interface devices transmit a clock signal including a clock component for synchronizing the operation of the plurality of line interface devices to the highway. And a control unit for distributing via a transmission path independent of the communication device.