JP2000269915A - Stm switch - Google Patents

Abstract

PROBLEM TO BE SOLVED: To avoid wasting of functions of an external device when of selecting a fixed assignment system by making number of links assigned to each external device variable, in matching with an interface specification with the external device with respect to an synchronous transfer mode(STM) switch used for an exchange. SOLUTION: An incoming link edit section 2 is placed between an STM switch module 1 and an input side external device at an incoming link side, the STM switch module 1 and the incoming link edit section 2 are interconnected by M-sets of incoming links, the incoming link edit section 2, and a plurality of the input side external devices are interconnected by the M-sets of incoming link, the incoming link edit section 2 is provided with M-sets of selectors corresponding to each link number of the incoming links, and each selector respectively receives an incoming link with a corresponding link number from a plurality of the input side external devices.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an STM (synchronous transfer mode) switch used in an exchange.

[0002]

2. Description of the Related Art FIG. 24 shows a conventional example of an STM switch. This STM switch has 6 incoming links and 6 outgoing links.
It has a 4 link x 64 link configuration. At the center is an STM that switches 64 links x 64 links
This is the switch module 1. Data to be actually switched is input from outside the STM switch, and data after switching is output to the outside of the STM switch. The external device performs the interface on the STM switch side. In the example of FIG. 24, this external device is provided with eight external devices inf0 to inf7 on the input side and eight external devices inf'0 to inf'7 on the output side. Since the STM switch performs switching of 64 links × 64 links, each of the external devices on the input side and the output side has eight links on the STM switch module 1 side.
It will be assigned for each link.

The incoming link # of the STM switch module 1
0 to # 63 and outgoing links # 0 to # 63
Each link is composed of 512 time slots TS0 to TS511, one time slot corresponds to 64 kbps, and thus one link corresponds to 32.768 Mbps.
Accordingly, since one external device is assigned eight links of the STM switch module 1,
This means that data corresponding to 62.144 Mbps is being processed.

On the other hand, in the prior art shown in FIG. 24, the external devices inf0 to inf7 on the input side and the external devices inf'0 to inf'7 on the output side all have the same configuration, and each of the external devices is 524.288 Mbps. Data processing capacity, so that up to 16 links on the STM switch module 1 side can be assigned to one external device, and it is possible to respond to changes in external interface specifications. It is like that.

Here, there are various types of interface specifications with external devices, and various types of external devices exist according to the specifications.

For example, in the case of interfacing with an external device by the SDH method, in the example of FIG.
2. Transfer data equivalent to 144 Mbps to two external STM1
It will be mapped to a line (line). That is,
The STM1 line has a speed of 155.52 Mbps,
Excluding various overheads, the bit rate of the payload is 131.072 Mbps, which is 262.144 Mbps for two STM1 lines, while the external device has 8 links (26 links) on the STM switch module 1 side.
2.144 Mbps data amount)
The number of STM1 lines accommodated in the external device is two.

However, since the data processing capability of the external device is 522.288 Mbps at the maximum as described above,
Despite the physical size of the current STM1 line interface circuit (accommodating two STM1 lines), originally at least four STMs per external device
It should be able to accommodate the TM1 line.

When the external device is interfaced by the PCM method, the number of links on the STM switch module 1 side of the external device is eight, so that the number of links is 262.144 Mbps.
In this case, since the PCM30 system line has a bit rate equivalent to 2.048 Mbps per line, the number of PCM30 system lines to be mapped is 128 in total.
It becomes a book.

However, due to the physical size of the cable for the actual PCM30 system line, the number of PCM30 system lines that can be accommodated per external device is at most about 16, and as many as 128 PCM30 system lines. It is impossible to accommodate the line.

[0010]

SUMMARY OF THE INVENTION As described above,
In the current system in which a fixed number of links are allocated to the external device, there is waste in the processing capability of the external device depending on the interface specifications with the external device.

For example, when interfacing with an external device by the SDH method, the external device can accommodate at least four STM1 lines (corresponding to a data amount of 524.288 Mbps in total) at present. ST
Since the interface with the M switch module 1 has 8 links (corresponding to 262.144 Mbps in total), 2
It can accommodate only one STM1 line (corresponding to 262.144 Mbps in total), and thus has an image in which the functions of the external device are reduced by half.

When the external device is interfaced with the PCM30 system line, the external device accommodates at most 16 PCM30 system lines (corresponding to 31.768 Mbps and corresponding to one link on the STM switch module 1 side). Can not. Here, 262.144 Mbps on the interface with the STM switch module 1
Despite the assignment of s (for 8 links), only 1/8 of the assignment can be used effectively, and the function of the external device (524.288Mbps data processing capacity) is 1 / It becomes an image in which only 16 are effectively used.

[0013] The present invention has been made in view of such a problem, and is designed so that an external device only needs to have a processing capability according to the number of links allocated to the external device, in other words, in accordance with an interface specification with the external device. An object of the present invention is to make the number of links allocated to each external device variable so as to avoid wasting the functions of the external device in the fixed allocation method.

[0014]

First, an STM switch to which the present invention is applied includes an STM switch module having an incoming link and an outgoing link of M × N (where M and N are integers of 2 or more). An STM switch comprising: a plurality of input-side external devices for interfacing the STM switch module with the outside on the input side; and a plurality of output-side external devices for interfacing the STM switch module with the outside on the output side. It is.

[0015] In order to solve the above problems, the present invention provides:
In the above-described STM switch, the number of links allocated to the external device is made variable in accordance with the interface specifications with the external device, so that the processing capacity of the external device is not wasted. There are the following methods for making the number of assigned links variable. (1) All links are virtually allocated to each external device. (2) A certain number of external device interfaces are grouped in (1), and a number of links are assigned to each group. (3) The STM switch module and each external device are connected in a bus format.

In order to realize the above (1), on the incoming link side, an incoming link editing unit is arranged between the STM switch module and the external device on the input side, and the STM switch module and the incoming link editing unit are arranged. Units are connected by M incoming links, and the incoming link editing unit and the plurality of input side external devices are connected by M incoming links, respectively, and the incoming link editing unit is provided with incoming links. M corresponding to each link number
And a plurality of selectors, each of which receives an incoming link of a corresponding link number from the plurality of input-side external devices. In this STM switch, it is possible to control which input external device is to be selected by a selector corresponding to each input link number. Therefore, the input external device does not need to be fixedly assigned, and the input external device is not required. Each device can be provided with a processing capacity corresponding to the number of assigned incoming links, and the functions of the input-side external device can be used effectively.

On the outgoing link side, an outgoing link editing unit is disposed between the STM switch module and the output side external device, and N outgoing links are provided between the STM switch module and the outgoing link editing unit. The outgoing link editing unit and the plurality of output-side external devices are respectively connected by N outgoing links, and each of the plurality of output-side external devices has a link number of each outgoing link. N selectors are provided so as to correspond to N.
A required one of the outgoing links of the book is configured to be input. In this STM switch, the output-side external device can control which output data is selected from which output link by a selector corresponding to each output link number. Therefore, the output-side external device does not have to be fixedly assigned. Each output-side external device can be provided with a processing capability corresponding to the number of assigned outgoing links, and the functions of the output-side external device can be used effectively.

Further, in order to realize the above (2), on the incoming link side of the STM switch, the M incoming links of the STM switch module are divided into a plurality of groups, and an incoming link editing unit is provided for each group. And each incoming link editing unit is configured to connect an incoming link to an input external device accommodated by the incoming link number assigned to each incoming link editing unit. As a result, the number of incoming links connecting the input-side external device and the incoming link editing unit can be reduced to a grouped number, and the total number of incoming links can be reduced.

On the outgoing link side of the STM switch, N outgoing links of the STM switch module are divided into a plurality of groups, and an outgoing link editing unit is provided for each group, and each outgoing link editing unit is provided with an outgoing link editing unit. An outgoing link is connected to an output-side external device accommodated by the outgoing link number assigned to the link editing unit. As a result, the number of outgoing links connecting the output side external device and the outgoing link editing unit can be reduced to a grouped number, and the total number of outgoing links can be reduced.

In order to reduce the number of incoming links in the STM switch, a plurality of incoming links connected between the incoming link editing unit and the input side external device are replaced by common incoming links, and The input-side external device can be configured to time-division multiplex the input data of the incoming link allocated to the own station and send it to the incoming link editing unit via the common incoming link. it can. Thereby, the number of incoming links connecting between the input-side external device and the incoming link editing unit is reduced to 1
Books can be used as common incoming links, and the total number of incoming links can be greatly reduced.

In order to reduce the number of outgoing links in the STM switch, a plurality of outgoing links connected between the outgoing link editing unit and the output side external device are replaced with common outgoing links. The link editing unit may be configured to time-division multiplex the output data of the outgoing link assigned to the output-side external device to the output-side external device and send out the data via the common outgoing link. Thus, the number of outgoing links connecting the output side external device and the outgoing link editing unit can be one common outgoing link, and the total number of outgoing links can be greatly reduced.

In the above-mentioned STM switch, a circuit having a logical sum function is provided in the incoming link editing unit instead of the selector provided for each incoming link number, and each of the plurality of input-side external devices is provided with: It is possible to provide a gate element capable of gate control corresponding to each incoming link number and to control conduction / blocking of the passage of input data by the gate element. In addition, an AND circuit or an OR circuit can be used instead of the gate element of the input-side external device.

In the above-mentioned STM switch, a circuit having a logical sum function is provided in place of the selector provided for each output link number in a plurality of output-side external devices. It is possible to provide a gate element that can be gate-controlled in correspondence with the number and to control the conduction / cutoff of the passage of the output data by the gate element. Further, instead of the gate element of the outgoing link editing unit, an AND circuit or an OR circuit can be used.

Further, in order to realize the above (3), a plurality of input-side external devices are connected in cascade with M input links on the input link side of the STM switch, and then the M input input devices are connected. Each input-side external device is accommodated in the STM switch module by a link, and is configured such that input data of the own station is loaded only on the incoming link of the incoming link number assigned to the own station. In this configuration, each input-side external device puts its own input data only on the incoming link of the incoming link number assigned to it and puts it on the STM switch module for output. Therefore, the input-side external device does not have to be fixedly allocated, and each input-side external device can have a processing capacity corresponding to the number of assigned input links, so that the functions of the input-side external device can be used effectively. Become.

Alternatively, on the outgoing link side of the STM switch, a plurality of output side external devices are connected in cascade by M incoming links, respectively, and then accommodated in the STM switch module by N incoming links. The output-side external device is configured to extract output data necessary for the own station from the outgoing link of the outgoing link number assigned to the own station.
In this configuration, each output-side external device can take in only the output data of the outgoing link of the outgoing link number assigned to the own station. Therefore, the output-side external device does not have to be fixedly assigned, and each output-side external device can have a processing capability according to the number of assigned outgoing links,
The functions of the external device on the output side can be used effectively.

[0026]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Various embodiments of the present invention will be described below with reference to the drawings.

(1) Method of virtually allocating all links to each external device First, an embodiment of the method (1) of virtually allocating all links to each external device will be described.

FIG. 1 is a diagram showing the overall configuration of an STM switch according to this method (1). In the figure, reference numeral 1 denotes an STM switch module 1 having an incoming link and an outgoing link of 64 × 64. Reference numeral 2 denotes an incoming link editing unit, which is connected to the STM switch module 1 by 64 incoming links # 0 to # 63. Inf0 to inf7 are eight input-side external devices, which serve as an interface between the external line and the STM switch, and can output data for 64 links, respectively. Each of the input-side external devices inf0 to inf7 is connected to the incoming link editing unit 2 by 64 incoming links # 0 to # 63, respectively, so that data for a total of 64 × 8 links is provided. This is input to the incoming link editing unit 2. However, the incoming link editing unit 2 performs "narrowing down" of incoming link data from these external devices inf0 to inf7, and provides only 64 links of data to the STM switch module 1. ing.

Reference numeral 3 denotes an outgoing link editing unit, which is connected to the STM switch module 1 by 64 outgoing links # 0 to # 63. Inf'0 to inf'7 are eight output-side external devices, which serve as an interface between the STM switch and an external line, and each of which can input data for 64 links. Each of the external devices inf'0 to inf'7 on the output side is connected to the outgoing link editing unit 2 by 64 incoming links # 0 to # 63, so that a total of 64 × 8 links is provided. Minute data is output from the outgoing link editing unit 3. However,
The outgoing link editing unit 3 receives only data for 64 links from the STM switch module 1.

FIG. 2 shows an example of the configuration of an external device inf on the input side of the STM switch, and FIG. External device inf
There are eight in this embodiment, but only three are shown in FIG. In the illustrated example, one external device inf0 is 5
It has a function of processing data equivalent to 24.288 Mbps. That is, one unit can accommodate four STM1 lines (corresponding to 16 links). Also,
Each of the external devices inf1 and inf2 is 32.
It has a function of processing data equivalent to 768 Mbps, that is, one unit can accommodate 16 PCM 30 lines (corresponding to one link).

Here, the external device inf0 accommodates data for 16 links, and the data for 16 links is indicated by (A) to (P) in FIG. As described above, 64 links are virtually assigned to any of the external devices. Therefore, when the external device inf0 outputs data to the incoming link editing unit 2, the external device inf0 outputs the data shown in FIG.
As shown in the figure, the data (A) for the incoming link # 0 is
Data (b) is output to incoming link # 1, and data (P) is output to incoming link # 15. Further, the same data (A) is output again to the incoming link # 16, so that the data (A) to (P) are repeatedly output to the remaining incoming links # 15 to # 63. That is, data (A) to (P) are input links # 0 to # 7,
It is output to each set of incoming links # 16 to # 31, incoming links # 32 to # 47, and incoming links # 48 to # 63. In this way, since it is known that the external device inf0 accommodates 16 links, the external device inf0 autonomously outputs data for 16 links to the 64 incoming links # 0 to # 63 as described above. Is what you do.

On the other hand, the external device inf1 stores data for one link, and the data for one link is indicated by (Q) in FIG. Since 64 links are virtually allocated to the external device inf1, the incoming links # 0 to # 0 are assigned.
Data (Q) is output for all of # 63. Also in this case, since it is known that the external device inf1 contains data for one link, the external device inf1 autonomously outputs the data to the 64 incoming links # 0 to # 63.

The same applies to the external device inf2.
It stores data (R) for one link and outputs this data (R) to all of the incoming links # 0 to # 63.

As described above, the eight external devices inf
64 incoming links from # 0 to inf7 each # 0 #
63 is input to the incoming link editing unit 2.

The incoming link editing unit 2 shown in FIG.
The incoming links # 0 to # 63 are selected and input to the STM switch module 1.

The incoming link editing unit 2 includes 64 selectors SEL0 to SEL0 for each link number of the incoming link.
For example, the selector SEL0 corresponding to the incoming link number # 0 has eight external devices inf0 to inf.
7, the incoming link # 0 is input, and the selector SEL1 corresponding to the incoming link number # 1 is connected to the external device in.
Eight incoming links # 1 are input from f0 to inf7, and so on, and the input link of the corresponding input link number is input to each selector from each of the external devices inf0 to inf7. Then, for example, the selector SEL0 selects only one of the eight incoming links # 0 input thereto and outputs it to the STM switch module 1 as the incoming link # 0.
The EL 63 selects only one of the eight incoming links and outputs it to the STM switch module 1. The selection control of each of the selectors SEL0 to SEL63 is performed by a system control unit (not shown).

According to the above description, the external device inf0 has 16 links of data (A) to
(P) and accommodates the incoming link # 0 to the incoming link # 1.
5, incoming link # 16 to incoming link # 31, incoming link # 32
, The input link # 47 and the input link # 48 to the input link # 63. The external device inf1 stores data (Q) for one link and outputs it to all incoming links # 0 to # 63. The external device inf2 also stores data (R) for one link and outputs it to all incoming links # 0 to # 63.

These data are used as an incoming link to the STM switch module 1; incoming link # 0 to incoming link # 15: (A) to (P) incoming link # 16: (Q) incoming link # 17: The operation of the incoming link editing unit 2 in the case of (R) will be described below.

Data of the link number # 0 is input to the selector SEL0 of the incoming link editing unit 2 from each of the external devices inf0 to inf7. That is, data (A) is transmitted from the external device inf0, and data (Q) is transmitted from the external device inf1.
However, data (R) is input from the external device inf2.

The output of the selector SEL0 is given to the STM switch module 1 as an incoming link # 0, and the incoming link # 0 needs to be data (A). Therefore, for the selector SEL0, the external device i
Control is performed so as to select one from nf0. The other selectors SEL <b> 1 to SEL <b> 15 are controlled in the same way, and as a result, the incoming link is edited as described above.

As can be seen from the above description, in this embodiment, the input-side external device inf autonomously sends valid data to all incoming links # 0 to # 63 and the incoming link editing unit 2 The idea is to select truly valid data under the control of the control unit.

The configuration of the input external device inf and the input link editing unit 2 has been described above. The configuration of the output link editing unit 3 and the output external device inf 'will be described below.

FIG. 4 shows an example of the structure of the outgoing link editing unit 3.
5 and 6 show examples of the configuration of the external device inf 'on the output side. This applies the configuration on the input side described above to the output side. Although there are eight external devices inf ', only three are shown in FIG.

The outgoing link editing unit 3 shown in FIG. 4 transmits 64 outgoing links # 0 to # 63 from the STM switch module 1.
And outputs the outgoing links # 0 to # 63 to eight output-side external devices inf'0 to inf'7, respectively. In other words, the outgoing link editing unit 3 simply outputs the data of the outgoing links # 0 to # 63 from the STM switch module 1 to the eight external devices inf'0 to inf'7, as follows:
Send in 8 correspondence. In FIG. 4, outgoing links # 0 to # 17
Is shown, and data (A) to (R) are placed on outgoing links # 0 to # 17 and output, respectively, but the remaining outgoing links # 18 to (not shown) are shown.
Other data is also listed in # 63.

The external device inf 'shown in FIGS. 5 and 6 has the same number of selectors SEL as the number of links to be accommodated, and each selector SEL has 64 input outgoing links # 0 to #. 63, and one of the outgoing links is selected and output under the control of the system control unit.

That is, in the examples of FIGS. 5 and 6, the external device inf'0 accommodates data of 16 links, and the outgoing link # from the STM1 switch module 1
Data (A) to (P) of 0 to # 15 are allocated and 1
It has six selectors SEL0 to SEL15. Each of the external devices inf'1 and inf'2 accommodates data for one link.
1, the data (Q) of the outgoing link # 16, and the external device inf'2 also has the data (R) of the outgoing link # 17.
And each has one selector SEL.

The external device inf'0 is one of (A) to (P)
Although six types of data are taken in, as shown, 16 selectors (SEL0 to SEL15: where SEL1 to S
The EL 14 is not shown) is provided for this purpose. Data from all outgoing links # 0 to # 63 is input to each selector (only a part of them is shown in FIG. 5). In the selector SEL0, the outgoing link # 0 (corresponding to data (A)) is selected under the control of the system control unit, and thereafter, similarly, the outgoing link # 15 (corresponding to data (P)) is selected in the selector SEL15. You.

The external device inf'1 takes in data for one link. For this purpose, one selector SEL is prepared, in which the outgoing link # 16 (corresponding to data (Q)) is selected under the control of the system control unit. As described above, data from all outgoing links # 0 to # 63 is also input to the selector SEL, but FIG. 6 shows only a part of the data.

The external device inf'2 has the same configuration.
Here, outgoing link # 17 (corresponding to data (R)) is selected.

Note that the configuration of the external device inf'0 shown in FIG. 5 is applicable, but a modification shown in FIG. 7 is also possible. In the configuration of the external device inf 'shown in FIGS. 5 and 6, each of the 16 selectors (SEL0 to SEL15) selects 64 → 1 (selects one output from 64 inputs). In FIG. 7 as well, the number of selectors is 16 (partially omitted in the figure), but each selector SEL0-SEL
Reference numeral 15 denotes a selection of 4 → 1 (select one output from four inputs). 64 outgoing links # 0 to # 63 are input to the external device inf'0, but the outgoing link number. Connects # (16n + 0),
Similarly, for the selector SELl, # (16n + 1)
,... For selector SEL15
(16n + 15) are connected. Also in this configuration, the same effects as those in the configurations shown in FIGS. 5 and 6 can be obtained.

In implementing the present invention, various modifications are possible. For example, in the method on the input side of the embodiment described above, the external device inf autonomously sends valid data to all incoming links # 0 to # 63, and the incoming link editing unit 2 controls the external control unit 2 from the system control unit. The idea is to select truly valid data.

Therefore, on the contrary, the external device i on the input side
In the case of nf, an embodiment in which truly effective data is selected under the control of the system control unit to simplify the configuration of the incoming link editing unit 2 is also possible.

FIGS. 8 and 9 show an example. Here, FIG. 8 is a configuration example of the input-side external devices inf0, inf1, and inf2, and FIG. 9 is a configuration example of the input link editing unit 2.

The operation of the external device inf is basically the same as the case of the configuration shown in the above embodiment. For example, in the case of the external device inf0, the data for 16 links (A) to (P) is transferred to the incoming links # 0 to # 15 and # 16 to # 15.
# 31, incoming links # 32- # 47, incoming links # 48- #
Attempt to output as 63. However, in the actual output unit, as shown in FIG. 8, AND elements and0 to and63 are provided corresponding to the links # 0 to # 63 (however, FIG. 8 shows only a part thereof). The incoming link # 0 to the incoming link # 15 are links that should be truly valid, and the corresponding AND elements and0 to and1
5, each AND element and
“H” is given as one of the inputs 0 to 15. As a result, data (A) to (P) are output to incoming links # 0 to # 15. Incoming links # 16 to # 3
1, incoming links # 32 to # 47, incoming links # 48 to # 63
Is not a link that should be validated, and for the AND elements and16 to and63 corresponding to them (the AND element and32 and subsequent elements are omitted in FIG. 8), one of the AND elements and16 to and63 is sent from the system control unit. Is input as "L". Therefore, "L" is output to incoming links # 16 to # 63.

In the case of the external device inf1, 64 input links # 0 to # 63 are output from the output section, and the AND element and0 is applied to all of the input links # 0 to # 63.
And 63 are provided. However, FIG. 8 shows only a part thereof. The external device inf1 attempts to output the data (Q) as all the incoming links # 0 to # 63 of the output, but since only the incoming link # 16 is valid, only one of the inputs to the AND element and16 is set to "H". "
, And data (Q) is output only to incoming link # 16, and "L" is output to the other incoming links.

Similarly, in the external device inf2, data (R) is output only to the incoming link # 17, and "L" is output to the other incoming links.

The incoming link editing unit 2 shown in FIG. 9 is provided with 64 OR elements (OR elements or0 to or63, but only a part thereof is shown in FIG. 9). For example, the external device inf0 to the external device inf7 are connected to the OR element or0.
Are input to the respective incoming links # 0. As described above, although the data (A) is loaded on the incoming link # 0 from the external device inf0, the incoming links # 0 from the other external devices inf1 to inf7 are “L”. . Therefore, when these are ORed,
Only data (A) remains, which is given to STM switch module 1 as incoming link # 0.

In the embodiment described above, an AND element is prepared on the external device inf0 to inf7 side and an OR element is prepared on the input link editing unit 2 side on the input side.
It is obvious that the same effect can be obtained even if an OR element is prepared on the external device inf0 to inf7 side and an AND element is prepared on the incoming link editing unit 2 side. That is, the external devices inf0 to inf
A control signal is given from the system control unit to one input of the OR element prepared on the f7 side. "L" is given when data is to be made valid, and "H" is given when data is not to be made valid. Then, since the element is an OR element, H is output if the data is not to be made valid, as it is if the data is to be made valid. This is a form of input to the AND element on the incoming link editing unit 2 side.

FIGS. 10 and 11 show an embodiment in which the above-described embodiment on the input side (form using an AND element) is applied to the output side. FIG. 10 shows a configuration example of the outgoing link editing unit 3.
FIG. 11 shows a configuration example of the external device inf 'on the output side.

The outgoing link editing unit 3 has basically the same configuration as that shown in FIG. 4, but before output to the external device inf ', the outgoing link editing unit 3 applies an AND element to each of the outgoing links # 0 to # 63.
d0 and and63 are provided. A group of AND elements and0 to and63 is provided for each external device to be accommodated. That is, in this example, a group of 64 AND elements and0 to and63 is provided for each of eight sets, that is, for each of the external devices inf'0 to inf'7.

Here, out of a total of 64 outgoing links # 0 to # 63 to be output to the external device inf'0, outgoing links # 0 to # 15 are valid. Therefore, to the corresponding AND elements and0 to and15, “H” is given from the system control unit as the other input of each of the AND elements and0 to and15, and the data (A) to (P)
Is output. Since the outgoing links # 16 to # 63 are not valid, the corresponding AND elements and16 to and6
3, "L" is given as the other input of each of the AND elements and16 to and63, and the output is also "L".
Becomes FIG. 10 shows only a part of the AND element.

Similarly, since only the outgoing link # 16 is valid among the outputs to the external device inf'1, the AND element a
nd16, the other input becomes "H", data (Q) is output, and the remaining outgoing links # 0 to # 15, # 1
7 to # 63 are corresponding AND elements and0 to and1
The other input of 5, and 17 to and 63 is "L"
, And the output also becomes “L”. In the drawing, only a part of the AND element is shown. Similarly, the data (R) is output to the outgoing link # 17 in the output to the external device inf'2.

The external device inf'0 basically develops from that shown in FIG. Sixteen OR elements (OR elements or0 to or15, but OR elements or1 to or14 are omitted in FIG. 11) are provided corresponding to the 16 links. Each of the OR elements or0 to or15 is connected to four outgoing links in the same manner as in the configuration of FIG. As aforementioned,
Although data (A) to (P) are input as outgoing links # 0 to # 15, "L" is input as outgoing links # 16 to # 63. Therefore, as a result of the OR operation (logical sum), the data (A) to (P) become data for 16 links.

One or element is provided in each of the external devices inf ′ 1 and inf ′ 1. Each OR element or is connected with 64 outgoing links. Note that some outgoing links are omitted in the figure. Of these, the only valid one is the outgoing link # 16 (data (Q)
Outgoing link # 17 in the external device inf'2.
(Corresponding to data (R)), and the input as the other outgoing link is "L". Therefore, as a result of the OR operation (logical sum), data (Q) remains in the external device inf'1 and data (R) remains in the external device inf'2.

As in the description of FIGS. 8 and 9, also here, an OR element is prepared on the outgoing link editing section 3 and an AND element is prepared on the external device inf 'side to correspond to data to be made valid. The other input of the OR element is “L”
The same effect can also be obtained by giving "H" as the other input of the OR element corresponding to data that should not be regarded as valid from the system control unit.

As another embodiment of the present invention, an embodiment in which the AND element or the OR element of the above-described embodiment is replaced with a gate element is also possible. FIGS. 12 and 13 show configuration examples on the input side in this embodiment, and FIGS. 14 and 15 show configuration examples on the output side in this embodiment.

First, from the input side, FIG. 12 shows a configuration example of the external device inf on the input side, and FIG. 13 shows a configuration example of the incoming link editing unit 2. This is the output unit of the external device inf0 to inf7 (input links # 0 to # 63).
Are output), gate-controllable elements (gate gate in the figure) corresponding to all the incoming links # 0 to # 63, respectively.
0 to gate63). For truly valid data, a gate is opened to pass the data. For those that should not be valid, close the gate to prevent data from passing. In this case, the gate output is in a high impedance state (Hz in the figure). By doing so, it is possible to hit the outputs of each gate, so that the configuration of the incoming link editing unit 2 is very simple.

Next, the output side will be described. FIG. 14 shows an example of the configuration of the outgoing link editing unit 3, and FIG. 15 shows an example of the configuration of the external device inf 'on the output side. This is to provide a gate-controllable element (gates gate0 to gate63 in the figure) at the output unit of the outgoing link editing unit 3, and a group of these gates gate0 to gate63 is
Eight output-side external devices inf'0 to inf7 are provided correspondingly. Note that only some of these gates are shown in the figure. For valid data, a gate is opened to pass data, and for data that should not be valid, the gate is closed to prevent data from passing. In this way, the output of each gate is hit at the external device inf 'at the destination, thereby simplifying the configuration of the external device inf'.

The configuration of the input side and the output side has been described above.
There are a plurality of types of configurations on both the input side and the output side. And
Since the input side and the output side are independent with the STM switch module 1 interposed therebetween, any combination of configurations is possible. For example, in the above-described embodiments of FIGS. 2 to 6, the input side and the output side are configured to employ selectors. However, this is merely similar in configuration, and if a selector is adopted as the input side configuration, there is no necessity to adopt a selector as the output side.

When the above method is used, the external device inf0 (or inf'0) is equivalent to 16 links on the input side or the output side. The external device inf1 (or inf'1) is equivalent to one link. The external device inf2 (Or inf'2): A total of 18 links can be allocated to three external devices corresponding to one link.

In the conventional method (8 links are fixedly assigned to one external device) described in the section [Problems to be Solved by the Invention], the same accommodation as described above is required. (Or inf'0): Two external devices are implemented.-The external device inf1 (or inf'1): One external device is implemented (7 out of 8 links are useless). The external device inf2 is used. (Or inf'2): realized with one external device (7 out of 8 links are useless), and one external device and 14 links are wasted in the number of links.

(2) Method of grouping a certain number of external devices and allocating the number of links put together therewith This method (2) will be described below.

In the conventional example shown in FIG. 24, the STM switch module 1 and each of the external devices inf0 to inf7, in
There were only connections for every eight links between f'0 and inf'7. That is, the number of connections was 64 links on the input side and 64 links on the output side.

On the other hand, according to the method (1) shown in FIGS. 2 to 6, the connection between the STM switch module 1 and the incoming link editing unit 2 is 64 links, and It is 64 between editorial department 3
The number of links is the same as the number of connections in the conventional example. In addition, the external device i on the input side
The connection between nf0 to inf7 and the incoming link editing unit 2 is 64 ×
8 = 512, output-side external devices inf'0 to inf'7
And the outgoing link editing unit 3 also have 512 connections,
The number of connections for 024 links increases as compared with the conventional example. This method (2) makes the number of links allocated to external devices variable to some extent while slightly reducing the number of connections.

In the method (1), for example, the number of connections between the input-side external devices inf0 to inf7 and the input link editing unit 2 is calculated as follows.
The reason why the number of links is 64 for one external device inf is that one external device inf can accommodate data for 64 links. Realistically, an external device in
One piece of f does not accommodate as much as 64 links of data, but it is sufficient that 32 f or 16 links of data can be accommodated. Therefore, the eight external devices inf0 to inf7 on the input side and the eight external devices inf'0 to inf'7 on the output side are grouped into four units, for example, and 32 links are allocated to each group. Or, for example, grouping into two units and assigning 16 links to each group,
Consider introducing the above method (1) in each of those groups.

FIG. 16 shows a group in which four external devices are grouped and 32 links are allocated to each group.
7 groups external devices in groups of two and assigns 1 to each group.
6 links are assigned at a time. In any of the examples, the configurations of the input-side external device inf, the input-link editing unit 2, the output-link editing unit 3, and the output-side external device inf 'are the same as those shown in the method (1). 16, the input-side external device inf and the output-side external device i
The number of links allocated to one nf ′ is restricted to a maximum of 32, but the number is variable. Also, in FIG. 17, a maximum of 16 is similarly applied, but the number is variable. On the other hand, in the method (1), it was variable at a maximum of 64.

In the case of the method (1), the external devices inf0 to inf i
The connection between nf7 and the incoming link editing unit 2 and the outgoing link editing unit and the external devices inf'0 to inf'7 required a total of 1024 links, but in the system shown in FIG.
In the method shown in FIG. 17, 256 links are sufficient for two links.

On the other hand, the effect of making the link assignment variable is as follows. If the conditions are the same as those in the method (1), in the method (1), the external device inf0 (or inf ′) 0): Equivalent to 16 links ・ External device inf1 (or inf'1): assigned to 1 link ・ External device inf2 (or inf'2): Allocated 18 links to 3 external devices corresponding to 1 link It is possible. On the other hand, in the conventional example, in order to perform the same accommodation, the above-mentioned external device inf0 (or inf'0): two external devices are realized. The above-mentioned external device inf1 (or inf'1): external. One device is implemented (7 links out of 8 links are useless). The above-described external device inf2 (or inf'2): One external device is implemented (7 links out of 8 links are useless). As compared to 1), one external device and 14 links are wasted in the number of links.

In the method shown in FIG. 15, external device inf0 (or inf'9): equivalent to 16 links external device inf1 (or inf'1): equivalent to one link external device inf2 (or inf'2) : 1 link, and the same effect as that of the method (1) can be obtained.

In the case of the method shown in FIG. 17, external device inf0 (or inf'0): equivalent to 16 links external device inf1 (or inf'1): unusable external device inf2 (or inf'2) 1 corresponds to 1 link ・ External device inf3 (or inf'3): 1 link, which is the same as the conventional example.

As can be seen from the above comparison results, to reduce the connection between the external devices inf, inf 'and the incoming link editing unit 2 or outgoing link editing unit 3, it is necessary to reduce the grouping unit. Although effective, the effect of making the link assignment variable is more apparent as the unit of grouping is larger. This is considered to be a method (1) of ultimately grouping one group for 64 links. The method of forming two groups by 32 links (the method of FIG. 16) is effective in that the number of connections can be reduced while maintaining the effect of making the link assignment variable.

From the viewpoint of reducing the number of connections,
External device inf, incoming link editing unit 2 and outgoing link editing unit 3
A time-division multiplexing method between the external device inf 'and the external device inf' is possible. FIG. 18 shows the embodiment.

As shown in the prior art, data input / output to / from the external devices inf and inf 'are originally obtained by time-division multiplexing 512 time slots in one frame. In FIG. 18, this multiplicity is further increased by 64 times (the transmission speed is also 64 times), and 64 incoming links # 0 to # 63 in one frame (512 time slots are multiplexed in each incoming link # 0 to # 63). Is multiplexed). Although the frame format is not shown, the outgoing links # 0 to # 63 are also multiplexed similarly. According to this method, the external device i
The connection between nf, the incoming link editing unit 2 / outgoing link editing unit 3 and the external device inf 'is only for a total of 16 multiplex links, which can be greatly reduced as compared with the method (1).

In the case of this system, the external device inf on the input side
The detailed configuration of the incoming link editing unit 2 is shown in FIGS. Here, FIG. 19 shows the external devices inf0 and inf on the input side.
f1 and inf2 (external devices inf2 to inf7 are not shown), and FIG. 20 shows the configuration of the incoming link editing unit 2.

In the case of the method (1), the input-side external device in
f0 to inf2 and the configuration of the incoming link editing unit 2, FIG.
It is similar to FIG. The difference is the external device inf0-inf
The multiplexer MUX is disposed at the output of the input link editing unit 2 and the multiplexer MUX is multiplexed for 64 links.
MUX is arranged and this demultiplexer DEMUX
The point is that four links are separated. Other parts are the same as those in FIGS. 2 and 3, and the operations of those parts are the same as those in FIGS. 2 and 3, and therefore detailed description of the operations will be omitted.

The outlink editing unit 3 and the external device inf 'on the output side in this system are shown in FIGS. 4, 5, and 6, which are the configurations in the system (1). The multiplexer MUX is connected to the output of the external device inf'0
This is an embodiment in which a demultiplexer DEMUX is arranged at the input section of .about.inf'7. Naturally, this method can be applied to the configuration of the output-side external device in FIG.

Naturally, on the input side, a multiplexer MUX is added to the configuration shown in FIGS. 8 and 9 using an AND element and an OR element.
A configuration in which a / demultiplexer DEMUX is added is also possible. Similarly, an extension of the configuration in FIGS. 10 and 11 using an AND element and an OR element on the output side is also conceivable.

FIGS. 12 to 15 using a gate element.
In the case of the configuration, since Hz is related,
Since the separating operation cannot be performed, a configuration that is an extension of FIGS. 12 to 15 cannot be performed.

As described above, according to this configuration, the same effect as that of the method (1) can be obtained, and the number of connections can be reduced.

(3) System for Connecting the STM Switch Module 1 to Each External Device in a Bus Mode Hereinafter, this system (3) will be described.

The method (1) is for each external device inf0 on the input side.
~ Inf7 and the incoming link editing unit 2 are connected in a star format,
Similarly, the outgoing link editing unit 3 and each external device in the output side in
f'0 to inf'7 are also connected in a star format. That is, each of the external devices inf0 to inf7, in
In this system, an incoming link editing unit 2 and an outgoing link editing unit 3 are provided between f'0 to inf'7 and the STM switch module 1.

In this section, the external device inf0 to inf7, or in
f'0 to inf7 are connected in the form of a bus, and finally ST
A method for connecting to the M switch module 1 will be described.

FIG. 21 shows an embodiment of this bus system.
Also in this method (3), each of the external devices inf0 to inf7, i
There are virtually 64 links each for nf'0 to inf'7. On the input side, the external device in
f0 is located at the "most upstream", and hereinafter, the external device inf1,
via inf2... inf7 and finally STM
Connected to switch module 1. On the output side, ST
First, the M switch module 1 is connected to the external device inf'7, and thereafter, the external devices inf'6, inf'5,.
-Via inf'1, it is finally connected to the external device inf'0 located at the "most downstream". The “connection order” of these external devices is not particularly meaningful, and even if the external device inf7 is located at the “most downstream” on the input side and the external device inf′7 is located at the “downstream” on the output side. No problem.

FIG. 22 shows a detailed configuration example of the external device inf on the input side. The external device inf0 is one of (A) to (P)
It stores data for 6 links, and (A)-(P)
Is assumed to be output as incoming links # 0 to # 15, and it is assumed that the external device inf1 accommodates data for one link of (Q) and outputs it as the incoming link # 16.

In each external device inf, 64 selectors are prepared corresponding to all the incoming links # 0 to # 63 virtually allocated. In FIG. 22, the illustration of the selector is partially omitted. Whether the selector SEL0 outputs its own data as the incoming link # 0,
This selects whether to output the data of the incoming link # 0 from the external device inf on the upstream side.
x is for selecting data of the incoming link #x.

In the external device inf0, one of (A) to (P)
Although there are data for six links, as shown in the figure, data (A) includes selectors SEL0, SEL16, SEL32,
Input to the four selectors of SEL48. FIG. 2
2, the illustration of the selector is partially omitted. Similarly, data (P) is stored in selectors SEL15, SEL31, and SEL4.
7, input to SEL63. The selection control of each selector SEL is performed under the control of a system control unit (not shown).

In the external device inf0, data (A) to
Since (P) is output as incoming links # 0 to # 15, an instruction of "selecting own data" is given to selectors SEL0 to SEL15. As a result, the data (A) to (P) in the external device inf0 enter the incoming link # 0.
# 15 are output to the external device inf1 at the next stage.
The other selectors SEL16 to SEL63 are given an instruction of “selection of an incoming link”, and the data from the external device inf at the preceding stage (although “external stage” does not exist in the external device inf0) “passes through”. It becomes a form to go.

Although the external device inf1 has data for one link (Q), as shown in FIG.
It is input to 0-SEL63. In the drawings, some illustrations are omitted. Then, an instruction of “own data selection” is given only to the selector SEL16, whereby the data (Q) is output to the next-stage external device inf2 as the incoming link # 16. Other selectors SEL0 to SEL15, SEL17 to SEL63
Has been given an instruction of “selection of an incoming link”, and the data from the external device
I will do it. Therefore, data (A) to (P) are output as incoming links # 0 to # 15.

In the above description, data is selected by the selector. However, as described in the method (1), an AND / OR element or a gate is used instead of the selector. can do.

FIG. 23 shows a configuration example of the external device inf 'on the output side. Similarly to the input side, the external device inf'0 is 16
Data for link (outgoing links # 0 to # 15) (A) to
(P), and the external device inf'1 accommodates data (Q) for one link (outlink # 16). In this embodiment, each output-side external device inf'0
To inf'7 are provided with the same number of selectors as the number of data accommodated in the own station.

Each of the external devices inf'0 to inf'7 is
This is a mode in which data for 64 outgoing links is received from the external device inf 'on the upstream side and is passed to the external device inf' on the downstream side as it is. In FIG. 23, some outgoing links are not shown. Then, in the external device inf'1, in order to extract data for one link, a selector (S in the figure)
EL). This selector SEL has a total of 64
Data of outgoing links # 0 to # 63 are input. FIG.
Here, some illustrations are omitted. The selector SEL is instructed by the system control unit to select the outgoing link # 16, and the data (Q) is extracted from the outgoing link # 16.

In the external device inf'0, there are 16 selectors (SEL in the figure) for extracting data for 16 links.
0 to SEL15: some are omitted).
Outgoing links # 0, # 16, # 32,
# 48 is provided to the selector SELl as outgoing links # 1 and # 1.
The outgoing links # 15, # 31, # 47, and # 63 are input to the selector SEL15. In FIG. 23, illustration is partially omitted. Then, the system controller selects the outgoing link # 0 for the selector SEL0, the outgoing link # 1 for the selector SEL1,... The outgoing link # 15 for the selector SEL15. Are designated, and data (A) to (P) are extracted here.

Although the embodiment in which data is selected by the selector has been described above, it is also possible to use an AND / OR element or a gate instead of the selector, as in the method (1). The effect of this method is
(1) The effect is completely the same as that of the method.

[0104]

As described above, according to the present invention, it is sufficient that the external device has only the processing capacity corresponding to the number of links allocated to the external device. In other words, the number of links allocated to each external device can be made variable in accordance with the specifications of the interface with the external device, so that the function of the external device in the fixed allocation method can be avoided.

[Brief description of the drawings]

FIG. 1 is a diagram showing an overall configuration of an embodiment of an STM switch according to a method (1) according to the present invention.

FIG. 2 is a diagram illustrating a configuration example (selector system) of an input-side external device in the embodiment of FIG. 1;

FIG. 3 is a diagram illustrating a configuration example (selector system) of an incoming link editing unit in the embodiment of FIG. 1;

FIG. 4 is a diagram showing a configuration example (selector system) of an outgoing link editing unit in the embodiment of FIG. 1;

FIG. 5 is a diagram (1/2) illustrating a configuration example (selector system) of an output-side external device in the embodiment of FIG. 1;

FIG. 6 is a diagram (2/2) showing a configuration example (selector system) of an output-side external device in the embodiment of FIG. 1;

FIG. 7 is a diagram illustrating another configuration example (selector system) of the external device on the output side in the embodiment of FIG. 1;

8 is a diagram showing another configuration example (an AND / OR element system) of the input-side external device in the embodiment of FIG. 1;

9 is a diagram illustrating another configuration example (an AND / OR element system) of the incoming link editing unit in the embodiment of FIG. 1;

FIG. 10 is a diagram showing another configuration example (an AND / OR element system) of the outgoing link editing unit in the embodiment of FIG. 1;

11 is a diagram illustrating another configuration example (an AND / OR element type) of the external device on the output side in the embodiment of FIG. 1;

FIG. 12 is a diagram showing another configuration example (gate element system) of the input-side external device in the embodiment of FIG. 1;

FIG. 13 is a diagram showing another configuration example (gate element system) of the incoming link editing unit in the embodiment of FIG. 1;

FIG. 14 is a diagram showing another configuration example (gate element system) of the outgoing link editing unit in the embodiment of FIG. 1;

FIG. 15 is a diagram showing another configuration example (gate element system) of the external device on the output side in the embodiment of FIG. 1;

FIG. 16 is a diagram showing an overall configuration of an embodiment of an STM switch according to the system (2) according to the present invention (grouping of four external devices).

FIG. 17 is a diagram showing an overall configuration of another embodiment (two external devices are grouped) of the STM switch according to the method (2) according to the present invention.

FIG. 18 is a diagram showing an overall configuration of an embodiment (time division multiplex link system) for reducing the number of wirings in an STM switch according to the present invention.

FIG. 19 is a diagram illustrating a configuration example of an external device in the embodiment of FIG. 18;

20 is a diagram illustrating a configuration example of an incoming link editing unit in the embodiment of FIG. 18;

FIG. 21 is a diagram showing an overall configuration of another embodiment (bus system) of the STM switch according to the system (3) according to the present invention.

22 is a diagram illustrating a configuration example of an external device on the input side in the embodiment in FIG. 21;

23 is a diagram illustrating a configuration example of an external device on the output side in the embodiment in FIG. 21;

FIG. 24 is a diagram showing an overall configuration of a conventional STM switch.

[Explanation of symbols]

 Reference Signs List 1 STM switch module 2 Incoming link editing unit 3 Outgoing link editing unit inf0 to inf7 External device on input side inf'0 to inf'7 External device on output side and0 to and63 AND element or0 to or63 OR element gate Gate (A) to (R) Data

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Masaki Sakai 4-1-1, Kamiodanaka, Nakahara-ku, Kawasaki-shi, Kanagawa Prefecture Inside Fujitsu Limited (72) Inventor Sachiko Inoue 4-1-1, Kamiodanaka, Nakahara-ku, Kawasaki-shi, Kanagawa No. 1 Fujitsu Limited F term (reference) 5K028 LL02 RR01 TT01 5K069 BA02 CB08 DA04 DB11 DB52 EA07 FA26

Claims (14)

[Claims] An incoming link and an outgoing link are M × N (however,
M and N are integers of 2 or more), a plurality of input-side external devices for interfacing the STM switch module with the outside on the input side, and interfacing the STM switch module with the outside on the output side. STM switch comprising a plurality of output-side external devices for arranging an input link editing unit between the STM switch module and the input-side external device, the STM switch module and the input link editing device The sections are connected by M incoming links,
The incoming link editing unit and the plurality of input-side external devices are connected by M incoming links, respectively, and the incoming link editing unit includes M selectors corresponding to each link number of the incoming link. An STM switch, wherein each of the selectors is configured to input an incoming link of a corresponding link number from the plurality of input-side external devices. 2. An incoming link and an outgoing link are M × N (however,
M and N are integers of 2 or more), a plurality of input-side external devices for interfacing the STM switch module with the outside on the input side, and interfacing the STM switch module with the outside on the output side. STM switch comprising a plurality of output-side external devices for providing an outgoing link editing unit between the STM switch module and the output-side external device, the STM switch module and the outgoing link editing Parts are connected by N outgoing links,
The outgoing link editing unit and the plurality of output side external devices are respectively connected by N outgoing links, and each of the plurality of output side external devices is associated with each link number of the outgoing link. An STM switch comprising N selectors, each of which receives a required one of N outgoing links from the outgoing link editing unit. 3. An incoming link and an outgoing link are M × N (however,
M and N are integers of 2 or more), a plurality of input-side external devices for interfacing the STM switch module with the outside on the input side, and interfacing the STM switch module with the outside on the output side. STM switch comprising a plurality of output-side external devices for arranging an input link editing unit between the STM switch module and the input-side external device, the STM switch module and the input link editing device The sections are connected by M incoming links,
The incoming link editing unit and the plurality of input-side external devices are connected by M incoming links, respectively, and the incoming link editing unit includes M selectors corresponding to each link number of the incoming link. A plurality of input links corresponding to the input link numbers from the plurality of input-side external devices are input to the respective selectors, and an outgoing link is edited between the STM switch module and the output-side external device. And an N outgoing link is connected between the STM switch module and the outgoing link editing unit.
The outgoing link editing unit and the plurality of output side external devices are respectively connected by N outgoing links, and each of the plurality of output side external devices is associated with each link number of the outgoing link. An STM switch comprising N selectors, each of which receives a required one of N outgoing links from the outgoing link editing unit. 4. An incoming link editing unit is provided for each group by dividing the M incoming links of the STM switch module into a plurality of groups, and each incoming link editing unit is assigned an incoming link assigned to each incoming link editing unit. 4. The STM switch according to claim 1, wherein an incoming link is connected to an input external device accommodated by the number of links. 5. The N outgoing links of said STM switch module are divided into a plurality of groups, and an outgoing link editing section is provided for each group, and each outgoing link editing section is assigned to each outgoing link editing section. 4. The STM switch according to claim 2, wherein an outgoing link is connected to the output side external device accommodated by the number of links. 6. A plurality of incoming links connected between the incoming link editing unit and the input external device are replaced with a common incoming link, and each input external device is assigned an incoming link assigned to its own station. 5. The STM switch according to claim 1, wherein said input data is time-division multiplexed and transmitted to said incoming link editing unit via said common incoming link. 7. A plurality of outgoing links connected between the outgoing link editing unit and the output side external device are replaced with a common outgoing link, and the outgoing link editing unit outputs the output side to the output side external device. 6. The STM switch according to claim 2, wherein output data of an outgoing link assigned to an external device is time-division multiplexed and transmitted through said common outgoing link. 8. A circuit having a logical sum function is provided in the incoming link editing unit instead of the selector provided for each incoming link number,
4. The device according to claim 1, wherein each of said plurality of input-side external devices is provided with a gate element that can be gate-controlled in correspondence with each incoming link number, and controls conduction / interruption of the passage of input data by said gate element. 7. The STM switch according to 4, 4 or 6. 9. A circuit having a logical sum function is provided in said plurality of output side external devices in place of a selector provided for each outgoing link number, and a gate control is provided in said outgoing link editing section for each incoming link number. 8. The STM switch according to claim 2, wherein a possible gate element is provided to control conduction / cutoff of the passage of output data by said gate element. 10. The STM switch according to claim 8, wherein said STM switch is constituted by an AND circuit or an OR circuit in place of said gate element of said external device on the input side. 11. The STM switch according to claim 9, wherein said STM switch comprises an AND circuit or an OR circuit in place of said gate element of said outgoing link editing unit. 12. An incoming link and an outgoing link are M × N (however,
M and N are integers of 2 or more), a plurality of input-side external devices for interfacing the STM switch module with the outside on the input side, and interfacing the STM switch module with the outside on the output side. Switch comprising a plurality of output-side external devices for connecting the plurality of input-side external devices in a cascade with M input links, respectively, and then connecting the STM switch with the M input links.
An STM switch housed in a switch module, wherein each input-side external device is configured so that input data of its own station is loaded only on an incoming link of an incoming link number assigned to its own station. 13. An incoming link and an outgoing link are M × N (however,
M and N are integers of 2 or more), a plurality of input-side external devices for interfacing the STM switch module with the outside on the input side, and interfacing the STM switch module with the outside on the output side. Switch comprising a plurality of output-side external devices for cascading each of the plurality of output-side external devices through M incoming links and then connecting the STM switch through N incoming links.
An STM switch housed in a switch module and configured so that each output-side external device takes out output data necessary for the own station from an outgoing link of an outgoing link number assigned to the own station. 14. An incoming link and an outgoing link are M × N (however,
M and N are integers of 2 or more), a plurality of input-side external devices for interfacing the STM switch module with the outside on the input side, and interfacing the STM switch module with the outside on the output side. Switch comprising a plurality of output-side external devices for connecting the plurality of input-side external devices in a cascade with M input links and then connecting the STM switch with M input links.
Each input-side external device is accommodated in a switch module, and the input data of its own station is placed only on the incoming link of the incoming link number assigned to its own station. Cascade with N incoming links and N
An STM switch housed in a switch module, wherein each output-side external device is configured to extract output data necessary for the own station from an outgoing link of an outgoing link number assigned to the own station.