JP3479427B2 - Method for reducing path connection resistance in MDF 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 path connection resistance reducing method for reducing DC resistance in an MDF (main distribution board or line distribution device: Main Distributed Frame) system.

The DC resistance of an MDF system is mainly given by the sum of the conductor resistances of the matrix board (MB) and the back-wired board (BWB) in the system. Generally, in MDF, physical specifications such as the size of the matrix board (MB) and wiring specifications are optimized according to the system scale. In addition, in order to accommodate a larger number of subscriber lines in the MDF, the area is increased and the conductor resistance is increased in proportion to it, and the standard for satisfying a predetermined communication quality must be satisfied. May not be possible.

[0003]

2. Description of the Related Art FIG. 7 is a functional explanatory diagram of an MDF (main distribution board or line distribution device) system. The MDF is a device for connecting each subscriber line, to which a plurality of subscriber terminals (telephones, etc.) are connected, to a designated subscriber circuit of the exchange, and in many cases, it is provided in the exchange. However, it may be housed in an outdoor subscriber termination device.

When a large number of subscriber lines are collected in a station building as a bundle of cables underground or on the ground, each line is connected to an arrester via a connector. The arrester has a function to protect the exchange from overcurrent (lightning strike, short circuit, etc.). Each subscriber line is connected to the MDF via an arrester. The structure of the MDF is shown in FIG. 8 described later. The other end is connected to each subscriber circuit of the exchange through a connector via the MDF path, and a part is connected to a transmission device accommodating a trunk line.

The MDF connects a new line to a subscriber circuit of the exchange when a new subscriber joins, or changes the connection when the subscriber moves or the telephone number is changed. Or change the connection of the path to the subscriber circuit of the exchange so that the subscriber receives a new service (for example, from the subscriber circuit for normal telephone service to the subscriber circuit for ISDN service). It has a function. M
The DF path connection may be changed while the exchange is operating. In addition, in order to efficiently change the path connection, generally, the number of terminals on the subscriber side (for example, 360
The number of terminals (0 terminals) is greater than the number of terminals on the exchange side (for example, 2100 terminals).

In the conventional MDF, a terminal board for accommodating a subscriber line is provided, and a pair of subscriber lines are formed between the subscriber line and the terminal board and between the terminal board and the subscriber circuit of the exchange. The connection between the subscriber and the exchange was made by connecting the two cables (A line and B line) with a cable, and manually connecting the two terminal boards with a jumper line. Therefore, a professional engineer is required for this work, and a lot of time is required for the work because it involves delicate manual work. Therefore, in recent years, an automatic MDF in which a robot performs a jumper work has been introduced.

FIG. 8 shows a configuration example of a conventional MDF. A.
As shown in FIG. 3, the MDF is composed of three stages of a primary switch (SW) unit, a secondary switch (SW) unit, and a tertiary switch (SW) unit. It is configured by using a plurality of matrix boards (referred to as MB) as shown in FIG. A connection path is formed through each switch for connecting between the subscriber line and the exchange (subscriber circuit). MB is a multilayer printed board, and is printed and wired such that a large number of lines in the X (row) direction and a large number of lines in the Y (column) direction intersect at right angles in different layers. A. In the example, the lines in the row direction are wired on the front surface, and the lines in the column direction are wired on the back surface shown by the dotted line. The row and column wirings are connected to the terminals of a connector provided on one side of the matrix board in correspondence with the wirings in each direction by printed wiring.

A difference hole (hole) is provided at each intersection of a plurality of wirings in the row direction and the column direction of the MB, and a connecting pin (not shown) is inserted from the top into the difference hole to obtain a desired shape. The lines in the row direction and the lines in the column direction can be electrically connected (paths are connected). In recent years, the insertion of connecting pins has been automatically performed by robots.
Each subscriber line consists of a pair of A and B lines.
By inserting a connecting pin at each difference point, the difference points of the pair of lines A and B are connected. The above A. Shown in 3
In order to connect the subscriber line and the subscriber circuit of the exchange with the switch section of one stage, one connecting pin is inserted at the difference point of each matrix board constituting each of the primary, secondary and tertiary switch sections. There is a need. After the connection is made by inserting the connection pin, the connection is maintained semi-fixed unless the subscriber moves or the subscriber circuit is changed.

The number of wirings in the row direction and the number of wirings in the column direction of each matrix board are limited by the physical size of the matrix board, the density of the wiring pattern, etc., and a fixed number is accommodated (for example, , 2 in the row / column direction
00 pairs x 120 pairs).

FIG. 9 is a diagram for explaining the relationship between the switch parts.
9A. Shows the connection relationship between the matrix boards of each switch section. Each of the primary to tertiary switch parts is composed of a large number of matrix boards (MB), and the third switch of the tertiary switch is connected from an arbitrary input terminal of the primary switch part accommodating the subscriber line. It has a configuration in which an arbitrary terminal and a path are connected. That is, in FIG. As shown in, each matrix board of the primary switch is provided with printed wiring so that it can be connected to all the matrix boards of the secondary switch section, and this wiring is called a link.
Similarly, each matrix board of all secondary switches is provided with a link for connecting to all matrix boards of the tertiary switch section.

FIG. 9B. Shows a physical structure for housing the matrix board. The matrix board is a plug-in type Back Wired Board (BWB)
Is abbreviated as ") and is connected to each terminal of the back wired board (BWB) by a connector. On the back wired board (BWB), corresponding to each back wired board, the A. A wiring pattern forming a link as shown in is printed. That is, 1
Links are provided so that each matrix board of each of the secondary to tertiary switches can be connected to each other.

The MDF system having such a structure is adopted in the public network telephone station, but as one of the electrical standards, the loop resistance of the A / B line (A from the primary switch part to the tertiary switch part) is used. The line resistance when the line and the B line are folded back at the end) is set to 10Ω or less as a target, and it is specified to be 20Ω or less in operation.

On the other hand, as a new matrix board (MB), an aggregate matrix board (aggregate MB) having a plurality of MBs is adopted, and FIG. 10 shows the configuration of an aggregate MB having two MBs.

In FIG. 10, 10 is a set MB, 11,
12 is a matrix board (M
B) of FIG. In this example, there are 124 difference points in the row direction and 100 points in the column direction.
Difference points are provided. Among these MB11, 12, MB11 provided at a position far from the connector (15, 16) described later (the DC resistance value of the path to the connector is high) is set to an even number (or an old number), MB12 close to the connectors 15 and 16 (the DC resistance value of the path to the connector is low) is set to an odd number (or a young number).

Numerals 13 and 14 are connection pin supply portions for supplying connection pins when the connection pins are automatically inserted into the difference points. At the initial stage (when the connection pins are not used), MBs 11 and 12 are provided.
Each of them has a capacity capable of supplying 120 pins.

Numeral 15 is a connector of 440 pins (two pins of A line and B line for one line, 220 lines), which is connected to each line of the matrix boards 11 and 12 in the Y-axis (vertical) direction. Wiring is formed on the surface of the board, and each pin is connected to each wire on the back-wired board by inserting the assembly MB10 into a predetermined position of the back-wired board (see FIG. 9B).
When this set MB is used as a primary switch unit, a subscriber line from the outside is connected to this connector 15, and when it is used for a tertiary switch unit, it is connected to a subscriber circuit of an external exchange so that it is an IO connector. Called.

Reference numeral 16 is a connector of 496 pins (for 248 lines), which is a row (horizontal) of the matrix boards 11 and 12.
The printed wiring to be connected to each line in the direction is formed on the back surface (or the intermediate layer) of the board, and the connector 16 inserts the assembly MB10 at the connection position of the back wired board so that each pin connects to each wire on the back wired board. To be done. When this set MB10 is used as a primary to tertiary switch unit, this connector 16 is called a link connector because it is connected to a link.

This set MB10 is the A. Shown in 1
A matrix board of any one of the secondary to tertiary switches is constructed, and the number of sets MB designed corresponding to the scale of the exchange (the number of subscribers accommodated) is the primary to tertiary switch parts. Is provided as.

When the switch section is constructed by using a plurality of sets MB, the matrix board 11 provided at a position far from the connectors 15 and 16 is set to an even number (or called an old number), and the connectors 15 and 16 are set. The adjacent matrix boards 12 are set to have an odd number (or called a young number). For example, when a certain switch unit is composed of a plurality of set MBs, the number 0 and the number 1 are set in the two matrix boards of the head set MB, and the number 2 and the number 3 are set in the two matrix boards of the next set MB. Is set and the numbers are sequentially set in the same manner. In the case of the even-numbered (old-numbered) matrix board 11 described above, the connector board 15 is connected to the matrix board 1
Since the path extending from 1 to the connector 16 has a long distance, the resistance value is high, and the path through the odd (young) matrix board 12 has a short distance and the resistance value is low.

In the MDF system using the two matrix boards 11 and 12 of the set MB10 shown in FIG.
Horizontal size is 538.9 mm, vertical size is 2
It is 32 mm. This size is
The area ratio is 6 times, and the conductor resistance has increased several times.
The maximum resistance value per MB (path passing through even-numbered matrix boards) is 4.6Ω (loop), and the resistance value passing through odd-numbered matrix boards is lower than that.

On the other hand, the maximum value of the resistance value in the MDF is defined by the public telecommunications carrier in order to maintain the communication quality, and the sum of the resistance values in the primary to tertiary switch parts is The total resistance value, which is the sum of the resistance values of the link between the primary switch part and the secondary switch part (formed by a back-wired board) and the link between the secondary switch part and the tertiary switch part, may be 20Ω or less. Is required.

FIG. 11 shows an M when a collective MB having two MBs is connected to a back wired board (BWB).
It is explanatory drawing of the connection path of DF. In the figure, 10a to 10c
Is a set M that constitutes a primary switch unit to a tertiary switch unit
It is one of B, and is a primary MB, a secondary MB, and a tertiary M, respectively.
B represents, and 17 represents BWB. 1st MB to 3rd M
B is an even number (old number) MB11a, 11b,
11c and odd-numbered (younger) MBs 12a, 12b, 12c
And IO connectors 15a, 15b,
15c and link connectors 16a, 16b, 16c are provided, and a link is formed by connecting to the BWB 17 and is connected to the line side (subscriber line) and the inside of the office (subscriber circuit of the exchange).

In the case of FIG. 11, the subscriber line is connected from the BWB 17 to the IO connector 15a of the primary MB 10a, and is connected to the link connector 16a through the difference point (not shown) of one of the even-numbered MB and the odd-numbered MB. It is connected to the link of BWB17. This link is then connected to the IO connector 15b through the difference point between the link connector 16b of the secondary MB 10b and the even number (old number) MB 11b or the odd number (young number) 12b, and is then connected to the link of the BWB 17. . The link is further connected from the BWB 17 to the link connector 16c of the tertiary MB 10c, and the matrix board 1
It is connected to the IO connector 15c via the difference point of either 1c or 12c and is connected to the inside of the station. In this way, the MDF path is connected.

[0024]

The above-mentioned MD shown in FIG.
In F, the matrix boards that make up the primary, secondary, and tertiary switch sections are arbitrarily selected and the paths are connected, but the two matrix boards mounted on each aggregate matrix board are all connected in each switch section. If it is an even number (old number), the type resistance of the matrix board is 13.8 Ω (4.6
Since the worst conductor resistance of BWB (when the wiring pattern of the link is longest) is 8Ω in Ω / MB × 3 old MB), there is a problem that the standard of 20Ω cannot be satisfied in total.

FIG. 12 shows a distribution of cumulative resistance values in the case where all the primary to tertiary switch sections include path connections passing through even-numbered (old number) MBs. ~ The measured value of the distribution of the values obtained by adding the respective resistance values of the tertiary switch unit, the vertical axis is the number of paths, and the horizontal axis is the cumulative resistance value of each of the three switch units (excluding the resistance value of the back wired board). ) Represents.

The present invention uses a collective matrix board equipped with a plurality of matrix boards to connect a subscriber line to a circuit of an exchange through a path through a three-stage switch section.
It is an object of the present invention to provide a path resistance reducing method for making the cumulative resistance value of a bus equal to or less than the value defined in the standard in an F system.

[0027]

In order to achieve the above object, the present invention provides a matrix board in each of primary, secondary, and tertiary switch sections which are composed of an aggregate matrix board including a plurality of matrix boards. When a path passing through one of (MB) is selected, a path selection algorithm is provided so that all three switch units do not select an even number (old number).

FIG. 1 illustrates the principle of the present invention. In the figure,
Reference numeral 1 is a processing unit for selecting a matrix board (referred to as a secondary MB) of a secondary switch unit of an MDF including three-stage switch units of primary to tertiary using a set matrix board, and 2 is a memory. In the processing unit 1, 1a is a subscriber accommodation 1
Next MB (matrix board) type identifying means, 1b is a subscriber circuit accommodating third MB identifying means, and 1c is a priority MB for determining which type of even-numbered or odd-numbered secondary MB has priority.
Next MB type selection means, 1d is the secondary MB of the selected type
Priority type selection secondary MB extraction means for searching for a path by, 1e is a secondary M of another type when there is no available path.
It is another type secondary MB extraction means for searching B.

Further, in the memory 2, 2a is a type (an even number or an odd number) of an aggregate matrix board of a primary switch unit and a tertiary switch unit that accommodates the subscriber line and the subscriber circuit of the exchange. 2b is a discrimination table, 2c is a link between each MB of the primary switch unit and each MB of the secondary switch unit, and each MB of the secondary switch unit and each of the tertiary switch unit. It is a link table that stores the state (empty or in use) of links between MBs.

When one of the secondary MBs is selected, the subscriber line to which the path is connected and the accommodating position of the subscriber circuit on the exchange side to which the subscriber is connected (MB number and connection therein) Position) is given. First, the subscriber accommodation first M
The B type identification means 1a refers to the accommodation table 2a to identify the type of the primary MB in which the subscriber line is accommodated (even number (old number) or odd number (young number)), and then the subscriber Similarly, the accommodation table 2 is used in the circuit accommodation third MB identifying means 1b.
The type of the primary MB is identified by referring to a. Subsequently, the priority secondary MB type selection means 1c refers to the discrimination table 2b based on the types of the identified primary MB and tertiary MB,
The secondary MB type to be prioritized is determined. Discrimination table 2b
In the field, information indicating that the type of the secondary MB to be prioritized or any type can be set is set in correspondence with the combination of the types of the primary MB and the tertiary MB.

As a result, when both the primary MB and the tertiary MB are even numbers (old numbers), the secondary MB is given an odd number (young number), and both the primary MB and the tertiary MB are odd numbers. It can be seen that in the case of (younger number), the even number (older number) is prioritized in the secondary MB, and in any other case, any number is acceptable. The priority secondary MB type selection means 1c defines the priority type (1
When the priority type (when the primary MB and the tertiary MB are different types) is selected as the next MB and the tertiary MB are the same type) or when any one of the types is selected, the priority type secondary MB extraction means is next selected. The search for the secondary MB according to the priority type is started for 1d.
This search is performed by selecting from among a large number of secondary MBs corresponding to the priority type, a link with the primary MB accommodating the subscriber line for path connection, and a tertiary MB accommodating the subscriber circuit. One secondary MB with a free link between is searched by referring to the link table 2c. This makes one secondary MB
Ends when is searched for. If the secondary MB of the priority type is not detected, the other type secondary MB extraction means 1e is activated and the secondary MB is searched for another type different from the priority type by referring to the link table 2c. As a result, one secondary MB can be searched.

However, when both the primary MB and the tertiary MB are even numbers (old numbers) and an odd number (young number) is selected as the priority type, the odd number is selected by the priority type secondary MB extraction means 1d. When it is not possible to search, if an even-numbered (old number) secondary MB is selected by the secondary-type secondary MB extraction means 1e, three even-numbered numbers are selected, but this leaves no room in the path. This is acceptable when, for example, it is necessary to provide the subscriber with a path connection.

In this way, the connection path passing through each of the primary to tertiary switch sections always passes through an odd number (young number) having a low resistance value in one MB.

[0034]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 2 is a processing flow of route selection of a secondary MB according to the embodiment. In advance, the accommodation position including the number of the primary MB of the subscriber line that is the target of MDF path connection,
1 according to the accommodation position including the number of the third MB of the subscriber circuit
It is assumed that the type of the next MB and the type of the tertiary MB are identified.

When the free route extraction process via the secondary MB starts, one of the three processes is executed depending on the combination of the types of the primary MB and the tertiary MB. That is,
When both the primary MB and the tertiary MB are even numbers (old numbers), the selection start secondary MB is set to an odd number (young numbers) (S in FIG. 2).
1). This odd number corresponds to the priority type described in FIG. Next, when one of the primary MB and the tertiary MB is an even number and the other is an odd number, the secondary MB to be searched may be any type, but the selection start secondary MB is set to the previous empty route. The number next to the number of the secondary MB selected in the extraction process is set (S2 in FIG. 2). If both the primary MB and the tertiary MB are odd numbers (young numbers), the selection start secondary MB is set to an even number (old number) (S3 in FIG. 2).

When the selection start secondary MB is determined by any of the above S1 to S3, the selection start secondary MB is changed to 1 from the selection start secondary MB.
The route is skipped (one MB is sequentially skipped) and the route is extracted (S4 in FIG. 2). In this case, the link between the primary MB accommodating the subscriber line and the secondary MB to be selected, and the secondary MB to be selected and the tertiary MB accommodating the subscriber circuit
It is determined whether or not there is an empty space (empty route) for each of the links between them by referring to the link table 22 shown in FIG.
S5), if there is an empty route, the secondary MB is extracted.

If there is no empty route, it is judged whether the route extraction for the secondary MB has completed one cycle (see S
6), if not completed, return to S4 and target secondary M
Change B's number to one skipped. As a result, when starting with an even number (odd number) in S4 of FIG.
The next target secondary MB moves to the next even-numbered (odd-numbered) secondary MB, and similar free route determination is performed for the secondary MB.

When all the secondary MBs belonging to the type (even number or odd number) of the selection start secondary MB have completed one round of route extraction, the route extraction is performed one by one from the start secondary MB (Fig. 2 S7). That is, when the start secondary MB is an even number (odd number), the route extraction is performed by using the odd number (even number) secondary MB next to the secondary MB as the start secondary MB in S7, and an empty route is obtained. It is determined whether there is any (S8 in FIG. 2). If there is an empty route, the secondary MB is extracted, and if there is no empty route, it is determined whether the route extraction has made two rounds (S9 in FIG. 2). If not, the process returns to S7 and the same empty route is extracted for the secondary MB having the skipped number. When the route is extracted twice, the route busy is output and the process ends.

When selecting a secondary MB of the MDF, a secondary MB allocation algorithm (called a secondary MB selection allotter) has been conventionally used to evenly use each MB. This is because the difference points of the secondary MBs are arranged at a high density, so that it is possible to avoid arranging a large number of connecting pins (inserting at the difference points) biased to some secondary MBs. It has a function of selecting a candidate of the position (number) of the secondary MB suitable for the next use based on the usage state of the MB.

The present invention can be implemented by the processing algorithm shown in FIG. 2 when a candidate for a secondary MB is selected by this conventional algorithm for selecting a secondary MB. Explain.

3 and 4 are explanatory views (No. 1) and (No. 2) of a concrete example showing the secondary MB selection order. 3 and 4
, 10-n represent a plurality of sets MB forming the secondary switch unit, and in this example, n sets MB are provided. In each set MB, 11 is an even (old) secondary MB, 12 is an odd (young) secondary MB, and the top set MB10-1
Nos. 0 and 1 (represented by # 0 and # 1) are set in the secondary MBs 11 and 12 of each of
As shown in FIGS. 3 and 4, for the secondary MBs 11 and 12 of −2, ..., Numbers 2, 3, 4, 5, 5, 6, 7 ,.
The numbers 2 (n-1) and 2n-1 are set.

FIG. 3 shows a case in which the secondary MB of # 3 (odd number, young number) is selected by the secondary MB selection alloter, and the odd number (young number) is selected as the priority type in the processing flow of FIG. The order of the selection process of (1) is shown, and each of the sequential processes of (-) are not outlined below.

First, the secondary MB selection position by the secondary MB selection allotter is # 3, and when the younger number (odd number) is determined as the priority type in step S1 of FIG. 2, both are odd numbers. To match, so select start position # 3
The extraction of the route is started by the secondary MB of # 3 as the secondary MB of # 3.

If the route is not extracted for the secondary MB of # 3, one is skipped next and the same processing is performed for the secondary MB of # 5. Below, all odd-numbered secondary M until the route is extracted
The extraction is performed for B, and the processing ends when the extraction is performed.

If extraction fails for all odd (younger) secondary MBs of # 3, # 5, ... # (2n-1), # 1,
Even-numbered 2 after the first selection start position (# 3) above
Extraction is started from the next MB (# 4).

If extraction fails in the secondary MB of # 4, all even-numbered secondary MBs (# 6, # 8, ..., # 0, # 2)
The route is extracted until it succeeds, and when it can be extracted, the extraction process ends.

When the extraction fails in # 2, the extraction process is terminated and the root busy is output. FIG. 4 shows a selection process when the # 0 (even number, old number) secondary MB is selected by the secondary MB selection alloter and the odd number (young number) is selected as the priority type in the processing flow of FIG. Indicates the order of
Each sequential process (not shown) is outlined below.

First, the secondary MB selection position by the secondary MB selection allotter is # 0, and step S1 in FIG.
If the odd number (younger number) is determined as the priority type by (or S2), the two do not match in the odd number and the even number. Therefore, the selection start position number 0 Is incremented by 1 to make # 1 the selection start position. The extraction of the route is started in the secondary MB of # 1.

If the route is not extracted for the # 1 secondary MB, the same process is performed for the next skipped # 3 secondary MB. Below, all odd-numbered secondary M until the route is extracted
The extraction is performed for B, and the processing ends when the extraction is performed.

If extraction is failed in all odd (younger) secondary MBs of # 1, # 3, ... # (2n-1), the next even number after the first selection start position (# 1) above. Second MB
Extraction is started from (# 2).

If the extraction fails in the # 2 secondary MB, route extraction is performed until all the even-numbered secondary MBs (# 4, # 6, ..., # 0) succeed. To finish.

When the extraction fails at # 0, the extraction process is terminated and the root busy is output. Although FIGS. 3 and 4 have described the case where the priority type is an odd number, the secondary MB selection order is also based on the same principle when the priority type is an even number (step S3 in FIG. 2). Is controlled.

In step S2 of the process flow for route selection shown in FIG. 2, if the primary is old and the tertiary is young or the primary is young and the tertiary is old, "start selection 2 Next M
"B is next to the previous selection", but when the position (number) of the secondary MB is selected by the secondary MB selection alloter, the position (number) of the selected secondary MB is an even number or an odd number. The route extraction process can be started from that position regardless of the position.

FIG. 5 shows the distribution of the cumulative MB resistance value when 3 even numbers (old numbers) are avoided according to the present invention. This corresponds to FIG. 12 described above, and there are 3 even-numbered M's in the path passing through the matrix board of each of the primary to tertiary switch sections.
The distribution of the cumulative resistance value is shown for 2000 paths without including the path passing through B. The vertical axis represents the number of paths and the horizontal axis represents the cumulative resistance value of the three matrix boards. As is clear from comparison with the maximum resistance value distribution in the case of including the even-numbered 3 shown in FIG. 12, the path connection resistance can be reduced by about 2.6Ω on average. In the case of FIG. 5, the maximum value is 10.1Ω, and even if the resistance value of the back wired board (BWB) of 8Ω is added, it is 18.1Ω and can satisfy the standard (20Ω or less).

In the above description, an example in which two MBs are provided on the aggregate matrix board is shown, but more M
Also in the MDF using the aggregate matrix board containing B, the path resistance can be reduced by the same principle.

FIG. 6 shows an example of an aggregate matrix board on which many MBs are mounted. In this example, a total of 16 MBs # 0 to # 15 are provided in one aggregate matrix board. In this case, it is far from the connector #
0, # 4, # 8 and # 12 boards are used as old numbers, and other M
B (# 1 to # 3, # 5 to # 7, # 9 to # 11, # 13 to
# 15) is all young. When such an aggregate matrix board is configured as the primary to tertiary switch parts of the MDF, the resistance value of the path can be reduced by avoiding connections that are all old in the three switch parts according to the principle of the present invention. It can be reduced.

[0057]

According to the present invention, in the MDF which connects the subscriber line to the circuit of the exchange through the path through the three-stage switch section using the aggregate matrix board having a plurality of matrix boards mounted therein, the three-stage switch section is provided. It is possible to reduce the resistance value of each connection path via the fixed value to a certain value or less. As a result, the signal quality of all subscriber lines is improved by MDF.
Can be maintained above a certain level.

[Brief description of drawings]

FIG. 1 is a principle configuration diagram of the present invention.

FIG. 2 is a diagram showing a processing flow of route selection of a secondary MB according to the embodiment.

FIG. 3 is an explanatory diagram (part 1) of a specific example showing a secondary MB selection order.

FIG. 4 is an explanatory diagram (part 2) of a specific example showing a secondary MB selection order.

FIG. 5 is a diagram showing a distribution of MB cumulative resistance values when the third even number (old number) is avoided according to the present invention.

FIG. 6 is a diagram showing an example of an aggregate matrix board on which many MBs are mounted.

FIG. 7 is an explanatory diagram of functions of the MDF system.

FIG. 8 is a diagram showing a configuration example of a conventional MDF.

FIG. 9 is an explanatory diagram of a relationship between switch units.

FIG. 10 is a diagram showing a configuration of an aggregate matrix board on which two MBs are mounted.

FIG. 11 is an explanatory diagram of a connection path of the MDF when a collective MB having two MBs is connected to a back wired board.

FIG. 12 is a diagram showing a distribution of cumulative resistance values when the first to third switch sections all include path connections passing through even-numbered (old number) MBs.

[Explanation of symbols]

1 processing unit 1a Subscriber accommodation primary MB type identification means 1b Subscriber circuit accommodating third MB identifying means 1c Priority secondary MB type selection means 1d Priority type secondary MB extraction means 1e Other type secondary MB extraction means 2 memory 2a accommodation table 2b discrimination table 2c link table

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Naoto Kaneko 3-9-18 Shin-Yokohama, Kohoku-ku, Yokohama-shi, Kanagawa Prefecture Fujitsu Communication Systems Limited (72) Masao Hosogai Inoue Ueda, Nakahara-ku, Kawasaki-shi, Kanagawa 4-1-1 1-1 Fujitsu Limited (72) Inventor Riei Takada 4-1-1 Kamiotanaka, Nakahara-ku, Kawasaki-shi, Kanagawa Fujitsu Limited (56) Reference JP-A-2-246458 (JP, A) ) JP-A-8-307910 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) H04Q 1/00-1/16

Claims (3)

(57) [Claims] 1. In an MDF system for forming a connection path via a three-stage switch unit for connecting a subscriber line to a subscriber circuit of a switchboard, each switch unit includes a plurality of matrix boards. Each matrix board is provided with a plurality of vertical and horizontal lines and a difference point hole for forming a connection path by inserting a connecting pin at each difference point. A connector connected to each wire by wiring at the end, and a structure in which the connector is connected to a back wired board to connect to other switch parts and lines, and the position near the connector in the aggregate matrix board Set the matrix boards placed in 1 and 2 as odd numbers and the matrix boards placed in distant positions as even numbers. In the selection of the connection path passing through the switch section, the secondary switch section and the tertiary switch section, at least one of the aggregate matrix boards among the primary switch section to the tertiary switch has a low resistance odd number matrix board. A method for reducing the path connection resistance of an MDF system, characterized in that a path passing through is selected. 2. The odd-numbered or even-numbered type of matrix board accommodating a subscriber line to which the aggregate matrix board of the primary switch section is connected according to claim 1,
The matrix board of the primary switch section and the tertiary switch section is identified by identifying the type of the odd-numbered or even-numbered matrix board in which the subscriber circuit to be connected to the subscriber line of the aggregate matrix board of the next switch section is accommodated. The path connection of the MDF system, characterized in that the type of matrix board of the aggregate matrix board of the secondary switch units for connecting between and is preferentially selected as a type in which at least one of the three switch units is an odd number. Resistance reduction method. 3. The method according to claim 2, wherein when one of the odd-numbered or even-numbered matrix boards of the secondary switch section is selected with priority, the matrix boards between the primary switch sections and Check if the path between the tertiary switch units is free, and if there is a free space, extract that matrix board. If it is not extracted from any of the matrix boards of the applicable type, then it will be extracted for each matrix board of another type. A method for reducing path connection resistance in an MDF system, which comprises: