JP3398678B2 - Switching method - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a switching system, and more particularly to a switching system for distributing a plurality of subscriber line signals over different service types, and more particularly, to a time-division multiplexed access side highway channel for the service. The present invention relates to a channel integrated switching system in which each type and signal type are distributed to a plurality of node-side highways.

[0002]

2. Description of the Related Art In a digital exchange, a channel on an access side highway in which subscriber line signals of different service types are time-division multiplexed is used in a node side highway corresponding to the service type. Are distributed. Conventionally, when performing such distribution, first, a plurality of types of channels on the access-side highway are separated into signal types such as voice / data and control signals, and then service types are distributed for each of these signal types. Was there.

FIG. 6 shows the configuration of such a conventional switching system. The conventional switching system includes an access system termination circuit 62 and two switching circuits 631 and 632.
And switch control circuits 641 and 642, and two node system termination circuits 191 and 19 corresponding to the service type.
It consists of two. For simplification, a case where an analog subscriber line and an ISDN subscriber line are accommodated as different service types will be described as an example. In FIG. 6, an access system device 60 time-division-multiplexes subscriber line signals of different service types, that is, digitized analog subscriber line signals and ISDN subscriber line signals, and a transmission line 61 called a highway (HW). Send to. The time division multiplexed subscriber line signal on the access side HW 61 is
It is composed of multiple types of channels such as voice / data and control signals.

An access system terminating circuit 62 which receives a time-division multiplexed subscriber line signal through the access side HW 61.
Separates the subscriber line signal composed of the plurality of types of channels into signal types, that is, voice / data and control signals. The voice / data separated by the access system termination circuit 62 is input to the switching circuit 631, and the control signal is input to the switching circuit 632. In the conventional switching system, these two switching circuits 63
Numerals 1 and 632 are TSTs in which a time switch (T) and a space switch (S) are combined to secure the capacity of the communication path.
It is common to have a three-stage configuration.

The switching circuits 631 and 632 are
Controlled by switch control circuits 641 and 642, respectively, voice / data and control signals are assigned to respective service types. That is, the switching circuit 631 is
The voice / data distributed to each service type is transferred to the first node system termination circuit 1 8 1 corresponding to the analog subscriber line.
And second to nodes based termination circuit 1 8 2 corresponding to the ISDN subscriber line, and outputs via the node side HW651a and 651b. Similarly, the control signal is also output to the first node system termination circuit 1 8 1 and the second node system termination circuit 1 8 2 via the node side HWs 652a and 65 2 b. And these two node system termination circuits 1
Reference numerals 8 1 and 1 8 2 denote the channels assigned to the service types for each signal type as described above, the analog subscriber dedicated node device 191 and the ISDN subscriber line node device 19 respectively.
2 according to a predetermined format.

[0006]

However, in the conventional switching system, since the subscriber line signals are distributed for each signal type, an access system for separating the time-division-multiplexed subscriber line signals for each signal type. The terminating circuit 62 is required before the switching circuit. Moreover, a plurality of switching circuits are required, and a plurality of switch control circuits for controlling these switching circuits are also required. Furthermore, when performing distribution, these switching circuits 631, 63
Since it is necessary to synchronize the two, a synchronization circuit (not shown in FIG. 6) must be provided. As a result, the circuit configuration becomes complicated, and the amount of hardware increases, resulting in a high system price. In particular, when the switching circuit has a three-stage configuration of TST, the circuit configuration, particularly the control circuit is complicated and the system price is increased.

The present invention has been made to solve such a problem, and an object thereof is a channel integrated switching system for distributing time division multiplexed subscriber line signals composed of a plurality of types of channels. Is realized with a relatively simple circuit configuration, and a switching system is provided at a lower cost.

[0008]

To solve the problems described above SUMMARY OF THE INVENTION The switching system according to the present invention may be time-division multiplexed plurality of subscriber line signals across different service type is, signals of the subscriber line signal Type of voice / data
The channel and the subscriber line signal are classified as control signals.
Access-side highway (HW) paired with a channel
And a plurality of node-based termination circuits or dedicated line connection devices corresponding to the service types are provided for the voice / data
Highway where the data channel is distributed and the control
The highway where the signal channels are distributed
That a plurality of node side highway (HW), wherein accommodates the access side HW and the node side HW, and a switching circuit for switching connection between said node side HW with the access side HW, the of the switching circuit Access side H
W and consists of a switch control means for controlling a connection state between the node side HW, before Symbol switch control means, specifies a connection path of the switching circuit in response to the signal type of the service type and the channel And a holding memory for storing the connection path designated by the communication path control means, and the access side HW of the switching circuit and the node according to the connection path stored in the holding memory. It is characterized in that the connection state with the side HW is controlled.

The connection state of the switching circuit is uniquely determined by the contents stored in the holding memory, that is, the connection path. In the present invention, the communication path control means manages the contents of the holding memory based on the service type and the signal type. Therefore, the channel located in the predetermined TS of the access side HW is set to the predetermined T of the predetermined node side HW for each service type and each signal type.
It can be exchange-connected to S. As a result, channels can be distributed without separating the time-division-multiplexed subscriber line signal on the access side HW into signal types. Therefore, a plurality of types of channels including a plurality of signal types can be distributed by one switching circuit. As a result, there is no need to separate the signal types, and there is no need to provide a separation circuit such as the access system termination circuit 62 (FIG. 6) in the preceding stage of the switching circuit. Moreover, since it is not necessary to synchronize switching between signal types, a synchronization circuit is not required.

In the present invention, the service type means the type of service determined by the subscriber line signal standard. Specifically, analog subscriber line signals, ISDN
In addition to the difference between the subscriber line signal and the leased line signal, if the communication medium such as electricity and light and the transmission speed are different, they are treated as different service types. The signal type refers to the type of information contained in the subscriber line signal, and specifically includes voice / data signals and control signals. Further, in the switching system according to the present invention, the channels distributed to the node side HW accommodated in the switching circuit are
In addition to being output to the node system device corresponding to each service type via the node system termination circuit, even if the dedicated line is accommodated, even if it is directly output to the dedicated line connection device that is the node system device. good.

With the recent development of LSI technology, it has become possible to configure a large-capacity switching circuit with one time switch. In view of this, the switching method according to the second aspect of the present invention is characterized in that the switching circuit has a T1 stage configuration. In addition to simplifying the configuration of the switching circuit itself by configuring the switching circuit in the T1 stage configuration as described above, the switch control circuit can also be configured by one holding memory. The system configuration, especially the configuration of the control circuit, is simpler than in the case of the stage configuration.

In the switching system according to the present invention, the switch control means, particularly the communication path control means, is such that if the connection path between the access side HW and the node side HW is uniquely determined, the connection path of the switching circuit May be specified in any manner. For example, as in the invention described in claim 3, the time slots of a plurality of subscriber line signals which are time-division-multiplexed comply with a predetermined access side HW format, and a predetermined channel distribution destination is included in the time slot. The predetermined time slot of the node-side HW format may be determined in advance based on the service type and signal type of the channel.

In the present invention, the node system terminating circuit converts a series of channels distributed as described above into a predetermined format and sends it to the node system device corresponding to each service type. The invention described them in claim 4, the node system termination circuit, upper Symbol the switching circuit in accordance with the above keno over de side HW format
The plurality of types of channels allocated to node side HW, a switching method characterized by mapping the SD H off Oma'<br/> preparative for each of the corresponding service type.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing a first embodiment of the present invention. As shown in FIG. 1, the switching system according to the present embodiment has an access-side HW 11 and node-side HWs 16a, 16b, 17a, 17.
b, and a switching circuit 12 of T1 stage having a communication memory for temporarily storing the time division multiplexed signal input from the access side HW, and a switch control constituting a switch control means for controlling the switching circuit 12. Circuit 13, speech path controller 14 and workstation 1
It is composed of 5. Here, the switch control circuit 13
Includes a holding memory (not shown), and controls exchange connection of the switching circuit 12 of the T1 stage based on the stored contents of the holding memory as described later. Further, the call path control device 14 and the workstation 15 constitute a call path control means.

An access system device 10 for time-division multiplexing and transmitting digital subscriber line signals covering different service types is connected to the switching circuit 12 via the access side HW 11. Here, the access system device 10 together with the terminal on the subscriber side collects, for example, a subscriber line interface device for converting an analog signal from the subscriber into a digital signal, a digitized subscriber signal or an ISDN subscriber signal. It shall include a concentrator for multiplexing. Further, a synchronous terminal device that connects to a trunk line connecting other exchanges can be considered as one of the access system devices. Also, the node side H
Node terminating circuits 181 and 182 corresponding to the analog subscriber line node system device 191 and the ISDN subscriber line node system device 192 are connected via W16a, 16b and W17a, 17b, respectively. In the following description, it is assumed that analog subscriber line signals and ISDN subscriber line signals are handled as different service types.

Next, channel allocation will be described. The access system device 10 time-division-multiplexes the digitized analog subscriber line signal and ISDN subscriber line signal according to the access side HW format shown in FIG.
It is sent to the switching circuit 12. In the switching circuit 12, the connection state of the switching circuit 12 in the T1 stage is controlled by the switch control means composed of the switch control circuit 13, the communication path control circuit 14, and the workstation 15, thereby performing time division. The channels of the multiplexed subscriber signal are distributed, and the access side HW format shown in FIG. 2 is converted into the node side HW format as shown in FIG. Note that FIG.
HW # 0, HW # 1, HW # 2, HW # 3 in
Each of the node-side HWs 16a, 16b, 17a in FIG.
It corresponds to 17b.

According to FIG. 3, HW # 0 and HW # 1 are voice / data and control signals of analog subscriber line signals, respectively, and HW # 2 and HW # 3 are voice / data of ISDN subscriber line signals, respectively. Data and control signals. In this way, the channels assigned to each service type and each signal type are assigned to the node system termination circuits 181 and 18 for each service type.
2, the voice / data and the control signal are mapped in the SDH format, and the analog subscriber line node system device 191 and the ISDN subscriber line node system device 19 respectively.
2 is sent.

The control of the connection state in this embodiment is as follows. This will be described below with reference to the conceptual diagram of FIG. That is, the workstation 15 determines the service type (analog subscriber line or ISDN subscriber line) and signal type (voice / data or control signal) of the channels constituting the time division multiplexed subscriber line signal on the address side HW 11. ) Is sent to the speech path control device 14, and the speech path control device 14
The contents of the holding memory forming the switching circuit 13 are changed according to the path setting order from the workstation 15.

More specifically, the workstation 15
Is a time slot (T of the access side HW determined in advance based on the service type and the signal type described above).
S) A path setting order that specifies the number and the TS number of the node side HW is sent to the communication path control device 14. In this way, the path is uniquely determined by designating the TS number of the access-side HW and the TS number of the node-side HW. Then, the workstation 15 continuously outputs such a path setting order. In accordance with the path setting order received from the workstation 15, the speech path control device 14 sends data representing the address corresponding to the TS number of the access side HW to be connected and the TS number of the node side HW to the switch control circuit 13. Stored in the holding memory.
More specifically, the address mentioned here represents the address of the communication memory of the switching circuit 12 in which the channel of a predetermined TS is stored, and the data reads the channel stored in the memory area designated by the address. Represents the destination. Therefore, in other words, the call path control device 14 outputs the pair of the TS number of the access side HW and the TS number of the node side HW input from the workstation 15 as the address on the call memory of the actual switching circuit 12. It has a function of converting to data representing the destination. Such an operation can be realized by using, for example, a look-up table.

As described above, in the present embodiment, the contents of the holding memory, that is, the address / data, which constitutes the switch control circuit 12 by the speech path control device 14 and the workstation 15, are based on the service type and the signal type of the channel. The channel of the TS number of the access side HW determined by the address is changed to the T of the node side HW determined by the data.
The connection state of the switching circuit 12 can be controlled so as to be assigned to the S number. As a result, the time-division-multiplexed subscriber line signal composed of a plurality of types of channels is converted into service type (analog subscriber line or IS
It can be sorted according to the DN subscriber line) and the signal type (voice / data or control signal). The signal transmission from the node devices 191 and 192 to the access device 10 is the reverse of the above operation.

In the switching method according to the present embodiment, since the switching circuit 12 distributes a plurality of types of channels, neither a circuit for separating the signal types nor a synchronizing circuit is required. In addition, the switching circuit 12 is T
Since it is configured by one stage, the system configuration is simplified centering on the control circuit as compared with the conventional one, and the switching system can be provided at low cost.

Next, a second embodiment of the present invention will be described with reference to FIG. In the switching system according to the present embodiment, the service types accommodated in the switching circuit are the analog subscriber line and the I type handled in the first embodiment.
There is a leased line in addition to the SDN subscriber line.

FIG. 5 is a block diagram showing the configuration of the switching system according to the second embodiment. The same parts as those in the first embodiment described above are designated by the same reference numerals, and detailed description thereof will be omitted. As shown here, the switching circuit 22 accommodates the dedicated line node side HW 23 connected to the dedicated line connection device 24. The access side HW 11 and the node side HWs 16a and 16b corresponding to the analog subscriber line and the node side HWs 17a and 17b corresponding to the ISDN subscriber line are accommodated, which is the same as the first embodiment described above. . The access system device 20 time-division-multiplexes the digitized analog subscriber line signal, ISDN subscriber line signal, and dedicated line signal according to a predetermined access system HW format, and sends them to the access side HW.

The switching circuit 22 is composed of a T1 stage. More specifically, the switching circuit 22 includes a forward (access system HW to node system HW
(Switch connection to the access system HW) and a T1 stage time switch for backward (switch connection from the node system HW to the access system HW). These T1
The time switch of the step is a sequential light (Sequenti
al Write), Random Read (Random Read), Random Write (Random Write), Sequential Read (Se
However, in the case of accommodating two or more access side HWs, in order to perform flexible exchange connection control, it is desirable to use random write (Rand).
It is desirable that om Write) and random read (RandomRead) are possible. Further, the switching circuit using the time switch as described above can be realized by an LSI including a call memory.

Also in this embodiment, as in the first embodiment, the switch control means is the switch control circuit 1
3. Call path controller 14 and workstation 15
Composed of. The control method is also the workstation 15
Is the time slot (TS) number of the access side HW and the node side which are predetermined based on the service type (analog subscriber line, ISDN subscriber line or leased line) and signal type (voice / data or control signal). HW
Of the access side HW to be connected according to the path setting order.
An address corresponding to the number and data representing the TS number of the node side HW are stored in a holding memory (not shown) of the switch control circuit 13, and the switch control circuit 13 controls the connection state of the switching circuit based on the stored contents of the holding memory. This is the same as the first embodiment described above. In this way, by changing the contents of the holding memory according to the service type and the signal type, distribution of various channels is realized.

As described above, in the switching system according to the present embodiment, channels are distributed by one switching circuit. Therefore, a separation circuit for separating the time-division multiplexed subscriber line signal for each signal type or a plurality of A synchronizing circuit for synchronizing the switching circuits of is unnecessary. Therefore, the switching method can be realized with a simple circuit configuration.

In the above embodiment, analog subscriber lines, ISDN subscriber lines, and leased lines are exemplified as service types for the sake of simplicity. However, in addition to the analog / digital difference, The service type is also distinguished by the transmission rate, the interface (optical interface or electrical interface), and the service content (ISDN, PHS, etc.). Further, although the description has been given assuming that the number of the access system HW accommodated in the switching circuit is one, in the switching system according to the present invention, the TS of the access system HW is
As long as the connection path between the number and the TS number of the node system HW can be designated, it is possible to accommodate a plurality of access system HWs in the switching circuit.

[0028]

As described above, according to the present invention, one channel integrated switching system for distributing time-division-multiplexed subscriber line signals composed of a plurality of types of channels can be provided without separating them into signal types. It is not necessary to provide a separation circuit for separating the subscriber line signal for each signal type in the preceding stage of the switching circuit because it can be realized by the switching circuit of the above, and a synchronization circuit for synchronizing a plurality of switching circuits is unnecessary. Therefore, the hardware configuration becomes simple. Since the system can be configured with a relatively simple circuit configuration, it is possible to provide the switching system at a lower cost.

According to the second aspect of the invention, since the switching circuit has the T1 stage configuration, the switch control circuit can also be configured by one holding memory, and the hardware configuration of the switching system, especially The configuration of the control circuit becomes simple.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a switching system according to a first exemplary embodiment of the present invention.

FIG. 2 is an access side H in the switching method.
It is a figure which shows an example of W format.

FIG. 3 is a node side HW in the switching method.
It is a figure which shows an example of a format.

FIG. 4 is a conceptual diagram for explaining a control method in the switching method.

FIG. 5 is a block diagram showing a configuration of a switching system according to a second exemplary embodiment of the present invention.

FIG. 6 is a block diagram showing a configuration example of a conventional switching method.

[Explanation of symbols]

10, 20 ... Access system device, 11 ... Access side HW,
12, 22 ... Switching circuit, 13 ... Switch control circuit, 14 ... Speech path control device, 15 ... Workstation, 16a, 16b, 17a, 17b, 23 ... Node side HW, 181, 182 ... Node system termination circuit, 191, 1
92 ... Node system device, 24 ... Dedicated line connection device.

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yuki Kato 3-19-2 Nishishinjuku, Shinjuku-ku, Tokyo Nihon Telegraph and Telephone Corporation (72) Inventor Tadashi Mine 3-chome, Nishishinjuku, Shinjuku-ku, Tokyo 19 No. 2 Nihon Telegraph and Telephone Corp. (72) Inventor Tsutomu Kashiwagi 3-19-2 Nishishinjuku, Shinjuku-ku, Tokyo Nihon Telegraph and Telephone Corp. (56) References JP-A-8-70348 (JP, A) JP-A-9-23491 (JP, A) JP-A-63-127696 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) H04Q 11/04 H04M 3/00 H04Q 3 / 545

Claims (5)

(57) [Claims] 1. A signal of a subscriber line signal , wherein a plurality of subscriber line signals covering different service types are time-division multiplexed.
Types of voice / data channels and subscriber line signals
An access-side highway whose signal type is paired with a channel of a control signal, and a plurality of node system termination circuits or dedicated line connection devices corresponding to the service types are provided for each of the voice / data
Highway to which channels are distributed and the control signal
And a node-side highway multiple <br/> number consisting of a highway channel is distributed in the housing the access side highway and said node side highway, switched connection between said node side highway with the access side highway a switching circuit for, consists of a switch control means for controlling a connection state between the access side highway and the node side highway of the switching circuit, before Symbol switch control means, the service type and the signal type of the channel Corresponding to the communication path control means for designating a connection path of the switching circuit, and a holding memory for storing the connection path designated by the communication path control means, and the connection path stored in the holding memory. According to the access side highway of the switching circuit Switching method, characterized by controlling the state of connection between the serial node side highway. 2. The switching method according to claim 1, wherein the switching circuit is composed of a T1 stage time switch. 3. The switching system according to claim 1, wherein the time slots of the plurality of time division multiplexed subscriber line signals are in accordance with a predetermined access side highway format, The control means designates the connection path by predetermining a predetermined time slot of a predetermined node-side highway format as a distribution destination of a channel included in the time slot based on a service type and a signal type of the channel. Switching method characterized in that. 4. The switching system according to claim 3, wherein the node system termination circuit corresponds to the plurality of types of channels distributed to the node side highway by the switching circuit according to the node side highway format. A switching method characterized by mapping to the SDH format for each service type. 5. A switching system according to any one of claims 1 to 4, wherein a plurality of subscriber line signals over the different service types are provided.
Is a switching system including an analog subscriber line signal and an ISDN subscriber line signal .