JP3213075B2 - Digital exchange - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a digital exchange, and more particularly, to providing a subrate exchange trunk for performing compression encoding and decoding and exchanging, and an address storage means and a subrate exchange trunk management means. A digital exchange that enables subrate switching to be applied to public networks.

[0002]

2. Description of the Related Art In a conventional digital exchange, data is transmitted from one communication terminal to a remote station by using one channel of the line as it is to perform communication. Further, in a digital exchange capable of sub-rate exchange, it is possible to multiplex data from a plurality of low-speed communication terminals into one time slot to communicate with a game terminal, but does not perform compression encoding. If data of a channel capacity of one channel is transmitted from a communication terminal connected to the exchange, communication is performed between the opposite terminal and one channel. FIG.
FIG. 2 is a diagram illustrating an exchange system using a conventional digital exchange. 64 kbps, 64 kb from communication terminals 11a to 11e, respectively
The data of ps, 2400 bps, 1200 bps and 64 kbps are multiplexed by the multiplexer (MUX) 13 of the digital exchange 12 to 64 kb.
Transmitted as ps data.

[0003] In a time-division digital exchange, data exchange is generally performed in units of 8 bits, but all bits in such data may not be valid. In such a case, transmission and reception are performed by multiplexing only the valid data in the 8 bits, and the exchange performs bit-by-bit exchange, that is, sub-rate exchange.
It is desired to improve the line utilization efficiency. Further, it is desired that the subrate exchange trunk in this case can reduce transmission delay even in tandem connection.

For example, the "sub-rate switching system" proposed in Japanese Patent Application Laid-Open No. 4-79444 improves the line utilization efficiency of a digital communication network by providing a sub-rate switching trunk for performing flexible bit-by-bit switching. The present invention also relates to a sub-rate switching system that can reduce transmission delay even in tandem connection. That is, in a time-division digital switch of a system in which data from a plurality of low-speed data terminals are inserted into a time slot consisting of a predetermined number of bits in a high-speed format and transmitted, only valid bits are converted from the plurality of low-speed data converted to the high-speed format. Is extracted and multiplexed in a time slot of one channel consisting of the predetermined number of bits.
A sub-rate exchange trunk for performing reverse processing and separating is provided, and the time division digital exchange transmits the multiplexed time slots to the opposite station, and separates the multiplexed time slots from the opposite station to a plurality of low-speed It is configured by transferring to a data terminal.

[0005]

As described above, in the conventional digital exchange, even if the data from the communication terminal that transmits the data of the channel capacity for one channel is data that can be compression-encoded, Since communication is performed between stations using a line for one channel, the line utilization efficiency does not increase, and when calls are frequently generated, there is a problem in that the call loss rate increases. Also, when applying sub-rate exchange to a leased line, it is assumed that sub-rate exchange is performed with a game. However, when applying sub-rate exchange to a public network, It is necessary to determine whether or not it is compatible with sub-rate exchange, and it is impossible for a conventional digital exchange to make that determination. Furthermore, when sub-rate exchange is applied in a public network, there is a possibility that a sub-rate exchange connection will be established between multiple points. In such a case, the usage status of the sub-rate exchange trunk is constantly monitored, and if available, the sub-rate exchange call is made. If the connection cannot be used, it is necessary to make a normal call connection, and the conventional digital exchange has a problem that it is impossible to make the judgment.

[0006] The present invention has been made in view of such circumstances, and performs sub-rate exchange on data from a communication terminal connected to a digital exchange.
It is an object of the present invention to provide a digital exchange capable of improving line utilization efficiency and applying sub-rate exchange to a public network.

[0007]

Means for Solving the Problems The present invention, in order to achieve the above object, (1) is converted into low-speed data by compression coding the data from a plurality of communication terminals connected, the number of the predetermined bit A sub-rate switching trunk for multiplexing into one-channel time slots consisting of: separating low-speed data from multiplexed time slots transmitted from a game station and decoding compression-coded low-speed data; with transmission to the remote station a multiplexed time slot interchange trunk, transmits the multiplexed time slots from an opposite station to a plurality of communication terminals perform separation and decoding in the subrate exchange trunk Digi
In a central exchange, a trunk manager for subrate exchange
Set up a stage and use the sub-rate exchange trunk of your own station.
Information about the game, and connect to the game.
By checking the usage status of the trunk for
Whether a subrate exchange trunk is available or not
Judge whether it is capable
Subrate switched calls, if a switching trunk is available
Negotiate the connection with the game
For exchange of subrate of own station and / or opponent
Subrate switched call if trunk is unavailable
Between the game and the normal call connection without connecting
In negotiation to be carried out normal connection, furthermore, (2) in the (1), the address storing means for storing the address of the opposite station having the subrate exchange trunk provided, the transmission request data from the communication terminal When this occurs, it is determined whether or not the game requesting the transmission has a sub-rate exchange trunk by comparing the information in the address storage means with the address, and the game has a sub-rate exchange trunk. In such a case, the data is compressed and encoded by the sub-rate exchange trunk, multiplexed in a time slot and transmitted to the terminal.If the terminal does not have a sub-rate exchange trunk, the data is transmitted to the sub-rate exchange trunk. (3) In the above (2), the address is transmitted to the game without any intervention.
Storage means for storing rewritable information content
Means .

[0008]

According to the present invention, by providing a subrate exchange trunk for compressing and encoding data from a communication terminal and multiplexing the data into time slots, it is possible to greatly improve the line utilization efficiency. Also, by providing address storage means for storing the address of a game having a trunk for subrate exchange, it is possible to determine whether or not the game is capable of subrate exchange, and even when the digital exchange of the present invention is applied to a public network. Subrate exchange can be applied. Further, by providing the sub-rate exchange trunk management means, from the information on the use status of the sub-rate exchange trunk stored in the management means,
It is possible to determine whether the trunk for subrate exchange can be used or not, and to apply subrate exchange in a public network in which there is a possibility that a subrate exchange call is connected between multiple points.

[0009]

Embodiments will be described below with reference to the drawings. FIG. 1 is a block diagram for explaining one embodiment of a digital exchange according to the present invention, and FIG. 2 is a diagram for explaining a sub-rate switching system. In the figure, 1a to 1d are communication terminals, 2 is a digital exchange, 3 is an extension line I / F.
(Interface), 4 is a communication control unit, 5 is address storage means, 6 is subrate exchange trunk management means, 7
Is a trunk for subrate exchange, 7a is compression encoding / decoding means, 7b is a MUX / DMUX, and 8 is an external line I / O.
F (interface). The subrate exchange trunk 7 performs compression encoding and multiplexing of data from the communication terminals 1a to 1d, and compression encoding / decoding means 7 for separating and decoding data from a game terminal.
a. The multiplexed data is transmitted to the game, and the decoded data is transmitted to each communication terminal connected to the exchange.

First, a case where a data transmission request is issued from the communication terminals 1a to 1d will be described. When a data transmission request is issued to an external line from the communication terminals 1a to 1d connected to the digital exchange 2, the communication control unit 4 determines whether or not to connect a sub-rate exchange call. First, the communication control unit 4 checks the use status of the subrate exchange trunk 7 in the subrate exchange trunk management means 6 and transmits a connection request for a normal call to which the subrate exchange is not applied if there is no available trunk to the base station. By directly connecting the line interfaces 3 and 8 for the extension and the outside, a normal call connection without passing through the subrate exchange trunk 7 is performed. If there is room in the trunk,
The communication control unit 4 compares the address stored in the address storage unit 5 with the destination address. Since the address stored in the address storage means 5 is the address of the game station having the subrate exchange trunk 7, there is an address which matches the address stored in the address storage means 5 and the destination address in the comparison stage. For example, it can be seen that a subrate exchange call can be connected to a game.

If there is no address corresponding to the destination address and the address stored in the address storage means 5, a connection request for a normal call to which sub-rate exchange is not applied is transmitted to the opposite station, and a connection request for an extension and an external line is transmitted. By directly connecting the line interfaces 3 and 8, a normal call is connected without passing through the subrate exchange trunk 7.
If an address coincident with the destination address exists in the address stored in the address storage means 5, a connection request for a call to which subrate exchange is applied is transmitted to the game. If the connection response to the connection request for the subrate exchange call indicates that the subrate exchange call can be connected, the communication control unit 4 connects the line interfaces 3 and 8 for the extension and the external line to the trunk 7 for subrate exchange, respectively. I do. As a result, the communication terminals 1a to 1d are connected to the terminal via the subrate exchange trunk 7, and the connection of the subrate exchange call is realized.

Data from the communication terminals 1a to 1d are compression-coded by the subrate exchange trunk 7 and multiplexed into time slots. The data multiplexed in the time slot is transmitted to the game terminal through the external line interface 8. The data transmitted from the opposite terminal is separated and decoded in the subrate exchange trunk 7 and then transmitted to each communication terminal 1a through the extension line interface 3.
To 1d. If the connection response to the connection request for the sub-rate exchange call indicates that the sub-rate exchange call cannot be connected due to the use status of the sub-rate exchange trunk 7 of the opposite station, etc., the line interface for the extension and the external line is used. By directly connecting 3,8,
A normal call connection without passing through the subrate exchange trunk 7 is performed.

Next, a case where a data transmission request is issued from a game station will be described. When a data transmission request is issued from the game terminal to the communication terminals 1a to 1d connected to the extension, the communication control unit 4 determines whether the transmission request is a request for a call to which sub-rate switching is applied or a normal transmission without sub-rate switching. Determine whether the request is for a call. Here, if the request is a request for a normal call to which subrate exchange is not applied, a connection response to the normal call is transmitted to the terminal, and the line interfaces 3 and 8 for internal and external lines are directly connected. , A normal call connection without passing through the subrate exchange trunk 7 is performed. If the data transmission request from the game indicates that a sub-rate exchange call is to be connected, the communication control unit 4 checks the availability of the sub-rate exchange trunk 7 in the sub-rate exchange trunk management means 6. .

If there is no free space in the subrate exchange trunk 7, a connection response indicating that connection of the subrate exchange call is impossible is transmitted to the opposite station, and the line interfaces 3 and 8 for internal and external lines are directly connected. Thus, a normal call connection without passing through the subrate exchange trunk 7 is performed. Further, when it is confirmed that the trunk is empty, the communication control unit 4 transmits a connection response indicating that the subrate exchange call can be connected to the terminal, and the line interface 3 for the extension.
And the external line interface 8 are connected to the subrate exchange trunk 7, respectively. As a result, the communication terminals 1a to 1d are connected to the game via the subrate exchange trunk 7. The data processing is the same as the data processing when a data transmission request is issued from the communication terminals 1a to 1d connected to the digital exchange 2.

Here, the address storage means 5 is a RAM (Ra
If the storage unit is a storage unit such as an ndom access memory) or a hard disk that can rewrite the storage information content, the storage information content can be dynamically updated. If the data transmission request generated from the game is a data transmission request by a communication method to which subrate exchange is applied, first, the communication control unit 4 compares the address stored in the address storage unit 5 with the source address. By doing so, it is checked whether the address is registered as an exchange having the subrate exchange trunk 7 or not. If there is no address that matches the source address and the address stored in the address storage unit 5, the source address that transmitted the data transmission request is newly added to the addresses stored in the address storage unit 5. By adding, the stored information content is updated.

[0016] Further, negotiation is performed with the game terminal as to whether or not to apply the sub-rate exchange using the connection request and the connection response. This is because the user adds information on the sub-rate exchange to the message used in the normal call setup procedure, transmits the message to the game, and the receiving side of the message has means for determining the additional information. / Non-application can be determined. For example, ISD
In N (Integrated Services Digital Network) communication, messages used in a normal call setup procedure include SETUP and ALER.
T, CONNECT, DISC and the like. The user can independently add a user information element to these messages. If information on sub-rate exchange is added to this user information element, it is easy to determine whether sub-rate exchange is applied or not.

FIGS. 3 and 4 are flowcharts showing a subrate exchange procedure. That is, it shows a sub-rate exchange procedure of a digital exchange having an address storage unit such as a non-volatile memory as the address storage unit whose information contents cannot be rewritten.

First, in the digital exchange according to the present invention, when a connection request is issued (S1), the communication control unit determines whether the own station is the calling side or the called side.
(S2) If it is determined that the own station is the calling side, the communication control unit checks the availability of the subrate exchange trunk in the subrate exchange trunk management means (S3), and the subrate exchange trunk is usable. Or not possible (S
Four). If a subrate exchange trunk is available,
The destination address is compared with the address stored in the address storage means (S5). In S5, the presence or absence of a matching address is confirmed (S6), and if an address matching the destination address is confirmed, a connection request for a call to which subrate exchange is applied is transmitted to the opposite terminal (S7). It is determined whether the connection response to the connection request is for a call to which subrate exchange is applied or for a normal call to which subrate exchange is not applied (S8). In S8, if it is determined that the response is a connection response to the call to which the subrate exchange is applied, the line interface for the extension and the line for the external line are respectively connected to the trunk for the subrate exchange, and the communication to which the subrate exchange is applied is started ( S1
7).

On the other hand, if it is determined in S8 that the connection request for the call to which the sub-rate exchange is applied is not accepted by the game and the connection response indicates that the connection to the sub-rate exchange call is not possible, the extension and the external line are not used. The normal communication without applying the sub-rate exchange is started by directly connecting the line interface for sub-rate exchange without passing through the trunk for sub-rate exchange (S11). In step S6, if a match between the transmission address and the address stored in the address storage unit is not found as a result of the comparison, it is considered that the game does not support the communication method to which the subrate exchange is applied, A normal call connection request to which the subrate exchange is not applied is transmitted to the opposite terminal (S9). When there is a connection response to this connection request (S10), normal communication without applying subrate exchange is started by directly connecting the line interfaces for internal and external lines without passing through the trunk for subrate exchange (S11). .

In S4, if it is determined that the trunk for sub-rate exchange is full and unusable, it is impossible to connect a sub-rate exchange call, so that a normal call to which the sub-rate exchange is not applied to the opposite station. Is transmitted (S9). If there is a connection response to this connection request (S1
0), by directly connecting the line interfaces for the internal and external lines without going through the trunk for sub-rate switching, normal communication without sub-rate switching is started.
(S11). If it is determined in S2 that the own station is the called side, it is determined whether the connection request from the opposite station is a connection request for a subrate exchange call or a connection request for a normal call to which subrate exchange is not applied. Do (S
12). If it is determined that the request is a connection request for a normal call, a connection response to the normal call is transmitted to the terminal in accordance with a normal call setup procedure (S13), and the line interfaces for the internal and external lines are sub-rate switched. Normal communication without subrate exchange is started by connecting directly without using a trunk for communication (S11).

When it is determined in S12 that the connection request from the opposite station is a connection request for a subrate exchange call, the communication control unit checks the availability of the subrate exchange trunk in the subrate exchange trunk management means. (S14), it is determined whether the trunk for subrate exchange is usable or impossible (S15). If the subrate exchange trunk is available, a connection response indicating that the subrate exchange call can be connected is transmitted to the opposite terminal (S16), and the internal and external line interfaces are respectively connected to the subrate exchange trunk. Then, communication to which subrate exchange is applied is started (S17).

In S15, if it is determined that the sub-rate exchange trunk is already in use and cannot be used, a connection response indicating that the sub-rate exchange call cannot be connected is transmitted to the terminal (step S15). S18) By connecting the line interfaces for the internal and external lines directly without using the trunk for sub-rate exchange, normal communication without sub-rate exchange is started (S17). S11 and S
In 17, when a line disconnection request is issued (S 19), the contents related to the usage status of the sub-rate exchange trunk stored in the sub-rate exchange trunk management means are updated, and the line disconnection is executed (S 20). Return.

FIGS. 5 and 6 are flowcharts showing a sub-rate exchange procedure of a digital exchange to which an address means rewritable, such as a RAM, is used. The difference from the flowcharts of FIGS. 3 and 4 is that when it is determined in S12 that the connection request from the game is a request for a subrate exchange call, first, the connection request transmission source address and the address are stored in the address storage means. A comparison is made with the address (S21), and it is determined whether or not the address is already registered as an exchange having a trunk for subrate exchange. In S21, the presence or absence of a matching address is confirmed (S22). If an address matching the transmission source address is confirmed, it is understood that the game has already been registered in the address storage means. Further, in S22, if the result of comparing the source address with the address stored in the address storage means does not find a match, the address of the game is not registered in the address storage means. The address is added to the address newly stored in the address storage means, and the content of the stored information is updated (S23). As described above, the processing procedure of S21, S22, and S23 is different from the flowcharts of FIGS. 3 and 4, and after the processing of S22 or S23 is completed, the process proceeds to S14 and subsequent processing procedures.

[0024]

Since the present invention is configured as described above, it has the following effects. (1) By providing a subrate exchange trunk having a compression encoding / decoding means in a digital exchange, line utilization efficiency is improved and communication costs are reduced. (2) Further, by providing the address storage means and the subrate exchange trunk management means, it is possible to confirm the presence or absence of the subrate exchange trunk of the opposite station and the availability of the subrate exchange trunk of the own station. Alternatively, a normal call can be automatically selected. Therefore, in the case where the exchange has both a switch having a trunk for subrate exchange and an exchange having no trunk for exchange, for example, when subrate exchange is applied to a public network, the trunk for subrate exchange can be used. Becomes (3) Further, by providing the address storage means with an address storage means capable of rewriting the content of the stored information, when a connection request for a subrate exchange call is generated from the game, it is stored in the address storage means at any time. The information content can be updated.

[Brief description of the drawings]

FIG. 1 is a configuration diagram for explaining an embodiment of a digital exchange according to the present invention.

FIG. 2 is a diagram for explaining a sub-rate exchange method according to the present invention.

FIG. 3 is a flowchart (part 1) showing a sub-rate exchange procedure according to the present invention.

FIG. 4 is a flowchart (part 2) illustrating a subrate exchange procedure according to the present invention.

FIG. 5 is a flowchart (part 1) showing another subrate exchange procedure of the present invention.

FIG. 6 is a flowchart (part 2) showing another subrate exchange procedure of the present invention.

FIG. 7 is a diagram showing a conventional digital exchange.

[Explanation of symbols]

Reference numerals 1a to 1d: communication terminals, 2: digital exchange, 3: line I / F (interface) for extension, 4: communication control unit, 5, address storage means, 6: trunk management means for subrate exchange, 7: subrate exchange Trunk, 7a ...
Compression encoding / decoding means, 7b ... MUX / DMUX, 8
... External line I / F (interface).

Claims (3)

(57) [Claims] 1. A converted into low-speed data by compression coding the data from a plurality of communication terminals connected multiplexes the time slots of one channel consisting of said predetermined number of bits,
A low-speed data is separated from a multiplexed time slot transmitted from a game station, and a sub-rate exchange trunk for decoding the compression-coded low-speed data is provided. A digital exchange for transmitting to a game terminal, separating and decoding the multiplexed time slot from the game in the sub-rate exchange trunk, and transmitting to a plurality of communication terminals.
At the exchange, a trunk management means for sub-rate exchange is installed.
The use of the sub-rate exchange trunk
Information to be stored, and the subrate exchange of the game when connected to the game.
By checking the usage status of the replacement trunk,
Rate-switching trunk is available or not available
Of the subrate exchange for both the local station and the remote station.
If rank is available, connect subrate switched calls
Negotiate with the game to establish a connection, and
One or both subrate exchange trunks
If not available, connect subrate switched call.
Negotiate with the game to make a normal call connection
A digital exchange characterized by making a normal connection through a connection . 2. A digital exchange according to claim 1, wherein
Te, the subrate provided an address storage means for storing the address of the opposite station having a replacement trunk, when the transmission request for data from the communication terminal occurs, whether the remote station transmission request is generated has a subrate exchange trunk To
Judgment is made by comparing the address in the address storage means with the address.If the game has a sub-rate exchange trunk, the data is compression-encoded by the sub-rate exchange trunk and multiplexed into time slots. A digital exchange characterized by transmitting data to a game station and transmitting data to the game without passing through the sub-rate exchange trunk when the game does not have a sub-rate exchange trunk. 3. The information storage device according to claim 2, wherein said address storage means stores information to be stored.
3. The digital exchange according to claim 2, wherein the content of the report is rewritable storage means .