JPH1042039A - Isdn subscriber line multiplexer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To efficiently conduct connection/opening processing of a communication line to/from a subscriber equipment connected to an ISDN having a representative telephone number. SOLUTION: The ISDN subscriber line multiplexer 27 is received/sent by a relay line exchange 13 connected to a communication network 7. A multiplexed signal 28 multiplexing a plurality of channels including transmission reception information with respect to the same subscriber 26 is demultiplexed in the unit of channels by a multiplexer/demultiplexer 33 and each information demultiplexed in the unit of channels is relayed to each communication channel of the subscriber equipment. In this case, te multiplexer has a signal link control section 36 making call control sequence processing of the common line signal system with respect to the relay line exchange 13, a call processing control section 37 for outputting identification information relating the transmission speed of the call connection information and the transmission reception information and ISDN interface circuits 34, 35 conducting the call control sequence processing with the subscriber equipment 26 based on the kind information and the call connection information.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ISDN subscriber line multiplexing apparatus for performing a switching process for a subscriber unit having a number of ISDN communication lines secured by one representative telephone number.

[0002]

2. Description of the Related Art A general public communication system is shown in FIG.
It is configured as shown in FIG. When information is exchanged between the telephones 1a and 1b as analog terminals distant from each other or between ISDN terminals 2a and 2b such as G4 facsimile, a connection request designating a call destination from the telephone 1a on the calling side is not required. The call is received by the telephone 1b via the internal exchange 3a, the toll switch 4a, the network 5, the toll switch 4b, and the local switch 3b. When the telephone 1b responds to the incoming connection request, a communication line is formed between the telephones 1a and 1b.

In addition, when the ISDN terminals 2a and 2b send a connection request from the originating ISDN terminal 2a via the TA (terminal adapter device) 6a, the receiving ISDN terminal 2b transmits the connection request via the TA 6b. And an ISDN line is formed between them.

Although the communication speed is reduced, it is also possible to connect an analog terminal such as a telephone to an ISDN terminal. In such a public communication system, communication between the local exchanges 3a and 3b and the toll exchanges 4a and 4b and between the toll exchanges 4a and 4b via the network 5 are performed individually to improve communication efficiency. The communication signal is digitized and further multiplexed. Therefore, each local exchange 3a, 3b separates the multiplexed signal input from the toll exchange 4a, 4b for each subscriber in addition to the original telephone exchange function, and multiplexes the communication signal from each subscriber. It has a demultiplexing / multiplexing function. If the subscriber uses a representative number, a plurality of lines are used with the same number.

[0005] In recent years, a service connection company which provides electronic mail management and connection to the Internet, etc., which is generally called a provider, has secured a large number of communication lines with one representative telephone number. Therefore, at the same time, a plurality of users can dial the representative number and form a communication line with the service connecting company to receive a desired service.

For such a special subscriber unit,
The signal is transmitted from the toll switch directly to the service connecting company without passing through the local switch. FIG. 10 is a schematic diagram showing an electronic mail service system using a general public communication network. A subscriber terminal 9 such as a personal computer is connected to a communication network 7 of a telephone company via a modem 8. An ISDN-compatible subscriber terminal 11 is connected via the TA 10.

A trunk exchange 13 is connected to the communication network 7 via a POI (interface demarcation point) 12. For example, a general local exchange 15 to which an individual subscriber terminal 14 is connected, and a service connection company 1 for electronic mail management and Internet connection are connected to the trunk exchange 13.
7 is connected to the subscriber line exchange 16.

[0009] The trunk exchange 13 separates the multiplexed signal received via the communication network 7, generates a multiplexed signal again for each local exchange 15, and sends it to the corresponding local exchange 15. At the same time, the trunk exchange 13 separates the received multiplexed signal, collects only communication signals designating the representative number of the service connection company 17, generates a multiplexed signal again, and sends it to the subscriber exchange 16. .

The subscriber line switch 16 includes, for example, a trunk 18, a time division multiplexing / demultiplexing circuit 19, a subscriber circuit 20,
It comprises an F receiver 21, a CPU 22, and the like. Then, the time division multiplexing / demultiplexing circuit 19 separates the multiplexed signal input via the trunk 18 and sends out the multiplexed signal to the subscriber line 23 connected to the service connection company 17 via the subscriber circuit 20. The subscriber line exchange 16 accommodates, for example, 3000 to 10000 lines that can be connected by the representative number.

The MF receiver 21 and the CPU 22 extract a telephone number included in each communication signal separated by the time division multiplexing / demultiplexing circuit 18 and set a corresponding communication path to the 30
Corresponding subscriber circuit 20 of 00 to 10000 lines
It has the function of switching and connecting to.

The multiplexing / demultiplexing function and the switching function of the local exchange 16 are almost the same as those of the general local exchange 15. Each communication signal input to the service connection company 17 via the subscriber line 23 is input via a modem 24 to an e-mail server 25 composed of a post computer or the like. The e-mail server 25 executes e-mail processing required by each communication signal input from the individual subscriber terminal 9.

When the e-mail server 25 of the service connection company 17 has an ISDN terminal function, a TA (terminal adapter device) is provided instead of the modem 24, and each communication signal input to the service connection company 17 is provided. Are respectively input to the e-mail server 25 via the TA.

[0013]

However, the subscriber line exchange 16 having the above-described structure has the following problems to be improved. In other words, each of the subscriber line exchanges 16 has one subscriber on the subscriber line side.
A plurality of service connection companies 17 having 00 to 500 lines
Is connected. The telephone number specified by each communication signal included in the multiplexed signal input from the trunk exchange 13 is only the representative number of one service connection company 17. With this one representative number, 100 to 500 lines can be connected to the electronic mail server 25 at the same time.

However, as described above, the local exchange 16 extracts the telephone number included in each of the separated communication signals and converts the corresponding communication signal into the corresponding telephone number, as in the general local exchange 15. Has an exchange function of allocating to a subscriber line corresponding to. However, as described above, since all communication signals input to the subscriber line exchange 16 need only be transferred to the predetermined service connection company 17, the exchange function is unnecessary.

Therefore, since the unnecessary switching function is incorporated, the subscriber line exchange 16 has a facility cost per one subscriber line which is substantially the same as that of a general local exchange 15 and the facility cost is reduced. Increase significantly.

In particular, when the e-mail server 25 of the service connection company 17 has an ISDN terminal function, the switching function incorporated in the subscriber line switch 16 is a switching function for a communication signal from a general analog subscriber terminal 9. In addition to the function, it is necessary to have an ISDN exchange function for exchanging communication signals from the ISDN-compatible subscriber terminal 11. As a result, the equipment cost of the local exchange 16 further increases.

The present invention has been made in view of such circumstances, and separates a multiplexed signal input from a trunk exchange into channel units, and uses a connection signal of a common channel signal system to separate each channel using a connection signal of a common channel signal system. By distributing the separated information directly to the communication channel of each subscriber device installed at the service connection company, the switching function can be eliminated while maintaining the high-speed transmission function of the ISDN line, and the equipment cost is greatly reduced. It is an object of the present invention to provide an ISDN subscriber line multiplexer capable of saving the cost and improving the connection processing efficiency between the trunk exchange and the subscriber unit.

[0018]

In order to solve the above-mentioned problems, an ISDN subscriber line multiplexer according to the present invention has the same subscriber units which are input and output to and from a trunk exchange connected to a communication network. A multiplexed signal obtained by multiplexing a plurality of channels including transmission / reception information is separated into channel units by a multiplexing / demultiplexing circuit, and each piece of information separated in channel units is relayed to each communication channel of the subscriber unit.

Further, the ISDN subscriber line multiplexer receives connection information corresponding to transmission / reception information from the trunk exchange, and relays the connection using the physical layer and signal link layer protocols of the hierarchical model in the common line signaling system. A signal link control unit for performing a call control sequence process of a common channel signaling system with the line exchange; and call connection information and transmission / reception information for the subscriber unit based on the call control sequence process executed by the signal link control unit. A call processing control unit that outputs type information related to the transmission speed of the multiplexing / demultiplexing circuit, and the type information and the call output from the call processing control unit for each separated channel of the multiplexing / demultiplexing circuit. Performs call control sequence processing of the ISDN interface method with the subscriber device based on the connection information to transmit / receive information to / from the subscriber device. And an ISDN interface circuit number.

In the thus constructed subscriber line multiplexer, the multiplexed signal input from the trunk exchange is separated into a plurality of channels by a multiplexing / demultiplexing circuit. The information of each channel demultiplexed by the multiplexing / demultiplexing circuit is relayed to each communication channel of the ISDN interface of the subscriber unit via the ISDN interface circuit allocated to the corresponding channel.

Therefore, information on each channel separated by the multiplexing / demultiplexing circuit is distributed to the same subscriber unit via a fixed ISDN interface circuit allocated to the corresponding channel in advance. That is, like a conventional subscriber line exchange, specified information such as a telephone number for specifying a subscriber unit included in a communication signal is extracted and a subscriber circuit (subscriber line) corresponding to the specified information is selected. Therefore, it is not necessary to allocate the corresponding communication signal to the selected subscriber circuit. Therefore,
The switching function can be eliminated from the ISDN subscriber line multiplexer of the present invention.

In the present invention, a call control sequence for connecting / disconnecting a communication line between a calling subscriber terminal and a destination subscriber device is defined by a signal link control unit and a call processing control unit. And each of the ISDN interface circuits.

Transmission and reception of signals between telephone stations (exchanges) in telephone exchange in a telephone company is performed by setting a set of information main body such as communication and data and connection information such as a transmission destination and a transmission source for each signal. The individual line signaling method for transmitting and receiving individually, and the information body such as call and data included in each signal are transmitted and received individually for each signal, but the connection information such as the destination and source included in each signal is collected together. There is a common line signaling system for transmitting and receiving via another common signal line. The connection information includes connection information between the source terminal and the destination terminal of the connection information between the stations.

In the common channel signaling system, a communication channel through which only information such as calls and data is transmitted and received and a common line link through which only connection information is transmitted and received are provided. , The efficiency of communication processing between stations can be improved.

In a communication system employing this common channel signaling system, call control sequence processing between stations is generally performed by a signal link control unit. Therefore, in the present invention, between the ISDN subscriber line multiplexer of the present invention and a trunk exchange, a signal link control unit receives a connection signal for transmission / reception information from the trunk exchange, and The call control sequence processing of the common channel signaling method is executed between the trunk exchange and the trunk exchange using the protocol of the physical layer and the signaling link layer of the hierarchical model in the scheme.

Further, based on the call control sequence processing in the signal link control section, call connection information for the subscriber unit and type information of transmission / reception information are provided for each ISDN interface provided corresponding to each channel of the multiplexing / demultiplexing circuit. Sent to the circuit.

Each of the ISDN interface circuits communicates with the subscriber unit based on the type information and the call connection information output from the call processing control unit for the information separated by the multiplexing / demultiplexing circuit. A control sequence process is performed to perform actual communication with the subscriber device.

Each piece of information separated by the multiplexing / demultiplexing circuit from the call processing control unit is classified by, for example, a transmission speed, and 28.8 kbit / S analog information corresponding to an analog line and ISD
N-line 64kbit / s synchronization information and ISDN line
38.4 kbit / s asynchronous information.

Therefore, each of the ISDN interface circuits transmits the received type information to the subscriber unit, so that the subscriber unit side uses the corresponding interface of the ISDN subscriber line multiplexer of the present invention at the corresponding interface.
Call control sequence processing can be performed with the interface circuit.

Therefore, even if the terminal on the transmitting side is an analog line terminal, the terminal on the basic interface ISDN
Even for compatible terminals, the primary group speed interface I
It may be an SDN-compatible terminal.

[0031]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram showing an electronic mail service system in which a subscriber line multiplexer according to the embodiment is incorporated. The same parts as those of the conventional e-mail service system shown in FIG. Therefore, the detailed description of the overlapping part is omitted.

In the electronic mail service system of this embodiment, a subscriber terminal 10 such as a personal computer is connected to a communication network 7 via a modem 9. In addition, the communication network 7 has an ISD
N corresponding subscriber terminals 11 are connected.

A trunk exchange 13 is connected to the communication network 7 via a POI (interface demarcation point) 12. A general local exchange 15 and an ISDN subscriber line multiplexer 27 to which a service connection company 26 for electronic mail management and Internet connection are connected are connected to the trunk exchange 13.

The trunk exchange 13 separates the multiplexed signal received via the communication network 7, generates a multiplexed signal again for each local exchange 15 and sends it to the corresponding local exchange 15. At the same time, the trunk exchange 13 separates the received multiplexed signal, collects only communication signals specifying the representative number of the service connection company 26, generates a multiplexed signal 28 again, and multiplexes the ISDN subscriber line. To the conversion device 27.

The multiplexed signal 28 is transmitted to the trunk exchange 13
And a multiplexed signal transmitted from the ISDN subscriber line multiplexer 27 to the trunk exchange 13.

Each of the multiplexed signals 32 is, for example, 8 Mbit / s
3 (a) or 3 (b), as shown in FIG. 3 (a) or 3 (b), the basic interface [2B + D] channel structure of the ISDN user / network interface
Information channels and the primary rate interface [2]
A total of 120 channels are multiplexed in combination with 23 information channels having a channel structure of [3B + D].

More specifically, for a trunk line of 8 Mbit / s, 1
In order to efficiently accommodate the next group rate interface (PRI), as shown in FIG. 3A, six channels from 1CH to 6CH are assigned to one hardware group (H
G), and eight lines of this hardware group (HG) are provided for five lines, and for each line, [23]
B + D], the primary group speed interface [23
[B + D] lines for two basic interfaces [2B
+ D] to accommodate 48 channels.

The two [23B + D] and [2B + D] 1
Two sets of book combinations (48CH) (48 × 2 = 96C)
H) and one set of [23B + D] and one set of [2B + D] are combined to implement a total of 120 channels.

As described above, in the multiplexed signal 28, [2
B + D] and [23B]
+ D] channels of the primary group speed number interface are incorporated without excess or deficiency.

Information from the analog line subscriber terminal 9 is also digitized and incorporated in any of the information channels for transmission and reception. Each of the exchanges 13 and 15 uses a common line signaling system to control connection of signals between the trunk exchanges 13, local exchanges 15 and exchanges (telephone offices) incorporated in the communication network 7. Central control unit (CC) 2
9, 30 are incorporated.

The central control units (CCs) 29 and 30 are connected to each other by a signal line 31, and a source exchange, a destination exchange, and a source of information transmitted and received between the exchanges via the signal line 31. It manages connection information of subscriber terminals, destination subscriber terminals, etc., and type information such as transmission speed and transmission protocol of transmission information.

Therefore, the multiplexed signal transmitted and received between the exchanges does not include the connection information or the type information. I
Trunk exchange 13 for outputting a multiplexed signal 28 containing no connection information or type information to the SDN subscriber line multiplexer 27
The common line signal 32 including the connection information and the type information on the multiplexed signal 28 output from the central control unit (CC) 29 incorporated in the ISDN is also input to the ISDN subscriber line multiplexer 27.

In the ISDN subscriber line multiplexer 27,
As shown in FIG. 1, one multiplexing / demultiplexing circuit 33, a plurality of basic ISDN interface circuits 34, a plurality of primary rate ISDN interface circuits 35, a signal link control unit 36, a call processing control unit 37, Is provided.

The multiplexing / demultiplexing circuit 33 is connected to the trunk exchange 13.
The digitalized information multiplexed on the multiplexed signal 28 input from the multiplexed signal 28 is separated into the original 120 channels, and the 120 channels are multiplexed into one multiplexed signal 28 and transmitted to the trunk exchange 13. I do.

Each basic ISDN interface circuit 3
4 and each primary group speed ISDN interface circuit 35
Are directly connected to the separated channels of the multiplexing / demultiplexing circuit 33. Each basic ISDN interface circuit 34 handles information of two channels among the separated channels, and each primary group speed ISDN interface circuit 35 handles information of 23 channels among the separated channels.

FIG. 4 shows each of the basic ISDN interface circuits 34 and each primary rate interface of each of the 120 channels of the multiplexed signal 28 shown in FIG. FIG. 14 is a diagram illustrating an assignment state of each circuit of the circuit 35.

As described above, 6 to 1CH to 6CH
8 hardware groups (HG) with channels
HG1 to HG8 form a total of 48 channels, and each channel has two [23B + D] lines and one basic interface [2B + D].
A primary group speed ISDN interface circuit 35 is assigned to each of two [23B + D] lines and one [2B + D].

The reference ISDN interface circuit 34 can be assigned to one [2B + D]. The primary group speed ISDN interface circuit 35 or the reference ISDN interface circuit 34 is allocated to the remaining 49CH to 120CH in the same manner.

The information of each channel output from each basic ISDN interface circuit 34 and each primary group speed ISDN interface circuit 35 is sent to the communication server 38 of the service connection company 26.

The signal link control unit 36 is connected to the trunk exchange 1
3 and receives the common line signal 32 output from the central control unit 29 incorporated therein, and uses the connection information included in the common line signal 32 to generate the physical layer and signal of the hierarchical model in the above-described common signal line system. Using a protocol of the link layer, a call control sequence process of the common signaling system is executed with the trunk exchange 13.

The call processing control unit 37 includes the signal link control unit 3
OS 6 based on the call control sequence process executed in
Using the protocol of the network layer in the I reference model, the call connection information for the connected subscriber unit and the type information on the transmission speed of each information included in the multiplexed signal 28 are transmitted to the ISDN interface circuits 34 and 35. .

As the type information on the transmission speed,
There is information to be notified to the communication server 38 of the service connection company 26 as the called-side subscriber device for the user-side line employed by the calling-side subscriber terminal shown in FIG.

As a user side line, an analog line such as a computer via a normal telephone or a modem and an ISDN
There are digital lines such as lines. Then, the communication server 38
As the type information on the transmission speed to be notified, the analog information with the transmission speed of 28.8 kbit / s at maximum and the ISDN line
64kbit / s synchronization information and 38.4kbit of ISDN line
/ s asynchronous information.

More specifically, as shown in FIG. 7, for example, the transmission rate of the information included in the ISUP (ISDN user) side user service information supplied by the connection signal 32 input from the central control unit 29 is The information is extracted and transmitted to each of the ISDN interface circuits 34 and 35 as type information.

Each ISDN interface circuit 34, 35
The type information and the call connection information output from the call processing control unit 37 with respect to the information of each channel accommodated in the own circuit separated by the multiplexing / demultiplexing circuit 33 between the communication server 38 of the service connection company 26 Performs call control sequence processing of the ISDN interface system to transmit / receive information to / from the communication server 38.

FIG. 5 shows each primary group speed interface (PR
I) is a format diagram of information transmitted from the circuit 35 to the communication server 38. Information on 23 channels separated from CH1 to CH23 and one type information 47 corresponding to the transmission rate received from the call processing control unit 37 are incorporated.

In the communication server 28, as shown in FIG. 2, an interface block 39 is provided for each of the ISDN interface circuits 34 and 35 in the ISDN subscriber line multiplexer 27. Each interface block 3
9 has an analog interface 40 corresponding to an information transmission speed of 28.8 kbit / s and an information transmission speed of 64 kbit / s.
interface 41 corresponding to ISDN / s, the transmission rate of information is, for example, 38.4 kbit / s, etc.
An SDN asynchronous interface 42 is incorporated.

Each of the corresponding interfaces 40, 41, 42 receives the type information 47 attached to the information 46 of each channel shown in FIG. 5 transmitted from each of the ISDN interface circuits 34, 35 in the ISDN subscriber line multiplexer 27. Judge,
When the speed type information 47 corresponding to itself is detected, a call control sequence process is performed with the corresponding ISDN interface circuits 34 and 35. Then, when a communication line is formed between the transmission source subscriber terminals 9 and 10, information is received via the communication line and transmitted to the LAN 44 via the router 43.

An e-mail server 45 is connected to the LAN 44.
Is connected. E-mail server 45 is LAN 44
It takes in the information sent above and performs a predetermined e-mail processing.

FIG. 8 shows an ISDN subscriber line multiplexer 27.
, Each subscriber terminal 9 connected to a communication server 38 of the service connection company 26 as a subscriber device and the communication network 7,
FIG. 10 is a diagram showing a call control sequence process executed between the call control sequence and the call control sequence.

The communication between the communication server 38 and the ISDN subscriber multiplexing device 27 is implemented by the ISDN interface system, and the ISDN subscriber multiplexing device 27 and the central control device 29 are used.
Is implemented by a common signal line system between the trunk exchange 13 in which the communication terminal 7 is incorporated and between the trunk exchange 13 and the originating exchange 48 of the communication network 7, and the originating exchange 48 and each subscriber terminal 9,
Between 10 and 10 is implemented by an ISDN interface system or a normal analog system. In addition, in the case of FIG.
It is assumed that the subscriber terminal 10 supports DN.

First, a setting (SETUP) message specifying the information type (transmission speed) is transmitted from the subscriber terminal 10 to the originating exchange 48. The originating exchange 48 transmits a call setup request (IAM) message to the trunk exchange 13. At the same time, a call setting process (CP) message is sent to the subscriber terminal 10.

The trunk exchange 13 sends the input call setup request (IAM) message to the ISDN subscriber line multiplexer 2.
7 to the signal link control unit 36. Call processing control unit 3
7 sends a setting (SETUP) message specifying an information type (transmission speed) to the communication server 38 via each of the ISDN interface circuits 34 and 35. At the same time, it sends an address information reception completion (ACM) message to the originating exchange 48 via the trunk exchange 13.

On the other hand, the interfaces 40 and 41.42 corresponding to the information type (transmission rate) of the communication server 38 return a call setting process (CP) message to the ISDN subscriber line multiplexer 27. Subsequently, the communication server 38
A calling (ALT) message is sent to the N-subscriber line multiplexer 27.

The ISDN subscriber line multiplexer 2 which has received the calling (ALT) message via the call processing control unit 37
The signaling link control unit 36 sends a call progress (CPG) message to the originating exchange 48 via the trunk exchange 13. The originating exchange 48 sends a calling (ALT) message to the originating subscriber terminal 10.

When the communication server 38 makes a connection response (CONN) to the ISDN subscriber line multiplexer 27, the ISDN subscriber line multiplexer 27 switches the trunk line switch 1
An on-hook response (ANM) message is sent to the originating exchange 48 via the third party. The originating exchange 48 connects (CONN) the line with the subscriber terminal 10 of the origin. As a result, a communication line is formed between the subscriber terminal 10 and the communication server 38, and the subscriber terminal 10 and the communication server 3
8, information is exchanged.

When the predetermined information exchange is completed, the subscriber terminal 10
Outputs a disconnection request (DISC), the originating exchange 4
8 sends a release request (REL) message to the trunk exchange 13. The trunk exchange 13 sends a release request (REL) message to the ISDN subscriber line multiplexer 27 and completes the recovery (RLC) to the originating exchange 48.
Send a message.

The originating exchange 48 sends a release request (REL) message to the subscriber terminal 10. Subscriber terminal 10
Sends a recovery complete (RLC) message to the originating exchange 48.

On the other hand, the ISDN subscriber line multiplexer 27 outputs a disconnection request (DISC) to the communication server 38 and sends a recovery completion (RLC) message to the trunk exchange 13.

Further, the communication server 38 sends a release request (REL) message to the ISDN subscriber line multiplexer 27, and the ISDN subscriber line multiplexer 27 completes recovery (RLC) to the communication server 38. Send a message.

In the ISDN subscriber line multiplexer 27 configured as described above, the multiplexed signal 28 input from the trunk exchange 13 is transmitted to the multiplexing / demultiplexing circuit 33 by, for example, 12
It is separated into a plurality of channels such as 0. The information of each channel demultiplexed by the multiplexing / demultiplexing circuit 33 is transmitted via the basic ISDN interface circuit 34 and the primary rate interface circuit 35 assigned to the corresponding channel to the communication server 38 of the service connection company 26. Each interface 40 corresponding to the transmission speed of information to be transmitted / received,
It is relayed to 41 and 42, respectively.

Therefore, the information of each channel separated by the multiplexing / demultiplexing circuit 33 is a fixed ISDN interface circuit 34.35 pre-assigned to the corresponding channel.
Via the communication server 38 of the same service connection company 26
Delivered to That is, like a conventional subscriber line exchange, specified information such as a telephone number for specifying a subscriber unit included in a communication signal is extracted, and a subscriber circuit (subscriber line) corresponding to the specified information is selected. It is not necessary to allocate the corresponding communication signal to the selected subscriber circuit. Therefore, the IS of the present invention
An expensive switching function corresponding to ISDN can be eliminated from the DN line multiplexer 27.

Further, in the ISDN subscriber line multiplexer 27, a communication line is connected / released between the subscriber terminals 9 and 10 of the transmission source and the communication server 38 which is the subscriber device of the transmission destination. The call control sequence process is executed by the signal link control unit 36, the call processing control unit 37, and the ISDN interface circuits 34 and 35 in a shared manner. Further, in the signal link control unit 36, the trunk exchange 1
3 is executed using a common signal line system instead of the individual signal line system.

Accordingly, the communication processing efficiency with the trunk exchange 13 can be improved. As a result, the processing speed of the entire e-mail service system using the ISDN subscriber line multiplexer 27 can be improved.

Further, the ISDN subscriber line multiplexer 27
From the call processing control unit 37 to the respective ISDN interface circuits 34 and 35, three types of type information corresponding to the transmission speed of each information separated by the multiplexing / demultiplexing circuit 33 are transmitted. Each ISDN interface circuit 34.35 transmits the received type information to the communication server 38.

As a result, on the communication server 38 side, call control sequence processing can be performed between the corresponding interfaces 40, 41 and 42 and the corresponding ISDN interface circuits 34 and 35 of the ISDN subscriber line multiplexer 27.

Therefore, the subscriber terminal on the transmitting side may be the subscriber terminal 9 of the analog line, the ISDN-compatible terminal 10 of the basic interface, or the ISDN-compatible terminal of the primary group speed interface. Good. That is, it is possible to support the subscriber terminals 9 and 10 having various transmission functions, and to greatly expand the applicable range.

[0078]

As described above, in the ISDN subscriber line multiplexer according to the present invention, the multiplexed signal input from the trunk exchange is separated into channels and the connection signal of the common line signal system is used. Each of the information separated into each channel is directly distributed to the communication channel of each subscriber device.

Therefore, the conventional switching function can be eliminated while maintaining the high-speed transmission function of the ISDN line, the equipment cost can be greatly reduced, and the line connection processing efficiency between the trunk exchange and the subscriber unit can be reduced. Can be improved. In addition, it can correspond to a subscriber terminal on the transmitting side having various transmission functions including an analog line and a digital line, and the application range can be greatly expanded.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing an electronic mail service system incorporating an ISDN subscriber line multiplexer according to an embodiment of the present invention.

FIG. 2 is a block diagram showing a schematic configuration of a communication server of a service connection company of the electronic mail service system;

FIG. 3 is a diagram showing a channel configuration of a multiplexed signal of the apparatus of the embodiment.

FIG. 4 is a diagram showing an assignment state of each channel of the multiplexing / demultiplexing circuit of the embodiment device to each ISDN interface circuit;

FIG. 5 is a format chart showing information and type information transmitted from each ISDN interface circuit of the apparatus of the embodiment to the communication server;

FIG. 6 is a view showing the relationship between the type of line on the user side of the apparatus of the embodiment and the type information;

FIG. 7 is a diagram showing a relationship between user service information and type information included in a common line signal of the apparatus of the embodiment.

FIG. 8 is a control sequence processing diagram showing an operation of disconnecting a communication line of the apparatus of the embodiment.

FIG. 9 is a schematic configuration diagram of a general public communication system.

FIG. 10 is a schematic diagram showing an electronic mail service system in which a conventional subscriber line switch is incorporated.

[Explanation of symbols]

7 communication network, 9, 10 subscriber terminal, 13 trunk switch, 15 local exchange, 26 service connection company (subscriber equipment), 27 ISDN subscriber line multiplexer, 28
Multiplexed signal, 29, 30 Central control unit, 32 Common line signal, 33 Multiplexing / demultiplexing circuit, 34 Basic ISDN interface circuit, 35 Primary rate interface circuit, 36 Signal link control unit, 37 Call processing control unit, 3
8 Communication server, 45 Email server

Claims (1)

[Claims] A trunk exchange (1) connected to a communication network (7).
A multiplexed signal (28) obtained by multiplexing a plurality of channels including input / output information to / from the same subscriber unit (26) input / output to / from 3) is separated into channel units by a multiplexing / demultiplexing circuit (33). An ISDN subscriber line multiplexer (27) for relaying each piece of information separated into each channel to each communication channel of the subscriber unit, receiving connection information for the transmission / reception information from the trunk line switch. A signal link control unit (36) for performing a common channel signaling call control sequence process with the trunk exchange using a protocol of a physical layer and a signaling link layer of a hierarchical model in a common signaling system; A call processing control unit (37) that outputs call connection information for the subscriber unit and type information related to a transmission speed of the transmission / reception information, based on a call control sequence process performed by the link control unit; ISDN is provided for each channel of the multiplexing / separating circuit, and is provided between the subscriber unit and the ISDN based on the type information and the call connection information output from the call processing control unit for the separated information. A plurality of ISDN interface circuits for performing a call control sequence process of an interface system to transmit and receive information to and from the subscriber unit;
An ISDN subscriber line multiplexer comprising: