JP3279590B2 - Private line exchange system for private branch 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 system for extending a digital private branch exchange (PBX), and more particularly to a remote private line exchange system for a private branch exchange which is useful for remote placement of terminals.

[0002]

2. Description of the Related Art In general, when communication facilities in a business premises are spread over a wide area of the premises, an L / T system card (line / trunk system card: a board on which a line / trunk circuit is mounted) is installed. A communication network is realized by distributing and connecting them to a central control unit of the PBX by a digital leased line and transmitting and receiving control signals and communication data to and from each other.

A conventional PBX of this type has a system configuration as shown in FIG. 8, and includes a central control unit 10 and a line / trunk unit 30 as main components. The central control unit 10 includes an MCPU 11, an LCPU 12,
The CM 13, the communication path unit 20, and the like are interconnected by a system bus 14. Here, the MCPU 11 is a unit that performs analysis, judgment, and instruction of signals transmitted / received to / from each control unit, and manages control of the entire system such as call processing, failure processing, and maintenance operation.

On the other hand, the LCPU 12 is
Is a unit for controlling and diagnosing the line / trunk unit 30 under the control of. CM13 is MCPU1
1 is a common memory between processors used for communication between the LCPU 12 and the system bus 14. Further, the communication path unit 20 is configured by a time switch (TSW).

On the other hand, the line / trunk section 30 has a plurality of L
/ T system card 32. The L / T card is a unit in which a plurality of line / trunk circuits are realized on one board. This L / T card has B
There are STI, DSTI, COTI, and the like. The BSTI controls the loop information monitoring of the standard telephone, counts and receives selection signals, and sends a calling signal. The DSTI controls transmission and reception of various signals to and from a terminal such as a digital telephone or a reception desk / relay desk. The COTI is a card for interface with an analog office line, and controls an incoming signal from the analog office exchange, a dial pulse / push button selection signal, and the like. These L / T cards 32 transmit and receive control signals to and from the LCPU 12 through the control highway 40.

On the other hand, the communication path section 20 and the L / T card 32 transmit and receive communication data through the communication path highway 50. Hereinafter, L directly accommodated in the PBX
The communication system between the / T system card 32, the LCPU 12, and the communication path unit 20 will be described in more detail. First, L / T system car
The control highway 40 is composed of a full-duplex serial path having a basic transmission rate of 2.048 Mbps with respect to communication between the CPU 32 and the LCPU 12. This control highway 4
A unit having an interface function for transmitting / receiving a signal to / from 0 is called an ILSI. M for ILSI
-There are ILSI12-1 and S-ILSI32-1,
One M-ILSI on one control highway, S-I
Up to 32 LSIs can be accommodated.

The M-ILSI 12-1 is mounted in the LCPU 12, and the S-ILSI 32-1 is an L / T system card 32.
(See FIG. 8). An address is assigned to each L / T card 32 (referred to as a card address), and the control highway 40 of the S-ILSI 32-1 is controlled.
Used as the address above. The transmission control method of the control highway 40 is divided into 32 time slots with a period of 4 ms, and a fixed length control packet having a header including a destination address field and the like is transmitted and received in each time slot.

The transmission direction of a control packet on the control highway 40 includes an upward direction and a downward direction. The down direction is a direction in which a control packet is transmitted from the M-ILSI to one or a plurality of S-ILSIs, and the control packet is transmitted using an arbitrary time slot.
When the M-ILSI transmits a control packet to one S-ILSI, the destination address field of the control packet is transmitted.
Field specifies the card address of the destination S-ILSI. Also, a specific type of L / T card 32
When a control packet is broadcasted to the destination, the card type (BSTI, DSTI, CO
TI, etc.). S-
The ILSI analyzes the destination address field and
Only the control packet sent to the SI is received.

On the other hand, the upward direction is one SI
This is the direction in which a control packet is transmitted from the LSI to the M-ILSI. The control packet is transmitted using a time slot corresponding to the card address of the source S-ILSI. The M-ILSI receives an unpredictable control packet between the time slot and the destination address field information. Thus, M-ILSI and a plurality of S-I
The LSIs face each other via the control highway 40 and can transmit and receive control packets. On the other hand, the L / T card 32 and the communication path unit 20 transmit and receive PCM-encoded communication data through the time division multiplexed communication path highway 50. The L / T card is the highway 50
The call data is transmitted and received using the time slot corresponding to the above card address.

As described above, the L / T system cards are distributed and installed, and these L / T system cards and the central control unit of the PBX are connected by a digital dedicated line to thereby control signals and communication data.
Data transmission / reception is possible, but in this type of conventional PBX, when transmitting / receiving a control signal and communication data on a digital dedicated line, the digital dedicated line is used without concentrating.
For this reason, the capacity of the digital leased line connected to the L / T card must be as large as the number of terminals connected to the L / T card, and the digital leased line cannot be used effectively.

[0011]

As described above, in the above-mentioned conventional PBX, a digital exclusive line is connected between a plurality of L / T cards and a central control unit of the PBX, which are dispersedly arranged in a business premises. Digital dedicated line for connecting to the L / T card is required for the number of terminals connected to the L / T card, so that the use efficiency of the digital dedicated line is reduced and communication is not performed. There was a problem that the cost also increased.

The present invention eliminates the above problems, improves the efficiency of use of a digital leased line, allows a large number of terminals to be accommodated by a small-capacity digital leased line, and realizes a remote private branch exchange that can realize a wide-area communication network at low cost. It is intended to provide a line accommodation system.

[0013]

In order to solve the above-mentioned problems, the present invention provides a private branch exchange main unit and a remote unit connected via a transmission line, and a terminal or a line is connected to the private branch exchange main unit. One line / trunk circuit, a first control highway for transmitting and receiving control signals between the first line / trunk circuit and the central control unit, and a first control highway for transmitting / receiving control signals between the first line / trunk circuit and the communication path unit. A first communication path highway for transmitting and receiving communication data between the first and second communication paths; and an interface unit for controlling transmission between the first control highway and the first communication path highway and the remote unit via the transmission path. A remote control unit for controlling transmission with the interface unit via the transmission line, a second line / trunk circuit for connecting a terminal or a line, A second control highway and a second communication path for connecting a transmission control unit and the second line / trunk circuit with substantially the same protocol as the first control highway and the first communication path highway, respectively. A private line exchange system for a private branch exchange provided with a highway, wherein the private branch exchange body sets line-concentration / non-concentration control data corresponding to each port of a second line / trunk circuit in the remote unit. Setting means for performing call connection control between the central control unit and a second line / trunk circuit in the remote unit based on the concentrating / non-concentrating control data set by the setting means. It further comprises a line concentrator / non-concentrator control means for controlling line concentrator / non-concentrator on the transmission line. Also, in the present invention, the line concentrator / non-concentrator control means may control the target terminal based on an incoming or outgoing call request for a terminal connected to each port of the second line / trunk circuit in the remote unit. Searching means for searching for the setting contents of the line concentrating / non-concentrating data corresponding to the above; acquiring a free time slot when the setting corresponding to the target terminal is non-concentrating; transmitting call data; Sends a disconnection instruction to a data transmission control means for transmitting call data using a time slot allocated to the target terminal and a line / trunk circuit accommodating the target terminal when there is no empty time slot. And a line block notifying means for sending a line block notification signal to the central control unit.

[0014]

According to the present invention, first, transmission / reception of a control signal is described.
An interface capable of transmitting and receiving signals to and from a control highway as an internal communication path used for transmitting and receiving control signals between a central control unit of a private branch exchange (PBX) main unit and a line / trunk circuit (L / T card). Section). In a remote unit at a remote location, P
A control highway having the same protocol as the control highway of the BX body is provided, and an L / T card is accommodated therein. Then, the interface connected to the control highway of the PBX body and the remote control highway are connected by a transmission line.

In the above configuration, the control signal transmitted by the central control unit to the control highway of the PBX main unit is received by the interface connected to the main control highway, and transmitted to the remote control highway through the transmission line. You. The remote L / T system card receives a control signal from the control highway and controls various communication terminals accommodated in the own card. Conversely, L / T at a remote location
The control signal transmitted from the system card to the remote control highway is transmitted to the control highway of the PBX main body through the transmission line and received by the central control unit.

As described above, according to the present invention, the L / T system card is provided between the central control unit of the PBX and the L / T system card at a remote location.
The control signal can be transmitted and received in the same manner as when the network is directly connected to the control highway of the PBX body and the communication path highway. For this reason, the central control unit can control the remote L / T card under the same conditions as the L / T card directly accommodated in the PBX. Conversely, the remote L / T card is PB
It can be controlled by the central control unit under the same conditions as those directly accommodated in X.

On the other hand, regarding transmission of speech data, PB
An interface capable of transmitting and receiving signals is connected to a communication path highway as an internal communication path between the communication path section of the central control unit of the X main unit and the L / T card. In a remote unit at a remote place, a communication path highway having the same protocol as the communication path highway of the PBX body is provided and connected to the L / T system card. Then, PBX
The interface connected to the communication path highway of the main body and the communication path highway at a remote place are connected by a transmission path.

In the above configuration, the downstream communication data from the communication path is transmitted to the remote L / T card through the communication path highway, the transmission path, and the remote communication path highway. In addition, upstream communication data from a remote L / T card is transmitted to the communication path section through the communication path highway, transmission path, and communication path highway in the remote area. In this way, communication data can be transmitted bidirectionally between the communication path section and the remote L / T card.

In the present invention, the PBX body and the L
Concentration / non-concentration control can also be performed on a transmission line (digital dedicated line) connecting the / T system card. In this case, the maintenance person selects a port on which the L / T card is to be condensed and a port on which the L / T card is not to be condensed, and sets the data from the maintenance terminal to the PBX body. The PBX body downloads the line concentration / non-line concentration data to the control unit (provided in the interface unit) of the digital leased line through the control highway. The control unit of the digital leased line which has received the line concentrating / non-concentrating data refers to the line concentrating / non-concentrating data corresponding to the outgoing or incoming port and controls the line concentrating / non-concentrating.

[0020]

[0021]

As described above, according to the present invention, the PBX main unit can accommodate the L / T system card of the remote unit under the same conditions as those accommodated in the PBX main unit. The communication equipment on the site where the main body is installed and the site separated from the public road can be accommodated in the PBX main body. On the premise of this storage form,
Further, when controlling the call connection between the PBX body and the remote unit,
On the transmission line, the line concentrator / non-concentrator is controlled corresponding to each port of the line / trunk circuit (L / T card) in the remote unit. For this reason, the line / trunk circuit (the number of ports) in the remote unit can be appropriately increased and the number of terminals accommodated therein can be varied dynamically depending on the setting of the line concentration / non-line concentration. As a result, one transmission line Can be used by more terminals, and the utilization efficiency of the transmission path can be improved.

[0023]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below in detail with reference to the accompanying drawings. FIG. 1 shows a schematic system configuration of a PBX to which the remote line accommodating method of the present invention is applied.

In FIG. 1, the PBX main body 1 comprises a central control unit 10 and a line / trunk unit 30.
Among these, the configuration of the central control unit 10 is the same as that of the conventional one shown in FIG. 8, but here only the communication path unit 20 is shown. Also, the line / trunk unit 30 has L / T
An L / T system card 32 directly accommodated in the PBX body 1 is connected to a control highway or a communication path highway as an internal communication path by being inserted therein.

On the other hand, an RU (remote unit) 70 is arranged at a remote location of the PBX main body 1. This RU7
0 is also the L / T shelf 7 similar to the L / T shelf 31
1 in which the same L as the L / T card 32 is included.
The / T system card 72 is inserted. Further, in the present invention, an RUI (remote unit interface) 60 is inserted in the L / T system shelf 31 in the PBX main body 1 separately from the L / T system card 32. Similarly, R
Even in the U70, the L / T shelf 71
An RUC (remote unit controller) 73 is inserted separately from the T-system card 72. And these R
The UI 60 and the RUC 73 are mutually connected by a transmission line 80.

The RUI 60 has a function as an interface for transmitting and receiving signals to and from the control highway and the communication path highway.
73. On the other hand, RUC73 is RU70
, A control highway and a communication path highway are sequentially provided, and a control signal and communication data are transmitted to and received from the RUI 60 through the transmission path 80. Further, as described above, the L / T system shelf 71 of the RU 70 has an L / T system card.
The L / T cards 72 each have a unique card address in a control highway (not shown) of the PBX main unit 1.

In the system of the present invention, the mounting of each card on each shelf is realized by the following structure. That is, in FIG. 1, a control highway and a communication path highway are provided on the L / T shelf 31 in each L / T.
There is a connector for connecting to the T-system card 32, and the L / T-system card 32 is usually inserted and mounted here.

The RUI 60 has connectors matching the above connectors, and the L / T shelf 31
, It is possible to connect to the control highway and the communication path highway. In addition, L of RU70
The / T system shelf 71 has the same connector as the L / T system shelf 31, and the L / T system card 72 similar to the L / T system card 32 housed in the PBX body 1 is directly inserted and mounted here. be able to.

Next, FIG. 2 shows the PBX of the present invention shown in FIG.
FIG. 3 is a diagram showing a more detailed system configuration of FIG. In FIG. 2, the RUI 60 has a CPU 60-
2, S-ILSI 60-1, SIO 60-3, multiplex switch 60-6, and the like. SI
The LSI 60-1 is connected to the control highway 40 and transmits and receives control packets. This S-ILSI60-1 is L
Unlike the S-ILSI32-1 on the / T system card 32,
All the control packets of the control highway 40 are received irrespective of the contents of the destination address field. Also,
Packets with different card addresses are sent to each card
It has a function of transmitting data using a time slot corresponding to the address.

SIO60-3 conforms to the X.10 specification recommended by CCITT. It supports layers 1 and 2 of the 25 protocol and transmits and receives signals to and from the communication path 60-5. The multiplexing switch 60-6 multiplexes the communication path 60-5 and the communication path highway 50 and connects to the transmission path 80. Transmission line 80
For this purpose, a super digital leased line or a private premises transmission line is used. In particular, when a super digital leased line is used, the following types of lines or a combination thereof are used. 384 k, 768 k, 1.5 M, 3 M, 6 M RU 70 is formed by connecting the RUC 73 and the L / T card 72 by the control highway 74 and the communication path highway 75. Here, the control highway 74 and the communication path highway 75 are equivalent to the control highway 40 and the communication path highway 50 in the PBX main body 1, respectively.

The RUC 73 is a CPU 7 for controlling the whole.
3-2, M-ILSI73-1, SIO73-3,
A multiplex switch 73-6 is provided. Among them, the M-ILSI 73-1 sends and receives control packets to and from the control highway 74 at a remote location. The SIO 73-3 is a unit similar to the SIO 60-3 in the RUI 60. The SIO 73-3 communicates with the communication path 73-5 connected to the multiplexing switch 73-6 with the CCITT Recommendation X.3. 25
Sends and receives signals according to the protocol.

The multiplexing switch 73-6 is connected to the communication path 73-
5 and the communication path highway 75 are multiplexed and connected to the transmission path 80. Therefore, SIO60-3 and SIO73-3
X. face each other. Signals are transmitted and received according to 25 protocols. The multiplexing switch 73-6 is connected to the transmission line 80.
Among them, 128 Kbps is fixedly allocated for data transmission on the control highways 40 and 74.

In the above configuration, the LC in the PBX body 1
A control signal transmission / reception system between the PU 12 and the L / T card 72 at a remote place will be described below. First, the control packet transmitted from the LCPU 12 to the control highway 40 is transmitted to a remote L / T
A case in which the system card 72 receives data will be described.

In this case, the control packet transmitted from the LCPU 12 on the control highway 40 is transmitted to the S-ILSI 6 in the RUI 60 regardless of the contents of the destination address field.
0-1. In the RUI 60, the CPU 60-2 transfers the control packet received by the S-ILSI 60-1 to the SIO 60-3 via the bus 60-4,
The SIO 60-3 sends this to the communication path 60-5. The control packet transmitted to the communication path 60-5 in this way is transmitted to the transmission path 80 via the multiplex switch 60-6.

The control packet on the transmission line 80 is transmitted to the communication line 73-5 via the multiplexing switch 73-6 of the RUC 73 in the RU 70, and received by the SIO 73-3. Also, in the RU 70, the CPU 72-2 is set to the SIO
The control packet received by M-ILSI 73-3
1 and the M-ILSI 73-1 sends the control packet to the control highway 74. As a result, PBX
Control highway 4 from M-ILSI 12-1 on the main unit 1 side
The control packet transmitted to the RU7 is transmitted to the remote RU7 as it is.
0 is sent to the control highway 74. Therefore, the L / T card 72 housed in the RU 70 is
The control packet from the LCPU 12 in the X main unit 1 can be received without any trouble.

Next, the control packet transmitted by the L / T card 72 in the RU 70 to the control highway 74 is transmitted to the LCPU
12 will be described. In this case, L
The control packet transmitted from the / T card 72 to the control highway 74 by the S-ILSI 72-1 is the M-ILSI 7
Received by 3-1. CPU73-2 is M-IL
The control packet received by the SI 73-1 is transferred to the SIO 73-3 through the bus 73-4, and the SIO 73-3 sends this to the communication path 73-5.

The control packet transmitted to the communication path 73-5 in this way passes through the multiplex switch 73-6 and is transmitted to the transmission path 8-5.
Sent to 0. The control packet on the transmission path 80 is transmitted to the communication path 6 in the RUI 60 via the multiplexing switch 60-6.
0-5 and received by SIO 60-3.
In the RUI 60, the CPU 60-2 transfers the control packet received by the SIO 60-3 to the S-ILSI 60-1.
Further, the S-ILSI 60-1 sends this packet to the control highway 40 using a time slot corresponding to the card address information on the card address field. As a result, the packet information sent from the L / T card 72-1 in the RU 70 to the control highway 74 is sent to the control highway 40 in the PBX main unit 1, whereby the CPU 12 in the PBX main unit 1 72 can be received.

As described above, according to the present invention, the LCPU 12 in the PBX main unit 1 controls the L / T system card 72 to
The T-system card 72 is directly controlled by each card on the highway 40.
Can be controlled under the same conditions as connecting to the location of the address. Further, the L / T system card 72 at the remote location is
The control from the LCPU 12 can be received under the same conditions as when the T-system card 72 is directly connected to the control highway 40 of the PBX body 1. At this time, transmission of the control packet on the transmission path 80 is described in X.264. The transmission error detection and retransmission functions of the 25 protocol make it possible to maintain a characteristic resistant to transmission errors due to noise and the like.

Further, according to the present invention, the communication data between the communication path section 20 in the PBX main body 1 and the L / T system card 72 at a remote location is provided.
Data transmission can also be performed. First, the communication data transmitted from the communication path section 20 to the L / T system card 72 is condensed by the multiplexing switch 60-6 in the RUI 60 on the communication path highway 50 and connected to the transmission path 80. After that, the packet is further transmitted to the same time slot on the communication path highway 75 on the communication path highway 75 by the multiplexing switch 73-6 in the RU 70. Conversely, the call data sent from the L / T card 72 to the call path section 20 is transmitted to the same time slot on the call path highway 50 on the call path highway 75.
As a result, the L / T card 72 is in the same state as directly connected to the communication path highway 50 in the PBX main unit 1, and the time slot on the communication path highway 50 corresponding to each card address is set. Can transmit and receive call data.

In this manner, the LBX card 72 at the remote location is the same as the PBX except that there is a certain transmission delay.
Under the control of the LCPU 12 under the same conditions as the L / T card 32 accommodated in the main unit 1, communication can be performed without any use using the time slot of the communication path highway 50 of the PBX main unit 1.

Next, the control of the line concentration / non-line concentration in the system of the present invention will be described with reference to FIGS.
In order to perform this control, in FIG. 3, a maintenance person uses a maintenance terminal or the like to transfer the data of the line collection / non-line collection to the LC in the PBX main body 1.
It is necessary to set in the PU 12 in advance.

The line congestion / non-concentration data set in the LCPU is then transmitted to the RUI 6 through the control highway 40.
0 download. After the download is completed, when an incoming call request is made to the terminal connected to the L / T card 72-1 accommodated in the RU 70, the incoming request signal is sent from the control highway 40 to the RUI 60, the transmission line 80, and the RUC 73. , The control highway 74 in the RU 70
And received by the L / T card 72-1 in the RU 70.

Next, in response to the line connection request from the LCPU 12, the RUI 60 transmits the call data using the already allocated time slot when the data of the terminal to which the incoming call is requested is out of line. Then, in the case of a line concentrator, an empty time slot is acquired and communication data is transmitted. At this time, if the time slot cannot be acquired, the RUI 60 sends a line block notification signal to the LCPU1.
L / T card 7 sent to RU 70 and housed in RU 70
A disconnect instruction signal is sent to 2-1. The LCPU 12 that has received the line block notification signal causes the calling terminal to listen to the BT. The above control is performed as shown in FIG.
And the control sequence shown in FIG.

On the other hand, when a call is transmitted from a terminal accommodated in the RU 70, the control is performed in accordance with the sequence shown in FIGS. 5 (a) and 5 (b). In this case, when the terminal trying to make a call picks up the receiver, the OFH of that terminal is raised.
(Off-hook) signal from the L / T card 72-1 to the control highway 74, RUC 73, transmission line 80, RUI 6
0, transmitted to the LCPU 12 through the control highway 40 (see FIG. 5A). The LCPU 12 receiving the OFH signal sends a line connection request to the RUI 60. The RUI 60 obtains an already allocated time slot to transmit and receive call data when the data of the terminal on the calling side is non-convergence according to the line connection request, and transmits / receives the call data when the data is concentrated. Get the time slot of
Sends and receives call data. At this time, if an empty time slot cannot be acquired, the RUI 60
A line block notification signal is sent to U12. L
When receiving the line block notification signal, the CPU 12 sends a disconnection instruction signal to the L / T card 72-
1 (see FIG. 5B).

As described above, according to the present invention, the utilization efficiency of the transmission line can be enhanced by controlling the line concentration / non-concentration on the transmission line 80, and the digital exclusive line connected to the L / T system card can be improved. Can be less than or equal to the number of terminals connected to the card.

By the way, the PBX main unit and the line / trunk circuit installed in the remote place are controlled by the same protocol as the control highway and the communication channel highway of the PBX main unit. In order to accommodate a high-speed digital transmission terminal such as a digital data terminal in a line / trunk circuit, the communication path highway needs to have a sufficient speed. On the other hand, as shown in FIG. 8, terminals accommodated in the line / trunk circuit include terminals (digital telephone terminals) that require a high transmission speed to perform high-speed digital transmission, as well as low-speed terminals. There are also voice terminals (standard telephone terminals) and low-speed data terminals that only require a transmission speed. Therefore, if the terminals having such different transmission speeds coexist, the transmission speed of the communication path highway between the PBX body and the remote line / trunk circuit in the above-described system of the present invention is changed to the high-speed transmission. If the terminal is set uniformly according to the terminal used for transmission, an excessive transmission rate will be provided to a terminal such as a voice terminal or a low-speed data terminal that can transmit at a relatively low speed.

A PBX having the system configuration shown in FIG. 6 has been devised as another embodiment of the present invention in order to solve such inconvenience. This system uses RUI6
0 and RU70, respectively, D / D60-7 and D / D60-7
/ D73-7. These D / D60-
7, D / D 73-7 is a corresponding multiplexing switch 60-.
6. A circuit which is connected to the multiplexing switches 73-6 and compresses / decompresses upstream or downstream communication data on the communication path highway forming the transmission path 80. Hereinafter, focusing on the operation of this circuit, the PBX in the system of FIG.
A method of transmitting communication data between the communication path section 20 in the main body and the L / T card 72 at a remote place will be described.

First, the downstream communication data on the communication path highway 50 transmitted from the communication path section 20 in the PBX body to the L / T system card 72 at a remote place is sent to the CPU 60-2 at the CPU 60-2. Whether compression is possible or not is determined based on the type of terminal connected to the L / T card 72. If it is determined that compression is to be performed, the CPU 60-2 causes the multiplexing switch 60-6 to connect the downlink communication data to the compression time slot of the D / D (digital signal compressor / decompressor) 60-7. . Here, D / D60-7 is shown in FIG.
As shown in (1), the input data to a specific time slot is compressed and output to the corresponding time slot, and similarly, the input data to the specific time slot is expanded and output to the corresponding time slot. I do. Thus, for example, D
The speech data input to the time slot 16 of / D60-7 is compressed from 64 Kbps to 32 Kbps, and similarly output to the time slot 8 together with the compressed speech data input from the time slot 17. The call data input to time slot 8 is 32 Kbps to 6
Expanded to 4Kbps, time slots 16, 17 respectively
Output to

The compressed downstream communication data is D
/ D60-7 is output to the output time slot corresponding to the input time slot.
, And connected to the transmission line 80. Thereafter, the compressed downstream communication data transmitted on the transmission path 80 is transmitted.
Is connected to the expansion time slot of the D / D 73-7 in the RU 70. D / D73-7 is also D / D60
-Has the same function as 7.

As a result, the downstream communication data expanded by the D / D 73-7 is output to the output time slot corresponding to the input time slot of the D / D 73-7, and is output by the multiplexing switch 73-6. Time slot with the channel highway 75 (same as on the channel highway 50)
Sent to

On the other hand, the CPU 72-2 determines whether or not the upstream communication data transmitted from the L / T card 72 to the communication path section 20 in the PBX main body on the communication path highway 75 can be compressed. If the data can be compressed, the data is transmitted on the transmission path 80 compressed by the D / D 73-7, and then transmitted to the same time slot on the communication path highway 50 expanded by the D / D 60-7 in the RUI 60. . Therefore,
Although the L / T card 72 is in the same state as directly connected to the communication path highway 50, the communication data can be compressed and the transmission path can be used efficiently, and each card address can be used. Communication data can be transmitted and received using the corresponding time slot on the communication path highway 50.

In each of the embodiments described above, the RUI is connected to the control highway of the PBX main body by the same interface as the L / T system card.
The amount of change in both the hardware and software of the BX body is small. In addition, even in a remote location, the same L / T system card as that accommodated in the PBX body is used for software and hardware in order to provide a highway of the same protocol as the control highway of the PBX body and the communication path highway. Can be used as is without modification.

As described above, when the present invention is applied to the PBX, there is very little change in the existing part, and the system can be expanded at low cost and in a short period of time. Further, according to the present invention, the line /
By applying compression / decompression processing to speech data on a transmission line connected to a trunk circuit according to the type of terminal, it is possible to contribute to further effective use of the transmission line and reduction of communication costs.

As described above, according to the present invention, a private branch exchange main unit and a remote unit located at a remote place are connected via a transmission line, and a line / trunk circuit in the remote unit and the line / trunk circuit are connected. Basically, the control highway and the communication path highway between terminals or lines accommodated in the trunk circuit are configured to be controlled by almost the same protocol as the control highway and the communication path highway in the private branch exchange main body, and the private branch exchange is used. At the time of call connection control between the main unit and the remote unit, control of the line concentrator / non-concentrator is performed on the transmission line corresponding to each port of the line / trunk circuit in the remote unit. With the above basic configuration, the extension /
Lines such as a part of office lines / dedicated lines are accommodated, and the same services as those directly accommodated in the private branch exchange main body can be provided for these remote lines. In addition, according to the present invention, at the time of the call connection control between the private branch exchange main unit and the remote unit, the line concentrator / non-concentrator control is performed on the transmission line corresponding to each port of the line / trunk circuit in the remote unit. ,
The number of lines / trunk circuits (the number of ports) in the remote unit can be increased as appropriate, and the number of terminals accommodated therein can be varied dynamically. As a result, one transmission line can be used by more terminals, and the transmission line can be used. Efficiency can be increased. As a result, when providing the services described above,
A large number of terminals can be accommodated by a small-capacity digital leased line, and a wide-area communication network can be realized at low cost while effectively using the digital leased line.

[Brief description of the drawings]

FIG. 1 is a system configuration diagram schematically showing a PBX according to one embodiment of the present invention.

FIG. 2 is a diagram showing a detailed configuration of the system shown in FIG. 1;

FIG. 3 is a system configuration diagram for explaining a line concentration / non-line concentration control method according to the present invention.

FIG. 4 is a control sequence diagram showing a specific example of line concentration / non-line concentration control for an incoming call to an extension telephone.

FIG. 5 is a control sequence diagram showing a specific example of line concentration / non-line concentration control for calling from an extension telephone.

FIG. 6 is a detailed system configuration diagram of a PBX according to another embodiment of the present invention.

FIG. 7 is an explanatory diagram of compression / expansion processing in a digital signal compression / expansion unit in the system shown in FIG. 6;

FIG. 8 is a system configuration diagram of this type of conventional PBX.

[Explanation of symbols]

Reference Signs List 10 Central control unit 11 MCPU (main control unit) 12 LCPU (local control unit) 12-1, 73-1 M-ILSI 13 CM (communication memory) 14 System bus 20 Communication path unit (TSW) 30 lines / Trunk (L / T) unit 31, 71 L / T system shelf 32, 72 L / T system card 32-1, 60-1, 72-1 S-ILSI 40, 74 Control highway 50, 75 Communication path highway 60 RUI (Remote Unit Interface) 60-2, 73-2 CPU 60-3, 73-3 SIO 60-4, 73-4 Bus 60-5, 73-5 Communication Path 60-6, 73- 6 Multiplexing switch 60-7, 73-7 Digital signal compressor / decompressor (D
/ D) 70 RU (remote unit controller) 73 RUC (remote unit controller) 80 transmission line

Continuation of the front page (56) References JP-A-62-208795 (JP, A) JP-A-1-261951 (JP, A) JP-A-2-277398 (JP, A) JP-A-63-136797 (JP) JP-A-1-297951 (JP, A) JP-A-57-25791 (JP, A) JP-A-4-213296 (JP, A) JP-A-1-265799 (JP, A) JP 56-147593 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) H04Q 3/58 101-3/60 H04Q 3/545 H04M 3/00

Claims (2)

(57) [Claims] 1. A private branch exchange main unit and a remote unit are connected via a transmission line, wherein the private branch exchange main unit has a first line / trunk circuit for connecting a terminal or a line, and the first line / trunk circuit. A first control highway for transmitting and receiving a control signal between the first line / trunk circuit and the central control unit; a first communication path highway for transmitting and receiving communication data between the first line / trunk circuit and the communication path unit; An interface unit for controlling transmission between the first control highway and the first communication path highway and the remote unit via a transmission line, wherein the remote unit includes the interface unit via the transmission line A second line / trunk circuit for connecting a terminal or a line, between the transmission control unit and the second line / trunk circuit. Are respectively connected to the first control highway and the first control highway.
A second control highway and a second communication path highway that are connected by substantially the same protocol as the communication path highway of the private branch exchange. Setting means for setting concentrating / non-concentrating control data corresponding to each port of the second line / trunk circuit; and the central control unit based on the concentrating / non-concentrating control data set by the setting means. A line concentrator / non-concentrator control means for controlling line concentrator / non-concentrator on the transmission line involved in call connection control with a second line / trunk circuit in the remote unit. Private line exchange system for private branch exchanges. 2. The line concentrator / non-concentrator control means, based on an incoming or outgoing call request for a terminal connected to each port of a second line / trunk circuit in the remote unit, to the target terminal A search unit for searching for the setting contents of the corresponding line-concentration / non-concentration data; and acquiring a vacant time slot when the setting corresponding to the target terminal is non-concentration and transmitting call data; A data transmission control means for transmitting call data using a time slot allocated to the target terminal, and, when there is no empty time slot, for transmitting a disconnection instruction to a line / trunk circuit accommodating the target terminal. 2. A remote line of a private branch exchange according to claim 1, further comprising line block notifying means for sending a line block notifying signal to said central control unit. Containment method.