JPH06178343A - Remote line storing system for private branch exchange - Google Patents

Abstract

PURPOSE:To maintain the high utilizing efficiency of a private line by controlling the connection processing of a terminating call by a digital private line channel control table. CONSTITUTION:When a terminating call is incoming to the number of a multi- appearance group, a channel for calling which is a free state on a digital private line is secured for the terminating call. The channel is corresponded to the multi-appearance group number and is stored in a digital private line channel control table 60-7. Subsequently, when a terminal within the group responds to the terminating call, a central control part 10 connects the already secured calling channel with a response terminal 76, while referring to the data within the table 60-7, and starts the transmission of calling data. Therefore, also for the terminating call to a group terminal 76, the connection processing can be coped with by using only a channel for calling on the digital private line.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a remote line accommodation system of a private branch exchange for accommodating terminals, office lines, etc. in a remote place,
In particular, it relates to improvement of channel control for incoming calls associated with the multi-appearance function.

[0002]

2. Description of the Related Art In general, when communication facilities on a premises are spread over a wide area of the premises, a line / trunk card (a board on which a line / trunk circuit is mounted: hereinafter referred to as an L / T card) To establish a communication network by connecting the central control units of a private branch exchange (PBX) with a digital leased line and transmitting and receiving control signals and call data to and from each other.

FIG. 4 shows the basic structure of a conventional PBX of this type. The central control unit 10 and the line / trunk units 30 dispersedly arranged at the remote location are controlled by a control highway 40 and a communication path highway 50. Connected via.
Of these, the central control unit 10 includes the MCPU 11 and the LCPU.
12, the CM 13, the speech path unit 20 and the like are connected to each other by a system bus 14. Here, the MCPU 11 is a unit that analyzes, determines, and gives an instruction to a signal transmitted / received to / from each control unit to be described later, and controls the entire system such as call processing, failure processing, and maintenance operation.

On the other hand, the LCPU 12 is the MCPU 11
Is a unit for controlling the line / trunk section 30 and diagnosing under the control of. Further, the CM 13 is an inter-processor common memory used for communication between the MCPU 11 and the LCPU 12 performed via the system bus 14. Further, the call path unit 20 is a unit that handles call data exchange processing, and is configured by a time switch (TSW).

On the other hand, the P having the central control unit 10 having such a configuration
A plurality of L / T cards 32 are provided in the line / trunk section 30 at a remote location of the BX. The L / T card 32 is a unit in which a plurality of line / trunk circuits are mounted on a single board, and includes BSTI, DSTI,
There are types such as COTI. Among these, BSTI is for monitoring loop information of the standard telephone terminal 33, counting and receiving selection signals,
Controls sending of call signals. Also, DST
I controls transmission / reception of various signals to / from a digital telephone terminal 34 (which may be a multi-appearance group terminal in some cases) and a terminal such as a reception board / relay board. Further, the COTI is an interface card for the analog office line 35, and controls the incoming signal from the analog office exchange and sends out dial pulse / push button selection signals. These L / T cards 32
Transmits and receives control signals to and from the LCPU 12 in the central control unit 10 through the control highway 40.

On the other hand, the call path unit 20 and the L / T system card 32 send and receive call data through the call path highway 50. Here, L / directly collected in PBX
An outline of a communication system between the T-system card 32, the LCPU 12 and the speech path unit 20 will be described. First, regarding the transmission / reception of the control packet between the L / T card 32 and the LCPU 12, the control highway 40 that controls the transmission is configured by a full-duplex serial path having a basic transmission rate of 2.048 Mbps. A unit having an interface function for transmitting / receiving a signal to / from the control highway 40 is ILS.
I. ILSI includes M- ILSI12-1 and S-
There is an ILSI32-1, and one control highway has M
-Up to 1 ILSI and 32 S- ILSIs can be accommodated. The M-ILSI12-1 is mounted in the LCPU12, and the S-ILSI32-1 is mounted in the L / T card 32 (see FIG. 4). Individual L / T card 3
An address is assigned to 2 (called a card address), and is used as an address on the control highway 40 of the S-ILSI 32-1.

The transmission control method of the control highway 40 is 4 ms.
Each time slot is divided into 32 time slots, 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 the control packet on the control highway 40 includes an up direction and a down direction. The downlink 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,
In the destination address field of the control packet, the card address of the destination S-ILSI is specified. Further, when the control packet is sent to the L / T type card 32 of a specific type by broadcast, an identifier corresponding to the card type (BSTI, DSTI, COTI, etc.) is set in the destination address field. The S-ILSI analyzes the destination address field and receives only the control packet sent to its own ILSI.

On the other hand, one S-I is used in the upstream direction.
The control packet is transmitted from the LSI to the M-ILSI, and the control packet is transmitted using the time slot corresponding to the card address of the transmission source S-ILSI. The M-ILSI receives an unpredicted control packet between the time slot and the destination address field information. In this way, the M-ILSI and a plurality of S-Is are
The LSIs can face each other via the control highway 40 and can send 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 system card 32 transmits / receives call data using a time slot corresponding to the card address on the call path highway 50.

In this type of conventional PBX, the digital dedicated line (control highway 40 and communication path highway 50) connecting the L / T card 32 and the central control unit 10 is used without being concentrated. Therefore, for example, when allocating a channel for a call on a digital leased line to an incoming call, first secure the channel for the call corresponding to each terminal of the destination of the incoming call, and then allocate the channel. The call processing is performed in which the channel is stored and the channel is connected in response to the response from the destination terminal. With this call processing method, the digital leased line cannot be effectively used, and this tendency is particularly noticeable in the processing of incoming calls related to the multi-appearance function.

As is well known, the multi-appearance function divides a digital telephone terminal into groups, assigns one group number to a button of a terminal belonging to this group, and receives a call to this group number. The call is a function that can be answered from any terminal in the group. Regarding the multi-appearance function, for example, in the PBX shown in FIG. 4, the digital telephone terminal 3 accommodated in the DSTI in the line / trunk section 30 is used.
4 is divided into groups with the same number for each
It forms a multi-appearance group terminal. According to the above-mentioned conventional call processing relating to an incoming call to the multi-appearance group terminal 34, first, a vacant communication channel of the communication path highway on the digital leased line is secured for each of all the terminals 34 belonging to the group, This channel is stored for subsequent call connection control to the answering terminal.

When a terminal in the group responds, the stored data is referred to, and the channel on the digital leased line which is reserved and stored corresponding to the response terminal is transmitted to the response terminal in order to transmit the call data. Connected,
After that, it becomes possible to shift to a call. At this time, the channels on the digital leased line which are reserved and stored corresponding to the non-responsive terminals in the group are simply released as they are.

According to the conventional PBX that performs this call processing,
When receiving a call to a number of a multi-appearance group, if the channels of all terminals belonging to the group cannot be secured, the channel of the digital leased line to be connected when any terminal in the group responds cannot be guaranteed.
The call will be immediately disconnected. On the other hand, if the call channels for all the terminals in the group are safely secured, the unused call channels tend to run short, and during that time, other incoming calls often cannot be accepted, resulting in efficient use of the line. Will be lowered. In consideration of this point, in the conventional PBX, in order to ensure the processing of the incoming call to the multi-appearance group, it is common to prepare more channels than the channels actually used in advance. It was extremely uneconomical in construction.

[0013]

As described above, in the above-mentioned conventional PBX, the channel on the digital leased line is secured corresponding to each terminal of the callee in the incoming call connection processing, and therefore the utilization efficiency of the channel is improved. It was low. In particular, in the process of connecting an incoming call to a terminal in a multi-appearance group, although only one channel is eventually used to connect to a certain answering terminal in the group, until the connection is established, It is necessary to secure communication channels for all the terminals belonging to the group, and it is necessary to increase the number of channels in order to ensure channel reservation at that time, which results in an uneconomical system configuration. There was a problem of not getting. The present invention eliminates the above-mentioned problems, maintains a high usage efficiency of a digital leased line even in connection processing of an incoming call related to a multi-appearance function, and at the same time contributes to an economical system construction. The purpose is to provide.

[0014]

SUMMARY OF THE INVENTION According to the present invention, an interface card mounted to accommodate terminals in a private branch exchange main body and a remote unit is connected by a digital leased line capable of transmitting control data and call data. The remote unit while selectively securing an empty channel among the channels on the digital leased line set to a number smaller than the number of remote terminals accommodated in an interface card in the remote unit in response to a call. In a remote line accommodation system of a private branch exchange for transmitting call data between local terminals, channel management data storage means for storing channel management data corresponding to the usage status of each channel on the digital leased line, and a plurality of said terminals It is divided into multi-appearance groups that can be identified by the same number for each Incoming call detecting means for detecting an incoming call related to the multi-appearance function, which can be answered from any terminal in the loop, and a channel for securing one free channel on the digital leased line for a call received to the number of the multi-appearance group. There is a securement means, a storage control means for storing the channel secured by the channel securement means in the channel management data storage means in association with the number of the multi-appearance group, and a storage control means for storing the incoming call in the multi-appearance group. When the terminal responds, the connection control means for connecting the responding terminal to the already secured channel is provided while referring to the management data in the channel management data storage means.

[0015]

According to the present invention, when an incoming call arrives at a number of a multi-appearance group, one call channel in an idle state on the digital leased line is secured for the incoming call.
The channel is stored in the channel management data storage means in association with the multi-appearance group number.
Thereafter, when a terminal in the multi-appearance group responds to the incoming call, the already secured call channel is connected to the answering terminal by referring to the data stored in the channel management data storage means, and the call data is sent. To start transmission.

According to such call processing, even for an incoming call to the multi-appearance group terminal, the connection processing can be dealt with by using only one call channel on the digital leased line from beginning to end. For this reason, in the present invention, the call channel in the unused state is less than the number of all terminals belonging to the multi-appearance group as in the conventional case, and the incoming call to the number of the group is disconnected, and Securing communication channels for all terminals does not impede the connection processing of other incoming calls, and the line usage efficiency can be significantly improved. Further, with the improvement of the line use efficiency, even in a system accommodating a large number of multi-appearance group terminals, it is not necessary to unnecessarily increase the number of channels, and it is possible to construct an economical system.

[0017]

Embodiments of the present invention will now be described in detail with reference to the accompanying drawings. FIG. 1 is a schematic system configuration diagram of a PBX to which the remote line accommodation system of the present invention is applied.
In FIG. 1, the entire system is configured by connecting a RU 70 to a remote place of the PBX main body 1 via a transmission line 80. PBX
The main body 1 includes a central control unit 10 and a line / trunk unit 30. Here, the configuration of the central control unit 10 is similar to that of FIG.
1, LCPU12, CM13 are provided. Further, the line / trunk section 30 has an L / T system shelf 31, and an L / T system card 32 directly accommodated in the PBX main body 1.
Is inserted into the control highway or the communication path highway as an internal communication path. In addition, an RUI (remote unit interface) 60 is also inserted in the L / T system shelf 31.

On the other hand, the RU 70 arranged at a remote location of the PBX main body 1 also has an L / T system shelf 71 similar to the L / T system shelf 31. This L / T system shelf 7
An L / T card 72 similar to the L / T card 32 is inserted into the card 1. In addition, a RUC (remote unit controller) 73 is inserted in the L / T system shelf 71 in the RU 70. In the system of the present invention, the RUI 60 and the RUC 73 are connected to each other by the transmission line 80 in the configuration in which the remote terminal is accommodated in the PBX main body 1. Here, the RUI 60 has a function as an interface for transmitting and receiving a signal to and from the control highway and the communication path highway in the PBX main body 1.
The signal is transmitted / received to / from the RUC 73 through the transmission line 80. On the other hand, the RUC 73 sequentially provides the control highway and the communication path highway in the RU 70, and
Control signals and call data are transmitted to and received from the RUI 60 through the transmission path 80.

As described above, the L / T card 72 is inserted into the L / T shelf 71 of the RU 70. These L / T cards 72 are unique to the control highway (not shown) of the PBX main body 1. Card address of each. In the system of the present invention, mounting of each corresponding card on each shelf is realized by the following structure. That is, in FIG. 1, the L / T system shelf 31 has a connector for connecting the control highway and the communication path highway in the PBX main body 1 to each L / T system card 32. The card 32 is inserted and mounted. The RUI 60 has a connector that matches the above-mentioned connector, and the L / T shelf 31
Can be connected to the control highway and the communication path highway. Also, L of RU70
The / T system shelf 71 has a connector similar to that of the L / T system shelf 31, and an L / T system card 72 similar to the L / T system card 32 accommodated in the PBX main body 1 can be directly inserted and mounted therein. is there.

FIG. 2 is a detailed system configuration diagram of the PBX shown in FIG. In FIG. 2, the PBX main body 1
The RUI 60 installed inside is a CPU that controls the whole
60-2, S- ILSI60-1, SIO60-
3, a multiplexing switch 60-6, a digital leased line channel management table 60-7 and the like. Of these, the S-ILSI 60-1 is connected to the control highway 40 to send and receive control packets. This S-ILSI6
Unlike the S-ILSI 32-1 on the L / T card 32 in the line / trunk section 30, the 0-1 receives all control packets of the control highway 40 regardless of the contents of the destination address field. It also has the function of sending packets with different card addresses using the time slots corresponding to each card address.

SIO60-3 is an X.60 recommended by CCITT. It supports Layers 1 and 2 of the 25 protocol and sends 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 them to the transmission path 80. As the transmission line 80, for example, a super digital leased line is used, and 384
A line having a transmission rate (bps) of k, 768k, 1.5M, 3M, 6M or the like or a combination thereof is used. The digital leased line channel management table 60-7 manages various states of each channel on the transmission line 80, which are unused, reserved, and in use, in association with terminal addresses or numbers unique to the multi-appearance group. It's a table. FIG. 3 shows an example of the storage form of the management data in the digital leased line channel management table 60-7. The writing and reading of each management data with respect to the digital leased line channel management table 60-7 is performed by the CPU 60-2.
Done by.

On the other hand, the RU 70 arranged at a remote place of the PBX main body 1 is constituted by connecting the RUC 73 and the L / T system card 72 by a control highway 74 and a communication path highway 75. Here, the control highway 74 and the communication path highway 75 are respectively equivalent to the control highway 40 and the communication path highway 50 in the PBX main body 1. The RUC 73 controls the whole CPU 73.2
Besides, it is composed of an M-ILSI 73-1, a SIO 73-3, and a multiplexing switch 73-6.

Among them, the M-ILSI 73-1 transmits / receives a control packet to / from the control highway 74 in a remote place. Further, the SIO 73-3 is a unit similar to the SIO 60-3 in the RUI 60, and for the communication path 73-5 connected to the multiplexing switch 73-6,
CCITT Recommendation X. Transmission and reception of signals based on the 25 protocol. The multiplexing switch 73-6 is a communication path 73-5.
Also, the communication path highway 75 is multiplexed and connected to the transmission path 80. Therefore, the SIO 60-3 and the SIO 73-3 face each other in the X. Signals can be transmitted and received by the 25 protocol. The multiplexing switch 73-6 fixedly allocates 128 Kbps of the transmission line 80 for data transmission between the control highways 40 and 74.

In the above structure, the LC in the PBX main body 1
A method of transmitting / receiving a control signal between the PU 12 and the L / T card 72 at a remote place will be described below. First, the control packet sent from the LCPU 12 to the control highway 40 is transmitted to the L /
A case where the T card 72 receives the data will be described. In this case, the control packet on the control highway 40 sent by the LCPU 12 is received by the S-ILSI 60-1 in the RUI 60 regardless of the contents of the destination address field. In the RUI 60, the CPU 60-2 is S-
The control packet received by the ILSI 60-1 is transferred to the bus 60-
4 to the SIO 60-3, and the SIO 60-3 sends it to the communication path 60-5. Communication path 6
The control packets sent to 0-5 are multiplexed switches 6
It is sent to the transmission line 80 via 0-6. Transmission line 8
The control packet on 0 is sent to the communication path 73-5 via the multiplexing switch 73-6 of the RUC 73 in the RU 70 and received by the SIO 73-3. Then C
The PU 73-2 transfers the control packet received by the SIO 73-3 to the M-ILSI 73-1 via the bus 73-4, and the M-ILSI 73-1 sends the control packet to the control highway 74.

As a result, the M-ILSI on the PBX body 1 side
The control packet sent from the 12-1 to the control highway 40 is sent to the control highway 74 in the remote RU 70 as it is. Therefore, the L / T card 72 accommodated in the RU 70 is the LCP in the PBX main body 1.
The control packet from U12 can be received without any trouble.

Next, the L / T card 72 in the RU 70 sends the control packet sent to the control highway 74 to the LCPU.
The case where 12 receives is explained. In this case, L
The control packet sent from the / T card 72 to the control highway 74 by the S-ILSI 72-1 is received by the M-ILSI 73-1 in the RUC 73. CPU7
3-2 transfers the control packet received by the M-ILSI 73-1 to the SIO 73-3 via the bus 73.4, and the SI
The O73-3 sends this to the communication path 73-5. The control packet thus sent to the communication path 73-5 is sent to the transmission path 80 via the multiplexing switch 73-6.

The control packet on the transmission line 80 passes through the multiplexing switch 60-6 and the communication line 60-in the RUI 60.
5 is received and is received by the SIO 60-3.
After that, 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 the time slot corresponding to the card address information on the card address field. As a result, the L / T card 72-1 in the RU 70
The packet information sent by the control highway 74 is PBX.
The data is sent to the control highway 40 in the main body 1, whereby the CPU 12 in the PBX main body 1 receives the L / T card 72.
Can receive control packets from.

In this way, according to the present invention, the same conditions as when the LCPU 12 in the PBX main body 1 directly connects the L / T card 72 to the respective card address positions of the control highway 40 in its own unit. Can be controlled with. On the contrary, the L / T card 72 at the remote place can be controlled by the LCPU 12 under the same condition as that of being directly connected to the control highway 40 of the PBX body 1. At this time, regarding the transmission of the control packet on the transmission line 80, the X. It is possible to activate the transmission error detection and retransmission functions of the 25 protocols, which makes it possible to maintain a strong characteristic against transmission errors due to noise or the like.

In the above communication between the LCPU 12 and the L / T card 72, the LCPU 12 and the RUI 60
The transmission and reception of the control signal between the RUI 60 and the RUC 73 are realized by the following method. That is, LC
The PU 12 can send a control signal to the RUI 60 by sending a packet having the address information of the RUI 60 in the destination address field to the control highway 40. In addition, the RUI 60 is a communication channel 60-
5, the packet having the address information of the RUC 73 in the destination address field is transmitted,
A control signal can be sent to.

Next, basic transmission control of call data between the call path unit 20 in the PBX main body 1 and the L / T card 72 at a remote place will be described. First, the call path unit 20
The call data sent from the L / T card 72 to the L / T card 72 is concentrated on the call path highway 50 by the multiplexing switch 60-6 in the RUI 60 and connected to the transmission path 80, after which it is multiplexed in the RU 70. The switch 73-6 sends the same to the same time slot on the communication path highway 50 on the communication path highway 75. Conversely, L /
The call data sent from the T-system card 72 to the call path unit 20 is sent to the same time slot on the call path highway 50 on the call path highway 75 and is sent to the call path unit 2
Transmitted to 0.

More specifically, the call data sent from the call path unit 20 to the L / T system card 72 is multiplexed on the call path highway 50 in the RUI 60.
6 is input. When the LCPU 12 makes a call, R
A request to connect the multiplexing switch 60-6 is issued to the UI 60. The CPU 60-2 searches the unused channel of the transmission path 80 from the digital leased line channel management table 60-7, and if there is a corresponding channel, secures the channel. At the same time, the CPU 60-2 writes in the management information of the secured channel of the digital leased line channel management table 60-7 that it is secured, and further writes the address unique to the calling terminal. , The call data of the corresponding destination terminal is connected by the multiplexing switch 60-6.

The RUI 60 also requests the RUC 73 to connect the secured channel of the transmission line 80 to the channel of the communication line highway of the corresponding destination terminal. In response to this request, in the RUC 73, the CPU 73.2 uses the multiplexing switch 73-6 to cause the call path highway 7 of the corresponding destination terminal to be transmitted.
Control for connecting the channel 5 and the channel of the transmission line 80 is performed. As a result, the L / T card 72 at the remote location
Is in the same state as when it is directly connected to the call path highway 50 in the PBX main body 1, and the call data can be transmitted and received by the time slot on the call path highway 50 corresponding to each card address. In this way, the L / T card 72 at the remote location has the same LCP condition as the L / T card 32 of the line / trunk section 30 housed in the PBX main body 1 except that there is a certain transmission delay.
Under the control of U12, communication can be performed using the time slot of the communication path highway 50 of the PBX main body 1.

Next, the concentrating / non-concentrating control on the transmission line 80 of the system of the present invention will be described. In the system shown in FIG. 3, when the concentrating / non-concentrating control is performed, the maintenance person must first set the concentrating / non-concentrating data in the LCPU 12 in the PBX main body 1 by a maintenance terminal or the like. The concentrated / non-concentrated data set in the LCPU in this way is then transferred to the R through the control highway 40.
It is downloaded to the UI 60. After completion of this download, L / T card 72-1 housed in RU70
When an incoming call request is made to the terminal connected to, the incoming call request signal is sent from the control highway 40 to the RUI 60,
It is received by the L / T card 72-1 in the RU 70 through the transmission line 80, the RUC 73, and the control highway 74.

Next, in response to the line connection request from the LCPU 12, the RUI 60 transmits the call data by using the time slot already assigned when the data of the terminal of the incoming call request destination (destination) is not concentrated. , In the case of concentrating, an empty time slot is acquired and call data is transmitted. At that time, if the time slot cannot be acquired, the RUI 60 sends a line block notification signal to the LCPU.
12 to the L / T card 72-1 housed in the RU 70, and sends a disconnection instruction signal to the L / T card 72-1. Upon receiving the line block notification signal, the LCPU 12 sends BT (busy tone) to the terminal on the calling side. On the other hand, RU
When making a call from a terminal accommodated in 70, an off-hook signal generated when the calling terminal picks up the handset is transmitted from the L / T card 72-1 to the control highway 74, RU.
C73, transmission line 80, RUI 60, control highway 40
To the LCPU 12 through. Upon receiving this off-hook signal, the LCPU 12 sends a line connection request to the RUI 60. In response to a line connection request, the RUI 60 acquires the already assigned time slot when the data of the calling terminal is not concentrated and transmits / receives the call data, and when the line is concentrated, acquires an empty time slot. Then, the call data is transmitted and received. At that time, if the empty time slot cannot be acquired, the RUI 60
Sends a line block notification signal to the LCPU 12. Upon receiving the line block notification signal, the LCPU 12 transmits a disconnection instruction signal to the L / T card 72-1 housed in the RU 70. In this way, the number of digital leased lines connected to the L / T card is determined by the number of terminals connected to the L / T system card by increasing the utilization efficiency of the transmission line while controlling the concentration / non-concentration on the transmission line 80. Can be less than a minute.

Next, in the system of the present invention, the control operation when a call arrives at the number of the multi-appearance group will be described. In the system shown in FIG. 3, one of the L / T cards 72 in the remotely located RU 70 accommodates a plurality of terminals 76 forming a multi-appearance group. Each of these terminals 76 is given a unique number corresponding to the above multi-appearance group. When a call arrives at the number of the multi-appearance group, the central control unit 10 notifies all the terminals in the group of the incoming call, and the terminal between the terminal responding to the incoming call and the calling side terminal in the group. Are connected by the call path unit 20 to send and receive call data.

As a concrete control operation, when a call arrives at the number of the multi-appearance group, the LCPU 12
Sends to RUI 60 a line reservation request signal including a pre-assign number having a one-to-one correspondence with the group number. In the RUI 60 which receives this, the CPU 6
On the basis of the line reservation request signal, 0-2 searches the digital leased line channel management table 60-7 for only one unused channel of the transmission line 80, and reserves it. Regarding this secured channel, CPU 6
0-2 is a digital leased line channel management table 60
-Indicate in the management information of the channel in 7 that it is reserved, and write the pre-assign number unique to the incoming multi-appearance group corresponding to that channel.

Further, in the LCPU 12, when the call for the number of the multi-appearance group is received, the control highway 40 sends it to the L / T card 72-1 in the RU 70 through the RUI 60, the transmission line 80, the RUC 73, and the control highway 74. The signal alerts all terminals 76 in the incoming call group of incoming calls. Here, when a terminal 76 in the multi-appearance group responds to the call, the response signal is sent from the L / T card 72-1 to the LCPU 12 through a route reverse to the above.
Upon receiving this response signal, the LCPU 12 next
A line connection request signal with the above-mentioned pre-assigned number is sent to 60. In RUI60, MCPU60
-2 refers to this pre-assign number and obtains from the digital leased line channel management table 60-7 the channel on the transmission path 80 which has already been secured corresponding to the pre-assign number. After that, the MCPU 60-2 connects the corresponding channel and the channel on the control highway 40 of the responding terminal 76 by the multiplexing switch 60-6 to transmit the call data of the responding terminal 76.

Further, the RUI 60 sends to the RUC 73 a request to connect the channel number on the connected transmission line 80 and the channel of the response terminal 76. In RUC73,
Based on this channel connection request, the CPU 73.2 connects the corresponding channel on the transmission path 80 and the channel of the response terminal 76 on the communication path highway 75 with the multiplexing switch 73-6. After that, the call data of the response terminal 76 can be transmitted / received to / from the call path unit 20, whereby the call is realized.

As described above, according to the present invention, even when a call arrives at the number of the multi-appearance group, only one channel needs to be secured in the process until a certain terminal in the group responds to the call. In the meantime, it is possible to significantly reduce the cases where call processing on other channels is disturbed and communication cannot be performed. Further, according to the system configuration of the present invention, since the RUI is connected to the control highway of the PBX main unit through the same interface as the L / T system card, the amount of change in the hardware and software of the existing PBX main unit is small. I'm done.
In addition, even in a remote location, the same highway as the control highway of the PBX main unit and the highway with the same protocol as the communication path highway are provided. Therefore, the same L / T card as that accommodated in the PBX main unit is not changed in software or hardware. Can be used as is.

[0040]

As described above, according to the remote line accommodation system of the private branch exchange of the present invention, the connection processing of the incoming call is managed by the digital leased line channel management table, and the call arrives at the number of the multi-appearance group. If
Only one channel on the digital leased line is secured in association with the group number, and after receiving an incoming call from an arbitrary terminal in the group, the channel is connected to the responding terminal to start transmission of call data. It is not necessary to secure the number of channels corresponding to all terminals in the multi-appearance group until the connection channel for the responding terminal is determined, and channels are used on the digital leased line while allocating that number of channels to other call connection processing. It is possible to increase efficiency. Further, according to the call connection processing of the present invention as described above, the number of channels of the digital leased line to be prepared as equipment can be significantly increased even when considering the incoming call to a plurality of terminals forming a multi-appearance group. It has the great advantage that it can be reduced and the whole system can be constructed economically.

[Brief description of drawings]

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

FIG. 2 is a detailed system configuration diagram of the PBX shown in FIG.

FIG. 3 is a diagram showing an example of the configuration of a digital leased line channel management table 60-7 according to the present invention.

FIG. 4 is a system configuration diagram of a conventional PBX of this type.

[Explanation of symbols]

 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 ... Call path unit (TSW) 30 ... Line / Trunk (L / T) section 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 ... Call 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 ... Digital leased line channel management table 70 ... RU (remote unit) 73 ... RUC (remote unit controller) 76 ... Multi-appearance group terminal 80 ... Transmission path

Claims (2)

[Claims] 1. An interface in the remote unit by connecting a digital leased line capable of transmitting control data and call data between interface cards mounted in the private branch exchange main body and the remote unit to accommodate terminals respectively. Call data with the remote terminal while selectively securing an empty channel among the channels on the digital leased line set to a number smaller than the number of remote terminals accommodated in the card in response to a call. In a remote line accommodation system of a private branch exchange that performs transmission, channel management data storage means for storing channel management data corresponding to the usage status of each channel on the digital leased line, and the terminals are identified by the same number for each of a plurality of terminals. To obtain a multi-appearance group, and which terminal in the group is the call arriving at the number of the group An incoming call detecting means for detecting an incoming call related to the multi-appearance function, a channel securing means for securing one vacant channel on the digital leased line for a call received to the number of the multi-appearance group, and the channel Storage control means for storing the channel secured by the securing means in the channel management data storage means in association with the number of the multi-appearance group, and when a terminal in the multi-appearance group responds to the incoming call, A remote line accommodation system for a private branch exchange, comprising: a connection control means for connecting the response terminal to a channel already secured while referring to the management data in the channel management data storage means. 2. The remote line accommodation system for a private branch exchange according to claim 1, wherein the channel management data storage means is provided on a substrate of an interface card mounted in the main body of the private branch exchange.