JPH04179393A - Isdn terminal housing system for private branch exchange - Google Patents

Abstract

PURPOSE:To house plural ISDN terminals in a wide range at a distant place by providing a multiplex transmission path from a multiplex network terminating means to a prescribed place, connecting a multiplex distributing means at the place, and connecting a bus with this multiplex distributing means. CONSTITUTION:A private branch exchange 10 is equipped with a multiplex network terminating device 5 which operates the connection in a layer two level with an ISDN line 110. On the other hand, buses S1-S8 which house ISDN terminals P11-P88 are defined as a basic interface S point, and a multiplex distributor 20 is provided at this S point. Then, the transmission and reception of multiplexed signals is operated through a multiplex transmission path 12 between the multiplex network terminating device 5 and the multiplex distributor 20. Thus, the many ISDN terminals can be housed even when the ISDN terminals are scattered in the wide site.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to an ISDN end unaccommodating system in a private branch exchange, and particularly to an ISDN terminal system suitable for use in a private branch exchange that accommodates a large number of ISDN terminals over a wide range. Regarding the edge unaccommodated method.

(Prior art) The user/network interface in ISDN (Integrated Service Digital Network) is explained in "■ Series International Standards and Their Technologies" supervised by Shozo Iwasaki, published by Telecommunications Association, pp. 50-124. It is constructed based on the specifications of the CCITT Recommendation I.400 series.

Among these, for example, a private branch exchange (PBXI) with an ISDN
When accommodating terminals, the horizontal switch is positioned at the network termination level 2 fNT21 in the function group, and layer 2.
The three points in the three basic interfaces, which have three terminal functions and three connection points between this private branch exchange and the terminal equipment, consist of two B channels of 64 kbps and one D channel of 16 kbps. It has a 2B+D structure, and its interface speed is 192 kbps, including a synchronization signal.

In addition, the wiring cables for the electrophysical interface layer I at the three points are to be configured with two pairs of transmitting lines and receiving lines (two lines each, a total of four wires), and the wiring form is (al Simple bus format, (bl extended bus format, (
C) There were various wiring types such as point-to-point type.

(Problem to be Solved by the Invention) However, in the conventional technology, wiring is directly connected to the private branch exchange in the above-mentioned bus format.

In this case, the maximum connection line length was 100 to 200 m for a simple bus type, 500 m for an extended bus type, and 1 ka+ for a point-to-point type. Therefore, when terminal devices are spread out on a large site or when buildings are separated, there is not enough wiring length and there is no flexibility in selecting the wiring format. There was a problem that ISDN terminals could not be accommodated over a wide area.

In addition, even within the range where it is possible to accommodate terminal devices, the three basic interface points are 2-to-4-wire, so when accommodating multiple buses, it is necessary to wire a large number of cables, and wiring work is required. There were problems such as the complexity of the process.

The present invention overcomes these drawbacks of the prior art.

It is an object of the present invention to provide a method for not accommodating ISDN terminals in a private branch exchange that can accommodate a large number of ISDN terminals over a wide area, increase the degree of freedom in wiring formats, and further reduce the number of wiring cables. purpose.

(Means for Solving the Problems) In order to solve the above-mentioned problems, the present invention provides a system in which ISDN terminals are not accommodated in a local exchange that accommodates ISDN lines. , and a multiplexed network terminating means for generating and transmitting state management signals such as activation/stopping of ISDN terminals, and transmitting/receiving signals transmitted between the ISDN line and the ISDN terminals as multiplexed signals, This multiplexed network termination means 1
This multiplex transmission line accommodates a multiplex transmission line for transmitting multiplexed signals, and multiplexes and transmits signals transmitted from ISDN terminals on this multiplex transmission line, and multiplexed signals received from the local exchange side. A multiplexing and distributing means for distributing ISDN to each ISDN terminal is connected, and this multiplexing and distributing means accommodates a plurality of buses to which ISDN terminals are connected, and this multiplexing and distributing means distributes a plurality of 8 points of ISDN. It is characterized by accommodating.

Further, the multiplex network termination means includes a downlink buffer for buffering signals transmitted from the ISDN line side, and a TSD
An upstream buffer that buffers signals to be transmitted to the N line side, a timing circuit that generates timing signals for these buffers, an insertion circuit that inserts a control signal into the signal sent from the downstream buffer, and a control signal that is supplied to the upstream buffer. An extraction circuit that extracts a control signal from a signal, a layer 2 means that generates a control signal and a state management signal to be inserted in an insertion circuit and transfers the extracted control signal, and a signal into which the control signal is inserted by the insertion circuit. The device is characterized by comprising a driver circuit that adds a synchronization signal to and transmits the multiplexed signal, and a receiver circuit that receives the multiplexed signal based on the synchronization signal transmitted from the terminal side.

Further, the multiplexing distribution means includes a plurality of layer 1 circuits accommodating a plurality of terminals in the form of a bus, a distribution circuit that distributes signals received via the multiplex transmission path to these layer 1 circuits, and A multiplexing circuit that multiplexes signals to be transmitted, a driver circuit that adds a synchronization signal to the signal multiplexed by the multiplexing circuit and transmits it, and receives a signal transmitted from the exchange side based on the synchronization signal. and a receiver circuit.

(Function) According to the method of not accommodating ISDN terminals in a local switching system according to the present invention, the horizontal switching system is installed at a predetermined location, and multiplexed transmission lines are connected from the multiplexed network termination means provided in the horizontal switching system to a predetermined location. By installing the cable to a location, connecting multiplexing and distributing means at that location, and connecting a bus in the 2B+D channel format to this multiplexing and distributing means, multiple IS
DN terminals can be accommodated in remote locations over a wide range.

(Embodiment) Next, an embodiment of the ISDN end unaccommodated system in a private branch exchange according to the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 shows an ISDN in a private branch exchange according to the present invention.
An example of an edge unaccommodated scheme is shown.

In this example, the private branch exchange (PBXII (l) is the trunk fTRKl 2.4 and the subscriber circuit (SLIC1
3, a multiplexed network termination device (INFI 5), a time division switch (TSlf+ 6), and a control device fcPUl 8. 'Trunk 2 accommodates an analog line 100 consisting of a general public line or a private line. , trunk 4 accommodates an ISDN line 11 (l) consisting of an ISDN office line or a dedicated line.

The subscriber circuit 3 accommodates an existing analog terminal IrI 22.

The multiplexed network terminal device 5 accommodates the multiplexed transmission line 12,
Multiplexing distribution device 2 accommodating ISDN terminals pH~P88
Connected to 0.

The time division switch 6 sets up a connection bus between the trunk 2 accommodating the analog line 1'10 and the subscriber circuit 3;
and connection bus settings between the trunk 4 accommodating the ISDN line 110 and the multiplex network termination device 5.

Furthermore, it is a network circuit that interconnects them.

The control device 8 sends control signals via a control bus 810 connected to each of the circuits 2 to 6, and controls each section.

On the other hand, the multiplexed transmission line 1 accommodated in the multiplexed network terminal device 5
2, as shown in FIGS. 1 and 2, the transmission line 12a
This multiplex transmission line 12, which is a transmission line consisting of 2411 pairs consisting of a receiving line 12b, is made of a cable medium such as a twisted pair wire, a shielded bare wire, a coaxial cable, or an optical cable, and the length thereof is selected as appropriate. By doing so, it is possible to freely set the transmission distance from the multiplex network terminal bag f15 to the multiplex distribution device 20.

The multiplexing distribution device 20 accommodates eight groups of buses 5l-58, each of which is equipped with connection terminals for up to eight lines, and connects ISDN terminals p for a total of 64 lines.
It is possible to accommodate HP88.

The buses 5l-58 are each configured in a simple bus format, an extended bus format, etc.

Next, the internal configurations of the multiplex network termination device 5 and the multiplex distribution device 20 will be explained in more detail with reference to FIG.

In this figure, the multiplex network termination device 5 is connected to a backward buffer 51 connected to the downlink communication line (BHIII 13a) of the time division switch 6, and an uplink communication line (1! IB) JW) 13b of the time division switch 6. The backward buffer 51 is a storage circuit that buffers signals input from the downlink communication line 13a connected to the time division switch 6.The forward buffer 52 has a forward buffer (FBFI 52). 20 through the receiving line 12b of the multiplexed transmission line 12, and sends the buffered signal to the uplink communication line 13b connected to the 1-time division switch 6.The backward buffer 51 is Inser 9 (INS
155, Rai:/H Raiha (connected to the transmission line 1sHwI 12a of the multiplex transmission line 12 via the DV 157e. The forward buffer 52 is connected to the dropper (DR
P156 is connected to the receiving line (RHWI 22b) of the multiplexed transmission line 12 via the line receiver (RVI 58).

Buffers 51 and 52 are timing extraction/distribution circuits fT.
A signal buffering operation is performed in synchronization with the timing signal sent from the I-cap 53.

The inserter 55 is a circuit that adds control information to the signal read from the backward buffer 51. The line driver 57 is a transmitting circuit that transmits the multiplexed signal sent out via the inserter 55 to the multiplexing distribution device 20 via the transmission line 12a of the multiplexing transmission line 12. The line receiver 58 is a receiving circuit that receives the multiplexed signal transmitted from the multiplex distribution W I20. The dropper 56 is
This circuit extracts control information from the signal received by the line receiver 58.

Inserter 55 and dropper 56 exchange control information with control signals sent from control processor fcNTl 60 and link fL2161. Exchange of these control information is performed via a control line 63 and a control bus 64.

The control processor 60 is connected to the control device 8 via a control bus 810, transmits and receives control information to and from the control device 8, and controls each part of the multiplexed network terminal device 5.

On the other hand, the multiplex distribution device 20 includes a line receiver (RV 171) that receives a multiplexed signal input from the transmission line 12a of the multiplex transmission line 12, and a receiving line 12b of the multiplex transmission line 12.
The line driver + DV) 72 is provided to send out multiplexed signals. These line receivers 71 and line driver buffers 2 are connected to a timing extraction/distribution circuit (TIMI).
The line receiver 71 performs transmission and reception operations in synchronization with the timing signal sent from the line receiver 73.

The received signal is sent to the distribution circuit 75.

The distribution circuit 71 sends the received signal to the buses S-1 to S-8 accommodating the destination terminals to the layer 1 circuit +LS1181 to 88.
This is a circuit that distributes the data via the Layer 1 circuit 81-88
are the layers that start and stop ISDN terminals, respectively.
level circuit, and 2B distributed from the distribution circuit 75.
+D channel signals are sent to buses 51 to S8, and I
The signal transmitted from the SDN terminal pH-P88 is sent to the multiplexing circuit 76.

The multiplexing circuit 76 is a circuit that multiplexes eight lines of signals received from the ISDN terminal and sends them to the multiplex transmission line 12 via the driver 72.

Next, these multiplex network termination circuits 5 and multiplex distribution circuits 2
The multiplexed signal transmitted/received between 0 and 0 will be explained with reference to FIG.

Up/down communication line 1 between time division switch 6 and network termination device 5
In 3a, 13b - 2.048MH for boat fishing
z or 8.192 MHz signals are transmitted and received. 2.
The case of 048 klHz is shown in FIG. 3 fat. In the upstream and downstream communication lines 13a and 13b, the basic cycle is 8kHz and the amount of information is 8 bits, so 64
32 channels can be secured per frame at a transmission speed of kbps. In the case of 8.192MHz, 1
The frame has a configuration of 128 channels. These 64kb
A B channel signal is assigned to the ps channel.

This B channel signal is input from the ISDN line 110 via the time division switch 6 to the downlink communication line J3b to the multiplex network termination device 5, and is buffered in the backward buffer 51. Also.

The control device 8 of the exchange transfers the D channel signal to the control processor 60 of the network termination device 5 via the control bus 810 and activates the links 61, respectively, thereby establishing a layer 2 level connection. The link 61 is connected to the inserter 55 or the dropper 56, and its control information is inserted into and extracted from the multiplex transmission line 12. Similarly, the control processor 60 controls the multiplexed transmission line 1
It transmits and receives signals to the channel assigned to layer 2 via the inserter 55 or the driver 56, and manages the activation/stopping procedure of layer 1.

To explain the procedure for starting and stopping this layer I, first, when an ISDN terminal is in a stopped state and there is an incoming call to that terminal, a state management signal C is synchronized from the link 61 of the network termination device 5 via the inserter 55. Transmit the activation signal. When this synchronization activation signal is received by the multiplexing distribution device 20, the synchronization activation signal is transmitted to the layer 1 circuit 81 (~88). When the layer 1 circuits 81f to 88) receive the synchronization activation signal, they send out a synchronization response signal as the state management signal C.

This synchronization response signal is transmitted to the network termination device 5 via the multiplexing circuit 76 and then transmitted to the link 6J via the dropper 56. When the link 61 receives this signal, it sends out the synchronization response signal again, and this signal is received by the layer 1 circuit 81 (~88) in the multiplexing and distribution device 20 in the same way as above, and as a result, the terminal It is activated and both exchanges are in a communication state. Also, when making a call from the terminal side,
An asynchronous activation signal is sent from the terminal side, and the exchange side that receives this sends a synchronous activation signal, and both sides respond synchronously, thereby establishing a communication state.

In this embodiment, as shown in Fig. 3 fbl,
An example is shown in which a 28+D channel signal and a layer I startup/stop procedure signal C are divided into 8 lines and distributed to the multiplexed transmission line 12. Since the B channel signal is 8 bits, it occupies one channel, but the D channel signal is 2 bits, so
The activation/stop procedure signal C can be assigned to the remaining 6 bits.

The multiplexed signals allocated in this manner are sent by the line driver 57 to the transmission line 12a of the multiplex transmission path 12 with the frame synchronization signal SY at the beginning.

This multiplexed signal is received by the line receiver of the multiplexing distribution device 20 and input to the distribution circuit 75. The distribution circuit 75 distributes the signal to the layer 1 circuit 81 accommodating the buses Sl to S8 corresponding to the signal. Layer 1 circuit 8I activates each ISDN terminal as described above and connects each ISDN terminal via respective bus 5l-38.
Send a signal to the terminal.

On the other hand, signals transmitted from ISDN terminals are layer 1
The signals are respectively sent to multiplexing circuit 76 via circuits 8l-t-. The multiplexing circuit 76 multiplexes these signals as shown in FIG.

When the multiplexed signal input to the receiving line 12b of the multiplexed transmission line 12 and the multiplexed network terminal device 5 is received by the line receiver 58, the D channel signal and control information C are extracted by the dropper 56. A B channel signal is sent to forward buffer 52. As shown in FIG. 3, the forward buffer 52 buffers the B channel signal and sends it to the uplink communication line 13b of the time division switch 6. The D channel signal is transferred to the control device 8 via the control processor 60, and together with the B channel signal,
It is sent to the ISDN line 110.

Therefore, in the ISDN terminal non-accommodating system in this embodiment, the private branch exchange IO is equipped with a multiplexed network termination device 5 that connects the ISDN line 110 at the layer 2 level, and a bus that accommodates the ISDN terminal pH-P88. 5l-3
8 is the basic interface point S, and multiplex distribution devices 20 are provided at these three points, and multiplexed signals are transmitted between the multiplex network terminal device 5 and the multiplex distribution device 20 via the multiplex transmission line 12. For example, if the ISDN terminal pH~P88 is installed in a building different from the building in which the private branch exchange IO is installed, the multiplex transmission line 12 is laid between the buildings, and the ISDN terminal In the building where it will be installed,
A multiplex distribution device 20 is installed, and this multiplex distribution device 2
By connecting each bus PI-P8 to
It is possible to perform wiring that is compatible with the arrangement of terminals. Also,
Even when ISDN terminals are scattered within a large site, by laying the multiplex transmission line 12 from the installation location of the horizontal exchange to the vicinity of the location where the ISDN terminal is installed, a free wiring configuration can be achieved at that location. The buses 31 to S8 are connected to each other, and a large number of ISDN terminals can be accommodated.

In this case, since the multiplex transmission line 12 has a two-wire, one-pair configuration, wiring can be easily performed.

(Effects of the Invention) As explained above, according to the ISDN terminal accommodating method in the private branch exchange according to the present invention, the private branch exchange has layer 2
Equipped with a multiplexed network termination device that performs level connections,
A multiplex distribution device that multiplexes and transmits signals to 5UN terminals is installed on the terminal side, and signals are multiplexed via a multiplex transmission path between these multiplex network terminal devices and the multiplex distribution device. ■Since communication is performed using the standard wiring configuration of the interface, remote accommodation is possible, and S, r! 5.
The range of terminal connections at 8 points is widened, and the degree of freedom in selecting the wiring format at 8 points is increased.Also, an excellent effect can be obtained in that the amount of cables to remote locations can be reduced.

[Brief explanation of the drawing]

FIG. 1 is a relay system diagram showing an embodiment of the ISDN end unaccommodated system in a horizontal switch according to the present invention, and FIG. 2 shows the internal configuration of a multiplex network termination device and a multiplex distribution device in the same embodiment. Relay system FIG. 3 is a configuration diagram showing multiplexed signals in the same embodiment. Explanation of the symbols in the main part 2, 4, , rank 3, subscriber circuit 5, multiplex network termination device 8, , central control device 10...
, , , , , , Private branch exchange 12 , , , , , , , ,
Multiplex transmission line 20, - Multiplex distribution device 5l-38 bus pH-P88, ISDN terminal 51.52,
, , , , Buffer 55 , , , , , Inserter circuit 53 , ,
,,,,, Timing circuit 56 ,,,,,,,
Dropper circuit 60 , Control processor 61 ... Link 75 , Multiplexing circuit 76 , ...
, , , , distribution circuits 81 to 88 , , , , layer 1 circuit 57.72
,,,,, Driver 5B, 71 ,,,,,,
Receiver patent applicant Oki Electric Industry Co., Ltd. Agent Takao Writer

Claims (1)

[Claims] 1. ISD in a private branch exchange accommodating an ISDN line
In the N terminal accommodating system, the private branch exchange has a network termination function for the ISDN line, generates and sends out status management signals such as activation/stop of the ISDN terminal, and provides communication between the ISDN line and the ISDN terminal. multiplexed network terminating means for transmitting and receiving signals transmitted as multiplexed signals, the multiplexed network terminating means accommodates a multiplexed transmission line for transmitting the multiplexed signals, and the multiplexed transmission line A multiplexing and distributing means for multiplexing and transmitting the signals transmitted from the ISDN terminal and distributing the multiplexed signal received from the private branch exchange to each ISDN terminal is connected to the multiplexing and distributing means, and the ISDN A system for accommodating ISDN terminals in a private branch exchange, characterized by accommodating a plurality of buses to which terminals are connected, and accommodating a plurality of S points by the multiplexing and distributing means. 2. In the ISDN terminal accommodating system in a private branch exchange according to claim 1, the multiplex network termination means includes a downlink buffer for buffering signals transmitted from the ISDN line side, and a downlink buffer for buffering signals transmitted to the ISDN line side. a timing circuit that sends timing signals to these buffers, an insertion circuit that inserts a control signal into the signal sent via the downlink buffer, and an extraction circuit that extracts the control signal from the signal supplied to the uplink buffer. an extraction circuit; a layer 2 means for generating a control signal and a state management signal to be inserted in the insertion circuit and transferring the extracted control signal; and adding a synchronization signal to the signal into which the control signal has been inserted in the insertion circuit. A private branch exchange system comprising: a driver circuit for transmitting a multiplexed signal; and a receiver for receiving a multiplexed signal based on a synchronization signal transmitted from a terminal side.
SDN terminal accommodation method. 3. In the ISDN terminal accommodating system in a private branch exchange according to claim 1, the multiplexing and distributing means includes a plurality of layer 1 circuits accommodating a plurality of ISDN terminals in a bus format, and multiplex transmission to these layer 1 circuits. a distribution circuit that distributes the multiplexed signal received via the ISDN terminal, a multiplexing circuit that multiplexes the signal transmitted from the ISDN terminal, and a synchronization signal added to the signal multiplexed by the multiplexing circuit for transmission. 1. A system for accommodating ISDN terminals in a private branch exchange, comprising: a driver circuit for receiving a signal transmitted from the exchange side based on a synchronization signal; and a receiver circuit for receiving a signal transmitted from the exchange side based on a synchronization signal.