JP2590684B2 - Subscriber line multiplexer and system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention is used for digital communication. In particular, the present invention relates to a technology for saving a transmission line of a digital exchange.

[0002]

2. Description of the Related Art In a conventional subscriber line multiplexer, different types of subscriber line multiplexers are prepared for each type of terminal for each signal system of the terminal. There is a method of preparing a function for supporting a plurality of types of terminals. In that case, the former has the advantage that the function is simpler and can be configured at lower cost than the latter. In the former method, multiplexing / demultiplexing is performed by a multiplexing method such as time division multiplexing for voice or data signals for each terminal signal, and signals for each terminal are combined for a control signal for call processing. For example, a method of performing communication with an electronic exchange through one channel has been adopted. As a multiplex transmission line connecting the subscriber line multiplexer and the electronic exchange, a high-multiplex transmission line such as 2 Mbps or 1.5 Mbps is generally used, and 20 to 30 terminals (for example, (64 kbps each) is accommodated in a subscriber line multiplexer (Japanese Patent Laid-Open No. 57-143954).
JP-A-61-172456, JP-A-62-241
455, JP-A-63-318841, and JP-A-3-124146).

[0003]

In the conventional subscriber line multiplexer, when a plurality of types of terminals are used, a subscriber line multiplexer for accommodating each terminal is required. . Therefore, when there are a small number of terminals of a plurality of types at a place where the subscriber line multiplexer is installed, the former method requires a plurality of subscriber line multiplexers, and the A number of multiplexed transmission lines were required. However, when a small number of terminals are accommodated in each subscriber line multiplexer and the subscriber line multiplexers are installed relatively close to each other, it is not economical to provide a multiplex transmission line.

The present invention has been made under such a background, and has as its object to provide a subscriber line multiplexer capable of accommodating a plurality of types of terminals with a small number of multiplex transmission lines. .

[0005]

The first aspect of the present invention, in order to solve the problem] is a subscriber line multiplexing scheme, it is an feature double
A number n of subscriber line multiplexers and these subscriber line multiplexers
Exchange which accommodates the multiplexing device via the time division multiplex transmission line
The subscriber line multiplexer comprises a plurality of line circuits each accommodating a plurality of digital communication terminals, and time division signals of the plurality of line circuits.
A multiplexing control circuit for multiplexing and demultiplexing;
Subscriber with an interface connected to a heavy transmission line
In the line multiplex system, only the first subscriber line multiplexer
Is connected to the electronic exchange via the time division transmission line.
Signal of a plurality of line circuits multiplexed by the multiplex control circuit.
Channel groups for each subscriber line multiplexer in advance
Convert to the defined first channel group and convert the first signal line
Output to the output direction signal line, input direction signal of the first signal line
Before the second channel group of the time-division multiplexed signal
Channel to be converted to channel group corresponding to the line circuit
A conversion circuit, input to the input direction signal line of the second signal line;
The signal of the first channel group is output from the multiplex control circuit.
Time division multiplexed with power signal and output from the interface
Converting the signal of the second channel group of the multiplex signal line into the second signal
A multiplexing circuit for outputting to a signal output direction signal line;
An output method of the first signal line of another subscriber line multiplexer.
Signal line is a second signal of the first subscriber line multiplexer.
The first subscriber line multiplexed connected to the line incoming signal line
The output direction signal line of the second signal line of the device is the other
Connected to the input direction signal line of the first signal line of the subscriber line multiplexer . It is desirable that n = 2.

According to a second aspect of the present invention, there are provided a plurality of line circuits each accommodating a plurality of digital communication terminals, an interface accommodating a transmission path for multiplexed signals, and input signals from the plurality of line circuits, respectively. A multiplexing control circuit including means for multiplexing individual signals and sending them to the interface as a time-division multiplexed signal, and means for multiplexing and demultiplexing the time-division multiplexed signals arriving at the interface and outputting the multiplexed signals to the line circuits as individual signals. A subscriber line multiplexing device provided.

Here, a feature of the present invention is that a signal of a channel not used for any of the plurality of line circuits among channels of the time division multiplexed signal is mutually converted into a signal of an arbitrary channel number. And a multiplexing circuit for connecting the signal of the channel conversion circuit of the partner device to the interface.

[0008]

In a digital communication line using a signal in which a plurality of channels are multiplexed, when each terminal uses a channel at the same position (the same channel number), it is always used without being used by any terminal. There is a channel that is “empty”.

Using the vacant channel, the signal of another subscriber line multiplexer is multiplexed at a predetermined position and transmitted to the transmission line. The electronic exchange extracts the signal from the predetermined position.

[0010] With this, the multiplex transmission line can be shared and used by a plurality of subscriber line multiplexers, so that the multiplex transmission line can be used efficiently.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The construction of an embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a block diagram of an apparatus according to an embodiment of the present invention. FIG. 2 is a diagram showing the overall configuration of the embodiment of the present invention.

[0012] The present invention is a subscriber line multiplexer for use in multiplexing schemes and which subscriber lines, and has as its features, a plurality of lines in which a plurality of digital communication terminal 11 ₁ 1n ₁ are accommodated respectively a circuit 21 ₁ to 2n _1, interface 7 the transmission path 8 ₁ of the multiplex signal is received
₁ and, with a time-division multiplexed signal arriving individual signals input from the plurality of line circuits 21 ₁ to 2n ₁ the means and the interface sends to the interface ₇₁ as a time-division multiplexed signal by multiplexing and demultiplexing multiple control circuits 3 ₁ subscriber line multiplexer 10 ₁ and a n Taisonae, subscriber line multiplexer for the n base 1 including means for outputting a respective individual signal to the line circuit 21 ₁ to 2n ₁
0 ₁ to 10 _n , each of which converts a signal of a channel not used by any of the plurality of line circuits 21 _{1 to 2} n ₁ among channels of the time division multiplexed signal into a signal of an arbitrary channel number. conversion circuit 4 ₁ to 4
and _n, the multiplexing circuit 51 _to which connects the signal of the channel conversion circuit 4 ₁ to 4 _n of the remote device to the interface 7 ₁ to _7-n
5 _n and n subscriber line multiplexers 10 ₁ to 10 ₁
Interface 7 ₁ of one of the _n is in place connected to the transmission path 8 _1. The embodiment of the present invention will be described on the assumption that n = 2.

FIG. 2 shows the overall configuration of the embodiment of the present invention. The subscriber line multiplexer 10 ₁ and 10 ₂ provided through the transmission path ₈₁ to the electronic exchange 50, a channel conversion circuit 4 ₁ and 4 ₂ of the two subscriber line multiplexer 10 ₁ and 10 ₂ connected multiplexing circuit 5 ₁ and 5 ₂ and are mutually, as shown in Figure 1, the synchronizing circuit 6 ₁ and 6 ₂ as a means of synchronizing the two subscriber line multiplexer 10 ₁ and 10 ₂ clocks It is configured with. Transmission line 8 ₂ shown by a broken line can Government Railway Line by the invention embodiment apparatus in FIG.

Next, the operation of the embodiment of the present invention will be described with reference to FIGS. FIG. 3 is a block diagram showing a case where two apparatuses according to the present invention are connected. FIG. 4 is a diagram showing a channel configuration and its use status. Transmission line 8 _1, in the present invention embodiment, a division multiplexed transmission path when the 2 Mbps, on the transmission path 8 ₁ 32 channel exists. Terminal 1
1 _{1-13 1} and 11 ₂ to 12 ₂ and between the subscriber line multiplexer 10 ₁ and 10 ₂ are transmitted in 64 kbps. In the 2 Mbps time division multiplexing system recommended by CCITT, channel (hereinafter, referred to as CH) 0 is used for the signal system, and therefore, CH1 to CH31 are used as the voice or data path of the subscriber. . The CH 16 is used for a signaling system between the subscriber line multiplexers 10 ₁ and 10 ₂ and the electronic exchange 50.

Line circuits 21 ₁ to 23 ₁ and 21 ₂ to 21
22 ₂ via accommodates a single type of terminal 11 ₁ to 13 ₁ and 11 ₂ to 12 _2, these terminals 11 ₁ to 13
And a multiplex control circuit 3 ₁ and 3 ₂ for controlling the ₁ and 11 ₂ to 12 _2. Multiple control circuits 3 ₁ and 3
₂ is a line circuit 21 ₁ to 23 ₁ and 21 _{2 to} 22 ₂
Multiplexes the information in the upstream direction of the voice or data, and demultiplexes the data in the downstream direction. Multiplex control circuit 3 ₁
And 3 ₂ are terminals 11 _{1 to} 13 ₁ and 11 _{2 to} 12
_{The two} control signals for call processing are collectively output to the CH 16 in the uplink direction, and the information of the CH 16 is distributed to each line circuit in the downlink direction.

The channel conversion circuit 4 ₁ and 4 ₂ are terminal 11 ₁ to 1 outputted from the multiplexing control circuit 3 ₁ and 3 ₂
3 ₁ and 11 and ₂ to 12 multiplexes the _second voice or data signal and a call processing control signals to any channel, and outputs to the outside via the interconnect output signal lines 91 ₁ and 91 _2. Conversely, the channel conversion circuit 4 ₁ and 4
_2, via the interconnect output signal lines 91 ₁ and 91 _2, returns the signal of the channel inputted from the outside to the original time slot. Although not shown in detail in FIG. 1, the channel conversion circuits 4 ₁ and 4 ₂ are generally known time division switches, and are time division multiplexed output from the multiplex control circuits 3 ₁ and 3 ₂ . A time slot is exchanged by writing a signal to the memory once and reading it out at a desired timing.

The multiplexing circuit 5 ₁ and 5 ₂ multiplexes a signal input from the outside via the interconnect input signal lines 92 ₁ and 92 _2, and a signal of the multiple control circuit 3 ₁ and 3 ₂ . Multiplexing circuit 5 ₁ and 5 ₂ are reversed, a signal from the electronic exchange 50 supplied from the interface ₇₁ and 7 ₂ demultiplexes contrary to the above, mutual respectively multiplexing control circuit 3 ₁ and 3 ₂ and it sends to the connected input signal lines 92 ₁ and 92 _2. Does not show a block diagram of details also multiplexing circuit 5 ₁ and 5 ₂ in FIG. 1, but multiplexing circuit 5 ₁ and 5 ₂ via the interconnect input signal lines 92 ₁ and 92 ₂ are predetermined or transmitting internal signals to the next stage of the interface 7 ₁ and 7 ₂ at the timing, determining whether to transmit a signal from the interconnect input signal lines 92 ₁ and 92 ₂ in the next stage of the interface 7 ₁ and 7 ₂ In the reverse direction, it operates as a demultiplexing circuit and can be easily configured.

The synchronization circuit 6 ₁ and 6 ₂ are channel conversion circuit 4 ₁ and 4 ₂ and the multiplexing circuit 5 ₁ and 5 ₂ is operating when acting as a subscriber line multiplexer 10 ₁ or 10 ₂ is the master via interconnecting clock signal lines 93 ₁ and 93 ₂ a clock signal necessary for outputting to the outside, the channel conversion circuit according to a clock signal input from the outside as the slave mode 4 ₁
And 4 ₂ and multiplexing circuits 5 ₁ and 5 ₂ operate, the interconnecting clock signal lines 93 ₁ and 93
₂ converts the clock signal received through channel conversion circuit 4
Transmitting ₁ and 4 ₂ and to the multiplexing circuit 5 ₁ and 5 _2.

In FIG. 3, a subscriber line multiplexer 10 _{1 is shown.}
Subscriber line multiplexer 10 ₂ and is interconnected with output signal line 91 ₁ and the interconnecting input signal line 92 ₂ is connected, interconnecting the input signal line 92 ₂ and the interconnect output signal line 91
₂ and are connected. It is also connected to each other interconnecting clock signal line 93 ₁ and 93 _2. Subscriber line multiplexer 10 ₁ is connected by an electronic switch 50 to the transmission line _81, it operates as a master, subscriber line multiplexer 10 ₂ is operated as a slave. Subscriber line multiplexer 10 ₁ and subscriber line multiplexer 10 _2, different terminals 11 of the signal system _{1-13 1} and the terminal 11 _{2-12 2}
And each housed. Here, the terminal 11 ₁ to 13 ₁ containing the subscriber line multiplexer 10 ₁ and 10 ₂ in order to simplify the description, 11 _{2-12 2} although the small number, the number more terminals The same applies to the case in which

As shown in FIG. 4, the subscriber line multiplexer 1
0 ₂ connects the terminals 11 _{2 to} 12 ₂ to the line circuits 21 _{2 to} 22
Housed by _two . Multiplexing control circuit 3 _2, terminal 1
1 _{2-12 2} audio signal as shown in FIG. 4 (b), C
The multiplexed signal is multiplexed into H1 and CH2, and a call processing control signal is transmitted to CH16. Channel conversion circuit 4 _2,
The above signals are exchanged in time slots and output to CH4 to CH6 in FIG. 4C.

Meanwhile, the subscriber line multiplexer 10 _1, multiplexing control circuit 3 signals from _one and interconnecting the input signal lines 92 ₁
Multiplexes the signals from at multiplexing circuit 5 _1, and sends to the electronic exchange 50. In the electronic exchange 50, CH 1 through CH 3 in the transmission path 8 ₁ as shown in FIG. 4 (d) and CH16
Treat the terminal 11 ₁ to 13 ₁ of the signal, CH4～CH
Handle 6 as the terminal 11 _{2-12 2} signals. Conversely, the signal sent to the subscriber line multiplexer 10 ₁ via the transmission path ₈₁ from the electronic exchange 50, after being signal converted by the interface ₇₁ is demultiplexed by the multiplexing circuit 5 ₁ CH1 ~CH3 and CH16 is transferred to the multiplexing control circuit 3 _1, CH4~CH6 interconnect input signal line 92
It is input to the channel conversion circuit 4 _second subscriber line multiplexer 10 ₂ through the _1.

[0022] In the channel conversion circuit 4 _2, CH4~CH
6 time slots, CH1 to CH2 and CH1
Placed in 6 sends to the multiplex control circuit 3 _2. The synchronous circuit ₆₁ in these operations subscriber line multiplexer 10 ₁
Clock signal lines 93 ₁ , 9
3 ₂ via, sent to the synchronization circuit 6 _2, the synchronization circuit 6 ₂
Distributes the clock signal received on the channel conversion circuit 4 ₂ and the multiplexing circuit 5 _2, exchange thereof in synchronization with the channel conversion circuit 4 ₁ and the multiplexing circuit 5 _first subscriber line multiplexer 10 ₁ Information To be able to

In the embodiment of the present invention, the transmission line 8 is 2 Mb
Although the example of the time division multiplex transmission line of ps is shown, the multiplexing degree and the multiplexing method of the transmission line 8 can be arbitrarily selected.
Also, the case where two subscriber line multiplexers 10 ₁ and 10 ₂ are interconnected has been described, but it is also possible to configure three or more interconnects.

[0024]

As described above, according to the present invention,
When a plurality of types of subscriber line multiplexers corresponding to a plurality of types of terminals are required, even when the number of terminals of each type is small, a multiplex transmission line connecting to an electronic exchange is used efficiently. be able to.

[Brief description of the drawings]

FIG. 1 is a block diagram of an apparatus according to an embodiment of the present invention.

FIG. 2 is a diagram showing the overall configuration of an embodiment of the present invention.

FIG. 3 is a block diagram showing a case where two apparatuses according to the embodiment of the present invention are connected.

FIG. 4 is a diagram showing a channel configuration and its use status.

[Explanation of symbols]

3,3 _1, 3 ₂ multiplexing control circuit 4,4 _1, 4 _2-channel conversion circuit 5,5 _1, 5 ₂ multiplexing circuit 6,6 _1, 6 ₂ synchronization circuit 7,7 _1, 7 ₂ interface 8,8 ₁ , 8 ₂ transmission line 10, 10 ₁ , 10 ₂ subscriber line multiplexing device 11-1n, 11 ₁ -13 ₁ , 11 ₂ -13 ₂ terminal 21-2n, 21 ₁ -23 ₁ , 21 ₂ -23 ₂ Line circuit 50 Electronic exchange 91, 91 ₁ , 91 ₂ Output signal line for interconnection 92, 92 ₁ , 92 ₂ Input signal line for interconnection 93, 93 ₁ , 93 ₂ Clock signal line for interconnection

Claims (3)

(57) [Claims] 1. A plurality of n subscriber line multiplexers, and
Of these subscriber line multiplexers via time division multiplex transmission lines.
The subscriber line multiplexer comprises a plurality of line circuits each accommodating a plurality of digital communication terminals, and time division multiplexing and signal processing of signals of the plurality of line circuits.
And a multiplex control circuit for demultiplexing and demultiplexing, and a subscriber line multiplexing system including an interface connected to the time division multiplexing transmission line , wherein only the first subscriber line multiplexing device has the electronic exchange and the
The signals of a plurality of line circuits multiplexed by the multiplex control circuit are connected through a time-division transmission path .
Channel groups are determined in advance for each subscriber line multiplexer.
Output to the first signal line
Output to the direction signal line, and to the input direction signal line of the first signal line
The second channel group of the input time-division multiplexed signal is
Channel conversion to convert to a channel group corresponding to the in circuit
Circuit, the first signal input to the input direction signal line of the second signal line
Multiplex the signal of the channel group with the output signal of the multiplex control circuit
And a time division multiplexed signal line output from the interface.
The signal of the second channel group is output to the output direction of the second signal line.
A multiplexing circuit for outputting to the signal line , wherein the output of the first signal line of the another subscriber line multiplexer is provided.
The direction signal line is a second signal line of the first subscriber line multiplexer.
Output line signal of the first subscriber line multiplexer connected to the input line signal line of the first line.
Line is a first signal line of the another subscriber line multiplexer.
A subscriber line multiplexing system connected to an input direction signal line . 2. The subscriber line multiplexing system according to claim 1, wherein n = 2. 3. An electronic exchange via a time division multiplex transmission line.
Are connected, a plurality of line circuits in which a plurality of digital communication terminals are respectively accommodated, it of the plurality of lines circuits
Multiplex control circuit for time-division multiplexing and demultiplexing of each signal
And an interface connected to the time division multiplex transmission line.
And a multiplexing control circuit for multiplexing signals of a plurality of line circuits multiplexed by the multiplex control circuit.
Channel groups are determined in advance for each subscriber line multiplexer.
Output to the first signal line
Output to the direction signal line, and to the input direction signal line of the first signal line
The second channel group of the input time-division multiplexed signal is
Channel conversion to convert to a channel group corresponding to the in circuit
Circuit, the first signal input to the input direction signal line of the second signal line
Multiplex the signal of the channel group with the output signal of the multiplex control circuit
And a time division multiplexed signal line output from the interface.
The signal of the second channel group is output to the output direction of the second signal line.
A multiplexing circuit for outputting to the signal line , wherein the output of the first signal line of the another subscriber line multiplexer is provided.
The direction signal line is a second signal line of the first subscriber line multiplexer.
Output line signal of the first subscriber line multiplexer connected to the input line signal line of the first line.
Line is a first signal line of the another subscriber line multiplexer.
A subscriber line multiplexer connected to an input direction signal line .