JPS6336719B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a fixed line accommodating system, and more particularly to a fixed line accommodating system, which comprises a plurality of digital terminal units and a multiplexing device, each accommodating a plurality of communication channels for transmitting voice signals and control signals, and a voice separation format. The present invention relates to a fixed line accommodating system in digital terminal equipment that configures a digital multiplex communication path including a control signal path.

FIG. 1 is a diagram showing an example of a connection between a conventional digital terminal device of this type and a time division switch. In FIG. 1, the digital terminal equipment DT is composed of five sets of digital terminal units DTU0 to DTU4 and a multiplexer MPX. Each of the digital terminal units DTU0 to DTU4 accommodates a channel group CHG0 to CHG4, each including 24 channels CH for transmitting a voice signal V and a control signal S such as a hooking signal. Each channel group CHG
CHG 0 to CHG 4 are time-division communication paths having a frame structure as illustrated in FIG. In FIG. 2, each frame F (CHG), which is repeated at a period of 125 microseconds as is well known, consists of a 1-bit synchronization bit Fb and 24 time slots TS each consisting of 8 bits. Each time slot TS is assigned to 24 channels CH,
Normally all 8 bits are used for transmitting the audio signal V. In addition, each time slot TS is set every 6 frames.
Bit b7 is used for transmitting the control signal S of the corresponding channel CH. Note that the control signal S requires a maximum of 2 bits, so the control signal S requires 12 frames (1.5
It is transmitted with a period of milliseconds). The communication path groups CHG0 to CHG4 as described above are connected to the multiplexer via the digital terminal units DTU0 to DTU4.
A digital multiplex channel HW including 120 channels CH is configured based on the MPX. The digital multiplex communication path HW has a frame structure as illustrated in FIG. In FIG. 3, each frame F(HW), which is repeated every 125 microseconds, consists of 128 time slots TS, each consisting of 8 bits. Of these, time slots TS4 to TS63 and time slots TS68 to 12
7 are respectively assigned to 120 communication paths CH, and all 8 bits are used for transmitting the audio signal V (hereinafter, each time slot TS will be referred to as an audio signal path VCH). Also, time slots TS64 and TS65 are
The control signal S for 120 communication channels CH is 16 frames (2
The time slots TS64 and TS65 are hereinafter referred to as the control signal path SHW. The digital multiplexed communication paths HW as described above are connected to the time division network TD-NW of the time division exchange, and each communication path CH is connected to a required subscriber SUB etc. under the control of the central controller CC. Note that the central controller CC uses a digital multiplex communication path for the connection control.
The control signal path is
Extracts SHW and sends and receives control signal S. Furthermore, in controlling the subscriber SUB, control signals S are sent and received between the subscriber circuit LC and the corresponding subscriber circuit LC, as is well known.

As is clear from the above explanation, the conventional digital terminal equipment DT is connected to the time division exchange through a digital multiplex communication path HW having a frame structure as shown in FIG. 3, and control signals transmitted through the control signal path SHW. S is always transmitted to the subscriber circuit LC via the central control unit CC. Therefore, it becomes impossible to apply a so-called fixed line service in which a specific communication channel CH is fixedly connected to a specific subscriber SUB or the like and placed outside the control of the central controller CC. As a countermeasure for this, each channel has been
Two audio signal paths VCH are assigned per CH, and the time division network TD-NW is also connected to the desired subscriber circuit LC via two audio signal paths, and the audio signal V is transmitted through one audio signal path VCH. However, measures have also been taken such as directly transmitting the control signal S to the subscriber circuit LC through the other voice signal path VCH. The channel CH accommodation capacity will be halved, which will impair the economic efficiency of the digital terminal equipment DT.

An object of the present invention is to eliminate the drawbacks of the conventional digital terminal equipment as described above, and to realize means capable of accommodating the fixed line without impairing economic efficiency.

This purpose consists of a plurality of digital terminal units and a multiplexer, each accommodating a plurality of channels for transmitting voice signals and control signals, and connects to a time division network via the digital multiplex channel. A digital terminal device that transmits and receives voice signals and control signals between the multiplexing device and the time-division network includes an extraction circuit that extracts voice signals and control signals from a digital multiplex communication path from the multiplexing device to the time-division network; an insertion circuit for inserting a control signal into a digital multiplexed communication path from the workpiece to the multiplexing device, and a control signal corresponding to an arbitrary communication path channel from among the audio signals and control signals sent from the extraction circuit; a first memory that takes out the control signal and sends it to the multiplexing device; a second memory that allocates the control signal sent from the multiplexer via the control signal communication path to a corresponding communication channel, takes it out, and sends it to the insertion circuit; This is achieved by replacing one of the plurality of digital end station units with a control signal unit consisting of:

An embodiment of the present invention will be described below with reference to FIGS. 4 and 5. FIG. 4 is a diagram showing a fixed line accommodation system according to an embodiment of the present invention, and FIG. 5 is a diagram showing an example of the configuration of the digital terminal equipment in FIG. 4. Note that the same reference numerals indicate the same objects throughout the figures. In Figure 4, the digital terminal equipment
DT' is a digital terminal unit that accommodates communication path groups CHG0 to CHG3 consisting of 24 communication paths CH.
Four sets of DTU0 to DTU3 are provided, and a control signal unit SGU is connected to the multiplexer MPX in place of the digital terminal unit DTU4 in FIG. Although the control signal unit SGU does not accommodate the channel group CHG like the other digital terminal units DTU0 to DTU3, it does not accommodate the communication path group CHG to the multiplexer MPX under the same connection conditions as the digital terminal units DTU0 to DTU3. , 24 communication paths CH (hereinafter referred to as control signal communication path group SCHG) can transmit and receive audio signals V and control signals S. Therefore, the multiplexer MPX has a group of communication paths for the control signals.
A digital multiplex channel HW with a capacity of 120 channels as shown in FIG. 3 including SCHG is assembled.
In addition, the control signal path of the digital multiplex communication path HW
SHW is connected to the control signal unit SGU as shown in more detail in FIG. In FIG. 5, the digital multiplex channel HW assembled by the multiplexer MPX is shown in each transmission direction by a transmit multiplex channel HWS and a receive multiplex channel HWR, and the multiplex device MPX and the control signal unit
Control signal communication path group established between SGU
SCHG is shown for each transmission direction. The control signal path SHW included in the transmission multiplexed communication path HWS runs from point B to the memory RAM in the control signal unit SGU.
2, and by the write instruction signal W2, 120
Select any communication path from the control signal S for the communication path CH.
A control signal S corresponding to CH can be stored. The memory RAM2 has a storage capacity of 24 words (8 bits per word), and is read out from the digital terminal unit DTU0 by the read instruction signal R2 from the counting circuit CTR.
Under the same conditions as DTU3 to DTU3, the stored contents are sent to the multiplexer MPX at a rate of one word per channel CH.
The memory RAM1 also has a storage capacity of 24 words (8 bits per word), and is written to the digital terminal unit DTU0 by the write instruction signal W1 from the counting circuit CTR.
Under the same conditions as DTU3, the control signal channel group SCHG signal transmitted from the multiplexer MPX is
It is stored at a rate of one word per channel CH. The stored contents are extracted at any time by the read instruction signal R1, and sent to the reception multiplexing channel HWR via the insertion circuit I.
It can be inserted as a control signal S corresponding to any channel CH among the control signals S for 120 channels CH transmitted by the voice separation format control signal channel SHW included in the control signal channel SHW. The write instruction signal W2 and the read instruction signal R1 are generated from the central control unit CC of the time division switch via the control signal path SHW in the receiving multiplex communication path HWR and the multiplexer MPX to the control signal unit SGU. and the control circuit CTL
is determined by fixed line assignment data stored in memory RAM0. If none of the 96 communication paths CH included in communication path groups CHG0 to CHG3 are currently used as fixed lines, no fixed line allocation data will be transmitted, so the transmission multiplexed communication path
The control signal S corresponding to any communication path included in the control signal path SHW in HWS is not stored in the memory RAM2, and the control signal S in the reception multiplex communication path HWR is not stored in the memory RAM2.
The control signal S extracted from the memory RAM 1 is never inserted into SHW. Next, the communication path group
When using any of the 96 communication channels CH included in CHG0 to CHG3 as a fixed line FCH, at the beginning of use, the control signal unit SGU is sent from the central control unit CC of the time division exchange via the above-mentioned route. The fixed line allocation data is transmitted to the control circuit CTL of. The fixed line allocation data includes fixed line communication path FCH and control signal communication path group SCHG.
(hereinafter referred to as control signal communication path)
SCH). The fixed line allocation data is stored in memory RAM0, and memory RAM
Write instruction signal W2 for 2 and memory RAM
1 is transmitted through the control signal path SHW in the sending multiplexing path HWS and the receiving multiplexing path HWR.
The control signal S compatible with FCH is transmitted through the control signal communication path.
Generate as transmitted to SCH. As a result, the voice signal V of the fixed line communication path FCH is divided into the transmission multiplex communication path HWS and the reception multiplex communication path HWS, as is well known.
The control signal S of the fixed line communication path FCH is transmitted to the time division exchange by the voice signal path VCH unique to the HWR, and the control signal S of the fixed line communication path FCH is transmitted to the time division exchange by the voice signal path VCH unique to the control signal communication path SCH. On the other hand, in a time-division switch, when the central controller CC sends fixed line allocation data to the digital terminal equipment DT', the fixed line channel FCH and the control signal channel in the digital multiplex channel HW are
A voice signal path VCH unique to each SCH is fixedly connected to two voice signal path terminals of a subscriber circuit FLC targeted for fixed line service via the time division network TD-NW, and thereafter the fixed connection is made. are excluded from management. As a result, the fixed line communication path
The FCH control signal S is transmitted directly to the fixed line subscriber circuit FLC via the voice signal path VCH specific to the control signal communication path SCH and the voice signal path in the time division network TD-NW fixedly connected to this. transmitted to. Furthermore, when canceling the fixed line service in progress, the central controller CC transmits the fixed line cancellation data to the control circuit CTL in the control signal unit SGU via the same route as the fixed line allocation data, and also transmits the fixed line cancellation data to the control circuit CTL in the control signal unit SGU. Release the fixed connection set within the TD-NW. The control circuit CTL stores data in memory based on the received fixed line release data.
The fixed line assignment data stored in RAM0 is deleted, and the sending of the write instruction signal W2 and read instruction signal R1 is stopped. As a result, transmission of the control signal S corresponding to the fixed line communication path FCH extracted from the control signal path SHW is stopped by the control signal communication path SCH, and the fixed line communication FCH returns to the general communication path CH state. , and the control signal channel SCH can be used for other fixed connections.

As is clear from the above explanation, according to this embodiment, 24 channels CH out of 120 channels CH that can be accommodated by the digital terminal device DT′ are used as control signal channels.
By simply converting it to SCH, any channel CH out of 96 channels can be used as a fixed line channel up to 24 channels.
Can be used as FCH.

It should be noted that FIGS. 4 and 5 are only one embodiment of the present invention, and may be used, for example, in a digital terminal equipment.
The number of communication paths accommodated in DT', digital terminal unit DTU, and control signal unit SGU is not limited, and many other modifications may be considered, but the effects of the present invention will not change in any case. do not have. Also, channel group CHG and digital multiplex channel
The frame structure of the HW is not limited to that shown in FIGS. 2 and 3, and the effects of the present invention remain the same even in the case of other frame structures.

As described above, according to the present invention, fixed line services can be introduced without significantly reducing the communication path capacity of the digital terminal equipment.

[Brief explanation of drawings]

Fig. 1 is a diagram showing an example of the connection between a conventional digital terminal equipment and a time division electronic exchange, Fig. 2 is a diagram illustrating the frame structure of a group of communication paths, and Fig. 3 is a diagram showing the frame structure of a digital multiplex communication path. A diagram illustrating,
FIG. 4 is a diagram showing a fixed line accommodation system according to an embodiment of the present invention, and FIG. 5 is a diagram showing an example of the configuration of the digital terminal equipment in FIG. 4. In the figure, DT and DT' are digital terminal equipment, DTU0 to DTU4 are digital terminal units, SGU is a control signal unit, MPX is a multiplexer, TD-NW is a time division network, SUB is a subscriber, and LC is a Subscriber circuit, FLC is subscriber circuit for fixed line, DI is add-drop circuit, CC is central control unit, HW is digital multiplex communication path, CHG0 to CHG4 are communication path group, I is insertion circuit, RAM0,
RAM1 and RAM2 are memories, CTL is a control circuit,
CTR is a counting circuit, W1 and W2 are write instruction signals, R1 and R2 are read instruction signals, SCHG control signal communication path group, F is a frame, Fb is a synchronization bit, TS is a time slot, CH is a communication path, and V is the audio signal, S is the control signal, VCH is the audio signal path,
SHW indicates a control signal path.

Claims (1)

[Scope of Claims] 1. Consisting of a plurality of digital terminal units and a multiplexing device each accommodating a plurality of communication paths for transmitting audio signals and control signals, a time-division network is transmitted via the digital multiplex communication paths. A digital terminal device that transmits and receives audio signals and control signals to and from a workpiece, an extraction circuit that extracts audio signals and control signals from a digital multiplex communication path from the multiplexing device to the time division network; an insertion circuit for inserting a control signal into a digital multiplexed communication path from the time division network to the multiplexing device, and corresponds to any communication path channel from among the audio signals and control signals sent from the extraction circuit. a first memory for extracting control signals sent from the multiplexer to the multiplexing device; 1. A fixed line accommodating system characterized in that a control signal unit consisting of two memories is provided in place of one of the plurality of digital terminal units.