JPH01251893A - Control information transmission system for subscriber concentrator - Google Patents

Abstract

PURPOSE:To concentrate-multiplex without wasting a channel by disusing the signaling bit of a digital multiplex line for a direct control information transmission, using the specification of a control information transmission route and transmitting much control information with the separate use of a communication circuit. CONSTITUTION:One of arbitrary idle channels is selected from an exchange control part for a concentrator interface 2 to be installed in an exchange based on a concentration switch control information and a means to inform a concentrator 3 of using the channel for the control information transmission with the use of one bit of the signaling bits on the digital multiplex line 4 which the channel owns is provided. A means to supervise one bit of the signaling bits of each channel and to identify a channel for the control information transmission is provided on the concentrator 3. Thus, the transmission of the control information can be executed by using the channel, at the time of the transmission of the control information, the signaling bit of the digital multiplex line is used for the specification of the control information transmission route and much control information can be transmitted with the use of the separate communication circuit.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a subscriber concentrator control information transmission system, and in particular to a system for concentrating and multiplexing distant subscriber groups and connecting them to a switching center using digital multiplex lines. This invention relates to a control information transmission method for a line concentrator.

[Conventional technology]

Conventionally, in this type of line concentrator, control information for the line concentration switch is transmitted by the following method.

In other words, since there are few signaling bits on the digital multiplex line, it is necessary to deconcentrate the line, or to destroy one channel, that is, to transmit one channel as a dedicated channel for transmitting control information, or to secure enough bits. It has a long framing composition.

[Problem to be solved by the invention]

However, among the conventional subscriber line concentrators mentioned above, the non-concentrator type is uneconomical due to its low channel usage efficiency, and the one that destroys one channel limits the line concentration and furthermore The method based on framing has the drawbacks of being vulnerable to disturbances and not being able to use high-order multiplex lines.

SUMMARY OF THE INVENTION An object of the present invention is to provide a subscriber line concentrator control information transmission system that eliminates the above-mentioned drawbacks and allows line concentrator multiplexing without wasting channels, especially even in a small capacity line concentrator. be.

[Means to solve the problem]

The present invention is a subscriber line concentrator control information transmission method in a subscriber line concentrator that concentrates and multiplexes a group of distant subscribers and accommodates them in a switching center using digital multiplex lines. selects one of the empty channels based on the concentrator switch information G from the exchange control unit, and uses that channel for control information transmission using one signaling bit on the digital multiplex line of that channel. The VA concentrator includes means for notifying the concentrator that the control information transmission channel is to be transmitted, and the concentrator includes means for monitoring the bits of the signaling bits of each channel to identify the control information transmission channel.

〔Example〕

Next, the present invention will be explained with reference to the drawings.

FIG. 1 shows the configuration of an embodiment of the subscriber concentrator control information transmission system of the present invention, FIG. 2 is a configuration diagram of an example of the concentrator interface of FIG. 1, and FIG. FIG. 2 is a configuration diagram of an example of a line concentrator.

As shown in FIG. 1, this system is a subscriber concentrator that concentrates and multiplexes a group of distant subscribers and accommodates them in a switching center using digital multiplex lines. Connected via 4.

That is, a line concentrator 3 in which a part of the subscriber line concentrator stage of the exchange is carried out to a distant place accommodates subscriber telephones 5 to 5, and connects the subscriber telephones 5 to 5 to the exchange apparatus 1 through the concentrator interface 2 via the digital multiplex line 4. It is accommodated.

The concentrator interface 2, as shown in FIG.
Control unit 201, communication circuits 202 and 203, and gate 2
04, selector 205, time switch 206,
It includes a control memory 207, a multiplexing/demultiplexing circuit 208, a digital multiplex line control section 209, and digital multiplex line interfaces 210 to 211.

The control unit 201 is a control unit of the line concentrator interface 2, receives control information from the control unit of the switching center 1 through the communication circuit 202, relays it to the line concentrator 3, and performs digital multiplexing based on the information. The usage status on line 4 is understood.

The communication circuit 203 is a communication circuit that transmits control information to the line concentrator 3, and is used by being connected to an arbitrary channel on the digital multiplex line 4 by a time switch 206. The selector 205 connects the specific channel to be used with the communication circuit 203 without transmitting it to the exchange. The gate 204 is for concentrating lines according to instructions from the time switch 206 and the exchange control unit, and connects or disconnects channels on the assigned concentrator bus. The control memory 207 is a control memory that controls the time switch 206 and the gate 204, and the multiplex/demultiplex circuit 208 multiplexes a plurality of digital multiplex lines including the digital multiplex line 4 from the line concentrator 3, The digital multiplex line control unit 209 controls and monitors the digital multiplex line interfaces 210 to 211, and extracts, sends, and holds signaling bits. , holds the final state of all subscribers accommodated in the line concentrator 3, and periodically sends it to the exchange control unit.

As shown in FIG. 3, the line concentrator 3 includes a control section 301,
Digital multiplex line control section 302, digital multiplex line interface 303, and multiplex/demultiplex circuit 30
4.309, time switch 305, and control memory 3
06, selector 307, communication circuit 308, subscriber circuit control section 310, subscriber circuits 311 to 312,
A digital tone (reorder tone) generation circuit 313 is provided.

The control unit 301 is a control unit of the line concentrator 3, and controls the control information sent from the line concentrator interface 2 using any one channel of the digital multiplex line 4 through the time switch 305, selector 307, and communication circuit 308. subscriber control circuit 31 that receives and controls the line concentrator, as well as monitors and controls subscriber circuits 311 to 312;
Upon receiving the subscriber state change information from 0, the subscriber connects the digital multiplex line.

When the upper channel is not assigned, the control information transmission channel is used to report to the acquisition device interface 2. The digital multiplex line control unit 302 controls and monitors the digital multiplex line interface 303, and extracts, sends, and holds signaling bits. Further, the control memory 306 includes the time switch 30
The time switch 305 is controlled by an instruction from the control unit 301 to connect an arbitrary subscriber to an assigned channel on the digital multiplex line 4.

Further, a digital multiplex line interface 303,
The digital tone generation circuit 313 is connected to the multiplex/demultiplex circuit 304, and further connected to the subscriber circuits 311 to 31.
The multiplexing/demultiplexing circuit 309 to which 2 is connected can be selectively switched to the communication circuit 308 by the selector 307.

In this system, the signaling bits on the digital multiplex line 4 in the direction from the switching center to the concentrator 3 are not used for direct control information transmission, but are used as voice pulses based on the concentrator switch control information from the switching center control section. The line concentrator interface 2 on the exchange side has means for notifying the line concentrator 3 that the channel is used for control information transmission by using one bit of the signaling bit of any channel that is not used for control information transmission, and the line concentrator 3 has a means of selecting the channel by monitoring the signaling bits, and both parties can transmit control information by connecting a communication circuit using a high-speed heritator link control device +11' ((HDLC) etc. to the channel. The operation thereof will be explained below.

The control unit 201 of the concentrator interface 2 constantly monitors the usage status on the digital multiplex line 4 based on control information from the exchange control unit and maintains the status. For example, when a subscriber makes a call, the subscriber control circuit 310 detects the change, and the control unit 30 of the line concentrator 3
1 using the communication circuit 308, it reaches the control unit 201 of the line concentrator 2 via the communication circuit 203, and is written into the corresponding subscriber state memory of the digital multiplex line control unit 209, so that it can be transmitted periodically. The information is sent to the exchange control unit and reported. The exchange control section is
If this is recognized, it is regarded as a call, one of the vacant channels on the digital multiplex line 4 is assigned to that subscriber, and line concentration control information is sent out to connect the subscriber. The control unit 201 of the line concentrator interface 2 receives this and sends it to the line concentrator 3 using the communication circuit 203, and if there is a confirmation answer, sets the state corresponding to that channel to be in use and controls the time switch 206. Create a bus.

One of the empty channels is determined based on the usage status of the channel created in this way, and in order to notify the line concentrator 3 that the channel will be used for control information transmission, one of the signaling bits of that channel is set.
The digital multiplex line controller 209 is instructed to set one channel, and the communication circuit 203 is connected to that channel.

If control information for allocating a channel in use arrives, it searches for another empty channel and rewrites the signaling bits. On the other hand, the control unit 301 of the line concentrator 3 constantly monitors the signaling bit and controls the communication circuit 308 to be connected to the set channel.

During a call, there is no control other than billing control, so all channels are used and there is no problem even if control information transmission is no longer performed, so the control unit 201 of the concentrator interface 2 sets the last channel. After checking the information, send a disconnect and temporarily stop the call. The status of the subscriber during the call is sent from the subscriber circuit control unit 310 to the digital multiplex line control unit 302 regardless of the control information transmission method described above, and is sent by the signaling bit of the channel being used, so disconnection is not necessary. When the channel release control information is transmitted to the exchange control unit via the concentrator interface 2, the control unit 201 of the concentrator interface 2 sets the channel status as empty and sets the signaling bit to set up the control channel. The control fffll information is transmitted to the line concentrator 3. Note that when a billing signal is required, since there are two or more signaling bits per channel on the digital multiplex line 4, transmission can be stopped using other bits.

Furthermore, since nothing can be done to the subscriber who made the call when all channels are in use, the control unit 301 of the line concentrator 3 does not notify the subscriber and calls the subscriber to the digital tone (reorder tone) generation circuit 313. The time switch 305 is controlled to connect to.

As mentioned above, in a subscriber line concentrator that concentrates and multiplexes a group of distant subscribers and accommodates them in a switching center using digital multiplex lines, the line concentrator interface 2 installed in the switching center receives line concentration switch control from the switching center control unit. Means for selecting one of the empty channels based on the information and using one bit of the signaling bit on the digital multiplex line 4 of that channel to inform the line concentrator 3 that the channel will be used for control information transmission. and a line concentrator 3
is one of the signaling bits of each channel.
By providing a means for monitoring focus and identifying a control information transmission channel, control information can be transmitted using that channel, and when transmitting control information, the signaling bits of the digital multiplex line can be directly It is not used to transmit control information, but is used to determine the control information transmission route, and a separate communication circuit can be used to transmit a large amount of control information.

〔Effect of the invention〕

As explained above, according to the present invention, the signaling bits of the digital multiplex line are not used directly to transmit control information, but are used to specify the control information transmission route, and a separate communication circuit is used to transmit a large amount of control information. By enabling transmission, especially in a small-capacity acquisition device, line concentration and multiplexing can be performed without wasting channels, resulting in more economical line concentration.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an example of the subscriber line concentrator control information transmission method of the present invention, FIG. 2 is a block diagram showing an example of the subscriber line concentrator interface of FIG. 1, and FIG. 1 is a configuration diagram showing an example of the following. 1...Switching center device 2...Concentrator interface 3...Concentrator 4...Digital multiplex lines 51 to 57... Subscriber telephone 201... Control units 202, 203... Communication circuit 204... Gate 205... Selector 206... Time switch 207... Control memory 208... Multiplexing... Demultiplexing circuit 209 ... digital multiplex line control section 210 ~
211...Digital multiple line interface 301...Control unit 302...Digital multiple line control unit 303
...Digital multiplex line interfaces 304, 309...Multiplex/demultiplex circuit 305...
...Time switch 306 ...Control memory 307 ...Selector 308 ...Communication circuit 310 ...Subscriber circuit control section 311-312 ...Subscriber circuit 313 ...Digital tone generation circuit agent
Patent Attorney Yoshiyuki Iwasa 1 - - Switching center equipment 2 - Concentrator interface 3 - Concentrator 4 - Digital triple diagram lines 51 to 5o - Subscriber telephone No. 1 Figure 201---Kaikai Iku 202, 203...--Tsuniyon C Roro each. 204 --- Gate 205 --- Selector 206 --- Times inch 207 --- Control memory 208 --- Multiplex/demultiplex circuit 209 --- Digital multiplex line To control unit 210 2
11.--Digital multiple line interface 2nd
figure

Claims (1)

[Claims] (1) A subscriber line concentrator control information transmission method in a subscriber line concentrator that concentrates and multiplexes a group of distant subscribers and accommodates them in a switching center using digital multiplex lines. , select any empty channel from the exchange control unit based on the concentrator switch information, and use that channel for control information transmission by using one bit of the signaling bit on the digital multiplex line that that channel has. subscriber line concentrator control information, characterized in that the line concentrator includes means for notifying the line concentrator of the information, and the line concentrator includes means for monitoring the bits of the signaling bits of each channel to identify a control information transmission channel. Transmission method.