JP2928378B2 - Method of transmitting call connection information in digital switching system and digital switching device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for transmitting call control information in a digital exchange system suitable for use in a digital exchange accommodating a terminal such as a multifunctional telephone or a data combination terminal, and a digital communication method. It relates to an exchange device.

(Prior Art) As is well known, in a digital switching system, there is a type in which a plurality of terminals are accommodated in a switching unit via a subscriber line, and communication signals transmitted from these terminals are multiplexed and transmitted. In this case, the calling exchange adds the call control information of each terminal to the signal obtained by multiplexing the communication signal, and transmits the multiplexed signal via the digital multiplex transmission line.
In the called side exchange, call control information is extracted from the multiplexed transmission line, each terminal is controlled based on the call control information, and a communication signal demodulated from the multiplexed signal is transmitted to each terminal.

Conventionally, in such a digital switching system, for example, when a communication signal for 30 lines is transmitted through a digital multiplexed transmission line of 2.048 Mb / s, it is transmitted as a multiplexed signal of 8 frames per ms. One frame is assigned information of 32 time slots (TS), and each time slot has a transmission capacity of 8 bits. in this case,
A total of 30 bits of call control information of 5 bits each are allocated to 6 frames of the second to seventh frames of the multiplexed signal, and each 30 bits of call control information is allocated to each of these 30 bits by 1 bit. Call connection information was being transmitted.

(Problems to be Solved by the Invention) However, in the above-described conventional method for transmitting call connection information, only one bit of call connection information per 1 ms (8 frames) is transmitted to one line to perform call connection control. Yes, this was sufficient for controlling a single-function telephone, etc., but the amount of information was small to control a terminal such as a multifunctional telephone device, a data terminal device, etc. in recent years with advanced terminals,
There was a drawback that those functions could not be used effectively.

By the way, the call connection information is not always transmitted data, but is transmitted only when the call state changes or when the call management data is updated. Also, in the case of the above conventional example, even if 30 bits are allocated to 30 lines, usually only some of them are used, so in such a case, the information of the second to seventh frames is used. Many empty bits are transmitted in the time slot of the channel. Further, in cases other than the change and update of the call state, the corresponding bits in the call control information channel are hardly used. Therefore, the conventional method has a problem that the bit use efficiency in the call control information channel is extremely low.

The present invention overcomes the drawbacks of the prior art and can increase the amount of call connection information to be transmitted, thus effectively controlling a multi-function telephone, a data terminal, and the like. It is an object of the present invention to provide a call control information transmission method and a digital switching device in a digital switching system that can increase the bit usage efficiency of an information channel.

(Means for Solving the Problems) In order to solve the above-mentioned problems, the present invention multiplexes communication signals transmitted from a plurality of terminals and adds call connection information of each terminal to the multiplexed signals. In the method for transmitting call connection information in the digital switching system for transmitting
The call connection information is read separately for each block, and when each call connection information is read, a channel selection signal for identifying which terminal in the block the call connection information is generated is generated. , This channel selection signal
The multiplexed signal is transmitted together with the call connection information of the corresponding terminal at a predetermined position.

Also, the present invention provides a method for transmitting a communication signal transmitted from a plurality of terminals to each called terminal, from the multiplexed signal in which the communication signals of the plurality of terminals and the call connection information thereof are multiplexed. In a method for transmitting call connection information in a digital switching system in which connection information is extracted and transmitted to each terminal, call connection information extracted from a multiplexed signal is based on a channel selection signal multiplexed and transmitted together with the call connection information. , And are distributed to each terminal for each block and transmitted to the corresponding terminal.

Further, in the method for transmitting call connection information in the digital switching system according to the present invention, the call connection information of each terminal transmitted by the multiplexed signal includes a plurality of bits, and the information of the plurality of bits is used for each frame of the multiplexed signal. The channel selection signal indicating the output destination of the call connection information is inserted into predetermined bits allocated to each block in the predetermined time slot and transmitted, and assigned to each block in the multiplexed signal. A plurality of bits are assigned to a predetermined time slot of any one of the assigned frames and transmitted.

On the other hand, the present invention provides a communication path control means for multiplexing and distributing transmission signals transmitted from a plurality of terminals, and inserting call connection information of each terminal into a signal in which communication signals are multiplexed, or transmitting the signal. A digital exchange device comprising call connection information insertion / extraction means for extracting each call connection information from the multiplexed signal and central control means for controlling these units to perform call connection control. Reads the call connection information of each terminal transferred from the central control means for each block, and generates a channel selection signal for identifying which terminal is the call connection information for each block. Call connection information transmitting means for multiplexing and transmitting each channel selection signal together with the call connection information to the call connection information insertion / extraction means; And the call connection information based on the channel selection signal which is transmitted together with the call connection information, characterized in that it comprises a call connection information distribution means for transferring to the central control unit distributes in each block.

Further, the call control information sending means of this device selectively reads the call connection information for each terminal transferred from the central control means for each block, and generates a channel selection signal for the plurality of selection means. A plurality of channel selection signals generated by the means and multiplexing conversion means for multiplexing the respective call connection information to the call connection information insertion means and transmitting the multiplexed transmission information.

Further, the call connection information distributing means of this apparatus reads the call connection information and the channel selection signal serially transferred from the call connection information extracting means and distributes these signals in parallel for each block. And a plurality of selection means for distributing call connection information transmitted in parallel from the distribution conversion means to predetermined terminals in the block based on the channel selection signal.

The selection means in the call connection information sending means selectively inputs the call connection information of the predetermined terminal transferred from the central control unit, and an input means, and a storage means for storing the call connection information read by the input means. Selection signal generating means for identifying which terminal the call connection information stored in the storage means is the call connection information of, and generating the channel selection signal; and the call connection information and selection information stored in the storage means. Output means for transmitting the channel selection signal generated by the signal generation means to the multiplex conversion means in parallel.

Further, the selection means in the call connection information distribution means, input means for selectively reading the call connection information and the channel selection signal for each predetermined block, storage means for storing the call connection information read by this input means, Judgment means for judging the output destination of the call control information in the block based on the channel selection signal read in parallel with the call control information, and accumulating by the accumulation means at the output destination judged by the judgment means And output means for outputting the call connection information.

(Operation) According to the present invention, the digital exchange device on the calling side selectively reads the call connection information transferred from the central control means for each block, and the call control information is stored in any terminal. It generates a channel selection signal for identifying whether it is call control information, inserts this channel selection signal and call connection control information into a multiplexed signal and transmits the multiplexed signal. The call connection information is transmitted to each terminal based on the channel selection signal.

(Embodiment) Next, with reference to the accompanying drawings, an embodiment of a call control information transmission method and a digital exchange apparatus in a digital exchange system according to the present invention will be described in detail.

The digital exchange system in this embodiment will be described by taking as an example a case where digital exchanges 10 and 20 are connected via a digital multiplex transmission line 30, as shown in FIG.

The digital exchanges 10 and 20 in this embodiment respectively accommodate a plurality of terminals such as a multifunctional telephone and a data terminal via a subscriber transmission line 5.

These digital exchanges 10 and 20 can multiplex and transmit the signals of the subscriber terminals for 30 lines. Each of the digital exchanges 10 and 20 includes a communication channel control module (HW CNTM) 12. A plurality of subscriber lines 5 connected to terminals are accommodated in the communication path control module 12. The communication path control module 12 multiplexes communication signals such as communication signals and data signals transmitted from a plurality of terminals and sends the multiplexed signals to the highway 32, and also outputs a multiplexed signal input via the highway 32 to each subscriber. This is a communication path control circuit for distributing to lines. The highway 32 and the multiplex transmission line 30 are configured by an uplink communication line and a downlink communication line, respectively.

The digital exchanges 10 and 20 include a call control processing system, that is, a central processing module (CPM) 14, a central processing module interface (CPM INF) 16 (hereinafter, simply referred to as an interface), and a call control information transmitting unit 18. It is configured to include.

The central processing module 14 is connected to the communication path control module 12, and performs a call from its own terminal and a multiplex transmission path.
A call connection processing control circuit which controls the communication path control module 12 upon detecting an incoming call from the terminal 30 to cause connection of the communication path and to insert and extract call control information to be described later. The central processing module 14 includes a call connection information transmitting unit 18 which converts call control information into serial byte data via the interface 16 in call processing between the own terminal and the partner terminal.
To supply.

As shown in FIG. 2, the call connection information transmitting section 18 includes a call control information insertion / extraction circuit (I / D) 40, a multiplexing circuit 42, and a distribution circuit 44.

In this figure, a call connection information insertion / extraction circuit 40 is connected between a highway 32 and a multiplex transmission line 30, inserts call connection information into a multiplexed signal of an uplink communication line, and multiplexes a downlink communication line. This is a circuit for extracting call connection information from a signal. The call connection information insertion / extraction circuit 40 performs insertion / extraction at a predetermined timing under the control of the central control module 14.
The multiplexing circuit 42 is a call connection information sending circuit that supplies call connection information of a plurality of terminals transferred from the central control module 14 via the interface 16 to the call connection information insertion / extraction circuit 40 as serial data.

The multiplexing circuit 42 includes a plurality of, in this embodiment, four selection circuits (SEL SA to SEL SD) 402 to 408 and a multiplex conversion circuit (MUX) 410. Selection circuit (SEL) 4
02 to 408 are connected to the interface 16 respectively.
~ 8 input lines SD1 ~ SD7, SD8 ~ SD15, SD16 ~ SD22, SD23 ~
SD30, call connection information is read from these input lines as serial data, and call connection information SDA, SDB, SD in the order of FIFO (first-in first-out).
C and SDD are output to the multiplex conversion circuit 410 as serial data. At this time, the selection circuits 402 to 408 output 3-bit channel selection signals SSA1 to SSA3, SSB1 to SSB3, and SSC1 to SSC for identifying from which input line the call connection information is input.
3. It has a function of generating SSD1 to SSD3 and outputting these channel selection signals to the multiplexing conversion circuit 410 in parallel. The multiplexing conversion circuit 410 serially converts the serial data SDA to SDD output from the selection circuits 402 to 408 and the channel selection signals SSA1 to SSA3 to SSD1 to SSD3 of each data to the call connection information insertion and extraction circuit 40. Output. The above-mentioned input lines SD1 to SD7, SD8 to SD15, SD16 to SD22 and SD23 to SD3
0 constitutes one block.

The details of the selection circuits 402 to 408 will be described with reference to FIG. In this figure, a control circuit (CNT) 80 reads call connection information supplied through input lines SD1 to SD7 connected to an interface (ININF) 82 into a buffer memory (BUF) 84 and inputs the call connection information to the buffer memory (BUF) 84. Detects the numbers SD1 to SD7 and selects the 3-bit channel selection signal SSA1
To SSA3. This control circuit 80
The call connection information read into the buffer 84 is read out as serial data SDA in the order of FIFO, and is output via an output interface 86 together with parallel 3-bit selection signals SSA1, SSA2, and SSA3 indicating the input number.

Referring again to FIG. 2, the distribution circuit 44 distributes the call connection information serially input from the call connection information insertion / extraction circuit 40 at a predetermined timing to a predetermined output line based on a channel selection signal. It is.

The distribution circuit 44 includes a conversion circuit 420 and four selection circuits 4
22 to 428. The conversion circuit 420 reads the call connection information and the channel selection signal in synchronization with the extraction timing of the call connection information insertion / extraction circuit 40, and
The output is distributed to 422 to 428. The selection circuits 422 to 428 transmit the respective call connection information RDA to RDD to the channel selection signal RS.
This is a circuit for outputting to output lines RD1 to RD30 corresponding to the terminals based on A1-RSA3 to RSD1 to RSD3. As shown in FIG. 4, these selection circuits 422 to 428
Similarly to the selection circuit 44, the control circuit 90, the output interface 92, the buffer memory 94, and the input interface 96
And In this figure, the control circuit (CNT) 90
Reads the serial data RDA input to the input interface (IN INF) 96 into the buffer memory (BUF) 94,
Further, it is a circuit which reads the channel selection signals RSA1, RSA2, RSA3 to determine the output destination. The control circuit 90 reads the data read into the memory 94 as serial data RDA in FIFO order, and outputs the data to the output lines RD1 to RD7 determined based on the channel selection signal. Output line RD described above
1 to RD7, RD8 to RD15, RD16 to RD22, and RD23 to RD30 each constitute one block.

On the other hand, as shown in FIGS. 5 to 7, the multiplexed signal transmitted on the digital multiplexing transmission path 30 is transmitted with the respective signals allocated to the uplink multi-frame and the downlink multi-frame. As shown in FIG. 5, the 1 ms multi-frame is made up of 125 μs first to eighth frames, and each frame has an 8-bit time slot (TS0 to TS31). The time slot TS0 includes a synchronization bit and a fault monitoring bit for transferring the multiframe between the digital exchanges 10 and 20 via the digital multiplex transmission path 30, and the time slots TS1 to TS15 and TS17 to TS30.
Are respectively assigned to the communication signals and transmitted. The call connection information includes, in time slot TS16, outgoing calls, incoming calls, disconnections,
It is inserted as call control information such as the called party number displayed on the display of the terminal and the data of the incoming call during the call. The communication signal is multiplexed by the communication path control module 12 and transmitted as a multi-frame. In the case of reception, the communication signal is distributed from the multi-frame to the own terminal by the communication path control module 12 and transmitted. The call connection information is transferred from the central processing module 14 to the call connection information transmission unit 18 as serial byte data from the output lines SD1 to SD30 of the interface 16 and inserted into a multi-frame by the call connection transmission unit 18. Transmitted. More specifically, the call connection information is transmitted to the multiplexing circuit in the call connection information transmitting section 18.
In the 42 selection circuits 402 to 408, the input lines SD1 to SD7,
The data is input via SD8 to SD15, SD16 to SD22, and SD23 to SD30. The call connection information supplied from these input lines is
Are transferred to the multiplexing / conversion circuit 410 as serial data SDA, SDB, SDC, SDD. At this time, the selection circuits 402 to
At 408, 3-bit selection signals SSA1 to SSA3, SSB1 to SSB3, SSC1 to SSC3, and SSD1 to SSD3 indicating the input destination of the call connection information are generated and output to the multiplexing conversion circuit 410 in parallel.
The multiplex conversion circuit 410 includes call connection information SDA to SDD serially transferred from the selection circuits 402 to 408 and channel selection signals SSA1 to SSA3 to
SSD1-SSD3 time-division multiplexing and call connection information insertion and extraction circuit
Output serially to 40. The part 40 inserts this output into the time slot TS16 of the first to eighth frames of the multiframe shown in FIG. 5 in the format shown in FIG. 6 and outputs it to the digital multiplexing transmission line 30.

The call connection information insertion / extraction circuit receives the multiframe from the partner device 20 (10), and from the time slot TS16 of the first to eighth frames, the data RDA to RDD of FIG. 7 and the channel selection signal RSA1− of each data. RSA3 to RSD1−RSD3 are extracted and output to the distribution circuit 44 of the call connection information transmitting unit 18. Distribution circuit 44
Is the selection circuit corresponding to the channel selection signal group order
The output is distributed to 422 to 428. The selection circuits 422 to 428 transmit the call connection information RDA to RDD to their channel selection signals RSA1 to RSA3 to
Based on RSD1-RSD3, the signals are output to output lines RD1-RD30 corresponding to the respective terminals. The central processing module 14 reads this output via the interface 16 and controls the communication path control module 18. Call control module 18
Connects the receiving terminal according to the call control information, and transmits / receives the communication signal of the calling / receiving terminal via the multi-frame of the highway 32.

According to the call connection information transmission method in this embodiment, the call connection information transferred from the central control module 14 is read for each block by the plurality of selection circuits 402 to 408 of the call connection information transmission unit 18 and read. In this block, a channel selection signal for identifying which terminal is the call connection information is generated, and this channel selection signal is inserted into the multiplexed signal together with the call connection information and transmitted. The call connection information is transmitted except for the channels that do not exist, and in this embodiment, the call connection information can be transmitted eight times as much as the conventional one. Therefore, it is extremely advantageous in controlling a multifunctional telephone or a data combination terminal.

In the above embodiment, the digital exchanges 10, 20
Although the description has been made assuming that the exchange is a telephone exchange, the digital exchange 10 or 20 may be a private branch exchange, a remote line control device, or the like. Further, another relay station or the like may be interposed in the digital multiplex transmission line 30.

(Effects of the Invention) As described above, according to the present invention, the call connection information transferred from the central control means is read for each of a plurality of blocks, and each block is used to determine which terminal the call connection information is. Generate a channel selection signal for identification,
Since this channel selection signal is inserted into the multiplexed signal together with the call connection information and transmitted, the call connection information is transmitted except for the unused channels, and the transmission capability of the call control information is several times that of the conventional example. Can be increased. Therefore, a multifunctional terminal such as a multifunctional telephone and a data terminal can be sufficiently controlled. Further, by selectively multiplexing the call control data generated in a burst manner, an excellent effect that the call control information can be efficiently transmitted is achieved.

[Brief description of the drawings]

FIG. 1 is a system diagram showing an embodiment of a digital switching system to which a call control information transmission method and a digital switching device according to the present invention are applied. FIG. 2 is a functional block diagram showing a main part in the embodiment. Is a functional block diagram showing the configuration of the transmission cell selector of FIG. 2, FIG. 4 is a functional block diagram showing the configuration of the reception selector of FIG. 2, and FIG. 5 is a signal showing the configuration of a multiplexed signal in the embodiment. FIG. 6 is a signal configuration diagram showing, on the transmission side, an allocation state of call control information and a channel selection signal in the embodiment. FIG. 7 is a diagram showing an allocation state of the call control information and the channel selection signal in the embodiment. It is a signal block diagram shown by the side. Description of Signs of Main Parts 10, 20 Digital Switch 12 Communication Control Module 14 Central Processing Module 16 Central Processing Module Interface 18 Call Connection Information Transmission Section 30 Digital Multiplex Transmission Line 40 …… Call connection information insertion / extraction circuit 42 …… Multiplexing circuit 44 …… Distribution circuit

Claims (7)

(57) [Claims] 1. A multiplexed signal to be transmitted includes a plurality of predetermined frames in a predetermined period, each frame including a plurality of predetermined time slots, each of which includes a predetermined plurality of bits. A digital switching system for multiplexing communication signals transmitted from a plurality of terminals by inserting the communication signals into predetermined time slots of the respective frames, and adding call connection information of each terminal to the multiplexed signals for transmission. The method for transmitting call connection information according to claim 1, wherein the plurality of terminals are divided such that one block includes a plurality of predetermined terminals, and the plurality of terminals are divided into a plurality of predetermined blocks. Setting the number obtained by adding the number of identification bits of the predetermined plurality of terminals of each block to the number of bits of the one time slot or a number smaller than the number of bits, Reading the connection information for each of the blocks, and generating a channel selection signal for identifying which terminal in the block the call connection information is at the time of reading each call connection information. And transmitting the channel selection signal together with the call connection information of the corresponding terminal to the same predetermined one time slot of each of the frames, and transmitting the multiplexed signal. The call connection information of
The same one of the same one time slot of each said frame
A plurality of bits obtained by adding one bit to the plurality of frames, or a plurality of bits smaller than the plurality of bits, and the information of the plurality of bits is allocated to each frame of the multiplexed signal for each block in their predetermined time slots. The channel selection signal indicating the output destination of the call connection information is inserted into predetermined bits and transmitted.
A method for transmitting call connection information in a digital switching system, wherein a plurality of bits are allocated and transmitted to a predetermined time slot of any one of the frames allocated to each block in a multiplexed signal. 2. When transmitting communication signals transmitted from a plurality of terminals to respective called terminals, each communication signal of the plurality of terminals and its call connection information are multiplexed from a multiplexed signal to multiplex each call. A method for transmitting call connection information in a digital switching system in which connection information is extracted and distributed to each terminal, comprising: a step of receiving a multiplexed signal formed and transmitted by the method according to claim 1 as the multiplexed signal; The call connection information extracted from the multiplexed signal, based on the channel selection signal multiplexed and transmitted together with the call connection information, and distributed to each terminal for each block. Call connection information transmission method. 3. A communication path control means for multiplexing and distributing communication signals transmitted from a plurality of terminals, and inserting call connection information of each terminal into a signal multiplexed with the communication signals,
Or a digital switching device comprising call connection information insertion and extraction means for extracting each call connection information from the transmitted multiplexed signal, and central control means for controlling these units to perform call connection control, The multiplex signal is configured to include a plurality of predetermined frames in a predetermined period, each of the frames includes a predetermined plurality of time slots, each of the time slots includes a predetermined plurality of bits, The communication signal transmitted from is inserted into a predetermined time slot of each frame and multiplexed, and the apparatus reads the call connection information of each terminal transferred from the central control means for each block, A channel selection signal for identifying which terminal is the call connection information for each block is generated, and each channel selection signal is generated. A call connection information transmitting unit for multiplexing and transmitting the call connection information together with the connection information to the call connection information insertion / extraction unit, wherein each of the blocks divides the plurality of terminals such that one block includes a plurality of predetermined terminals. The plurality of terminals are obtained by dividing the plurality of terminals into a plurality of predetermined blocks,
The number obtained by adding the predetermined plurality of block numbers and the predetermined plurality of terminal identification bits of each block is set to the number of bits of the one time slot or a smaller number. Further, the call connection information extracted by the call connection information insertion / extraction means is distributed in each block based on a channel selection signal transmitted together with the call connection information and transferred to the central control means. Information distributing means, the call connection information of each terminal transmitted by the multiplexed signal,
The same one of the same one time slot of each said frame
A plurality of bits obtained by adding one bit for the plurality of frames, or a plurality of bits smaller than the plurality of bits, and the information of the plurality of beats is allocated to each frame of the multiplexed signal for each block in the predetermined time slot. The channel selection signal indicating the output destination of the call connection information is inserted into predetermined bits and transmitted.
A digital switching device, wherein a plurality of beats are assigned and transmitted to a predetermined time slot of any one of the frames assigned to each block in a multiplexed signal. 4. The digital switching system according to claim 3, wherein said call control information sending means selectively reads call connection information for each terminal transferred from said central control means for each block, A plurality of selection means for generating a selection signal; a plurality of channel selection signals generated by the selection means;
A multiplex conversion means for multiplexing each piece of call connection information to the call connection information insertion means and transmitting the multiplexed information. 5. The digital exchange according to claim 3, wherein said call connection information distribution means reads call connection information and a channel selection signal serially transferred from said call connection information extraction means, and converts these signals. Distribution conversion means for transmitting in parallel for each block, and a plurality of selection means for distributing call connection information transmitted in parallel from the distribution conversion means to predetermined terminals in the block based on the channel selection signal. A digital exchange device characterized by the above-mentioned. 6. A digital exchange according to claim 4, wherein said selection means in said call connection information sending means selectively reads the call connection information of a predetermined terminal transferred from said central control unit and said input means. Storing means for storing the call connection information read by the input means; identifying which terminal the call connection information stored in the storage means is the call connection information; and generating the channel selection signal. Selection signal generation means, and output means for transmitting the call connection information stored in the storage means and the channel selection signal generated by the selection signal generation means to the multiplex switching means in parallel. And a digital exchange device. 7. The digital exchange according to claim 5, wherein said selection means in said call connection information distribution means selectively inputs call connection information and a channel selection signal for each predetermined block; Storing means for storing the call connection information read by the means; determining means for determining an output destination of the call control information in the block based on the channel selection signal read in parallel with the call control information; Output means for outputting the call connection information stored in the storage means to the output destination determined in (1).