JP2862583B2 - Voice multiplexing equipment - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a voice multiplexing apparatus for multiplexing and transmitting voice signals in a packet format via a digital switching network.

(Conventional technology) In a conventional voice multiplexing device, a line for transmitting a voice packet signal uses a dedicated line, so the line is set even when there is no voice signal, and is applied to a communication system in which traffic fluctuation is large. In such a case, it was necessary to prepare the number of lines according to the traffic conditions at the time of the last connection.

(Problems to be Solved by the Invention) In order to solve the above problems, an object of the present invention is to use a switching network so that a line for transmitting a voice packet signal can be set as required, and a line can be set according to traffic. It is an object of the present invention to provide a voice multiplexing device capable of setting the number.

(Means for Solving the Problems) According to the present invention, an audio signal is converted into a packet format,
There are provided a plurality of packetizing circuits for creating a packet in which identification information is added to each packet format, and the packets created by these packetizing circuits are stored in a buffer circuit in the order in which they were created. Setting / release is instructed, and one of the plurality of network control circuits sets / releases a line according to the instruction. A transmission interface circuit is provided in one-to-one correspondence with the plurality of network control circuits, and each transmission interface circuit takes out packets in the order stored from the buffer circuit when the line is set, and sets the line according to the line speed. To send out. The control circuit instructs the setting / release of the line in accordance with the traffic, which counts the number of packets stored in the buffer circuit and uses the packet state stored in the buffer circuit as a control packet as a control packet. And instructs line setting / release according to the number of packets or the rate of change of both the packet status indicated by the control packet from the partner device and the packet status of its own buffer circuit. Alternatively, the connection request is received from the packetizing circuit, and the request is made according to the number of the connection requests or the rate of change thereof.

(Embodiment) FIG. 1 shows an embodiment of the present invention. A packetization circuit 12 for packetizing an audio signal is provided for each input / output line 11, and a packet from each packetization circuit 12 is stored in a common buffer circuit 13. The control circuit 14 monitors the packet state of the buffer circuit 13 and periodically generates a control packet indicating the packet storage state of the buffer circuit 13 and sends the control packet to the buffer circuit 13. The control packet includes, for example, a label indicating that the packet is a control packet, a command indicating that the content information is in the state of the buffer circuit, and content information indicating the state of the buffer circuit, as shown in FIG. The control circuit 14 monitors the state of the buffer circuit 13 and the state of the buffer circuit of the partner device notified by the control packet received from the distribution circuit 19, and instructs the setting / release of the switched line. A transmission interface circuit 16 is provided corresponding to each of the switching lines 15, and the transmission interface circuit 16 provides a buffer circuit 13 when the line is set.
, And sends it out to the switching line 15. The transmission interface circuit 16 takes out the packet stored in the buffer circuit 13 and sends out the control packet, when there is a control packet, to the switching line 15 with priority. A network control circuit 17 is provided for each transmission interface circuit 16,
The network control circuit 17 controls connection of the switching line 15 according to an instruction from the control circuit 14. Further, a reception interface circuit 18 for receiving a packet signal is connected to each switching line 15. The distribution circuit 19 distributes the received packet signal to the control circuit 14 based on the identification information in the packet signal, and distributes the voice packet to the decoding circuit 21 provided for each input / output line 11. The decoding circuit 21 restores the distributed packet signal to an audio signal.

The audio signal received from the input / output line 11 is converted into a packet having a format as shown in FIG.
13 is stored sequentially. Each audio packet includes a label indicating audio data, a line number for identifying the input / output line 11, identification information including time information indicating the time of packetization, and audio data. The buffer circuit 13 sequentially stores the output audio packets from the plurality of packetizing circuits 12 and the control packets from the control circuit 14, and gives priority to the control packets according to the read request from the transmission interface circuit 16, and the audio packets are given first. The stored packets are transmitted in order. The control circuit 14 monitors the number of packets stored in the buffer circuit 13 and the number of packets stored in the buffer circuit of the partner device notified by the control packet received from the distribution circuit 19, and stores them, for example, in both. If the sum of the number of packets exceeds a fixed value Xm or the rate of increase is large, the network control circuit 17 corresponding to the (m + 1) th switched line 15 is instructed to set the switched line. The transmission interface circuit 16 for which the line has been set by the network control circuit 17
Sends out the packet read from the buffer circuit 13 in accordance with the speed of the switching line. When the sum of the number of packets becomes smaller than a certain number Ym (Xm> Ym), the control circuit 14 instructs the network control circuit 17 to release the (m + 1) th switched line.

On the other hand, packets received from the switching line 15 are temporarily stored in the distribution circuit 19 via the reception interface circuit 18. The distribution circuit 19 identifies the output I / O line 11 or the control circuit 14 based on the identification information of each packet, the voice packet is sent to the corresponding decoding circuit 21, and the control packet is sent to the control circuit.
Distribute to 14. The decoding circuit 21 restores the packet received from the distribution circuit 19 to an audio signal and sends out the audio signal to the input / output line 11.

FIG. 3 is a diagram for explaining a system using an apparatus to which the present invention is applied. Audio multiplexing device to which the present invention is applied
22 and 23 are connected to a digital switching network 24. The voice multiplexing device 22 packetizes the voice signal transmitted from the input / output line 11 and multiplexes the voice signal to the switching line 15 for transmission.
The packet received from 15 is converted back to an audio signal and transmitted to the corresponding input / output line 11. Audio multiplexer 23 is an input / output line
The voice signal sent from the switch 25 is packetized and multiplexed to the switching line 26 for transmission, and the packet received from the switching line 26 is converted back to a voice signal and transmitted to the corresponding input / output line 25. The digital switching network 24 accommodates lines including the switching lines 15 and 26 and provides a connection service according to a request. The voice multiplexing devices 22 and 23 connect the switching line 15 and the switching line to the digital switching network 24 in accordance with the amount of the voice signal to be transferred.
Request to increase or decrease the number of connections with 26. For example, when there is no communication at all, the switching lines 15 and 26 are not connected at all. When the voice multiplexing device 22 requests a communication or detects a voice signal, it uses one of the switching lines 15 to make a request for connection to the digital multiplexing network 24 to the voice multiplexing device 23. A connection to one of the lines 26 is made. The voice signal of multiple communications is multiplexed and transmitted using this line. However, if the number of communication requests and voice signals increase further, the transfer capability becomes insufficient. Shortage can be avoided. In addition, if the number of communication requests and the number of voice signals are reduced, the transfer capability is left over, so one of the switching lines is disconnected. Therefore, the line can be effectively used in the digital switching network 24.

FIG. 5 shows a reference example relating to the present invention, and portions corresponding to FIG. 1 are denoted by the same reference numerals. The packetizing circuit 31 detects the communication request of the input / output line 11 and packetizes the audio signal, and supplies the communication request and the disconnection to the control circuit 32. The voice packet from the packetizing circuit 31 and the control packet from the control circuit 32 are stored in the buffer circuit 27. The control circuit 32 monitors the status of the packetization circuit 31, that is, the connection / disconnection request of the input / output line 11, and the status of the packetization circuit 31 of the partner device notified by the control packet received from the distribution circuit 29, and performs switching. Activate line setup / release. Further, the control circuit 32 periodically supplies the state of the packetizing circuit 31 to the buffer circuit 27 as a control packet.

In FIG. 5, the audio signal received from the input / output line 11 is converted into a format as shown in FIG. Store them sequentially. The buffer circuit 27 includes output voice packets from the plurality of packetizing circuits 31 and a control circuit.
The control packets from 32 are sequentially stored, and in accordance with the read request from the transmission interface circuit 16, the voice packets are transmitted in order from the previously stored voice packet, and the control packets are transmitted immediately. The control circuit 32 monitors the state of the packetization circuit 31 and the state of the packetization circuit of the partner device notified by the control packet received from the distribution circuit 29, for example, to determine the number of input / output lines requesting communication between the two. Sum is constant X _m
When the number exceeds the threshold or the rate of increase is large, the network control circuit 17 corresponding to the (m + 1) th switched line is instructed to set a switched line. The transmission interface circuit 16 of the switched line whose line is set in the digital network sends out the packet read from the buffer circuit 27 in accordance with the speed of the switched line 15. Further, the control circuit 32, for example, an instruction if the sum of the number of input and output lines to request communication is less than the predetermined value _{Y m (Y m <X m} ) the release of the (m + 1) th switching line to the network control circuit 17 I do. On the other hand, packets received from the switching line 15 are temporarily stored in the distribution circuit 29 via the reception interface circuit 18. The distribution circuit 29 identifies the output input / output line 11 or the control circuit 32 based on the identification information of each packet, and distributes the voice packet to the corresponding decoding circuit 21 and the control packet to the control circuit 32. The decoding circuit 21 restores the packet received from the distribution circuit 29 into an audio signal and sends out the audio signal to the input / output line 11. In FIG. 5, the setting / release of the switching line 15 may be performed by counting the number of input / output lines 11 requesting communication from the state of the packetizing circuit 31 without sending a control packet.

As described above, the present invention does not use a dedicated line, but shares a line in a switching network. Therefore, there is a possibility that an incoming call may be received from an unspecified number of people. In FIG. 5, in a receiving interface circuit 18 for detecting an incoming call from the other party's voice multiplexing device,
By analyzing the caller number transferred from the switching network when receiving a call, it is possible to reject a call from a device other than a specific voice multiplexing device.

(Effects of the Invention) As described above, according to the present invention, in the voice multiplexing apparatus, packet multiplex transmission is performed, and the number of switched lines is increased or decreased according to traffic conditions. it can.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention, FIG. 2 is a diagram showing an example of a format of a voice packet, FIG. 3 is a block diagram showing an example of a system using the device of the present invention, and FIG.
The figure shows a format example of a control packet, and FIG. 5 is a block diagram showing a reference example relating to the present invention.

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) H04L 12/56 JICST file (JOIS)

Claims (1)

(57) [Claims] 1. A plurality of packetizing circuits for converting an audio signal into a packet format and adding identification information to each packet format, and packets created by the plurality of packetizing circuits in the order of creation. A buffer circuit for storing, a means for counting the number of packets stored in the buffer circuit, and generating information on the number or a change rate thereof as a control packet; and receiving a packet via a switching line of a digital switching network. From the number of packets stored in the buffer circuit and the packet state indicated in the control packet received through the switching line of the digital switching network, the number of both packets or the rate of change thereof. A control circuit for instructing the setting / release of a line according to A plurality of network control circuit for constant / release, provided corresponding to the plurality of network control circuit 1-one,
And a plurality of transmission interface circuits for sending out the control packets and the packets extracted in the order stored from the buffer circuit to the switching line in accordance with the line speed when the switching line is set.