JPS6222494B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a message voice recording device in a switching network that employs a digital voice packet system.

Conventionally, messages in a telephone exchange network when the other party is busy or absent have been realized by an automatic recording device attached to the incoming telephone or by a voice recording device attached to the exchange itself. This recording device records audio on magnetic tape.
If a large number of messages are recorded, whether by a voice recording device attached to the telephone set or a voice recording device attached to the exchange itself, in order to play back the audio of a specified message, it is necessary to record the message on the magnetic tape. The location of the recording must be found by rolling the magnetic tape. Therefore, there is a drawback that there is a large time difference between when a regeneration request is issued and when regeneration becomes possible. Furthermore, since the amount of magnetic tape used increases in proportion to the elapsed time, regardless of whether the message is voiced or silent, the efficiency of using the magnetic tape may deteriorate depending on the way the message is spoken.

Similarly, message voice recording devices, ie voice mailboxes, in digital voice packet switching networks also have the disadvantage that the memory for storing digital information is used less efficiently.

The purpose of the present invention is to improve the usage efficiency of voice information storage memory for messages by compressing the amount of silent information in digital voice information in voice mailbox services in digital voice packet switching networks, and to improve access during voice playback. To provide a message voice recording device capable of shortening time.

In order to achieve the above object, the message voice recording device in a digital voice packet switching network according to the present invention temporarily stores voice information from a calling terminal and transmits the voice information to a corresponding receiving terminal. In a message voice recording device in a network, a voice information frame format is composed of frame synchronization, voice frequency information, voice amplitude information, and a presence/absence display bit, and when the presence/non-display bit indicates a voice presence, it is used as is. When the presence/absence display bit indicates silence, a counter is counted up and nothing is output, and when there is no sound, frame synchronization is performed, and it forms part of the format together with the presence/absence display bit. A compression unit sets the count value in a silence duration counter value field, and when the compression unit outputs a frame with a sound display, it outputs it in the same format, and when a frame with a silence display is output, it outputs it in the same format. A digital audio information compression device is provided having a digital audio information expansion unit that outputs frames of the same format as many times as set in the silence duration counter value field, and the audio information from the calling terminal is stored via the compression unit. However, the temporarily stored voice information is configured to be sent to the receiving terminal via the expansion section.

According to the above configuration, the object of the present invention can be completely achieved.

Hereinafter, the present invention will be explained in more detail with reference to the drawings.

FIG. 1 is a block diagram showing one embodiment of the present invention. In this embodiment, the message voice recording device corresponds to the exchange 9, and the exchange 9 corresponds to the central processing unit 4,
It consists of a magnetic disk device 5, a digital audio information compression device 8 including a digital audio information compression section 6, and a digital audio information expansion section 7. In the figure, 1 is the originating terminal, 3 is the receiving terminal, and 2 is located between the originating terminal 1 and the exchange 9, which converts analog information from the originating terminal into digital voice information, and from the receiving terminal 3 to the originating terminal 1 through the exchange. This is an audio information analog-to-digital converter that converts transferred digital audio information into analog audio information.

FIG. 2a shows an example of the audio information frame format input to the digital audio information compression section 6.
Figure b shows a sound frame (format 1), and figure c shows a silent frame (format 2). FIG. 3 shows the audio information frame format after compression, where a shows a voice frame (format 3) and b shows a silent frame (format 4). In each figure, S, F, A, V, and C indicate a frame synchronization bit, audio frequency information, audio amplitude information, a sound/silence display bit, and a silence duration counter, respectively.

When format 1 is input, the compression unit 6 of the digital audio information compression device 8 provided in the switching center 9 displays the sound/silence display bit (V) as a sound signal, so no changes can be made. The frame is output in Format 3 (=Format 1) format. Furthermore, when format 2 is input, since the display is silent, a silent frame counter (CNT) (not shown) is counted up and nothing is output. When format 1 is input, if the silent frame counter (CNT) is other than 0, format 4 is first output, and then format 1 is output without any processing. At this time, the silent frame counter (CNT) value is set in the C field of the silent frame of format 4, and the CNT
itself is reset to 0. If the silent frame counter (CNT) is 0, only format 1 is output as is. Also, when format 3 is input, the expansion section 7 is displayed with audible sound, so the frame is not changed at all and the frame is output in the format 1 (=format 3), and when format 4 is input Since the display is silent, frames of format 2 are output as many as the number of counters set in the C field.

FIG. 4 is a diagram for explaining the embodiment of FIG. 1 configured as described above. The voice mailbox service between the calling terminal 1 and the receiving terminal 3 will be explained below using FIG. When the exchange 9 receives a calling signal from the calling terminal 1, the exchange 9 sends a dialable signal to the terminal 1. Terminal 1
sends the dial to the conversion station 9, but the switching station 9 identifies the destination from the dial information and checks whether the destination terminal is usable or not. When the destination terminal (in this case, the destination is the receiving terminal 3) is busy, the exchange 9 sends a busy signal to the calling terminal 1. If the originating terminal 1 wishes to request a voice mailbox service, it sends a mailbox request signal to the exchange. If there is an empty area on the magnetic disk device 5 and the mailbox service can be accepted, the exchange 9 sends a mailbox enable signal to the originating terminal 1. Upon receiving the mailbox enable signal, the originating terminal 1 speaks (sends) a message to the exchange 9. The analog voice information sent from the terminal is converted into digital voice information by the voice information analog-to-digital converter 2 and temporarily stored on the memory in the central processing unit 4. Thereafter, the digital audio information is sent to the digital audio information compression section 6 of the digital audio information compression device 8, where the silent audio information is processed into the format described above.
That is, the information is compressed, and the amount of information is compressed and output to the central processing unit 4. This compressed audio information is stored in the magnetic disk device 5 together with management information.

On the other hand, when the receiving terminal 3 predicts that a message addressed to it is stored in the exchange 9, it makes a call, and after receiving a dialable signal from the exchange, dials an instruction to inquire about the mailbox. Upon receiving this dial, the exchange 9 searches the magnetic disk 5 for a message addressed to the terminal and reads it into the memory in the central processing unit 4. Furthermore, this information is sent to the digital audio information expansion section 7 of the digital audio information compression device 8. This voice information is expanded and restored by the digital voice information expansion section into the same digital voice information as received by the exchange 9 from the originating terminal 1. This information is sent to the receiving terminal 3 through the audio information analog-to-digital converter 2. Note that the digital voice information is converted into analog voice information by the voice information analog-to-digital converter 2 and transmitted to the receiving terminal.

As explained above, the apparatus according to the present invention is configured to reduce the amount of voice information by using a digital voice information compression device in a voice mailbox system in a digital voice packet switching network. Therefore, it is possible to reduce the amount of memory required for the magnetic disk device used in the voice mailbox, and at the same time to shorten the access time during voice reproduction.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing one embodiment of the message voice recording device according to the present invention, FIG. 2 is a diagram showing an example of the audio information frame format input to the digital audio information compression section, and FIG. FIG. 4 is a diagram showing an audio information frame format after compressing the frame format shown in the figure, and is a diagram for explaining an example of the operation of this embodiment. 1... Calling terminal (A), 2... Voice information analog-digital converter (VOC), 3... Receiving terminal (B), 4... Central processing unit (CPU), 5... Magnetic disk device (DISK), 6... Digital Audio information compression section, 7...
Digital voice information expansion unit, 8...Digital voice information compression device, 9...Switching station.

Claims (1)

[Claims] 1. Temporarily store voice information from a calling terminal and send the voice information to the corresponding receiving terminal. In a message voice recording device in a digital voice packet switching network, the voice information frame format is composed of frame synchronization, voice frequency information, voice amplitude information, and presence/absence indication bits, and
When the non-display bit indicates sound, it outputs in the same format, and when the presence/non-display bit indicates silent display, a counter is counted up,
A compression unit that outputs nothing and performs frame synchronization in the case of silence, and sets the count value in a silence duration counter value field that forms part of the format together with the presence/absence indication bit; When a frame is output, the frame is output in the same format, and when a frame displaying silence is output, the number of frames set in the silence duration counter value field is output as many frames in that format. a digital audio information compression device having a section, configured to store audio information from the calling terminal via the compression section, and send the temporarily stored audio information to the receiving terminal via the expansion section. 1. A message voice recording device for a digital voice packet switching network, characterized in that: