KR20050058005A - Apparatus and method for automatic detection of vad in key phone system - Google Patents

Abstract

The present invention is to provide a VAD automatic sensing device and method of the key phone system, DBID interfaced with the highway structure; A VCEU / DSP capable of detecting a voice compression, VAD, CPT, and increasing a voice channel by allocating a required voice channel from the DBID; A CPU which transmits and receives HDB data and MPB of a key phone system and exchanges signals with the VCEU / DSP; An MLU under the control of the CPU and for supporting multiple languages in a system; FMEU for storing the compressed voice signal under the control of the CPU; By including the VAD level storing the VAD level of the key line system trunk line under the control of the CPU, the voice storage unit board is installed in the key phone system to automatically detect the state of the external trunk line and the VAD of each line By managing reference levels, the system can improve reliability.

Description

Apparatus and method for automatic detection of VAD in key phone system}

The present invention relates to an apparatus for automatically detecting Voice Activity Detection (VAD) of a keyphone system and a method thereof, and in particular, a voice mail interface board (VMIB) is installed in a keyphone system to automatically detect a state of an external trunk line. And a method for automatically detecting a VAD of a key phone system and managing the VAD reference level of each line to improve the reliability of the system.

In general, a key phone system is an efficient simple exchange system designed to be used by several people at the same time by installing a limited trunk line in the key phone main unit and connecting a key phone and a regular phone. The key phone system may be connected to a trunk line and an extension to perform a voice guidance function, interrupting function, broadcasting function, reception rejection function, remote maintenance function, and the like.

1 is a schematic cross-sectional view of a typical keyphone system.

Therefore, the KSU (Key Service Unit) is composed of three, the first KSU 13, which is a basic (Basic) KSU, the second KSU (12), the third KSU 11 is an extended KSU.

The basic KSU 1'st KSU 13 is a power supply unit (PSU) 14 for supplying power, various peripherals (PP) 15, and a main process board (MPB) 16 for controlling and monitoring the entire system. ) And a link module unit (LMU) 17 for interfacing with the second KSU 12.

2 is a block diagram of an MPB in a conventional key phone system. This shows the internal block of the MPB 16 in the first KSU 13 of FIG.

Thus, an edge connector 39 connected to the first KSU 13 MPB slot of FIG. 1, a reset 24 for resetting the system and a CPU, and a LAN Local Area Network Interface (I / F) ( 25), a regulator 26 for supplying necessary power inside the MPB 16, a CPU 40 for controlling the operation of the system programmatically, a programmable memory unit (PMU) 27, and static random (SRAM). Access Memory (28), Internal Input / Output (I / O) (29) for common input and output ports, Peripheral Input / Output (PP I / O) (210), and Dual (Dual) for modem control and serial communication. Asynchronous Receiver / Transmitter) 31, MODU 33, and RS234C port 34.

In addition, GSXD (GoldStar eXchange Device) (22) switching Pulse Code Modulation (PCM) voice data, Tone ROM (23) providing various tones, and PLL (Time Division Multiple Access) PLL (CDMA) provide clocks for time division multiple access (TDMA) PCM voice data. Phase Locked Loop (21), Digital Backplane Interface Device (DBID) 32, which provides PCM voice signals in MPB 16, input I / O 35, output I / O 36, input voice channel ( 37) and an output audio channel 38.

3 is a structural diagram showing a highway structure used in FIG.

The operation of the conventional apparatus will be described in detail with reference to the accompanying drawings as follows.

First, the key phone system is composed of three KSU (Key Service Unit) (11) 12 (13).

The CPU 40 of the MPB 16 controls and operates the entire system.

Thus, when the PSU 14 of the first KSU 13 is turned on while the second KSU 12 and the third KSU 11 are powered on, the CPU 40 may generate some kind of PP B //. It recognizes whether the D 15 is installed and allocates a Pulse Coded Modulation (PCM) voice time slot to each of the PP B / Ds 15.

The voice time slot is determined by the capacity of the system and can be represented by the highway structure of FIG. 3 and is created in the GSXD 22. This timing is made based on the clock supplied from the PLL 21.

The highway structure of FIG. 3 describes one highway. The highway consists of eight sub-frames, and one sub-frame consists of one 512 Kbps High-level Data Link Control (HDLC) channel, D channel, and six voice channels.

Accordingly, there are 48 64 Kbps voice channels in one frame.

64Kbps voice data is loaded on the highway with 8K sampling (8K x 8bit = 64kbits). These highways are divided into TX highways and Rx highways, and nine support highways and eight support highways.

One more transmit highway than the receive highway is used as the tone highway, which provides a variety of tones to the PP (Peripheral) board 15 mounted in the slot.

The total number of voice channels supported by the GSXD 22 is 8 (highway number) x 48 (number of voice channels of one highway) = 384 voice channels.

In the system configuration as shown in FIG. 1, the first KSU 13 and the second KSU 12 are assigned three highways, and the third KSU 11 is assigned two, so that (48 x 3 + 48 x 3 + 48 x 2 = 144 + 144+ 96 = 384) It can support up to 384 ports.

The HDLC channel of the highway of FIG. 3 is used for data communication between the CPU 40 of the MPB 16 and the CPU of the PP 15.

However, this conventional technology has the following problems.

In other words, the conventional PP is a board that supports trunk lines, stations, and the like, and only processes PCM voice data provided by MPB. Therefore, there is no function to detect the state of CO line by data communication between MPB and PP board. Accordingly, since the reference point of the VAD level is defined as a specific level (about 36 dBm), the VAD and ring back tone, error tone, and busy tone are used in a CO line in which the state of the CO line is poor. There was a problem that an error occurs when detecting.

Therefore, the present invention has been proposed to solve the conventional problems as described above, an object of the present invention is to install the voice storage board in the key phone system automatically detects the state of the external trunk line and the VAD reference level of each line It is to provide a VAD automatic detection device and method of the key phone system that can improve the reliability by managing the system.

In order to achieve the above object, the VAD automatic detection device of the key phone system according to an embodiment of the present invention,

A DBID interfaced with the highway structure; A VCEU / DSP capable of detecting a voice compression, VAD, CPT, and increasing a voice channel by allocating a required voice channel from the DBID; A CPU which transmits and receives HDB data and MPB of a key phone system and exchanges signals with the VCEU / DSP; An MLU under the control of the CPU and for supporting multiple languages in a system; FMEU for storing the compressed voice signal under the control of the CPU; The technical configuration is characterized by including the VAD level under the control of the CPU and storing the VAD level of the key line system trunk line respectively.

In order to achieve the above object, a VAD automatic detection method of a key phone system according to an embodiment of the present invention,

A first step of detecting a ringback tone by converting the ring back tone into a VAD reference level of the trunk line by occupying a designated trunk line in VMIB, which is a VAD automatic sensing device of a key phone system; The technical configuration is characterized by including the second step to perform the necessary service when the ring signal comes from the designated CO line after the first step.

Hereinafter, an embodiment according to the present invention, a VAD automatic sensing device of a key phone system, and a method thereof will be described with reference to the accompanying drawings.

4 is a block diagram of a VAD automatic sensing device of a key phone system according to the present invention, FIG. 5 is a timing diagram between a CPU and a DBID in FIG. 4, and FIG. 6 is a timing diagram of recording and storage times used in FIG. 4. .

As shown therein, the DBID 52 interfaces with the highway structure; VCEU / DSP (Voice Channel Expansion Unit / Digital Signal Processing) which can allocate voice channel from DBID 52 to detect voice compression, voice activity detection (VAD), call progress tone (CPT), and increase voice channel 50; A CPU 45 for transmitting and receiving HDLC data with the MPB 16 of the key phone system and exchanging signals with the VCEU / DSP 50; A multi-language unit (MLU) 46 which is controlled by the CPU 45 and supports a multi-language to a system; A flash memory expansion unit (FMEU) 49 which stores the compressed voice signal under the control of the CPU 49; And a VAD level 56 under the control of the CPU 45 and storing the VAD levels of the key line system trunk line, respectively.

In the above, the VAD automatic sensing apparatus of the key phone system includes: a clock (41) for supplying a clock to the CPU (45) and the VCEU / DSP (50); A reset (42) for the reset and watchdog (WDG) of the CPU (45); RS232 (43) connected to the CPU (45) so that the status of the board can be checked from the outside; A LAN 44 connected to the CPU 45 to support a LAN; A NOR flash 47 controlled by the CPU 45 and storing software code for operating a board; A RAM 48 controlled by the CPU 45 and storing necessary data; A JTAG (51) for debugging the VCEU / DSP (50); An I / O 53 connected to the DBID 52 to perform general purpose input / output; A DC converter (54) for supplying power for the VAD automatic sensing device of the key phone system; It is further configured to include an edge connector (55) connected to the DBID (52) to be connected to the backplane board of the keyphone system.

7 is a flowchart illustrating a VAD automatic detection method of a key phone system according to the present invention.

As shown in FIG. 1, a first step of detecting a ring back tone by converting a ring back tone to a VAD reference level of a trunk line by occupying a designated trunk line in VMIB, a VAD automatic detection device of a keyphone system, ST11 to ST16); After the first step, if a ring signal comes from a designated CO line, a second step (ST17 to ST29) to perform a necessary service is performed.

The first steps ST11 to ST16 may include: specifying a trunk line in the VMIB and then occupying a designated trunk line (ST11) (ST12); Detecting a ring back tone level after occupying the designated trunk line for a predetermined time and converting the detected ring back tone level into a VAD reference level of the trunk line (ST13); Storing the reference VAD level in a VAD level after the conversion (ST15); And performing the second step when the ring signal comes from the designated trunk line after the storing (ST16).

In the second step (ST17 ~ ST29), if the necessary service is in the playback mode, after reading the ADPCM (Adaptive Differential Pulse Code Modulation) data from the FMEU (49) and transfers to the VCEU / DSP (50) (ST17) (ST18); And converting ADPCM data into PCM data in the VCEU / DSP 50 (ST19).

The second step ST17 to ST29 may include: a storage step of converting the input PCM data into the ADPCM data and then storing the ADPCM data in the FMEU 49 when the required service is the recording mode (ST21 to ST24); After the storing step is performed including the recording end step (ST25 ~ ST29) to end the recording until a certain condition is achieved.

In the recording end steps ST25 to ST29, a predetermined condition is set to compare the value of the occupied trunk line level with the value of the reference VAD level, and determines whether to end the recording according to the comparison result (ST25).

In the recording end step (ST25 ~ ST29), a certain condition is set to the call progress tone (CPT) busy duration, ring back tone, error tone for more than a predetermined time, whether or not to terminate the recording according to whether or not the CPT Determine (ST26).

In the recording end steps ST25 to ST29, a predetermined condition is set to compare the level of the occupied trunk line with a preset value, and determines whether to end the recording according to the comparison result (ST27).

Referring to the accompanying drawings, the operation of the VAD automatic sensing device and method of the key phone system according to the present invention configured as described above will be described in detail as follows.

First, the present invention is to install a voice mail interface board (VMIB) in the key system to automatically detect the state of the external trunk line and to manage the VAD reference level of each line.

Therefore, in the present invention, the voice mail interface board (VMIB) board according to the present invention is installed in the PP B / D 15, which is a universal slot of the key phone system of FIG.

When the board installed in the PP B / D 15 becomes the external analog trunk line interface to access the system, the CPU 40 of the MPB 16 forms a loop of the analog trunk line, and the analog interface trunk line board receives the analog audio signal. By converting the PCM data into the highway structure of FIG. 3, the PCM data is introduced into a GSXD (GoldStar eXchange Device) 22 performing a switching function in the MPB 16 to share and use a voice signal in the system.

PCM data output from the GSXD 22 is input to the edge connector 55 of the VMIB of FIG. 4.

The digital back plane interface device (DBID) 52 processes 32 voice channels in one frame (8KHz = 125us) as shown in the timing diagram shown in FIG. 5, where 8 voice channels are connected (Ch1, Ch2). , Ch3, Ch4, Ch16, Ch17, Ch18, Ch19).

One VCEU / DSP 50 handles four channels, and if one optional VCEU / DSP is installed, two VCEU / DSP 50 handles eight channels, so two VCEU / 50 One VMIB with) handles eight channels.

One VCEU / DSP 50 compresses four channels of PCM data into 32Kbps ADPCM for every 125us and stores them in the internal memory of the DSP for 30ms (4Kbytes).

The stored 32 Kbps ADPCM data for each of the four channels is read by the CPU 45 in the first time slot of 30 ms (3 ms), as shown in FIG. 6, and the CPU 45 is within the time allotted for each channel. The SRAM 48 and the NAND Flash ROM FMEU 49 are stored.

The first in the recording and storage time timing diagram of FIG. 6 is a time slot used to read or write 32 Kbps ADPCM data stored in the VCEU / DSP 50.

When the optional VCEU 50 is installed, two VCEU / DSPs 50 perform services and simultaneously process 8 channels within 3ms.

The second time slot is used to store or read voice data of the first 32 Kbps ADPCM channel of the eight channels, and the ninth slot is used to store or read voice data of the eighth 32 Kbps ADPCM channel. The last tenth time slot is reserved and used for other purposes.

As described above, the DSP 50 receives the PCM data allocated from the DBID 52, compresses the data into 32 Kbps ADPCM data, and delivers the voice to the CPU 45 every 30 ms.

In this manner, when the FMEU 49 recorded 32 Kbps ADPCM data made of NAND Flash is reproduced, the CPU 45 writes the DSP 50 to the timing of FIG. 6.

In order to increase the recording time of the FMEU (49) NAND Flash, the FMEU is extended.

As described above, the time for reading and writing data at a predetermined time between the DSP and the CPU is very important for recording the voice.

To improve the quality of the voice, DSP uses an algorithm to compress the voice to 32Kbps ADPCM.

To do this, the DSP 50 must operate at least 100 MIPS or more, and the CPU 45 must operate at 50 MHz or more.

When calling the system by an external analog trunk line, when the CPU 40 of the MPB 16 designates a specific trunk line as the VMIB of FIG. 4, the CPU 45 of the VMIB operates the DSP 50 and the NAND. The system sends a system greeting message stored in the flash 49 and enters the recording mode.

In order to record and know when the recording is completed, the DSP 50 should detect Voice Activity Detection (VAD) and Call Progress Tone, Error Tone, and Busy Tone (CPT) of the designated CO line.

The DSP 50 detects the reference level of the VAD by about 40 dBm, and detects error tones and busy tones that are call progress tones.

So 40dBm is not a problem in the VAD detection reference level when it is a normal CO line. However, since all CO lines connected to the system cannot be regarded as normal, the CPU 40 of the MPB 16 is idle when the CO line is not occupied. In the) state, the CO line is forcibly held and an HDLC command is given to the CPU 45 of the VMIB based on the timing diagram as shown in FIG. 3.

Then, the CPU 45 reads PCM data of the CO line designated by the DSP 50 from the DBID 52, calculates the VAD reference level for every 30 ms for 7 seconds, determines the reference level, and stores it in the VAD level 56. The result is reported to the CPU 40 of the MPB 16.

The CPU 40 of the MPB 16 disconnects the designated trunk line and stores the VAD reference level for each trunk line to detect each trunk line state and allow the normal VAD to detect the VMIB.

If the reference level of a particular trunk line is, for example, 10 dBm or more, the system determines that the line state for that particular trunk line is bad, and the system can perform an alarm process.

In addition, it is possible to show the VAD reference level of the designated trunk line through the RS232 43 to an external PC.

The DSP 50 of the present invention processes PCM and 32 kbps ADPCM signal conversion compression, VAD, and CPT.

In addition, the DSP 50 downloads a signal input to an external LAN 44, for example, a music file having an extension of a wave format, and stores it in the NAND Flash 49 in 32 Kbps ADPCM data format to be connected to the system. Various melodies can be delivered to the terminal. Of course, the stored ADPCM data is converted to PCM data in the DSP (50).

Meanwhile, the overall operation of the present invention will be described with reference to FIG. 7.

The VMIB occupies the designated CO line and converts the state of the CO line to the VAD reference level of the CO line after detecting the tone.

The reference VAD level is then stored in the VAD level 56.

When the ring signal comes from the designated trunk line, the VMIB determines from the MPB 16 the recording or playback mode on the designated trunk line.

In the playback mode, data stored in the NAND Flash 49 is sent to the DSP 50, and the DSP 50 sends a 64 kbps PCM audio signal to the designated trunk line to process the playback mode.

In the recording mode, the occupied trunk line level is 7 seconds or more than the value of the reference VAD level, or CPT (call progress tone; busy tone, ring back tone, error tone) lasts 7 seconds or longer, or is occupied. If it lasts more than 7 seconds for more than 10dBm, recording will end.

As such, the present invention automatically detects the state of the external trunk line in the key phone system and manages the VAD reference level of each line.

Although the preferred embodiment of the present invention has been described above, the present invention may use various changes, modifications, and equivalents. It is clear that the present invention can be applied in the same manner by appropriately modifying the above embodiments. Accordingly, the above description does not limit the scope of the invention as defined by the limitations of the following claims.

As described above, the apparatus and method for automatically detecting a VAD of a keyphone system according to the present invention automatically install the VMIB, which is a voice storage board, in the keyphone system to automatically detect the state of an external analog trunk line and automatically determine the VAD reference level of each line. By managing the system will have the effect of improving the reliability.

In addition, when the VAD reference level is above a certain level in the idle state of the CO line, the state of the particular CO line can be treated as an alarm.

1 is a schematic cross-sectional view of a typical keyphone system,

2 is a block diagram of a MPB in a conventional key phone system,

3 is a structural diagram showing a highway structure used in FIG.

Figure 4 is a block diagram of a VAD automatic detection device of a key phone system according to the present invention,

FIG. 5 is a timing diagram between a CPU and a DBID in FIG. 4;

FIG. 6 is a timing diagram of recording and storage time used in FIG. 4.

7 is a flowchart illustrating a VAD automatic detection method of a key phone system according to the present invention.

Explanation of symbols on the main parts of the drawings

41: clock 42: reset

43: RS232 44: LAN

45: CPU 46: MLU

47: NOR Flash 48: RAM

49: FMEU 50: VCEU / DSP

51: JTAG 52: DBID

53: I / O 54: DC converter

55: edge connector 56: VAD level

Claims (9)

A DBID interfaced with the highway structure; A VCEU / DSP capable of detecting a voice compression, VAD, CPT, and increasing a voice channel by allocating a required voice channel from the DBID; A CPU which transmits and receives HDB data and MPB of a key phone system and exchanges signals with the VCEU / DSP; An MLU under the control of the CPU and for supporting multiple languages in a system; FMEU for storing the compressed voice signal under the control of the CPU; And a VAD level under the control of the CPU and storing a VAD level of a key line system trunk line, respectively. According to claim 1, VAD automatic detection device of the key phone system, A clock for supplying a clock to the CPU and VCEU / DSP; A reset for a reset and a watchdog of the CPU; RS232 connected to the CPU to check the status of the board from the outside; A LAN connected to the CPU to support a LAN; A NOR Flash under control of the CPU and storing software code for operating a board; A RAM under control of the CPU and storing necessary data; JTAG for debugging the VCEU / DSP; An I / O connected to the DBID to perform general purpose input / output; A DC converter for supplying power for the VAD automatic sensing device of the key phone system; And an edge connector which is connected to the DBID to be connected to the backplane board of the keyphone system. A first step of detecting a ringback tone by converting the ring back tone into a VAD reference level of the trunk line by occupying a designated trunk line in VMIB, which is a VAD automatic sensing device of a key phone system; And a second step of performing a necessary service when a ring signal comes from a designated trunk line after the first step. The method of claim 3, wherein the first step, Designating a trunk line in the VMIB and then occupying a designated trunk line; Detecting a ring back tone level for a predetermined time after occupying the designated CO line, and converting the detected ring back tone level into a VAD reference level of the CO line; Storing the reference VAD level in a VAD level after the conversion; And performing the second step when the ring signal comes from the designated trunk line after the storing. The method according to any one of claims 3 to 4, wherein in the second step, if the required service is a playback mode, Reading ADPCM data from FMEU and forwarding it to VCEU / DSP; And converting ADPCM data into PCM data in the VCEU / DSP. The method according to any one of claims 3 to 4, wherein if the required service is the recording mode in the second step, A storage step of converting the input PCM data into ADPCM data and then storing the ADPCM data in FMEU; And a recording end step of terminating recording until the predetermined condition is achieved after the storing step. The method of claim 6, wherein the predetermined condition in the recording end step, And comparing the value of the level of the occupied trunk line with the value of the reference VAD level, and determining whether to end recording according to the comparison result. The method of claim 6, wherein the predetermined condition in the recording end step, A method of automatically detecting VAD of a keyphone system, characterized in that the call progress tone (CPT) is set to continue for a predetermined time or more, and the recording end is determined according to whether the CPT is continued. The method of claim 6, wherein the predetermined condition in the recording end step, A method for automatically detecting VAD of a keyphone system, characterized by determining whether to end recording based on a comparison result by setting the level of occupied trunk lines to a preset value.