JP3756724B2 - Telephone equipment - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a telephone apparatus such as a single telephone, a button telephone apparatus, and a private branch exchange connected to a packet network.
[0002]
[Prior art]
A conventional telephone device is designed to be connected to a circuit switched network, and an echo canceller is designed. By correlating the voice signal of the local station and the reflected signal that is reflected back on the other party side, The sound attenuation level and side sound delay time were measured and used to cancel echo.
[0003]
[Problems to be solved by the invention]
However, in recent years, a packet network is used in addition to a circuit switching network, and it is not guaranteed that each packet passes the same route. Therefore, in a telephone device using the echo cancellation method as described above, There was a problem that side sounds could not be reduced appropriately.
[0004]
The present invention has been made as a solution to the problems of the telephone apparatus as described above, and an object of the present invention is to provide a telephone apparatus that can appropriately perform echo cancellation even in a packet network.
[0005]
[Means for solving the problems]
A telephone device according to the present invention is connected to a packet network, and when a packet is sent , the packet is disassembled to extract a signal, and when a voice signal is sent, a packet disassembling / assembling unit and a transmitter A delay unit for delaying the audio signal input from the packet, an audio signal obtained by decomposing by the packet decomposing / assembling unit, and an audio signal delayed by the delay unit, and receiving the delay based on the comparison result A cancellation amount control unit that outputs an echo cancellation signal that attenuates the audio signal delayed by the unit, and an echo cancellation signal output from the cancellation amount control unit and the packet decomposition / assembly unit. Each time an audio packet containing the transmission time information together with the audio data sent from the other party's telephone device is received, Means for extracting time information from the transmission time, detecting a time required for the arrival of the voice packet as compared with the current time, and setting the delay unit with a time twice as long as this time characterized in that it.
[0006]
The telephone device according to the present invention further includes packetizing means for adding a time information at that time to packetize the voice signal input from the receiver by the packet disassembly / assembly unit. Features.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
A telephone device according to the present invention will be described below with reference to the accompanying drawings. Here, a button telephone apparatus will be described as a telephone apparatus, but it goes without saying that the present invention can be applied to a single telephone or a private branch exchange.
[0009]
As is clear from the configuration diagram shown in FIG. 1, a key telephone 2 is connected to the main apparatus 1 in the key telephone according to the embodiment. As shown in FIG. 2, the main device 1 is connected to the packet network 3 and can communicate with the counterpart main device 1A. A key telephone 2A is connected to the main apparatus 1A.
[0010]
As shown in FIG. 1, the main apparatus 1 controls a transmission unit 11 that transmits / receives packets to / from the packet network 3, a packet disassembly / assembly unit 12 that performs packet disassembly and assembly, and the like. A control unit 10 is provided.
[0011]
On the other hand, the key telephone 2 includes a transmitter 21 and a receiver 22, a call circuit 23, an A / D converter 24, a D / A converter 25, an echo canceller 26, and an operation unit 27.
[0012]
The echo canceller 24 includes a delay unit 31 that delays the voice signal input from the transmitter 21, a cancellation amount control unit 32 that controls the amount of echo cancellation, and the output of the cancellation amount control unit 32 and the incoming voice signal. Is added.
[0013]
In the above, the delay unit 31 controls the delay amount based on an instruction from the control unit 10. The cancellation amount control unit 32 compares the audio signal output from the delay unit 31 and the audio signal output from the packet disassembly / assembly unit 12 to determine the cancellation amount.
[0014]
The operation unit 27 includes keys such as a hook switch and dial keys, an LED for displaying an operation state, and a speaker.
[0015]
The control unit 10 includes a clock (not shown), and time data obtained from this clock is sent to the packet disassembly / assembly unit 12. The packet disassembly / assembly unit 12 adds the time data at that time to the voice packet to be transmitted, and transmits the data as, for example, data having a format as shown in FIG.
[0016]
The format of the voice packet in FIG. 3 will be described. A packet header in which information such as a destination, a transmission source, and a packet type is set is provided at the head of the packet. Next to the packet header, audio data and further time data are set.
[0017]
The operation when the main apparatus 1 and the key telephone 2 configured as described above are connected to the main apparatus 1A and the key telephone 2A similarly configured via the packet network 3 as shown in FIG. This will be described based on the flowcharts shown in FIGS.
[0018]
The control unit 10 of the main apparatus 1 (1A) detects whether an off-hook signal is sent from the operation unit 27 or an incoming call control packet is sent from the other party via the packet network 3 (S1). , S2). Here, when an off-hook is detected, the packet disassembly / assembly unit 12 is instructed to transmit a call control packet for calling (S3), and a calling process is executed (S3). When received, the control unit 10 that has received the packet from the packet disassembly / assembly unit 12 controls the speaker of the operation unit 27 to generate a ringing tone and blink the LED (S4). .
[0019]
After the outgoing call process (S3) or the incoming call process (S4), the response of both calls is detected (S5), and the voice packet sent from the packet network 3 side is taken in (S6). Time data is taken out, and the delay amount and cancellation amount are controlled based on the time data (S7).
[0020]
The detailed operation in step S7 is as follows. When the control unit 10 extracts the time data, the control unit 10 compares the time data with the time of the clock provided therein, and detects that the voice packet has arrived after the time t, for example. The side sound is not strict because the voice signal transmitted from the main device 1 reaches the main device 1A via the packet network 3 and is input from the key telephone 2A through the reflection path. It is estimated that 2t will come back from the time of transmission.
[0021]
Therefore, the control unit 10 instructs the delay unit 31 of the echo canceller 26 to delay 2t. As a result, the voice signal input from the transmitter 21 is delayed by 2t by the delay unit 31 and reaches the cancellation amount control unit 32. The cancellation amount control unit 32 takes in the audio signal transmitted from the packet disassembly / assembly unit 12 and compares it with the audio signal (2t delayed signal) output from the delay unit 31.
[0022]
In the above comparison, the signal output from the delay unit 31 is a voice signal sent from the button telephone apparatus side 2t before the time, and has, for example, the waveform of the signal component s1 as shown in FIG. Suppose there is. On the other hand, in the voice signal sent from the packet disassembly / assembly unit 12, the side signal component s11 of the signal component s1 is superimposed on the voice signal component s2 input by the partner at the partner telephone / phone device. A waveform having the components shown in FIG. Therefore, as a result of comparison, in the signal component s1 and the side-tone signal component s11, the level of the signal component s11 is lower than that of the signal component s1, and the amount of attenuation corresponding to the difference is given to the signal component s1 to perform the cancellation amount control. Done.
[0023]
Addition (actually subtraction) of the signal component s12 and signal component s11 obtained by attenuating the signal component s1 is performed in the adder 33 to reduce the side sound.
[0024]
When the above control is performed, voice packet arrival and on-hook detection are performed as shown in FIG. 5 (S8, S9), and steps S6 and S7 are repeated when a packet arrives. Proceed to the talk process (S11). In the call termination process, the packet disassembly / assembly unit 12 transmits a call control packet for disconnection. If a disconnection packet is given from the packet disassembly / assembly unit 12 when on-hook is not detected (S10), a call termination process for transmitting a call control packet for disconnection from the packet disassembly / assembly unit 12 in response thereto (S11). I do.
[0025]
As described above, according to the present embodiment, the synthesis timing of the echo cancellation signal (signal component s12) using the transmission signal and the reception signal (s2 + s11) using the transmission time data included in the voice packet is as follows. Control and proper echo cancellation is performed.
[0026]
【The invention's effect】
As described above, according to the telephone device of the present invention, the timing of synthesizing the echo cancellation signal using the transmission signal and the reception signal is controlled based on the time information included in the voice packet transmitted from the other party. In addition, there is an effect that echo cancellation is appropriately performed even when a network using voice packets that may take different paths is used.
[0027]
As described above, according to the telephone device according to the present invention, when the voice signal input from the handset is packetized and transmitted, the time information is added and packetized. The echo cancellation using the transmission signal can be performed based on the time information.
[Brief description of the drawings]
FIG. 1 is a configuration diagram of a telephone device according to the present invention.
FIG. 2 is a configuration diagram of a system using a telephone device according to the present invention.
FIG. 3 is a view showing a format of a voice packet used in the telephone device according to the present invention.
FIG. 4 is a flowchart showing the operation of the telephone device according to the present invention.
FIG. 5 is a flowchart showing the operation of the telephone device according to the present invention.
FIG. 6 is a waveform diagram showing the operation of the telephone device according to the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1, 1A Main apparatus 2, 2A Key telephone 3 Packet network 10 Control part 11 Transmission part 12 Packet disassembly / assembly part 21 Transmitter 22 Receiver 23 Communication circuit 24 A / D converter 25 D / A converter 26 Echo canceller 27 Operation unit 31 Delay unit 32 Cancellation amount control unit 33 Adder

Claims (2)

A packet disassembling / assembling unit that is connected to a packet network, disassembles the packet when the packet is sent out, extracts a signal, and packetizes the voice signal;
A delay unit that delays a voice signal input from the transmitter;
The audio signal obtained by the packet decomposition / assembly unit and the audio signal delayed by the delay unit are received, and the audio signal delayed by the delay unit is attenuated based on the comparison result. A cancellation amount control unit for outputting an echo cancellation signal;
An adder for adding the echo cancellation signal output from the cancellation amount control unit and the audio signal obtained by decomposition by the packet decomposition / assembly unit;
Every time a voice packet containing transmission time information is received together with voice data sent from the other party's telephone device, the transmission time information is extracted from the voice packet, and it is necessary until the voice packet arrives compared with the current time. Means for detecting the set time, and setting the delay unit with a time twice as long as this time
A telephone apparatus comprising: The packetizing means for adding the time information at that time to packetize the voice signal input from the handset when the packet disassembling / assembling unit packetizes the voice signal. Telephone equipment.

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