JPH05284560A - Call monitoring system - Google Patents

Abstract

(57) [Abstract] [Purpose] An object of the present invention is to provide a call monitor system for use in a mobile phone call of a digital mobile communication system, and to enable a call monitor for a low-speed encoded voice signal. A digital mobile communication system having switching stations (5, 6) for connecting mobile stations to each other while keeping the low-speed encoded signal as they are, and when monitoring a call between mobile stations, Input signal distribution means 21 and 22, signal conversion means 31 and 32 for converting a low-speed encoded signal into a PCM signal, and call monitor means 4 are provided, and the low-speed encoded signal transmitted from the mobile device is provided. The signal is distributed by the corresponding input signal distribution means, and one part is not converted and is connected to the other party's mobile station via the other party's exchange station, but the remaining part is converted to a PCM signal by the corresponding signal conversion means and is converted to the call monitor means. The connection is established, and the communication between the mobile units can be monitored by using the communication monitoring means.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a call monitor system used in a mobile phone call in a digital mobile communication system.

In a digital mobile communication system,
64Kb used in fixed network from the viewpoint of effective use of radio waves
11.2Kb / s and VSELP (Ve
(ctorSum Excited Linear Prediction) method was adopted.However, when this method is used, the method of connecting between mobile units is not converted to the signal of PCM method as described later, and the method of connecting as it is is suitable for the call. , It became impossible to monitor the call as it was.

Therefore, it is necessary to enable a call monitor for low-speed encoded voice signals.

[0004]

2. Description of the Related Art FIG. 5 is a block diagram of a conventional example (analog call monitor). The operation of the figure will be described below for a call between the mobile station MS ₁₁ and the mobile station M ₂₁ . It is assumed that the mobile units are connected to each other and the mobile unit and the call monitor are connected by a call request from the mobile unit MS ₁₁ , for example.

First, the mobile station MS₁₁Analog sent from
The audio signal is the corresponding radio base station BS ₁₁Retrieved in
After that, it is converted to a 64Kb / s PCM signal and is sent to the corresponding exchange 11.
input.

The exchange 11 distributes the inputted PCM signal from the MS ₁₁ and partly has a mixing function via the path ab.
The remaining part is sent to the telephone call trunk (TWT) 13 via the route ac and the exchange 12 to the radio base station BS ₂₁ . Therefore, the radio base station BS ₂₁ reversely converts the 64 Kb / s PCM signal into an analog voice signal and sends it to the mobile station MS ₂₁ .

The analog voice signal from the mobile station MS ₂₁ is converted into a PCM signal by the radio base station BS ₂₁ and then the exchange 12
Is sent to the mobile station MS ₁₁ via the route fg and the rest is sent to the three-way call trunk 13 via the route fh. To do.

The three-way call trunk 13 is composed of mobile units MS ₁₁ and MS _21.
Since the PCM signal of is input, mix the two PCM signals,
Since it is sent to the monitoring device 14 via the route de, it is converted into a voice signal here and, for example, the communication quality is monitored.

Next, in a digital mobile communication system adopting the VSELP system, in the case of connection to a fixed telephone network, a low speed encoded signal is usually converted into a PCM signal for connection.
However, in the case of connection between mobile units, the low-speed encoded signal is used as it is.

This is because when voice exchange is performed with a PCM signal,
This is to avoid this because conversion from VSELP → PCM → VSELP is required and it is expected that the speech deterioration due to several speech coding conversions will increase.

That is, in the digital mobile communication system,
In the case of a connection between mobile units, in order to reduce voice degradation as much as possible, voice exchange is performed by using a low-speed encoded signal different from the PCM signal transmitted in a normal exchange.

[0012]

As described above, in the digital mobile communication system adopting the VSELP method, in the case of connection between mobile units, since voice exchange is performed with a low-speed encoded signal as it is, a call monitor is required. There is a problem that the conventional method cannot.

An object of the present invention is to enable a speech monitor for a low speed encoded voice signal.

[0014]

FIG. 1 is a block diagram showing the principle of the present invention. In the figure, MS _{1 and} MS ₂ are codes for converting an input voice signal into a coded signal that is lower in speed than a PCM signal used in a fixed telephone network and extracting a voice signal from the input low speed coded signal. Mobile device having decryption means, 5,
An exchange station 6 connects the mobile stations with each other while keeping the low-speed encoded signal as it is.

Reference numerals 21 and 22 are input signal distribution means, 31 and 32 are signal conversion means for converting low-speed encoded signals into PCM signals, and 4
Is call monitoring means. Then, the low-speed coded signal transmitted from the mobile device is distributed by the corresponding input signal distribution means, and a part of the signal is connected to the partner mobile device via the partner exchange without being converted, but the remaining part is compatible. The signal converting means for converting into a PCM signal is connected to the call monitoring means.

Therefore, the call monitoring means can be used to monitor the call between the mobile units.

[0017]

According to the present invention, the input signal distribution means 21, 21 is provided to the switching center in the digital mobile communication system adopting the VSELP system.
22, a signal converting means 31 and 32 for converting a low-speed encoded signal into a PCM signal, and a call monitor means 4.

Then, the low-speed coded signal sent from the mobile unit is distributed by the corresponding input signal distribution means, and a part of the coded signal is connected as it is to the partner mobile unit via the partner exchange, but the remaining part is connected. The corresponding signal converting means converts it into a PCM signal and connects it to the call monitoring means.

As a result, the call quality between mobile units is hardly affected by the call monitor, and the call between the mobile units can be monitored through the call monitor means by, for example, drawing in to the maintenance terminal.

[0020]

FIG. 2 is a block diagram of an embodiment of the present invention (MS ₁₂ → M
S ₂₂ ), FIG. 3 is a block diagram of an embodiment of the present invention (MS ₂₂ → MS ₁₂ ).
FIG. 4 is a detailed block diagram of the call monitor of the present invention.

The operations of FIGS. 2 to 4 will be described below on the assumption that the mobile station MS ₁₂ and the mobile station MS ₂₂ carry out a call by the VSELP method via the corresponding exchanges 5 and 6. The parts described in detail above will be briefly described, and the parts of the present invention will be described in detail.

First, the switching center 5 shown in FIG. 2 includes, for example, a line switch 51 for controlling connection to the radio base station BS ₁₂ and signal converting means (hereinafter referred to as baseband devices) 30 to 32, and a switching process. And a digital switch 52 for performing.

It should be noted that one of the baseband devices 30 to 33 is
Sband devices 31, 32 are mobile units MS ₁₂, MS_{twenty two}Sent by
The VSELP coded signal is converted into a PCM signal.
It has a conversion function. However, the baseband device 30, 33
Has only the through function that outputs the input signal as it is
There is.

That is, input to the baseband devices 31 and 32.
The VSELP encoded signal is converted into a PCM signal, but the VSELP encoded signal input to the baseband devices 30 and 33 is relayed as it is.

The mobile station MS ₁₂ encodes the voice signal by the VSELP method and converts it into a coded signal of 11.2 Kb / s, and then sends it to the corresponding radio base station BS ₁₂ via the designated radio line. Therefore, the radio base station BS ₁₂ sends the received coded signal to the line switch 51 of the switching center 5.

Since the line switch 51 distributes the input coded signal to the path ac and the path ad, the former coded signal remains unconverted by the baseband device 30, and the path cb,
It is sent to the mobile station MS ₂₂ via the route bf, the route fg, the exchange 6 and the radio base station BS ₂₂ .

The latter encoded signal is converted into a PCM signal by the baseband device 31, and the route db ₁ and the route b ₁
-f ₁ and route f ₁ -g ₁ are sent to the three-way call trunk (TWT) 41.

Next, the mobile station MS ₂₂ shown in FIG. 3 converts the voice signal into a coded signal in the same manner as above, and then sends it to the corresponding radio base station BS ₂₂ via the designated radio line, The radio base station BS ₂₂ sends the received encoded signal to the exchange 6.

Therefore, the exchange 6 uses the internal line switch.
The encoded signal is sent to the exchange 5 through the 61, the baseband device 33 having the through function, and the digital switch 62. The exchange 5 transmits the coded signal from the mobile station MS ₂₂ to the line switch 51 via the digital switch 52 and the route fb, so that the line switch distributes the route bc and the route bd to the baseband device 30 and the base. It is sent to the band device 32.

Since the former baseband device 30 has a through function, the coded signal is directly transmitted to the radio base station BS ₁₂
Is sent to the mobile station MS ₁₂ via. Further, since the latter baseband device 32 has a conversion function, the route eb ₂ ,
Three-way call trunk (TWT) 4 via route b ₂ -f ₂ and route f ₂ -g ₂
Dispatched to 1.

Here, the line switch 51, as described above,
For mobile-to-mobile calls, a multipath connection (e.g. ac, a
-d connection). Therefore, the control part (not shown) in the line switch 51 is, for example, the mobile station MS.
Check the source number and destination number added to the call request from ₁₂ .

In the case of a call between mobile units, the baseband device having the conversion function and the baseband device having the through function are connected, and the baseband device of the former is used as a three-party call trunk and the baseband of the latter is used. The device is controlled by software so that it is connected to the called number.

Now, as shown in FIG. 4, a three-party call trunk
The PCM signals output from the (TWT) 41 from the mobile station MS ₁₂ and the mobile station MS ₂₂ are sent to the supervisory control station 43 via the digital switch 52. The supervisory control station converts it into a voice signal via the data link interface 431 and the test speech path device 432, and monitors the call with the handset 433.

That is, it becomes possible to monitor a call in a call between mobile units of a digital mobile communication system. In addition, since the switching center performs multipath connection by software control, it becomes possible to monitor the call while maintaining the connection and the quality of the call during the call.

[0035]

As described in detail above, according to the present invention, it is possible to monitor a speech for a low-speed encoded voice signal.

[Brief description of drawings]

FIG. 1 is a principle configuration diagram of the present invention.

FIG. 2 is a configuration diagram (MS ₁₂ → MS ₂₂ ) of an embodiment of the present invention.

FIG. 3 is a configuration diagram (MS ₂₂ → MS ₁₂ ) of an embodiment of the present invention.

FIG. 4 is a detailed configuration diagram of a call monitor of the present invention.

FIG. 5 is a block diagram of a conventional example (analog call monitor).
Is.

[Explanation of Codes] 21, 22 Input Signal Distribution Means 31, 32 Coded Signal Conversion Means 4 Call Monitor Means 5, 6 Switching Stations MS ₁ , MS ₂ Mobile Stations

Claims (1)

[Claims] 1. A coding / decoding means for converting an input voice signal into a coded signal at a speed lower than that of a PCM signal used in a fixed telephone network and for extracting a voice signal from the input low speed coded signal. A digital mobile communication system having mobile units (MS ₁ , MS ₂ ) and switching stations (5, 6) connecting the mobile units with the low-speed encoded signal as they are, When monitoring a telephone call, an input signal distribution means (21, 22) and a signal conversion means (31, 32) for converting a low speed encoded signal into a PCM signal are provided to the exchange.
And a call monitor means (4) are provided, and the low-speed encoded signal transmitted from the mobile station is distributed by the corresponding input signal distribution means, and a part of the signal is not converted and is transmitted to the other mobile station via the other exchange. The remaining part is converted into a PCM signal by a corresponding signal conversion means and connected to the call monitor means, and the call monitor means is used to monitor a call between mobile units. A call monitor system characterized by.