JP3100222B2 - Call monitoring system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a telephone call monitoring system used for a telephone call between mobile stations in a digital mobile communication system.

[0002] In a digital mobile communication system,
64Kb used in fixed networks from the viewpoint of effective use of radio waves
VSELP (VeP (VeP), which is 11.2 Kb / s slower than PCM coding
(ctorSum Excited Linear Prediction) method was adopted.However, when this method is used, in the case of connection between mobile stations, the method of connecting directly without changing to PCM signal as described later is suitable for telephone calls This makes it impossible to monitor calls using the conventional method.

[0003] Therefore, it is necessary to be able to monitor a speech for a low-speed encoded voice signal.

[0004]

2. Description of the Related Art FIG. 5 is a block diagram of a conventional example (an analog type call monitor). Hereinafter, the call between the mobile unit M ₂₁ and the mobile device MS _11, illustrating the operation of FIG. Incidentally, between the call monitor the mobile station and between the mobile station, for example, are connected by the call request from the mobile station MS _11.

First, the mobile station MS₁₁Analog sent from
The audio signal is output from the corresponding radio base station BS. ₁₁Taken out by
After that, it is converted to 64Kb / s PCM signal and
input.

The exchange 11 distributes the input PCM signal from the MS ₁₁ and partially has a mixing function via the path ab.
The remaining part is sent to the wireless base station BS ₂₁ via the telephone call trunk (TWT) 13 and the rest via the route ac and the exchange 12. Therefore, the radio base station BS ₂₁ transmits to the mobile station MS ₂₁ a PCM signal of 64 Kb / s then converted back to an analog audio signal.

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 converted into a PCM signal.
Although it sent to the exchange 11 via a switch 11 is partitioned in the same manner as described above, to the mobile station MS ₁₁ via path fg some, delivery rest via path fh to 3-way calling trunk 13 I do.

[0008] The three-party call trunk 13 comprises mobile stations MS ₁₁ and MS _21.
Because two PCM signals are input, two PCM signals are mixed,
Since the signal is sent to the monitoring device 14 via the path de, it is converted into a voice signal here, for example, to monitor the communication quality.

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

[0010] This is because when voice exchange is performed using PCM signals,
The conversion from VSELP to PCM to VSELP is required, and it is expected that the voice deterioration due to several voice coding conversions will be large. This is to avoid this.

That is, in a digital mobile communication system,
In the case of a connection between mobile units, in order to minimize voice deterioration, voice exchange is performed using a low-speed coded signal different from a PCM signal transmitted in a normal exchange.

[0012]

As described above, in a digital mobile communication system adopting the VSELP method, in the case of a connection between mobile stations, a voice exchange is performed with a low-speed encoded signal. There is a problem that it is impossible with the conventional method.

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 convert an input voice signal into a coded signal lower in speed than a PCM signal used in a fixed telephone network, and extract a voice signal from the input low speed coded signal. Mobile device having decoding means, 5,
Reference numeral 6 denotes an exchange which connects the mobile units with each other while maintaining the low-speed coded signal.

Reference numerals 21 and 22 denote input signal distribution means, 31 and 32 signal conversion means for converting a low-speed coded signal into a PCM signal,
Is a call monitor means. Then, the low-speed coded signal transmitted from the mobile station is distributed by the corresponding input signal distribution means, and a part of the coded signal is connected to the other mobile station via the other switching station without conversion, while the remaining part is not converted. Then, the signal is converted into a PCM signal by the signal conversion means and connected to the call monitoring means.

Therefore, it is possible to monitor the communication between the mobile devices by using the communication monitoring means.

[0017]

According to the present invention, an input signal distributing means 21 is provided to an exchange in a digital mobile communication system adopting the VSELP method.
22; signal conversion means 31 and 32 for converting low-speed coded signals into PCM signals;

Then, the low-speed coded signal transmitted from the mobile station is distributed by the corresponding input signal distribution means, and a part of the coded signal is directly connected to the partner mobile station via the partner exchange, while the remaining part is connected. The signal is converted into a PCM signal by the corresponding signal conversion means and connected to the call monitoring means.

As a result, the communication quality between the mobile units is hardly affected by the communication monitor, and the communication between the mobile units can be monitored via the communication monitoring means, for example, by connecting 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 configuration diagram of the call monitor of the present invention.

[0021] Hereinafter, the mobile station MS ₁₂ and the mobile device MS ₂₂ as a perform call on VSELP scheme through the switching center 5, 6 corresponding, for explaining the operation of FIGS. Note that the parts described in detail above will be briefly described, and the parts of the present invention will be described in detail.

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

The baseband devices 30 to 33
Mobile devices MS ₁₂, MS_{twenty two}More sent out
To convert VSELP coded signals to PCM signals.
It has a replacement function. However, baseband devices 30, 33
Has only a through function that outputs the input signal as it is.
I have.

That is, the input to the baseband devices 31 and 32
The VSELP coded signal is converted into a PCM signal, but the VSELP coded 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, converts the signal into a coded signal of 11.2 Kb / s, and transmits the signal 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 exchange 5.

Since the line switch 51 distributes the input coded signal to the path ac and the path ad, the former coded signal is not converted by the baseband device 30 and the path cb,
Route bf, path fg, switching center 6, is sent to the mobile station MS ₂₂ via the radio base station BS _22.

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

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

Therefore, the switching center 6 has an internal line switch.
A coded signal is transmitted to the exchange 5 via a baseband unit 33 having a through function and a digital switch 62. Switching station 5, digital switch 52 a coded signal from the mobile station MS _22, because the transmitted line switch 51 via path fb, the baseband unit 30 and distributes the line switch path bc, the path bd, base It is sent to the band device 32.

[0030] The former of the baseband unit 30 has a through function, encoded signal as a radio base station BS ₁₂
To the mobile station MS ₁₂ via Also, 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
Sent to 1.

Here, the line switch 51 is, as described above,
For mobile-to-mobile calls, multipath connections (for example, ac, a
-d connection). For this reason, a control unit (not shown) in the line switch 51 is, for example, a mobile unit MS.
Check the source and destination numbers added to the call request from ₁₂ .

In the case of a communication between mobile stations, a baseband apparatus having a conversion function and a baseband apparatus having a through function are connected, and the former baseband apparatus is connected to a three-party communication trunk, and the latter baseband apparatus is connected. The device is controlled by software so as to be connected to the destination number.

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

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

[0035]

As described in detail above, according to the present invention, there is an effect that a call monitor can be performed for a low-speed coded voice signal.

[Brief description of the 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 according to the present invention.

FIG. 5 is a configuration diagram of a conventional example (an analog type call monitor).
It is.

[Explanation of symbols]

21, 22 input signal distribution unit 31, 32 coded signal converting means 4 call monitor means 5,6 switching center MS _1, MS ₂ mobile

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Masanori Abe 1-17-3 Sakado, Takatsu-ku, Kawasaki City, Kanagawa Prefecture Inside Fuji Denso Co., Ltd. (56) References JP-A-63-187928 (JP, A) (58) ) Surveyed field (Int.Cl. ⁷ , DB name) H04B ⁷ /24-7/26 H04M 3/00 H04Q 7/00-7/38 H04Q 11/00-11/08

Claims (1)

(57) [Claims] An encoding / decoding means for converting an input audio signal into an encoded signal lower in speed than a PCM signal used in a fixed telephone network and extracting an audio signal from the input low-speed encoded signal. the mobile station (MS _1, MS _2), a digital mobile communication system including a mobile switching center (5,6) for connecting the mobile station mutually remains in the slow coded signal, among mobile equipment mutual When monitoring the telephone call, the switching center is provided with input signal distribution means (21, 22) and signal conversion means (31, 32) for converting low-speed coded signals into PCM signals.
And call monitoring means (4), and distributes the low-speed coded signal sent from the mobile station by the corresponding input signal distribution means, and does not convert a part of the low-speed coded signal via the other party's exchange station. The remaining part is converted to a PCM signal by the corresponding signal conversion means, connected to the call monitoring means, and the communication between the mobile devices can be monitored using the call monitoring means. A call monitoring system characterized by the following.