JPH0730947A - Voice coding matching method between radio terminal equipments - Google Patents

Abstract

PURPOSE:To prevent a state to be talking available substantially from being changed into a talking disable state. CONSTITUTION:A radio terminal equipment 11 of coding methods A, B makes a setup request to a radio terminal equipment 13 to an exchange station 31 to set a speech line of the coding method A to the exchange station 31. The exchange station 31 sets up the line with an exchange station 32 and reports the coding method A. The exchange station 32 calls the terminal equipment 13 and reports the coding method A. The terminal equipment 13 replies the call and tries to set the speech line to the exchange station 32 by the coding method A, since no idle codec is in the exchange station 32, the coding method B is used to set a speech line. The exchange station 32 makes interruption of a codec and a revision request to the coding method B to the exchange station 31 to reset the speech line by the coding method B between the exchange station 31 and the terminal equipment 11.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a voice coding method used by both radio terminals which communicate with each other in a radio communication network in which a call between a plurality of radio terminals using a plurality of voice coding methods is performed through an exchange. Concerning how to match.

[0002]

2. Description of the Related Art For example, in a mobile communication network, as shown in FIG.
In a certain zone, mobile radio terminal 1₁, 1₂Nothing
Line base station 2₁Exchange 3 via₁Connected with and also other
Mobile terminal 1 in the zone₃, 1_FourIs a wireless base station
Two₂Exchange 3 via₂Connected to the exchange 3₁, 3₂
Are connected to each other, and wireless terminals in one zone and other zones
Wireless terminals can communicate with each other through the base station and the exchange.
It is made possible. Between the wireless terminal and the exchange
In Japan as an encoding method used for transmitting audio signals
Currently uses the VSELP method, but in the future
It is conceivable that a number of methods will be adopted. And wireless end
And select and use one of several encoding methods at the end,
Mobile communication with only one encoding method
It is possible that they are mixed in the network, and in such cases
Method of encoding the voice used for a call between two wireless terminals
The law needs to be aligned. Matching the audio coding system
The following methods have been proposed. Also wireless terminals
1₁Is the codec 4a of the voice encoding method A and the voice code
A wireless terminal 1 having a coding method B codec 4b. _Four
Is equipped with only the cordic 4b. Wireless terminal
1₁Wireless terminal 1_FourIf you want to talk to
This request signal is sent through the control line
Incoming wireless terminal 1_FourTerminal number and own terminal number
And the audio encoding method you want to use, eg A
There is. The selection of the voice coding method is, for example, a predetermined selection.
Choose from the ones with the highest ranking. This call setup request is sent to the base station 2
₁Originating exchange 3 received via₁Is the subscriber database
Source terminal 1 to source 5₁And the receiving terminal 1_FourIs that
Inquires about available encoding methods. That is, subscriber day
The database 5 contains 1 of the subscriber data for each wireless terminal.
A voice coding method that can be used as one is stored.

From this inquiry, the originating exchange 3 ₁ knows that the originating terminal 1 ₁ can use the encoding methods A and B, but the receiving terminal 1 ₄ can only use the encoding method B, and uses the encoding method. Is set to B, a request to change the encoding method from A to B is issued to the calling terminal 1 ₁ , and a call setup request is issued to the terminating exchange 3 ₂ to which the encoding method B is added.
In addition, the call line is set up between the exchanges 3 ₁ and 3 ₂ . Receiving the call setup request, the terminating exchange 3 ₂ calls the wireless terminal 1 ₄ via the base station 2 ₂ and adds the use of the encoding method B to this.

[0004] After setting the telephone line by coding method B, submitted wireless terminal 1 ₄ responds. The terminating exchange 3 ₂ disconnects the codec in its own exchange, and transmits the call signal of the calling terminal 1 ₄ from the base station 2 ₂ without passing through the codec 4
Control to transfer directly to ₁ . When this disconnection is completed, the originating / terminating exchange 3 ₂ issues a cordic disconnection request to the originating exchange 3 ₁ . The originating exchange 3 ₁ disconnects the codec, and the call signal of the originating terminal 1 ₁ is transferred to the destination originating exchange 3 ₂ without passing through it. When this Kodeikku disconnect is completed, notifies the to the terminating exchange 3 _2, the receiving terminal 1 reaches the response from ₄ sequentially through the switching station 3 _2, 3 ₁ to the calling terminal 1 _1, a transmitting terminal 1 ₁ Incoming the terminal 1 ₄ it is possible to call through a communication line by coding scheme B.

[0005] In the above description, when the mobile radio terminal and the fixed terminal of the fixed communication network carry out mutual call at each exchange, for example, VCELP is used between the mobile radio terminal and the exchange.
The PCM method is used for encoding between the exchange and the fixed terminal, but in the mutual call between the mobile radio terminals, the encoded voice is directly exchange-connected without passing through the codec at the exchange. , S / N deterioration caused by passing the cordic is prevented.

[0006]

In the speech coding matching method proposed as described above, the coding method that can be used by both wireless terminals is known before the call line is set up. In order to determine the method, if the receiving terminal can use only one encoding method as described above, it is not necessary to negotiate with the wireless receiving terminal, so that the processing is simplified. However, if both the originating wireless terminal and the terminating wireless terminal can use a plurality of voice coding schemes, after making an inquiry to the subscriber database 5, if the voice coding method is uniquely determined, then it is changed. I can't. Therefore, the following inconvenience occurs.

That is, when both the originating wireless terminal and the terminating wireless terminal can use the encoding methods A and B, the originating exchange determines the encoding method to be used and sets the call from the originating exchange. When the request and the encoding method B are sent to the terminating exchange, the codec of the terminating exchange is blocked by the encoding method B, but there is a vacancy in the encoding of the encoding method A. Although the calling wireless terminal and the receiving wireless terminal can talk using the encoding method A, they cannot talk.

[0008]

According to the present invention, the receiving side switching center tries to set up a communication line for a receiving wireless terminal according to the encoding method on the transmitting side, and if the setting cannot be made,
The call line is set by another encoding method, and the caller switching center is notified of that fact, and the caller side switching center resets the call line for the calling wireless terminal by the notified call line coding method. .

That is, in the prior art, the line setting is performed after deciding which encoding method to use, but in the present invention, the line setting is performed one after another, and if the setting cannot be performed, the setting is exchanged.

[0010]

[Embodiment] An embodiment of the present invention is applied to the communication network shown in FIG.
The case will be described as an example. First, the encoding method is either A or B.
Wireless terminal 1₁But only encoding method B
Wireless terminal 1 that cannot be used_FourWhen talking to
As described below. The processing sequence is shown in FIG. Nothing
Line terminal 1₁Is base station 2₁The call setup is performed via the exchange 3 ₁To
Request, and, for example, code according to a predetermined priority
Switch line 3 that uses encryption method A₁With
Do in the meantime.

[0011] switching station 3 ₁ receives the call setting request, performs a call setup request to the switching station 3 _2, and notifies the use of A as the coding method, also between the two exchange 3 _1, 3 ₂ Set the call line. Upon receiving the call setup request, the exchange 3 ₂ calls the wireless terminal 1 ₄ via the base station 2 ₂ and notifies that the encoding method is A. The wireless terminal 1 that received the call
_{The number 4} responds via the base station 2 _2, and since only the B encoding method can be used, the call response is sent to the exchange 3 ₂ and the call line is set by the encoding method B to respond. Upon receiving the call response, the switching center 3 ₂ knows that the communication line cannot be set up by the encoding method A and that the communication line by the encoding method B has been set up. performs line re-setting request to the exchange 3 _1. Upon receiving this request, the exchange 3 ₁ sends the coding method B to the wireless terminal 1 ₁ via the base station 2 _1.
Reconfigure the telephone line by, also performs Kodeikku disconnect control, when the disconnect is completed, notifies the Kodeikku disconnection completion signal to the switching station 3 _2.

[0012] The exchange 3 ₂ which has received the notification performs Kodeikku disconnect control, when the disconnect is completed, reaching the response from the wireless terminal 1 ₄ to the exchange 3 ₁ from the exchange 3 _2,
Further from this, the wireless terminal 1 ₁ is reached, and the wireless terminals 1 ₁ and 1 ₄
A call is made using the encoding method B through the call line with. As described above, according to the present invention, the calling wireless terminal determines a coding method, issues a call setting request, and sequentially sets the call lines by the coding method. If they are different, the call line is set by the coding method that can be used by the called wireless terminal, and this is sequentially transmitted to the calling side, and the calling line of the calling wireless terminal is set to the coding method used by the called wireless terminal. It will be reset.

[0013] coding method B only only call setup wireless terminal 1 ₄ unavailable via the base station 2 ₂ the encoding method A nor available wireless terminal 1 ₁ B and encoding method B and switching station 3 ₂ requests the setting of the communication line using the coding method B together with the request to the switching center 3 as shown in FIG. 2A.
Do between ₂ and. Receiving the call setup request, the exchange 3 ₂ notifies the exchange 3 ₁ of the call setup request and the encoding method B, and performs the exchange between the exchanges 3 ₁ and 3 ₂ .

The exchange 3 ₁ calls the wireless terminal 1 ₁ and notifies that the encoding method B is used. The wireless terminal 1 ₁ answers the call and sets up a notification line using the encoding method B. Although not shown thereafter, the wireless terminal 1 ₁
There was a response, switching station 3 ₁ issues a Kodeikku disconnection request to the switching station 3 _2, switching station 3 ₂ disconnect the Kodeikku,
Upon completion, the exchange 3 ₁ disconnects the codec, and the exchange 3 ₂ receives the completion, and a call using the encoding method B is made between the wireless terminals 1 ₁ and 1 ₄ through the call line. In this case, it is not necessary to reset the communication line, that is, the codec used.

Next, the wireless terminal 1 ₁ having the encoding methods A and B
A case in which the wireless terminal 1 ₃ having the encoding methods A and B is called will be described with reference to FIG. 2B. As in the case of FIG. 1, the wireless terminal 1 ₁ requests the exchange 3 ₁ to set up a call to the wireless terminal 1 ₃ via the base station 2 ₁ and notifies that the encoding method A is used, and it sets the communication line using the encoding method a between the switching station 3 _1. The exchange 3 ₁ requests the call exchange and the line setup to the exchange 3 ₂ and also notifies that the encoding method A is used. The exchange 3 ₂ calls the wireless terminal 1 ₃ and notifies the coding method A.

The wireless terminal 1 ₃ is call response, the encoding method A
In wishing to make a set of exchange 3 ₂ and telephone line. At this time, if the switching station 3 ₂ free Kodeikku encoding method A, thereafter the same operation as in Figure 2A. However, if there is no vacant codec of the coding method A, the wireless terminal 1 ₃ sets up the communication line using the coding method B with the exchange 3 ₂ . After this, the same processing as the setting processing of the communication line using the coding method B between the wireless terminal 1 ₄ and the exchange 3 ₂ in FIG. 1 is performed. That is, as in the case of FIG. 1, if the call lines are sequentially set and the call line of the desired coding method cannot be set between the incoming exchange 3 ₂ and the wireless terminal 1 ₃ , the coding method is performed. Instead, the call line is set and the call line up to that point is reset.

[0017]

As described above, according to the present invention, the calling line is sequentially set by the coding method initially selected by the calling wireless terminal, and the calling line between the called wireless terminal and the called switching center is set by the coding method. When it is not possible to set, the setting of the communication line whose coding method has been changed is to be reset from the receiving wireless terminal side in order. Since the coding method to be used is determined and the communication line is set up, there is no vacant codec of the coding method that has been determined at the receiving exchange station, so that there is a problem that other coding methods cannot talk to places where communication is possible. Does not occur.

[Brief description of drawings]

FIG. 1 is a diagram showing a processing sequence in the method of the present invention when the setting of a call line on the receiving side is different from the encoding method initially desired on the transmitting side.

FIG. 2 is a diagram showing a processing sequence in a state different from FIG. 1 in the method of the present invention.

FIG. 3 is a block diagram showing a schematic configuration of a mobile communication network.

FIG. 4 is a diagram showing a processing sequence of a conventional speech coding matching method.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification number Internal reference number FI Technical indication H04Q 7/30 7/38 H04B 14/04 Z 4101-5K

Claims (1)

[Claims] 1. A speech coding matching method between wireless terminals in a mobile communication network comprising a plurality of wireless terminals using a plurality of speech coding methods and a switching center for switching and connecting calls between these wireless terminals. , At the called exchange, try to set up the call line for the receiving wireless terminal according to the coding method of the calling side, and if it cannot be set, set up the call line with another coding method, and call that side. A voice coding matching method between wireless terminals, which notifies the switching center, and the calling side switching center resets the communication line for the calling wireless terminal by the notified encoding method of the communication line.