JP2005244855A - Mobile communication terminal and voice pass switching method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To optimize silent time without, regardless of variations of voice pass switching timing on the side of an exchanger. <P>SOLUTION: While communication connection with a switching originating base station having a voice pass during conversation is held, the communication connection of the voice pass with a switching destination base station is carried out (steps S1, S2), and voice is detected from the received data. On the basis of the result of voice detection, the vice pass is switched from the switching originating base station to the switching destination base station (steps S4, S5). <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a mobile communication terminal and a voice path switching method.

  Conventionally, a simple mobile phone system called PHS (Personal Handyphone System) has been realized and widely used. In this system, when a mobile terminal (mobile communication terminal) moves from a communication zone of a communicating base station or communication quality deteriorates, it performs handover or channel switching to ensure higher communication quality. Can reconnect to base station, channel. When reconnection to this base station is performed, a silence period usually occurs due to the time required to switch voice paths. For the purpose of shortening the silent time, the mobile terminal has a high-speed handover function.

  FIG. 3 is a sequence diagram for explaining a conventional fast handover function. In this high-speed handover function, while maintaining the communication connection with the currently communicating base station (switching source base station), the voice path is switched by connecting to a new base station (switching base station), thereby Is shortened. For this reason, the portable terminal has a function of simultaneously communicating with a plurality of base stations (seamless terminal).

  As shown in FIG. 3, the mobile terminal performs communication connection with the switching destination base station while maintaining communication connection with the switching source base station after the fast handover is activated. Since the voice path passing through the switching destination base station can be established by releasing Layer 2 synchronization, the voice path switching timer is started at this time, and the voice path is switched from the switching source base station via this time-out time. Switch to the destination base station. On the other hand, the switching center switches the voice path between the mobile terminal from the switching source base station to the switching destination base station at its own timing. Here, since the timeout time of the voice path switching timer of the mobile terminal is set in consideration of the time required for switching of the switching center, the timing at which the switching station switches the voice path, the timing at which the mobile terminal switches the voice path, Silence time can be optimized if matches.

Further, as a method for dealing with silent time during a call, there is known a method in which voice data during a call is stored in a FIFO memory in a portable terminal, and the stored voice data is reproduced during a handover period ( For example, see Patent Document 1).
Japanese Patent Laid-Open No. 2001-45560

However, the conventional technology described above has a problem that the silent time is not optimized.
In the conventional fast handover function of FIG. 3 described above, the voice path switching timing by the voice path switching timer of the portable terminal may be well matched with the voice path switching timing of the switching station. Therefore, when the audio path is switched between the respective exchanges, the silent time varies. FIG. 4 shows a case where the voice path switching timing of the exchange is shifted before the timing of the mobile terminal. In this case, the period from the completion of the voice path switching of the exchange to the voice path switching timing of the portable terminal is an extra silent time. FIG. 5 shows a case where the voice path switching timing of the switching center is shifted later than the timing of the portable terminal. In this case, the period from when the portable terminal switches the voice path to when the exchange starts to switch the voice path is an extra silent time.

  Also, in the method of storing and using voice data during a call, the stored data is played until the handover is completed. Since there is no silence, the silent time is not substantially shortened.

  The present invention has been made in view of such circumstances, and the object thereof is a mobile communication terminal capable of optimizing the silent time without being influenced by the variation in the voice path switching timing on the exchange side. And providing a voice path switching method.

  In order to solve the above problems, the mobile communication terminal according to the present invention establishes communication connection with a switching destination base station of the voice path while maintaining communication connection with a switching source base station having a voice path during a call. Wireless communication means capable of detecting voice from received data received by the wireless communication means, and based on a result of the voice detection, from the switching source base station to the switching destination base station And a control means for switching the voice path.

  In the mobile communication terminal according to the present invention, when the voice is detected from the received data of the switching destination base station, the control means switches the voice path.

  In the mobile communication terminal according to the present invention, a timer for measuring a predetermined time is provided, and the control means starts the timer when the voice path during a call can be switched, and the time-out of the timer In this case, when the voice is not detected from the received data of the switching source base station, the voice path is switched.

  The voice path switching method according to the present invention is a voice path switching method in a mobile communication terminal comprising a radio communication means, a voice detection means, and a control means, wherein the radio communication means has a voice path during a call. A process of communicating with the switching destination base station of the voice path while maintaining a communication connection with the original base station, and a process of detecting the voice from the received data received by the wireless communication means by the voice detecting means; The control means includes a step of switching the voice path from the switching source base station to the switching destination base station based on the result of the voice detection.

  In the voice path switching method according to the present invention, the control means switches the voice path when voice is detected from the received data of the switching destination base station.

  In the voice path switching method according to the present invention, the mobile communication terminal includes a timer for measuring a predetermined time, and the timer is switched when the control unit is in a state in which a voice path during a call can be switched. The control means switches the voice path when no voice is detected from the received data of the switching source base station when the timer times out.

  ADVANTAGE OF THE INVENTION According to this invention, the voice path switching according to the present condition of an actual voice path can be performed by detecting voice from the received data from the switching source base station or the switching destination base station. As a result, the silent time can be optimized without being affected by variations in the voice path switching timing on the exchange side.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a block diagram showing a configuration of a mobile terminal 1 (mobile communication terminal) according to an embodiment of the present invention. In FIG. 1, the control unit 11 includes a CPU, a memory, and the like, and controls each unit of the mobile terminal 1. The operation unit 12 has a numeric keypad for inputting a telephone number, various function keys, and the like. The operation unit 12 outputs the input data to the control unit 11. The display unit 13 includes a display panel such as a liquid crystal display panel and a display control circuit. Display data is input from the control unit 11 to the display unit 13.

  The radio unit 14 transmits and receives radio signals to and from the base station via the antenna 15 and performs voice communication or data communication. The voice control unit 16 processes voice transmitted / received via the wireless unit 14. The microphone 17 inputs sound to the sound control unit 16 via the control unit 11. The speaker 18 receives and outputs the call voice processed by the voice control unit 16 via the control unit 11.

  The mobile terminal 1 has a function of communicating with a plurality of base stations at the same time (seamless terminal). In addition, the voice control unit 16 has a function of analyzing reception data received from the base station via the radio unit 14 and detecting sound / silence. The control unit 11 has a high-speed handover function, and controls switching of the voice path based on the voice / silence detection result of the voice control unit 16.

Next, with reference to FIG. 2, the operation of the portable terminal 1 switching the audio path will be described. FIG. 2 is a processing flow diagram relating to the voice path switching of the control unit 11.
In FIG. 2, the mobile terminal 1 is in communication with a base station (switching source base station) and is using a voice path passing through the base station. When the handover is activated, the control unit 11 starts a fast handover process (step S1).

  Next, similarly to the conventional fast handover process shown in FIG. 3, the control unit 11 performs communication connection with the switching destination base station while maintaining communication connection with the switching source base station currently communicating. When the voice path passing through the switching destination base station can be established by releasing Layer 2 synchronization, the voice path switching timer is started at this time (steps S2 and S3). Further, the voice control unit 16 analyzes the received data received from the switching source base station and the switching destination base station, detects voice / silence, and notifies the control unit 11 of the detection result.

  Next, when the voice control unit 16 detects a sound from the received data of the switching destination base station (step S4, YES), the control unit 11 is switched by the exchange so that the voice path passes through the switching destination base station. Therefore, even if the voice path switching timer has not yet timed out, the voice path is quickly switched from the switching source base station to the switching destination base station (step S5). On the other hand, when the voice control unit 16 does not detect the voice from the reception data of the switching destination base station (step S4, NO), it is confirmed whether or not the voice path switching timer has timed out (step S6).

  Next, if there is no timeout, the process returns to step S4. On the other hand, if there is a timeout, the voice control unit 16 confirms whether or not sound is detected from the received data of the switching source base station (step S7). As a result of this confirmation, if there is sound detection, the voice path switching timer has timed out, but since it can still be determined that the voice path is passing through the switching source base station, the voice path switching is waited, The process returns to step S4. On the other hand, if no sound is detected, the voice path is switched from the switching source base station to the switching destination base station (step S5).

  In the above-described embodiment, voice detection is used as voice detection, but silence detection may be used. In this case, in the above embodiment, the presence of sound detection is read as no sound detection, and the absence of sound detection is read as silence detection.

  According to the embodiment described above, by detecting the voice from each received data from the switching source base station and the switching destination base station, whether the actual call voice is still transmitted through the path via the switching source base station, Alternatively, it is recognized whether the transmission is already made through a path via the switching destination base station. As a result, since the voice path can be switched in accordance with the actual voice path, the silent time can be optimized without being affected by the variation of the voice path switching timing on the exchange side.

  In addition, when the voice path switching timer is used together and the timer times out, if the voice is not detected from the received data of the switching source base station, the voice path is switched, so the voice path is switched to the switching destination base station. However, it is possible to prevent the voice path from being switched because no voice is detected. This improves the reliability of voice path switching.

  The embodiment of the present invention has been described in detail with reference to the drawings. However, the specific configuration is not limited to this embodiment, and includes design changes and the like within a scope not departing from the gist of the present invention.

It is a block diagram which shows the structure of the portable terminal 1 (mobile communication terminal) which concerns on one Embodiment of this invention. FIG. 2 is a processing flowchart relating to voice path switching of a control unit 11 shown in FIG. 1. It is a sequence diagram for demonstrating the conventional high-speed handover function. It is a sequence diagram for demonstrating the problem of the conventional high-speed handover function. It is a sequence diagram for demonstrating the problem of the conventional high-speed handover function.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Portable terminal (mobile communication terminal) 11 ... Control part, 12 ... Operation part, 13 ... Display part, 14 ... Radio | wireless part, 15 ... Antenna, 16 ... Audio | voice control part, 17 ... Microphone, 18 ... Speaker

Claims (6)

A wireless communication means capable of establishing a communication connection with a switching destination base station of the voice path while maintaining a communication connection with a switching source base station having a voice path during a call;
Voice detection means for detecting voice from the received data received by the wireless communication means;
Control means for switching the voice path from the switching source base station to the switching destination base station based on the voice detection result;
A mobile communication terminal comprising:   The mobile communication terminal according to claim 1, wherein the control means performs switching of the voice path when voice is detected from reception data of the switching destination base station. It has a timer that keeps a predetermined time,
The control means starts the timer when it becomes possible to switch a voice path during a call, and when the timer times out, when the voice is not detected from the received data of the switching source base station, The mobile communication terminal according to claim 2, wherein voice paths are switched. A voice path switching method in a mobile communication terminal comprising wireless communication means, voice detection means, and control means,
The wireless communication means, while maintaining a communication connection with a switching source base station having a voice path during a call, a process of communicating with a switching destination base station of the voice path;
The voice detection means detecting voice from the received data received by the wireless communication means;
The control means, based on the result of the voice detection, a process of switching the voice path from the switching source base station to the switching destination base station,
A voice path switching method comprising:   5. The voice path switching method according to claim 4, wherein when the voice is detected from the received data of the switching destination base station, the control means switches the voice path. The mobile communication terminal includes a timer for measuring a predetermined time;
The control means further includes a step of starting the timer at a time when the voice path during a call can be switched.
6. The voice path switching method according to claim 5, wherein the control means switches the voice path when voice is not detected from received data of the switching source base station when the timer times out.

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