JP2010219658A - Radio communication system and radio communication terminal - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a radio communication system capable of eliminating the time of silence generated by handover immediately after speech communication is started, and to provide a radio communication terminal. <P>SOLUTION: The radio communication system cannot conduct handover after shifting to a calling state in response to a speech communication request until shifting to a speech communication state by a response to the calling. In a calling side terminal 1a or a called side terminal 1b, a CPU 30 detects the deterioration of radio communication quality in the calling state, and when the deterioration of the radio communication quality is detected, the handover is conducted by a communication control part 31 immediately after shifting to the speech communication state in the terminal wherein if the decline is detected. While the handover is conducted, the CPU 30 instructs the calling side terminal to output first voice and a voice control part 33 outputs the first voice in the calling side terminal. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a radio communication system and a radio communication terminal that perform handover in a call state.

  2. Description of the Related Art Conventionally, in a wireless communication system using mobile terminals such as a mobile phone and a PHS (Personal Handyphone System), communication between mobile terminals is performed via base stations in the vicinity of each terminal. At this time, if the radio wave condition between any one of the communicating terminals and the base station deteriorates, the communication quality cannot be kept good. For this reason, a process called handover is performed in which the communication destination is switched to a base station with a better radio wave condition.

  For example, in PHS, it takes several seconds to several tens of seconds from the start to the end of the handover. However, while the handover is being executed, the voice of the call is interrupted and is in a silent state. Nevertheless, the conversation was interrupted. Therefore, a method for reducing the silent time has been proposed. For example, Patent Document 1 discloses that the silence time when audio data is interrupted is shortened by accumulating audio data for a predetermined time in a memory and reproducing the data with a time difference.

Japanese Patent Laid-Open No. 2001-45560

  By the way, in PHS, handover is not performed in the call state until the callee terminal responds to the call request from the caller terminal, and the handover is started after the callee terminal responds and shifts to the call state. It is a mechanism to do. Therefore, if the called or calling terminal moves in a direction in which the radio wave from the base station weakens before the called terminal responds, the handover is started immediately after the response, and the silent time There was a risk of occurrence.

  At this time, the user of the calling side terminal tries to start the conversation because the RBT (Ringing Back Tone, ringing tone) has stopped, but no response is obtained from the called side terminal with no sound. As described above, when the radio wave state deteriorates in the calling state, a silent time occurs immediately after the transition to the calling state, and thus the conversation cannot be started smoothly. Even with the method of Patent Document 1, the sound data is not stored immediately after the start of the call, and therefore silent time occurs.

  An object of the present invention is to provide a radio communication system and a radio communication terminal that can eliminate the silent time that occurs due to a handover immediately after the start of a call.

  The wireless communication system according to the present invention is a wireless communication system in which a handover is not possible after a transition to a call state in response to a call request until a transition to the call state is made by a response to the call. In the call-side terminal, when detecting a decrease in radio communication quality in the call state, and when the detection means detects a decrease in radio communication quality, immediately after the detected terminal has entered the call state A communication control means for executing a handover, a call control means for instructing the calling side terminal to output a first voice while a handover is being executed by the communication control means, and the calling side Voice output means for outputting the first voice at a terminal.

  The call control means instructs the callee terminal to output a second voice while the communication control means is executing a handover, and the voice output means It is preferable to output the second sound at the terminal.

  Moreover, it is preferable that the said voice output means outputs the same sound as the ringing sound output in the said calling state as said 1st sound.

  Further, it is preferable that the call control means transmits a message instructing start and stop of voice output from a terminal executing the handover to a call partner terminal.

  In addition, the wireless communication terminal according to the present invention is a wireless communication terminal that operates in a wireless communication system in which handover is not possible after transitioning to a call state in response to a call request until transitioning to a call state by a response to the call. Then, when the call request is made and the call state is entered, a detection unit that detects a decrease in wireless communication quality, and when the detection unit detects a decrease in wireless communication quality, the call state is entered. A communication control means for executing a handover immediately after that, and when the handover is executed by the communication control means, a first voice is output to the calling terminal that has made the call request at the start of the handover. A paging system that transmits a message instructing start and transmits a message instructing output stop of the first voice at the end of the handover. And means, the.

  The radio communication terminal according to the present invention preferably further comprises audio output means for outputting the second audio while the handover is being executed by the communication control means.

  The wireless communication terminal according to the present invention is a wireless communication terminal that operates in a wireless communication system that cannot perform handover after transitioning to a call state in response to a call request, until transitioning to a call state by a response to the call, When detecting the deterioration of wireless communication quality when the call request is made and the call state is established, and when the detection means detects a decrease in wireless communication quality, immediately after the transition to the call state Communication control means for executing a handover, and audio output means for outputting a first audio while the handover is being executed by the communication control means.

  In addition, when the handover is executed by the communication control unit, the radio communication terminal according to the present invention outputs a second voice to the called terminal that has received the call request at the start of the handover. It is preferable to further include a call control means for transmitting a message for instructing the start and transmitting a message for instructing the output stop of the second voice at the end of the handover.

  According to the present invention, it is possible to eliminate the silent time caused by the handover immediately after the start of the call.

It is the schematic which shows the structure of the radio | wireless communications system which concerns on embodiment of this invention. 1 is an external perspective view of a PHS terminal according to an embodiment of the present invention. It is a block diagram which shows the function of the PHS terminal which concerns on embodiment of this invention. It is a sequence diagram which shows the flow of a process in the callee side terminal and switching origin base station which concern on embodiment of this invention. It is a sequence diagram which shows the flow of a process in the callee side terminal and switching destination base station which concern on embodiment of this invention. It is a sequence diagram which shows the flow of a process in the calling side terminal and base station which concern on embodiment of this invention.

  Hereinafter, an example of a preferred embodiment of the present invention will be described. In the present embodiment, the PHS terminal 1 and its communication system will be described as an example of the wireless communication terminal and the wireless communication system. The wireless communication terminal and the wireless communication system of the present invention are not limited to this. For example, a mobile phone or a PDA (Personal Digital) may be used as long as it does not perform a handover during a call and performs a handover after a transition to a call state. In addition to Assistant), the present invention can be applied to various wireless communication terminals and wireless communication systems such as a navigation device and a personal computer having a communication function, and a communication module connected thereto.

  FIG. 1 is a schematic diagram illustrating a configuration of a wireless communication system according to the present embodiment. The plurality of terminals 1 (1a, 1b) communicate with their neighboring base stations and are connected to each other via a public communication network.

  Here, the calling side terminal 1a of the call request communicates with the base station 100, and the called side terminal 1b communicates with the switching source base station 200. At this time, if the called terminal 1b moves away from the switching source base station 200, the radio wave becomes weak and the reception quality deteriorates. Then, the called terminal 1b executes a handover immediately after entering a call state in response to a call request, and establishes communication with the switching destination base station 300 having strong radio waves.

  FIG. 2 is an external perspective view of the PHS terminal 1 (wireless communication terminal) according to the present embodiment. Note that FIG. 2 shows a form of a so-called foldable terminal, but the form of the wireless communication terminal according to the present invention is not limited to this. For example, a sliding type in which one casing is slid in one direction from a state in which both casings are overlapped, or a rotary type in which one casing is rotated around an axis along the overlapping direction ( Turn type), or a type (straight type) in which the operation unit and the display unit are arranged in one housing and does not have a connecting unit.

  The PHS terminal 1 includes an operation unit side body 2 and a display unit side body 3. The operation unit side body 2 includes an operation unit 11 and a microphone 12 to which a voice uttered by a user of the PHS terminal 1 is input on the surface unit 10. The operation unit 11 includes a function setting operation button 13 for activating various functions such as various setting functions, a telephone book function, and a mail function, and an input operation button 14 for inputting numbers of telephone numbers, mail characters, and the like. , And a determination operation button 15 for performing determination and scrolling in various operations.

  The display unit side body 3 includes a display unit 21 for displaying various types of information on the surface unit 20 and a receiver 22 for outputting the voice of the other party of the call.

  Further, the upper end portion of the operation unit side body 2 and the lower end portion of the display unit side body 3 are connected via a hinge mechanism 4. Further, the PHS terminal 1 relatively rotates the operation unit side body 2 and the display unit side body 3 which are connected via the hinge mechanism 4, so that the operation unit side body 2 and the display unit side body 3 are rotated. The body 3 can be in an open state (open state), or the operation unit side body 2 and the display unit side body 3 can be folded (folded state).

  FIG. 3 is a block diagram showing functions of the PHS terminal 1 according to the present embodiment. The PHS terminal 1 includes an operation unit 11, a display unit 21, a CPU 30 (detection unit, call control unit), a communication control unit 31 (communication control unit), an antenna 32, and an audio control unit 33 (audio output unit). A microphone 12, a receiver 22, and a memory 34.

  The CPU 30 controls the entire PHS terminal 1, and performs predetermined control on the display unit 21, the communication control unit 31, the voice control unit 33, and the like, for example. Further, the CPU 30 receives input from the operation unit 11 or the like and executes various processes. Then, the CPU 30 controls the memory 34 to execute reading of various programs and data and writing of data when executing processing.

  In the present embodiment, the CPU 30 measures the strength of received radio waves (received electric field strength) from the base station as an index indicating wireless communication quality. When the CPU 30 detects that the radio wave has weakened in the call calling state and the communication quality has deteriorated, the CPU 30 executes the handover by controlling the communication control unit 31 immediately after shifting to the calling state. Further, the CPU 30 instructs the own terminal and the partner terminal to sound a pseudo ringing tone (local RBT) while executing the handover. Details of the processing will be described later (FIGS. 4 to 6).

  The communication control unit 31 communicates with an external device (base station) in a predetermined use frequency band (for example, 1.9 GHz band). Then, the communication control unit 31 demodulates the signal received from the antenna 32, supplies the processed signal to the CPU 30, modulates the signal supplied from the CPU 30, and transmits the signal from the antenna 32 to the external device. .

  The audio control unit 33 performs predetermined audio processing on the signal supplied from the communication control unit 31 under the control of the CPU 30 and outputs the processed signal to the receiver 22. The receiver 22 outputs the signal supplied from the audio control unit 33 to the outside. This signal may be output from a speaker (not shown) instead of or together with the receiver 22.

  The voice control unit 33 processes a signal input from the microphone 12 according to the control of the CPU 30 and outputs the processed signal to the communication control unit 31. The communication control unit 31 performs predetermined processing on the signal supplied from the audio control unit 33 and outputs the processed signal from the antenna 32.

  The memory 34 includes, for example, a working memory and is used for arithmetic processing by the CPU 30. In addition, the memory 34 stores audio data of the local RBT (first voice and second voice). The voice control unit 33 sounds the local RBT in response to an instruction from the terminal 1 that is executing the handover. The memory 34 distinguishes and stores the voice data so that the first voice is sounded when the PHS terminal 1 is the calling party, and the second voice is sounded when the PHS terminal 1 is the called party. Also good.

  4 and 5 are sequence diagrams showing a flow of processing in the called terminal 1b according to the present embodiment. Here, a case will be described in which the communication quality between the called terminal 1b and the switching source base station 200 is lowered and the handover is performed from the switching source base station 200 to the switching destination base station 300.

  FIG. 4 is a sequence diagram showing a processing flow in the called terminal 1b and the switching source base station 200 according to the present embodiment.

  The called terminal 1b receives a call request from the calling terminal 1a from the switching source base station 200. Then, after the link channel establishment phase with the switching source base station 200, the called-side terminal 1b performs CC (Call Control, call control), RT (Radio Frequency Transmission manager, radio management), MM (Mobility Management). , A predetermined control sequence based on the mobility management) is entered, and the call state is entered. When the calling state is established, the called terminal 1b transmits a CC calling message to the calling terminal 1a via the switching source base station 200 (step S1). Then, the called terminal 1b notifies the user of the incoming call by causing the voice control unit 33 to ring a ringtone or displaying the calling user name on the display unit 21.

  Next, when the user performs a predetermined response operation, the called terminal 1b transmits a CC response message to the calling terminal 1a via the switching source base station 200 (step S2). Then, when a CC response confirmation message is received from the switching source base station 200, the call state shifts to a state where a voice call is possible.

  It is assumed that the communication quality with the switching source base station 200 is deteriorated in the calling state (between step S1 and step S2). The CPU 30 of the called terminal 1b detects this communication quality drop, and executes handover after shifting to the call state (FIG. 5).

  At this time, the called terminal 1b transmits a local RBT ringing instruction message as a CC user information message to the calling terminal 1a via the switching source base station 200 (step S3). Furthermore, the called terminal 1b causes the voice control unit 33 to ring the local RBT (step S4). As a result, it is possible to notify the user of the called terminal 1b that a call cannot be made yet.

  FIG. 5 is a sequence diagram showing a processing flow in the called terminal 1b and the switching destination base station 300 according to the present embodiment.

  The called terminal 1b executes a handover in response to the detection of a decrease in communication quality in the call state, and starts communication with the switching destination base station 300 with better communication quality. Specifically, after the link channel establishment phase, a CC response message is received from the switching destination base station 300 through a predetermined control sequence by CC, RT, and MM (step S5), thereby completing the handover.

  Since the called terminal 1b is in a state where the handover is completed and the telephone call is ready, the local RBT stop instruction message is sent to the calling terminal 1a via the switching destination base station 300 as the CC user information message. Transmit (step S6). Subsequently, the called terminal 1b stops the local RBT that has been ringed by the voice control unit 33, and switches the voice path to the network side (step S7). As a result, it is possible to notify the user of the called terminal 1b that the call is possible and to start the call smoothly.

  FIG. 6 is a sequence diagram showing a processing flow in the calling terminal 1a and the base station 100 according to the present embodiment.

  After the link channel establishment phase with the base station 100, the calling terminal 1a goes through a predetermined control sequence by CC, RT, and MM, and then receives a CC call message from the called terminal 1b via the base station 100. Is received (step S11), it shifts to the calling state. Note that the CC call message in step S11 is the one sent in step S1 (FIG. 4). When the calling state is entered, the calling terminal 1a causes the voice control unit 33 to sound an RBT to notify that the user of the called terminal 1b is being called.

  Next, the calling terminal 1a receives a CC response message from the base station 100 (step S12). Note that the CC response message in step S12 is the one transmitted in step S2 (FIG. 4). When receiving the CC response message, the calling terminal 1a stops the RBT and shifts to a call state.

  Here, when receiving the local RBT ringing instruction message as the CC user information message from the base station 100 (step S13), the calling terminal 1a rings the local RBT by the voice control unit 33 (step S14). Thereby, it can be notified to the user of the calling side terminal 1a that the telephone call cannot be made yet. Note that the CC user information message in step S13 is the one transmitted in step S3 (FIG. 4).

  Thereafter, when receiving the local RBT stop instruction message as the CC user information message from the base station 100 (step S15), the calling terminal 1a stops the local RBT that has been ringed by the voice control unit 33, and sets the voice path. Switch to the network side (step S16). As a result, it is possible to notify the user of the calling side terminal 1a that a call is possible and to start the call smoothly. Note that the CC user information message in step S15 is the one transmitted in step S6 (FIG. 5).

  As described above, according to the present embodiment, the silence time generated by the handover immediately after the start of the call is eliminated, and the local RBT is caused to ring. As a result, it is possible to reduce the uncomfortable feeling that a reply cannot be obtained from the other party of the call despite the call state.

  Further, by causing the local RBT to ring with the same voice data as the normal ringing tone in the calling state, the user is made to recognize the calling state. Therefore, there is a possibility that the user of the calling side terminal 1a can wait until the end of the handover without feeling uncomfortable.

  Further, the ringing side terminal 1b also rings the local RBT, thereby eliminating the silent time immediately after the call is made in response to the call and notifying the user of the callee terminal 1b that the call cannot be started. can do. As a result, it is possible to reduce the uncomfortable feeling that a reply cannot be obtained from the other party of the call despite the call state.

  As mentioned above, although embodiment of this invention was described, this invention is not restricted to embodiment mentioned above. The effects described in the embodiments of the present invention are only the most preferable effects resulting from the present invention, and the effects of the present invention are limited to those described in the embodiments of the present invention. is not.

  In the above-described embodiment, the case where handover is performed by the called terminal 1b has been described, but the scope of application of the present invention is not limited to this. The present invention can also be applied to a case where handover is performed at the calling terminal 1a.

  That is, if the calling terminal 1a detects a decrease in communication quality in the call state (between steps S11 and S12 in FIG. 6), the base station 1a instead of receiving a local RBT ringing instruction message in step S13. 100 to the called terminal 1b. Subsequently, the calling terminal 1a starts ringing of the local RBT by the voice control unit 33 and starts a handover process.

  After that, when the calling side terminal 1a completes the handover process in the same series of steps as in FIG. 5, an instruction message for stopping the local RBT is sent to the called side terminal 1b via the new base station that is the switching destination. While transmitting, the ringing of the local RBT at the calling terminal 1a is stopped.

  As a result, the calling side terminal 1a and the called side terminal 1b can cause the local RBT to ring in response to the local RBT ringing and stop instruction messages, thereby eliminating the silent period immediately after the start of the call due to the handover.

  In the above-described embodiment, the first voice and the second voice are stored in the memory 34 as the same local RBT as the normal ringing sound in the calling state, but the present invention is not limited to this. For example, a notification sound different from a normal ringing sound may be used. The first voice and the second voice may be different. Furthermore, the voice data to be output as the first voice or the second voice may be switched by receiving an instruction input from the user in advance.

1 PHS terminal (wireless communication terminal)
1a Calling side terminal (wireless communication terminal)
1b Called terminal (wireless communication terminal)
DESCRIPTION OF SYMBOLS 11 Operation part 12 Microphone 21 Display part 22 Receiver 30 CPU (detection means, call control means)
31 Communication control unit (communication control means)
32 Antenna 33 Voice control unit (voice output means)
34 Memory 100 Base station 200 Switching source base station 300 Switching destination base station

Claims (8)

A wireless communication system in which a handover is not possible after a transition to a call state in response to a call request until a transition to a call state is made by a response to the call,
Detecting means for detecting a decrease in wireless communication quality in the calling state in the calling terminal or the called terminal;
In the case where a decrease in wireless communication quality is detected by the detection means, in the detected terminal, communication control means for executing a handover immediately after shifting to the call state;
Call control means for instructing the calling terminal to output a first voice while handover is being executed by the communication control means;
And a voice output means for outputting the first voice at the calling terminal. The call control means instructs the called terminal to output a second voice while a handover is being executed by the communication control means,
The wireless communication system according to claim 1, wherein the voice output means outputs the second voice at the called terminal.   The radio communication system according to claim 1 or 2, wherein the voice output unit outputs the same voice as the ringing sound output in the calling state as the first voice.   The call control means transmits a message instructing start and stop of voice output from a terminal executing the handover to a partner terminal of a call. The wireless communication system according to any one of the above. A wireless communication terminal that operates in a wireless communication system that cannot be handed over until it transitions to a call state by a response to the call after transitioning to a call state in response to a call request,
Detecting means for detecting a deterioration in wireless communication quality when the call request is received and the call state is established;
A communication control means for executing a handover immediately after transition to the call state when a decrease in wireless communication quality is detected by the detection means;
When the handover is executed by the communication control means, at the start of the handover, a message instructing the start of output of the first voice is transmitted to the calling side terminal that has made the call request, And a call control means for transmitting a message instructing to stop the output of the first voice at the end of.   6. The wireless communication terminal according to claim 5, further comprising voice output means for outputting a second voice while the handover is executed by the communication control means. A wireless communication terminal that operates in a wireless communication system that cannot be handed over until it transitions to a call state by a response to the call after transitioning to a call state in response to a call request,
Detecting means for detecting a decrease in wireless communication quality when the call request is made and the call state is established;
A communication control means for executing a handover immediately after transition to the call state when a decrease in wireless communication quality is detected by the detection means;
A wireless communication terminal comprising: voice output means for outputting a first voice while the handover is executed by the communication control means.   When the handover is executed by the communication control means, at the start of the handover, a message instructing the output start of the second voice is transmitted to the called terminal that has received the call request, 8. The wireless communication terminal according to claim 7, further comprising call control means for transmitting a message instructing to stop the output of the second voice when ending.

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