JP5565348B2 - Wireless communication apparatus and program, and wireless communication system - Google Patents

Description

  The present invention relates to a wireless communication apparatus and program, and a wireless communication system, and can be applied to, for example, a system including a mobile phone network (mobile communication network) and a mobile phone terminal.

  In a wireless communication system such as a cellular phone network, switching to another wireless system to maintain communication due to a decrease in wireless quality (communication quality) during communication in a wireless system in which a terminal (wireless communication device) is performing a voice call Sometimes. At this time, depending on the wireless method before and after switching, the terminal maintains the current communication channel while simultaneously securing the communication channel of the wireless method scheduled to be switched, and then changes the communication contents before the previous one. Opening the communication path is difficult due to the wireless characteristics. Therefore, in the conventional terminal, there is a case where the current wireless communication path is once disconnected, a new wireless communication path is set, and the communication content is switched. As a method in which this is applied to voice communication, there is a method called SRVCC (Single Radio Voice Call Continuity, see Non-Patent Document 1).

  The switching of the radio communication path in SRVCC is performed by the terminal notifying the access network side (cell phone network side) of the radio state (information relating to communication quality) with the currently communicating radio base station, and on the access network side. Based on the radio state notified from the terminal, it is determined whether or not the radio base station needs to be switched (handover).

  At this time, there is a concern that voice interruption may occur if the user switches the wireless communication path even though the terminal is using the terminal. As a conventional technique related to such a problem, there is a technique described in Patent Document 1. Japanese Patent Application Laid-Open No. 2004-133867 proposes a method for facilitating the occurrence of a handover in a silent state of voice communication as a general handover solution.

JP 2001-36936 A

3GPP (3rd Generation Partnership Project), 3GPP TS 23.216 “Single Radio Voice Call Continuity (SRVCC)”, [Online], INTERNET, [January 9, 2011 search], <URL: http: // www. 3gpp.org/ftp/Specs/html-info/23216.htm>

  However, although Patent Document 1 is configured to facilitate handover in a silent state, a method of operating handover transition parameters (radio error threshold and handover activation electric field strength) to facilitate handover in silence. Is taking. For this reason, in the technique described in Patent Document 1, it is necessary to greatly manipulate the handover transition parameter in order to sufficiently increase the effect of facilitating the occurrence of a handover in a silent state. Therefore, in the technique described in Patent Document 1, a handover occurs before the terminal sufficiently approaches the handover destination radio base station, or communication with the radio base station to which the terminal currently belongs is interrupted before the handover is performed. There was a fear. That is, in the technique described in Patent Document 1, it is possible to easily cause a handover in a terminal in a silent state, but there is a possibility that a decrease in communication quality associated with handover control may increase.

  In addition, since the technique described in Patent Document 1 is a general notation, when applied to a wireless communication system that performs handover using SRVCC, a configuration that facilitates the occurrence of a handover in a silent state cannot be realized. It was.

  In view of the above-described problems, a wireless communication apparatus and program that can suppress a decrease in communication quality associated with handover control in a wireless communication apparatus belonging to any of a plurality of wireless base stations constituting an access network, In addition, a wireless communication system is desired.

According to a first aspect of the present invention, there is provided a wireless communication apparatus belonging to any of a plurality of wireless base stations constituting an access network and capable of performing telephone communication via the wireless base station to which the access network belongs. Communication quality measuring means for measuring the communication quality with the other radio base station, and (2) determining whether the radio base station to which the radio communication apparatus currently belongs belongs to a handover from the radio base station to another radio base station. A notification means for transmitting to the access network side a notification signal to be sent to the network side; and (3) determining a voiced state or a silent state for a transmission signal and / or a received signal in the telephone communication of the wireless communication device. And (4) using the measurement result of the communication quality measurement unit and the determination result of the determination unit to determine the timing at which the notification unit transmits a notification signal. , According to the determined timing, and control means for controlling said notification means (5) the control means, in accordance with the determination result of said determination means, the adjustment unit for adjusting the measurement result of the communication quality measuring means (6) The control means determines the timing at which the notification means transmits the notification signal using the adjusted measurement result, and (7) the determination means determines which of the transmission signal and the reception signal Is determined to be silent when at least one of the transmission signal and the reception signal is sound, and (8) the adjustment unit determines that the determination means is a sound state. While the measurement result of the communication quality measuring means, the communication quality is better for the measurement result on the radio base station of the adjacent cell adjacent to the cell to which the radio base station to which the radio communication device currently belongs corresponds. In (9) The control means has a degree of goodness indicated by the measurement result after adjustment relating to the radio base station of the neighboring cell being equal to or higher than the first condition, and the radio of the belonging cell When the goodness indicated by the measurement result related to the base station is equal to or less than the second condition, it is determined that transmission of the notification signal by the notification means is started .

The wireless communication program according to the second aspect of the present invention is (1) installed in a wireless communication apparatus that belongs to one of a plurality of wireless base stations that constitute an access network and can perform telephone communication via the wireless base station to which the access network belongs. (2) a communication quality measuring means for measuring a communication quality with a radio base station around the radio communication device; and (3) another radio from the radio base station to which the radio communication device currently belongs. Notification means for transmitting to the access network side a notification signal for causing the access network side to make a determination related to handover to the base station, and (4) a transmission signal in telephone communication of the wireless communication device, and / or Determining means for determining a voiced state or a silent state for the received signal; and (5) using the measurement result of the communication quality measuring means and the determination result of the determining means, Accordance determines when knowledge means for transmitting a notification signal to determine the timing, to function as a control means for controlling the notification means, (6) said control means, in accordance with the determination result of said determination means, said communication An adjustment unit for adjusting the measurement result of the quality measurement unit; (7) the control unit determines a timing at which the notification unit transmits a notification signal using the adjusted measurement result; The determination means determines that the transmission signal and the reception signal are silent when both the transmission signal and the reception signal are silent, and determines that the transmission state is at least when one of the transmission signal and the reception signal is voice. (9) While the determination means determines that there is a sound state, among the measurement results of the communication quality measurement means, the wireless base station of the adjacent cell adjacent to the belonging cell to which the wireless base station to which the wireless communication apparatus currently belongs corresponds (10) The control means is configured so that the degree of goodness indicated by the measurement result after adjustment relating to the radio base station of the adjacent cell is the first. It is determined that transmission of a notification signal by the notification means is started when the degree of goodness indicated by the measurement result related to the radio base station of the belonging cell is equal to or less than a second condition. And

  According to a third aspect of the present invention, there is provided a radio communication system including an access network including a plurality of radio base stations, and a radio communication apparatus belonging to any radio base station and capable of performing telephone communication via the radio base station. In the above, the wireless communication device includes the wireless communication device according to the first aspect of the present invention.

  According to the present invention, it is possible to suppress a decrease in communication quality associated with handover control in a wireless communication apparatus belonging to any of a plurality of wireless base stations that constitute an access network.

It is the block diagram shown about the functional structure of the radio | wireless communication apparatus which concerns on 1st Embodiment. It is the block diagram shown about the whole structure of the radio | wireless communications system which concerns on 1st Embodiment. It is the timing chart (1) shown about the timing which starts the event concerning communication quality information notice, and the end timing in the radio communications equipment concerning a 1st embodiment. It is the timing chart (2) shown about the timing which starts the event which concerns on communication quality information notice, and the end in the radio communications equipment concerning a 1st embodiment. It is a timing chart (3) shown about the timing which starts the event concerning communication quality information notice, and the timing which ends in the radio communications equipment concerning a 1st embodiment. 10 is a timing chart showing how the notification interval of communication quality information notification is adjusted in the wireless communication apparatus according to the second embodiment.

(A) First Embodiment Hereinafter, a wireless communication apparatus and program according to the present invention and a first embodiment of a wireless communication system will be described in detail with reference to the drawings.

(A-1) Configuration of First Embodiment FIG. 2 is a block diagram illustrating an overall configuration of a wireless communication system 1 including the wireless communication device 10 of the first embodiment. In FIG. 2, the reference numerals in parentheses are used only in the second embodiment described later.

  In FIG. 2, two wireless base stations 20-1 and 20-2 are arranged in the wireless communication system 1. The radio base stations 20-1 and 20-2 accommodate radio communication apparatuses in the corresponding areas. Although not shown in FIG. 2, the radio base stations 20-1 and 20-2 are access network systems (hereinafter referred to as “access network”) for accommodating the radio communication device 10 and connecting it to the upper network. ")"). The relationship between the wireless communication device 10 and the access network corresponds to, for example, the relationship between a mobile phone terminal and a mobile phone network (mobile communication network).

  In addition, it is assumed that the areas to which the radio base stations 20-1 and 20-2 correspond are adjacent to each other and a part thereof is overlapped. In order to simplify the description, the wireless communication apparatus 10 illustrated in FIG. 2 will be described below as being currently accommodated in the wireless base station 20-1, but the wireless base station in which the wireless communication apparatus 10 is accommodated will be described. Of course, the station 20 is not limited.

  Hereinafter, an area (cell) corresponding to the radio base station 20-1 in which the radio communication device 10 is currently accommodated is referred to as “cell S”. A cell adjacent to the cell S (a cell corresponding to the radio base station 20-2) is referred to as “cell N”. For example, when the radio communication device 10 accommodated in the radio base station 20-1 in the cell S moves in the direction of the cell N, the radio communication device 10 changes from the radio base station 20-1 to the radio base station 20. -2 is changed (handover).

  In the following, the fact that the radio communication device 10 is accommodated in any one of the radio base stations 20 is also expressed as “belongs” or “enters” in a cell corresponding to the radio base station 20. Also, in the following, the fact that the radio communication device 10 is accommodated in any one of the radio base stations 20 and “departs” from the cell corresponding to the radio base station 20 means that the radio communication device 10 is out of the accommodation of the radio base station 20. It shall be expressed.

  Furthermore, in FIG. 2, although two radio base stations 20-1 and 20-2 are arranged in the radio communication system 1, the number of radio base stations 20 (number of cells arranged) is not limited. Is. In addition, here, in order to simplify the description, it is assumed that there is only one wireless communication device 10 on the wireless communication system 1, but the number of wireless communication devices 10 to be arranged is not limited. Of course.

  Furthermore, hereinafter, the wireless communication device 10 will be described as a telephone device (mobile phone terminal) that transmits and receives an encoded digital audio signal.

  And as an access network in the radio | wireless communications system 1, since the existing mobile telephone network can be applied, detailed description is abbreviate | omitted. Specifically, as an access network in the wireless communication system 1, existing LTE (Long Term Evolution), E-UTRA / E-UTRAN (Evolved Universal Terrestrial Radio Access / Evolved Universal Restorable Mobile terrestrial compatible) A telephone network or the like can be applied. Although not shown in FIG. 2, in the wireless communication system 1, the access network including the wireless base station 20 includes an existing communication control device that performs determination and control related to handover of the wireless communication device 10. It is assumed that the same components as those of the mobile phone network are included.

  In the access network in the wireless communication system 1, a configuration for performing control related to handover of the wireless communication device 10 will be described assuming that a method similar to that of the existing SRVCC (see Non-Patent Document 1) is employed. A configuration for performing control related to handover on the radio communication apparatus 10 side will be described later.

  Next, the internal configuration of the wireless communication device 10 will be described.

  FIG. 1 is a block diagram illustrating a functional configuration of the wireless communication device 10. In FIG. 1, the reference numerals in parentheses are used only in the second embodiment described later.

  The wireless communication device 10 includes a wireless quality measurement unit 11, a notification setting management unit 12, a codec processing unit 13, a silence determination unit 14, a parameter calculation unit 15, a wireless quality notification unit 16, and a wireless transmission / reception unit 17.

  The wireless communication device 10 includes, for example, a program execution configuration such as a CPU, ROM, RAM, EEPROM, and hard disk, and an information processing device having an interface for wireless communication (a configuration divided into a plurality of devices). In addition, it may be constructed by installing the wireless communication program or the like of the embodiment, and even in that case, the functional configuration can be shown as in FIG.

  Although not shown in FIG. 1, the wireless communication apparatus 10 is, for example, a microphone for allowing a user (near-end speaker) to input a voice or outputting a voice to the user (near-end speaker). Other configurations necessary for the function as a telephone device (mobile phone terminal), such as a speaker and an input means (for example, a push button) for receiving an operation from the user, are also provided.

  The wireless transmission / reception unit 17 has an interface function for wireless communication. When receiving the encoded audio data received from the radio base station 20, the radio transmission / reception unit 17 gives the data to the encoding processing unit 131. In addition, the wireless transmission / reception unit 17 sends the encoded audio data to the wireless base station 20 by the encoding processing unit 131. In addition, as the radio | wireless transmission / reception part 17, the thing similar to the existing mobile telephone terminal etc. is applicable.

  The codec processing unit 13 performs encoding processing (encoding) and decoding processing (decoding) of an audio signal that the wireless communication apparatus 10 transmits and receives in telephone communication, and includes an encoding processing unit 131 and a decoding processing unit 132. doing. As the codec processing unit 13, for example, the same one as that of an existing mobile phone terminal can be applied.

  The encoding processing unit 131 obtains audio data obtained by encoding a transmission signal (audio signal transmitted from the near end side to the far end side) transmitted by the wireless communication apparatus 10 using a predetermined encoding method (codec). is there. The decoding processing unit 132 decodes audio data of a reception signal (audio signal transmitted from the far end side to the near end side) encoded by a predetermined encoding method.

  The silence determination unit 14 determines a silence state in a transmission signal and a reception signal of telephone communication. Specifically, the silence determination unit 14 determines “silence state” when both the transmission signal and the reception signal are silent. Then, the silence determination unit 14 determines that it is “sound state” when it is not a silence state (that is, when at least one of the transmission signal and the reception signal is sound) (simply not a silence state). You may make it judge.) Note that the silence determination unit 14 is not limited to the above-described example for determining a silence state, and may be determined to be a silence state when one of the transmission signal or the reception signal is silent. The silence determination unit 14 notifies the parameter calculation unit 15 to that effect while it can be determined that there is a silence state.

  The silence determination unit 14 is not limited to the method for determining the silence period for the transmission signal and the reception signal, and various existing methods can be used. Here, the encoding processing unit 131 and the decoding processing unit 132 are used. In the following description, it is assumed that a method of determining based on the content processed in the above is adopted.

  The codec (encoding method) of the audio signal transmitted and received by the wireless communication device 10 is not limited, but here, as an example, it is assumed that AMR (Adaptive Multi-Rate) is employed. Then, a function called VAD (Voice Activity Detection) that detects a voiced section and a silent section of the transmission signal is made to correspond to the encoding processing unit 131, and based on information (VAD flag) detected by the function of the VAD, the silent section It is assumed that the transfer data rate is reduced. In this case, the silence determination unit 14 can detect the silence section of the transmission signal by the VAD flag obtained by the encoding processing unit 131. Further, in this case, the silence determination unit 14 also indicates that the frame (data) received as the received signal is a frame in which normal audio data is inserted or a silence section on the decode processing unit 132 side. It can be determined whether the frame is a silent frame (SID frame: Silence Descriptor frame), and the silent section of the received signal can be detected based on the determination result.

  The wireless quality measurement unit 11 measures predetermined items related to communication quality (wireless state) with the wireless base station 20 (wireless base stations 20 around the wireless communication device 10) that can communicate with the wireless transmission / reception unit 17. Is what you do. For example, the radio quality measurement unit 11 may measure the communication quality with each radio base station 20 by using the radio signal reception intensity in the radio transmission / reception unit 17 and the error detection rate. Note that the wireless quality measurement unit 11 does not limit the measurement method and measurement items. Then, the wireless quality measurement unit 11 gives the measurement result to the parameter calculation unit 15.

  Here, the description will be made assuming that the greater the measured value obtained as the measurement result of the wireless quality measurement unit 11, the better (higher) the better the communication quality. Here, it is assumed that the radio quality measurement unit 11 can measure the communication quality related to the radio base station 20-1 and the radio base station 20-2 while it exists in the cell S. Further, as the content measured by the wireless quality measurement unit 11, for example, the same content as that of a mobile phone terminal compatible with the existing SRVCC can be applied.

  The wireless quality notification unit 16 transmits information related to the latest measurement result by the wireless quality measurement unit 11 (hereinafter referred to as “communication quality information”) at a timing according to the control of the parameter calculation unit 15 to be described later. To the access network side (the radio base station 20 in which the radio communication apparatus 10 is currently accommodated). Note that the content of the communication quality information notified by the wireless quality notification unit 16 is, for example, information transmitted when a mobile phone terminal corresponding to the existing SRVCC requests handover determination from the mobile phone network side (for example, , Wireless measurement reports, etc.) can be applied.

  Then, the radio base station 20 that has received the communication quality information delivers the received communication quality information to a communication control apparatus (not shown) that performs determination and control related to the handover of the radio communication apparatus 10 described above. Then, in the access network, when it is determined that the radio communication device 10 is handed over to another radio base station 20 by the determination of the communication control device (not shown), the radio communication device 10 is switched to the handover destination radio. Control to be accommodated in the base station 20 is performed. In the communication system 1, the configuration for holding the communication quality information transmitted by the wireless communication device 10 and determining the accommodation destination of the wireless communication device 10 is not limited, and for example, the same as that of an existing mobile phone network You may make it use the thing similar to a structure (for example, the structure in the mobile telephone network which employ | adopted SRVCC).

  The parameter calculation unit 15 uses the measurement result by the wireless quality measurement unit 11, the definition content (described later) stored in the notification setting management unit 12, and the determination result of the silence determination unit 14, to thereby determine the wireless quality notification unit 16. Is used to determine the timing for notifying the communication quality information. Specifically, the parameter calculation unit 15 determines the start / end timing of communication quality information notification and the interval for performing communication quality information notification to the wireless quality notification unit 16. Then, the radio quality notification unit 16 performs communication quality information notification according to the control of the parameter calculation unit 15. The processing by the parameter calculation unit 15 will be described in detail in the operation description to be described later.

  The notification setting management unit 12 has a function of storing definition contents and the like necessary for processing by the parameter calculation unit 15. Specifically, the notification setting management unit 12 stores one or a plurality of definition information related to an event (hereinafter referred to as “notification event E”) that triggers the start and end of communication quality information notification in the parameter calculation unit 15. Has been. The notification event E defines, for example, the contents when the communication quality related to the cell N exceeds the communication quality related to the cell S by a certain level or when the communication quality related to the cell S falls below a certain threshold T. be able to. The notification setting management unit 12 also stores, for each notification event E, information that defines, for example, the interval and the number of times of communication quality information notification. Here, it is assumed that the notification setting management unit 12 also stores, for each notification event E, information of a parameter (hereinafter referred to as “notification interval d0”) indicating the communication quality information notification interval.

  As the notification event E, for example, one or a plurality of conditional expressions are prepared, and the parameter calculation unit 15 starts or ends the notification event E according to the calculation results (parameter calculation results) of the conditional expressions. It is defined to make a decision. When the notification event E starts and becomes active, the parameter calculation unit 15 notifies the wireless quality notification unit 16 of the fact and the notification interval d0, and starts communication quality information notification. Control is performed. When the notification event E is started and the notification interval d0 is notified, the wireless quality notification unit 16 starts an operation of repeating the communication quality information notification every notification interval d0. On the other hand, when the notification event E ends, the parameter calculation unit 15 notifies the wireless quality notification unit 16 of the fact and performs control to end the communication quality information notification. Details of the definition contents of the notification event E stored in the notification setting management unit 12 will be described in detail in the operation description to be described later.

(A-2) Operation of the First Embodiment Next, the operation of the wireless communication device 10 in the communication system 1 of the first embodiment having the above configuration will be described.

  First, it is assumed that the wireless communication device 10 appropriately measures the communication quality of the cell S to which the device belongs and the surrounding cell N by the wireless quality measurement unit 11.

  In this case, it is assumed that the notification setting management unit 12 stores information in which an event having a content corresponding to an event that triggers a handover in SRVCC (hereinafter referred to as “notification event Es”) is defined. . The event that triggers a handover in SRVCC is Reference Document 1 (3GPP, 3GPP TS 36.331 “Evolved Universal Terrestrial Radio Access (E-UTRA); Radio Resource Control (RRC); Protocol On, ], INTERNET, [Search February 9, 2011], <URL: http://www.3gpp.org/ftp/Specs/html-info/36331.htm>).

  Then, the parameter calculation unit 15 reads information (conditional expression) defined for the notification event Es from the notification setting management unit 12.

  Specifically, it is assumed that the notification event Es includes conditional expressions represented by the following expressions (1) to (4). In the notification event Es, a state in which a predetermined condition is established between the wireless communication device 10 and the cell S (hereinafter referred to as “state CS”), and the wireless communication device 10 and the cell N are in a predetermined condition. It is assumed that a state in which the relationship is established (hereinafter referred to as “state CN”) is defined. For example, the parameter calculation unit 15 defines flags (variables) corresponding to each of the state CS and the state CN, and uses each of the flags (state CS, state CN) of the wireless communication device 10. It may be managed whether or not is established.

  In the following description, the state where the wireless communication device 10 changes from a state not corresponding to the state CS (or state CN) to a state corresponding to the state CS (or state CN) is referred to as “entering” (Entering). Similarly, letting the wireless communication apparatus 10 change from a state corresponding to the state CS (or state CN) to a state that does not correspond is referred to as “leaving” from the state CS (or state CN).

  In the notification event Es, the condition (hereinafter referred to as “condition CS1”) for the wireless communication apparatus 10 to enter the state CS is defined by the following expression (1). Further, it is assumed that the condition (hereinafter referred to as “condition CS2”) that the wireless communication apparatus 10 exits from the state CS is defined by the following equation (3). Furthermore, it is assumed that the condition (hereinafter referred to as “condition CN1”) for the wireless communication device 10 to enter the state CN is defined by the following equation (2). Furthermore, it is assumed that the condition (hereinafter referred to as “condition CN2”) that the wireless communication apparatus 10 exits from the state CN is defined by the following equation (4).

Condition CS1: Ms + Hys <Thresh_S (1)
Condition CN1: Mn + Ofn-Hys> Thresh_N (2)
Condition CS2: Ms-Hys> Thresh_S (3)
Condition CN2: Mn + Ofn + Hys <Thresh_N (4)
In the above formulas (1) to (4), “Ms” is a measured value of the communication quality related to the cell S measured by the radio quality measuring unit 11. “Mn” is a measured value of the communication quality related to the cell N measured by the wireless quality measuring unit 11. Furthermore, “Hys” is a hysteresis parameter that prevents the state from fluctuating near the threshold value. Furthermore, “Thresh_S” is a threshold value for the communication quality related to the cell S in the notification event Es. Further, “Thresh_N” is a threshold for communication quality related to the cell N in the notification event Es.

  Further, “Ofn” is an offset value, and a predetermined value is set in advance in the definition information of the event Es as the initial value of Ofn. Ofn is a parameter adjusted according to the determination result of the silence determination unit 14 (in Reference Document 1, such adjustment is not performed on this Ofn). Specifically, Ofn is assumed to be defined by the following equation (5) in the notification event Es. In the following equation (5), Os is a parameter that varies according to the determination result of the silence determination unit 14, and when the determination result is a silence state, Os ≧ 0, and when the determination result is a sound state, Os <0. It shall be In the following equation (5), Ofn is an initial value, and Ofn ′ is a value after adjustment by Os.

Ofn ′ = Ofn + Os (5)
In the notification event Es, when the condition CS1 and the condition CN1 are satisfied at the same time, the notification event Es starts and becomes an active state. Furthermore, the notification event Es is defined to end (the active state is released) when either the condition CS2 or the condition CN2 is satisfied after the active state is set.

  As described above, Ofn is a parameter that varies according to the determination result of the silence determination unit 14, and therefore the determination result of the silence determination unit 14 affects the establishment of the condition CS1 and the condition CN2.

  If the determination result of the silence determination unit 14 is a silence state, the value of Ofn is adjusted to a larger value, so the value of Mn necessary for the condition CN1 to be satisfied may be a smaller value and is easily established. Become. That is, when the determination result of the silence determination unit 14 is a silence state, the condition CN1 for starting the notification event Es is relaxed.

  Thus, when the determination result of the silence determination unit 14 is a silence state, as a result of adjusting the value of Ofn, the timing at which the notification event Es starts tends to be earlier. In other words, when the determination result of the silence determination unit 14 is a silence state, as a result of adjusting the value of Ofn, the period from the start to the end of the notification event Es becomes longer.

  On the other hand, when the determination result of the sound determination unit 14 is in a sound state, the value of Ofn is adjusted to a smaller value, so that the value of Mn necessary for satisfying the condition CN1 is larger. It needs to be a value and is difficult to be established. That is, when the determination result of the sound determination unit 14 is a sound state, the condition CN1 for starting the notification event Es becomes strict.

  That is, when the determination result of the silence determination unit 14 is a sounded state, the timing of starting the notification event Es tends to be delayed as a result of adjusting the value of Ofn. In other words, when the determination result of the silence determination unit 14 is a silence state, the time from when the notification event Es starts to when it ends is shorter as a result of adjusting the value of Ofn.

  3 to 5 are graphs showing the timing at which the notification event Es starts and ends at the parameter calculation unit 15.

  3 to 5, the horizontal axis represents time, and the vertical axis represents the values of Ms and Mn.

  FIG. 3 is a graph showing the timing at which the notification event Es starts and ends when the parameter calculation unit 15 assumes that Ofn is not adjusted (that is, when Os is not added).

  In FIG. 3, the wireless communication device 10 enters the state CS when the condition CS1 is satisfied and enters the state CS before the timing ts0 from the state that does not correspond to either the state CS or the state CN. A state in which the condition CN1 is satisfied and the state CN is entered as it increases is shown. That is, in FIG. 3, CS1 and CN1 are established at the time ts0, the wireless communication device 10 enters both the state CS and the state CN, and the notification event Es starts. In FIG. 3, the value of Ms then increases, and at time te0, the condition CS2 is satisfied and the notification event Es ends.

  FIG. 4 is a graph showing the timing at which the notification event Es starts and ends when the determination result of the silence determination unit 14 is in a sound state. In FIG. 4, it is assumed that the transition states of Ms and Mn are the same. The timing ts0 and the timing te0 shown in FIG. 4 are the same as the timing in FIG.

  In FIG. 4, it is assumed that the wireless communication device 10 enters the state CS with the condition CS1 established from a state that does not correspond to either the state CS or the state CN before the timing ts0.

  After that, Mn becomes the same value as in FIG. 3 described above at the timing ts0, but Ofn is Ofn ′ adjusted by the above equation (5) (that is, a value subtracted by Os). Therefore, the value of Mn is insufficient to satisfy the condition CN1.

  FIG. 4 shows a state in which the value of Mn further increases after the timing ts0 and the condition CN1 is satisfied and the state CN is entered at the timing ts1. That is, in FIG. 4, CS1 and CN1 are established at a timing ts1 later than the timing ts0, and a notification event Es is started. In FIG. 4, the value of Ms then increases, and at the time te0, the condition CS2 is satisfied, and the notification event Es ends.

  That is, as shown in FIG. 4, Ofn is adjusted so that the timing at which CN1 is established is delayed when the determination result of the silence determination unit 14 is a sounded state. Then, in FIG. 4, the timing at which the notification event Es starts is delayed accordingly, and the period from the start of the notification event Es to the end thereof is shorter than in the case of FIG. 3.

  FIG. 5 is a graph showing the timing at which the notification event Es starts and ends when the determination result of the silence determination unit 14 is in the silence state. In FIG. 5, it is assumed that the transition states of Ms and Mn are the same. The timing ts0 and the timing te0 shown in FIG. 5 are the same as the timing in FIG. In FIG. 5, the timing ts2 indicates a timing before the timing ts0 (that is, ts2 <ts0).

  In FIG. 5, the condition CS1 is established and enters the state CS at a time before the timing ts0 and the timing ts2 from the state in which the wireless communication device 10 does not correspond to either the state CS or the state CN. Then, after that, at time ts2 before timing ts0, the condition CN1 is satisfied and the state CN is entered. As described above, Ofn is replaced with Ofn ′ adjusted by the above equation (5) (that is, a value added by Os (however, Os ≠ 0)), so that it is necessary to satisfy the condition CN1. The value of Mn may be a smaller value than when Ofn is not adjusted (in the case of FIG. 3 described above). That is, in FIG. 5, CS1 and CN1 are established at timing ts2 earlier than timing ts0, and the wireless communication device 10 enters both the state CS and the state CN, and the notification event Es starts. Then, in FIG. 5, the value of Ms increases thereafter, the condition CS <b> 2 is satisfied at the timing te <b> 0, and the notification event Es ends.

  As described above, Ofn is adjusted so that the timing at which CN1 is established is earlier when the determination result of the silence determination unit 14 is a silence state. Then, in FIG. 5, the timing at which the notification event Es starts is earlier, and the period from the start of the notification event Es to the end is longer than that in the case of FIG.

  3 to 5 exemplify the case where the condition CS2 is satisfied as an opportunity for the end of the notification event Es, but there may naturally be a case where the condition CN2 is satisfied.

(A-3) Effects of First Embodiment According to the first embodiment, the following effects can be achieved.

In the wireless communication device 10, the offset value (Ofn) for adjusting the measured value (Mn) of the communication quality related to the cell N adjacent to the cell S that currently belongs is adjusted according to the determination result of the silence determination unit 14. In other words, the wireless communication device 10 indirectly adjusts the measured value Mn of the communication quality related to the cell N according to the determination result of the silence determination unit 14. Thereby, in the radio | wireless communication apparatus 10, when the determination result of the silence determination part 14 is a silence state, the timing which the notification event Es starts is made earlier. Therefore, in the wireless communication device 10, when the determination result of the silence determination unit 14 is a silence state, the number (frequency) of communication quality information notifications is greater than that in a sound state, and as a result, the handover trigger is controlled. (E.g., facilitating handover due to a silent state rather than a voiced state) to suppress a decrease in communication quality associated with handover control. In the wireless communication device 10, the conditions used for determining the notification event Es Only the parameters used in the equations are adjusted, and the parameters included in the communication quality information notification (such as the measurement results of the wireless quality measuring unit 11) are not adjusted. As a result, the wireless communication apparatus 10 can originally suppress a decrease in communication quality associated with facilitating the occurrence of a handover in a silent state, as in the technique described in Patent Document 1.

(B) Second Embodiment Hereinafter, a wireless communication apparatus and program according to the present invention and a second embodiment of the wireless communication system will be described in detail with reference to the drawings.

(B-1) Configuration and Operation of Second Embodiment A wireless communication system 1A of the second embodiment can also be shown using FIG. In FIG. 2, the reference numerals in parentheses are used only in the second embodiment.

  The wireless communication system 1A according to the second embodiment is different from the first embodiment in that the wireless communication device 10 is replaced with the wireless communication device 10A.

  The wireless communication device 10A of the second embodiment can also be shown using FIG. In FIG. 1, the reference numerals in parentheses are used only in the second embodiment.

  The wireless communication device 10A according to the second embodiment is different from the first embodiment in that the parameter calculation unit 15 is replaced with a parameter calculation unit 15A.

  The parameter calculation unit 15A adjusts the notification interval d0 for notifying the wireless quality notification unit 16 according to the determination result of the silence determination unit 14, and sets the adjusted parameter (hereinafter referred to as “notification interval d0 ′”). This is different from the first embodiment in that the wireless quality notification unit 16 is notified.

  Note that the notification interval d0 'is adjusted as shown in the following equation (6). In Equation (6), ds is a parameter that varies according to the determination result of the silence determination unit 14, and ds ≧ 0 in the silent state and ds <0 in the voiced state.

Notification interval d0 ′ = d0 + ds (6)
That is, the parameter calculation unit 15A adjusts the notification interval d0 to a longer time (long interval) when the determination result of the silence determination unit 14 is in a sound state, and increases the notification interval d0 in the case of a silence state. It shall be adjusted to a short time (long interval).

  In addition, in the parameter calculation unit 15A, when the determination result of the silence determination unit 14 is a silent state, if the notification interval applied to the wireless quality notification unit 16 is adjusted to be shorter than that in the voiced state, The method for adjusting the notification interval is not limited. For example, the notification interval applied to the wireless quality notification unit 16 may be adjusted only in one of the sounded state and the silent state.

  FIG. 6 is a timing chart showing how the notification interval d0 is adjusted by the parameter calculation unit 15A.

  FIG. 6A is a timing chart showing the communication quality information notification timing when it is assumed that the notification interval d0 without adjustment is applied to the wireless quality notification unit 16.

  FIG. 6B shows the communication quality when the notification interval d0 ′ (where ds is not 0) adjusted when the determination result of the silence determination unit 14 is silent is applied to the wireless quality notification unit 16. It is a timing chart showing the timing of information notification. As shown in FIG. 6B, in this case, the wireless communication device 10A performs communication quality information notification at a shorter interval than when the notification interval d0 is not adjusted (in the case of FIG. 6A). It has been broken.

  FIG. 6C shows the timing of notification of communication quality information when the notification interval d0 ′ adjusted when the determination result of the silence determination unit 14 is in a voiced state is applied to the wireless quality notification unit 16. It is a timing chart. As shown in FIG. 6C, in this case, in the wireless communication device 10A, the communication quality information is transmitted at a shorter interval than when the determination result of the silence determination unit 14 is in a sound state (in the case of FIG. 6B). Notification has been made.

(B-2) Effects of Second Embodiment According to the second embodiment, the following effects can be obtained in addition to the effects of the first embodiment.

  In the wireless communication device 10A, by adjusting the value of the notification interval d0 according to the determination result of the silence determination unit 14, the frequency of performing communication quality information notification in the silent state is higher than in the voiced state. There are many. As a result, in the wireless communication device 10A, when the determination result of the silence determination unit 14 is in the silence state, the frequency of communication quality information notification is higher than in the sound state, and as a result, from the second embodiment This also makes it easy to perform a handover in a silent state.

(C) Other Embodiments The present invention is not limited to the above-described embodiments, and may include modified embodiments as exemplified below.

(C-1) In each of the above embodiments, in order to simplify the description, the cell N is the only cell adjacent to the cell S to which the wireless communication device 10 currently belongs. Of course, there may be cases where the In that case, for example, in the wireless communication device, the processing related to the notification event Es described above (determination using the conditional expressions (1) to (4) above) is performed for all adjacent cells, When the condition for starting the notification event Es is established for any of the adjacent cells, the communication quality information notification may be started. Also, for example, in the wireless communication device, any one of the neighboring cells is selected (for example, the neighboring cell with the best measurement result by the wireless quality measurement unit is selected), and the process related to the notification event Es described above is performed. Anyway.

(C-2) In each of the above embodiments, the wireless communication device has been described as a terminal that performs telephone communication. However, the wireless communication device includes a configuration that performs other data communication (for example, communication using HTTP or FTP). May be. In the silence determination unit, when only data communication is performed (for example, when an application that performs telephone communication is not activated and other applications are activated), it is assumed that there is a silence state. The determination may be performed.

(C-3) In each of the embodiments described above, the wireless communication apparatus is described as performing processing in accordance with SRVCC, so notification is made using the conditional expressions (1) to (4) above. Processing for determining the timing of starting / ending the event Es is performed. However, if the silence determination unit determines that there is a silence state, the notification event Es is activated earlier, and the frequency of the communication quality information notification is increased. May be changed as appropriate. For example, in the above equations (1) to (4), the hysteresis parameter (Hys) is used, but this may be omitted. Further, in the above equations (1) and (4), the offset value Ofn for adjusting Mn is used, but this is omitted and replaced with the parameter Os that varies according to the determination result of the silence determination unit. Alternatively, Mn may be adjusted directly. Further, in each of the above embodiments, in the above formulas (1) and (4), the offset value Ofn is adjusted for both according to the determination result of the silence determination unit. Adjustment may be omitted.

  DESCRIPTION OF SYMBOLS 1 ... Wireless communication system, 10 ... Wireless communication apparatus, 11 ... Wireless quality measurement part, 12 ... Notification setting management part, 13 ... Codec processing part, 131 ... Encoding processing part, 132 ... Decoding processing part, 14 ... Silence determination part, DESCRIPTION OF SYMBOLS 15 ... Parameter calculation part, 16 ... Radio quality notification part, 17 ... Radio transmission / reception part, 20, 20-1, 20-2 ... Radio base station, S, N ... Cell.

Claims (6)

In a wireless communication device that belongs to one of a plurality of wireless base stations that constitute an access network and is capable of telephone communication via the wireless base station to which it belongs,
Communication quality measuring means for measuring the communication quality with the wireless base stations around the wireless communication device;
A notification means for transmitting to the access network side a notification signal for causing the access network side to make a determination related to handover from the radio base station to which the radio communication device currently belongs to another radio base station;
Determining means for determining a voiced state or a silent state for a transmission signal and / or a reception signal in telephone communication of the wireless communication device;
A control unit that determines a timing at which the notification unit transmits a notification signal using the measurement result of the communication quality measurement unit and the determination result of the determination unit, and controls the notification unit according to the determined timing; Have
The control means includes
According to the determination result of the determination means, an adjustment unit for adjusting the measurement result of the communication quality measurement means,
The control means determines the timing at which the notification means transmits a notification signal using the adjusted measurement result,
The determination means determines that there is no sound when both the transmission signal and the reception signal are silent, and determines that there is a sound state when at least one of the transmission signal or the reception signal is sound,
The adjustment unit is adjacent to the cell to which the wireless base station to which the wireless communication apparatus currently belongs belongs among the measurement results of the communication quality measuring unit while the determination unit determines that the sound is present. Adjust the measurement results for the cell's radio base station to indicate better communication quality,
The control means has a good degree indicated by the measurement result after adjustment relating to the radio base station of the adjacent cell equal to or higher than the first condition, and a good degree indicated by the measurement result relating to the radio base station of the belonging cell. A wireless communication apparatus , wherein if it is equal to or less than a second condition, it is determined that transmission of a notification signal by the notification means is started . The control means, when it is determined to initiate the transmission of the notification signal according to the notification means, according to claim 1 to said notification means, and performs a setting to repeat transmission of the notification signal at a predetermined notification intervals A wireless communication device according to 1. The control means, after starting the transmission of the notification signal by the notification means, when the degree of goodness indicated by the measurement result after adjustment related to the radio base station of the adjacent cell is equal to or less than the third condition, or when a satisfactory degree indicated by the measurement result according to the radio base station of the belonging cell becomes the fourth condition above, claim 1, characterized in that to determine the stopping transmission of the notification signal according to the notification means or 2. A wireless communication device according to 2. The control unit sets the predetermined notification interval to be applied to the notification unit to a shorter interval while the determination unit determines the silent state than when the determination unit determines the sound state. The wireless communication apparatus according to claim 2 , wherein the wireless communication apparatus is a wireless communication apparatus. A computer installed in a wireless communication device that belongs to one of a plurality of wireless base stations that constitute an access network and that can perform telephone communication via the wireless base station to which the access network belongs,
Communication quality measuring means for measuring the communication quality with the wireless base stations around the wireless communication device;
A notification means for transmitting to the access network side a notification signal for causing the access network side to make a determination related to handover from the radio base station to which the radio communication device currently belongs to another radio base station;
Determining means for determining a voiced state or a silent state for a transmission signal and / or a reception signal in telephone communication of the wireless communication device;
A control unit that determines a timing at which the notification unit transmits a notification signal using the measurement result of the communication quality measurement unit and the determination result of the determination unit, and controls the notification unit according to the determined timing; To function,
The control means includes
According to the determination result of the determination means, an adjustment unit for adjusting the measurement result of the communication quality measurement means,
The control means determines the timing at which the notification means transmits a notification signal using the adjusted measurement result,
The determination means determines that there is no sound when both the transmission signal and the reception signal are silent, and determines that there is a sound state when at least one of the transmission signal or the reception signal is sound,
The adjustment unit is adjacent to the cell to which the wireless base station to which the wireless communication apparatus currently belongs belongs among the measurement results of the communication quality measuring unit while the determination unit determines that the sound is present. Adjust the measurement results for the cell's radio base station to indicate better communication quality,
The control means has a good degree indicated by the measurement result after adjustment relating to the radio base station of the adjacent cell equal to or higher than the first condition, and a good degree indicated by the measurement result relating to the radio base station of the belonging cell. A wireless communication program, which determines that transmission of a notification signal by the notification means is started when the second condition or less is satisfied . In a wireless communication system comprising an access network comprising a plurality of wireless base stations and a wireless communication apparatus belonging to any of the wireless base stations and capable of performing telephone communication via the belonging wireless base station, , wireless communication system comprising: a wireless communication device according to any one of claims 1-4.

Images