JP5901445B2 - Wireless communication terminal and wireless communication method - Google Patents

Description

  The present invention relates to a radio communication terminal in a mobile communication system, and more particularly to power saving of the radio communication terminal.

  Mobile communication services using various communication methods are provided by mobile communication operators. Mobile carriers are based on a plurality of communication systems such as LTE (Long Term Evolution), CDMA (Code Division Multiple Access), GSM (registered trademark) (Global System for Mobile Communications), and UMTS (Universal Mobile Telecommunication System). Service is provided.

  Since these communication systems are different from each other in the radio access system, the data transmission speed, the power consumption in the wireless communication terminal in communication, and the like are different. In particular, in recent years, high-function wireless communication terminals such as smartphones have become widespread, data communication volume has increased in response to wireless access schemes such as LTE, and various signals such as control signals are transmitted and received by wireless communication. . For this reason, power consumption associated with communication is increasing, and the possession of a battery of a wireless communication terminal has become important for users.

  Various technologies have been disclosed in order to realize power saving in a wireless communication terminal that supports a plurality of wireless communication systems, for example, the following patent documents.

  Patent Document 1 discloses a mobile communication terminal device that can smoothly communicate with each of a plurality of communication systems having different frequency bands and can save power. Patent Literature 1 sets a measurement period of a reception state of each communication method based on reception state information including a reception power value for each communication method.

  Patent Document 2 discloses a wireless area evaluation device that reports the wireless quality of each wireless communication method to the wireless area evaluation management device using any one of a plurality of wireless communication methods. Disclosure of technology that realizes immediate data reporting as much as possible. Patent Document 2 determines a policy for selecting a wireless communication method to be used on an uplink based on the importance of information to be reported and the remaining power in a wireless area evaluation apparatus.

International Publication No. 2007/080627 JP 2011-130059 A

  The current consumption that affects the power consumption of the wireless communication terminal also varies depending on the transmission power. In the wireless communication terminal, the current consumption due to transmission varies depending on the communication method and frequency band, and also varies depending on the configuration of the wireless communication terminal.

  However, since a wireless communication terminal normally selects a communication method when there is a decrease in communication quality or an instruction from a wireless base station, the selected communication method is intended to reduce power consumption as much as possible. It may not be possible. For example, in a wireless communication terminal that supports two communication methods, LTE and CDMA, when there is a wireless communication terminal in a communication environment in which power consumption of LTE is larger, communication by CDMA is sufficient, LTE communication is selected based on the communication speed or the like, and as a result, the battery of the wireless communication terminal may be greatly reduced.

  As described above, a technique for improving power saving is required in a wireless communication terminal that supports a plurality of communication methods.

  A wireless communication terminal according to an embodiment can communicate with a wireless base station corresponding to each communication method by a plurality of communication methods. The wireless communication terminal includes an acquisition unit that acquires a power level of a wireless communication signal with the wireless base station, and a current consumption that indicates a current consumption for the wireless communication terminal to perform wireless communication with the wireless base station based on the acquired power level. A calculation unit that calculates a value; and a communication method control unit that selects any communication method to be used for communication based on the calculated current consumption value.

  Preferably, the wireless communication terminal includes a storage unit for storing current consumption information indicating a correspondence relationship between a power level of a wireless signal at the time of communication and a current consumption value of the wireless communication terminal for each communication method, and calculates The unit may calculate a current consumption value based on the power level acquired by the acquisition unit and the current consumption information.

  Preferably, the communication method control unit includes a setting value storage unit that stores a threshold setting value for each communication method, and the current consumption value calculated by the calculation unit is set to the threshold value of the communication method corresponding to the current consumption value. It is good also as determining a communication system according to a comparison result compared with a setting value.

  Preferably, the communication system control unit may determine that the communication system corresponding to the current consumption value is out of service when the current consumption value exceeds a set value of the threshold.

  Preferably, the communication system control unit includes a holding unit that retains a priority order used for wireless communication for the communication system, and sequentially switches the communication system according to the priority order when the current consumption value exceeds the threshold setting value. Thus, the current consumption value may be compared with the set value of the threshold value.

  Preferably, the acquisition unit acquires a power level for each communication method during communication by a specific application, and the calculation unit consumes current based on the acquired power level for each communication method during communication by the specific application. Each value may be calculated, and the communication system control unit may preferentially select the communication system corresponding to the minimum current consumption value among the current consumption values calculated for each communication system.

  Preferably, the wireless communication terminal includes a storage unit that stores application determination information indicating an application corresponding to a specific application, and the acquisition unit performs power level for each communication method during communication by the application included in the application determination information. It is good also as acquiring.

  Preferably, the specific application may include an application that continues communication at a constant communication rate.

  Preferably, the communication method control unit is selected when a communication method that requires switching of the communication method is selected, a process for confirming the switching of the communication method with the user is performed, and a confirmation operation is received from the user. It is also possible to switch to a different communication method.

  According to the present invention, power consumption is realized by acquiring a current consumption value corresponding to the power level during communication and determining a communication method based on the current consumption.

  The above and other objects, features, aspects and advantages of the present invention will become apparent from the following detailed description of the present invention taken in conjunction with the accompanying drawings.

1 is a diagram showing a partial configuration of a mobile communication system 1 including a radio communication terminal 100. FIG. 2 is a functional block diagram showing a configuration of a wireless communication terminal 100. FIG. It is a figure which shows the correspondence of the transmission power about each communication system, and consumption current. It is a figure which shows the consumption current corresponding information. It is a figure which shows the application determination information 15. FIG. 5 is a flowchart showing an operation of the control unit 16 when the wireless communication terminal 100 is in a standby state. It is a flowchart which shows the communication system determination process at the time of communication start. It is a flowchart which shows the communication system determination process in communication.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following description, the same parts are denoted by the same reference numerals. Their names and functions are also the same. Therefore, detailed description thereof will not be repeated.

<1 Overall configuration>
Hereinafter, a wireless communication terminal 100 according to an embodiment of the present invention will be described with reference to the drawings.

  FIG. 1 is a diagram showing a configuration of a part of a mobile communication system 1 including a radio communication terminal 100.

  As shown in FIG. 1, the mobile communication system 1 includes a radio communication terminal 100, a base station 200, a base station 300, and a base station 400. In the figure, wireless communication terminals other than the wireless communication terminal 100 and wireless base stations other than the base station 200 are not shown.

  The base station 200 is a radio base station that supports LTE (Long Term Evolution).

  Base station 300 is a radio base station compatible with the UMTS (Universal Mobile Telecommunications System) system. UMTS is a third generation (3G) mobile communication technology, sometimes referred to as 3G.

  Base station 400 is a radio base station compatible with the GSM (registered trademark) (Global System for Mobile Communications) system.

  The wireless base station communicates wirelessly with wireless communication terminals in a certain range of surrounding area. The area of the certain range covered by the radio base station is called “cell”. The respective cells of the base stations 200, 300, and 400 are shown as a cell 201, a cell 301, and a cell 401 in FIG.

  When the wireless communication terminal 100 is located in each area of surrounding wireless base stations, the wireless communication terminal 100 communicates wirelessly with a wireless base station of any communication method by switching the communication method in order to save power. For example, if a wireless communication terminal that supports both LTE and 3G communication methods activates these two communication methods at the same time, there is a problem that power consumption increases. Thus, for example, in an area where LTE service is available, a wireless communication terminal performs wireless communication using LTE, and when voice communication service communication is performed, the communication method is switched to the 3G circuit switching method and the voice communication service is provided. to start.

<Configuration of 2 wireless communication terminal 100>
FIG. 2 is a functional block diagram showing the configuration of the wireless communication terminal 100. As shown in FIG.

<2.1 Overview of Wireless Communication Terminal 100>
As shown in FIG. 2, the radio communication terminal 100 includes a UMTS radio communication unit 21, a UMTS antenna 22, an LTE radio communication unit 31, an LTE antenna 32, a GSM (registered trademark) radio communication unit 41, and a GSM ( (Registered trademark) antenna 42, baseband unit 10, display unit 6, audio output unit 7, audio input unit 8, and operation unit 9.

  The UMTS wireless communication unit 21 corresponds to a communication method using UMTS. The UMTS wireless communication unit 21 includes an amplifier and the like, converts a signal from the baseband unit 10 into an antenna transmission frequency, and converts an antenna reception signal into a frequency that can be processed by the baseband unit 10.

  The UMTS wireless communication unit 21 receives, by the UMTS antenna 22, a wireless signal related to voice communication or data communication from another wireless communication terminal or a Web server connected to the Internet. The UMTS wireless communication unit 21 performs signal processing on the received signal and outputs the signal to the baseband unit 10. Further, the UMTS wireless communication unit 21 performs signal processing or the like on the transmission signal generated by the baseband unit 10, and transmits the processed transmission signal to another radio through the wireless base station through the UMTS antenna 22. Transmit to a communication terminal or a communication device connected to the Internet.

  The LTE wireless communication unit 31 corresponds to a communication method based on LTE. The LTE wireless communication unit 31 includes an amplifier or the like, converts a signal from the baseband unit 10 into an antenna transmission frequency, and converts an antenna reception signal into a frequency that can be processed by the baseband unit 10. That is, when the LTE radio communication unit 31 receives a radio signal related to data communication via the radio base station by the LTE antenna 32, the LTE radio communication unit 31 performs signal processing on the received signal and outputs the signal to the baseband unit 10. Further, the LTE wireless communication unit 31 performs signal processing or the like on the transmission signal generated by the baseband unit 10 and transmits the processed transmission signal through the LTE antenna 32.

  The GSM (registered trademark) wireless communication unit 41 corresponds to a communication method based on GSM (registered trademark), converts a signal from the baseband unit 10 into an antenna transmission frequency, and converts an antenna reception signal into a baseband unit. 10 to a frequency that can be processed. The GSM (registered trademark) wireless communication unit 41 performs signal processing on the transmission signal generated by the baseband unit 10 and transmits the processed transmission signal through the GSM (registered trademark) antenna 42.

  The display unit 6 includes a display or the like, and displays various information such as characters, symbols, and figures by being controlled by a baseband unit 10 described later.

  The audio output unit 7 includes a speaker or the like, converts audio data from the baseband unit 10 into audio, and outputs the audio to the outside.

  The audio input unit 8 includes a microphone or the like, converts audio input from the outside into audio data, and outputs the audio data to the baseband unit 10.

  The operation unit 9 includes a touch panel or the like, detects an operation from the user, and outputs the operation to the baseband unit 10.

  The baseband unit 10 includes a storage unit 13, a control unit 16, a UMTS processing unit 23, an LTE processing unit 33, and a GSM (registered trademark) processing unit 43. The baseband unit 10 includes a processor (not shown). When the processor reads and executes the program stored in the storage unit 13, the baseband unit 10 exercises the functions of the control unit 16 and the like to manage the operation of the wireless communication terminal 100 in an integrated manner.

<2.2 Configuration of baseband unit 10>
The configuration of the wireless communication terminal 100 will be described in detail.

  The storage unit 13 includes a ROM (Read Only Memory), a RAM (Random Access Memory), and the like, and stores programs and data. The storage unit 13 holds current consumption correspondence information 14 and application determination information 15 described later.

  The UMTS processing unit 23 supports communication by the UMTS system, and performs modulation processing and demodulation processing on data to be transmitted and received.

  The LTE processing unit 33 supports communication using the LTE scheme, and performs modulation processing and demodulation processing on data to be transmitted and received.

  The GSM (registered trademark) processing unit 43 corresponds to communication by the GSM (registered trademark) system, and performs modulation processing and demodulation processing on data to be transmitted and received.

  The control unit 16 controls data processing of the wireless communication terminal 100. Specifically, the control unit 16 includes a power level acquisition unit 17, a consumption current calculation unit 18, and a communication method control unit 19.

  The power level acquisition unit 17 acquires the power level (power level) of the reception signal and transmission signal during wireless communication with the base station 200 and the like. The power level acquisition unit 17 acquires the power level of the received radio signal by measuring the signal strength of the radio signal transmitted from the base station 200 or the like. Further, the radio communication terminal 100 controls the power level of the radio signal transmitted to the base station 200 and the like based on the magnitude of the power level of the received radio signal. For example, when the power level of the received radio signal is small, it is assumed that the communication quality is deteriorated and the output of the transmission signal is increased. In the radio communication terminal 100, the power level of the transmission signal is controlled by the base station 200 or the like. By transmitting information on the reception level of the radio signal from the radio communication terminal 100 in the base station 200 or the like to the radio communication terminal 100 from the base station 200 or the like, the power level at the time of transmission of the radio communication terminal 100 is controlled. The power level acquisition unit 17 acquires the power level of the received signal in the radio communication terminal 100 and the power level of the radio signal transmitted by the radio communication terminal 100 based on the control of the base station 200 and the like.

  The consumption current calculation unit 18 calculates the consumption current of the wireless communication terminal 100 when the wireless communication terminal 100 performs wireless communication with the base station 200 or the like. The consumption current calculation unit 18 calculates the consumption current based on the power level during wireless communication between the wireless communication terminal 100 and the base station 200 acquired by the power level acquisition unit 17 and the consumption current correspondence information 14. calculate.

  Based on the current consumption during communication for each communication method such as LTE, UMTS, GSM (registered trademark), the communication method control unit 19 selects which communication method is used to communicate with the base station 200 or the like. Switch the communication method according to the selected communication method. In addition, the communication system control unit 19 determines from the application determination information 15 whether communication is performed by a specific application such as voice communication at the start of communication. If the communication is based on a specific application, the communication method is determined according to the transmission power level of each communication method. These processes will be described later.

<3 Data of wireless communication terminal 100>
Next, the consumption current correspondence information 14 and the application determination information 15 stored in the storage unit 13 will be described.

<3.1 Current Consumption Information 14>
FIG. 3 shows the correspondence between transmission power and current consumption for each communication method.

FIG. 4 is a diagram showing the current consumption correspondence information 14.
FIG. 3A shows the correspondence between transmission power and current consumption in the 1750 MHz W-CDMA (Wideband Code Division Multiple Access) system. FIG. 3B shows a correspondence relationship between transmission power and current consumption in the 900 MHz band GSM (registered trademark) system.

  As shown in FIGS. 3A and 3B, the current consumption during communication of the wireless communication terminal 100 varies depending on the transmission power, but also varies depending on the communication method and the band. Further, the correspondence between transmission power and current consumption varies depending on the configuration of the terminal.

  As shown in FIGS. 3A and 3B, the current consumption increases rapidly as the transmission power increases. In the present embodiment, the current consumption threshold is set in order to switch the communication method before the current consumption suddenly increases. For example, in the 1750 MHz W-CDMA system of FIG. 3A, the current consumption threshold is set so that the current consumption is up to 200 (mA). In this case, the transmission power is allowed to about 20.0 (dBm). In the example of FIG. 3B, the current consumption threshold is set so that the current consumption is up to 500 (mA). In this case, the transmission power is allowed to about 25.0 (dBm). Of course, the threshold setting is not limited to these examples.

  The wireless communication terminal 100 holds the correspondence relationship between the transmission power and current consumption shown in FIG. 3 as current consumption correspondence information 14 shown in FIG. As shown in FIGS. 4A to 4D, the consumption current correspondence information 14 holds the correspondence between transmission power and consumption current for each communication method and band.

  In the example of FIG. 4, the communication methods are indicated as “A method” and “B method”. FIG. 4A shows the correspondence between the current consumption and the transmission power of the wireless communication terminal 100 in the 800 MHz band as the first current consumption correspondence information 14A when the communication method is “A method”. Similarly, the communication method is “A method”, and the relationship between the current consumption and the transmission power of the wireless communication terminal 100 in the 2000 MHz band is shown as second current consumption correspondence information 14B. The third consumption current correspondence information 14C is a communication method “B method”, and indicates a correspondence relationship between the consumption current and transmission power of the wireless communication terminal 100 in the 800 MHz band, and the fourth consumption current correspondence information 14D is a communication method. “B method” indicates a correspondence relationship between current consumption and transmission power of the wireless communication terminal 100 in the 900 MHz band.

  Thus, in this embodiment, since the wireless communication terminal 100 holds the current consumption correspondence information 14 and selects the communication method based on the current consumption correspondence information 14, the current consumption is compared for each communication method or band. The communication method can be selected based on the current consumption. In addition, by setting the upper limit of the current consumption value as a threshold, wireless communication due to current consumption exceeding the set value can be suppressed.

<3.2 Application determination information 15>
FIG. 5 is a diagram showing the application determination information 15.

  As shown in FIG. 5, one record of the application determination information 15 includes an application identification name, an application type, and a communication method.

  The application identification name shown in FIG. 5 indicates the name of the application. The application type shown in FIG. 5 indicates the type of communication such as whether the communication by the application is voice communication or data communication. The communication method shown in FIG. 5 is a communication method that minimizes current consumption for each application ("prioritize low current consumption") when the communication method control unit 19 determines a communication method. This indicates whether the communication method is to be prioritized (“high speed communication is prioritized”).

  When the wireless communication terminal 100 downloads a certain amount of data, such as access to a file or Web, the communication time between the wireless communication terminal 100 and the base station 200 varies depending on the communication speed for each communication method. On the other hand, in the case of an application that continues communication at a constant rate, such as voice communication or reception of real-time streaming data, the communication time is constant regardless of which communication method is used. When the wireless communication terminal 100 selects a communication method in consideration of these application types, current consumption can be minimized.

<4 Operation of Wireless Communication Terminal 100>
The operation of the wireless communication terminal 100 will be described using the drawings. In the present embodiment, the wireless communication terminal 100 executes communication system switching control during (1) standby of the wireless communication terminal 100, (2) when communication is started by an application, and (3) during communication. This will be specifically described below.

<4.1 Communication method determination processing when the wireless communication terminal 100 is on standby>
FIG. 6 is a flowchart showing the operation of the control unit 16 when the wireless communication terminal 100 is in a standby state. In this embodiment, the wireless communication terminal 100 selects one of the LTE method, the UMTS method, the GSM (registered trademark) method, and the CDMA method to perform communication with the base station 200 and the like. The wireless communication terminal 100 sequentially measures the power level of the received signal in the selected communication method, and executes the standby determination process shown in FIG.

  In step S <b> 11, the communication system control unit 19 selects a communication system based on the priority order set in advance. In the present embodiment, it is assumed that the communication system priority is given priority to a communication system with a high communication rate, and the wireless communication terminal 100 first tries communication using the LTE system. When communication using the LTE system is not performed, the wireless communication terminal 100 is set to be prioritized so as to perform communication using the UMTS system secondly and thirdly using the GSM (registered trademark) system. In step S <b> 11, when it is determined that the communication method with the higher priority is out of the service area, the communication method control unit 19 selects the communication method with the next priority. For example, when it is determined that the LTE system is out of service, the communication system control unit 19 selects the UMTS system that is the second priority. When a predetermined time (for example, several minutes) has elapsed since the communication method with a high priority is determined to be out of service area, in step S11, the communication method control unit 19 determines that the communication rate is high according to the priority. Select in order from a certain communication method.

  In step S13, the communication system control unit 19 detects a standby candidate cell corresponding to the communication system selected in step S11.

  In step S15, the power level acquisition unit 17 acquires the transmission power in the communication method selected in step S11 based on the received signal from the radio base station of the cell detected in step S13.

  In step S <b> 17, the consumption current calculation unit 18 compares the transmission power acquired in step S <b> 15 with the consumption current correspondence information 14 to calculate the magnitude of consumption current of the wireless communication terminal 100.

  In step S19, the communication system control unit 19 determines whether the current consumption value calculated in step S17 is equal to or less than a predetermined threshold value.

  If it is determined in step S19 that it is equal to or less than the predetermined threshold (step S19: YES), the process proceeds to step S21, where the communication method control unit 19 determines that the communication system selected in step S11 is in a standby state, and step The communication method selected in S11 is selected as the communication method used for communication of the wireless communication terminal 100.

  If it is determined in step S19 that the current is not less than or equal to the predetermined threshold (step S19: NO), the current consumption exceeds the allowable range and is large. The communication method control unit 19 proceeds to step S23, displays on the display unit 6 whether or not to allow the user to switch the communication method, and accepts the user's operation through the operation unit 9. After the operation for permitting by the user, the communication method control unit 19 proceeds to a process of switching the communication method according to the priority order.

  In step S23, when the operation unit 9 receives an operation that the user does not permit to switch the communication method, the communication method control unit 19 proceeds to step S21 and determines that the communication method selected by the communication method selected in step S11 is standby. This communication method is selected as a communication method used for communication of the wireless communication terminal 100.

  In step S23, when the operation allowing the user to switch the communication method is accepted in the operation unit 9 (step S23: YES), the process proceeds to step S25, where it is determined that the communication method selected in step S11 is out of range, Do not select this communication method. Through such processing, the wireless communication terminal 100 can perform communication by setting the upper limit of the current consumption to a predetermined threshold, and can realize power saving.

<4.2 Communication method determination process at the start of communication>
Next, the operation of the control unit 16 at the start of communication by an application will be described using the drawings.

  FIG. 7 is a flowchart showing communication method determination processing at the start of communication. In the present embodiment, the process of FIG. 7 is executed when an application is started in the wireless communication terminal 100 or when an application to be executed is switched.

  As shown in FIG. 7, in step S31, the communication system control unit 19 acquires information (such as an application name) related to the application to be executed.

  In step S33, the communication system control unit 19 collates information related to the application with the application determination information 15, and determines whether or not this application gives priority to low current consumption.

  As a result of the determination in step S33, if the application does not prioritize the low current consumption, or the application is not included in the application determination information 15 (step S33: “No low current consumption priority” or “No applicable application”). In step S47, the communication system control unit 19 executes necessary communication processing.

  As a result of the determination in step S33, if the application prioritizes low current consumption (step S33: “low current consumption priority”), the process proceeds to step S35, and the power level acquisition unit 17 performs all communication methods (LTE method). UMTS system, GSM (registered trademark) system), the signal reception level is acquired.

  In step S37, the power level acquisition unit 17 calculates the transmission power of the radio communication terminal 100 based on the reception level of the reception signal for each communication method.

  In step S39, the consumption current calculation unit 18 calculates the consumption current by collating with the consumption current correspondence information 14 for each communication method.

  In step S41, the communication system control unit 19 compares the current consumption values calculated for the respective communication systems in step S39, and selects the communication system that provides the minimum current consumption.

  When the communication method selected in step S41 is different from the communication method at the start of processing shown in FIG. 7, in step S43, the communication method control unit 19 switches the user to the communication method selected in step S41. Is displayed on the display unit 6 or the like, and a user operation is accepted. If the communication method selected in step S41 does not involve switching of the communication method, the process of steps S43 and S45 is skipped and the process proceeds to step S47.

  In step S43, when the wireless communication terminal 100 accepts an operation for permitting switching of the communication method (step S43: YES), the communication method control unit 19 proceeds to step S45, and the communication method selected in step S41. The process proceeds to step S47.

  In step S43, when the user does not permit the switching of the communication method (step S43: NO), the communication method control unit 19 proceeds to the process of step S47 without switching the communication method.

  In step S <b> 47, the control unit 16 performs necessary communication processing according to the communication method controlled by the communication method control unit 19.

  Thus, for an application that continues communication at a constant rate, such as voice communication or streaming data transmission / reception, for example, the wireless communication terminal 100 can select a communication method based on the amount of current consumption.

<4.3 Communication method determination process at the start of communication>
Next, the operation of the control unit 16 for executing communication system switching control during communication by an application will be described with reference to the drawings.

  FIG. 8 is a flowchart showing communication method determination processing during communication. As shown in FIG. 8, the communication method control unit 19 sequentially selects a communication method even during communication by an application.

  In step S51, the consumption current calculation unit 18 acquires a consumption current value based on the transmission power in the communication method during communication.

  In step S53, the communication system control unit 19 determines whether the current consumption value acquired in step S51 is equal to or less than a predetermined threshold value.

  If it is determined in step S53 that the value is equal to or less than the predetermined threshold (step S53: YES), the process proceeds to step S55.

  In step S55, the communication system control unit 19 maintains the communication system in communication and continues communication.

  In step S53, when it is determined that the value is not equal to or less than the predetermined threshold (step S53: NO), the communication method control unit 19 proceeds to step S57 and determines whether or not to allow the user to switch the communication method. Displayed on the display unit 6 or the like. After the operation for permitting by the user, the communication system control unit 19 proceeds to a process of switching the communication system according to the priority order of the communication system.

  In step S57, when the operation unit 9 receives an operation that the user does not permit to switch the communication method (step S57: NO), the communication method control unit 19 proceeds to step S55.

  In step S57, when the operation allowing the user to switch the communication method is accepted by the operation unit 9 (step S57: YES), the process proceeds to step S59, and the communication method control unit 19 sets the communication method in communication outside the service area. Judge that there is.

  When the wireless communication terminal 100 is determined to be out of service area in step S59, the wireless communication terminal 100 executes processing such as cell search in order to start communication using another communication method.

<5 Modification>
As described above, the wireless communication terminal 100 according to the embodiment has been described. However, the wireless communication terminal 100 is not limited to the above form, and can be modified as follows.

<5.1 Judgment method for applications that prioritize minimizing current consumption>
In the description of the above embodiment, in FIG. 7, in order to determine a specific application that minimizes current consumption, the application determination information 15 is used to previously hold a specific application as a list.

  However, the present invention is not limited to this, and it may be determined whether or not the application is to continue communication for a certain communication time based on text or the like set by the application creator and indicating the description of the application. For example, whether the application is a VoIP (Voice over Internet Protocol) application is determined from the description of the application.

<5.2 Current Consumption Value Calculation Processing of Current Consumption Calculation Unit 18>
In the description of the above embodiment, the consumption current calculation unit 18 has been described as calculating the consumption current of each communication method with reference to the consumption current correspondence information 14.

  Not limited to this, a function having current consumption and transmission power as variables is stored for each communication method and band, and based on the transmission power acquired by the power level acquisition unit 17 and the above function, the current consumption May be calculated.

  In the description of the above embodiment, the wireless communication terminal 100 has been described as maintaining the correspondence between transmission power and current consumption and calculating current consumption based on the transmission power. In addition, in the wireless communication terminal 100, when there is a certain correspondence between the magnitude of the power level of the received radio signal and the transmission power transmitted to the radio base station, the current consumption calculation unit 18 receives the received signal. The current consumption value may be calculated based on the received power.

<5.3 Switching communication method when current consumption exceeds threshold>
In the description of the above embodiment, in FIGS. 6 and 8, when the current consumption value exceeds the threshold setting value, the communication method is determined to be out of range (step S25 and the like).

  However, the present invention is not limited to this, and when the value of the current consumption of a certain communication method exceeds the set value of the threshold, the communication by the communication method may be turned off.

  Further, the communication method determination process described above is executed when an application is activated, and communication may be performed by a communication method based on a determination result at the time of activation until the application is terminated.

  In FIG. 6, the LTE system, the UMTS system, and the GSM (registered trademark) system are described as examples, but the present invention may be applied to the CDMA system. Specifically, in the process of FIG. 6, thirdly, a CDMA system may be used instead of GSM (registered trademark).

  The embodiment disclosed this time must be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

  The present invention can be used for a wireless communication terminal in a mobile communication system or the like.

  DESCRIPTION OF SYMBOLS 1 Mobile communication system, 6 Display part, 7 Voice output part, 8 Voice input part, 9 Operation part, 10 Baseband part, 13 Storage part, 14 Current consumption corresponding information, 15 Application determination information, 16 Control part, 17 Power Level acquisition unit, 18 Current consumption calculation unit, 19 Communication system control unit, 21 UMTS radio communication unit, 31 LTE radio communication unit, 41 GSM radio communication unit, 22 UMTS antenna, 32 LTE antenna, 42 GSM antenna, 23 UMTS processing unit 33 LTE processing unit, 43 GSM processing unit, 100 wireless communication terminal, 200, 300, 400 base station, 201, 301, 401 cell.

Claims (9)

A wireless communication terminal capable of communicating with a wireless base station corresponding to each communication method by a plurality of communication methods,
An acquisition unit that acquires a power level of a radio communication signal with the radio base station for each of the plurality of communication methods at the start of communication by an application that performs continuous communication at a communication speed within a certain range ;
At the start of communication by the application, for each of the plurality of communication methods , a consumption current value indicating a consumption current for the wireless communication terminal to perform wireless communication with the wireless base station is calculated based on the acquired power level. A calculation unit;
The start of communication by the application, of the consumption current value calculated for each of the plurality of communication systems, and a communication method control unit that preferentially selects a communication method corresponding to the minimum current consumption value, the wireless communication Terminal. The wireless communication terminal is
Wherein for each of a plurality of communication systems, comprising: a power level of the communication time of the wireless communication signals, a storage unit for storing the current consumption information indicating a correspondence relationship between the consumption current value of the wireless communication terminal,
The wireless communication terminal according to claim 1, wherein the calculation unit calculates the consumption current value based on the power level acquired by the acquisition unit and the consumption current information. The communication method control unit includes a setting value storage unit that stores a threshold setting value for each communication method,
The acquisition unit acquires a power level of a radio communication signal with the radio base station during communication by the application,
The calculation unit, during communication by the application, based on the acquired power level and the consumption current information about the communication method in use, the consumption current for the wireless communication terminal to wirelessly communicate with the wireless base station Calculate the current consumption value indicating
The communication method control unit determines that the communication method in use is out of service when the current consumption value exceeds a threshold value corresponding to the communication method in use during communication by the application. The wireless communication terminal according to claim 2 . The communication method control unit includes a holding unit that holds a priority order used for wireless communication for the plurality of communication methods,
The communication method control unit sequentially switches the communication method according to the priority order when the current consumption value exceeds a threshold setting value corresponding to the communication method in use during communication by the application. The wireless communication terminal according to claim 3 , wherein a current consumption value is compared with a set value of the threshold value. The communication method control unit executes a process of confirming switching of the communication method with the user when a communication method that requires switching of the communication method is selected, and is selected when the confirmation operation is received from the user. The wireless communication terminal according to claim 4 , wherein the wireless communication terminal is switched to another communication method. The wireless communication terminal according to any one of claims 1 to 5, wherein whether the application corresponds to an application that performs continuous communication at a communication speed within the certain range is determined from an explanatory note of the application. The wireless communication terminal according to claim 1, wherein the application that performs continuous communication at a communication speed within a certain range is an application that performs voice communication. The wireless communication terminal according to any one of claims 1 to 5, wherein the application that performs continuous communication at a communication speed within a certain range is an application that receives streaming data. A wireless communication method of a wireless communication terminal capable of communicating with a wireless base station corresponding to each communication method by a plurality of communication methods,
At the time of standby, select the communication method with the highest priority among the plurality of communication methods, acquire the power level of the wireless communication signal with the wireless base station corresponding to the selected communication method, the acquired Based on the power level, the wireless communication terminal calculates a consumption current value indicating a consumption current for wireless communication with the wireless base station, and the consumption current value is larger than a threshold corresponding to the selected communication method. Sometimes switching communication methods according to priority,
At the start of communication by an application that performs continuous communication at a communication speed within a certain range, a power level of a radio communication signal with a radio base station corresponding to each of the plurality of communication methods is acquired, and the acquired power level Based on the calculated consumption current value for each communication method, the consumption current value indicating the consumption current for the wireless communication terminal to wirelessly communicate with the wireless base station, and corresponding to the minimum consumption current value Selecting the communication method to be prioritized;
During communication by the application according to the communication method preferentially selected in the selecting step, a power level of a radio communication signal with a radio base station corresponding to the selected communication method is acquired, and based on the acquired power level The wireless communication terminal calculates a consumption current value indicating a consumption current for wireless communication with the wireless base station, and the priority is given when the consumption current value is larger than a threshold corresponding to the selected communication method. A wireless communication method comprising: switching a communication method according to a ranking.

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