JPH10290195A - Portable wireless communication device - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To provide a portable wireless communication device which achieves low power consumption during communication and standby, prevents early consumption of a battery, and extends standby time and communication time. That is. SOLUTION: At the time of communication, an appropriate transmission power of a portable wireless communication device is determined based on a received electric field strength from a base station and a voltage of a battery 112. During standby, the timer management unit 119 turns on / off the LCD backlight 115 and the numeric keypad illumination 116.
The non-lighting control is performed. Further, at the time of standby, based on the voltage of the battery 112, switching is performed from the incoming call transmitting means using the vibrator 113a with high power consumption to the incoming call transmitting means with the ringer 114a with lower power consumption.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a portable radio communication device in a radio communication system, and more specifically, to reduce power consumption during communication and during standby in order to extend standby time and communication time. And a portable wireless communication device.

[0002]

2. Description of the Related Art Currently, portable radio communication devices include a digital portable telephone (hereinafter, referred to as PDC) and a personal handyphone (hereinafter, referred to as PHS). In general, these communication devices have a driving battery built in the main body in order to make the most of their portability. Most of these batteries are rechargeable. If the battery is consumed by communication, the battery is recharged and used. However, there is no case where a normal user carries a charger together,
When the communication device is carried outdoors, the battery cannot be charged. Therefore, when the battery is exhausted,
Communication becomes impossible.

[0003] With respect to this finite communication time, as an important specification item for evaluating the performance of the portable radio communication device, the transmission time from the partner for how long continuously from the state where the built-in rechargeable battery is charged to the maximum. `` Continuous standby time '' that indicates whether you can receive calls, and `` Continuous communication time '' that indicates how long you can talk to the other party continuously from the state where the built-in rechargeable battery is fully charged There is.
Portable wireless communication devices having longer time periods tend to be accepted by users, and when developing a mobile wireless communication device, the “continuous standby time” or “continuous communication time” while carrying
In order to extend the length of time, it is necessary to reduce the power consumption of portable wireless communication devices.

One of the methods for extending the above-mentioned time is to reduce the consumption of a built-in battery of a portable radio communication device. As a method of reducing the consumption of the built-in battery, there is a battery saving technique using a time division multiplex method as a measure for reducing power consumption during standby. The time division multiplexing method is a method generally adopted in PDC and PHS, and is as follows. The base station performs communication by intermittently repeating a period during which a signal is transmitted and a period during which nothing is transmitted. On the other hand, the portable wireless communication device is synchronized with a period in which the base station is transmitting a signal,
The power is supplied to the internal circuit to receive the transmitted signal. On the other hand, the portable wireless communication device does not supply power to the internal circuit during a period when the base station is not transmitting anything. As a result, early consumption of the built-in battery is prevented.

[0005] Further, a portable radio communication device represented by PDC or PHS can measure a received electric field strength from a base station during communication. These received electric field strengths are used to determine the distance from the base station. In other words, when the received electric field strength is strong, it can be determined that the base station is close. When the received electric field strength is weak, whether the base station exists only far away,
Alternatively, it can be determined that the place where the communication is being performed is a place that enters a blind spot of radio waves, such as behind a building. Normally, when communication is performed at a location close to the base station, the base station can obtain a sufficient reception electric field strength without increasing the transmission power from the portable wireless communication device so much.

As a countermeasure for low power consumption during communication using the reception electric field strength, there is a method of controlling the transmission power of a portable radio communication device. As a prior art relating to this transmission power control method, there is a method described in Japanese Patent Application Laid-Open No. H5-227079. The transmission power control method described in this publication is based on the information on the level of the received electric field strength and the ratio of the time change thereof (change rate of two different received electric field strengths calculated by the time difference) based on the information of the portable radio. This is a method for controlling transmission power from a communication device.

[0007]

However, the transmission power control method described in the above-mentioned conventional publication aims at reducing the power consumption during communication of the portable radio communication device, but it does not use the built-in battery. Does not take into account remaining capacity. Therefore, regardless of the remaining capacity of the built-in battery, the transmission power is controlled at the level of the received electric field strength, so that the communication quality is unnecessarily degraded or the communication is interrupted halfway. Failure occurs.

Further, at present, when a portable radio communication device makes a call (hereinafter, called a call) or when a dial key or the like is pressed (hereinafter, abbreviated as a key press), illumination of an LCD backlight or key illumination is performed. It is a known fact that a method of turning on a light and turning it off after a predetermined time is adopted in each portable wireless communication device. However, in this method, in a bright daytime, the lighting is turned on not only at the time of outgoing call but also at the time of incoming call, consuming power unnecessarily.

Therefore, an object of the present invention is to reduce the power consumption by determining the transmission power of the portable radio communication device based on the received electric field strength and the battery voltage during communication, and to reduce the power consumption during standby. In, power saving is achieved by controlling power supply to a device that performs illumination lighting on an LCD that is a display device and a numeric keypad that is a key input device, and power consumption is further reduced based on the remaining capacity of the battery voltage. It is an object of the present invention to provide a portable wireless communication device in which a standby time and a communication time are extended by switching to a small incoming call transmission means.

[0010]

Means for Solving the Problems and Effects of the Invention A first invention is a portable radio communication apparatus which is movable and wirelessly connected to a base station, wherein the base station is in communication with the base station. Receiving electric field strength measuring means for measuring the receiving electric field strength from the battery, battery voltage measuring means for measuring the battery voltage of the communication device, and transmission power for determining the transmission power of the communication device based on both the receiving electric field strength and the battery voltage Determining means,
The transmission power determination means determines transmission power so as to reduce power consumption during communication.

As described above, the first invention provides a portable radio communication device based on a value obtained by measuring a received electric field strength from a base station during communication and a value obtained by measuring a battery voltage of the portable radio communication device. Determine the transmission power. This transmission power is determined so as to reduce the power consumption during communication, that is, to reduce the power consumption when the reception electric field strength is strong or the battery voltage is low. Thus, the first aspect of the present invention can reduce power consumption during communication of the portable wireless communication device, that is, prevent early consumption of the battery voltage, and secure long-time communication.

According to a second aspect of the present invention, in the first aspect, the transmission power determining means has a reception electric field strength determination threshold value, and when the reception electric field strength is equal to or greater than the reception electric field strength determination threshold value, Regardless of the voltage, the transmission power is determined to be an arbitrary value equal to or less than the reference transmission power.

As described above, the transmission power determining means in the first invention determines the transmission power of the portable radio communication device based on the reception electric field strength and the battery voltage. Even in such a case, the transmission power cannot be reduced to a certain level or less due to the communication quality. Therefore, a second invention provides the transmission power determination means of the first invention with a reception electric field strength judgment threshold value, and when the reception electric field strength is a strong electric field equal to or higher than the reception electric field strength judgment threshold value, Irrespective of the transmission power, the transmission power is fixed to an arbitrary value equal to or lower than the reference transmission power. As a result, it is possible to reduce the power consumption during communication of the portable wireless communication device and to secure the minimum communication quality.

According to a third aspect, in the first aspect, the transmission power determining means has a reception electric field strength determination threshold value, and when the reception electric field strength is less than the reception electric field strength determination threshold value, The transmission power is determined as the reference transmission power regardless of the voltage.

As described above, the transmission power determining means in the first invention determines the transmission power of the portable radio communication device based on the reception electric field strength and the battery voltage. In some cases, communication quality must be emphasized over low power consumption. Therefore, a third invention provides the transmission power determination means in the first invention with a reception electric field strength determination threshold value, and when the reception electric field strength is a weak electric field equal to or less than the reception electric field strength determination threshold value, , The transmission power is fixed to the reference transmission power (that is, the maximum transmission power). Thus, it is possible to prevent a decrease in communication quality of the portable wireless communication device.

According to a fourth aspect of the present invention, in the first aspect, the transmission power determining means includes a first reception electric field strength determination threshold value and a second reception electric field strength determination value lower than the first reception electric field strength determination threshold value. A reception electric field strength determination threshold value, wherein the reception electric field strength is
If the value is equal to or more than the reception electric field strength determination threshold value, the transmission power is determined to be an arbitrary value equal to or less than the reference transmission power regardless of the battery voltage, and the reception field strength is determined by the first reception electric field strength judgment. If the value is less than the threshold value and is equal to or more than the second reception electric field strength determination threshold value, based on both the reception electric field strength and the battery voltage, a value is selected from a plurality of preset power values. The transmission power is determined, and when the received field strength is less than the second received field strength determination threshold, the transmission power is determined as the reference transmission power regardless of the battery voltage.

As described above, according to the fourth aspect, the transmission power determining means according to the first aspect includes the first reception field strength determination threshold value and the lower value than the first reception field strength threshold value. Of the second received electric field strength determination threshold value. When the received electric field strength is a strong electric field equal to or higher than the first received electric field strength determination threshold value, the transmission power is set to an arbitrary transmission power equal to or less than the reference transmission power regardless of the battery voltage. Transmission power) and the second
When the weak electric field is less than the reception electric field strength determination threshold value, the transmission power is fixed to the reference transmission power (maximum transmission power) irrespective of the battery voltage. If it is within the range equal to or greater than the reception electric field strength determination threshold value of 2, the transmission power is determined from a plurality of power values set in advance based on the reception electric field strength and the battery voltage. Thus, the fourth invention can reduce the power consumption during communication of the portable wireless communication device, that is, prevent the battery voltage from being quickly consumed, without deteriorating the communication quality over the entire range of the received electric field strength. , It is possible to secure long-time communication.

A fifth aspect of the present invention is a portable radio communication apparatus having a clock function, wherein the clock function includes time setting means for setting a turn-off control start time and a turn-off control end time of its own lighting function. It is characterized by the following.

As described above, the fifth invention uses the internal clock of the portable radio communication device and designates the lighting function of the portable radio communication device, that is, the time when the LCD backlight and the numeric keypad illumination are not turned on. It is. By turning off the LCD backlight and numeric keypad illumination at any time, it is possible to reduce the power consumption during standby, that is, to prevent early consumption of the battery voltage, and to prevent the portable wireless communication device from operating for a long time. Communication can be secured.

According to a sixth aspect of the present invention, the time from the light-off control start time to the light-off control end time in the time setting means in the fifth invention is set in accordance with a time period in which it is less necessary to turn on the lighting function. Features.

As described above, according to the sixth aspect of the present invention, it is not necessary to turn on the LCD backlight or the ten-key illumination by setting the time from the turn-off control start time to the turn-off control end time of the time setting means in the fifth aspect. It is set in accordance with the time from when the day rises to when it sets (hereinafter, referred to as illuminable time). This reduces power consumption during communication,
That is, early consumption of the battery voltage can be prevented, and long-term communication of the portable wireless communication device can be ensured.

A seventh invention is a portable wireless communication device which is movable and wirelessly connected to a base station, wherein a battery voltage measuring means for measuring a battery voltage of the communication device; A first incoming call transmission means for communicating that there has been communication from the base station, and a second incoming call transmission for notifying that communication has been made from the base station which consumes relatively less power than the first incoming call transmission means. Means having a battery voltage threshold for determining the battery voltage, and selection control means for controlling selection of the incoming call transmission means, wherein the selection control means has a battery voltage equal to or less than the battery voltage threshold. In the case of (1), the first incoming call transmitting means is automatically switched to the second incoming call transmitting means.

As described above, the seventh aspect of the present invention includes the first or second incoming call transmitting means when the measured battery voltage falls below a preset threshold when the first or second incoming call transmitting means is provided. The incoming call setting is switched from the means to the second incoming call transmitting means, that is, the incoming call transmitting means with lower power consumption. As a result, low power consumption during standby, that is, prevention of early consumption of the battery voltage can be prevented, and long-term communication of the portable wireless communication device can be secured.

[0024]

FIG. 1 is a diagram showing an example of a use environment of a portable radio communication device according to an embodiment of the present invention.
In FIG. 1, an example of a usage environment of a portable wireless communication device according to an embodiment of the present invention includes a portable wireless communication device 11, a wireless base station 12, a wireless communication line 13, and a wired communication network 14.
Consists of

The portable radio communication device 11 is a radio communication line 1
The communication with the other party is performed via the wireless communication base station 3, the wireless base station 12, and the wired communication network 14. At this time, the voltage of the internal battery of the portable wireless communication device 11 decreases as the communication time elapses. When the voltage of the built-in battery falls below a certain reference value, the portable wireless communication device 11 cannot operate and communication is disconnected. Therefore, in the portable wireless communication device 11, it is an important specification how long communication and standby can be performed.

FIG. 2 is a block diagram showing an example of the configuration of the portable radio communication device according to one embodiment of the present invention. FIG.
In the portable wireless communication device according to one embodiment of the present invention, a battery voltage monitoring unit 111, a battery 112, a vibrator driving unit 113, a ringer driving unit 114, an LCD backlight 115, a numeric keypad illumination 116
, A control unit 117, a radio unit 118, and a timer management unit 1.
19 is provided. Hereinafter, a control method according to the present invention will be described with reference to FIG.

(Application Control) The battery 112 is gradually discharged when the vibrator driving unit 113 or the ringer driving unit 114 is controlled when an incoming call is received, and when the LCD backlight 115 and the numeric keypad illumination 116 are turned on when the key of the other party number is depressed. Continue to wear out. The battery voltage monitoring unit 111 monitors the consumption of the battery 112 and notifies the control unit 117 of the monitoring result. When the incoming call transmission means at the time of incoming call is set to vibrator 113a, control unit 117 transmits battery 11 notified by battery voltage monitoring unit 111.
If the voltage of the second (hereinafter simply referred to as battery voltage) is equal to or less than a certain value, the incoming call transmission means is switched from the vibrating call of the vibrator 113a having large power consumption to the ringer 114 having small power consumption.
Switch to ringing call a. As a result, the consumption of the battery 112 can be saved, and the standby time and the talk time can be extended.

The internal clock of the timer management unit 119 is used as a timer for turning off the light. This turning-off timer is an LCD backlight 115 which is a lighting function of the portable wireless communication device.
And a timer for determining whether or not to light the numeric keypad illumination 116. By setting the turn-off time range of the turn-off timer in accordance with the illuminable time zone, the LCD backlight 115 and the numeric keypad illumination 116 can be turned off during the daytime when the bright lighting function is unnecessary. As a result, the consumption of the battery 112 can be saved, and the standby time and the talk time can be extended.

(Communication related control) When communication is continued,
During this time, the battery 112 continues to be gradually consumed. The battery voltage monitoring unit 111 monitors the consumption of the battery 112 and notifies the control unit 117 of the monitoring result. The control unit 117 controls the battery voltage notified by the battery voltage monitoring unit 111 and the wireless unit 118.
The transmission power is determined based on the reception electric field strength measured in (the transmission power is weaker as the remaining capacity of the battery voltage is smaller or the reception electric field strength is stronger, and conversely, the transmission power is larger or the reception electric field strength is weaker. The transmission power is controlled so as to reduce the power consumption. As a result, the consumption of the battery 112 can be saved, and the standby time and the talk time can be extended. Hereinafter, the power control method will be specifically described using a processing routine.

(Power Control Processing Routine During Standby)
FIG. 3 is a diagram illustrating an example of a power control processing routine (hereinafter, abbreviated as a standby processing routine) performed by the portable wireless communication device according to the embodiment of the present invention during standby. Less than,
An example of a standby processing routine of the portable wireless communication device according to one embodiment of the present invention will be described with reference to FIG.

The standby processing routine is started after the power of the portable radio communication device is turned on or after the communication is completed.
First, the battery voltage is measured (step S3).
01). According to the measured battery voltage, according to FIG.
The remaining battery level classification in the current state is determined. Here, the remaining battery level is one variable when determining the transmission power according to FIG. In the description of the present embodiment, the remaining battery level is simply represented by letters L, M, and H for easy understanding, but when the present process is actually performed, any normalized voltage value is used. Etc. may be used as variables.

While waiting for an incoming call, a determination is made as to whether or not an incoming call has occurred. After the above-described measurement of the battery voltage (step S301), the result of the determination is executed. (Step S302). Here, if an incoming call has not occurred, the process proceeds to the determination in step S303, and if an incoming call has occurred, the process proceeds to the determination in step S307.

If an incoming call has occurred, a method of notifying the incoming call is determined (step S307). Here, as a notification method of the incoming call, there are a method of notifying the incoming call through hearing by ringing the ringer 114a, and a method of notifying the incoming call through the bodily sensation caused by the vibration of the vibrator 113a (note that
The method of receiving the vibrator 113a consumes more current than the method of ringing the ringer 114a). Here, if the battery voltage measured in step S301 is equal to or smaller than an arbitrarily predetermined threshold, the ringer 1 is automatically set even if the incoming call of the vibrator 113a is set as the incoming call notification method.
Switch to 14a ringing (step S308). However, if the battery voltage is equal to or higher than the threshold value, the incoming call is notified with the set notification method (step S309). After performing this process, the process moves to step S303.

On the other hand, if an incoming call has not occurred, or after the above-described incoming call notification method has been determined, it is determined whether or not a key has been pressed (step S30).
3). Here, if the key is pressed, it is determined that communication is to be performed, and the process proceeds to step S304.
On the other hand, if the key is not pressed, it is determined that the communication is not performed, and the process shifts to step S301 to repeatedly execute the above-described process of measuring the battery voltage.

If it is determined that the key has been pressed and communication is to be executed, the current time is set to the preset light-off time range of the light-off timer (the light-off time range of the light-off timer is set as described above. (Set in accordance with the illumination time zone) is determined (step S304). Here, if the current time is within the turn-off time range of the turn-off timer, L
A process for turning off (ie, not turning on) the CD backlight 115 and the numeric keypad illumination 116 is performed (step S305). However, if the current time is not within the turn-off time range of the turn-off timer (or if the turn-off timer is not set), the LCD backlight 1
Then, a process of turning on the illumination light 15 and the numeric keypad illumination 116 is performed.

After the above-described processing by the light-off timer, pressing a key is a response operation to an incoming call (a key operation to start a call to receive an incoming call) or an operation to complete the outgoing call process (a dial number for a communication partner). If the operation is a press completion operation), the flow shifts to the communication routine of step S310 to enter the communication state. However, when the operation is not the above operation, the process is repeatedly executed from the above-described process of measuring the battery voltage (step S301).

(Transmission Power Control Processing Routine During Communication) FIG. 4 shows an example of a power control processing routine (hereinafter abbreviated as a communication processing routine) executed by the portable wireless communication apparatus according to an embodiment of the present invention during communication. FIG. Hereinafter, an example of a communication processing routine of the portable wireless communication device according to the embodiment of the present invention will be described with reference to FIG.

The communication processing routine is started when the portable radio communication device shifts to the communication state (step S310). First, it is determined whether or not the communication has been completed (step S401). If the communication has been completed, the process proceeds to step S405. If the communication has not been completed, the process proceeds to step S402.

If it is determined that the communication has not been completed,
The current battery voltage is measured (step S40).
2). Based on the measured battery voltage, the remaining battery level classification in the current state is determined according to FIG. Battery level classification
It is used when determining the transmission power in FIG. For example, when the measured battery voltage is 3.2 V (the remaining battery level is set to “L”) and the received electric field strength measured at that time is 45 dBμV, the transmission power is 4 mW in the PHS. 1.0 PW in PDC
Is determined.

Here, the transmission power in the PHS is 10
mW or less, in FIG.
Other transmission power is determined using mW as the reference transmission power of PHS (in the case of PHS, the transmission power is always fixed at 10 mW at present). For PDCs, the maximum transmission output is defined by the type, and the PDC type 1 defined in the PDC standard (RCR STD-27) developed by the Association of Radio Industries and Businesses (ARIB). The transmission power is specified to be 3 W or less. Therefore, in FIG. 6, another transmission power is determined using 3W as the reference transmission power of the PDC. As the current state of PDC, a process is performed in which the transmission power is controlled according to a transmission power control instruction from a base station.

When the received electric field strength is equal to or higher than 60 dBμV and equal to or lower than 25 dBμV, the transmission power is kept constant regardless of the measured battery voltage. This is because when the received electric field strength is 60 dBμV or more, it can be determined that the base station is in the immediate vicinity, but the transmission power (P
This is because if it is 2 mW or less for HS and 0.5 W or less for PDC, the communication quality may be degraded. Further, when the received electric field strength is 25 dBμV or less, it can be determined that the base station exists only in a distant place, and the communication quality is ensured by transmitting at the reference transmission power (that is, the maximum transmission power).

After the transmission power is determined, the transmission power is controlled (step S404). Then, after this processing is completed, the process returns to step S410, and the above-described routine is repeated until the communication is completed. During the control of the transmission power, the transmission power instruction message instructed from the base station is ignored. This transmission power instruction message is a PDC signal used by the base station to ensure communication quality.
This is a function for controlling the transmission power. Even if this transmission power indication message is ignored, the message itself from the base station is only continuously retransmitted, and the communication itself is not disconnected. Also, it has no effect on battery consumption.

On the other hand, if it is determined in step S401 that the communication has been completed, the control of the transmission power is stopped (step S405). Thereafter, the process returns to the standby processing routine to enter a communication standby state (step S310).

By the above processing, it is possible to reduce the power consumption during communication and during standby, that is, to prevent the built-in battery from being quickly consumed, and to realize the “continuous standby time” and “continuous standby time” which are important specifications of the portable radio communication apparatus. Extension of "communication time" can be realized.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating an example of a usage environment of a portable wireless communication device according to an embodiment of the present invention.

FIG. 2 is a block diagram illustrating an example of a configuration of a portable wireless communication device according to an embodiment of the present invention.

FIG. 3 is a diagram showing an example of a power control processing routine executed when the portable wireless communication device according to the embodiment of the present invention is on standby.

FIG. 4 is a diagram showing an example of a transmission power control processing routine executed at the time of communication of the portable wireless communication device according to one embodiment of the present invention.

FIG. 5 is a diagram illustrating an example of determining a remaining battery level category based on a measured battery voltage.

FIG. 6 is a diagram illustrating an example in which transmission power is determined based on a reception electric field strength and a remaining battery level division.

[Description of Signs] 11: Portable wireless communication device 12: Wireless base station 13: Wireless communication line 14: Wired communication network 111: Battery voltage monitoring unit 112: Battery 113: Vibrator driving unit 114: Ringer driving unit 115: LCD backlight 116: numeric keypad illumination 117: control unit 118: radio unit 119: timer management unit

Claims (7)

[Claims] 1. A portable radio communication device that is movable and wirelessly connected to a base station, and that measures a received electric field intensity from the base station during communication. And a battery voltage measuring means for measuring a battery voltage of the communication device, based on both the received electric field strength and the battery voltage,
A transmission power determining unit that determines transmission power of the communication device, wherein the transmission power determining unit determines the transmission power so as to reduce power consumption during communication. . 2. The transmission power determination unit has a reception electric field strength determination threshold value, and when the reception electric field strength value is equal to or greater than the reception electric field strength determination threshold value, regardless of the battery voltage. The portable wireless communication device according to claim 1, wherein the transmission power is determined to be an arbitrary value of transmission power equal to or less than a reference transmission power. 3. The transmission power determination means has a reception electric field strength determination threshold, and when the reception electric field strength is less than the reception electric field strength determination threshold, regardless of the battery voltage, The portable radio communication device according to claim 1, wherein the transmission power is determined as a reference transmission power. 4. The transmission power determination means comprises: a first reception field strength determination threshold; and a second reception field strength determination threshold lower than the first reception field strength determination threshold. When the received electric field strength is a value equal to or greater than the first received electric field strength determination threshold, regardless of the battery voltage, the transmission power is set to an arbitrary value of transmission power equal to or less than a reference transmission power. Is determined, and if the received electric field strength is less than the first received electric field strength determination threshold value and is a value equal to or more than the second received electric field strength judgment threshold value, Based on both the battery voltage, determine the transmission power from a plurality of power values set in advance, and, if the received electric field strength is a value less than the second received electric field strength determination threshold, Regardless of the battery voltage, the transmission power is set to the reference The transmission power is determined.
A portable wireless communication device according to claim 1. 5. A portable wireless communication device having a clock function, wherein the clock function includes time setting means for setting a light-off control start time and a light-off control end time of a lighting function of the portable wireless communication device. A portable wireless communication device. 6. The time from the light-off control start time to the light-off control end time in the time setting means is set in accordance with a time zone in which it is not necessary to turn on the lighting function. Item 6. The portable wireless communication device according to Item 5. 7. A portable wireless communication device which is movable and wirelessly connected to a base station, wherein a battery voltage measuring means for measuring a battery voltage of the communication device, and the base station From the base station, which communicates that there has been communication from the base station, and has a relatively low power consumption compared to the first incoming call transmission means. Means having a battery voltage threshold for determining the battery voltage, and selection control means for controlling selection of an incoming call transmission means, wherein the selection control means includes a battery voltage threshold for the battery voltage. A portable wireless communication apparatus characterized in that when the value is equal to or less than the value, the first incoming call transmitting means is automatically switched to the second incoming call transmitting means.