JPH01314441A - Moving body communication device - Google Patents

Abstract

PURPOSE:To efficiently execute battery saving by switching the turning-on and off of a power source in an audible tone input and output system and a transmitting and receiving system when it is discriminated that a moving body communication device is in the service area of a base station and further switching the turning-on and off of the power source in the control system when it is discriminated that the device is out of the service area. CONSTITUTION:In a portable radio 100, when a CPU161 receives a synchronization establishing signal to be outputted when the respective synchronization of D, P and A channels in a prescribed control signal, which is outputted from the base station, can be obtained from a control signal processing part 168, a switch 192b is opened by a switch changing-over circuit 193b with a prescribed time interval. In such a case, the power source is always supplied tot he CPU161. When the CPU161 receives a synchronization dislocating signal, which is outputted when the respective synchronization of the D, P and A channels in the prescribed control signal to be outputted from the base station can not be obtained, from the control signal processing part 168, a timer 194 is operated and a switch 192a is opened by a switch changing-over circuit 193a.

Description

[Detailed Description of the Invention] [Object of the Invention] (Before Industrial Use) This invention is applicable to mobile objects such as mobile radio telephone devices, portable radio telephone devices, etc. used in mobile objects such as movable vehicles and people. Related to communication devices.

(Prior Art) Telephone systems have become widespread as a means of transmitting information. In this telephone system, the telephones serving as terminals are operated by DC power supplied from the central office, and multifunctional types using ICs, etc.
Can you get backup power from an AC power supply using an AC adapter? 1? It has become so.

By the way, in recent years, telephone services have become more diverse.
Services are being implemented that give mobility to the telephone. For example, there are wireless telephones that are equipped with telephones in mobile bodies such as transportation vehicles such as automobiles, and portable wireless telephones that can be carried by individuals.

In such wireless telephones, the power required to operate the telephone device is mainly obtained from a rechargeable battery or a battery.

Therefore, it is necessary to suppress the power consumption in the wireless telephone device as much as possible and to save the battery.

(Problems to be Solved by the Invention) As described above, in mobile communication devices such as wireless telephones, it is necessary to perform efficient battery saving.

The present invention is intended to solve the above-mentioned problems, and an object of the present invention is to provide a mobile communication device that can efficiently save battery.

[Configuration of the Invention (Means for Solving the Problems) The present invention provides a mobile communication device that transmits and receives data to and from a base station via a wireless line, based on signals sent from the base station. Discrimination means for determining whether the communication device is within the service area of the base station or not;
A switching means for switching on/off the power of at least a control system, an audible sound input/output system, and a transmitting/receiving system of the mobile communication device, and a determination result by the determination means that the mobile communication device is within the service area of the base station. When it is determined that When it is determined that the mobile communication device is outside the service area of the base station, the switching means is operated at a predetermined time to turn on/off the power of the control system, audible sound input/output system, and transmission/reception system. and a power supply control means for controlling the switching.

(Function) In the present invention, when it is determined that the mobile communication device is within the service area of the base station, the switching means is operated at a predetermined time to turn on/off the power of the audible sound input/output system and the transmission/reception system. When it is determined that the mobile communication device is outside the service area of the base station, the switching means is operated at a predetermined time to turn off the power for the control system, audible input/output system, and transmission/reception system. Since it is controlled to switch on/off, battery saving can be performed efficiently.

(Example) Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram illustrating an embodiment in which the present invention is applied to a portable and vehicle-mounted wireless telephone device.

The wireless telephone device shown in the figure is a portable wireless device 100.1'?
j It is composed of a mounting section main body 200.

The portable radio device 100 includes an antenna 101 and a changeover switch 1.
02. An audio/control unit that performs overall control of the entire device, consisting of a radio unit 103 that forms a wireless line with a base station (not shown) and transfers signals, a control unit 104, and an audio unit 105. 106, an IDROM 107 in which the system ID number of the zone corresponding to the location where this device is registered and a telephone number corresponding to the location where this device is registered, is connected to the power selector switch 108. , electric aj in the portable radio device 100
A power supply control unit 109 that controls the supply, a rechargeable battery 1101 that serves as a power source when portable, a connection unit 111 that is connected to the vehicle-mounted unit main body 200, an operation display unit 112.1, a speaker 113 and a microphone 114 for human output of listening sounds. , an output amplifier 115, and a human power amplifier 116. The operation display section 112 includes a key section 117 on which a predetermined key is pressed manually, a display section 118 on which a predetermined display is performed, a switch section 119 on which various types of switching are performed, a key section 117, a display section 118, and a switch section 119. Control operations/
It is composed of a display control section 120 and a voltage detection circuit 130 that detects the voltage level of a power supply path 131.

The output amplifier 115 amplifies an audible sound signal (voice signal) sent from the audio section 105 of the portable radio device 100 and outputs it from the speaker 113. The input amplifier 116 amplifies the audible signal (speech signal) input from the microphone 114. The amplified signal is manually input to the audio section 105 of the portable radio device 100.

The operation/display control unit 120 is the audio/control unit 106
It performs overall control on the operation display section 112 based on control signals sent from the control section 117, and also sends out control signals manually inputted from the key section 117 to the audio/control section 106. The display unit 118 consists of a liquid crystal display (not shown) and a display driver.
Based on the control of the display control unit 120, the liquid crystal display is driven to perform a predetermined display. The key part 117 is "0" to "9".
” number keys, “*”, “#”, rSNDJ, rsTO
J, ``ENDJ, ``RcLJ, rF
cNJrCL RJ, ``EMRJ, rMU
TEJ, rT.

It consists of a keypad (not shown) such as NEJ function keys, and when the keypad is pressed, this is recognized by the operation/display control section 120. The switch unit 119 is provided with a hook switch and an 0N10FF switch (not shown), and the hook switch allows the portable radio device 100 to be
on-hook or off-hook. Note that the hook switch may also be provided in the 11i cultivation section main body 200.

The 0N10FF switch is the 0N1 switch for this entire wireless telephone device.
0FF is switched, and the switching signal is sent from the operation/display control section 120 to the audio/control section 106.

The in-vehicle main unit 200 includes an antenna 20 attached to the vehicle.
1. A booster 202 that amplifies the signal transmitted and received by the antenna 201 to a constant power, and a booster 202 that amplifies the signal transmitted and received by the antenna 201, and a booster 202 that amplifies the signal transmitted and received by the antenna 201.
Audio/- control section 20 that performs overall control of the entire system.
3. A power supply control unit 204 that supplies power from the vehicle battery B to various parts, a connection unit 205 that is connected to the connection unit 111 of the portable radio 100 via a coaxial cable 300, and a speaker for outputting audible sound 206 and microphone 20
7. The main part is composed of an output amplifier 208 and an input amplifier 209. The booster 202 is an antenna duplexer 2
10.211, receiving amplifier 212, transmitting amplifier 21
3. It consists of an automatic power control circuit (APC) 214 that controls the transmission level of the transmission amplifier 213.

Next, details of the portable radio device 100 will be explained.

FIG. 2 is a block diagram showing in detail the configuration of the above-mentioned portable radio device 100.

As shown in the figure, the radio section 103 includes a demodulator 131, a modulator 132, a power amplifier 133, a duplexer 134,
It is composed of a synthesizer 135. Demodulator 131
is transmitted through the antenna 101, changeover switch 102, and duplexer 134 on the portable radio device 100 side, or through the antenna 201, booster 202, and
Demodulation of the received signal from the base station, which is input manually via the changeover switch 102 and the duplexer 134, is performed. Note that this signal includes a control signal, an audible sound signal, and the like. The modulator 132 modulates the audible signal, control signal, etc. output from the audio/control unit 106 to generate a transmission signal. Power amplifier 133 amplifies the transmission signal output from modulator 132. The duplexer 134 is
A received signal input via the antenna 101 or 201 is sent to the demodulator 131, and a transmitted signal input via the modulator 132 and power amplifier 133 is sent to the antenna 101 or 201.

The synthesizer 135 is a local oscillator for channel selection, and the frequency to be demodulated by the demodulator 131 and the frequency to be demodulated by the modulator 13
2 specifies the frequency to be modulated.

The audio/control unit 106 includes a CPU 161, an oscillator/
Frequency divider 162, address decoder 163, ROM 164
, RAM 165, radio section control section 166, audio section 1
67, control signal processing section 168, audio section control section 16
9, a digital interface 170, and an interrupt controller 171. In the figure, 107 is the above-mentioned IDROM, 109 is a power supply control unit, 172 is, for example, an 8-bit data bus, 173 is an address bus, and 1
74 is a control bus.

The CPU 161 performs overall control of the entire audio/control section 106, and the oscillator/frequency divider 162 controls the entire audio/control section 106.
61, and also divides the frequency of this clock and supplies it as a timing signal to each part. Address decoder 163 outputs predetermined operation signals to each section in response to command signals from CPU 161. ROM164 is
It stores various programs necessary for the operation of the CPU 161.

The RAM 165 stores various data during processing by the CPU 161. The wireless unit control unit 166
The wireless unit 103 is controlled based on the command No. 1. For example, the radio unit control unit 166 instructs the frequency that the synthesizer 135 should specify, the amplification factor that the power amplifier 133 should amplify, the degree of modulation that the modulator 132 should modulate, etc., and outputs from the synthesizer 135 as a measure to prevent malfunction. The out-of-synchronization signal, the output detection signal output from the power amplifier 133, and the like are manually generated and transmitted to the CPU 161. The audio section 167 sends a control signal of the received signal demodulated by the demodulator 131 to the control signal processing section 168, and also sends an audible sound signal of the received signal to the output amplifier 11.
5 to the speaker 113. The audio unit 167 also sends the control signal output from the control signal processing unit 168 and the audible sound signal output from the microphone 114 via the human amplifier 116 to the modulator 132.

Note that the audio section 167 has functions of waveform shaping of the control signal to be sent to the control signal processing section 168 and filtering of the control signal to be sent to the modulator 132.

The control signal processing unit 168 performs bit synchronization and frame synchronization with the control signal output from the audio unit 167, captures control data from the base station included in the control signal, which is a serial signal, as a parallel signal, and Control data as a parallel signal to be sent to the base station is sent to the audio section 167 as a control signal that is a serial signal. Here, in the above-mentioned control signal processing section 168, when obtaining a predetermined synchronization with the manually inputted IIJ control signal, first, synchronization is obtained for the D channel from the predetermined manually inputted control signal. This D channel contains system information and a small signal for specifying the P channel band. When the D channel is synchronized, the P channel is synchronized. teeth,
It contains system information, a call signal, and a signal for specifying the band of the A channel, and when synchronization on the P channel is achieved, the standby state is enabled. Next, synchronize the A channel. This person channel includes system information and a communication channel designation signal.

The audio section control section 169 performs various controls on the audio section 167. For example, the audio section control section 16 performs switching control and control (from the No. 7 processing section 168 or the human power amplifier 116) to send the received signal from the audio section 167 to the control signal processing section 168 or the output amplifier 115. Switching control is performed to input one of the output transmission signals into the audio section 167.

Digital interface 170 provides an interface between audio/control section 106 and operation display section 112 . The interrupt controller 171 interrupts the CPU 161 in response to interrupt commands from various parts.

Next, the configuration of the power supply control section 109 will be explained in detail using FIG. 3.

As shown in the figure, the power supply control section 109 is connected to the vehicle-mounted section main body 2.
It is connected to the power supply control section 204 on the 00 side via the connection section 205.111, and is also connected to the switching terminal of the power supply changeover switch 108 connected to the rechargeable battery 110 side. Further, the power supply control section 109 is connected to the CPU 161 via a power supply line 191a, and the audio section control section 169 and the control signal processing section 168 are connected via a power supply line 191b.
, are connected to the wireless unit control unit 166.

A switch 192a is provided on the power supply line 191a of the power supply control unit 109, and a switch 192b is provided on the power supply line 191b. Switches 192a, 19
2b is set to 0 by the switch changeover circuits 193a and 193b.
N10FF(7) switching is performed. A timer 194 is connected to the switch switching circuit 193a.
This allows the switching operation of the switch switching circuit 193a to be performed. Also, a switch switching circuit 193a.

The CPU 161 is connected to the timer 193b and the timer 194 via a control line 195. and CPU16
1, when the control signal processing unit 168 receives from the control signal processing unit 168 a predetermined control signal output from the base station or a synchronization establishment signal that is output when each of the PSA channels is synchronized, The switch 192b is switched on by the switch switching circuit 193b at predetermined time intervals.
The radio section control section 166 and the control signal processing section 16 are opened.
8 and the audio section control section 169 are turned off at predetermined time intervals to enter an intermittent reception state. Note that in this case, since power is always supplied to the CPU 161, a predetermined time interval is measured by the clock of the CPU 161. The CPU 161 also controls the control signal processing section 16.
8, the control signal processing unit 16 processes an out-of-synchronization signal that is output when each of the D1PSA channels cannot be synchronized in a predetermined control signal output from the base station.
When received from 8, it activates the timer 194 and
The switch 192a is opened by the switch changeover circuit 193a. The above-mentioned out-of-synchronization signal is output when the radio telephone device leaves a predetermined service area and a predetermined synchronization cannot be achieved in a predetermined control signal from a base station or in a PSA channel. Then, by opening the switch 192a described above, the CPU 1
61, the power of the wireless section control section 166, the control signal processing section 168, and the audio section control section 169 is turned off, and a battery saving state is entered. Note that at this time, RAM1
A timer mode flag indicating timer operation indicating this state is set at 65, and power supply voltage is supplied to RAM 165 by a backup battery (not shown). Also, when the timer 194 times out, this signal is output to the switch changeover circuit 193a and the switch 192
a is in a closed state, power is supplied to the CPU 161, and then the switch changeover circuit 193b is operated by the CPU 161, the switch 192b is brought into a closed state, and power is supplied to each part.

Further, the voltage detection circuit 130 detects the voltage level of the power supply path 131, and if the voltage of the power supply path 131 is equal to or higher than a predetermined voltage, the voltage detection circuit 130 switches the power supply changeover switch 108 between the power supply path 131 and the 10 power supply control units. At the same time, the selector switch 102 is driven so that the wireless section 103 and the booster 202 are connected. Power supply path 13
If the voltage of 1 is less than the predetermined voltage, the power selector switch 1
08 so that the battery 110 and the power supply control section 109 are connected, and the selector switch 102 is driven to connect the battery 110 and the power supply control section 109.
3 and the antenna 101 are connected to each other. Therefore, when the portable radio device 100 is not connected to the IItJ & section main body 200, the power control section 109 is supplied with power from the rechargeable battery 110, and the radio section 103 is connected to the antenna 10.
Connected to 1.

Next, the power supply control operation of the radio telephone device configured as described above will be explained using the state transition diagram shown in FIG.

As shown in the figure, first, when the power of the portable radio device 100 is turned on (including when the power is turned on after the timer 194 has timed up) (ST1), the CPU 161
accesses the RAM 165 and confirms the timer mode (ST2). When it is confirmed that it is not in timer mode,
A hard check of each part is performed (ST3). Next, initialization is performed. At this time, in ST2, initialization is also performed when the power is turned ON due to time-up from the timer mode (ST4). In this initialization, the control signal processing unit 168 synchronizes the system information of the D channel having the strongest received field strength (R3SIilN fixed) among the plurality of D channel signals in a predetermined control signal.

The D channel includes a signal specifying the P channel band. When the D channel is synchronized and initialized, the P channel is synchronized (S T 5). This P-channel synchronization is achieved by synchronizing multiple P-channels in a given control signal.
Among the channel signals, the received field strength is the strongest (R5S
(Measurement) P channel synchronization is achieved in the control signal processing section 168. The P channel includes system information, an incoming call signal, and a signal specifying the band of the A channel. After this, the A channel is synchronized (ST6).

This synchronization of the A channel is determined by the reception field strength being the strongest (R
3SI4K1 constant) A channel synchronization is controlled by control signal processing unit 1
Taken at 68. The A channel contains system information and a communication channel designation signal.

In this state, the standby mode is set, and the call and 6 calls are possible. After this, if synchronization cannot be achieved in ST6, a synchronization establishment signal is output from the control signal processing unit 168 to the CPU 161, and the CPU 161 then switches the switch 1 by the switch changeover circuit 193b at a predetermined time.
92b is opened and closed.

As a result, the wireless section control section 166 and the control signal processing section 168
, the power to the audio section control section 169 is turned on and off at predetermined time intervals under the control of the CPU 161, and an intermittent reception state is established (ST7). In this case, it is assumed that the power-on state continues for a sufficient period of time to detect a predetermined synchronization signal and to detect the presence or absence of incoming and outgoing calls.

In addition, if synchronization cannot be achieved in ST4.5.6 (out of synchronization), the control signal processing section 168 sends the CPU 16
An out-of-synchronization signal is output to the CPU 161.
activates the timer 194, and further switches the switch changeover circuit 1.
93a opens the switch 192a. As a result, the CPU 161, the wireless section control section 166, the control signal processing section 1
68, the power to the audio unit control unit 169 is cut off (
S78). After this, when the timer 194 times out, the process returns to ST1.

Next, the operation of synchronization detection in each channel will be explained.

FIG. 5 is a flowchart for explaining the operation of D channel synchronization detection.

As shown in the figure, first, the received electric field strength of a plurality of D channels is measured (RS S I all determination) from a predetermined control signal input in the control signal processing unit 168 (
STII). Then, the D channel with the strongest electric field strength is selected (ST12). Thereafter, the selected D channel is synchronized and establishment of synchronization is detected (ST13). In this 5T13, if synchronization is not established (out of synchronization), for example, a counter in the CPU 161 is counted up (ST14). Next, it is confirmed whether the counter value of the counter is 5 or more (ST15).

At 5T15, if the counter value is less than 5, the process returns to 5T13 and detection of synchronization establishment is performed. Also, S
In TI 5, if the counter value is 5 or more, an out-of-synchronization signal is sent from the control signal processing unit 168 to the CPU 16.
1, and this causes the CPU 161 to control the power supply control unit 1.
09 is activated, the switch switching circuit 193a is activated to open the switch 192a, and the power to the CPU 161, the wireless section control section 166, the control signal processing section 168, and the audio section control section 169 is turned off.

Further, in 5T13, if synchronization is established, the operation moves to P channel selection using a signal specifying the P channel band obtained from the D channel.

Next, the synchronization detection operation in the P channel will be explained.

FIG. 6 is a flowchart for explaining the operation of P channel synchronization detection.

As shown in the figure, first, the received electric field strength of a plurality of P channels is measured (R3SIal determination) from a predetermined control signal input manually in the control signal processing unit 168 (ST21
). Then, the LAP channel with the strongest electric field strength is selected (ST22). Thereafter, the selected P channel is synchronized and establishment of synchronization is detected (ST23). This 5T2
In step 3, if synchronization is not established (out of synchronization), for example, a counter in the CPU 161 is counted up (ST24). Next, it is confirmed whether the counter value of the counter is 5 or more (ST25).

At 5T25, if the counter value is less than 5, the process returns to 5T23 and detection of synchronization establishment is performed. Also, 5
At T25, if the counter value is 5 or more, an out-of-synchronization signal is sent from the control signal processing unit 168 to the CPU 16.
1, and this causes the CPU 161 to control the power supply control unit 1.
At the same time, the timer 194 of 09 is activated, the switch switching circuit 193a is activated to open the switch 192a, and the power of the CPU 161, the wireless section control section 166, the control signal processing section 168, and the audio section control section 16 is cut off.

Further, in 5T23, when synchronization is established, a signal specifying the band of the A channel obtained by the P channel is used to shift to a standby operation, which is an operation for selecting the A channel.

Next, the operation of synchronization detection in the A channel will be explained.

FIG. 7 is a flowchart for explaining the operation of A channel synchronization detection.

As shown in the figure, first, the received electric field strength of a plurality of A channels is measured (RS S l 7m fixed) from a predetermined control signal input manually in the control signal processing unit 168 (S
T31). Then, the A channel with the strongest electric field strength is selected (ST32). Thereafter, the selected A channel is synchronized and establishment of synchronization is detected (ST33). This 5
If synchronization is not established at T33 (out of synchronization), for example, a counter in the CPU 161 is counted up (ST34). Next, it is confirmed whether the counter value of the counter is 5 or more (ST35).

At 5T35, if the counter value is less than 5, the process returns to 5T33 and detection of synchronization establishment is performed. Also, 5
At T35, if the counter value is 5 or more,
An out-of-synchronization signal is sent from the control signal processing unit 168 to the CPU 161.
This causes the CPU 161 to control the power supply control unit 10.
9 operates the timer 194, and operates the switch changeover circuit 193a to open the switch 192a,
CPU 161, wireless unit control unit 166, control signal processing unit 1
68. Power off the audio section control section 169. In addition, in 5T33, if synchronization is established, the standby mode is set, and it is confirmed whether outgoing calls and incoming calls are received (S
T36) If there is an incoming/outgoing call, the mode is set to incoming/outgoing call mode.

Also, if there are no incoming or outgoing calls, the mode becomes intermittent reception mode (ST3
7). In this intermittent reception mode, after the standby state is entered at 5T36, a synchronization establishment signal is output from the control signal processing unit 168 to the CPU 161, and as a result, the CPU 16
1 operates the switch changeover circuit 193b at a predetermined time to open and close the switch 192b, and turn on/off the power of the radio section control section 166, the control signal processing section 168, and the audio section control section 169. When in the intermittent reception mode, the process returns to 5733 and establishment of synchronization is detected.

Therefore, in this embodiment, when this wireless telephone device is within the service area, the CPU 161, which is the control system, turns off the power to the transmitting/receiving system and the audible input/output system at a predetermined time so as to enter the intermittent reception state. Furthermore, when this wireless telephone device moves out of the service area, as described above, the establishment of synchronization of a predetermined channel in the control signal is detected, and if synchronization is not established, the wireless telephone device is determined to be out of the service area. Since the control system, transmitting/receiving system, and audible sound input/output system are powered off, unnecessary battery consumption can be prevented, which makes it possible to carry and use the portable radio 100 of this radio telephone device. In this case, battery (rechargeable battery) saving can be performed particularly efficiently. In other words, since the rechargeable battery that serves as a power source when using the portable radio 100 has a limited usage time, by efficiently performing the battery saving described above, the usage time is extended compared to conventional ones. can be done.

In the above-described embodiment, whether or not this wireless telephone device is within the service area of the base station is determined by the base station when synchronization with a predetermined control signal in a signal from another station has not been established five times or more. It was determined that it was outside the station's service area, but
When synchronization with a predetermined control signal is not established once or multiple times, it may be determined that the base station is outside the service area, and a predetermined power supply ON/OFF switching control may be performed.

Furthermore, in each of the embodiments described above, whether or not this wireless telephone device is in the service area of the base station is determined by the base station's service when synchronization with a predetermined control signal in the signal from the base station is not established. It is determined that the base station is outside the service area, but when the received field strength of the control signal is measured and the measured field strength value is smaller than a predetermined threshold, it is determined that the base station is outside the service area and the power is turned on/off. Alternatively, switching control may be performed.

Furthermore, in this embodiment, the portable radio device 100 performs the battery saving operation regardless of whether the portable radio device 100 is connected to the vehicle-mounted unit main body 200.
Since the battery capacity of the in-vehicle battery B connected to the in-vehicle section main body 200 is relatively large, when the portable radio device 100 is connected to the in-vehicle section main body 200, the portable radio device 100 is configured not to perform battery saving operation. Good too. In this case, a power supply changeover switch 108 is provided between the ten power supply control units and the audio/control unit 106.

Furthermore, by using the same configuration as the power supply control section 109 of the vehicle-mounted section main body 200 and supplying power to the audio/control section 203 etc. based on the control signal from the CPU 161, the portable radio device 100 can also be controlled inside and outside the zone. You can save battery in .

[Effects of the Invention] As explained above, in the mobile communication device of the present invention, the switching means can be operated at predetermined time intervals when it is determined that the mobile communication device is within the service area of the base station. Controls the power of the listening input/output system and the transmitting/receiving system to be switched on/off, and operates the switching means at predetermined time intervals when it is determined that the mobile communication device is outside the service area of the base station. Since the system, audible input/output system, and transmitting/receiving system are controlled to be switched on/off, battery saving can be performed efficiently.

[Brief explanation of the drawing]

FIG. 1 is a block diagram illustrating an embodiment in which the mobile communication device of the present invention is applied to a portable and vehicle-mounted type radio telephone device, and FIG. 2 illustrates details of the portable radio device shown in FIG. 1. 3 is a block diagram for explaining the details of the power supply control section in FIG. 2, and FIG.
FIG. 5, FIG. 6, and FIG. 7 are state transition diagrams for explaining the power control operation in the radio telephone device shown in the figure, and flowcharts for explaining the synchronization establishment detection operation of each channel in FIG. . 100... Portable radio device, 101.201... Antenna, 103... Radio unit, 106... Audio/control unit, 109... Power supply control unit, 161... CPU,
166... Radio unit control unit, 168... Control signal processing unit, 169-... Audio unit control unit, 192a119
2b...Switch, 193a, 193b...Switch switching circuit, 194...Timer. Applicant Toshiba Corporation Patent Attorney Sasa Suyama - Figure 2 Figure 4 Figure 5 Figure 6

Claims (3)

[Claims] (1) In a mobile communication device that transmits and receives data to and from a base station via a wireless link, whether or not this mobile communication device is within the service area of the base station based on a signal sent from the base station a switching means for switching on/off the power of at least a control system, an audible sound input/output system, and a transmitting/receiving system of the mobile communication device; When it is determined that the device is within the service area of the base station, the switching means is operated at predetermined time intervals to switch on/off the power of the audible sound input/output system and the transmission/reception system; , when the determination result by the determination means is that the mobile communication device is outside the service area of the base station, the switching means is operated for a predetermined time to control the control system, the audible sound input/output system, and A mobile communication device comprising: a power supply control means for controlling switching on/off of power of a transmitting/receiving system. (2) The determining means measures the received field strength of the signal and determines that the mobile communication device is outside the service area when the measured field strength value is smaller than a predetermined threshold. Mobile communication device. 3. The mobile communication device according to claim 1, wherein the determining means determines that the mobile communication device is outside the service area when a predetermined synchronization signal cannot be detected.