JP2003218769A - Radio communication apparatus, method for controlling radio communication apparatus, program for controlling radio control apparatus, and storage medium - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a radio communication apparatus capable of effectively utilizing a memory and reducing communication expenses while maintaining low power consumption. <P>SOLUTION: A CPU 508 detects the reception power of arriving reference signals, detects the residual capacity of a memory for storing information to be transmitted, and performs control so as to change at least either a communication speed or an exchange system on the basis of the detected reception power and the residual capacity of the memory. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wireless communication device, a method for controlling the wireless communication device, a control program for the wireless control device, and a storage medium storing the control program.

[0002]

2. Description of the Related Art DS-CDMA (Direct Sequence-Code Division Multiple Access) has been attracting attention as a promising candidate for a radio access method for next-generation mobile communication.

This DS-CDMA is a system in which a plurality of users use the same frequency band for communication, and the users are identified by a spread code.

In DS-CDMA, in order to reduce interference between users as much as possible, each transmission is performed so that the reception power at each receiving end of a base station and a mobile station becomes a minimum necessary to maintain a desired QoS. Power is controlled.

Further, in DS-CDMA, not only the identification between users by a spread code but also code multiplexing using mutually orthogonal codes called layered orthogonal codes ensures a variation in communication speed. There is.

[0006] In DS-CDMA, the minimum receiving end power or receiving SIR (Signal to Inteer) required to realize a desired QoS depends on the communication speed.
rference Ratio: desired wave to interference signal power ratio) is present.

In order to maintain the minimum required receiving power or receiving SIR at each receiving end, when the mobile station receives the reference signal from the base station, the magnitude of the receiving power or receiving SIR is set to the base station. Since the distance variation (section median) is determined by the distance between the mobile station and the mobile station, open loop transmission power control is performed to compensate for this section median.
The transmission power on the mobile station side is determined.

Further, after the signal is started to be transmitted, high-speed closed loop transmission power control is executed between the base station and the mobile station in order to follow the instantaneous value fluctuation, and the base station of the signal from the mobile station is transmitted. Power or reception S at the receiving end of the
In order to maintain IR, a transmission power control signal is transmitted from the base station to the mobile station, and the transmission power of the mobile station is changed based on this transmission power control signal.

As a conventional example of such a battery-powered wireless communication device equipped with a wireless access system, Japanese Patent Application Laid-Open No. 2-212058
No. 000-69107 (hereinafter referred to as the first conventional example) exists.

Hereinafter, the first conventional example will be described with reference to FIGS.
Will be explained.

FIG. 5 is a block diagram showing a schematic configuration of a wireless communication device (MS: Mobile Station) which is a first conventional example, and FIG. 6 is a diagram showing a power saving effect of the wireless communication device which is a first conventional example. In the figure, the vertical axis represents battery capacity and the horizontal axis represents communication time.

The MS shown in FIG. 5 is a W-CDMA (W
side Band Code Division Mu
It is a wireless communication device that performs wireless communication according to the multiple access method, and has a function of transmitting and receiving voice, still images, and moving images.

In FIG. 5, reference numeral 501 is a battery for supplying electric power, and 502 is a voltage detection circuit for detecting the voltage of the battery 501. 503 is a CPU (Central Processing Unit), and 504 is three types of wireless communication speeds (2 Mbit).
/ S, 384 Kbit / S, 144 Kbit / S), a wireless unit capable of realizing signals, 505 is an antenna for transmitting and receiving signals, 506 is a speaker for outputting voice information, 5
Reference numeral 07 is a microphone for inputting voice information, 508 is a voice codec, 509 is a data line, and the wireless unit 5
04 and the CPU 503 are lines for transmitting and receiving data. A first control line 510 is a line for transmitting a control signal for controlling the transmission (communication) speed of wireless communication from the CPU 503 to the wireless unit 504.

Reference numeral 511 denotes a first signal line, which is a battery 501.
Is a line that becomes active when the output voltage of the output voltage of the output signal matches the first set voltage value. A second signal line 512 is a line that becomes active when the output voltage of the battery 501 matches the second set voltage value. Reference numeral 513 denotes a third signal line which is used by the CPU 5 to receive data received by the wireless unit 504.
A line for separating the image data and the audio data by 03 and transmitting the audio data to the audio codec 508. A RAM (random access memory) 514 is a memory that temporarily stores data during transmission / reception with the wireless unit 504. 515 is a ROM (Read Only Memory)
Then, it is a memory that stores various programs such as voltage values and control programs related to the first and second settings. A second control line 516 includes a RAM 514 and a ROM.
A line for transmitting / receiving a control signal for reading / writing 515. A display 517 displays the image data received by the wireless unit 504. + BV is the output voltage of the battery 501 (that is, the operating voltage inside the device), 518 is a fourth signal line, and is a line for transmitting image data to the display 517. 51
A fifth signal line 9 is a line for inputting the audio signal digitized by the audio codec 508 to the CPU 503. 520 is a camera for capturing an image, 5
Reference numeral 21 denotes a sixth signal line, which is an image signal from the camera 520 to C
It is a line for inputting to the PU 503. Reference numeral 522 is a keyboard for operating operations such as transmission.

The operation when communication is performed using the wireless communication device of the first conventional example having the above-mentioned configuration will be described.

At the beginning of wireless communication, the battery 501 is in a fully charged state and its output voltage + BV is the rated output voltage. Therefore, the communication (transmission) speed of wireless communication is set to the first communication speed (2 Mbit / S). (Corresponding to) (A in FIG. 6)
See point). At the first communication speed equivalent to 2 Mbit / S, the moving image is reproduced as a smooth video without any discomfort.

When the power of the battery 501 is consumed during the wireless communication and the output voltage decreases, the communication speed is controlled as follows. That is, the output voltage + BV is monitored by the voltage detection circuit 502. The first voltage value when the remaining capacity of the battery 501 reaches 30% and the second voltage value when the remaining capacity reaches 10% are stored in advance in the ROM 5
It is stored in 15. Then, during wireless communication, the power of the battery 501 is consumed and the output voltage + BV becomes the first
If the voltage value of the voltage detection circuit 502 matches the voltage value of
The signal line 511 is activated. CPU 503
Since the first signal line 511 is activated,
Recognize that the remaining capacity of the battery 501 has reached 30%. Then, the CPU 503 switches the wireless communication speed of the wireless unit 504 to the second communication speed (equivalent to 384 Kbit / S) by transmitting a control signal to the wireless unit 504 using the first control line 510 (FIG. 6). B
See point).

As described above, by lowering the communication speed of the wireless communication, the power consumption of the battery 501 becomes gentle, and the communicable time of the wireless communication is longer than that when the wireless communication is continued at the first communication speed. Can be extended.

The output voltage of the battery 501 further decreases,
When the voltage detection circuit 502 detects the second voltage value corresponding to the case where the remaining capacity is 10%, the voltage detection circuit 502 activates the second signal line 512. CPU 503
Recognizes that the remaining capacity of the battery 501 has become 10% due to the activation of the second signal line 512. Then, the CPU 503 uses the first control line 510.
To transmit a control signal to the wireless unit 504, the wireless communication speed of the wireless unit 504 is switched to the third communication speed (144 Kbit / S equivalent) (see FIG. 6).
See point C).

As described above, by lowering the communication speed of the wireless communication from the second communication speed, the power consumption becomes slower than when the wireless communication is continued at the second communication speed. It is possible to further extend the communicable time of.

As described above, the remaining capacity of the battery 501 is indirectly monitored by detecting the output voltage of the battery 501, and the wireless unit 504 is based on the remaining capacity.
When the communication speed of is decreased to the first, second, and third communication speeds in sequence, the available communication time is point E in FIG. 6, whereas communication is performed at the first communication speed as it is. The communicable time when it continues is point D in FIG. That is, the battery 5
If the communication speed is gradually reduced to the first, second, and third communication speeds based on the remaining capacity of 01, the battery 50
Since the power consumption of No. 1 is reduced, the communicable time can be significantly extended as compared with the case where the communication is continued at the first communication speed.

As another conventional example different from the first conventional example, there is JP-A-2000-106605 (hereinafter referred to as the second conventional example). In the second conventional example, not only the communication speed is changed based on the remaining capacity of the battery, but also the illumination brightness of the display device mounted on the wireless communication device is changed, thereby reducing the life of the battery. We are trying to extend it further.

[0023]

However, both the above-mentioned first conventional example and the second conventional example are methods for saving power based on the remaining capacity of the battery, and until the remaining capacity of the battery reaches a predetermined value. Since we are not saving electricity at all,
The actual power saving effect was quite limited.

The present invention has been made to solve the above-mentioned problems of the prior art, and an object thereof is to effectively use the memory and reduce the communication cost while reducing the power consumption. To provide a wireless communication device, a method for controlling the wireless communication device, a control program for the wireless control device, and a storage medium that enable the above.

[0025]

In order to achieve the above object, the wireless communication apparatus of the present invention has a reception power detecting means for detecting the reception power of an incoming reference signal and a memory for storing information to be transmitted. Remaining amount detecting means for detecting the remaining amount of the memory, and at least one of a communication speed and an exchange method based on the received power detected by the received power detecting means and the remaining memory amount detected by the memory remaining amount detecting means. And changing means for changing.

Further, in order to achieve the above object, the wireless communication apparatus of the present invention has an SIR (= S of an incoming reference signal).
ignal to Interference Ratio: SIR detecting means for detecting a desired wave to interference signal power ratio), a memory remaining amount detecting means for detecting a remaining amount of a memory for storing information to be transmitted, and an SIR detecting means for detecting the remaining amount. And a change means for changing at least one of the communication speed and the exchange method based on the SIR and the memory remaining amount detected by the memory remaining amount detecting means.

Further, in order to achieve the above object, a control method for a wireless communication device according to the present invention is a control method for controlling a wireless communication device, the received power for detecting the received power of an incoming reference signal. A detecting step, a remaining memory amount detecting step of detecting a remaining amount of memory for storing information to be transmitted, a reception power detected by the receiving power detecting step, and a memory remaining amount detected by the remaining memory amount detecting step. And a changing step of changing at least one of a communication speed and an exchange method based on the quantity.

In order to achieve the above object, the control method for a wireless communication device of the present invention is a control method for controlling a wireless communication device, wherein the SIR of an incoming reference signal is used.
(= Signal to Interference Ratio: desired signal to interference signal power ratio) SIR detection step, memory remaining amount detection step for detecting the remaining amount of memory for storing information to be transmitted, and the SIR detection step The method further comprises a changing step of changing at least one of the communication speed and the exchange method based on the detected SIR and the remaining memory amount detected by the remaining memory amount detecting step.

In order to achieve the above object, a control program for a wireless communication device according to the present invention is a computer-readable control program for controlling the wireless communication device, wherein the received power of an incoming reference signal is A received power detection step for detecting, and a memory remaining amount detecting step for detecting a remaining amount of the memory that stores information to be transmitted,
A method for causing a computer to execute a changing step of changing at least one of a communication speed and an exchange method based on the received power detected by the received power detecting step and the remaining memory amount detected by the remaining memory amount detecting step. It is characterized by comprising program code.

In order to achieve the above object, the control program of the wireless communication device of the present invention is a computer-readable control program for controlling the wireless communication device, and the SIR (=) of the incoming reference signal. Signal to
Interference Ratio: SIR detection step for detecting desired wave-to-interference signal power ratio), memory remaining amount detection step for detecting remaining amount of memory for storing information to be transmitted, and SIR detected by the SIR detection step.
And a changing step of changing at least one of the communication speed and the exchange method based on the remaining memory amount detected by the remaining memory amount detecting step, the program code causing the computer to execute.

Further, in order to achieve the above object, the storage medium of the present invention is characterized by storing a control program for the wireless communication device.

[0032]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described below with reference to FIGS.

FIG. 1 is a block diagram showing the configuration of a battery-driven wireless communication device according to this embodiment.

In FIG. 1, the same parts as those in FIG. 5 in the above-mentioned first conventional example are designated by the same reference numerals.

1 is different from that of FIG. 5 in that the control lines 101, 105, 106, 701 and the signal line 1 are different.
No. 02, 702, ROM 103, RAM 104, and the description of other components is omitted.

The control line 101 is a line for transmitting a control signal from the CPU 503 to the wireless unit 504 for selecting the exchange method of the wireless unit 504.
The signal line 102 is for notifying the CPU 503 whether or not the wireless unit 504 has switched to the requested exchange method when the exchange method is requested to be selected by the control signal transmitted from the CPU 503 via the control line 101. It is a line for transmitting the signal of.

The CPU 503 stores the data to be transmitted in the RAM.
After being stored in 104 and converted into a data format compatible with the selected exchange method, data is transmitted / received to / from the wireless unit 504 via the data line 509. RA
The wireless unit 50 is connected to the M104 via the CPU 503.
In addition to the data transmitted and received with respect to 4 and the received power of the reference signal or SIR, the remaining amount information of the memory obtained as a result of the memory management is stored. The ROM 103 stores various programs such as a desired received power value or SIR value of the reference signal, a memory remaining amount threshold ThM, and a control program corresponding to the flowcharts of FIGS. The control line 105 is a line for temporarily storing the received data from the CPU 503 in the RAM 103. Control line 1
Reference numeral 06 is a line for temporarily storing data from the ROM 103 in the RAM 104.

The control line 701 transmits to the wireless unit 504 from the CPU 503 the received power of the reference signal arriving at the wireless unit 504 or SIR (Signal to signal).
Interference Ratio: Desired wave-to-interference signal power ratio) is a line for transmitting a control signal for controlling the CPU 503 to transmit. Signal line 70
Reference numeral 2 denotes the received power of the reference signal from the CPU 503 via the control line 701 or SIR (Signal to Int).
interference Ratio: power ratio of desired wave to interference signal) When the request signal is received, the receiving end power or S
It is a line for transmitting IR from the wireless unit 504 to the CPU 503.

The function of the wireless unit 504 will be briefly described below.

The radio unit 504 receives a reference signal, which is constantly transmitted from the base station, from the CPU 503, and when a request signal of the received power or SIR of the SIR is asserted via the control line 701, the radio unit 504 receives the signal via the signal line 702. The received power or SIR is output to the CPU 503. Here, the reference signal is code division multiplexed with user or control information or embedded as a pilot symbol in time multiplexed with a user signal or control signal, and is a scale for measuring the reception state of a signal from a base station. Can be used as In this embodiment,
It is assumed that the received power of the reference signal or SIR (Signal to Interference Ratio) is used for power saving. Further, the wireless unit 504 is connected to the wireless unit 504 through the control line 101.
When the circuit switching method or the packet switching method is selected, it has a function capable of supporting both.

Next, a network in which the radio communication apparatus according to this embodiment is arranged will be described with reference to FIG.

In FIG. 2, reference numeral 201 denotes the wireless communication device shown in FIG. 1, and in FIG. 2, MS (Mobile) is used.
Station). 202 is the base unit BTS
(Base Transceiver System)
Then, wireless communication is performed with the MS 201. Reference numeral 203 denotes a main device MCC (Mobile Communicati)
on Control Center), BTS20
It controls 2 etc. Reference numeral 204 denotes a network such as a public network and a LAN (Local Area network) network, which are connected to the MCC 203 and the MCC 205 on the other side, which will be described later. Reference numeral 205 denotes an MCC (Mobile Communicator) of the other party who communicates.
ation Control Center), 206
Is a BTS (Base Transc)
The user system MS (Mobile Station) 207 communicates with the other party. 20
8 and 209 are other BTSs (Base Transce
(iver System).

The dotted line frame in FIG. 1 shows the communication carrier equipment.

Under the system configuration of FIG. 2, for example, MS
When communicating from 201 to MS207, first, MS2
01 is the BT that is transmitting the reference signal that is received best from the reference signals transmitted from each BTS.
Access to S. If, here, BTS20
It is assumed that the reference signal transmitted from No. 2 is received best.

The MS 201 is connected to the BTS 20 by wireless communication.
Access 2. Then, the BTS 202 which has received the access signal uses the original network of the communication carrier to
Via the CC 203, the calling number of the MS 207 is called to the MCC 205 with which the communication partner MS 207 can communicate. MCC20 that received the calling number
5 calls the MS 207 of the communication partner by wireless communication from the BTS 206 via the unique network to establish communication.

In the system which operates as described above, the MS when the MS 201 and the MS 207 communicate with each other.
The operation state of 201 is as follows.

That is, the user of the MS 201 uses the keyboard 5
22. Press the call button on 22 and enter the calling number of the MS 207 of the communication partner. Upon receiving the calling number, the CPU 503 sets the data line 5 in order to establish communication.
09, the wireless unit 504, and the antenna 505 to transmit the call number. And MS20 of the communication partner
When communication is established by calling 7
Mutual communication is possible with 207.

Here, assume that a still image and a voice message taken by a digital camera are transmitted and received to and from a partner terminal as an application.

Audio data from the MS 201 side includes a microphone 507, an audio codec 508, and a signal line 519.
Is input to the CPU 503 via. On the other hand, the image data is formed by the camera 520 and input to the CPU 503. The CPU 503 temporarily stores the input voice data and image data in the RAM via the address control line 105.
Accumulate in 104. Then, the CPU 503 multiplexes the audio data and the image data and transfers the multiplexed data to the wireless unit 504 via the data line 509. Wireless unit 504
Wirelessly transmits the multiplexed audio data and image data from the antenna 505 to the BTS 202.

Further, the received data from the MS 207 of the communication partner is input to the CPU 503 via the antenna 505, the radio unit 504 and the data line 509. CPU5
03 temporarily stores the received data in the RAM 104 via the address control line 105. Then, the CPU 503
The received data is separated into audio data and image data, and the audio data is output from the speaker 506 via the signal line 513 and the audio codec 508. Further, the image data is transferred to the display 517 via the signal line 518 for display.

Next, the transmission rate control operation and the exchange method control operation for saving the battery 501 in the wireless communication apparatus according to this embodiment will be described with reference to FIGS. 3 and 4.

Broadly speaking, the wireless communication terminal (mobile station M
S) is located away from the base station (BTS), the reception power of the reference signal in the wireless communication terminal or S
The IR has a small value and increases as it gets closer to the base station. Therefore, when it is assumed that communication is performed at the same transmission speed, it is considered that the transmission power that greatly affects the power consumption can secure an equivalent QoS with a smaller value as the transmission power approaches the base station. To be

FIG. 3 is a flow chart showing the flow of the control operation when the communication speed is changed to secure the remaining memory capacity regardless of the received power of the reference signal from the base station or the value of SIR, and FIG. 9 is a flowchart showing a flow of control operation in the case of changing both the communication speed and the exchange method in order to secure the remaining memory amount regardless of the received power of the reference signal from the base station or the value of SIR.

First, a description will be given with reference to FIG.

First, in step S301, the CPU 503 of the wireless communication apparatus detects the remaining memory capacity of the RAM 104 in which image information and audio information are stored. Next, in step S302, the remaining memory amount detected in step S301 is compared with the threshold ThM. here,
Assuming a digital camera application, the threshold value ThM is “memory full” by using a relatively large value in the continuous shooting (continuous shooting) mode and a relatively small value in the intermittent shooting mode. It is possible to reduce the possibility that shooting cannot be performed depending on the state. Further, not only the difference between the continuous shooting mode and the intermittent mode but also the difference between the high image quality mode and the low image quality mode, the same effect can be obtained by using the threshold value ThM having a relatively large value and the threshold value ThM having a relatively small value. Will be obtained.

As a result of comparison between the remaining memory capacity and the threshold ThM,
If the remaining amount of memory is larger than the threshold ThM, it means that the remaining amount of memory is sufficiently secured for the selected shooting mode, and the process proceeds to step S303, and the communication speed changing means of the wireless communication device is executed. To be done. On the contrary, if the memory remaining amount is smaller than the threshold ThM, it means that the memory remaining amount is not sufficiently secured for the selected shooting mode, and the process proceeds to step S310.

In step S303, C of the wireless communication device is
The PU 503 sends a control line 701 to the wireless unit 504.
A request signal is output to output the received power or SIR of the reference signal via. Next, in step S304, the reception power or SIR as a result of the request signal is output from the wireless unit 504, and the result is RAM1.
A determination is made as to whether or not the data has been stored in 04. If the data has arrived, the process proceeds to step S305, and if the data has not arrived, the process waits until it arrives.

In step S305, the wireless unit 50
It is determined whether the received power or SIR of the reference signal output from 4 is larger than the threshold Th1. If the received power or SIR of the reference signal is larger than the threshold Th1, the received power is sufficiently large, so that the high-speed first
It is considered that the transmission power within the allowable range is sufficient even if the data transmission at the communication speed is performed, and the image / sound transmission at the first communication speed is executed in step S306, and then the present processing operation is ended. Here, of course, when transmitting at the maximum communication speed, it means the first communication speed that requires transmission power within an allowable range, and it is of course possible to perform communication at the same communication speed or lower.

On the other hand, if the received power or SIR of the reference signal is smaller than the threshold Th1 in step S305, the process proceeds to step S307. Here, it is determined whether the received power or SIR of the reference signal is between the threshold values Th1 and Th2. The judgment result is “Ye
If s ", the process proceeds to step S308 and the image / sound transmission at the second communication speed is executed, and then this processing operation ends. If the determination result in step S307 is" No ", the reference Signal reception power or SIR
Is a value smaller than Th2, the process proceeds to step S309, and after the image / audio transmission at the third communication speed is performed, this processing operation is ended.

The flow shown in FIG. 3 above will be briefly described as follows.

When the wireless communication device (mobile station) is located relatively close to the base station and the reception power or SIR of the reference signal is well received, the high-speed communication is performed. Since the electric power does not increase, high speed communication can be performed by taking advantage of the location.

On the other hand, when the wireless communication device (mobile station) is located far from the base station, the received power or SIR of the reference signal is considerably small, so high-speed communication is not dared and low-speed communication speed is not dared. Settle in. Then, when high-speed communication is required, high-speed communication is performed after approaching the base station and the reception power or SIR of the reference signal becomes favorable.

However, when the wireless communication device (mobile station) is often located relatively far from the base station and the received power or SIR of the reference signal is often very small, low-speed communication is inevitable. As a result, the amount of image / sound data that has not been transmitted and is accumulated in the RAM 104 increases, and the remaining amount of memory decreases, which may hinder the next shooting. Becomes higher.

In order to prevent such a situation from occurring, in step S302, the remaining amount of memory is Th.
When the number is less than M, the process proceeds to step S310, and the image / sound transmission is executed at the first communication speed regardless of the received power of the reference signal output from the wireless unit 504 or the magnitude of SIR.

Therefore, when the remaining memory capacity becomes smaller than the threshold value ThM, when the wireless communication terminal (mobile station) happens to be located far away from the base station and the received power or SIR of the reference signal is small. However, it is based on the idea that image and sound transmission will be performed in order to reduce the amount of image and sound information stored in the memory as much as possible, by prioritizing the securing of memory over the reduction of power in preparation for the next shooting. .

Next, description will be made with reference to FIG.

Incidentally, steps S401, 402, 4 in FIG.
04 to 410 are steps S301 to S301 of FIG. 3 described above.
09, the description thereof is omitted, and only the processing unique to the flow of FIG. 4 will be described.

4 is different from FIG. 3 in that, when the remaining amount of the memory becomes smaller than the threshold ThM, the image / sound transmission is performed regardless of the received power of the reference signal from the base station or the magnitude of SIR. Not only that, in order to collectively transmit the data in a short time, the circuit switching system, which is a more efficient transmission system, is selected.

That is, when the remaining amount of the memory is larger than the threshold ThM in step S402, step S40.
After proceeding to step 3 and selecting the packet switching method, step S
In step 404, the CPU 503 of the wireless communication device outputs a request signal to the wireless unit 504 via the control line 701 so as to output the received power of the reference signal or the SIR. If the remaining amount of the memory is smaller than the threshold value ThM in step S402, the process proceeds to step S411, the image and sound transmission is performed by the circuit switching method, and then the present processing operation is ended.

The circuit switching system and the packet switching system each have the following features in general.

The advantage of the packet switching system is that no call connection time is required. When transmitting a small amount of data at time intervals, the communication cost is lower than that of the circuit switching method. The long distance communication costs are low because there is little difference in perspective. Further, as a disadvantage of the packet switching system, when a large amount of data is transmitted in a short time, the communication cost is higher than that of the circuit switching. Short-distance communication costs are high because there is little difference in perspective.

On the other hand, the advantage of the circuit switching system is that the effective transmission rate is higher than that of the packet switching system. When concentrated and transmitting a large amount of data in a short time, communication costs are lower than packet switching. Due to the large difference in perspective, short-distance communication costs are cheap. As a disadvantage of the circuit switching system, call connection time occurs. If there is a small amount of transmission data during call connection, communication costs will be higher than packet switching.

Since the circuit switching system and the packet switching system have the above-mentioned characteristics, the flow of FIG. 4 is performed in order to secure the memory area for the subsequent shooting as quickly as possible. In step S411
Although the circuit switching system is selected in, the user may select either the circuit switching system or the packet switching system according to the situation without being limited to the circuit switching system.

The object of the present invention is to supply a storage medium having a program code of software for realizing the functions of the above-described embodiment to a system or apparatus, and to supply the computer (or CPU or MPU of the system or apparatus).
It goes without saying that (etc.) can be achieved by reading and executing the program code stored in the storage medium.

In this case, the program code itself read from the storage medium realizes the functions of the above-described embodiments, and the storage medium storing the program code constitutes the present invention.

As a storage medium for supplying the program code, for example, a floppy (registered trademark) disk, a hard disk, a magneto-optical disk, a CD-RO.
M, CD-R, CD-RW, DVD-ROM, DVD-
RAM, DVD-RW, DVD + RW, magnetic tape, non-volatile memory card, ROM, etc. can be used.

Further, by executing the program code read by the computer, not only the functions of the above-described embodiment are realized, but also the OS (operating system) operating on the computer based on the instruction of the program code. It goes without saying that this also includes the case where the above) performs a part or all of the actual processing and the processing realizes the functions of the above-described embodiments.

Further, after the program code read from the storage medium is written in the memory provided in the function expansion board inserted into the computer or the function expansion unit connected to the computer, based on the instruction of the program code, It goes without saying that the case where the CPU or the like included in the function expansion board or the function expansion unit performs some or all of the actual processing and the processing realizes the functions of the above-described embodiments is also included.

[0079]

As described above, according to the present invention, it is possible to effectively use the memory and reduce the communication cost while maintaining the reduction of the power consumption.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a wireless communication device according to an embodiment of the present invention.

FIG. 2 is a diagram showing a configuration example of a network in which a wireless communication device according to an embodiment of the present invention is arranged.

FIG. 3 is a flowchart showing an operation flow when only a communication speed is changed in the wireless communication device according to the embodiment of the present invention.

FIG. 4 is a flowchart showing a flow of operations when changing both the communication speed and the exchange method in the wireless communication device according to the embodiment of the present invention.

FIG. 5 is a block diagram showing a configuration of a wireless communication device as a first conventional example.

FIG. 6 is a diagram showing a power saving effect in a wireless communication device as a first conventional example.

[Explanation of symbols]

501 battery 502 voltage detection circuit 503 CPU (central processing unit) 504 wireless unit 505 antenna 506 speaker 507 microphone 508 audio codec 509 data line 510 first control line 511 first signal line 512 second signal line 513 third Signal line 514 RAM (random access memory) 515 ROM (read only memory) 516 Second control line 517 Display + BV Output voltage of battery 501 (that is, operating voltage inside the device) 518 Fourth signal line 519 Fifth Signal line 520 Camera 521 Sixth signal line 522 Keyboard 201 MS (Mobile Station) 202 BTS (Base Transceiver)
System) 203 MCC (Mobile Communica)
network control unit 204 network 205 MCC (Mobile Communica)
Edition Control Center) 206 BTS (Base Transceiver)
System) 207 MS (Mobile Station) 208 BTS (Base Transceiver)
System) 209 BTS (Base Transceiver)
System)

Claims (25)

[Claims] 1. A received power detecting means for detecting a received power of an incoming reference signal, a memory remaining amount detecting means for detecting a remaining amount of a memory for storing information to be transmitted, and a received power detecting means for detecting the remaining amount. A wireless communication device comprising: a changing unit that changes at least one of a communication speed and an exchange method based on the received power received and the remaining memory amount detected by the remaining memory amount detecting unit. 2. The changing means changes the communication speed based on the received power detected by the received power detecting means and the memory remaining amount detected by the memory remaining amount detecting means. The wireless communication device according to Item 1. 3. The changing unit changes the exchange method based on the received power detected by the received power detecting unit and the remaining memory amount detected by the remaining memory amount detecting unit. The wireless communication device according to Item 1. 4. The changing unit changes the communication speed and the exchange method based on the received power detected by the received power detecting unit and the remaining memory amount detected by the remaining memory amount detecting unit. The wireless communication device according to claim 1, wherein the wireless communication device is a wireless communication device. 5. The SIR (= Signal of the incoming reference signal)
to Interference Ratio: SIR detection means for detecting a desired wave-to-interference signal power ratio), and a memory remaining amount detection means for detecting a remaining amount of memory for storing information to be transmitted,
Wireless communication comprising: a changing unit that changes at least one of a communication speed and an exchange method based on the SIR detected by the SIR detecting unit and the remaining memory amount detected by the remaining memory amount detecting unit. apparatus. 6. The changing means changes the communication speed based on the SIR detected by the SIR detecting means and the memory remaining amount detected by the memory remaining amount detecting means. The wireless communication device according to. 7. The changing unit changes the exchange method based on the SIR detected by the SIR detecting unit and the memory remaining amount detected by the memory remaining amount detecting unit. The wireless communication device according to. 8. The changing unit changes the communication speed and the exchange method based on the SIR detected by the SIR detecting unit and the remaining memory amount detected by the remaining memory amount detecting unit. The wireless communication device according to claim 5. 9. A control method for controlling a wireless communication device, comprising: a received power detecting step of detecting received power of an incoming reference signal; and a remaining amount of a memory for storing information to be transmitted. A memory remaining amount detecting step; a changing step of changing at least one of a communication speed and an exchange method based on the received power detected by the received power detecting step and the memory remaining amount detected by the memory remaining amount detecting step. A method for controlling a wireless communication device, comprising: 10. The changing step changes the communication speed based on the received power detected by the received power detecting step and the memory remaining amount detected by the memory remaining amount detecting step. Item 10. A method for controlling a wireless communication device according to Item 9. 11. The exchange method is changed in the changing step based on the received power detected by the received power detecting step and the remaining memory amount detected by the remaining memory amount detecting step. Item 10. A method for controlling a wireless communication device according to Item 9. 12. The changing step includes changing a communication speed and an exchange method based on the received power detected by the received power detecting step and the memory remaining amount detected by the memory remaining amount detecting step. The method for controlling a wireless communication apparatus according to claim 9, wherein the method is for controlling a wireless communication apparatus. 13. A control method for controlling a wireless communication device, comprising: SIR (= Signal to Signal) of an incoming reference signal.
Interference Ratio: SIR detection step for detecting desired wave-to-interference signal power ratio), memory remaining amount detection step for detecting remaining amount of memory for storing information to be transmitted, and SIR detected by the SIR detection step.
And a changing step of changing at least one of a communication speed and an exchange method based on the remaining memory amount detected by the remaining memory amount detecting step. 14. The communication speed is changed in the changing step based on the SIR detected in the SIR detecting step and the memory remaining amount detected in the memory remaining amount detecting step. A method for controlling a wireless communication device according to claim 1. 15. The exchange method is changed in the changing step based on the SIR detected by the SIR detecting step and the memory remaining amount detected by the memory remaining amount detecting step. A method for controlling a wireless communication device according to claim 1. 16. The changing step changes the communication speed and the exchange method based on the SIR detected by the SIR detecting step and the memory remaining amount detected by the memory remaining amount detecting step. Claim 1
4. The method for controlling the wireless communication device according to item 3. 17. A computer-readable control program for controlling a wireless communication device, comprising: a received power detecting step of detecting received power of an incoming reference signal; and a memory remaining for storing information to be transmitted. At least one of the communication speed and the exchange method is changed based on the memory remaining amount detecting step for detecting the amount, the received power detected by the received power detecting step, and the memory remaining amount detected by the memory remaining amount detecting step. A control program for a wireless communication device, comprising a program code for causing a computer to execute the changing step. 18. The communication speed is changed in the changing step based on the received power detected in the received power detecting step and the remaining memory amount detected in the remaining memory amount detecting step. Item 18. A control program for a wireless communication device according to Item 17. 19. The exchange method is changed in the changing step based on the received power detected by the received power detecting step and the remaining memory amount detected by the remaining memory amount detecting step. Item 18. A control program for a wireless communication device according to Item 17. 20. The changing step includes changing the communication speed and the exchange method based on the received power detected by the received power detecting step and the memory remaining amount detected by the memory remaining amount detecting step. The control program for the wireless communication device according to claim 17, wherein the control program is for a wireless communication device. 21. A computer-readable control program for controlling a wireless communication device, comprising: SIR (= Signal to Interference Rati) of an incoming reference signal.
o: Desired wave to interference signal power ratio), an SIR detecting step, a memory remaining amount detecting step of detecting a remaining amount of memory for storing information to be transmitted, and an SIR detected by the SIR detecting step. A wireless communication device comprising a program code for causing a computer to execute a changing step of changing at least one of a communication speed and an exchange method based on the remaining memory amount detected by the remaining memory amount detecting step. Control program. 22. The communication speed is changed in the changing step based on the SIR detected in the SIR detecting step and the memory remaining amount detected in the memory remaining amount detecting step. A control program for the wireless communication device according to. 23. The changing method changes the exchange method based on the SIR detected by the SIR detecting step and the memory remaining amount detected by the memory remaining amount detecting step. A control program for the wireless communication device according to. 24. The changing step changes the communication speed and the exchange method based on the SIR detected by the SIR detecting step and the memory remaining amount detected by the memory remaining amount detecting step. Claim 2
1. A control program for the wireless communication device according to 1. 25. A storage medium storing the control program for the wireless communication device according to claim 17.