JP2010098494A - Wireless communication system and its power-saving control method, and wireless communication device and method of controlling the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To achieve suitable power-saving control by providing a mechanism which has a sleep period and an active period that a user application determines in an environment wherein there is not a communication partner except an opposite communication device. <P>SOLUTION: A wireless communication device shares period information for specifying the sleep period and active period with an external communication device, and performs mutually synchronized power-saving communication operation. The wireless communication device receives a designation of a sleep period and an active period in the power-saving operation from a host control unit above a communication control layer, transmits a message for reporting the designation to the external communication device, and receives acknowledge for the transmission of the message from the external communication device. Then, when the sleep period included in the designation is shorter than a predetermined period, power-saving operation complying with the designation is immediately performed and when the sleep period included in the designation is equal to or longer than the predetermined period, power-saving operation complying with the designation is performed after the acknowledge is received. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a power saving control of a communication function unit in a wireless communication system, particularly a close proximity wireless communication system.

  Many mobile devices operate on batteries, and a mechanism that reduces power consumption is used to extend the operating time as much as possible. For example, when a mobile phone is waiting for an incoming call, the radio unit is not always turned on, but the radio unit is turned on intermittently according to the period of the notification signal of the base station. Yes. Further, even during communication, the power consumption is reduced by intermittently turning on the wireless unit during a period of low communication frequency as described above.

  In many wireless communication systems such as a wireless LAN, as in Patent Document 1, a notification of transition to a low power consumption mode and confirmation from the other party are received and the transition to the low power consumption mode is made. However, as shown in FIG. 9, there is also a method that shifts to a sleep state and realizes a low power consumption mode without receiving confirmation from the other party.

  FIG. 9 is a sequence diagram illustrating a mechanism for reducing power consumption by intermittently turning on the wireless unit between the communication device A and the communication device B.

  When the communication frequency decreases, the communication device A transmits a low power consumption mode transition notification M1001 to the communication device B and enters the low power consumption mode. In the low power consumption mode, the power of the CPU controlling the wireless unit is reduced, and the sleep state in which no power is supplied to the wireless unit and the active state that operates with normal power are switched at regular intervals. Communication with the communication device B can be performed in the active state, but communication with the communication device B cannot be performed in the sleep state. When the communication device A wants to transmit data to the communication device B in the low power consumption mode, the data is stored until the communication device B becomes active, and the data is transmitted to the communication device B when it becomes active. To do.

  Upon receiving the low power consumption mode transition notification M1001 from the communication device A, the communication device B recognizes that the communication device A has entered the low power consumption state. The communication device B recognizes the cycle of the sleep state and the active state of the communication device A, and when transmitting data to the communication device A, transmits the data during the period in which the communication device A is in the active state.

In general, as a method of sharing information on a sleep period and an active period for power saving control, there is a method in which a neighboring communication device is informed using a wide-area notification message such as a beacon (Non-Patent Document 1). In addition, there is a method in which a communication device registers a communication partner as a connection partner and then assigns control signal monitoring timing information (active period) from the communication partner (Non-Patent Document 2).
JP 2006-093788 A IEEE 802.11 RCR-STD28

  In general, in power saving control that is assumed to be applied to a network to which a plurality of communication devices belong, it is necessary to follow a sleep period / active period set on the network function side. In this case, although the set sleep period / active period is appropriate as a communication protocol alone, it is not necessarily an appropriate period from the viewpoint of a communication service in which a higher-level user application is combined.

  The present invention has been made in view of the above problems. The present invention provides a mechanism for sharing a sleep period / active period determined by a user application in an environment where there is no communication partner other than the opposite communication device, such as a close proximity wireless communication environment, and realizes suitable power saving control The purpose is to do.

In order to achieve the above object, a power saving control method according to an aspect of the present invention includes:
A wireless communication system in which a first communication device and a second communication device share period information for specifying a sleep period and an active period, and perform power-saving communication operations that alternately repeat a sleep state and an active state in synchronization with each other A power saving control method in
In the first communication device, an accepting step of receiving an instruction of a sleep period and an active period in a power saving communication operation from a higher-order control unit higher than the communication control layer;
A transmission step of transmitting a message for notifying the second communication device of the instruction received in the reception step;
In the second communication device, a reply step of returning an acknowledge corresponding to the message transmitted in the transmission step to the first communication device;
Executing the power-saving communication operation based on an instruction of a sleep period and an active period included in the message;
In the first communication device, when a sleep period included in the instruction is shorter than a predetermined period, a power-saving communication operation according to a sleep period and an active period included in the instruction is immediately executed, and the instruction A step of executing a power-saving communication operation according to the sleep period and the active period included in the instruction after waiting for the receipt of an acknowledge by the reply step when the included sleep period is equal to or longer than the predetermined period And have.

A wireless communication system according to another aspect of the present invention that achieves the above object has the following configuration. That is,
A wireless communication system in which a first communication device and a second communication device share period information for specifying a sleep period and an active period, and perform power-saving communication operations that alternately repeat a sleep state and an active state in synchronization with each other Because
In the first communication device, accepting means for accepting an instruction of a sleep period and an active period in a power-saving communication operation from an upper control unit higher than the communication control layer;
Transmitting means for transmitting a message for notifying the second communication device of the instruction accepted by the accepting means;
In the second communication device, a reply means for returning an acknowledge corresponding to the message transmitted by the transmission means to the first communication device;
Means for performing the power saving communication operation based on an instruction of a sleep period and an active period included in the message;
In the first communication device, when a sleep period included in the instruction is shorter than a predetermined period, a power-saving communication operation according to a sleep period and an active period included in the instruction is immediately executed, and the instruction Means for executing a power-saving communication operation in accordance with the sleep period and the active period included in the instruction after receiving an acknowledge by the reply means when the included sleep period is equal to or longer than the predetermined period With.

A wireless communication apparatus according to another aspect of the present invention that achieves the above object has the following configuration. That is,
A wireless communication device that shares period information that specifies a sleep period and an active period with an external communication device, and performs a power-saving communication operation that alternately repeats a sleep state and an active state in synchronization with each other,
An accepting means for accepting an instruction of a sleep period and an active period in a power-saving communication operation from an upper control unit higher than the communication control layer;
Transmitting means for transmitting a message for notifying the external communication device of the instruction accepted by the accepting means;
Receiving means for receiving an acknowledgment for transmission of the message from the external communication device;
When the sleep period included in the instruction is shorter than the predetermined period, the power saving communication operation according to the sleep period and the active period included in the instruction is immediately executed, and the sleep period included in the instruction is the predetermined period. And executing means for executing a power-saving communication operation in accordance with the sleep period and the active period included in the instruction after waiting for reception of the acknowledge by the receiving means.

Furthermore, a method for controlling a wireless communication apparatus according to another aspect of the present invention that achieves the above object is as follows:
A method for controlling a wireless communication device that shares period information for specifying a sleep period and an active period with an external communication device and performs power-saving communication operations that alternately repeat a sleep state and an active state in synchronization with each other. There,
An accepting step of accepting an instruction of a sleep period and an active period in a power-saving communication operation from an upper control unit higher than the communication control layer;
A transmission step of transmitting a message for notifying the external communication device of the instruction received in the reception step;
A receiving step of receiving an acknowledgment for the transmission of the message from the external communication device;
When the sleep period included in the instruction is shorter than the predetermined period, the power saving communication operation according to the sleep period and the active period included in the instruction is immediately executed, and the sleep period included in the instruction is the predetermined period. And the execution step of executing the power saving communication operation according to the sleep period and the active period included in the instruction after waiting for the receipt of the acknowledge in the reception step.

  According to the present invention, according to the length of the requested sleep period, whether or not the reception result of the response to the power saving mode request message from the opposite communication device is required as a condition for transition to the sleep period. Determined. Therefore, it is possible to efficiently prevent a long-time mismatch in the operation mode state with the opposite communication device when the message is lost due to a communication data error or the like.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings.

<First Embodiment>
FIG. 1 is a system configuration diagram of the present invention. This system includes a device A 101 as a first communication device, a device B 102 as a second communication device, and a display 104. Device A 101 and device B 102 are connected by, for example, close proximity wireless communication 103. Examples of the proximity wireless communication 103 include non-contact IC card wireless communication using electromagnetic induction, NFC (Near Field Communication), communication using an induction electric field, and the like. The display 104 communicates with the device A101 via the device B102. An adapter cable 105 is connected between the display 104 and the device B102.

  FIG. 2 is a block diagram showing a configuration example of the device A101 and the device B102 in the embodiment of the present invention. FIG. 3 is a transmission / reception sequence diagram schematically showing the relationship between the operation mode transition and the control message of the close proximity wireless transfer system employed in the present embodiment.

  A communication control unit 201 controls the device A101. The communication control unit 201 is usually composed of a CPU and a memory. Reference numeral 202 denotes a proximity wireless communication unit that performs the proximity wireless communication 103. A mode storage unit 203 stores mode information indicating whether the device A 101 is in a standby mode (30, 34), a normal mode (31, 33), or a power save mode (32). A power save mode transition notification transmission unit 204 transmits a sleep information message for notifying the device B 102 of the occurrence period of the sleep state and the active state via the proximity wireless communication unit 202 when shifting to the power save mode. To do. Reference numeral 205 denotes a near field communication control unit that controls the near field communication unit 202.

  Reference numeral 206 denotes a low power consumption mode control unit (power save mode control unit) that performs control in the power save mode. Reference numeral 207 denotes a sleep control unit that controls the sleep state. Reference numeral 208 denotes an active control unit that controls the active state. In the sleep state, the CPU of the communication control unit 201 operates at a low speed, or the power supply to the close proximity wireless communication unit 202 is stopped to reduce power consumption compared to the active state. A state storage unit 209 stores state information indicating whether the device is in a sleep state or an active state. An interval time storage unit 210 stores an interval time indicating the time in the sleep state. Reference numeral 220 denotes a link confirmation cycle storage unit that stores cycle information indicating a cycle in which the presence check of the opposing communication device within the communicable distance is performed by exchanging search / response messages.

  In the power save mode (32, 37), the sleep state and the active state are periodically switched, and when the interval time elapses after the transition to the sleep state (when the sleep period elapses), the transition is made to the active state. In the active state, communication with the counterpart device can be performed via the close proximity wireless communication unit 202. After the transition to the active state, the transition to the sleep state is made again after a certain time has passed (when the active period has passed). The period information indicating the sleep period and the active period is shared between the device A 101 and the device B 102. Then, a power saving communication operation (operation in the power save mode) synchronized with each other is executed.

  Next, the configuration of the device B102 will be described. Reference numeral 211 denotes a communication control unit of the device B102, which is usually composed of a CPU and a memory. A proximity wireless communication unit 212 performs the proximity wireless communication 103. Reference numeral 213 denotes an interface unit that communicates with the main body (the display 104 in the present embodiment) via the adapter cable 105.

  Reference numeral 214 denotes a power save mode transition confirmation notification transmitting unit that transmits the power save mode transition notification from the device A 101 to the device A 101 via the proximity wireless communication unit 212. Reference numeral 215 denotes a proximity wireless communication control unit that controls the proximity wireless communication unit 212. Reference numeral 216 denotes an interval time storage unit that stores an interval time indicating a time during which the device A 101 is in the sleep state. Reference numeral 217 denotes an interface control unit that controls the interface unit 213. Reference numeral 221 denotes a link confirmation cycle storage unit that stores cycle information indicating a cycle for performing the presence confirmation of the opposing communication device within the communicable distance by exchanging search / response messages.

  FIG. 4 is a functional configuration layer diagram of the communication device according to the present embodiment. 5 and 6 are transmission / reception sequence diagrams showing the relationship between the transition to the power save mode and the return from the power save mode shown in FIG. 3 and the control messages. FIG. 8 is a flowchart for explaining processing when a power save mode start request is received from the host control unit of the communication control unit equipped with the function according to the present embodiment. Hereinafter, the first embodiment of the present invention based on the system configuration diagram of FIG. 1, the block diagram of FIG. 2, the functional configuration layer diagram of FIG. 4, the sequence charts of FIGS. 3, 5, and 6, and the flowchart of FIG. Will be described.

  Assume that the device A 101 and the device B 102 in the standby mode (30, 35) exist in the proximity state. In this state, when a connection request (300) is issued from the device A101 (301, 302), it is received by the device B102, and connection acceptance (303) is returned, both devices are in the normal mode (31, 36). Migrate to In the normal mode, data communication is performed by data transmission and acknowledgment (Ack) (303, 304, 305, 306, 307, 311, 312). In the normal mode (for example, 33, 38), when a release request is instructed from the user application 402, a release request is issued from the communication control unit 201 (313), and both devices shift to the standby mode (34, 39). To do. There is no confirmation of receipt for this release request. Note that when the device B 102 receives the link control message between the communication devices, the device B 102 determines whether or not it is necessary to return the reception result according to the type of the received message. In other words, acceptance (Ack) is returned for connection requests (301, 302) and sleep information (503, etc.), and acceptance is not returned for release requests (313).

  When there is no data to be transmitted by the user application 402 during operation in the normal mode (31, 33), the user application 402 is instructed to shift to the power save mode (308). Both devices enter the power save mode (32, 37) through the procedure described later with reference to FIGS.

  As shown in FIG. 4, in the power saving instruction 405 from the user application 402, the application can set a desired sleep period (403) and active period (404) as institution information. The system that has received this instruction from the user application executes the power save sequence (309) shown in FIG. Note that the user application 402 functions as an upper control unit that is higher than the communication control layer including the communication control layer 401 and the physical layer 400.

  Hereinafter, with reference to FIGS. 5, 6, and 8, the operation for shifting to the power saving mode and the canceling operation according to the present embodiment will be described. The device A101 transmits a sleep information message to notify the device B102 which is the opposite device of the sleep period and the active period specified by the power save instruction (500, 600) (step 801). The transmission of the sleep information message is indicated by 501, 503, 508, 601, 604, 609, and 801 in FIGS.

  Here, as a problem, when the sleep information message disappears due to burst noise or the like (501, 601), the device B102 cannot know the designated sleep period and active period. As a means for solving this problem, the procedure shown in the message sequence of FIG. 5 is effective. That is, the method of entering the sleep period (505) of the power mode save (51) from the normal mode (50) when the reception confirmation message is received (504) after the transmission of the sleep information message (501, 503) is effective. is there.

  However, if the sleep period is shorter than the continuous transmission period of the search message for checking the link state, the search message is being retransmitted for checking the link state (not shown) even if the device state mismatch occurs. Can be recovered. In view of such an event, in the present embodiment, the notified sleep period is compared with a predetermined specified value (in this embodiment, a link state confirmation cycle in close proximity wireless communication) (step 802). If the sleep period is equal to or greater than the specified value, a sleep confirmation period (505) is entered after receiving a reception confirmation message (504) that is a reply to the sleep information message (step 802 (YES) → 803 → 804 (YES) → 807). On the other hand, if the sleep period is less than the specified value, the sleep period starts immediately (step 802 (NO) → 807). That is, the link state confirmation cycle in close proximity wireless communication (link protection period = device search message transmission period × specified number of times for continuous transmission of the search message) and the sleep period are compared to determine how to enter the power save mode. Control. This is shown in FIG. That is, immediately after the transmission of the sleep information (601), the normal mode (60) shifts to the power save mode (61), and the device A101 enters the sleep state (602).

  In step 803, the waiting time for reception of the reception confirmation message is set in the sleep information Ack timer, and the timer is started. If the reception confirmation message (sleep information Ack) is received within this waiting time, the process proceeds to step 807 to shift to the sleep period (step 804 (YES)). If the reception confirmation message cannot be received before the sleep information Ack timer expires, the processing ends as one processing unit ends (step S806). Then, the sleep information is transmitted again (503).

  In step 807, the communication control unit 201 sets and starts the sleep period timer to the instructed sleep period, and shifts to the sleep period. The sleep period continues until the sleep period timer expires (during NO in step 809) unless power save cancellation is requested.

  When the sleep period expires (step 809 (YES)), the process proceeds to the active period (507, 603, 607) (step 810). In step 810, the communication control unit 201 sets the active period timer to the active period indicated by the instruction 405 and starts. During this active period (during NO at step 813), communication between both devices is possible. Also, upon receiving an active request (514, 612) from the device B102 during this active period, the communication control unit 201 returns a corresponding acknowledge (516, 614) and returns to the normal mode (not shown). Thus, one processing unit is completed.

If the active period expires without receiving an active request from the device B 102 during the active period, the sleep information message is transmitted again (step 813 (YES) → 801). This situation is shown in 508, 604, and 609 in FIG. In addition, with reference to the flowchart of FIG.
・ After “active period has expired” (step 813 → 801), it is determined that it is necessary to receive Ack (step 801 → 802 → 803) by transmitting sleep information,
・ Start the Ack wait timer (step 803),
-When Ack is received (510) within this period, the sleep period timer is started (step 804 → 807), and the sleep state is entered.
It becomes. Thus, the sleep period and the active period are alternately repeated (505 → 507 → 511, 602 → 603 → 605 → 607 → 611). The device B102 executes a power save mode in which the sleep state and the active state are alternately repeated in synchronization with the device A101, as shown in FIGS.

  It should be noted that the power saving mode cancellation instruction by the user application 402 that has instructed the instruction 405 is valid in any state of the sleep period (505, 511), the active period (507, 515), and the Ack waiting period (502). It is. This process is illustrated by steps 808, 812, 805 in FIG. The power save mode cancel request (310, 513, 514, 612) generated from the device B102 is accepted during the active period (step 812).

  As described above, according to the first embodiment, whether to wait for the reception result of the power saving mode request message from the opposite communication device according to the length of the sleep period requested from the user application 402 as the upper control unit. It is determined whether or not. That is, it is determined according to the length of the requested sleep period whether it is necessary to receive a power saving mode request message from the opposite communication device as a condition for transition to the sleep period. By such processing, it is possible to prevent a long-time mismatch in the operation mode state with the opposite communication device at the time of message loss due to a communication data error or the like.

<Second Embodiment>
Next, a second embodiment will be described. In the second embodiment, a configuration will be described in which the length of the sleep period / active period can be changed during the operation in the power save mode.

  FIG. 7 is a message sequence chart when the device A 101, which is a close proximity wireless communication device in the power save mode operation, receives a power save request (707) in which a new sleep period / active period is specified. FIG. 7 shows the relationship between the new power save request (707) and the change of the sleep period / active period.

  First, the communication control unit 201 receives a power save mode start request (700) from the host control unit (for example, the user application 402) during the normal mode (70), and operates in the power save mode 1 (71). It is carried out. Here, the power mode start request (700) includes designation of the sleep period 1 (702) and the active period 1 (703).

  In the second embodiment, it is assumed that the sleep period is less than the specified value resulting from the search cycle for checking the link state (NO in step 802). That is, it is determined that the reception confirmation of the sleep information message is unnecessary, and control is performed so as to shift to the sleep mode immediately after the sleep information is transmitted.

  The upper control unit (user application 402) of the device A101 operating in the power save mode 1 detects a change in the time required for the upper application process and the like, and it is necessary to update at least one of the sleep period 1 and the active period 1 or not. Determine whether. If it is determined that it is necessary, an update instruction is issued by executing a power save request (707) including designation of a new sleep period / active period.

  The communication control unit 201 of the device A that has received the power save request (707) for the new sleep period / active period sleep information including changed period information after the expiration of the current or next active period 1 (708). (709) is transmitted to an external communication device. This sleep information (709) includes designation of a new sleep period 2 (711) and / or active period 2 (714). In accordance with this new period, the device A 101 updates the sleep period and the active period, and executes the power save mode operation. Similarly, the device B102, which is an external communication device, also updates the sleep period and the active period in accordance with this designation, and executes the operation in the power save mode. The device B 102 also recognizes the period change in power save from the received sleep information (709) (712), and executes the power save mode using the updated sleep period and active period (713, 716).

  As described above, according to the second embodiment, it is possible to realize mode update (sleep period / active period update) during the power save mode operation without transition to the normal mode. Therefore, appropriate power management according to the processing status of the host controller can be realized.

<Third Embodiment>
It goes without saying that the object of the present invention can also be achieved when a computer of a system or apparatus reads and executes the program code from a recording medium that records the program code of software that implements the functions of the above-described embodiments. Here, as a computer, CPU or MPU is typical.

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

  Examples of the computer-readable storage medium for supplying the program code include the following. That is, a flexible disk, hard disk, optical disk, magneto-optical disk, CD-ROM, CD-R, magnetic tape, nonvolatile memory card, ROM, DVD, or the like can be used.

  In the first embodiment and the second embodiment, an example in which application to a close proximity wireless communication system is used has been described. However, application to power saving control of a peer-to-peer communication system such as optical communication is also possible.

It is a figure which shows the system configuration example of this embodiment. It is a block diagram which shows the function structural example of the near field communication apparatus of this embodiment. It is a figure which shows the example of a sequence of the near field communication link control of this embodiment. It is a figure which shows the function layer structure of this embodiment, and the structural example of a control primitive. It is a figure which shows the example of a sequence chart of the power saving control (sleep time> device search period) of 1st Embodiment. It is a figure which shows the power-saving control (sleep time <device search cycle) sequence chart example of 1st Embodiment. It is a figure which shows the power saving control sequence chart example of 2nd Embodiment. It is a flowchart which shows the power saving control in a near field communication apparatus in this embodiment. It is the sequence diagram which showed the mechanism in the case of reducing power consumption by turning on a radio | wireless part intermittently between the communication apparatus A and the communication apparatus B.

Claims (8)

A wireless communication system in which a first communication device and a second communication device share period information for specifying a sleep period and an active period, and perform power-saving communication operations that alternately repeat a sleep state and an active state in synchronization with each other A power saving control method in
In the first communication device, an accepting step of accepting an instruction of a sleep period and an active period in a power-saving communication operation from an upper control unit higher than the communication control layer;
A transmission step of transmitting a message for notifying the second communication device of the instruction received in the reception step;
In the second communication device, a reply step of returning an acknowledge corresponding to the message transmitted in the transmission step to the first communication device;
Executing the power-saving communication operation based on an instruction of a sleep period and an active period included in the message;
In the first communication device, when a sleep period included in the instruction is shorter than a predetermined period, a power-saving communication operation according to a sleep period and an active period included in the instruction is immediately executed, and the instruction A step of executing a power-saving communication operation in accordance with the sleep period and the active period included in the instruction after waiting for the receipt of an acknowledge by the return step when the included sleep period is equal to or longer than the predetermined period A power saving control method comprising:   The power saving control method according to claim 1, wherein the predetermined period is a period of link state confirmation in wireless communication. In the first communication apparatus, when at least one of a sleep period and an active period is changed by the host controller during execution of the power saving communication operation, an update instruction indicating the changed sleep period and active period Sending a message notifying
Continuing the power-saving communication operation using the changed sleep period and active period;
The said 2nd communication apparatus is further provided with the process of changing the said power saving communication operation | movement using the said changed sleep period and active period according to reception of the said update instruction | indication. Or the power saving control method according to 2; A wireless communication system in which a first communication device and a second communication device share period information for specifying a sleep period and an active period, and perform power-saving communication operations that alternately repeat a sleep state and an active state in synchronization with each other Because
In the first communication device, accepting means for accepting an instruction of a sleep period and an active period in a power-saving communication operation from an upper control unit higher than the communication control layer;
Transmitting means for transmitting a message for notifying the second communication device of the instruction accepted by the accepting means;
In the second communication device, a reply means for returning an acknowledge corresponding to the message transmitted by the transmission means to the first communication device;
Means for performing the power saving communication operation based on an instruction of a sleep period and an active period included in the message;
In the first communication device, when a sleep period included in the instruction is shorter than a predetermined period, a power-saving communication operation according to a sleep period and an active period included in the instruction is immediately executed, and the instruction Means for executing a power-saving communication operation in accordance with the sleep period and the active period included in the instruction after receiving an acknowledge by the reply means when the included sleep period is equal to or longer than the predetermined period A wireless communication system comprising: A wireless communication device that shares period information for specifying a sleep period and an active period with an external communication device, and performs a power-saving communication operation that alternately repeats a sleep state and an active state in synchronization with each other,
An accepting means for accepting an instruction of a sleep period and an active period in a power-saving communication operation from an upper control unit higher than the communication control layer;
Transmitting means for transmitting a message for notifying the external communication device of the instruction accepted by the accepting means;
Receiving means for receiving an acknowledgment for transmission of the message from the external communication device;
When the sleep period included in the instruction is shorter than the predetermined period, the power saving communication operation according to the sleep period and the active period included in the instruction is immediately executed, and the sleep period included in the instruction is the predetermined period. An execution means for executing a power-saving communication operation according to a sleep period and an active period included in the instruction after waiting for reception of the acknowledge by the reception means. A wireless communication device. A method for controlling a wireless communication device that shares period information for specifying a sleep period and an active period with an external communication device and performs power-saving communication operations that alternately repeat a sleep state and an active state in synchronization with each other. There,
An accepting step of accepting an instruction of a sleep period and an active period in a power-saving communication operation from an upper control unit higher than the communication control layer;
A transmission step of transmitting a message for notifying the external communication device of the instruction received in the reception step;
A receiving step of receiving an acknowledgment for the transmission of the message from the external communication device;
When the sleep period included in the instruction is shorter than the predetermined period, the power saving communication operation according to the sleep period and the active period included in the instruction is immediately executed, and the sleep period included in the instruction is the predetermined period. And executing the power-saving communication operation according to the sleep period and the active period included in the instruction after waiting for receipt of the acknowledge in the reception process. A method for controlling a wireless communication apparatus.   A program for causing a computer to execute the control method according to claim 6.   A computer-readable storage medium storing a program for causing a computer to execute the control method according to claim 6.

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