JP2013026965A - Wireless base station device, wireless terminal device, communication control method, and communication control program - Google Patents

Abstract

Power consumption can be suppressed.
A radio base station apparatus enters a dormant state when the radio base station apparatus is in a power saving mode. The radio base station apparatus transmits a beacon signal including base station mode information indicating the state of the radio base station apparatus. The base station mode information is information indicating that the own apparatus is in the power saving mode. The wireless terminal device determines its own state based on the base station mode information.
[Selection] Figure 1

Description

  The present invention relates to a radio base station apparatus, a radio terminal apparatus, a communication control method, and a communication control program.

The wireless terminal device has a power saving mode in which the awake state and the sleep state are periodically repeated. As for the radio base station apparatus, a technique described in Patent Document 1 is known.
FIG. 18 is an explanatory diagram for explaining intermittent communication according to the prior art.
The radio base station apparatus AP transmits a control signal s121 for prohibiting transmission of the radio terminal apparatus STA after transmitting a DTIM (delivery traffic indication message) beacon signal s111. When the sleep period of the radio base station AP is longer than the upper limit of the transmission prohibition period, the sleep period of the radio base station apparatus AP is divided, and the control signal s122 is transmitted for each divided base station sleep period. The radio base station apparatus AP shifts to the sleep state during the sleep period, and shifts to the awake state after the sleep period elapses. In the transmission prohibition period added to the control signals s121 and s122, the wireless terminal device STA waits without transmitting even if a transmission signal is generated.

JP 2010-193290 A

  However, in the communication according to the related art, the radio base station apparatus transmits a control signal in addition to the beacon signal. The wireless terminal device is in an awake state until a control signal is received, and has a disadvantage of wasting power.

  The present invention has been made in view of the above points, and provides a radio base station apparatus, a radio terminal apparatus, a communication control method, and a communication control program capable of suppressing power consumption.

  (1) Further, according to one aspect of the present invention, in the above-described radio base station apparatus, when the own apparatus is in a power saving mode, a communication unit that is in a dormant state and base station mode information indicating the state of the own apparatus And the base station mode information is information indicating that the own apparatus is in a power saving mode.

  (2) Further, according to one aspect of the present invention, in the above-described radio base station apparatus, a terminal management unit that manages terminal state information indicating a state of the wireless terminal apparatus, and the terminal state information includes states of all wireless terminal apparatuses And a control unit that determines the state of the own apparatus to the power saving mode when indicating that the power saving mode is in the power saving mode.

  (3) In addition, according to one aspect of the present invention, a receiving unit that receives a beacon signal including base station mode information indicating a state of a wireless base station device, and the state of the own device are determined based on the base station mode information. A wireless terminal device.

  (4) According to another aspect of the present invention, the wireless terminal device receives a beacon signal including base station mode information indicating a state of the wireless base station device, and the wireless terminal device includes the base station mode information in the base station mode information. And a process for determining the state of the own apparatus based on the communication control method.

  (5) Further, according to one aspect of the present invention, the computer of the wireless terminal device is configured to receive a beacon signal including base station mode information indicating the state of the wireless base station device based on the base station mode information. A communication control program for executing a means for determining the state of an apparatus.

  According to the present invention, power consumption can be suppressed.

It is explanatory drawing for demonstrating an example of the state of intermittent communication and each apparatus which concerns on embodiment of this invention. 1 is a schematic diagram showing a wireless communication system according to a first embodiment of the present invention. It is a schematic block diagram which shows the structure of the radio base station apparatus which concerns on this embodiment. It is a schematic block diagram which shows the structure of the radio | wireless terminal apparatus which concerns on this embodiment. It is the schematic which shows an example of the frame structure of the beacon signal which concerns on this embodiment. It is a flowchart which shows an example of operation | movement of the radio base station apparatus which concerns on this embodiment. It is a flowchart which shows an example of operation | movement of the STA management part which concerns on this embodiment. It is a flowchart which shows an example of operation | movement of the radio | wireless terminal apparatus which concerns on this embodiment. It is the schematic which shows an example of the relationship between the intermittent communication which concerns on this embodiment, and the state of a wireless base station apparatus. It is the schematic which shows an example of the relationship between the intermittent communication which concerns on this embodiment, and the state of each apparatus. It is the schematic which shows the radio | wireless communications system which concerns on the 2nd Embodiment of this invention. It is a schematic block diagram which shows the structure of the radio base station apparatus which concerns on this embodiment. It is a flowchart which shows an example of operation | movement of the radio base station apparatus which concerns on this embodiment. It is the schematic which shows the radio | wireless communications system which concerns on the 3rd Embodiment of this invention. It is a schematic block diagram which shows the structure of the radio base station apparatus which concerns on this embodiment. It is a flowchart which shows an example of operation | movement of the radio base station apparatus which concerns on this embodiment. It is a flowchart which shows an example of another operation | movement of the radio | wireless terminal apparatus which concerns on this embodiment. It is explanatory drawing for demonstrating the intermittent communication which concerns on a prior art.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is an explanatory diagram for explaining an example of intermittent communication and a state of each device according to the embodiment of the present invention. Here, intermittent communication refers to communication in which either or both of the wireless base station device AP and the wireless terminal device STA repeat the awake state and the sleep state. In this figure, the horizontal axis is the time axis.

  Signals denoted by reference signs S111 and S112 are beacon signals S111 and S112 transmitted by the radio base station apparatus AP. The beacon signals S111 and S112 include AP state information indicating the state of the radio base station device AP. For example, the AP state information includes information indicating the mode of the radio base station apparatus AP, and a period in which the radio base station apparatus AP is in an awake state (a period with a reference symbol A11; an activation time (awake period)). Or information indicating a sleep state period (a period indicated by reference sign A12; a sleep period). For example, the radio base station device AP enters a sleep state in which signal transmission / reception is stopped during the sleep period indicated by the AP state information. The beacon signal is a radio beacon and is a signal transmitted by the radio base station apparatus AP at a predetermined cycle.

  Signals denoted by reference signs R111 and R112 are beacon signals R111 and R112 received by the wireless terminal device STA, and are received signals of the beacon signals S111 and S112, respectively. After receiving the beacon signals R111 and R112, the wireless terminal device STA controls the state of the own device and signal transmission / reception based on the AP state information included in the beacon signals R111 and R112.

(First embodiment)
Hereinafter, a first embodiment of the present invention will be described in detail with reference to the drawings.
FIG. 2 is a schematic diagram showing the wireless communication system 1 according to the first embodiment of the present invention. In this figure, the radio communication system 1 includes a radio base station apparatus AP1 and radio terminal apparatuses STA11 and STA12 (each radio terminal apparatus is also referred to as STA1).

<About Configuration of Radio Base Station AP1>
FIG. 3 is a schematic block diagram showing the configuration of the radio base station apparatus AP1 according to this embodiment. In this figure, the radio base station apparatus AP1 includes a radio control apparatus a1 and a transmission / reception unit a11. The wireless control device a1 includes a STA management unit a101, a control unit a102, a state frame management unit a103, a transmission / reception control unit a104, a beacon transmission control unit a105, a buffer monitoring unit a107, and a transmission buffer a108. The radio base station apparatus AP1 has other general and known functions that the base station apparatus has.

The STA management unit a101 stores the STA state information input from the control unit a102. Here, the STA state information is information indicating the state of each wireless terminal device STA1.
The control unit a102 controls each unit of the wireless control device a1. For example, the control unit a102 receives the STA state information (for example, power management bit) transmitted from each wireless terminal device STA1 via the transmission / reception unit a11. The control unit a102 outputs the received STA state information to the STA management unit a101.
Also, for example, the control unit a102 determines (determines the mode (active mode or power save mode) of the radio base station apparatus AP1 based on the STA state information stored in the STA management unit a101. Mode is also referred to as AP mode). The control unit a102 stores AP mode information indicating the determined AP mode in the State frame management unit a103.

  The control unit a102 reads the AP mode information stored in the State frame management unit a103. In addition, when the read AP mode information indicates the power saving mode, the control unit a102 reads predetermined activation time information (AWAKE TIME) from the State frame management unit a103. The control unit a102 outputs the read AP mode information and activation time information to the beacon generation unit a106. The control unit a102 outputs the read AP mode information to the transmission / reception control unit a104.

The State frame management unit a103 sets the mode of the radio base station apparatus AP1 by storing the AP mode information and the activation time information input from the control unit a102. That is, the AP mode information stored in the State frame management unit a103 is the mode of the radio base station device AP1.
The transmission / reception control unit a104 controls the transmission / reception unit a11 based on the AP mode information input from the control unit a102. For example, in the power saving mode, the transmission / reception control unit a104 causes the transmission / reception unit a11 to temporarily stop transmission / reception (the stopped state is the sleep state). As a result, the transmission / reception control unit a104 suppresses the power consumed by the transmission / reception unit a11.
Also, the transmission / reception control unit a104 controls the transmission / reception unit a11 based on whether a signal is received from the wireless terminal device STA1.

The beacon transmission control unit a105 controls transmission of a beacon signal based on the AP mode set by the State frame management unit a103. For example, the beacon transmission control unit a105 outputs a beacon generation instruction that causes the beacon generation unit a106 to generate a beacon at a timing at which a beacon signal can be transmitted (for example, every cycle).
The beacon generation unit a106 generates a beacon signal based on the beacon generation instruction input from the beacon transmission control unit a105. Here, the beacon generation unit a106 generates a beacon signal including the AP mode information and the activation time information input from the control unit a102 as AP state information. The beacon generation unit a106 outputs the generated beacon signal to the transmission / reception unit a11.

The buffer monitoring unit a107 monitors the amount of transmission data stored in the transmission buffer a108. The buffer monitoring unit a107 outputs information indicating the monitoring result to the control unit a102.
The transmission buffer a108 temporarily accumulates transmission data to be transmitted to the wireless terminal device STA1.
The transmission / reception unit a11 transmits a beacon signal and a transmission data signal according to the control from the transmission / reception control unit a104. In addition, the transmission / reception unit a11 receives a signal from the wireless terminal device STA1 according to the control from the transmission / reception control unit a104. The transmission / reception unit a11 outputs the received data to the control unit a102.

<Configuration of Wireless Terminal Device STA1>
FIG. 4 is a schematic block diagram showing the configuration of the wireless terminal device STA1 according to this embodiment. In this figure, the wireless terminal device STA1 includes a wireless control device b1 and a transmission / reception unit b11. The wireless control device b1 includes a control unit b101, a memory b102, a transmission / reception control unit b103, a buffer monitoring unit b104, and a transmission buffer b105. The wireless terminal device STA1 has other general and known functions that the wireless terminal device has.

  The control unit b101 controls each unit of the wireless control device b1. Specifically, the control unit b101 stores the information transmitted from the radio base station device AP1 in the memory b102. For example, the control unit b101 extracts AP state information from the beacon signal, and stores the extracted AP state information in the memory b102. The control unit b101 determines the mode (active mode or power saving mode) of the wireless terminal device STA1 based on the AP state information stored in the memory b102. The control unit b101 stores STA state information indicating the determined mode in the memory b102. The control unit b101 outputs STA state information and AP state information indicating the determined mode to the transmission / reception control unit b103.

The transmission / reception control unit b103 controls the transmission / reception unit b11 based on the STA state information and the AP state information input from the control unit b101. For example, in the power saving mode, the transmission / reception control unit b103 regularly switches between an awake state in which power is completely supplied to the transmission / reception circuit and a sleep state (transmission / reception disabled state) that operates with the minimum necessary power. Transition.
The buffer monitoring unit b104 monitors the amount of transmission data stored in the transmission buffer b105. The buffer monitoring unit b104 outputs information indicating the monitoring result to the control unit b101.
The transmission buffer b105 temporarily stores transmission data to be transmitted to the wireless terminal device STA1.

  The transmission / reception unit b11 transmits transmission data according to the control from the transmission / reception control unit b104. For example, the transmission / reception unit b11 transmits the STA state information stored in the memory b102 to the radio base station apparatus AP1. Further, the transmission / reception unit b11 receives a signal from the radio base station apparatus AP1 in accordance with the control from the transmission / reception control unit b104. The transmission / reception unit b11 outputs the received data to the control unit b101.

<About beacon signal>
FIG. 5 is a schematic diagram illustrating an example of a frame configuration of a beacon signal according to the present embodiment. In this figure, a beacon signal denoted by reference numeral f1 includes a MAC (Media Access Control) header f11, a frame body, and an FCS (Frame Check Sequence: frame check sequence) f13. The frame body includes a State frame f12.
The State frame f12 includes a storage area for MODE (AP mode information) f121 and AWAKE TIME (activation time information) f122. For example, the value of “Power Save” (may be “0”) indicating the power saving mode or “Active” (may be “1”) indicating the active mode is set in MODE f121. Is done. Note that FCS f13 is a code added in the frame in order to detect and correct data errors in the communication protocol.

<Operation of Radio Base Station AP1>
FIG. 6 is a flowchart showing an example of the operation of the radio base station apparatus AP1 according to this embodiment.
(Step S101) The control unit a102 determines whether all the wireless terminal devices STA1 are in the power saving mode based on the STA state information stored in the STA management unit a101. When it is determined that at least one wireless terminal device STA1 is not in the power saving mode (No), the process proceeds to step S102. On the other hand, when it is determined that all the wireless terminal devices STA1 are in the power saving mode (Yes), the process proceeds to step S105.

(Step S102) The State frame management unit a103 sets the AP mode to “active mode”. Thereafter, the process proceeds to step S103.
(Step S103) The beacon generation unit a106 generates a beacon signal including AP mode information indicating the AP mode (“activity mode”) set in Step S102. The transmission / reception unit a11 transmits the beacon signal generated by the beacon generation unit a106 to the wireless terminal device STA1. Thereafter, the process proceeds to step S104.
(Step S104) The transmission / reception control unit a104 causes the transmission / reception unit a11 to perform transmission / reception while the transmission / reception unit a11 is activated. That is, the transmission / reception control unit a104 places the radio base station apparatus AP1 in an awake state.

(Step S105) The State frame management unit a103 sets the AP mode to “power saving mode”. Here, the State frame management unit a103 sets the activation time information. The activation time information represents the awake period of the radio base station device AP1. That is, the State frame management unit a103 sets a value in the State frame. Thereafter, the process proceeds to step S106.
(Step S106) The beacon generation unit a106 generates a beacon signal including the State frame set in step S105. The transmission / reception unit a11 transmits the beacon signal generated by the beacon generation unit a106 to the wireless terminal device STA1. Thereafter, the process proceeds to step S107.

(Step S107) The transmission / reception control unit a104 activates the transmission / reception unit a11 for a time (awake period) indicated by the activation time information, and causes the transmission / reception unit a11 to transmit and receive. Thereafter, the process proceeds to step S108.
(Step S108) The control unit a102 determines whether or not the transmission / reception unit a11 has received a signal from at least one wireless terminal device STA1. When it is determined that a signal has been received from at least one wireless terminal apparatus STA1 (Yes), the process proceeds to step 109. On the other hand, if it is determined that signals are not received from all the wireless terminal devices STA1 (No), the process proceeds to step S111.

(Step S109) The control unit a102 generates an ACK signal addressed to the wireless terminal device STA1 that has received the signal, and causes the transmission / reception unit a11 to transmit the generated ACK signal. Then, it progresses to step S110.
(Step S110) The transmission / reception control unit a104 keeps the transmission / reception unit a11 activated. That is, the transmission / reception control unit a104 places the radio base station apparatus AP1 in an awake state. In this case, the radio base station device AP1 maintains the awake state without referring to the activation time information. In other words, in this case, the radio base station apparatus AP1 does not refer to the activation time information, and thus it is not necessary to reset the activation time information.
(Step S111) The transmission / reception control unit a104 stops the transmission / reception unit a11 for a certain period (sleep period). That is, the transmission / reception control unit a104 sets the radio base station apparatus AP1 to the sleep state during the sleep period. The sleep period during which the transmission / reception unit a11 is stopped is determined in advance. The sleep period may be determined by, for example, the total time (period) of the time indicated by the activation time information (one awake period) and one sleep period, and the activation time information is subtracted from the period. It may be a value.

FIG. 7 is a flowchart showing an example of the operation of the STA management unit a101 according to the present embodiment.
(Step S201) When the wireless terminal device STA1 permits the connection to the wireless base station device AP1, the STA management unit a101 acquires the address (identification information) of the wireless terminal device STA1 to be connected. The STA management unit a101 stores STA state information in which the mode “activity mode” is associated with the acquired address. That is, the STA management unit a101 registers the address of the connected wireless terminal device STA1, and sets the mode of the wireless terminal device STA1 to “active mode”. Thereafter, the process proceeds to step S202.

(Step S202) When the control unit a102 acquires STA state information indicating “power saving mode” from the wireless terminal device STA1, the STA management unit a101 sets the mode corresponding to the address of the wireless terminal device STA1 to “power saving mode”. Update to That is, the STA management unit a101 sets the mode of the wireless terminal device STA1 that has transmitted the STA state information indicating the “power saving mode” to the “power saving mode”. After that, when the control unit a102 acquires the STA state information indicating the “activity mode” from the wireless terminal device STA1, the STA management unit a101 sets the mode corresponding to the address of the wireless terminal device STA1 to “activity mode”. Update.

<Operation of Wireless Terminal STA1>
FIG. 8 is a flowchart showing an example of the operation of the wireless terminal device STA1 according to the present embodiment.
(Step S301) The transmission / reception unit b11 receives the beacon signal transmitted from the radio base station device AP1. Note that the wireless terminal device STA1 enters an awake state when receiving a beacon signal and receives the beacon signal even when the wireless terminal device STA1 is in the power saving mode, for example. The transmission / reception unit b11 stores the value of the State frame of the received beacon signal in the memory b102 as AP state information. Thereafter, when transmission data to be transmitted to the radio base station apparatus AP1 is generated in the radio terminal apparatus STA1, the process proceeds to step S302.

(Step S302) The control unit b101 determines whether or not the mode of the radio base station device AP1 is the “power saving mode” based on the AP state information stored in the memory b102. When it determines with it being "power saving mode" (Yes), it progresses to step S303. On the other hand, if it is determined that the power saving mode is not set (No), the process proceeds to step S306.
(Step S303) The control unit b101 determines whether or not the radio base station device AP1 is in the sleep state based on the AP state information stored in the memory b102. Specifically, the control unit b101 determines that it is in the sleep state when the time indicated by the activation time information has elapsed, and is in the awake state when the time indicated by the activation time information has not elapsed. Is determined. When it is determined that the radio base station device AP1 is in the sleep state (Yes), the process proceeds to step S304. On the other hand, when it is determined that the radio base station device AP1 is not in the sleep state (No), the process proceeds to step S306.

(Step S304) The transmission / reception control unit a104 keeps the generated transmission data packet stored in the transmission buffer b105. That is, the transmission / reception control unit a104 suspends transmission of the transmission data packet. Thereafter, the process proceeds to step S305.
(Step S305) The transmission / reception unit b11 receives the beacon signal transmitted from the radio base station device AP1. The transmission / reception unit b11 stores the value of the State frame of the received beacon signal in the memory b102 as AP state information. At this time, the AP state information stored in the memory b102 indicates the “active mode” or the awake state in the “power saving mode”. Here, after transmitting the beacon signal, the radio base station device AP1 is activated for a time indicated by the activation time information (awake period), and then enters a sleep state (see steps S106 and 107 in FIG. 6). For this reason, immediately after the radio base station apparatus AP1 transmits a beacon signal, the radio base station apparatus AP1 is in an awake state.

(Step S306) The transmission / reception control unit a104 causes the transmission / reception unit b11 to transmit and receive signals. For example, the transmission / reception unit b11 transmits a transmission data signal stored in the transmission buffer b105. Thereafter, the process proceeds to step S307.
(Step S307) The control unit b101 determines whether the transmission / reception unit b11 has received an ACK signal from the radio base station apparatus AP1 with respect to the signal transmitted in step S306. If it is determined that an ACK signal has been received (Yes), the operation is terminated. On the other hand, if it is determined that the ACK signal has not been received (No), the process proceeds to step S308.
(Step S308) The controller b101 determines whether or not the back-off time has elapsed. The back-off time is a waiting time until the next transmission when a signal collision occurs. If it is determined that the back-off time has elapsed (Yes), the process proceeds to step S306. On the other hand, when it is determined that the back-off time has not elapsed (No), the process returns to step S308.

FIG. 9 is a schematic diagram illustrating an example of a relationship between intermittent communication and the state of the radio base station device AP1 according to the present embodiment. In this figure, the horizontal axis is the time axis.
FIG. 9A with reference numeral 9A shows an example when the radio base station apparatus AP1 is in the active mode. FIG. 9B with reference numeral 9B shows an example when the radio base station apparatus AP1 is in the power saving mode.

  In FIG. 9A, signals with reference numerals S211 and S212 are beacon signals S211 and S212 transmitted by the radio base station apparatus AP1. The beacon signal S211 includes AP state information indicating that the radio base station apparatus AP1 is in the “active mode”. In this case, when transmitting the beacon signal S211, the radio base station apparatus AP1 enters an awake state with a reference symbol A211 and thereafter transmits and receives signals.

  In FIG. 9B, signals with reference numerals S221 and S222 are beacon signals S221 and S222 transmitted by the radio base station apparatus AP1. The beacon signal S221 includes AP mode information indicating that the radio base station apparatus AP1 is in the “power saving mode”, and AP state information including activation time information. In this case, the radio base station device AP1 is in an awake state with the symbol A221 for the time indicated by the activation time information from the start of the cycle, and thereafter transmits and receives signals. After elapse of the time indicated by the activation time information, the radio base station apparatus AP1 enters a sleep state denoted by reference symbol A222, and stops transmission / reception of signals until the start of the next cycle.

FIG. 10 is a schematic diagram illustrating an example of a relationship between intermittent communication and the state of each device according to the present embodiment. In this figure, the horizontal axis is the time axis.
FIG. 10A with reference numeral 10A shows an example of the relationship between the intermittent communication and the state of the apparatus in the radio base station apparatus AP1. FIG. 10B denoted by reference numeral 10B shows an example of the relationship between the intermittent communication in the wireless terminal device STA1 and the state of the device.

  In FIG. 10A, signals with reference numerals S311, S312 and S315 are beacon signals S311, S312 and S315 transmitted by the radio base station apparatus AP1. The beacon signal S311 includes AP mode information indicating that the radio base station apparatus AP1 is in the “power saving mode” and AP state information including activation time information. In this case, the radio base station device AP1 is in an awake state with the reference A311 for the time indicated by the activation time information from the start of the cycle, and thereafter transmits and receives signals. After elapse of the time indicated by the activation time information, the radio base station device AP1 enters a sleep state denoted by reference numeral A312 and stops transmission / reception of signals until the start of the next cycle.

  In FIG. 10A, a signal denoted by reference numeral R313 is a signal received by the radio base station apparatus AP1, and is a received signal of the signal S324 denoted by reference numeral S324 in FIG. 10B. The signal denoted by reference numeral S314 is an ACK signal transmitted by the radio base station apparatus AP1. When the radio base station apparatus AP1 receives a signal from at least one radio terminal apparatus STA1 and transmits an ACK signal in the awake state, the radio base station apparatus AP1 continues the awake state denoted by reference numeral A313 in that cycle. Note that the radio base station device AP1 may continue the awake state only for a predetermined period (for example, in the next period). The predetermined cycle may be determined according to the amount of data received from the wireless terminal device STA1 and the number of wireless terminal devices STA1 that transmitted signals.

In FIG. 10B, signals denoted by reference numerals R321, R323, and R326 are beacon signals R321, R323, and R326 received by the wireless terminal device STA1, and are received signals of the beacon signals S311, S312, and S315, respectively.
Reference numeral H322 indicates transmission data H322 generated in the wireless terminal device STA1. Based on the AP state information included in the beacon signal R321, the wireless terminal device STA suspends transmission of the transmission data H322 signal. Specifically, the radio terminal apparatus STA suspends transmission of the signal of the transmission data H322 during the period in which the radio base station apparatus AP1 is in the sleep state.

In FIG. 10B, the signal denoted by reference numeral S324 is the signal S324 transmitted by the radio base station apparatus AP1. The signal S324 is a signal of the transmission data H322. Based on the AP state information included in the beacon signal R323, the wireless terminal device STA transmits the signal S324 during the period in which the wireless base station device AP1 is in the awake state.
In FIG. 10B, a signal denoted by reference numeral R325 is an ACK signal R325 received by the wireless terminal device STA1, and is a reception signal of the ACK signal S314.

  Thus, according to the present embodiment, in the radio base station apparatus AP1, the transmission / reception unit a11 transmits a beacon signal including AP state information indicating that the radio base station apparatus AP1 is in the power saving mode. That is, the wireless base station device AP1 includes a transmission unit (transmission / reception unit a11) that transmits a beacon signal including base station mode information (AP state information) indicating the state of the own device. The transmission / reception unit a11 enters a dormant state when the radio base station device AP1 is in the power saving mode. In the wireless terminal device STA1, the transmission / reception unit b11 receives a beacon signal including AP state information indicating the state of the wireless base station device AP1. The control unit b101 determines the state of the own device based on the AP state information. Thereby, in the radio | wireless communications system 1, power consumption can be suppressed.

  Further, according to the present embodiment, in the radio base station apparatus AP1, the STA management unit a101 manages STA state information indicating the state of the radio terminal apparatus STA1. When the STA state information indicates that the state of all the wireless terminal devices STA1 is the power saving mode, the control unit a102 determines the state of the wireless base station device AP1 to the power saving mode. Thereby, in the wireless communication system 1, when all the wireless terminal devices STA1 connected to the wireless base station device AP1 are in the power saving mode, the wireless base station device AP1 also shifts to the power saving mode, and the power consumption can be reduced. It becomes possible.

Further, in the radio base station apparatus AP1, the transmission / reception unit a11 enters a dormant state after entering a start state in which communication is possible at a predetermined start time when the radio base station apparatus AP1 is in the power saving mode. The beacon signal includes activation time information indicating the activation time. That is, in the radio base station apparatus AP1, the communication unit (transmission / reception unit a11) enters a dormant state after entering an activation state in which communication is possible at a predetermined activation time when the own device is in the power saving mode, and the beacon The signal includes activation time information indicating the activation time.
Thereby, when the radio base station apparatus AP1 shifts to the power saving mode, it is not necessary to transmit a sleep control packet, and power consumption can be reduced. Further, the wireless terminal device STA1 in the power saving mode can enter the awake state only when receiving a beacon signal. Further, since the radio terminal apparatus STA1 can transmit a signal in consideration of the state of the radio base station apparatus AP1, it is possible to prevent unnecessary signal transmission.

(Second Embodiment)
Hereinafter, a second embodiment of the present invention will be described in detail with reference to the drawings.
FIG. 11 is a schematic diagram showing a wireless communication system 2 according to the second embodiment of the present invention. In this figure, the radio communication system 2 includes a radio base station apparatus AP2 and radio terminal apparatuses STA21 and STA22 (each radio terminal apparatus is also referred to as STA2).
In the present embodiment, the radio base station device AP2 generates AP state information based on the presence / absence of the wireless terminal device STA2 connected to the radio base station device AP2, and transmits a beacon signal including the generated AP state information. .

<About Configuration of Radio Base Station Apparatus AP2>
FIG. 12 is a schematic block diagram showing the configuration of the radio base station device AP2 according to this embodiment. When the radio base station apparatus AP2 (FIG. 12) and the radio base station apparatus AP1 (FIG. 3) according to the first embodiment are compared, the control unit a202 of the radio control apparatus a2 is different. However, the functions of other configurations (STA management unit a101, State frame management unit a103, transmission / reception control unit a104, beacon transmission control unit a105, buffer monitoring unit a107, transmission buffer a108, and transmission / reception unit a11) are the first implementations. The form is the same. A description of the same functions as those in the first embodiment is omitted.

  The control unit a202 controls each unit of the wireless control device a2. For example, the control unit a202 outputs connection information indicating the connected wireless terminal device STA2 to the STA management unit a101. Here, the connected wireless terminal device STA2 refers to the wireless terminal device STA2 that can communicate with the wireless base station device AP2. Specifically, the wireless terminal device STA2 that is connected is a wireless terminal device STA2 that is permitted to connect to the wireless base station device AP2 based on a connection request from the wireless terminal device STA2, and is caused by a handover or a communication stoppage. The wireless terminal device STA2 has not stopped connection with the wireless base station device AP2. However, the present invention is not limited to this. For example, the connected wireless terminal device STA2 may be the connected wireless terminal device STA2 that is transmitting or receiving data, or may transmit data. Alternatively, it may be the wireless terminal device STA2 before the elapse of a predetermined time from reception.

For example, the control unit a202 determines the mode of the radio base station device AP2 based on the connection information stored in the STA management unit a101. The control unit a202 stores AP mode information indicating the determined AP mode in the State frame management unit a103.
The control unit a202 reads AP mode information stored in the State frame management unit a103. Further, when the read AP mode information indicates the power saving mode, the control unit a202 reads the activation time information (AWAKE TIME) from the State frame management unit a103. The control unit a202 outputs the read AP mode information and activation time information to the beacon generation unit a106. The control unit a202 outputs the read AP mode information to the transmission / reception control unit a104.

Since the wireless terminal device STA2 according to the present embodiment has the same configuration as the wireless terminal device STA1 (FIG. 4) according to the first embodiment, the description thereof is omitted. Here, for example, the transmission / reception control unit b103 causes the transmission / reception unit b11 to transmit a connection request addressed to the radio base station apparatus AP2. In addition, the transmission / reception control unit b103 is connected to the radio base station device AP2 when stopping the connection with the radio base station device AP2, such as when handing over to another radio base station device or when stopping communication. A stop request is transmitted to the transmission / reception unit b11.
An example of the frame configuration of the beacon signal according to the present embodiment is the same as that of the first embodiment (FIG. 5), and a description thereof will be omitted.

<Operation of Radio Base Station AP2>
FIG. 13 is a flowchart showing an example of the operation of the radio base station apparatus AP2 according to this embodiment. When the operation of the radio base station apparatus AP2 (FIG. 13) and the operation of the radio base station apparatus AP1 according to the first embodiment (FIG. 6) are compared, the processing in step S401 is different. However, the other processes are the same as those in the first embodiment, and thus description thereof is omitted.

(Step S401) The control unit a202 determines whether there is a wireless terminal device STA2 connected to the wireless base station device AP2 based on the connection information stored in the STA management unit a101. When it is determined that there is no wireless terminal device STA2 connected to the wireless base station device AP2 (No), the process proceeds to step S102. On the other hand, when it is determined that there is a wireless terminal device STA2 connected to the wireless base station device AP2 (Yes), the process proceeds to step S105.

  An example of the operation of the STA management unit a101 according to the present embodiment is the same as that of the first embodiment (FIG. 7), and a description thereof will be omitted. When the control unit a202 receives a connection stop request from the wireless terminal device STA2, or when the wireless base station device AP2 and the wireless terminal device STA2 do not transmit and receive during a predetermined period, the wireless terminal device STA2 The address (identification information) is deleted from the connection information.

  An example of the operation of the wireless terminal device STA2 according to the present embodiment is the same as the operation of the wireless terminal device STA1 (FIG. 8), and a description thereof will be omitted. An example of the relationship between the intermittent communication according to the present embodiment and the state of the radio base station device AP2 is the same as that of the first embodiment (FIG. 9), and thus the description thereof is omitted. An example of the relationship between the intermittent communication according to the present embodiment and the state of each device is the same as that of the first embodiment (FIG. 10), and thus the description thereof is omitted.

As described above, according to the present embodiment, the STA management unit a101 manages STA state information indicating the connection status of the wireless terminal device STA2. When the STA state information indicates that the wireless terminal device STA2 is not connected to the wireless base station device AP2, the control unit a202 determines the state of the wireless terminal device STA2 to the power saving mode. In this case, the transmission / reception unit a11 transmits a beacon signal including AP state information indicating that the radio base station device AP2 is in the power saving mode. That is, the radio base station device AP2 includes a terminal management unit (STA management unit a101) that manages terminal state information (STA state information) indicating a connection status of the wireless terminal device STA2, and the terminal state information is transmitted to the own device. And a control unit that determines the state of the own apparatus to the power saving mode when indicating that the STA2 is not connected.
Thereby, in the radio | wireless communications system 2, when radio | wireless terminal apparatus STA2 connected to radio base station apparatus AP2 is zero, radio base station apparatus AP2 transfers to a power saving mode, and it becomes possible to reduce power consumption. Further, when the radio base station device AP2 shifts to the power saving mode, it is not necessary to transmit a sleep control packet, and power consumption can be reduced. Further, the wireless terminal device STA2 in the power saving mode can enter an awake state only when receiving a beacon signal. Further, since the radio terminal apparatus STA1 can transmit a signal in consideration of the state of the radio base station apparatus AP2, it is possible to prevent unnecessary signal transmission.

(Third embodiment)
Hereinafter, the third embodiment of the present invention will be described in detail with reference to the drawings.
FIG. 14 is a schematic diagram showing a wireless communication system 3 according to the third embodiment of the present invention. In this figure, the radio communication system 3 includes a radio base station apparatus AP3 and radio terminal apparatuses STA31 and STA32 (each radio terminal apparatus is also referred to as STA3).
In the present embodiment, the radio base station device AP3 generates AP state information based on the capacity of the transmission buffer, and transmits a beacon signal including the generated AP state information.

<Configuration of the radio base station apparatus AP3>
FIG. 15 is a schematic block diagram showing the configuration of the radio base station device AP3 according to this embodiment. When the radio base station apparatus AP3 (FIG. 15) and the radio base station apparatus AP1 (FIG. 3) according to the first embodiment are compared, the control unit a302 of the radio control apparatus a3 is different. However, the functions of other configurations (STA management unit a101, State frame management unit a103, transmission / reception control unit a104, beacon transmission control unit a105, buffer monitoring unit a107, transmission buffer a108, and transmission / reception unit a11) are the first implementations. The form is the same. A description of the same functions as those in the first embodiment is omitted.

The control unit a302 controls each unit of the wireless control device a3. For example, the control unit a302 receives the STA state information transmitted from the wireless terminal device STA3 via the transmission / reception unit a11. The control unit a102 outputs the received STA state information to the STA management unit a101.
Further, for example, the control unit a302 determines the mode of the radio base station device AP3 based on the monitoring result indicated by the information input from the buffer monitoring unit a107. The control unit a302 stores AP mode information indicating the determined AP mode in the State frame management unit a103.

  The control unit a302 reads AP mode information stored in the State frame management unit a103. Further, when the read AP mode information indicates the power saving mode, the control unit a302 reads activation time information (AWAKE TIME) from the State frame management unit a103. The control unit a302 outputs the read AP mode information and activation time information to the beacon generation unit a106. The control unit a302 outputs the read AP mode information to the transmission / reception control unit a104.

Since the wireless terminal device STA3 according to the present embodiment has the same configuration as the wireless terminal device STA1 (FIG. 4) according to the first embodiment, a description thereof will be omitted. Here, when the transmission / reception control unit b103 requests the radio base station apparatus AP3 to transmit transmission data, the transmission / reception unit b11 causes the transmission / reception unit b11 to transmit PS (Power Save) -Poll. Note that PS-Poll is a transmission request for transmission data, which is transmitted by the wireless terminal device STA3.
An example of the frame configuration of the beacon signal according to the present embodiment is the same as that of the first embodiment (FIG. 5), and a description thereof will be omitted.

<Operation of Radio Base Station AP3>
FIG. 16 is a flowchart showing an example of the operation of the radio base station device AP3 according to this embodiment. When the operation of the radio base station device AP3 (FIG. 13) and the operation of the radio base station device AP1 according to the first embodiment are compared, the processes in steps S501 and S511 to S518 are different. However, since other processes are the same as those in the first embodiment, description of the same processes as those in the first embodiment is omitted. Note that after the processing in step S109, the process proceeds to step S518.

(Step S501) The control unit a302 determines whether or not the transmission buffer a108 is empty based on the monitoring result indicated by the information input from the buffer monitoring unit a107. When it is determined that the transmission buffer a108 is empty (Yes), the process proceeds to step S105. On the other hand, if it is determined that the transmission buffer a108 is not empty (No), the process proceeds to step S102.
(Step S511) Based on the STA state information stored in the STA management unit a101, the control unit a302 determines whether or not the wireless terminal device STA3 that is the transmission destination of the transmission data is in the power saving mode. If it is determined that the destination wireless terminal device STA3 is not in the power saving mode (No), the process proceeds to step S512. On the other hand, when it is determined that the transmission destination wireless terminal device STA3 is in the power saving mode (Yes), the process proceeds to step S514.

(Step S512) The control unit a302 transmits a signal of transmission data to the wireless terminal device STA3 that is determined not to be in the power saving mode in step S511. Thereafter, the process proceeds to step S513.
(Step S513) The beacon generation unit a106 generates a beacon signal including AP mode information indicating the AP mode (“activity mode”) set in Step S102. The transmission / reception unit a11 transmits the beacon signal generated by the beacon generation unit a106 to the wireless terminal device STA3. Thereafter, the process proceeds to step S518.

(Step S514) The control unit a302 causes the transmission buffer a108 to accumulate transmission data to be transmitted to the wireless terminal device STA3 that has been determined to be in the power saving mode in step S511. Thereafter, the process proceeds to step S515.
(Step S515) The beacon generation unit a106 generates a beacon signal including AP mode information indicating the AP mode (“activity mode”) set in step S102. Note that the beacon signal includes storage information indicating that transmission data is stored for each destination (wireless terminal apparatus STA3) of the transmission data stored in step S514. The transmission / reception unit a11 transmits the beacon signal generated by the beacon generation unit a106 to the wireless terminal device STA3. Thereafter, the process proceeds to step S516.

(Step S516) The control unit a302 determines whether or not PS-Poll has been received from the wireless terminal device STA3 that has been determined to be in the power saving mode in step S511. When it is determined that PS-Poll has been received (Yes), the process proceeds to step S517. On the other hand, when it determines with not receiving PS-Poll (No), it returns to step S515.
(Step S517) The control unit a302 transmits the transmission data signal accumulated in step S514 and the transmission data signal generated thereafter to the wireless terminal apparatus STA3 that has transmitted the PS-Poll received in step S516. Thereafter, the process proceeds to step S518.
(Step S518) The transmission / reception control unit a104 keeps the transmission / reception unit a11 activated. That is, the transmission / reception control unit a104 places the radio base station device AP3 in an awake state.

  An example of the operation of the STA management unit a101 according to the present embodiment is the same as that of the first embodiment (FIG. 7), and a description thereof will be omitted. An example of the operation of the wireless terminal device STA3 according to the present embodiment is the same as that of the wireless terminal device STA1 (FIG. 8), and a description thereof will be omitted.

  FIG. 17 is a flowchart illustrating an example of another operation of the wireless terminal device STA3 according to the present embodiment. This operation shows an example of the operation when the wireless terminal device STA3 is in the power saving mode. Note that the wireless terminal device STA1 according to the first embodiment and the wireless terminal device STA2 according to the second embodiment also perform the operation illustrated in FIG. 17 as an example in the power saving mode.

(Step S601) When the STA state information indicating the power saving mode is input from the control unit b101, the transmission / reception control unit b103 causes the transmission / reception unit b11 to transmit the STA state information. Here, the transmission / reception unit b11 transmits STA state information indicating the power saving mode to the radio base station apparatus AP3 using, for example, a power management bit. That is, the radio terminal apparatus STA3 notifies the radio base station apparatus AP3 of the mode change (change from the activity mode to the power saving mode). Thereafter, the process proceeds to step S602.
(Step S602) The control unit b101 stores STA state information indicating the power saving mode in the memory b102. Thereby, the radio base station apparatus AP3 shifts to the power saving mode. Thereafter, the process proceeds to step S603.

(Step S603) The control unit b101 receives the beacon signal transmitted by the wireless base station device AP3. Based on the accumulation information included in the beacon signal, the control unit b101 determines whether or not transmission data addressed to itself is accumulated in the radio base station apparatus AP3. When it is determined that transmission data addressed to the own apparatus is accumulated (Yes), the process proceeds to step S605. On the other hand, when it is determined that the transmission data addressed to the own apparatus is not accumulated (No), the process returns to step S603.
(Step S605) The transmission / reception control unit b103 causes the transmission / reception unit b11 to transmit PS-Poll addressed to the radio base station device AP3. Thereafter, the process proceeds to step S606.
(Step S606) The transmission / reception unit b11 receives a transmission data signal transmitted from the radio base station apparatus AP3. The control unit b101 acquires transmission data of the received signal.

  An example of the relationship between the intermittent communication according to the present embodiment and the state of the radio base station device AP3 is the same as that of the first embodiment (FIG. 9), and thus the description thereof is omitted. An example of the relationship between the intermittent communication according to the present embodiment and the state of each device is the same as that of the first embodiment (FIG. 10), and thus the description thereof is omitted.

Thus, according to the present embodiment, in the radio base station apparatus AP3, the transmission buffer a108 accumulates data addressed to the radio terminal apparatus STA3. When the transmission buffer a108 does not accumulate data, the control unit a302 determines the state of the radio base station device AP3 to the power saving mode. In this case, the transmission / reception unit a11 transmits the radio base station device AP3 in the power saving mode. A beacon signal including AP state information indicating the presence is transmitted. That is, the radio base station device AP3 determines the state of its own device as the power saving mode when the data of the STA3 addressed to the radio terminal device is accumulated and the transmission buffer does not accumulate the data. A control unit (control unit a302).
Thereby, in the wireless communication system 3, when the transmission buffer a108 does not accumulate data and the wireless base station device AP3 does not need to perform communication, the wireless base station device AP3 shifts to the power saving mode, and the power consumption Can be reduced. Further, when the radio base station apparatus AP3 shifts to the power saving mode, it is not necessary to transmit a sleep control packet, and power consumption can be reduced. Further, the wireless terminal device STA3 in the power saving mode can enter an awake state only when receiving a beacon signal. Further, since the radio terminal apparatus STA1 can transmit a signal in consideration of the state of the radio base station apparatus AP3, it is possible to prevent useless signal transmission.

  In each of the above embodiments, the radio base station devices AP1, AP2, and AP3 may include the State frame only in the DTIM beacon signal. Alternatively, the radio base station apparatuses AP1, AP2, and AP3 may include a State frame in all beacons. Further, in each of the above embodiments, the radio base station apparatuses AP1, AP2, and AP3 have described the case where the State frame is included in the frame body of the beacon signal. However, the present invention is not limited to this, and other fields are set. May be. The radio base station apparatuses AP1, AP2, and AP3 may include a State frame in a conventional field (for example, include AP mode information or activation time information in the “power management” area of the frame control of the MAC header). May be)

Further, in each of the above embodiments, the radio base station apparatuses AP1, AP2, and AP3 have described the case where both the AP mode information and the activation time information are set in the State frame. However, the present invention is not limited to this, and either May be set. In addition, the radio base station devices AP1, AP2, and AP3 set the AP mode information and the activation time information in the State frame, but other frames may be set (for example, the radio base station devices AP1, AP2, and AP3 "Active STA" may be set to notify the wireless terminal devices STA1, STA2, and STA3 of the number of wireless terminal devices STA1, STA2, and STA3 that are in an active state connected to the wireless terminal device STA3).
In each of the above embodiments, the radio base station devices AP1, AP2, and AP3 may continue the awake state for a predetermined time in the power saving mode without setting the activation time information. In addition, the wireless base station devices AP1, AP2, and AP3 notify the wireless terminal devices STA1, STA2, and STA3 that the wireless base station devices AP1, AP2, and AP3 are in the power saving mode. A WAN or the like may be used.
Moreover, you may normalize an example of the operation | movement shown in drawing in each said embodiment.

In addition, you may make it implement | achieve a part of radio | wireless base station apparatus AP1, AP2, AP3, radio | wireless terminal apparatus STA1, STA2, and STA3 in embodiment mentioned above with a computer. In that case, the program for realizing the control function may be recorded on a computer-readable recording medium, and the program recorded on the recording medium may be read by a computer system and executed. The “computer system” here is a computer system built in the radio base station apparatuses AP1, AP2, AP3, radio terminal apparatuses STA1, STA2, and STA3, and includes hardware such as an OS and peripheral devices. Shall be. The “computer-readable recording medium” refers to a storage device such as a flexible medium, a magneto-optical disk, a portable medium such as a ROM and a CD-ROM, and a hard disk incorporated in a computer system. Furthermore, the “computer-readable recording medium” is a medium that dynamically holds a program for a short time, such as a communication line when transmitting a program via a network such as the Internet or a communication line such as a telephone line, In such a case, a volatile memory inside a computer system serving as a server or a client may be included and a program that holds a program for a certain period of time. The program may be a program for realizing a part of the functions described above, and may be a program capable of realizing the functions described above in combination with a program already recorded in a computer system.
Moreover, you may implement | achieve part or all of radio | wireless base station apparatus AP1, AP2, AP3 and radio | wireless terminal apparatus STA1, STA2, STA3 in embodiment mentioned above as integrated circuits, such as LSI (Large Scale Integration). Each functional block of the radio base station apparatuses AP1, AP2, AP3 and radio terminal apparatuses STA1, STA2, and STA3 may be individually made into a processor, or a part or all of them may be integrated into a processor. Further, the method of circuit integration is not limited to LSI, and may be realized by a dedicated circuit or a general-purpose processor. Further, in the case where an integrated circuit technology that replaces LSI appears due to progress in semiconductor technology, an integrated circuit based on the technology may be used.

  As described above, the embodiment of the present invention has been described in detail with reference to the drawings. However, the specific configuration is not limited to the above, and various design changes and the like can be made without departing from the scope of the present invention. It is possible to

  AP1, AP2, AP3 ... wireless base station device, a1, a2, a3 ... wireless control device, a11 ... transmission / reception unit (transmission unit, communication unit), a101 ... STA management unit, a102, a202 , A302 ... control unit, a103 ... State frame management unit, a104 ... transmission / reception control unit, a105 ... beacon transmission control unit, a107 ... buffer monitoring unit, a108 ... transmission buffer, STA11 , STA12, STA1, STA21, STA22, STA2, STA31, STA32, STA3... Wireless terminal device, b1... Line control device, b11. Memory, b103 ... transmission / reception control unit, b104 ... buffer monitoring unit, b105 ... transmission buffer

Claims (5)

A communication unit that enters a dormant state when the device itself is in a power saving mode; and
A transmission unit for transmitting a beacon signal including base station mode information indicating the state of the own device;
With
The radio base station apparatus, wherein the base station mode information is information indicating that the own apparatus is in a power saving mode. A terminal management unit that manages terminal state information indicating the state of the wireless terminal device;
When the terminal state information indicates that the state of all wireless terminal devices is the power saving mode, a control unit that determines the state of the own device to the power saving mode;
The radio base station apparatus according to claim 1, comprising: A receiving unit for receiving a beacon signal including base station mode information indicating a state of the radio base station device;
Based on the base station mode information, a control unit that determines the state of the device itself;
A wireless terminal device comprising: The wireless terminal device receives a beacon signal including base station mode information indicating the state of the wireless base station device;
A process in which the wireless terminal device determines its own state based on the base station mode information;
A communication control method characterized by comprising: In the computer of the wireless terminal device,
Means for receiving a beacon signal including base station mode information indicating a state of the radio base station device;
Means for determining a state of the own apparatus based on the base station mode information;
Communication control program to execute.

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