JP2015076764A - Communication device, control method, and program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To maintain connection with an opposite device in a communication device executing power saving control.SOLUTION: A communication device is able to connect with an opposite device by using a first communication function to directly connect with the opposite device, and a second communication function to connect with the opposite device via another device and to perform at least part of communication for establishing connection by the first communication function. The communication device determines whether connection is interrupted in a state of the connection with the opposite device being established by the second communication function, and finishes power saving control if it is determined that the connection has been interrupted during execution of the power saving control.

Description

  The present invention relates to a communication apparatus capable of power saving control.

  In recent years, communication apparatuses equipped with a wireless LAN function are increasing. Such a communication apparatus can be connected to a wireless LAN access point (AP) by the wireless LAN function to connect to the Internet or communicate with a communication partner apparatus. Here, when the communication device and the partner device are located close to each other, these devices can communicate with each other via the AP, and also directly communicate with each other without the AP. You can also.

  Non-Patent Document 1 describes a wireless LAN technology called Tunneled Direct Link Setup (hereinafter referred to as TDLS) that allows a communication device connected to an AP to communicate directly. In this technique, control data for TDLS setting is transmitted / received via the AP, and direct communication is performed between the communication device and the counterpart device.

  Patent Document 1 discloses control for reducing power consumption of terminals participating in TDLS. With reference to FIG. 12, the flow of processing for performing communication when a communication device participating in TDLS is executing power saving control in Patent Document 1 will be described. In this process, it is assumed that the first communication device executes power saving control. The first communication device notifies the access point of the transition to the power saving state and notifies the second communication device using TDLS direct communication. Thereafter, the first communication device stops the wireless circuit until the next time when the access point transmits the notification signal, and enters the power saving state. The second communication device cancels the power saving state of the first communication device by sending Peer Traffic Indication to the first communication device via the access point when the first communication device of the data transmission destination is in the power saving state. Let The second communication device receives the Peer Traffic Response from the first communication device, confirms that the power saving state of the first communication device has been released, and then transmits data by direct communication. When receiving the last transmission data, the first communication device notifies the access point and the second communication device again of starting the power saving control.

Special table 2010-521117

IEEE Std 802.11z (TM) -2010: IEEE Standard for Information Technology-Telecommunications and information exchange between systems-Local and metropolitan area networks-Specific requirements Part 11: Wireless LAN Medium Access Control (MAC) and Physical Layer (PHY) specifications Amenment 7: Extensions to Direct-Link Setup (DLS)

  In this power saving control, when the connection between the partner device and the AP or the connection between the communication device and the AP is interrupted, the communication device receives Peer Traffic Indication from the partner device via the AP. I can't. Even if the partner device sends Peer Traffic Indication using direct communication, the communication device itself may be in a power saving state and may not be able to receive it. Therefore, there is a problem that even if the communication device and the partner device are at a distance that allows direct communication with each other, data transmission from the partner device may not be started.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a technique for maintaining a connection with a counterpart device in a communication device that is executing power saving control.

  In order to achieve the above object, a communication device according to the present invention has a first communication function that directly connects to a counterpart device, and connects to the counterpart device via another device, and establishes a connection using the first communication function. A communication device having communication means connectable to the counterpart device using a second communication function for executing at least a part of communication for the communication device, wherein the communication device is connected to the counterpart device by the second communication function. In the state where the connection is established, the determination means for determining whether or not the connection has been interrupted, and the control to end the power saving control when it is determined that the connection has been interrupted while executing the power saving control. Control means.

  ADVANTAGE OF THE INVENTION According to this invention, the communication apparatus which is performing power saving control can maintain a connection with the other party apparatus.

The figure which shows the network structural example. The block diagram which shows the hardware structural example of a terminal. The block diagram which shows the function structural example of a terminal. The flowchart which shows the flow of the process example which a terminal performs during power saving control. The sequence diagram which shows the operation example of a communication system. The block diagram which shows another example of the function structure of a terminal. The flowchart which shows the flow of another example of a process which a terminal performs during power saving control. The sequence diagram which shows another operation example of a communication system. The block diagram which shows another example of the function structure of a terminal. The flowchart which shows the flow of another example of a process which a terminal performs during power saving control. The sequence diagram which shows another operation example of a communication system. The sequence diagram which shows the flow of the process for communicating when the communication apparatus which has participated in the conventional TDLS is performing power saving control.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the following, an example using a wireless LAN system compliant with the IEEE802.11 series will be described, but the communication form is not necessarily limited to a wireless LAN compliant with IEEE802.11.

<< Embodiment 1 >>
(Configuration of communication system)
FIG. 1 shows a wireless communication system according to this embodiment. This wireless communication system includes a terminal 101, a terminal 102, and an access point (hereinafter referred to as AP) 103 as wireless communication devices. Here, the AP 103 only needs to be a communication device having a function as a general access point (or base station), and thus detailed description thereof will be omitted below.

  Each of the terminal 101 and the terminal 102 has a first communication function that can be connected by direct communication, and a second communication function that can be connected via the AP 103. The terminal 101 executes a direct link setting process, for example, according to a user instruction, and sets up a direct communication path with the terminal 102 connected to the AP 103. In the following, it is assumed that the terminal 102 is executing power saving control. Further, the terminal 101 is located farther from the AP 103 than the terminal 102, and communication with the AP 103 is likely to be interrupted.

(Terminal configuration)
FIG. 2 is a block diagram illustrating a hardware configuration example of the terminal 101 and the terminal 102 according to the present embodiment. The terminal 201 includes, for example, a control unit 202, a storage unit 203, a wireless unit 204, a display unit 205, an antenna control unit 206, an antenna 207, and an input unit 208.

  The control unit 202 is, for example, a computer such as a CPU or MPU, and controls the entire apparatus by executing a control program stored in the storage unit 203. The control unit 202 also executes control of a communication parameter automatic setting system performed with other devices. The storage unit 203 stores a computer program for control executed by the control unit 202 and various types of information such as communication parameters. Various operations to be described later are performed, for example, when the control unit 202 executes a control program stored in the storage unit 203. Further, hardware for executing at least a part of various operations described below may be separately prepared. The storage unit 203 may be configured by a memory such as a ROM or a RAM, or a flexible disk, a hard disk, an optical disk, a magneto-optical disk, a CD-ROM, a CD-R, a magnetic tape, a nonvolatile memory card, a DVD, or the like.

  The wireless unit 204 is a functional unit for performing wireless communication. The display unit 205 has a function capable of outputting visually recognizable information such as an LCD or LED, or outputting sound such as a speaker, and performs various displays. The antenna control unit 206 controls the antenna 207 to perform at least one of transmission and reception of a radio signal. The input unit 208 receives various inputs from the user.

  Note that the wireless unit 204, the antenna control unit 206, and the like include a first communication function that provides a direct connection with the counterpart device as described above, and a second communication function that provides a connection via an AP, or will be described later. An ad hoc communication function, a simple AP function, and the like can be switched and executed. However, the present invention is not limited to this, and the terminal 201 may have different hardware for each of these various communication functions. Further, the terminal 201 may have one hardware for a group including a plurality of communication functions, and may have another hardware for a communication function outside the group. Therefore, the terminal 201 can apply the functions described below to any combination of communication functions.

  FIG. 3 is a block diagram illustrating a configuration example of functions of the terminal 101 and the terminal 102. In addition, although the function for mainly performing a direct link process is shown by FIG. 3, the terminal may have a function as a general communication apparatus other than this. The terminal 301 includes, for example, a direct link communication function 302, an infrastructure communication function 303, a packet reception unit 304, and a packet transmission unit 305. The direct link communication function 302 controls the direct communication function between terminals. The infrastructure communication function 303 performs connection control with the AP. The terminal establishes a direct connection with the communication partner device by the direct link communication function 302 or establishes a connection through the AP by the infrastructure communication function 303 to perform communication.

  The packet transmission unit 305 transmits packets related to various communications. Data packet transmission is performed by the packet transmission unit 305. The packet transmission unit 305 may be a general wireless signal transmission unit that transmits wireless signals other than packets. The packet receiving unit 304 receives packets related to various communications. Reception of the beacon (notification signal) is performed by the packet receiving unit 304. Further, infrastructure and direct link data packets are also received by the packet receiver 304. The packet receiving unit 304 may be a general wireless signal receiving unit that receives wireless signals other than packets.

  The direct link communication function 302 includes, for example, a direct link setting unit 306, a direct link power saving control unit 307, and a direct link data transmission / reception unit 308. The direct link setting unit 306 performs direct link setting processing.

  The direct link power saving control unit 307 performs power saving control for direct link connection. For example, the direct link power saving control unit 307 executes the power saving function during a period in which transmission / reception is not performed. When the direct link power saving control unit 307 starts power saving control, power saving control by an infrastructure power saving control unit 311 described later is also started. On the other hand, when a TDLS Peer Traffic Indication described later is received, the power saving control by the infrastructure power saving control unit 311 is invalidated until a series of data transmission from the opposite terminal is completed.

  The direct link data transmission / reception unit 308 performs data transmission / reception on the direct link. The direct link data transmission / reception unit 308 transmits or receives a TDLS Peer Traffic Response (described later) in addition to the data packet on the direct link.

  The infrastructure communication function 303 includes, for example, an infrastructure network control unit 309, an infrastructure power saving control unit 311, and an infrastructure data transmission / reception unit 312. The infrastructure communication function 303 further includes an infrastructure communication interruption detection unit 310 and an infrastructure survival confirmation unit 313. The infrastructure network control unit 309 controls connection to the AP. The connection to the AP and the disconnection processing are performed by the infrastructure network control unit 309. The infrastructure communication disruption detection unit 310 detects that the connection between the terminal and the AP has been disrupted.

  The infrastructure power saving control unit 311 performs power saving control on the infrastructure network. In the infrastructure power saving control unit 311, for example, after receiving a beacon from the AP, the power supply to the radio unit 204 and the antenna control unit 206 is limited or cut off during a period in which no signal is transmitted / received. Reduce power consumption. In addition, the infrastructure power saving control unit 311 resumes power supply to the radio unit 204 and the antenna control unit 206 when the beacon reception time from the next AP approaches, and prepares for the reception of the beacon. Take control.

  The infrastructure data transmission / reception unit 312 performs data transmission / reception via the AP. Transmission of the direct link start message and transmission / reception of a TDLS Peer Traffic Indication described later are performed using the infrastructure data transmission / reception unit 312.

  The infrastructure survival confirmation unit 313 determines whether the partner device has left the infrastructure network, that is, whether the connection between the partner device and the AP has not been interrupted. For example, the infrastructure existence confirmation unit 313 transmits a predetermined signal (ICMP Echo Request (Ping)) to the counterpart apparatus via the access point, and makes a survival confirmation request to the counterpart apparatus. Then, the infrastructure existence confirmation unit 313 can determine that the connection between the partner apparatus and the AP is not interrupted by receiving ICMP Echo Reply from the partner apparatus. Further, when the predetermined signal (ICMP Echo Request) is received from the counterpart device, a response signal (ICMP Echo Reply) is transmitted to the counterpart device via the access point, thereby responding to the survival confirmation request.

(Device operation)
FIG. 4 is a flowchart showing a flow of processing executed by the terminal 101 or the terminal 102 during power saving control. Each process of FIG. 4 is performed, for example, when the control unit 202 reads and executes a computer program stored in the storage unit 203. In the following, it is assumed that the terminal 101 is executing power saving control.

  The terminal 101 that is executing the power saving control waits for a beacon from the AP 103. (S401). Note that the beacon is transmitted at a predetermined cycle, for example, and the terminal 101, for example, except for the period for receiving the beacon or the period for transmitting or receiving the above-mentioned survival confirmation signal, for example, the wireless unit 204 and Power saving control is performed by restricting power supply to the antenna control unit 206.

  Then, the terminal 101 determines whether there is received data addressed to the terminal 101 based on the Traffic Indication Map (TIM) information included in the beacon received from the AP 103 (S402). If the terminal 101 determines that there is data addressed to the terminal 101 (YES in S402), the terminal 101 requests the AP 103 to transmit received data (S403). On the other hand, if the terminal 101 determines that there is no data addressed to the terminal 101 (NO in S402), the process proceeds to S411.

  When the terminal 101 receives the data packet in response to the request in S403, the terminal 101 determines whether or not the data packet is a TDLS Peer Traffic Indication from the terminal 102 (S404). If the received data packet is not TDLS Peer Traffic Indication (NO in S404), the terminal 101 advances the process to S411.

  When the received data packet is TDLS Peer Traffic Indication (YES in S404), the direct link power saving control unit 307 of the terminal 101 invalidates the power saving control and ends (S405). Then, a TDLS Peer Traffic Response is transmitted by direct communication with the terminal 102 (S406). Then, the terminal 101 waits for data from the terminal 102 (S407), and determines from the packet received in S407 whether the data transmission of the terminal 102 has been completed (S408). If the terminal 101 determines that it is not the last data (NO in S408), it waits for the next packet (S407). On the other hand, when determining that the data is the last data (YES in S408), the direct link power saving control unit 307 of the terminal 101 validates and restarts the power saving control (S410). Further, the direct link power saving control unit 307 of the terminal 101 notifies the terminal 102 that the power saving control has been validated by direct communication (S410). Thereafter, the terminal 101 returns the process to S401.

  In S411, the infrastructure existence confirmation unit 313 of the terminal 101 determines whether to execute the existence confirmation request based on, for example, the elapsed time from the execution of the previous existence confirmation request. For example, when it is determined that the predetermined time has not elapsed and the survival confirmation request is not executed (NO in S411), the terminal 101 moves the process to S414. On the other hand, for example, if it is determined that a survival confirmation request is to be executed after a predetermined time has elapsed (YES in S411), the infrastructure survival confirmation unit 313 of the terminal 101 sends a survival confirmation request to the terminal 102 via the infrastructure data transmission / reception unit 312. Transmit (S412). The survival confirmation request is, for example, ICMP Echo Request.

  After transmitting the survival confirmation request, the terminal 101 waits for a response signal (ICMP Echo Reply) from the terminal 102 (S413). When the terminal 101 receives ICMP Echo Reply within a predetermined time (YES in S413), the infrastructure power saving control unit 311 makes a transition to the power saving state again (S414). Then, in a period for receiving the next beacon (for example, a predetermined period immediately before the reception time), the power saving state is canceled (S415), and the beacon is waited again.

  On the other hand, if the response signal (ICMP echo reply) is not received within the predetermined time in S413, the terminal 101 determines that the connection between the terminal 102 and the AP 103 has been lost, and disables the power saving control. And end (S416). In addition, the direct link power saving control unit 307 of the terminal 101 notifies the terminal 102 of the completion of power saving control by transmitting a Peer Traffic Response by direct communication (S417). Note that the terminal 101 has not received the TDLS Peer Traffic Indication, but transmits a Peer Traffic Response to indicate that it has returned from the power saving control.

  In this way, in a state where the connection via the AP 103 is established between the terminal 101 and the terminal 102, the terminal 101 confirms that the connection between the AP 103 and the terminal 101 is not interrupted by the reception of the beacon. Can be confirmed. The terminal 101 transmits a predetermined signal to the terminal 102 via the AP 103 in a situation where the beacon can be received (that is, a state where the connection between the terminal 101 and the AP 103 is not interrupted). Determine if a response has been received. Thereby, it is possible to determine whether the connection between the AP 103 and the terminal 102 has been interrupted. It should be noted that the power saving function can be realized by not supplying power to the communication function outside the period in which the signal transmission or reception associated with these determinations is performed.

  As a result, even when the power saving function is being executed, it is possible to determine whether or not the connection with the partner apparatus via the AP 103 has been interrupted, and the power saving control is terminated in response to the disconnection. By doing so, the connection with the other apparatus by direct communication can be maintained. In addition, when both the terminal 101 and the terminal 102 are under power saving control and the connection between one terminal and the AP 103 is interrupted, the one terminal does not receive a beacon for a predetermined period, thereby disconnecting the connection. The power saving control can be completed after confirmation. In addition, the other terminal did not receive a survival confirmation request from the partner device because it did not respond even though it transmitted a survival confirmation request, or a predetermined time had elapsed. Thus, the disconnection can be confirmed and the power saving control can be terminated.

(System operation)
FIG. 5 shows a system in which communication between the terminal 102 and the AP 103 is interrupted when a direct connection by TDLS is established between the terminal 101 during power saving control and the terminal 102 not executing power saving control. It is a sequence diagram which shows the example of operation | movement. In a state where the terminal 102 can receive the beacon from the AP 103 (F501), the terminal 102 can receive an ICMP Echo Request (F502) from the terminal 101, and therefore can respond with an ICMP Echo Reply (F503).

  On the other hand, when the terminal 102 moves out of the communicable range with the AP 103, the AP 103 cannot receive the beacon (F504), and the connection between the terminal 102 and the AP 103 is interrupted. In such a situation, even if transmission data addressed to the terminal 101 is generated in the terminal 102, the TDLS Peer Traffic Indication cannot be transmitted via the AP 103 (F505).

  On the other hand, when a predetermined period has elapsed since the last survival confirmation, the terminal 101 transmits an ICMP Echo Request again to the terminal 102 (F506). Since the terminal 102 is out of the communicable range of the AP 103, it cannot receive this ICMP Echo Request. Therefore, the terminal 101 does not receive the ICMP Echo Reply from the terminal 102 within a predetermined time. For this reason, the terminal 101 determines that the connection between the terminal 102 and the AP 103 has been interrupted, and ends the power saving control (F507).

  Then, the terminal 101 transmits a TLDS Peer Traffic Response using direct communication in order to notify the terminal 102 that the power saving control has ended (F508). The terminal 102 can determine that the terminal 101 has returned from the power saving control by receiving the TDLS Peer Traffic Response, and in response thereto, transmits data using direct communication (F509).

  As described above, even when the connection between the terminal 102 and the AP 103 is interrupted, the terminal 101 can confirm the disconnection and cancel the power saving state. Accordingly, the terminal 101 can maintain direct communication with the terminal 102 even when the communication environment is changed and communication via the AP 103 becomes impossible during the power saving control.

<< Embodiment 2 >>
In the first embodiment, an example is shown in which the terminal 101 ends the power saving control after detecting the disconnection of the connection with the terminal 102 via the AP 103 and continues the communication with the terminal 102 through the direct link. . On the other hand, this embodiment shows a configuration in which communication is continued by forming an ad hoc network with the terminal 102 after the terminal 101 detects a communication interruption with the terminal 102 via the AP 103.

  Note that the configuration of the wireless communication system according to the present embodiment and the hardware configuration of the terminal are the same as those in the first embodiment, and thus description thereof is omitted.

(Terminal configuration)
FIG. 6 is a block diagram illustrating a configuration example of functions of the terminal 101 and the terminal 102 according to the present embodiment. In addition, about the function similar to Embodiment 1 (FIG. 3), the same reference number is attached | subjected and the description is abbreviate | omitted. In addition to the configuration of the first embodiment, the terminal 101 and the terminal 102 further have an ad hoc communication function 314. The ad hoc communication function 314 includes an ad hoc network control unit 315, an ad hoc data transmission / reception unit 316, and an ad hoc network role determination unit 317.

  The ad hoc network control unit 315 performs control for forming, joining, and leaving the ad hoc network. The ad hoc data transmission / reception unit 316 executes at least one of data transmission and reception in the ad hoc network. The ad hoc network role determination unit 317 negotiates with the partner device whether to play the role of creating or participating in the ad hoc network.

(Device operation)
FIG. 7 is a flowchart showing a flow of processing executed by the terminal 101 or the terminal 102 according to the present embodiment during power saving control. Each process of FIG. 7 is performed by reading and executing the computer program stored in the storage unit 203 by the control unit 202, similarly to the processes of FIG. In the following, it is assumed that the terminal 101 is executing power saving control. The processing steps from S701 to S716 are the same as the processing steps from S401 to S416 in FIG.

  In step S717, the terminal 101 notifies the terminal 102 that the power saving control has been completed by transmitting a peer traffic response to the terminal 102 by direct communication. Here, in addition to this, the terminal 101 according to the present embodiment notifies the terminal 102 of a request for transition to the ad hoc network. This is realized, for example, by adding an information element indicating an ad hoc network migration request to the information element of the TDLS Peer Traffic Response. Thereafter, the terminal 101 activates the ad hoc network role determination unit 317 and determines a role with the terminal 102 (S718).

  When the terminal 101 has a role of generating a network according to the determination in S718, the ad hoc network control unit 315 generates an ad hoc network (S719). On the other hand, when it becomes a role to participate in the network by the determination in S718, the terminal 101 participates in the ad hoc network generated by the terminal 102 by the ad hoc network control unit 315 (S720).

(System operation)
FIG. 8 illustrates a case where communication between the terminal 102 and the AP 103 is interrupted when a direct connection by TDLS is established between the terminal 101 that is in power saving control and the terminal 102 that is not executing power saving control. It is a sequence diagram which shows the operation example of the system which concerns on this embodiment. Note that the operations from F801 to F804 are the same as the operations from F504 to F507 in the first embodiment, and thus description thereof is omitted.

  The terminal 101 determines that the connection between the terminal 102 and the AP 103 has been interrupted, ends the power saving control, and transmits a TLDS Peer Traffic Response to the terminal 102 by direct connection (F805). At this time, in addition to the TDLS Peer Traffic Response, the terminal 101 notifies an information element indicating a request for transition to an ad hoc network.

  In addition, the terminal 101 activates an ad hoc network role determination function. The terminal 102 also activates the ad hoc network role determination function in response to receiving the TDLS Peer Traffic Response. Thereby, the role determination of the ad hoc network is executed between the terminal 101 and the terminal 102 (F806).

  Here, it is assumed that the terminal 102 is the ad hoc network generation side and the terminal 101 is the ad hoc network participation side. The terminal 102 generates an ad hoc network (F807). Then, the terminal 101 participates in the ad hoc network generated by the terminal 102 (F808). On the ad hoc network formed in this way, the terminal 101 and the terminal 102 perform data transmission / reception (F809).

  As described above, in the present embodiment, after detecting the disconnection of the connection with the terminal 102 via the AP 103, the power saving control is terminated and an ad hoc network can be formed with the terminal 102. Therefore, the terminal 101 can maintain communication with the terminal 102 even when the communication environment is changed during the power saving control and communication via the AP 103 becomes impossible.

<< Embodiment 3 >>
In the second embodiment, after the terminal 101 detects the disconnection of the connection with the terminal 102 via the AP 103, the power saving control is terminated, and communication is performed by forming an ad hoc network with the terminal 102. The continued configuration was shown. On the other hand, in this embodiment, after the terminal 101 detects a communication interruption with the terminal 102 via the AP 103, the terminal 101 or the terminal 102 operates the simple access point function, and the other terminal connects to this. The structure which continues communication by doing is shown.

  Note that the configuration of the wireless communication system according to the present embodiment and the hardware configuration of the terminal are the same as those in the first and second embodiments, and thus description thereof is omitted.

(Terminal configuration)
FIG. 9 is a block diagram illustrating a configuration example of functions of the terminal 101 and the terminal 102 according to the present embodiment. In addition, about the function similar to Embodiment 1 (FIG. 3), the same reference number is attached | subjected and the description is abbreviate | omitted. In addition to the configuration of the first embodiment, the terminal 101 and the terminal 102 further include a simple access point function 318 and a simple access point / station role determination unit 321. The simple access point function 318 is a function for a terminal to operate as a wireless LAN access point and connect another wireless terminal. Further, the simple access point / station role determination unit 321 negotiates with the opposite terminal whether to play a role of generating or participating in the wireless LAN network.

  The simple access point function 318 includes, for example, a simple access point control unit 319 and a simple access point data transmission / reception unit 320. The simple access point control unit 319 generates and manages a wireless LAN network. The simple access point data transmission / reception unit 320 performs data transmission / reception with other terminals connected to the simple access point.

(Device operation)
FIG. 10 is a flowchart illustrating a flow of processing executed by the terminal 101 or the terminal 102 according to the present embodiment during power saving control. Each process of FIG. 10 is performed by reading and executing the computer program stored in the storage unit 203 by the control unit 202, similarly to the processes of FIG. 4 or FIG. In the following, it is assumed that the terminal 101 is executing power saving control. Further, the processing steps from S1001 to S1016 are the same as the processing steps from S401 to S416 in FIG.

  In step S1017, the terminal 101 notifies the terminal 102 that the power saving control has been completed by transmitting a peer traffic response to the terminal 102 by direct communication. Here, in addition to this, the terminal 101 according to the present embodiment notifies the terminal 102 of a request for shifting to the connection by the simple access point function. This is realized, for example, by adding an information element indicating a request for transition to the simple access point connection to the information element of the TDLS Peer Traffic Response. After that, the terminal 101 activates the simple access point / station role determining unit 321 and determines a role with the terminal 102 (S1018).

  When the terminal 101 assumes the role of a simple access point according to the determination in S1018, the simple access point control unit 319 generates a wireless LAN infrastructure network (S1019). On the other hand, when the terminal 101 becomes a role by the determination in S1018, the infrastructure network control unit 309 causes the terminal 101 to participate in the wireless LAN infrastructure network generated by the terminal 102 (S1020).

  Note that the role determination in the simple access point / station role determination unit in S1018 may be performed by comparing the MAC addresses of both terminals or by comparing values indicating the strength of the tendency to become simple access points of both terminals. Further, a message used for determining a role may be added to a data frame, an action frame, or a search signal on TDLS direct communication.

(System operation)
FIG. 11 illustrates a case where communication between the terminal 102 and the AP 103 is interrupted when a direct connection by TDLS is established between the terminal 101 that is in power saving control and the terminal 102 that is not executing power saving control. It is a sequence diagram which shows the operation example of the system which concerns on this embodiment. Since each operation from F1101 to F1104 is the same as each operation from F504 to F507 in the first embodiment, a description thereof will be omitted.

  The terminal 101 determines that the communication between the terminal 102 and the AP 103 has been interrupted, ends the power saving control, and transmits a TLDS Peer Traffic Response to the terminal 102 through direct communication (F1105). At this time, in addition to the TDLS Peer Traffic Response, the terminal 101 notifies an information element indicating a request for transition to the simple access point connection.

  In addition, the terminal 101 activates a simple access point / station role determination function. In response to receiving the TDLS Peer Traffic Response, the terminal 102 also activates the simple access point / station role determination function. As a result, a role determination as to which of the terminals 101 and 102 becomes the simple access point is executed (F1106).

  Here, it is assumed that the terminal 102 is the simple access point side and the terminal 101 is the station side. The terminal 102 generates an infrastructure network (F1107). Then, the terminal 101 participates in the infrastructure network generated by the terminal 102 (F1108). On the network thus formed, the terminal 101 and the terminal 102 perform data transmission / reception (F1109).

  As described above, in this embodiment, after detecting the disconnection of the connection with the terminal 102 via the AP 103, the power saving control is terminated and the simple access point function is used to connect the terminal 102 and the infrastructure. A structure network can be formed. Therefore, the terminal 101 can maintain communication with the terminal 102 even when the communication environment is changed during the power saving control and communication via the AP 103 becomes impossible.

<< Other Embodiments >>
Although several embodiments have been described above, these are illustrative examples, and the scope of the present invention is not intended to be limited only to these embodiments. The embodiment can be variously modified without departing from the gist of the present invention. Also, the above description has been made with reference to an IEEE 802.11-compliant wireless LAN as an example. However, the present invention may be implemented in other wireless media such as wireless USB, MBOA, Bluetooth (registered trademark), UWB, and ZigBee. Here, MBOA is an abbreviation for Multi Band OFDM Alliance. UWB includes wireless USB, wireless 1394, WINET, and the like.

  The present invention can also be realized by executing the following processing. That is, software (program) that realizes the functions of the above-described embodiments is supplied to a system or apparatus via a network or various storage media, and a computer (or CPU, MPU, or the like) of the system or apparatus reads the program. It is a process to be executed.

Claims (15)

A first communication function that directly connects to the counterpart device, and a second communication device that connects to the counterpart device via another device and executes at least part of communication for establishing a connection by the first communication function. A communication device having communication means connectable to the counterpart device using a communication function,
Determination means for determining whether the connection is interrupted in a state where the connection with the counterpart device is established by the second communication function;
Control means for controlling to end the power saving control when it is determined that the connection is interrupted during the power saving control;
A communication apparatus comprising: The communication means notifies the counterpart device by the first communication function that the power saving control has been terminated;
The communication apparatus according to claim 1. The determination means transmits a predetermined signal to the counterpart device and receives a response to the predetermined signal from the counterpart device by the second communication function, or the predetermined signal from the counterpart device To determine whether the connection is lost depending on whether
The communication apparatus according to claim 1 or 2, wherein The determination means transmits the predetermined signal every predetermined time.
The communication apparatus according to claim 3. The predetermined signal is ICMP Echo Request.
The communication apparatus according to claim 3 or 4, wherein The response is ICMP Echo Reply.
The communication apparatus according to any one of claims 3 to 5, wherein: The determination unit determines whether the connection is interrupted according to whether the second communication function receives a predetermined signal from the other device at a predetermined period.
The communication apparatus according to claim 1 or 2, wherein A limiting unit that limits supply of power to the communication unit during execution of the power saving control;
The communication device according to claim 1, wherein the communication device is a device. The limiting unit does not limit the supply of power to the communication unit during a period for transmission or reception of a signal for determination by the determination unit.
The communication apparatus according to claim 8. The communication device includes a first communication unit that executes communication by the first communication function, and a second communication unit that executes communication by the second communication function.
The communication apparatus according to any one of claims 1 to 9, wherein The communication device communicates with the counterpart device by the first communication function when it is determined that the connection is interrupted during the power saving control.
The communication device according to any one of claims 1 to 10, wherein: The communication means is further connectable to the counterpart device by an ad hoc network,
The communication means starts communication with the counterpart device by the ad hoc network when it is determined that the connection has been interrupted during the power saving control.
The communication device according to any one of claims 1 to 10, wherein: The communication means is further connectable with the counterpart device by generating a network and the counterpart device joining the network, or by joining the network generated by the counterpart device,
When it is determined that the connection has been interrupted while the power saving control is being performed, the communication unit generates a network and the partner device joins the network, or the network generated by the partner device Start communication with the partner device by joining,
The communication device according to any one of claims 1 to 10, wherein: A first communication function that directly connects to the counterpart device, and a second communication device that connects to the counterpart device via another device and executes at least part of communication for establishing a connection by the first communication function. A communication device control method comprising a communication means connectable to the counterpart device using a communication function,
A determination step of determining whether the connection is interrupted in a state in which the determination unit is connected to the counterpart device by the second communication function;
When the control means determines that the connection has been interrupted during execution of power saving control, a control step for controlling the power saving control to be terminated, and
A control method characterized by comprising: A first communication function that directly connects to the counterpart device, and a second communication device that connects to the counterpart device via another device and executes at least part of communication for establishing a connection by the first communication function. In a computer provided in a communication device having a communication means connectable to the counterpart device using a communication function,
A determination step of determining whether or not the connection is interrupted in a state where the connection with the counterpart device is established by the second communication function;
A control step of controlling to end the power saving control when it is determined that the connection is interrupted during the power saving control;
A program for running

Images