JP2013240010A - Radio communication system, radio communication device and communication control method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To satisfactorily perform communication between a radio terminal device in a network, in which a plurality of radio terminal devices can mutually perform radio communication, and a device in another network.SOLUTION: A radio communication system 301 includes: a plurality of radio terminal devices 202 capable of mutually performing radio communication; and a radio communication device 101 for relaying communication data transmitted and received between a device other than the plurality of radio terminal devices 202 and the plurality of radio terminal devices 202 by performing radio communication with a connection terminal, which is one of the radio terminal devices 202 among the plurality of radio terminal devices 202. A radio communication system 301 includes: a state comparison unit 12 for comparing the state of the connection terminal with each state of the other radio terminal devices 202; and a terminal selection unit 14 for newly selecting a connection terminal from among the plurality of radio terminal devices 202, based on the comparison result of the state comparison unit 12.

Description

  The present invention relates to a radio communication system, a radio communication apparatus, and a communication control method, and in particular, a radio communication system in which a plurality of radio terminal apparatuses can perform radio communication with each other, and a radio communication apparatus and communication control in the radio communication system. Regarding the method.

  In an ad hoc network, personal computers, PDAs (Personal Digital Assistants), mobile phones, and the like can perform wireless communication with each other without going through a wireless base station device or an access point, so that a network can be constructed at low cost. (For example, refer to "Ad hoc network and wireless LAN mesh network", IEICE Transactions_B_Vol.J89-B_No.6_pp.811-823, Shiro Sakata et al., 2006 (non-patent document 1)) .

  In addition, as a method for performing communication between a wireless terminal device in an ad hoc network and a device in an external network such as the Internet, for example, the following method can be considered.

  That is, any one of a plurality of wireless terminal devices in an ad hoc network is set as an external network connection terminal, the external network connection terminal is connected to a wireless base station device or an access point, and the devices are connected via these devices. To perform the communication.

"Ad Hoc Network and Wireless LAN Mesh Network", IEICE Transactions_B_Vol.J89-B_No.6_pp.811-823, Shiro Sakata et al., 2006

  However, in the method as described above, when the external network connection terminal moves and moves away from the radio base station apparatus or access point, the radio wave condition between the external network connection terminal and the radio base station apparatus or access point becomes worse, Communication becomes unstable. Further, for example, the transmission power of the radio signal from the external network connection terminal to the radio base station apparatus or the access point increases, so that the power consumption of the external network connection terminal increases.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a connection between a wireless terminal device in a network in which a plurality of wireless terminal devices can perform wireless communication with each other and a device in another network. It is to provide a wireless communication system, a wireless communication apparatus, and a communication control method capable of performing good communication with each other.

  (1) In order to solve the above problems, a wireless communication system according to an aspect of the present invention includes a plurality of wireless terminal devices capable of performing wireless communication with each other, and any one of the plurality of wireless terminal devices. A wireless communication device for relaying communication data transmitted and received between a device other than the plurality of wireless terminal devices and the plurality of wireless terminal devices by performing wireless communication with a connection terminal which is one wireless terminal device A wireless communication system comprising: a state comparison unit for comparing a state of the connection terminal with a state of another wireless terminal device; and the plurality of wirelesss based on a comparison result by the state comparison unit A terminal selection unit for newly selecting the connection terminal from among the terminal devices.

  With such a configuration, the connection terminal can be switched when the state of the connection terminal becomes worse than the state of other wireless terminal apparatuses, so the radio wave condition between the connection terminal and the wireless communication apparatus is good. To stabilize the communication. In addition, it is possible to prevent the transmission power of the radio signal from the connection terminal to the wireless communication apparatus from increasing, and to prevent an increase in power consumption of the connection terminal. Therefore, it is possible to satisfactorily perform communication between a wireless terminal device in a network in which a plurality of wireless terminal devices can perform wireless communication with each other and devices in other networks. In addition, the configuration for comparing with the state of the wireless terminal device other than the connection terminal, for example, inappropriate connection when the state of the other wireless terminal device is worse even if the state of the connection terminal is bad It is possible to prevent terminal switching.

  (2) Preferably, the wireless communication system further includes a state determination unit for determining whether or not a state of the connection terminal satisfies a predetermined condition, and the state selection unit includes the state determination unit. When it is determined that the predetermined condition is satisfied, the connection terminal is selected.

  With such a configuration, when the state of the connected terminal is good to some extent, it is possible to prevent the connected terminal from being switched, and thus preventing frequent switching of the connected terminal and unstable communication. it can.

  (3) Preferably, the state is a state of receiving a radio wave from the wireless communication device.

  With such a configuration, it is possible to appropriately select a wireless terminal device having a good communication state with the wireless communication device as a connection terminal.

  (4) Preferably, the state is a battery state.

  With such a configuration, it is possible to prevent the wireless terminal device from consuming electric power due to the operation as a connection terminal, and the battery of a specific wireless terminal device is not likely to run out. Thus, communication in an ad hoc network can be continued stably. be able to.

  (5) A wireless communication system according to another aspect of the present invention includes a plurality of wireless terminal devices capable of performing wireless communication with each other and any one of the plurality of wireless terminal devices. A wireless communication system comprising a wireless communication device for relaying communication data transmitted and received between a device other than the plurality of wireless terminal devices and the plurality of wireless terminal devices by performing wireless communication with a certain connection terminal A state determination unit for determining whether or not the state of the connection terminal satisfies a predetermined condition; and when the state determination unit determines that the predetermined condition is satisfied, the plurality of wireless terminal devices A terminal selection unit for newly selecting the connection terminal from the inside.

  With such a configuration, when the state of the connection terminal deteriorates, the connection terminal can be switched, so that the radio wave state between the connection terminal and the wireless communication device is kept good and the communication is stabilized. Can do. In addition, it is possible to prevent the transmission power of the radio signal from the connection terminal to the wireless communication apparatus from increasing, and to prevent an increase in power consumption of the connection terminal.

  (6) In order to solve the above-described problem, a wireless communication device according to an aspect of the present invention is a connection that is any one of a plurality of wireless terminal devices capable of performing wireless communication with each other. A wireless communication device for relaying communication data transmitted and received between a device other than the plurality of wireless terminal devices and the plurality of wireless terminal devices by performing wireless communication with a terminal, wherein the connection terminal In order to newly select the connection terminal from among the plurality of wireless terminal devices based on the comparison result by the state comparison unit for comparing the state and the state of the other wireless terminal device and the state comparison unit Terminal selection unit.

  With such a configuration, the connection terminal can be switched when the state of the connection terminal becomes worse than the state of other wireless terminal apparatuses, so the radio wave condition between the connection terminal and the wireless communication apparatus is good. To stabilize the communication. In addition, it is possible to prevent the transmission power of the radio signal from the connection terminal to the wireless communication apparatus from increasing, and to prevent an increase in power consumption of the connection terminal. Therefore, it is possible to satisfactorily perform communication between a wireless terminal device in a network in which a plurality of wireless terminal devices can perform wireless communication with each other and devices in other networks. In addition, the configuration for comparing with the state of the wireless terminal device other than the connection terminal, for example, inappropriate connection when the state of the other wireless terminal device is worse even if the state of the connection terminal is bad It is possible to prevent terminal switching.

  (7) A wireless communication apparatus according to another aspect of the present invention performs wireless communication with a connection terminal that is any one of a plurality of wireless terminal apparatuses capable of performing wireless communication with each other. Thus, a wireless communication device for relaying communication data transmitted / received between a device other than the plurality of wireless terminal devices and the plurality of wireless terminal devices, wherein the state of the connection terminal satisfies a predetermined condition And a terminal selection for newly selecting the connection terminal from the plurality of wireless terminal devices when the state determination unit determines whether or not the predetermined condition is satisfied. A part.

  With such a configuration, when the state of the connection terminal deteriorates, the connection terminal can be switched, so that the radio wave state between the connection terminal and the wireless communication device is kept good and the communication is stabilized. Can do. In addition, it is possible to prevent the transmission power of the radio signal from the connection terminal to the wireless communication apparatus from increasing, and to prevent an increase in power consumption of the connection terminal.

  (8) In order to solve the above problem, a communication control method according to an aspect of the present invention includes a plurality of wireless terminal devices capable of performing wireless communication with each other, and any one of the plurality of wireless terminal devices. A wireless communication device for relaying communication data transmitted and received between a device other than the plurality of wireless terminal devices and the plurality of wireless terminal devices by performing wireless communication with a connection terminal which is one wireless terminal device A communication control method in a wireless communication system comprising: a step of comparing a state of the connection terminal with a state of another wireless terminal device; and from among the plurality of wireless terminal devices based on a comparison result Selecting a new connection terminal.

  With such a configuration, the connection terminal can be switched when the state of the connection terminal becomes worse than the state of other wireless terminal apparatuses, so the radio wave condition between the connection terminal and the wireless communication apparatus is good. To stabilize the communication. In addition, it is possible to prevent the transmission power of the radio signal from the connection terminal to the wireless communication apparatus from increasing, and to prevent an increase in power consumption of the connection terminal. Therefore, it is possible to satisfactorily perform communication between a wireless terminal device in a network in which a plurality of wireless terminal devices can perform wireless communication with each other and devices in other networks. In addition, the configuration for comparing with the state of the wireless terminal device other than the connection terminal, for example, inappropriate connection when the state of the other wireless terminal device is worse even if the state of the connection terminal is bad It is possible to prevent terminal switching.

  (9) A communication control method according to another aspect of the present invention includes a plurality of wireless terminal devices capable of performing wireless communication with each other, and any one of the plurality of wireless terminal devices. A wireless communication system comprising a wireless communication device for relaying communication data transmitted and received between a device other than the plurality of wireless terminal devices and the plurality of wireless terminal devices by performing wireless communication with a certain connection terminal And determining whether or not the state of the connection terminal satisfies a predetermined condition, and when determining that the predetermined condition is satisfied, the connection terminal is selected from the plurality of wireless terminal devices. A new selection step.

  With such a configuration, when the state of the connection terminal deteriorates, the connection terminal can be switched, so that the radio wave state between the connection terminal and the wireless communication device is kept good and the communication is stabilized. Can do. In addition, it is possible to prevent the transmission power of the radio signal from the connection terminal to the wireless communication apparatus from increasing, and to prevent an increase in power consumption of the connection terminal.

  According to the present invention, it is possible to satisfactorily perform communication between a wireless terminal device in a network in which a plurality of wireless terminal devices can perform wireless communication with each other and devices in other networks.

It is a figure which shows the structure of the radio | wireless communications system which concerns on embodiment of this invention. It is a figure which shows a mode that an external network connection terminal moves in the radio | wireless communications system which concerns on embodiment of this invention. It is a figure which shows the dynamic switching of the external network connection terminal in the radio | wireless communications system which concerns on embodiment of this invention. It is a figure which shows the structure of the access point which concerns on embodiment of this invention. It is a figure which shows the structure of the radio | wireless terminal apparatus which concerns on embodiment of this invention. It is a figure which shows the structure of the control part in the radio | wireless terminal apparatus or access point which concerns on embodiment of this invention. It is a figure which shows an example of the sequence of the switching process of the external network connection terminal in the radio | wireless communications system which concerns on embodiment of this invention. It is a figure which shows an example of the switching process of the external network connection terminal in the radio | wireless communications system which concerns on embodiment of this invention. It is a figure which shows an example of the sequence of the switching process of the external network connection terminal in the radio | wireless communications system which concerns on embodiment of this invention. It is a figure which shows an example of the switching process of the external network connection terminal in the radio | wireless communications system which concerns on embodiment of this invention. It is a figure which shows an example of the sequence of the connection process (passive scan) with the radio | wireless terminal apparatus and access point in the radio | wireless communications system which concerns on embodiment of this invention. It is a figure which shows an example of the sequence of the connection process (active can) of the radio | wireless terminal apparatus and access point in the radio | wireless communications system which concerns on embodiment of this invention. It is a figure which shows an example of the sequence of the switching process of the external network connection terminal in the radio | wireless communications system which concerns on embodiment of this invention. It is a figure which shows an example of the sequence of the switching process of the external network connection terminal in the radio | wireless communications system which concerns on embodiment of this invention.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals and description thereof will not be repeated.

[Configuration and basic operation]
FIG. 1 is a diagram showing a configuration of a radio communication system according to an embodiment of the present invention.

  Referring to FIG. 1, a wireless communication system 301 includes an access point (AP) (wireless communication apparatus) 101 and wireless terminal apparatuses 202A, 202B, 202C, 202D. Hereinafter, each of the wireless terminal devices 202A, 202B, 202C, and 202D may be referred to as a wireless terminal device 202.

  The wireless terminal devices 202A, 202B, 202C, 202D and the access point 101 perform wireless communication in accordance with, for example, a wireless LAN standard defined by IEEE 802.11.

  The wireless terminal devices 202A, 202B, 202C, and 202D can perform wireless communication with each other, and constitute an ad hoc network 401. In FIG. 1, four wireless terminal devices in the ad hoc network 401 are representatively shown, but a smaller number or a larger number of wireless terminal devices may be provided.

  As shown by a dotted line in FIG. 1, for example, when the wireless terminal device 202A is an external network connection terminal, the wireless terminal device 202A transmits a wireless signal received from another wireless terminal device 202 to the access point 101, and The wireless signal received from the access point 101 is transmitted to another wireless terminal device 202.

  The access point 101 performs wireless communication with a network connection terminal that is any one of the plurality of wireless terminal devices 202, whereby the access point 101 communicates with a device other than the plurality of wireless terminal devices 202 and the plurality of wireless devices. The communication data transmitted / received to / from the terminal device 202 is relayed. More specifically, the access point 101 transmits communication data included in a radio signal received from an external network connection terminal to the IP network 402, and converts the communication data received from the IP network 402 into a radio signal to be externally transmitted. Send to the network connection terminal. Note that the access point 101 is not limited to the IP network 402, and may be any configuration that relays communication data transmitted and received between a device outside the ad hoc network 401 and the wireless terminal device 202.

  The wireless terminal device 202 can communicate with the access point 101 via another wireless terminal device 202 even when the wireless terminal device 202 exists at a position away from the access point 101. In addition, the wireless terminal devices 202A, 202B, 202C, and 202D perform wireless communication with each other, thereby preventing processing of the access point 101 and an increase in communication traffic.

  FIG. 2 is a diagram illustrating a situation in which an external network connection terminal moves in the wireless communication system according to the embodiment of the present invention.

  Referring to FIG. 2, when radio terminal apparatus 202A, which is an external network connection terminal, moves away from access point 101, the radio wave condition between the external network connection terminal and access point 101 changes due to distance, radio wave interference, and the like. Deteriorate. Then, delay and disconnection occur in communication between the wireless terminal devices 202A, 202B, 202C, and 202D and the IP network 402. In addition, if the wireless terminal device 202A and the access point 101 increase the transmission power of a wireless signal, for example, in order to improve the communication, the power consumption of the wireless terminal device 202A and the access point 101 increases.

  Therefore, in the wireless communication system 301 according to the embodiment of the present invention, a stable network is constructed by dynamically switching an external network connection terminal serving as a starting point according to a communication state.

  FIG. 3 is a diagram showing dynamic switching of external network connection terminals in the wireless communication system according to the embodiment of the present invention.

  Specifically, referring to FIG. 3, when wireless terminal device 202A, which is an external network connection terminal, moves and moves away from access point 101, it exists at a position closer to access point 101 than wireless terminal device 202A. A wireless terminal device 202B having a good communication state with the point 101 is newly selected as an external network connection terminal.

  Thereby, it is possible to maintain good communication between the wireless terminal apparatuses 202A, 202B, 202C, and 202D and the IP network 402, and to prevent an increase in power consumption of the wireless terminal apparatus 202A and the access point 101.

  FIG. 4 is a diagram showing the configuration of the access point according to the embodiment of the present invention.

  Referring to FIG. 4, access point 101 includes an antenna 91, a circulator 92, a wireless reception unit 93, a wireless transmission unit 94, a signal processing unit 95, and a control unit 98. The signal processing unit 95 includes a reception signal processing unit 96 and a transmission signal processing unit 97. The signal processing unit 95 and the control unit 98 are realized by a CPU (Central Processing Unit) or a DSP (Digital Signal Processor).

  The circulator 92 outputs the radio signal from the radio terminal device 202 received by the antenna 91 to the radio reception unit 93 and outputs the radio signal received from the radio transmission unit 94 to the antenna 91.

  Radio receiving section 93 converts the radio signal received from circulator 92 into a baseband signal or IF (Intermediate Frequency) signal, converts the frequency-converted signal into a digital signal, and outputs the digital signal to received signal processing section 96.

  The reception signal processing unit 96 performs predetermined signal processing on the digital signal received from the wireless reception unit 93, converts a part or all of the digital signal after the signal processing into a predetermined frame format, and converts it into the IP network 402. Send to.

  The transmission signal processing unit 97 performs predetermined signal processing on communication data obtained by converting communication data received from the IP network 402 into a predetermined frame format or communication data generated by itself, and wirelessly transmits the digital signal after the signal processing. The data is output to the transmission unit 94.

  The radio transmission unit 94 converts the digital signal received from the transmission signal processing unit 97 into an analog signal, converts the frequency of the converted analog signal into a radio signal, and outputs the radio signal to the circulator 92.

  The control unit 98 exchanges various types of information with each unit in the access point 101 and the IP network 402.

  FIG. 5 is a diagram showing the configuration of the wireless terminal apparatus according to the embodiment of the present invention.

  Referring to FIG. 5, wireless terminal apparatus 202 includes antenna 81, circulator 82, wireless receiver 83, wireless transmitter 84, signal processor 85, controller 88, and input / output unit 89. Prepare. The signal processing unit 85 includes a reception signal processing unit 86 and a transmission signal processing unit 87. The signal processing unit 85 and the control unit 88 are realized by a CPU (Central Processing Unit), a DSP (Digital Signal Processor), or the like.

  Circulator 82 outputs a radio signal from access point 101 received at antenna 81 to radio reception unit 83 and outputs a radio signal received from radio transmission unit 84 to antenna 81.

  Radio receiving section 83 converts the radio signal received from circulator 82 into a baseband signal or IF (Intermediate Frequency) signal, converts the frequency-converted signal into a digital signal, and outputs the digital signal to received signal processing section 86.

  The reception signal processing unit 86 performs predetermined signal processing on the digital signal received from the wireless reception unit 83, and outputs a part or all of the digital signal after this signal processing to the control unit 88.

  The control unit 88 converts the digital signal received from the reception signal processing unit 86 into, for example, audio data and video data, and converts it into an analog signal as necessary. And the control part 88 outputs to the input-output part 89 containing a speaker, a microphone, a display, a key input device, etc.

  Further, the control unit 88 receives, for example, voice data and a control signal for controlling the wireless terminal device 202 received by the key input device from the input / output unit 89. Control unit 88 performs predetermined signal processing on the audio data and control signal received from input / output unit 89 to generate communication data, and outputs the communication data to transmission signal processing unit 87.

  The transmission signal processing unit 87 performs predetermined signal processing on the communication data received from the control unit 88 or the communication data generated by itself, and outputs the digital signal after this signal processing to the wireless transmission unit 84.

  The wireless transmission unit 84 converts the digital signal received from the transmission signal processing unit 87 into an analog signal, converts the frequency of the converted analog signal into a wireless signal, and outputs the radio signal to the circulator 82.

  FIG. 6 is a diagram showing a configuration of a control unit in the wireless terminal device or the access point according to the embodiment of the present invention.

  Referring to FIG. 6, control unit 88 or control unit 98 includes a terminal state acquisition unit 11, a state comparison unit 12, a state determination unit 13, and a terminal selection unit 14.

  The terminal state acquisition unit 11 acquires the state of each wireless terminal device 202 in the ad hoc network 401. Specifically, the terminal state acquisition unit 11 acquires, for example, a reception state of radio waves from the access point 101 in the wireless terminal device 202 or acquires a battery state of the wireless terminal device 202.

  The state comparison unit 12 compares the state of the network connection terminal acquired by the terminal state acquisition unit 11 with the state of the other wireless terminal device 202.

  The terminal selection unit 14 newly selects a network connection terminal from a plurality of wireless terminal devices 202 in the ad hoc network 401 based on the comparison result by the state comparison unit 12.

  The state determination unit 13 determines whether the state of the network connection terminal acquired by the terminal state acquisition unit 11 satisfies a predetermined condition.

  For example, the terminal selection unit 14 selects a network connection terminal when the state determination unit 13 determines that the predetermined condition is satisfied.

[Operation]
Next, an operation when the wireless terminal device and the access point according to the embodiment of the present invention perform the switching process of the external network connection terminal will be described.

  The wireless terminal device and the access point in the wireless communication system according to the embodiment of the present invention read and execute a program including each step of the following sequences from a memory (not shown). This program can be installed externally. The installed program is distributed in a state stored in a recording medium, for example.

  FIG. 7 is a diagram showing an exemplary sequence of a switching process of external network connection terminals in the wireless communication system according to the embodiment of the present invention.

  Referring to FIG. 7, in a state where wireless terminal apparatus 202A, which is an external network connection terminal, and access point 101 are communicating by transmitting and receiving wireless signals (step S11), first, wireless terminal apparatus 202A is a wireless terminal. A reception radio wave information request is transmitted to apparatus 202B. The wireless terminal device 202A transmits a received radio wave information request periodically or when a predetermined condition is satisfied (step S12).

  Next, the wireless terminal device 202B receives the received radio wave information request from the wireless terminal device 202A, and transmits, for example, received radio wave information indicating the received power of the radio signal from the access point 101 to the wireless terminal device 202A ( Step S13). Although not shown in FIG. 7, for example, the wireless terminal device 202A transmits a received radio wave information request to a wireless terminal device 202 other than the wireless terminal device 202B, and acquires the received radio wave information.

  Next, 202 A of radio | wireless terminal apparatuses determine the radio wave state of each radio | wireless terminal apparatus 202 including self based on the received radio wave information received from each radio | wireless terminal apparatus 202. FIG. Specifically, for example, if the difference between the received power of the wireless signal from the access point 101 and the received power of the other wireless terminal device 202 is equal to or greater than a predetermined threshold, the wireless terminal device 202A It is determined that the network connection terminal should be switched from itself to another wireless terminal device 202 (step S14).

  Next, the wireless terminal device 202A selects, for example, the wireless terminal device 202B having the maximum received power as a new external network connection terminal (step S15), and transmits a connection instruction to the wireless terminal device 202B (step S16). .

  Next, the wireless terminal device 202B receives a connection instruction from the wireless terminal device 202A, performs connection processing with the access point 101 as described later (step S17), and thereafter operates as an external network connection terminal.

  Next, the wireless terminal device 202A and the access point 101 perform a process of disconnecting communication connection with each other (step S18).

  FIG. 8 is a diagram showing an example of switching processing of the external network connection terminal in the wireless communication system according to the embodiment of the present invention.

  Referring to FIG. 8, first, the radio wave condition between radio terminal apparatus 202A, which is an external network connection terminal, and access point 101 is good, and the radio wave condition between radio terminal apparatus 202B and access point 101 is normal. Consider a situation where the radio wave condition between the wireless terminal device 202C and the access point 101 is poor.

  In this situation, when the wireless terminal device 202A moves and moves away from the access point 101, the radio wave condition between the wireless terminal device 202A and the access point 101 becomes worse. Then, the wireless terminal device 202A selects the wireless terminal device 202B having the best radio wave state as a new external network connection terminal, and thereafter, the wireless terminal device 202B operates as the external network connection terminal.

  FIG. 9 is a diagram showing an exemplary sequence of switching processing of external network connection terminals in the wireless communication system according to the embodiment of the present invention.

  Referring to FIG. 9, in a state where wireless terminal apparatus 202A, which is an external network connection terminal, and access point 101 are communicating by transmitting and receiving wireless signals (step S21), first, wireless terminal apparatus 202A is a wireless terminal. A battery information request is transmitted to the device 202B. The wireless terminal device 202A transmits a battery information request periodically or when a predetermined condition is satisfied (step S22).

  Next, the wireless terminal device 202B receives the battery information request from the wireless terminal device 202A, and transmits the battery information to the wireless terminal device 202A. Although not shown in FIG. 9, the wireless terminal device 202A transmits a battery information request to the wireless terminal devices 202 other than the wireless terminal device 202B, for example, and acquires battery information. This battery information indicates, for example, a state where the battery of the wireless terminal device 202 is being charged, a state where the remaining amount of the battery is greater than or equal to a threshold, or a state where the remaining amount of the battery is less than the threshold (step S23). .

  Next, 202 A of radio | wireless terminal apparatuses determine the battery remaining charge of each radio | wireless terminal apparatus 202 including self based on the battery information received from each radio | wireless terminal apparatus 202, for example. Specifically, for example, when the difference between the remaining battery level of the wireless terminal device 202A and the remaining battery level of the other wireless terminal device 202 is equal to or greater than a predetermined threshold value, the wireless terminal device 202A changes the external network connection terminal from itself. It is determined that the wireless terminal device 202 should be switched (step S24).

  Next, the wireless terminal device 202A selects, for example, the wireless terminal device 202B having the maximum remaining battery level as a new external network connection terminal (step S25), and transmits a connection instruction to the wireless terminal device 202B (step S26). .

  Next, the wireless terminal device 202B receives a connection instruction from the wireless terminal device 202A, performs connection processing with the access point 101 as described later (step S27), and thereafter operates as an external network connection terminal.

  Next, the wireless terminal device 202A and the access point 101 perform a process of disconnecting communication connection with each other (step S28).

  FIG. 10 is a diagram showing an example of switching processing of the external network connection terminal in the wireless communication system according to the embodiment of the present invention.

  Referring to FIG. 10, first, the remaining battery level of wireless terminal device 202A, which is an external network connection terminal, is medium, the remaining battery level of wireless terminal device 202B is high, and the remaining battery level of wireless terminal device 202C is low. Consider a situation where the amount is medium. In this state, the wireless terminal device 202A maintains a state where it is an external network connection terminal because the difference between the remaining battery level and the remaining wireless terminal device 202 is small.

  Then, when the remaining battery level of the wireless terminal device 202A decreases to a low level, the wireless terminal device 202A selects the wireless terminal device 202B with the largest remaining battery level as a new external network connection terminal. The device 202B operates as an external network connection terminal.

  FIG. 11 is a diagram showing an exemplary sequence of connection processing (passive scan) between a wireless terminal device and an access point in the wireless communication system according to the embodiment of the present invention.

  Referring to FIG. 11, first, access point 101 transmits a beacon that is broadcast information. By this transmission, the ESSID (Extended Service Set Identifier) of the access point 101 included in the beacon is broadcast (step S31).

  The wireless terminal device 202 performs a beacon reception operation for a certain period of time, compares the ESSID included in the beacon with the ESSID set for itself, and searches for an access point that matches the ESSID set for itself (step S32). ).

  Next, when the access point 101 that matches the ESSID set for itself is found, the wireless terminal device 202 transmits authentication information (Authentication) to the access point 101 (step S33).

  Next, the access point 101 receives authentication information from the wireless terminal device 202, transmits ACK to the wireless terminal device 202 (step S34), and transmits authentication information to the wireless terminal device 202 (step S35).

  Next, the wireless terminal device 202 receives authentication information from the access point 101, transmits ACK to the access point 101 (step S36), and transmits a communication establishment request (Association Request) to the access point 101 (step S36). S37).

  Next, the access point 101 receives a communication establishment request from the wireless terminal device 202, transmits an ACK to the wireless terminal device 202 (step S38), and transmits a communication establishment response (Association Response) to the wireless terminal device 202. (Step S39).

  Next, the wireless terminal device 202 receives a communication establishment response from the access point 101 and transmits ACK to the access point 101 (step S40).

  When the communication connection between the wireless terminal device 202 and the access point 101 is established, the wireless terminal device 202 and the access point 101 start transmission / reception of data frames (step S41).

  FIG. 12 is a diagram showing an exemplary sequence of connection processing (active can) between a wireless terminal device and an access point in the wireless communication system according to the embodiment of the present invention.

  Referring to FIG. 12, first, access point 101 transmits a connection request when a beacon that is broadcast information cannot be received within a predetermined time (step S50). By this transmission, the ESSID set in the wireless terminal device 202 included in the connection request is broadcast as the ESSID that the wireless terminal device 202 desires to connect (step S51).

  Next, the access point 101 receives a connection request from the wireless terminal device 202, and when the ESSID included in the connection request matches its own ESSID, transmits a connection response to the wireless terminal device 202 (step S52).

  Next, when receiving a connection response from the access point 101, the wireless terminal device 202 transmits authentication information (Authentication) to the access point 101 (step S53).

  Next, the access point 101 receives authentication information from the wireless terminal device 202, transmits ACK to the wireless terminal device 202 (step S54), and transmits authentication information to the wireless terminal device 202 (step S55).

  Next, the wireless terminal device 202 receives the authentication information from the access point 101, transmits an ACK to the access point 101 (step S56), and transmits a communication establishment request (Association Request) to the access point 101 (step S56). S57).

  Next, the access point 101 receives a communication establishment request from the wireless terminal device 202, transmits an ACK to the wireless terminal device 202 (step S58), and transmits a communication establishment response (Association Response) to the wireless terminal device 202. (Step S59).

  Next, the wireless terminal device 202 receives a communication establishment response from the access point 101, and transmits ACK to the access point 101 (step S60).

  When the communication connection between the wireless terminal device 202 and the access point 101 is established, the wireless terminal device 202 and the access point 101 start transmission / reception of data frames (step S61).

[Modification]
In the above description, the wireless terminal device 202 is configured to determine whether to switch the external network connection terminal based on the comparison result between its own state and the state of the other wireless terminal device 202. However, the present invention is not limited thereto. Absent. The wireless terminal device 202 may be configured to determine whether to switch the external network connection terminal based on its own state without comparing with the state of the other wireless terminal device 202.

  That is, in the control unit 88 or the control unit 98, the state determination unit 13 determines whether the state of the network connection terminal satisfies a predetermined condition. Then, when the state determination unit 13 determines that the predetermined condition is satisfied, the terminal selection unit 14 newly selects a network connection terminal from the plurality of wireless terminal devices 202 in the ad hoc network 401.

  FIG. 13 is a diagram showing an exemplary sequence of a switching process of external network connection terminals in the wireless communication system according to the embodiment of the present invention.

  Referring to FIG. 13, in a state where wireless terminal apparatus 202A, which is an external network connection terminal, and access point 101 are communicating by transmitting and receiving wireless signals (step S81), first, wireless terminal apparatus 202A has its own Determine the radio wave condition. Specifically, for example, the wireless terminal device 202A switches the external network connection terminal from itself to another wireless terminal device 202 when the received power of the wireless signal from the access point 101 is less than a predetermined threshold. It is determined that it should be (step S82).

  Next, the wireless terminal device 202A follows a predetermined standard or randomly selects another wireless terminal device 202 in the ad hoc network 401, here, the wireless terminal device 202B as a new external network connection terminal (step S83). The connection instruction is transmitted to the wireless terminal device 202B (step S84).

  Next, the wireless terminal device 202B receives the connection instruction from the wireless terminal device 202A, performs the connection process with the access point 101 as described above (step S85), and thereafter operates as an external network connection terminal.

  Next, the wireless terminal device 202A and the access point 101 perform a process of disconnecting communication connection with each other (step S86).

  In the above description, the wireless terminal device 202 is configured to perform switching processing of the external network connection terminal. However, the present invention is not limited to this, and the access point 101 is configured to perform switching processing of the external network connection terminal. May be. Hereinafter, an operation in which the access point 101 performs the process of switching the external network connection terminal based on the radio wave state will be described as an example.

  FIG. 14 is a diagram showing an exemplary sequence of switching processing of external network connection terminals in the wireless communication system according to the embodiment of the present invention.

  Referring to FIG. 14, in a state where wireless terminal apparatus 202A, which is an external network connection terminal, and access point 101 are communicating by transmitting and receiving wireless signals (step S71), access point 101 first receives received radio wave information. The request is transmitted to the wireless terminal device 202A, and is transmitted to the wireless terminal device 202B via the wireless terminal device 202A. The access point 101 transmits a received radio wave information request periodically or when a predetermined condition is satisfied (step S72).

  Next, the wireless terminal device 202B receives the received radio wave information request from the access point 101 and, for example, receives the received radio wave information indicating the received power of the radio signal from the access point 101 via the wireless terminal device 202A. (Step S73). Although not shown in FIG. 14, for example, the access point 101 transmits a received radio wave information request to the radio terminal device 202 other than the radio terminal device 202B via the radio terminal device 202A, and acquires the received radio wave information.

  Next, the access point 101 determines the radio wave state of each wireless terminal device 202 based on the received radio wave information received from each wireless terminal device 202. Specifically, for example, when the access point 101 has a difference between the received power of the wireless signal from the access point 101 at the wireless terminal device 202A and the received power at the other wireless terminal device 202 is greater than or equal to a predetermined threshold. Then, it is determined that the external network connection terminal should be switched from the wireless terminal device 202A to another wireless terminal device 202 (step S74).

  Next, the access point 101 selects, for example, the wireless terminal device 202B having the maximum received power as a new external network connection terminal (step S75), and transmits a connection instruction to the wireless terminal device 202B via the wireless terminal device 202A. (Step S76).

  Next, the wireless terminal device 202B receives a connection instruction from the access point 101, performs connection processing with the access point 101 as described above (step S77), and thereafter operates as an external network connection terminal.

  Next, the wireless terminal device 202A and the access point 101 perform a process of disconnecting communication connection with each other (step S78).

  By the way, any one of a plurality of wireless terminal devices in an ad hoc network is set as an external network connection terminal, and the external network connection terminal is connected to a wireless base station device or an access point. When the external network connection terminal moves away from the radio base station apparatus or access point in the configuration for performing the communication, the radio wave condition between the external network connection terminal and the radio base station apparatus or access point deteriorates, Becomes unstable. Further, for example, the transmission power of the radio signal from the external network connection terminal to the radio base station apparatus or the access point increases, so that the power consumption of the external network connection terminal increases.

  On the other hand, in the wireless communication system according to the embodiment of the present invention, the state comparison unit 12 compares the state of the network connection terminal with the state of the other wireless terminal device 202. Then, the terminal selection unit 14 newly selects a network connection terminal from among the plurality of wireless terminal devices 202 in the ad hoc network 401 based on the comparison result by the state comparison unit 12.

  With such a configuration, the external network connection terminal can be switched when the state of the external network connection terminal becomes worse than the state of other wireless terminal devices. It is possible to maintain a good radio wave condition between them and stabilize communication. Further, it is possible to prevent the transmission power of the radio signal from the external network connection terminal to the access point 101 from increasing, and to prevent the power consumption of the external network connection terminal from increasing.

  Therefore, in the wireless communication system according to the embodiment of the present invention, communication between a wireless terminal device in a network in which a plurality of wireless terminal devices can perform wireless communication with each other and devices in other networks is improved. Can be done.

  In addition, when the state of the other wireless terminal device 202 is worse, for example, even if the state of the external network connection terminal is bad, the state of the other wireless terminal device 202 is worse even if the state of the external network connection terminal is bad. In addition, it is possible to prevent inappropriate switching of the external network connection terminal.

  In the wireless communication system according to the embodiment of the present invention, state determination unit 13 determines whether the state of the network connection terminal satisfies a predetermined condition. The terminal selection unit 14 selects a network connection terminal when the state determination unit 13 determines that the predetermined condition is satisfied.

  With such a configuration, it is possible to prevent the switching of the external network connection terminal when the state of the external network connection terminal is good to some extent. Therefore, the switching of the external network connection terminal frequently occurs and the communication becomes unstable. Can be prevented.

  In the radio communication system according to the embodiment of the present invention, the above state is a state of receiving radio waves from access point 101.

  With such a configuration, it is possible to appropriately select the wireless terminal device 202 having a good communication state with the access point 101 as an external network connection terminal.

  Further, in the wireless communication system according to the embodiment of the present invention, the state is a state of a battery in wireless terminal apparatus 202.

  With such a configuration, it is possible to prevent the wireless terminal device 202 from consuming power due to the operation as the external network connection terminal, and the battery of the specific wireless terminal device 202 is likely to run out. Communication in the ad hoc network 401 can be prevented. It can be continued stably.

  In the wireless communication system according to the embodiment of the present invention, state determination unit 13 determines whether the state of the network connection terminal satisfies a predetermined condition. Then, when the state determination unit 13 determines that the predetermined condition is satisfied, the terminal selection unit 14 newly selects a network connection terminal from the plurality of wireless terminal devices 202 in the ad hoc network 401.

  With such a configuration, the external network connection terminal can be switched when the state of the external network connection terminal is deteriorated, so that the radio wave condition between the external network connection terminal and the access point 101 is kept good and communication is performed. Can be stabilized. Further, it is possible to prevent the transmission power of the radio signal from the external network connection terminal to the access point 101 from increasing, and to prevent the power consumption of the external network connection terminal from increasing.

  In the wireless communication system according to the embodiment of the present invention, the external network connection terminal is selected based on the radio wave state or battery state of the wireless terminal device 202. However, the present invention is not limited to this. For example, the configuration may be such that an external network connection terminal is selected according to the communication priority, such as the type of application executed in the wireless terminal device 202. Further, for example, based on whether the wireless terminal device 202 selects a power saving mode in which a power saving operation is performed or a normal mode in which a power saving operation is not performed, specifically, the external mode in which the normal mode is selected. The configuration may be such that the network connection terminal is preferentially selected.

  Further, the wireless terminal device 202 or the access point 101 may be configured to select an external network connection terminal based on a combination of a radio wave state and a battery state of the wireless terminal device 202. Specifically, for example, the state comparison unit 12 converts the received power of the wireless signal from the access point 101 in the wireless terminal device 202 into an evaluation value, and converts the remaining battery level of the wireless terminal device 202 into an evaluation value. The total value of each evaluation value is calculated for each wireless terminal device 202 and compared. Then, the terminal selection unit 14 newly selects a network connection terminal from among the plurality of wireless terminal devices 202 in the ad hoc network 401 based on the comparison result of the total values of the wireless terminal devices 202 by the state comparison unit 12.

  In the wireless communication system according to the embodiment of the present invention, the state comparison unit may be configured to compare the state of all wireless terminal devices 202 in the ad hoc network 401 with the state of the external network connection terminal. The configuration may be such that the state of some of the wireless terminal devices 202 in the ad hoc network 401 is compared with the state of the external network connection terminal.

  In the wireless communication system according to the embodiment of the present invention, the access point 101 is provided as a relay device between the ad hoc network 401 and the IP network 402. However, the present invention is not limited to this. A configuration in which a femto base station is provided instead of the access point may be employed. A femto base station is defined as follows.

  In recent years, due to a dramatic increase in the number of subscribers of mobile communication services and an increase in the amount of communication traffic due to data communication, subscribers and communication traffic are distributed by forming smaller radius cells, and a certain level of communication It is desirable to provide speed to users in a stable manner. In addition, in order to deal with dead zones associated with the increase in the number of buildings, it is desired to install radio base station devices on the corporate floor and in ordinary households.

  Together with these demands, the processing capability of various devices used in the radio base station apparatus has been dramatically improved, and the miniaturization of the radio base station apparatus has progressed. Collecting.

  Since the radius of the femto cell (Femto Cell) formed by this small base station (hereinafter also referred to as a femto base station) is as small as about 10 meters, the femto base station is the macro cell (Macro Cell) formed by the macro base station. It may be used in places such as indoors and underground malls where it is out of service area and it is difficult to install macro base stations.

  The femtocell and access mode are described in 3GPP (Third Generation Partnership Project) SPEC TS 22.22 as follows. That is, a femto base station is a customer premises apparatus that connects a wireless terminal device connected via a wireless interface to a mobile communication carrier network using an IP backhaul.

  Further, in the femtocell access mode, the femto base station in the closed access mode provides a service only to related CSG (Closed Subscriber Group) members. The hybrid mode femto base station also provides services to the associated CSG members and CSG non-members. The femto base station in the open access mode operates as a normal base station.

  Such a 3GPP definition may also be applied to the wireless communication system according to the embodiment of the present invention.

  Further, the following definitions can be applied together with or separately from the above definitions.

  The macro base station and the pico base station are wireless base station devices that are under the management of the operator and can communicate with the wireless base station device that has contracted with the operator. Further, it is considered that the macro base station and the pico base station are basically not turned off.

  A femto base station is a radio base station apparatus that is installed mainly in an individual or corporate building and may move or be turned off depending on the circumstances of the user.

  Further, the femto base station operates in one of open / hybrid / closed access modes. When the femto base station operates in the closed access mode, only registered members (terminals) can be connected. When operating in the closed access mode, the service is provided only to registered members. When operating in the hybrid mode, the service is provided to both registered members and unregistered members, that is, non-members. When operating in the open access mode, the same operation as that of the macro base station and the pico base station is performed.

  The above embodiment should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

DESCRIPTION OF SYMBOLS 11 Terminal state acquisition part 12 State comparison part 13 State judgment part 14 Terminal selection part 81 Antenna 82 Circulator 83 Wireless reception part 84 Wireless transmission part 85 Signal processing part 86 Reception signal processing part 87 Transmission signal processing part 88 Control part 89 Input / output part DESCRIPTION OF SYMBOLS 91 Antenna 92 Circulator 93 Wireless receiving part 94 Wireless transmission part 95 Signal processing part 96 Reception signal processing part 97 Transmission signal processing part 98 Control part 101 Access point (wireless communication apparatus)
202, 202A, 202B, 202C, 202D Wireless terminal device 301 Wireless communication system

Claims (9)

A plurality of wireless terminal devices capable of performing wireless communication with each other;
By performing wireless communication with a connection terminal that is any one of the plurality of wireless terminal devices, transmission / reception is performed between devices other than the plurality of wireless terminal devices and the plurality of wireless terminal devices. A wireless communication system comprising a wireless communication device for relaying communication data,
A state comparison unit for comparing the state of the connection terminal and the state of the other wireless terminal device;
A wireless communication system comprising: a terminal selection unit for newly selecting the connection terminal from the plurality of wireless terminal devices based on a comparison result by the state comparison unit. The wireless communication system further includes:
A state determination unit for determining whether the state of the connection terminal satisfies a predetermined condition;
The wireless communication system according to claim 1, wherein the terminal selection unit selects the connection terminal when the state determination unit determines that the predetermined condition is satisfied.   The wireless communication system according to claim 1, wherein the state is a reception state of radio waves from the wireless communication device.   The wireless communication system according to any one of claims 1 to 3, wherein the state is a state of a battery. A plurality of wireless terminal devices capable of performing wireless communication with each other;
By performing wireless communication with a connection terminal that is any one of the plurality of wireless terminal devices, transmission / reception is performed between devices other than the plurality of wireless terminal devices and the plurality of wireless terminal devices. A wireless communication system comprising a wireless communication device for relaying communication data,
A state determination unit for determining whether the state of the connection terminal satisfies a predetermined condition;
A wireless communication system comprising: a terminal selection unit for newly selecting the connection terminal from the plurality of wireless terminal devices when the state determination unit determines that the predetermined condition is satisfied. By performing wireless communication with a connection terminal that is any one of a plurality of wireless terminal devices capable of performing wireless communication with each other, a device other than the plurality of wireless terminal devices and the plurality of wireless devices A wireless communication device for relaying communication data transmitted / received to / from a terminal device,
A state comparison unit for comparing the state of the connection terminal and the state of the other wireless terminal device;
A wireless communication device comprising: a terminal selection unit for newly selecting the connection terminal from the plurality of wireless terminal devices based on a comparison result by the state comparison unit. By performing wireless communication with a connection terminal that is any one of a plurality of wireless terminal devices capable of performing wireless communication with each other, a device other than the plurality of wireless terminal devices and the plurality of wireless devices A wireless communication device for relaying communication data transmitted / received to / from a terminal device,
A state determination unit for determining whether the state of the connection terminal satisfies a predetermined condition;
A wireless communication device comprising: a terminal selection unit for newly selecting the connection terminal from the plurality of wireless terminal devices when the state determination unit determines that the predetermined condition is satisfied. A plurality of wireless terminal devices capable of performing wireless communication with each other;
By performing wireless communication with a connection terminal that is any one of the plurality of wireless terminal devices, transmission / reception is performed between devices other than the plurality of wireless terminal devices and the plurality of wireless terminal devices. A communication control method in a wireless communication system comprising a wireless communication device for relaying communication data,
Comparing the state of the connected terminal with the state of the other wireless terminal device;
And a step of newly selecting the connection terminal from the plurality of wireless terminal devices based on the comparison result. A plurality of wireless terminal devices capable of performing wireless communication with each other;
By performing wireless communication with a connection terminal that is any one of the plurality of wireless terminal devices, transmission / reception is performed between devices other than the plurality of wireless terminal devices and the plurality of wireless terminal devices. A communication control method in a wireless communication system comprising a wireless communication device for relaying communication data,
Determining whether the state of the connected terminal satisfies a predetermined condition;
And a step of newly selecting the connection terminal from the plurality of wireless terminal devices when it is determined that the predetermined condition is satisfied.

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