WO2011155191A1 - 通信端末、制御装置、通信方法、制御方法、プログラム、及び集積回路 - Google Patents
通信端末、制御装置、通信方法、制御方法、プログラム、及び集積回路 Download PDFInfo
- Publication number
- WO2011155191A1 WO2011155191A1 PCT/JP2011/003226 JP2011003226W WO2011155191A1 WO 2011155191 A1 WO2011155191 A1 WO 2011155191A1 JP 2011003226 W JP2011003226 W JP 2011003226W WO 2011155191 A1 WO2011155191 A1 WO 2011155191A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- communication
- terminal
- frequency channel
- terminals
- unit
- Prior art date
Links
- 238000004891 communication Methods 0.000 title claims abstract description 428
- 238000000034 method Methods 0.000 title claims description 34
- 238000012790 confirmation Methods 0.000 claims abstract description 180
- 230000005540 biological transmission Effects 0.000 claims abstract description 142
- 238000001514 detection method Methods 0.000 claims abstract description 70
- 230000007274 generation of a signal involved in cell-cell signaling Effects 0.000 claims description 14
- 238000012545 processing Methods 0.000 abstract description 62
- 230000004044 response Effects 0.000 description 33
- 238000010586 diagram Methods 0.000 description 25
- 230000006870 function Effects 0.000 description 14
- 238000004590 computer program Methods 0.000 description 12
- 230000008859 change Effects 0.000 description 9
- 230000008569 process Effects 0.000 description 7
- 238000005516 engineering process Methods 0.000 description 5
- 101100172132 Mus musculus Eif3a gene Proteins 0.000 description 4
- 238000006243 chemical reaction Methods 0.000 description 4
- 230000010354 integration Effects 0.000 description 3
- 239000004065 semiconductor Substances 0.000 description 3
- 239000000470 constituent Substances 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 230000007423 decrease Effects 0.000 description 1
- 238000012544 monitoring process Methods 0.000 description 1
- 238000010187 selection method Methods 0.000 description 1
- 230000008054 signal transmission Effects 0.000 description 1
Images
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04W—WIRELESS COMMUNICATION NETWORKS
- H04W74/00—Wireless channel access
- H04W74/08—Non-scheduled access, e.g. ALOHA
- H04W74/0808—Non-scheduled access, e.g. ALOHA using carrier sensing, e.g. carrier sense multiple access [CSMA]
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04W—WIRELESS COMMUNICATION NETWORKS
- H04W72/00—Local resource management
- H04W72/02—Selection of wireless resources by user or terminal
Definitions
- the present invention relates to a method for avoiding packet collision caused by a hidden terminal problem in a wireless communication system.
- a control device also referred to as a “control station”
- a hidden terminal problem Such a problem caused by the inability to reach each other's signals is called a “hidden terminal problem”.
- FIG. 28 is a conceptual diagram for explaining the “hidden terminal problem”.
- each of the transmission terminal 30A and the transmission terminal 30B communicates with the reception terminal 40.
- the transmitting terminal 30A and the transmitting terminal 30B cannot detect the other party's signal by carrier sense and transmit signals to the receiving terminal 40 at the same time, and the signals collide with each other.
- Non-Patent Document 1 a control signal called RTS / CTS (Request to Send / Clear to Send) is sent to each of the transmission terminals 30A and 30B.
- RTS / CTS Request to Send / Clear to Send
- the transmitting terminal 30A transmits an RTS signal to the receiving terminal 40 before transmitting data.
- the receiving terminal 40 that has received the RTS signal transmits the CTS signal to the transmitting terminals 30A and 30B.
- the transmission terminal 30B enters a transmission standby state and stops signal transmission.
- the transmission terminal 30A that has received the CTS signal starts data transmission.
- the transmission terminal 30B is placed in a transmission standby state. Therefore, the signals transmitted from the transmission terminal 30A and the transmission terminal 30B are mutually transmitted. The probability of collision can be reduced.
- Patent Document 1 also discloses a technique for avoiding a hidden terminal problem without using RTS / CTS.
- the terminal in a communication system in which a terminal can be connected to a plurality of control devices, the terminal is connected to a control device with a low probability of occurrence of a hidden terminal problem among the plurality of control devices.
- the terminal scans the frequency channel of the control device 1 to measure the traffic statistics on the network and obtain the channel occupation rate. Next, the terminal also performs a similar scan on the frequency channel of the control device 2.
- control device 1 and the control device 2 calculate the channel usage rate of the terminal from the statistics of the traffic on the network obtained by scanning the frequency channel used by each, and use the calculated channel usage rate as the terminal Send to.
- the terminal selects a control device to be connected using the channel occupancy and channel utilization rate obtained in this way.
- the difference between the traffic amount scanned by the control device and the traffic amount scanned by the terminal is calculated.
- the terminal is connected to the control device that is determined to have the least number of hidden terminals.
- Non-Patent Document 1 the RTS / CTS signal becomes an overhead of data communication, and thus the throughput is lowered. In particular, when the data size is small, the influence of this overhead becomes significant.
- the present invention solves the above-described conventional problems, and provides a communication terminal, a control device, a communication method, and a control method that reduce the influence that occurs when grasping a hidden terminal even if the number of frequency channels increases. With the goal.
- a communication terminal includes a communication unit that transmits and receives a signal using one frequency channel selected from a plurality of frequency channels, and the control while sequentially switching the plurality of frequency channels.
- Wireless communication is performed by causing the communication unit to receive a notification signal indicating the number of other communication terminals that are performing wireless communication using the frequency channel.
- a second confirmation signal is detected for each frequency channel by causing the communication unit to receive a confirmation signal for each frequency channel confirmed by the received confirmation signal.
- the present invention is not only realized as an apparatus, but also an integrated circuit including processing means included in such an apparatus, a control method using the processing means constituting the apparatus as steps, or causing a computer to execute these steps. It can also be realized as a program.
- a terminal newly connected to the control device can reduce the probability that a hidden terminal problem will occur. Moreover, even if the number of frequency channels increases, it is possible to reduce the influence that occurs when grasping the hidden terminal.
- FIG. 1 is a configuration example of a radio communication system according to Embodiment 1 of the present invention.
- FIG. 2 is a functional block diagram of the communication terminal according to Embodiment 1 of the present invention.
- FIG. 3 is a functional block diagram of the control device according to Embodiment 1 of the present invention.
- FIG. 4A is a flowchart of processing performed by the newly connected terminal according to Embodiment 1 of the present invention.
- FIG. 4B is a flowchart of processing performed by the control device according to Embodiment 1 of the present invention.
- FIG. 4C is a flowchart of processing performed by the existing terminal according to Embodiment 1 of the present invention.
- FIG. 5 is a configuration example of a radio communication system according to Embodiment 2 of the present invention.
- FIG. 5 is a configuration example of a radio communication system according to Embodiment 2 of the present invention.
- FIG. 6 is a functional block diagram of a communication terminal according to Embodiment 2 of the present invention.
- FIG. 7A is a flowchart of processing performed by the newly connected terminal according to Embodiment 2 of the present invention.
- FIG. 7B is a flowchart of processing performed by the control device according to Embodiment 2 of the present invention.
- FIG. 7C is a flowchart of processing performed by an existing terminal according to Embodiment 2 of the present invention.
- FIG. 8 is a diagram showing an example of a connection sequence in the second embodiment of the present invention.
- FIG. 9 is a diagram showing the traffic volume of the hidden terminal of each frequency channel in the second embodiment of the present invention.
- FIG. 10 is a configuration example of a radio communication system according to Embodiment 3 of the present invention.
- FIG. 11 is a functional block diagram of a communication terminal according to Embodiment 3 of the present invention.
- FIG. 12 is a functional block diagram of the control device according to Embodiment 3 of the present invention.
- FIG. 13A is a flowchart of processing performed by a newly connected terminal according to Embodiment 3 of the present invention.
- FIG. 13B is a flowchart of processing performed by the control device according to Embodiment 3 of the present invention.
- FIG. 13C is a flowchart of processing performed by an existing terminal according to Embodiment 3 of the present invention.
- FIG. 14 is a diagram showing an example of a connection sequence according to Embodiment 3 of the present invention.
- FIG. 15 is a configuration example of a radio communication system according to Embodiment 4 of the present invention.
- FIG. 16 is a functional block diagram of a communication terminal according to Embodiment 4 of the present invention.
- FIG. 17 is a functional block diagram of a control device according to Embodiment 4 of the present invention.
- FIG. 18A is a flowchart of processing performed by a newly connected terminal according to Embodiment 4 of the present invention.
- FIG. 18B is a flowchart of processing performed by the control device in Embodiment 4 of the present invention.
- FIG. 18C is a flowchart of processing performed by an existing terminal according to Embodiment 4 of the present invention.
- FIG. 19 is a diagram showing an example of a connection sequence in the fourth embodiment of the present invention.
- FIG. 20 is a configuration example of a radio communication system according to the fifth embodiment of the present invention.
- FIG. 20 is a configuration example of a radio communication system according to the fifth embodiment of the present invention.
- FIG. 21 is a functional block diagram of a communication terminal according to Embodiment 5 of the present invention.
- FIG. 22 is a functional block diagram of a control device according to Embodiment 5 of the present invention.
- FIG. 23A is a flowchart of processing performed by a newly connected terminal according to Embodiment 5 of the present invention.
- FIG. 23B is a flowchart of processing performed by the control device in Embodiment 5 of the present invention.
- FIG. 23C is a flowchart of processing performed by an existing terminal according to Embodiment 5 of the present invention.
- FIG. 24 is a diagram showing an example of a connection sequence in the fifth embodiment of the present invention.
- FIG. 25 is a diagram illustrating an example when the transmission power of the confirmation packet is controlled according to the fifth embodiment of the present invention.
- FIG. 26 is a configuration example of a wireless communication system that is highly likely to be a hidden terminal according to Embodiment 5 of the present invention.
- FIG. 27 is an example of a wireless communication system in the case where terminals exist in each room in the home according to Embodiment 5 of the present invention.
- FIG. 28 is an example of a system configuration when a hidden terminal problem occurs.
- FIG. 29 is an example of a countermeasure against the hidden terminal problem when RTS / CTS described in Non-Patent Document 1 is used.
- FIG. 30 is an example of a process of selecting a control device for countermeasures against the hidden terminal problem described in Patent Document 1.
- a communication terminal controls a communication unit that transmits and receives a signal using one frequency channel selected from a plurality of frequency channels, and sequentially switches the plurality of frequency channels.
- Wireless communication is performed by causing the communication unit to receive a notification signal indicating the number of other communication terminals that are performing wireless communication using the frequency channel.
- a second confirmation signal is detected for each frequency channel by causing the communication unit to receive a confirmation signal for each frequency channel confirmed by the received confirmation signal.
- the number of communication terminals existing in a range where radio signals (radio waves) reach the terminal can be grasped for each frequency channel using the notification signal and the confirmation signal.
- the “confirmation signal” received by the communication terminal may be a signal that arrives directly from another communication terminal without being relayed by the control device or the like.
- the channel control unit includes the number of the other communication terminals detected by the first detection unit among the plurality of frequency channels, and the other communication terminal confirmed by the second detection unit.
- a frequency channel having the same number as the number may be selected, and the communication unit may transmit and receive signals to and from the control device.
- the channel control unit detects the number of the other communication terminals for each frequency channel with respect to the control device by the first detection unit, and then performs wireless communication using each frequency channel.
- a request signal for requesting transmission of a request signal for requesting transmission of the confirmation signal to the other communication terminal may be transmitted to the communication unit.
- the communication terminal causes the communication unit to receive a signal transmitted by the other communication terminal while the first detection unit detects the number of the other communication terminals for each frequency channel.
- a third detection unit that detects the number of transmission source terminals of the signal for each frequency channel may be provided.
- the channel control unit requests the control device to transmit the request signal in order from a frequency channel in which a difference between the number of communication terminals included in the notification signal and the number of transmission source terminals is small.
- the request signal to be transmitted may be transmitted to the communication unit.
- the presence of hidden terminals can be confirmed in order from the frequency channel where the possibility of the presence of hidden terminals is low. Since the processing can be stopped when a frequency channel in which no hidden terminal exists is found, the processing load is reduced.
- the communication terminal causes the communication unit to receive a signal transmitted by the other communication terminal while the first detection unit detects the number of the other communication terminals for each frequency channel.
- a third detection unit that detects information specifying the transmission source terminal of the signal for each frequency channel may be provided. Then, the channel control unit transmits the request signal for requesting the control device to transmit the request signal only to a communication terminal that cannot be detected by the third detection unit. You may let them.
- the communication terminal generates a request signal for requesting transmission of the confirmation signal to the other communication terminal that performs radio communication using the frequency channel while sequentially switching the plurality of frequency channels. And you may provide the signal generation part transmitted to the said communication part.
- the “request signal” received by the other communication terminal may be a signal that arrives directly from the communication terminal of the transmission source without being relayed by the control device or the like.
- the control device performs wireless communication with a communication terminal. Specifically, a communication unit that transmits and receives signals using one frequency channel selected from a plurality of frequency channels, and wireless communication using the frequency channel for each of the plurality of frequency channels. Wireless communication is performed using the frequency channel to a management unit that holds information of the communication terminal that is being performed and a communication terminal that is newly starting communication while sequentially switching the plurality of frequency channels.
- the first signal generation unit that generates a notification signal including the number of communication terminals that are present and transmits the notification signal to the communication unit, and performs wireless communication using the frequency channel while sequentially switching the plurality of frequency channels
- a request signal for requesting the communication terminal to transmit a confirmation signal to the communication terminal to newly start communication is generated and transmitted to the communication unit. That and a second signal generator.
- the number of terminals for each frequency channel can be notified to a terminal that is about to start communication, and a confirmation signal can be reliably transmitted to a communication terminal that is already communicating. Can do.
- a communication terminal that newly starts communication can select a frequency channel with the least number of hidden terminals.
- control device is a request signal for requesting transmission of the request signal to a communication terminal performing wireless communication using each frequency channel, from the communication terminal newly starting the wireless communication You may provide the channel control part which makes the said 2nd signal generation part produce
- the channel control unit causes the communication unit to receive the request signal including the number of communication terminals for each frequency channel that has already been confirmed by the communication terminal that is newly starting communication, and the plurality of frequencies Among the channels, the request signal is sent to the second signal generation unit in order from a frequency channel in which the difference between the number of communication terminals held in the management unit and the number of communication terminals included in the request signal is small. It may be generated.
- the channel control unit causes the communication unit to receive the request signal including information identifying a communication terminal that has already been confirmed by the communication terminal that is about to start communication, and starts the new communication.
- the second signal generator may generate the request signal that is transmitted only to the communication terminal for which the communication terminal to be confirmed cannot be confirmed.
- control device totals the communication volume of each communication terminal managed by the management unit at a predetermined time, and confirms with the communication terminal that is about to newly start communication among the plurality of frequency channels. You may make it select the frequency channel with little communication volume of the communication terminal which cannot receive a signal.
- the communication method is a method for performing wireless communication using a specific frequency channel. Specifically, the notification signal transmitted from the control device while sequentially switching a plurality of frequency channels, the notification signal indicating the number of other communication terminals performing wireless communication using the frequency channel By detecting the number of other communication terminals performing wireless communication for each frequency channel, and wireless communication using the frequency channel while sequentially switching the plurality of frequency channels.
- a confirmation signal detecting step for detecting, for each frequency channel, the number of other communication terminals confirmed by the received confirmation signal by receiving a confirmation signal transmitted from another communication terminal performing Among a plurality of frequency channels, the number of the other communication terminals detected in the terminal number detection step and before the confirmation in the confirmation signal detection step The difference between the number of other communication terminals to select the smallest frequency channel, and a communication step of transmitting and receiving signals to and from the control device.
- the control method is executed by a control device that performs wireless communication with a communication terminal. Specifically, for each of a plurality of frequency channels, a step of holding information of a communication terminal that performs wireless communication using the frequency channel, and newly starting communication while sequentially switching the plurality of frequency channels Transmitting a notification signal including the number of communication terminals performing wireless communication using the frequency channel to the communication terminal to be attempted, and switching the frequency channels while sequentially switching the frequency channels. And a step of transmitting a request signal for requesting transmission of a confirmation signal to a communication terminal that is newly starting communication, to a communication terminal that is performing wireless communication using.
- a program according to an embodiment of the present invention is a program that causes a computer to perform wireless communication. Specifically, it is a terminal number notification signal transmitted from the control device while sequentially switching a plurality of frequency channels, and indicates the number of other communication terminals performing wireless communication using the frequency channel
- a terminal number detection step of detecting the number of other communication terminals performing wireless communication for each frequency channel, and using the frequency channel while sequentially switching the plurality of frequency channels
- a confirmation signal detecting step for detecting, for each frequency channel, the number of other communication terminals confirmed by the received confirmation signal by receiving a confirmation signal transmitted from another communication terminal performing wireless communication;
- the number of the other communication terminals detected in the terminal number detection step among the plurality of frequency channels and the confirmation signal detection step are confirmed.
- the difference between the number of said other communication terminal selects the smallest frequency channel has, and a communication step of transmitting and receiving signals to and from the control device, causes the computer to execute.
- An integrated circuit is used in a communication terminal that performs wireless communication. Specifically, a communication unit that transmits and receives a signal using one frequency channel selected from among a plurality of frequency channels, and the controller transmits the signals while sequentially switching the plurality of frequency channels. A notification signal that indicates the number of other communication terminals that are performing wireless communication using the frequency channel is received by the communication unit, so that the other communication terminals that are performing wireless communication A first detection unit that detects the number for each frequency channel, and a confirmation signal transmitted from another communication terminal that performs wireless communication using the frequency channel while sequentially switching the plurality of frequency channels.
- a second detection unit that detects, for each frequency channel, the number of the other communication terminals confirmed by the received confirmation signal; Frequency channel having the smallest difference between the number of the other communication terminals detected by the first detection unit and the number of the other communication terminals confirmed by the second detection unit And a channel control unit that causes the communication unit to transmit and receive signals to and from the control device.
- FIG. 1 is a configuration example of a wireless communication system according to the first embodiment.
- control device 200 that controls a wireless network and terminals 100A to 100F that perform wireless communication with the control device 200 under the control of the control device 200.
- the control device 200 periodically transmits a beacon signal including wireless network control information in order to control the wireless network.
- Ch1 frequency channel 1
- Ch2 frequency channel 2
- the control device 200 switches the communication frequency channel between Ch1 and Ch2 at regular time intervals.
- the terminal 100B and the terminal 100C perform wireless communication with the control device 200 using Ch2, and the terminal 100D, the terminal 100E, and the terminal 100F use the existing connection terminal that performs wireless communication with the control device 200 using Ch1.
- existing terminal the terminal 100 ⁇ / b> A is a terminal to newly connect to the control device 200.
- FIG. 2 is a functional block diagram of communication terminal 100 in the first embodiment.
- the communication terminal 100 includes a reception unit 101, a data processing unit (second detection unit) 102, a confirmation packet generation unit 103, a selected channel notification generation unit 104, a transmission unit 105, and a beacon processing unit (first Detection section) 106 and a channel control section 110.
- the receiving unit 101 receives a radio signal from an external device (the control device 200 or another communication terminal; the same applies hereinafter).
- the receiving unit 101 demodulates the received radio signal and then converts the demodulated signal from an analog signal to a digital signal (hereinafter referred to as A / D conversion).
- the receiving unit 101 receives a request signal (confirmation packet transmission request) and a beacon signal (terminal number notification signal) from the control device 200.
- the receiving unit 101 also receives a confirmation signal (confirmation packet) from an existing terminal already connected to the control device 200.
- the transmission unit 105 converts the transmission signal generated by the confirmation packet generation unit 103 or the selected channel notification generation unit 104 from a digital signal to an analog signal (hereinafter referred to as D / A conversion). Then, the transmission unit 105 modulates the converted signal and transmits the modulated signal.
- the receiving unit 101 and the transmitting unit 105 constitute a communication unit.
- This communication unit transmits and receives signals to and from an external device using one frequency channel selected from among a plurality of frequency channels.
- the frequency channel used for communication is determined by the channel control unit 110 and notified to the control device 200.
- the data processing unit 102 detects the number of other communication terminals confirmed by the confirmation signal (confirmation packet) received by the receiving unit 101 for each frequency channel. In addition, the data processing unit 102 notifies the confirmation packet generation unit 103 that the reception unit 101 has received a request signal (confirmation packet transmission request).
- the beacon processing unit 106 determines the number of other communication terminals (number of connected terminals) that are performing wireless communication using the frequency channel. Detect for each frequency channel.
- the channel control unit 110 compares the number of connected terminals of each frequency channel acquired from the beacon signal with the number of connected terminals detected using the confirmation packet, thereby determining whether there is a hidden terminal and using it for communication. Select the frequency channel to be used.
- the selection channel notification generation unit 104 generates a packet (connection request, selection channel notification, etc.) for notifying the control device 200 of the selected frequency channel, and causes the transmission unit 105 to transmit the packet.
- the confirmation packet generation unit 103 generates a confirmation packet based on the confirmation packet transmission request notified from the data processing unit 102 and causes the transmission unit 105 to transmit the confirmation packet.
- FIG. 3 is a functional block diagram of the control device 200 in the first embodiment.
- the control device 200 includes a reception unit 201, a data processing unit 202, a management unit 203, a transmission request generation unit 204, a beacon generation unit 205, and a transmission unit 206.
- the reception unit 201 performs reception processing such as A / D conversion and demodulation in the same manner as the reception unit 101.
- the transmission unit 206 performs transmission processing such as D / A conversion and modulation in the same manner as the transmission unit 105.
- the reception unit 201 and the transmission unit 206 constitute a communication unit.
- the data processing unit 202 notifies the transmission request generation unit 204 that the reception unit 201 has received the request signal.
- the data processing unit 202 causes the transmission unit 206 to transmit a connection response to the connection request received by the reception unit 201, and transmits a selection channel response to the transmission unit 206 in response to the selection channel notification received by the reception unit 201.
- the management unit 203 manages information related to connection terminals of each frequency channel that can be used in the communication area. Specifically, the number of communication terminals performing wireless communication with the control device 200, information for identifying each communication terminal, and the like are held for each frequency channel.
- the transmission request generation unit 204 generates a transmission request for requesting each existing terminal to transmit a confirmation packet, and causes the transmission unit 206 to transmit the transmission request.
- the beacon generation unit 205 generates a beacon signal.
- a beacon signal is a signal indicating that a frequency channel capable of wireless communication has been switched. That is, the beacon signal is transmitted from the control device 200 at predetermined time intervals while sequentially switching the frequency channel.
- Each communication terminal monitors a beacon signal on a specific frequency channel, and recognizes that wireless communication is possible for a predetermined time from the time when the beacon signal is received.
- the beacon signal includes information indicating the number of communication terminals that are performing wireless communication using the frequency channel corresponding to the beacon signal. However, the information indicating the number of communication terminals is not necessarily included in the beacon signal, and may be transmitted as a signal different from the beacon signal.
- terminal 100A which is a new connection terminal, control apparatus 200, and terminals 100B to 100F, which are existing terminals, in Embodiment 1, will be described using FIGS. 4A to 4C, respectively.
- FIG. 4A to 4C are flowcharts showing processing of the terminal 100A, the control device 200, and the terminals 100B to 100F, respectively.
- the process of the terminal 100A which is a new connection terminal will be described.
- the terminal 100A trying to newly connect to the control device 200 performs a scan for receiving a beacon signal transmitted from the control device 200 (S101).
- the terminal 100A causes the receiving unit 101 to receive a beacon signal in each frequency channel while sequentially switching the frequency channels. Then, the beacon processing unit 106 refers to the received beacon signal, and acquires information indicating the number of existing terminals currently connected to the control device 200 using the frequency channel for each frequency channel.
- terminal 100A selects one of a plurality of frequency channels, and causes reception unit 101 to receive a confirmation packet transmitted from the existing terminal using the frequency channel (also referred to as “capture of existing terminal”). .
- the data processing unit 102 grasps the number of existing terminals in the frequency channel based on the number of captured confirmation packets (S102).
- the channel control unit 110 compares the number of existing terminals detected by capturing the confirmation packet with the number of existing terminals added to the beacon signal received through the corresponding frequency channel (S103).
- the terminal 100A newly starting connection in the frequency channel is determined. It can be determined that there is no hidden terminal.
- the terminal 100A determines to perform wireless communication with the control device 200 using the frequency channel. Then, the selected channel notification generation unit 104 causes the transmission unit 105 to transmit a selected channel notification that notifies the control device 200 of the selected frequency channel (S105).
- the terminal 100A when it is determined that the number of existing terminals acquired from the beacon signal is different from the number of existing terminals confirmed by the confirmation packet (NO in S103), the terminal 100A has a hidden terminal for the terminal 100A in the frequency channel. It is determined that it exists, and the frequency channel is changed (S104). Thereafter, the terminal 100A executes the processes of S102 and S103 on the changed frequency channel.
- control device 200 transmits a confirmation packet transmission request to, for example, an existing terminal already connected to the control device 200 using Ch1 (S106).
- control device 200 determines whether or not a selection channel notification transmitted when the frequency channel is selected from the terminal 100A that is about to start a connection has been received (S107).
- the data processing unit 202 of the control device 200 causes the transmitting unit 206 to transmit a selected channel response that is a response to the selected channel notification (S109).
- control device 200 changes the frequency channel to Ch2 (S108). Thereafter, the control device 200 executes the processes of S106 and S107 again with Ch2.
- the terminals 100B to 100F determine whether or not a request for transmitting a confirmation packet has been received from the control device 200 in the frequency channel used by each of the terminals 100B to 100F (S110).
- terminals 100B and 100C determine whether or not the transmission request is received by Ch2.
- terminals 100D to 100F determine whether or not a transmission request is received at Ch1.
- the terminals 100B to 100F receive confirmation packets for the terminal 100A to newly start connection to detect the existing terminals. Transmit (S111).
- confirmation packet generation unit 103 of the terminals 100B and 100C causes the transmission unit 105 to transmit a confirmation packet using Ch2.
- confirmation packet generation section 103 of terminals 100D to 100F causes transmission section 105 to transmit a confirmation packet using Ch1.
- the number of existing connected terminals that use each frequency channel for the beacon signal transmitted by the control device 200 is related. Add information.
- control device 200 transmits a confirmation packet so that the existing connection terminal can reliably communicate while the new connection terminal captures a packet transmitted from the existing connection terminal in the communication area.
- the terminal 100A newly connected to the control device 200 can recognize the existence of the hidden terminal and can reduce the possibility of the hidden terminal problem.
- a frequency channel in which no hidden terminal exists is selected from a plurality of frequency channels in the wireless communication system as shown in FIG. 1.
- the present invention is not limited to this.
- the present invention is effective even when a control device that does not have a hidden terminal is selected from a plurality of control devices.
- the confirmation packet may be only a preamble for signal synchronization in the physical layer, a network ID indicating which network is connected, and a terminal address.
- FIG. 5 is a configuration example of a radio communication system according to the second embodiment.
- control device 200 that controls a wireless network and a plurality of terminals 300A to 300F that perform wireless communication with the control device 200 under the control of the control device 200.
- FIG. 6 is a functional block diagram of communication terminal 300 in the second embodiment.
- Configurations of receiving section 101, transmitting section 105, beacon processing section 106, data processing section 102, confirmation packet generating section 103, and selected channel notification generating section 104 of communication terminal 300 in FIG. 6 are the same as those in the first embodiment. It is. An example of the details of channel control section 310 in Embodiment 2 is shown in FIG.
- the channel control unit 310 illustrated in FIG. 6 includes an acquisition unit 311, a capture unit (third detection unit) 312, a detection unit 313, and a selection unit 314.
- the acquisition unit 311 acquires the number of existing terminals connected to the control device 200 for each frequency channel based on the beacon signal.
- the capture unit 312 captures a packet (“confirmation packet” in the second embodiment) transmitted by an existing terminal existing in the communication area, and grasps the number of existing terminals that can reach the terminal.
- the detection unit 313 compares the actual number of existing terminals acquired from the acquisition unit 311 with the number of existing terminals that is the number of transmission source terminals of packets that can be captured by the capture unit 312. Detect the number of hidden terminals.
- the selection unit 314 selects a frequency channel to be connected based on the information regarding the hidden terminal obtained from the detection unit 313.
- terminal 300A as a new connection terminal, control device 200, and terminals 300B through 300F as existing terminals in Embodiment 2 will be described with reference to FIGS. 7A through 7C, respectively.
- FIGS. 7A to 7C are flowcharts showing processing of the terminal 300A, the control device 200, and the terminals 300B to 300F, respectively.
- the terminal 300A to newly connect to the control device 200 initializes the value of the frequency channel ch for scanning the beacon signal to init_scan_ch (S201).
- the terminal 300A performs a scan for receiving a beacon signal transmitted from the control device 200, and receives the beacon signal (S202).
- the terminal 300A acquires information Nch of the number of existing terminals currently connected to the control device 200 from the beacon signal received in S202 (S203).
- the terminal 300A sets the value of ch to next_scan_ch in order to change the frequency channel ch for scanning the beacon signal (S204).
- the terminal 300A determines whether the value of ch is last_scan_ch (S205). When it is determined that the value of ch is not last_scan_ch (NO in S205), the terminal 300A scans a beacon signal on the next frequency channel ch (S202).
- the terminal 300A determines that the beacon scan is completed, and transmits a connection request for requesting network connection to the control device 200. (S206).
- the terminal 300A determines that the connection is completed by receiving a connection response indicating that the connection is permitted from the control device 200 (S207).
- the terminal 300A initially sets the value of the frequency channel ch that captures an existing connection terminal already connected to the control device 200 to init_capture_ch (S208), and then captures a confirmation packet transmitted from the existing terminal. (S209).
- the terminal 300A acquires the existing terminal number Cch by capture (S210), and subtracts the Cch detected by capture from the connected terminal number Nch acquired from the beacon, so that the signal does not reach the terminal 300A. Hch is detected (S211).
- the terminal 300A sets the value of ch to next_capture_ch in order to change the frequency channel ch that captures the existing terminal (S212).
- the terminal 300A determines whether the value of ch is last_capture_ch (S213). When it is determined that the value of ch is not last_capture_ch (NO in S213), the terminal 300A captures an existing terminal on the next frequency channel ch (S209).
- ch is selected as a frequency channel ch for wireless communication with the control device 200 (S214).
- the terminal 300A transmits a selected channel notification for notifying the control apparatus 200 of the channel for performing the communication selected in S214 (S215).
- control device 200 receives a connection request transmitted from the terminal 300A that is about to start a new connection (S216).
- control device 200 transmits a connection response indicating permission of the connection request to the terminal 300A (S217).
- control device 200 initializes the value of the frequency channel ch for transmitting the confirmation packet transmission request to init_capture_ch (S218).
- the control device 200 transmits a confirmation packet transmission request for requesting an existing connection terminal to transmit a confirmation packet (S219).
- control device 200 sets the value of ch to next_capture_ch in order to change the frequency channel ch used for transmitting the confirmation packet transmission request (S220).
- control device 200 determines whether the value of ch is last_capture_ch (S221). When it is determined that the value of ch is not the last_capture_ch (NO in S221), the control device 200 transmits a confirmation packet transmission request on the next frequency channel ch (S219).
- the control device 200 determines that the capture of the existing terminal by the terminal 300A is completed, and responds to the selection channel notification transmitted from the terminal 300A.
- a selected channel response which is a response, is transmitted (S222).
- FIG. 8 is an example of a connection sequence when terminal 300A in Embodiment 2 of the present invention connects to control device 200.
- the connection sequence of the present invention includes a scan step and a capture step as main processes.
- the terminal 300A scans a beacon signal broadcast from the control device 200 at regular intervals.
- Each frequency channel is assigned a period (beacon interval) during which signals using the frequency channel can be transmitted and received. Therefore, the terminal 300A causes the reception unit 101 to receive a beacon signal while switching the frequency channel for each period.
- the terminal 300A transmits a connection request to the control device 200 after scanning the beacon signal of each frequency channel transmitted from the control device 200.
- This connection request is also a request signal for requesting the other communication terminals 300B to 300F performing wireless communication using each frequency channel to transmit a transmission request (request signal) of a confirmation packet.
- any one of a plurality of frequency channels may be arbitrarily selected.
- the frequency channel selected here is provisional, and may be different from the frequency channel finally determined according to the number of hidden terminals.
- the terminal 300A obtains information from the existing terminal information included in the beacon signal that three existing terminals are connected to Ch1 and two existing terminals are connected to Ch2.
- the control device 200 when receiving the connection request, transmits a connection response permitting connection to the terminal 300A.
- the terminal 300A detects a hidden terminal and selects a frequency channel that can reduce the influence of the hidden terminal problem.
- the control device 200 transmits a confirmation packet transmission request to the existing terminals 300D to 300F connected to Ch1.
- the control device 200 may broadcast a confirmation packet transmission request using Ch1.
- the existing connection terminals 300D to 300F Upon receiving a confirmation packet transmission request from the control device 200, the existing connection terminals 300D to 300F transmit confirmation packets. Each terminal 300D to 300F may broadcast a confirmation packet using, for example, Ch1.
- the terminal 300A captures the confirmation packet transmitted by the existing connection terminal using Ch1.
- the terminal 300A can capture the confirmation packets from the terminals 300E and 300F and cannot capture the confirmation packet from the terminal 300D regarding Ch1. Therefore, the terminal 300A can detect two existing connection terminals in Ch1.
- the control device 200 broadcasts a confirmation packet transmission request to the existing terminals 300B and 300C connected to Ch2, using Ch2.
- the existing connection terminals 300B and 300C broadcast the confirmation packet using Ch2.
- the terminal 300A captures the confirmation packet transmitted by the existing connection terminal using Ch2.
- the terminal 300A can capture confirmation packets from the terminals 300B and 300C regarding Ch2. Therefore, the terminal 300A can detect two existing connected terminals of Ch2.
- terminal 300A selects a frequency channel for communication based on information indicating the number of existing connected terminals included in the beacon signal and information indicating the number of existing connected terminals obtained by capture unit 312. To do.
- Ch1 information indicating the number of existing connection terminals included in the beacon signal is three, and information indicating the number of existing connection terminals obtained by the capture unit 312 is two. That is, the detection unit 313 determines that the number of hidden terminals in Ch1 is one.
- Ch2 information indicating the number of existing connection terminals included in the beacon signal is two, and information indicating the number of existing connection terminals obtained by the capture unit 312 is two. That is, the detection unit 313 determines that the number of hidden terminals in Ch2 is zero.
- the terminal 300A selects Ch2 as a frequency channel for communicating with the control device 200.
- the terminal 300A transmits a selection channel notification indicating that Ch2 is used as a frequency channel for communication to the control device 200.
- the control device 200 transmits a selection channel response to the terminal 300A as a response to the selection channel notification notified from the terminal 300A.
- the control device 200 transmits a confirmation packet transmission request to the terminals 300B to 300F, which are existing connection terminals, and the terminals 300B to 300F transmit the confirmation packet.
- the terminals 300B to 300F surely transmit confirmation packets, and the terminal 300A, which is a new connection terminal, can capture the number of existing connection terminals even in a wireless communication system in which access control is performed using CSMA / CA. .
- the terminal 300A can grasp the number of existing connected terminals.
- the new connection terminal can grasp the number of existing connection terminals that are transmission sources of signals reaching the terminal itself and the number of existing connection terminals that actually exist. Thereby, it becomes possible to recognize the frequency channel in which there is no hidden terminal, and the possibility of avoiding the hidden terminal problem can be improved.
- the detection time of the existing terminal can be shortened as compared with the method of measuring the frequency channel statistics. Furthermore, it is possible to prevent an increase in the detection time of an existing terminal even if the frequency channel capable of communication increases.
- FIG. 9 shows a frequency channel selection method when there are a plurality of frequency channels with the same minimum number of hidden terminals.
- the terminal 300D is a hidden terminal in Ch1
- the terminal 300C is a hidden terminal in Ch2.
- the terminal 300A selects a frequency channel with a small traffic volume of the hidden terminal.
- Ch1 terminal 300D determines that the amount of traffic is smaller, and Ch1 is selected.
- the control device 200 measures the traffic volume for each fixed time for each of the terminals 300B to 300F based on the signal volume transmitted / received to / from each of the terminals 300B to 300F.
- the terminal 300A uses information for identifying candidate frequency channels (Ch1, Ch2) and information for identifying hidden terminals (terminal 300D for Ch1 and terminal 300C for Ch2) in each frequency channel for selection channel notification. It is added and transmitted to the control device 200.
- control device 200 that has received such a selection channel notification compares the traffic volume of the terminal 300D and the terminal 300C added to the selection channel notification and selects Ch1 used by the terminal 300D with a small traffic volume. Thus, the terminal 300A is notified using the selected channel response.
- the traffic volume to be compared may be, for example, an average value, a maximum value, a total value, or the like of the traffic volume measured in the past certain time. Further, “within the past certain time period” may be, for example, the latest several beacon intervals.
- the transmission request for the confirmation packet in the present invention may be either a broadcast or unicast transmission method.
- each existing terminal may transmit autonomously distributed by CSMA / CA, but it transmits to each existing terminal by changing the TDMA (Time Division Multiple Access) or back-off time depending on the terminal. It is also possible to order. Thus, by changing the transmission timing of each existing terminal, it is possible to prevent a collision of confirmation packets between the existing terminals.
- CDMA Wideband Code Division Multiple Access
- FIG. 10 is a configuration example of a radio communication system according to Embodiment 3 of the present invention.
- the wireless communication system in FIG. 10 includes a control device 500 that controls a wireless network, and terminals 400A to 400F that perform wireless communication with the control device 500 under the control of the control device 500.
- the communication terminal further receives the signal transmitted by the other communication terminal in the communication unit while the first detection unit detects the number of other communication terminals for each frequency channel.
- a third detector that detects the number of transmission source terminals of the signal for each frequency channel. Then, the channel control unit sends a request signal for requesting the control device to transmit the request signal in order from a frequency channel in which the difference between the number of communication terminals included in the notification signal and the number of transmission source terminals is small. Send to the communication unit.
- the control device causes the communication unit to receive a request signal including the number of communication terminals for each frequency channel that has already been confirmed by a communication terminal that is about to start communication, and Among them, the second signal generation unit is caused to generate request signals in order from the frequency channel in which the difference between the number of communication terminals held in the management unit and the number of communication terminals included in the request signal is small.
- FIG. 11 is a functional block diagram of communication terminal 400 according to Embodiment 3 of the present invention.
- the same components as those in FIG. 6 are given the same reference numerals, and the descriptions of these components are omitted.
- the communication terminal 400 shown in FIG. 11 is different from the communication terminal 300 shown in FIG. 6 in that the functions of the capture unit 412 and the detection unit 413 are different and the number notification generation unit 407 is further provided.
- the capture unit 412 has a function of detecting an existing connection terminal while scanning a beacon signal in addition to the function of the capture unit 312 illustrated in FIG. Specifically, the capture unit 412 captures a packet transmitted by another communication terminal while scanning a beacon signal, and confirms a transmission source terminal of the packet.
- the content of the “packet transmitted by another communication terminal” may be anything, and the transmission destination may be anywhere. In other words, the capture unit 412 captures an arbitrary signal that is accidentally transmitted by another communication terminal, and confirms the presence of the communication terminal.
- the number notification generation unit 407 generates a connection request (request signal) including the number of existing connection terminals detected for each frequency channel by the capture unit 412 while scanning the beacon signal, and transmits the transmission unit 105. To send to.
- the detection unit 413 includes a timer for controlling the capture time of the confirmation packet in addition to the function of the detection unit 313 shown in FIG.
- FIG. 12 is a functional block diagram of the control device 500 according to Embodiment 3 of the present invention. 12, the same reference numerals are given to the same components as those in FIG. 3, and the description of these components is omitted.
- the transmission request generation unit 504 includes a timer that controls the time for the newly connected terminal to capture the confirmation packet in addition to the function of the transmission request generation unit 204 shown in FIG.
- the channel control unit 505 determines the order of frequency channels for transmitting the transmission request for the confirmation packet based on the notification of the number of captured terminals notified from the communication terminal 400.
- terminal 400A which is a new connection terminal according to Embodiment 3, control device 500, and terminals 400B to 400F, which are existing terminals, will be described with reference to FIGS. 13A to 13C.
- FIGS. 13A to 13C are flowcharts showing processing in the third embodiment of terminal 400A that is a new connection terminal, control device 500, and terminals 400B to 400F that are existing terminals, respectively.
- the terminal 400A newly connecting to the control device 500 initializes the value of the frequency channel ch for scanning the beacon signal to init_scan_ch (S301).
- the terminal 400A performs a scan for receiving a beacon signal transmitted from the control device 500, and receives the beacon signal (S302).
- the terminal 400A acquires the existing terminal number information Nch connected to the control device 500 using the current frequency channel (initscan_ch) from the beacon signal received in S302 (S303).
- the capture unit 412 of the terminal 400A captures a signal from an existing terminal while scanning the beacon signal from the control device 500, and stores the number of existing terminals that can be captured at the time of the scan (S304).
- the terminal 400A sets the value of ch to next_scan_ch in order to change the frequency channel ch for scanning the beacon signal (S305).
- the terminal 400A determines whether or not the value of ch is last_scan_ch (S306). When it is determined that the value of ch is not last_scan_ch (NO in S306), the terminal 400A performs a beacon scan on the next frequency channel ch (S302).
- the terminal 400A determines that the beacon scan has been completed, and transmits a connection request for requesting network connection to the control device 500 ( S307).
- the terminal 400A notifies the control device 500 of the number of existing terminals of each frequency channel stored in S304 (S308).
- the number of existing terminals confirmed in each frequency channel may be transmitted by being included in the connection request in S307, or may be transmitted as a signal different from the connection request.
- the terminal 400A receives a connection response indicating that the connection is permitted from the control device 500. Thereby, the connection with the control device 500 is completed (S309).
- the terminal 400A initializes the value of the frequency channel ch that captures the existing connection terminal already connected to the control device 500 to init_capture_ch (S310).
- the terminal 400A captures the confirmation packet transmitted from the existing connection terminal (S311). Note that the detection unit 413 starts timer monitoring for controlling the time for capturing the confirmation packet at the timing of starting the capture of the confirmation packet.
- the terminal 400A acquires the existing terminal number Cch by capture (S312).
- the terminal 400A detects the number Hch of hidden terminals that do not reach the terminal 400A by subtracting the Cch detected by the capture from the number Nch of connected terminals acquired from the beacon signal (S313).
- the terminal 400A determines whether or not the number of hidden terminals Hch is 0 (S314).
- the terminal 400A selects the current frequency channel ch as a frequency channel for communication (S315). Furthermore, the terminal 400A transmits a selection channel notification for notifying the control device 500 of the frequency channel selected in S315 (S320).
- the terminal 400A assumes that there is an existing terminal that has not yet been detected by the terminal 400A, and the capture time of the existing terminal in the frequency channel ch. It is determined whether or not has timed out (S316).
- the terminal 400A continues to capture the confirmation packet transmitted from the existing terminal (S311).
- the terminal 400A sets the value of ch to next_capture_ch in order to change the frequency channel ch for capturing the existing connection terminal. (S317).
- the terminal 400A determines whether or not the value of ch is last_capture_ch (S318). When it is determined that the value of ch is not last_capture_ch (NO in S318), the terminal 400A captures an existing terminal on the next frequency channel ch (S311). On the other hand, when it is determined that the value of ch is last_capture_ch (YES in S318), the terminal 400A determines that the capture of the existing terminal is completed, and communicates the frequency channel ch with the minimum number of hidden terminals Hch. The frequency channel to be selected is selected (S319).
- control device 500 receives a connection request transmitted from the terminal 400A (S321).
- control device 500 sets the confirmation packet so that the number of existing terminals that the terminal 400A has not yet captured is in the order of the frequency channels from the number of existing terminals already captured for each frequency channel notified from the terminal 400A.
- the order of the frequency channels for transmitting the transmission request is determined (S322).
- control device 500 transmits a connection response indicating permission of the connection request to the terminal 400A (S323).
- control device 500 initializes the value of the frequency channel ch for transmitting the confirmation packet transmission request to init_capture_ch (S324).
- control device 500 transmits a transmission request for requesting the existing terminal to transmit the confirmation packet (S325).
- control device 500 determines whether or not a selection channel notification from the terminal 400A has been received (S326). If it is determined that the selection channel notification has been received (YES in S326), control device 500 transmits a selection channel response that is a response to the selection channel notification transmitted from terminal 400A (S327).
- control device 500 determines whether the capture time of the existing terminal of terminal 400A has timed out for frequency channel ch ( S328). If it is determined that the capture time of the existing terminal remains (NO in S328), the control device 500 continues to monitor the selected channel notification (S326).
- control device 500 sets the value of ch to next_capture_ch in order to change the frequency channel ch for transmitting the confirmation packet transmission request. (S329).
- control device 500 determines whether or not the value of ch is last_capture_ch (S330). When it is determined that the value of ch is not the last_capture_ch (NO in S330), the control device 500 transmits a confirmation packet transmission request on the next frequency channel ch (S325).
- control device 500 determines that the capture of the existing terminal is completed, and proceeds to S327.
- FIG. 14 is an example of a connection sequence when terminal 400A in Embodiment 3 of the present invention connects to control device 500.
- the connection sequence of the present invention includes a scan step and a capture step.
- the terminal 400A scans a beacon signal transmitted from the control device 500 at regular intervals.
- the terminal 400A captures a signal from the existing terminal simultaneously with the beacon scan.
- the terminal 400A After scanning the beacon signal transmitted from the control device 500, the terminal 400A transmits a connection request to the control device 500 and the number of existing terminals that can be captured at the time of beacon scanning.
- the terminal 400A obtains information that three existing terminals are connected to Ch1 and two existing terminals are connected to Ch2 from the existing terminal information included in the beacon signal. Since signals from terminals 400C and 400D are received, one existing terminal of frequency channel Ch1 and one existing terminal of Ch2 have already been confirmed (captured).
- the control device 500 when receiving a connection request from the terminal 400A, transmits a connection response indicating that the terminal 400A is permitted to connect. In addition, the control device 500 issues a transmission request for a confirmation packet so that the number of existing terminals that the terminal 400A has not yet captured is in the order of frequency channels from the number of existing terminals that have been captured for each frequency channel notified from the terminal 400A. Determine the order of frequency channels to be transmitted.
- the control apparatus 500 switches the frequency channel which transmits the transmission request
- a hidden terminal is detected, and a frequency channel that can reduce the influence of the hidden terminal problem is selected.
- the control device 500 transmits a confirmation packet transmission request to the existing terminals 400B and 400C connected to Ch2.
- the terminals 400B and 400C transmit the confirmation packet.
- the terminal 400A captures the confirmation packet transmitted by the existing terminal using Ch2.
- the terminal 400A can capture confirmation packets from the existing terminals 400B and 400C using Ch2. That is, the terminal 400A can detect two existing connected terminals of Ch2.
- the terminal 400 ⁇ / b> A determines that all the existing terminals of Ch ⁇ b> 2 have been captured, and performs a frequency channel for communication Ch2 is selected.
- the terminal 400A transmits the selected channel notification to the control device 500 as a frequency channel for communicating Ch2.
- the control device 500 transmits a selection channel response to the terminal 400A as a response to the information notified from the terminal 400A.
- the newly connected terminal also captures the signal transmitted by the existing terminal during the beacon scan.
- the capture time of the existing terminal can be shortened.
- the order of frequency channels at the time of capture of existing terminals is set in the order of few existing terminals that are not captured by the new connection terminal, but this is not a limitation.
- the order of frequency channels to be captured may be determined according to frequency channel conditions such as signal power, interference power, or the number of accommodated terminals.
- the signal power can be measured by a beacon, a connection request, a connection response, or the like.
- the control device 500 can also grasp the interference amount of each frequency channel or the number of accommodated terminals.
- FIG. 15 is a configuration example of a radio communication system according to Embodiment 4 of the present invention.
- control device 700 that controls a wireless network and terminals 600A to 600F that perform wireless communication with the control device 700 under the control of the control device 700.
- the communication terminal according to Embodiment 4 further receives the signal transmitted by the other communication terminal in the communication unit while the first detection unit detects the number of other communication terminals for each frequency channel.
- a third detection unit that detects information for specifying the transmission source terminal of the signal for each frequency channel is provided.
- the channel control unit causes the communication unit to transmit a request signal that requests the control device to transmit the request signal only to the communication terminal that could not be detected by the third detection unit.
- FIG. 16 is a functional block diagram of communication terminal 600 according to Embodiment 4 of the present invention.
- FIG. 16 the same components as those in FIG. 11 are given the same reference numerals, and the description of these components is omitted.
- the communication terminal 600 further includes an address storage unit 607 and a generation unit 608.
- the address storage unit 607 stores the address (information identifying the existing terminal) of the existing terminal that can be captured while the capture unit 412 scans the beacon signal.
- the generation unit 608 causes the transmission unit 105 to transmit the existing terminal address notification including the address of the captured existing terminal stored in the address storage unit 607 to the control device 500.
- the control device further causes the communication unit to receive a request signal including information specifying a communication terminal that has already been confirmed by a communication terminal that is about to start communication, and newly starts communication.
- a channel control unit is provided that causes the second signal generation unit to generate a request signal that is transmitted only to the communication terminal for which the communication terminal to be confirmed cannot be confirmed.
- FIG. 17 is a functional block diagram of the control device 700 according to the fourth embodiment of the present invention.
- control device 700 further includes a control unit 705.
- the control unit 705 determines the order of the terminal and the frequency channel that transmit the transmission request for the confirmation packet based on the address notification of the existing captured terminal notified from the communication terminal 600.
- terminal 600A which is a newly connected terminal, control apparatus 700, and terminals 600B to 600F, which are existing terminals, in Embodiment 4 will be described using FIGS. 18A to 18C, respectively.
- FIGS. 18A to 18C are flowcharts showing processing of terminal 600A which is a new connection terminal, control apparatus 700, and terminals 600B to 600F which are existing terminals in the fourth embodiment.
- the terminal 600A to be newly connected to the control device 700 initializes the value of the frequency channel ch for scanning the beacon signal to init_scan_ch (S401).
- the terminal 600A performs a scan for receiving a beacon signal transmitted from the control device 700, and receives the beacon signal (S402).
- the terminal 600A acquires the existing terminal number information Nch currently connected to the control device 700 from the beacon signal received in S402 (S403).
- the terminal 600A captures a signal from an existing terminal while scanning the beacon signal from the control device 700, and stores the number of existing terminals Sch that can be captured at the time of the scan and the address of the terminal (S404). ).
- the terminal 600A sets the value of ch to next_scan_ch in order to change the frequency channel ch for scanning the beacon signal (S405).
- the terminal 600A determines whether or not the value of ch is last_scan_ch (S406). When it is determined that the value of ch is not last_scan_ch (NO in S406), the terminal 600A performs a beacon scan on the next frequency channel ch (S402).
- the terminal 600A determines that the beacon scan is completed, and transmits a connection request for requesting network connection to the control device 700 (S407). ).
- the terminal 600A notifies the control device 700 of the address of the existing terminal that has been captured for each frequency channel stored in S404 (S408). This notification may be included in the connection request in S407 or may be transmitted as another signal.
- the terminal 600A receives the connection response indicating that the connection is permitted from the control device 700, thereby completing the connection (S409).
- the terminal 600A initializes the value of the frequency channel ch that captures the existing terminal already connected to the control device 700 to init_capture_ch (S410).
- the terminal 600A captures the confirmation packet transmitted from the existing terminal (S411).
- the terminal 600A acquires the existing terminal number Cch by capture (S412).
- the terminal 600A subtracts the existing terminal number Cch obtained when capturing the existing terminal from the connected terminal number Nch acquired from the beacon signal and the existing terminal number Sch captured during the beacon scan, thereby The number Hch of hidden terminals that do not reach the signal up to 600 A is detected (S 413).
- the terminal 600A determines whether or not the number of hidden terminals Hch is 0 (S414). When it is determined that the number of hidden terminals Hch is 0 (YES in S414), the terminal 600A selects the frequency channel ch as a frequency channel for communication (S415). Then, the terminal 600A causes the transmission unit 105 to transmit a selection channel notification for notifying the control device 700 of the frequency channel selected in S415 (S420).
- the terminal 600A assumes that there is an existing terminal that has not yet been detected by the terminal 600A, and the capture time of the existing terminal in the frequency channel ch. It is determined whether or not has timed out (S416). If it is determined that the capture time of the existing terminal remains (NO in S416), the terminal 600A proceeds to S411.
- the terminal 600A sets the value of ch to next_capture_ch in order to change the frequency channel ch for capturing the existing terminal (S417). ).
- the terminal 600A determines whether or not the value of ch is last_capture_ch (S418). If it is determined that the value of ch is not last_capture_ch (NO in S418), the terminal 600A captures an existing terminal on the next frequency channel ch (S411).
- the terminal 600A determines that the capture of the existing terminal is completed, and communicates the frequency channel ch that minimizes the number of hidden terminals Hch.
- the frequency channel ch is selected (S419).
- control device 700 receives a connection request transmitted from the terminal 600A (S421).
- control device 700 transmits confirmation packet transmission requests in order of frequency channels in which the number of existing terminals that the terminal 600A has not yet captured is smaller than the number of existing terminals that have been captured for each frequency channel notified from the terminal 600A.
- the order of frequency channels is determined (S422).
- control device 700 transmits a connection response indicating permission of the connection request to the terminal 600A (S423).
- control device 700 initializes the value of the frequency channel ch for transmitting the confirmation packet transmission request to init_capture_ch (S424).
- the control device 700 transmits a transmission request only to an existing terminal that has not yet been captured by the newly connected terminal (S425).
- control device 700 determines whether or not a selection channel notification from the terminal 600A has been received (S426). If it is determined that the selection channel notification is received (YES in S426), control device 700 transmits a selection channel response that is a response to the selection channel notification transmitted from terminal 600A (S427).
- control device 700 determines whether or not the existing terminal capture time by terminal 600A has timed out for frequency channel ch. (S428). When it is determined that the capture time of the existing terminal remains (NO in S428), the control device 700 continues to monitor the selected channel notification (S426).
- control device 700 sets the value of ch to next_capture_ch in order to change the frequency channel ch for transmitting the confirmation packet transmission request. (S429).
- control device 700 determines whether or not the value of ch is last_capture_ch (S430). When it is determined that the value of ch is not the last_capture_ch (NO in S430), the control device 700 transmits a confirmation packet transmission request on the next frequency channel ch (S425).
- control device 700 determines that the capture of the existing terminal is completed, and proceeds to S427.
- FIG. 19 is an example of a connection sequence when terminal 600A in Embodiment 4 of the present invention connects to control device 700.
- the connection sequence of the present invention includes a scan step and a capture step.
- the terminal 600A scans a beacon signal transmitted from the control device 700 at regular intervals. Simultaneously with the beacon scan, the terminal 600A captures a signal from the existing terminal.
- the terminal 600A After scanning the beacon signal transmitted from the control device 700, the terminal 600A transmits a connection request and an address notification of an existing terminal that can be captured at the time of beacon scanning to the control device 700.
- terminal 600A obtains information that three existing terminals are connected to Ch1 and two existing terminals are connected to Ch2 from existing terminal information included in the beacon signal.
- the addresses of the terminals 600C and 600D are transmitted to the control device 700.
- the control device 700 transmits a connection response indicating that the connection is permitted to the terminal 600A.
- control device 700 transmits confirmation packet transmission requests in the order of frequency channels in which the number of existing terminals that the terminal 600A has not yet captured is smaller than the number of existing terminals that have been captured for each frequency channel notified from the terminal 600A. Determine the order of frequency channels to be used.
- terminal 600A since terminal 600A has already captured one existing terminal (600D) for frequency channel Ch1 and one existing terminal (600C) for Ch2, there are two uncaptured existing terminals in Ch1 and one in Ch1. It becomes. Therefore, the control device 700 switches the frequency channel for transmitting the confirmation packet transmission request in the order of Ch2 and Ch1.
- a hidden terminal is detected, and a frequency channel that can reduce the influence of the hidden terminal problem is selected.
- the control device 700 transmits a confirmation packet transmission request to the existing terminal connected to Ch2.
- the control device 700 transmits a confirmation packet transmission request only to the existing terminal 600B.
- the existing connection terminal 600B transmits the confirmation packet.
- the terminal 600A captures the confirmation packet transmitted by the existing terminal using Ch2.
- the terminal 600A can capture the confirmation packet from the terminal 600B using Ch2. That is, the terminal 600A can detect two existing connected terminals of Ch2.
- terminal 600A determines that all the existing terminals of Ch2 have been captured based on the information on the number of existing terminals included in the beacon signal and the information obtained by packet capture of the existing terminals, and the frequency at which communication is performed Ch2 is selected as the channel.
- the terminal 600A transmits to the control device 700 a notification of a selected channel that uses Ch2 as a frequency channel for communication.
- Control device 700 transmits a selected channel response to terminal 600A as a response to the selected channel notification transmitted from terminal 600A.
- the new connection terminal also captures the signal transmitted by the existing terminal during the beacon scan, and the address of the existing terminal that has already been captured. To the control device. As a result, it is possible to transmit a transmission request for a confirmation packet only to an existing terminal that has not been scanned by a new connection terminal. As a result, traffic due to transmission / reception of confirmation packets is reduced, and the capture time of an existing terminal can be shortened.
- Embodiment 5 The communication terminal according to Embodiment 5 further requests a request signal for requesting transmission of a confirmation signal to another communication terminal that performs radio communication using the frequency channel while sequentially switching a plurality of frequency channels. Is provided with a request signal generation unit that causes the communication unit to transmit.
- FIG. 20 is a configuration example of a wireless communication system according to the fifth embodiment of the present invention.
- the wireless communication system in FIG. 20 includes a control device 900 that controls a wireless network and terminals 800A to 800F that perform wireless communication with the control device 900 under the control of the control device 900.
- the configuration of terminals 800A to 800F is the same as that of communication terminal 800 shown in FIG.
- the communication terminal according to Embodiment 5 further requests a request signal for requesting transmission of a confirmation signal to another communication terminal that performs radio communication using the frequency channel while sequentially switching a plurality of frequency channels. Is generated, and a signal generation unit is transmitted to the communication unit.
- FIG. 21 is a functional block diagram of communication terminal 800 according to Embodiment 5 of the present invention.
- the communication terminal 800 further includes a transmission request generation unit (signal generation unit) 807.
- the transmission request generation unit 807 generates a request signal for requesting another communication terminal to transmit a confirmation signal, and causes the transmission unit 105 to transmit the request signal.
- FIG. 22 is a functional block diagram of the control device 900 according to the fifth embodiment of the present invention.
- terminal 800A as a new connection terminal
- control apparatus 900 processing performed by terminal 800A as a new connection terminal
- terminals 800B through 800F as existing connection terminals in Embodiment 5 will be described with reference to FIGS. 23A through 23C.
- FIGS. 23A to 23C are flowcharts showing processing of terminal 800A which is a new connection terminal, control apparatus 900, and terminals 800B to 800F which are existing connection terminals in the fifth embodiment.
- the terminal 800A to be newly connected to the control device 900 performs a scan for receiving a beacon signal transmitted from the control device 900, and an existing connection currently connected to the control device 900 from the received beacon signal. Terminal number information is acquired (S501).
- the terminal 800A transmits a confirmation packet transmission request to the existing terminal (S502).
- the terminal 800A captures the confirmation packet transmitted from the existing terminal, and grasps the number of existing terminals from the number of captured confirmation packets (S503).
- the terminal 800A compares the number of existing connected terminals added to the beacon signal with the number of existing connected terminals detected from the confirmation packet, and determines whether there is a hidden terminal (S504).
- the terminal 800A determines that communication is performed on the frequency channel, and selects to notify the control device 900 of the selected frequency channel A channel notification is transmitted (S506).
- the terminal 800A determines that there is a hidden terminal and changes the frequency channel (S505).
- the control device 900 determines whether or not a selection channel notification has been received (S507). If it is determined that the selected channel notification has been received (YES in S507), the control device 900 transmits a selected channel response that is a response to the selected channel notification (S509). On the other hand, when determining that the notification of the selected channel has not been received (NO in S507), the control device 500 changes the frequency channel (S508).
- FIG. 24 is an example of a sequence when terminal 800A in Embodiment 5 of the present invention connects to control device 900.
- the sequence of the present invention includes a scanning step and an already captured step.
- the terminal 800A scans a beacon signal transmitted from the control device 900 at regular intervals.
- the terminal 800A transmits a connection request to the control device 900 after scanning the beacon signal transmitted from the control device 900.
- the control device 900 when receiving the connection request, transmits a connection response indicating that the connection is permitted to the terminal 800A.
- a hidden terminal is detected and a frequency channel that can reduce the influence of the hidden terminal problem is selected.
- the terminal 800A broadcasts a confirmation packet transmission request to Ch1.
- an existing terminal connected to Ch1 When an existing terminal connected to Ch1 receives a confirmation packet transmission request, it transmits the confirmation packet.
- the transmission request transmitted by the terminal 800A reaches the terminals 800D and 800E, but does not reach the terminal 800F. Therefore, only terminals 800D and 800E transmit confirmation packets.
- terminal 800A captures the confirmation packet transmitted by the existing terminal using Ch1.
- terminal 800A captures packets transmitted from two existing terminals connected to Ch1.
- the terminal 800A since the information on the number of existing terminals included in the beacon signal is three and the information obtained by capturing packets transmitted from the existing terminals is two, the terminal 800A has 1 hidden terminal in Ch1. It is determined that there is a base, and the next frequency channel (Ch2) is shifted to.
- the terminal 800A broadcasts a confirmation packet transmission request to Ch2.
- an existing terminal connected to Ch2 When an existing terminal connected to Ch2 receives a confirmation packet transmission request, it transmits the confirmation packet.
- the transmission request transmitted by the terminal 800A has reached the terminals 800B and 800C. Accordingly, terminals 800B and 800C transmit confirmation packets.
- the terminal 800A captures the confirmation packet transmitted by the existing terminal using Ch2.
- a terminal 800A captures a packet transmitted by two existing terminals connected to Ch2.
- Ch2 is selected as a frequency channel for communication.
- the terminal 800A transmits notification information of a selected channel indicating that the channel is a frequency channel using Ch2 to the control device 900.
- the control device 900 transmits a selection channel response to the terminal 800A as a response to the notification information of the selection channel transmitted from the terminal 800A.
- the confirmation packet transmission request is transmitted to the existing terminal serving as the hidden terminal by transmitting the confirmation packet transmission request from the newly connected terminal. Will not reach. As a result, the number of terminals that transmit confirmation packets is reduced, so that transmission / reception traffic is reduced and collisions between confirmation packets transmitted by a plurality of existing terminals can be reduced.
- control device does not transmit the confirmation packet, and the control device can be provided with a confirmation packet transmission request generation unit in the new connection terminal. It can be implemented without significant changes in configuration.
- FIG. 25 shows a case where the transmission power when terminal 1000A, which is a new connection terminal, transmits a confirmation packet transmission request is limited to reach the control apparatus 900.
- the terminal 1000A is different in the function of the detection unit 413 from the communication terminal 800 in FIG.
- the detection unit of the terminal 1000A has a function of calculating the ratio between the number of existing terminals included in the beacon signal and the number of existing terminals captured by the confirmation packet.
- the confirmation packet is transmitted only from the terminals 800B and 800E by controlling the transmission power of the transmission request for the confirmation packet.
- the terminal 1000A calculates, for each frequency channel, the ratio between the number of existing terminals included in the beacon signal and the number of existing terminals captured by the confirmation packet, and the frequency channel having a high ratio of existing terminals that can be captured. Select.
- control device 900 When the control device 900 knows the network topology such as the positional relationship between the terminals 1000A and 800B to 800F, it determines an existing terminal that is likely to be a hidden terminal for the terminal 1000A that is a new connection terminal. It becomes possible. For this reason, it is also possible to transmit confirmation packet transmission requests in order from existing terminals that are likely to be hidden terminals.
- the terminal 10F when the terminal 10A communicates with the control device 20, the terminal most likely to be a hidden terminal is the terminal 10F. More specifically, the terminal 10F existing on the straight extension line connecting the terminal 10A and the control device 20 is likely to be a hidden terminal with respect to the terminal 10A.
- the terminal 10A may transmit a confirmation packet only from the terminal 10F. If the terminal 10A can confirm the arrival of the confirmation packet from the terminal 10F, it can confirm that other terminals cannot simultaneously become hidden terminals.
- the propagation loss due to the wall is much larger than the propagation loss due to space, so the propagation status between each terminal in the room partitioned by the wall as shown in FIG. There is a correlation. For this reason, the transmission request for the confirmation packet may be transmitted to only one of the existing terminals in each room.
- a frequency channel is assigned to each room, it is possible to automatically register in which room the home appliance equipped with the wireless device is located when the home appliance is connected to the network. Further, since the frequency channels are different, it is easy to multicast a signal only to a specific room when it is desired to activate only the home appliances in the specific room at the same time.
- the present invention is not limited to this.
- another network using a plurality of frequency channels such as PLC (Power Line Communications) may be used.
- each of the above-described embodiments may be realized by an LSI (Large Scale Integration) that is typically an integrated circuit. These may be individually made into one chip, or may be made into one chip so as to include all or part of the structure.
- An integrated circuit may be referred to as an IC, a system LSI, a super LSI, an ultra LSI, or the like depending on the degree of integration.
- the method of the integrated circuit is not limited to the LSI, and may be realized using a dedicated circuit or a general-purpose processor.
- an FPGA Field Programmable Gate Array
- reconfigurable processor capable of reconfiguring connection and setting of circuit cells inside the LSI may be used.
- Each of the above devices is specifically a computer system including a microprocessor, ROM, RAM, a hard disk unit, a display unit, a keyboard, a mouse, and the like.
- a computer program is stored in the RAM or the hard disk unit.
- Each device achieves its functions by the microprocessor operating according to the computer program.
- the computer program is configured by combining a plurality of instruction codes indicating instructions for the computer in order to achieve a predetermined function.
- the system LSI is a super multifunctional LSI manufactured by integrating a plurality of components on one chip, and specifically, a computer system including a microprocessor, a ROM, a RAM, and the like. .
- a computer program is stored in the RAM.
- the system LSI achieves its functions by the microprocessor operating according to the computer program.
- the constituent elements constituting each of the above devices may be constituted by an IC card or a single module that can be attached to and detached from each device.
- the IC card or module is a computer system that includes a microprocessor, ROM, RAM, and the like.
- the IC card or the module may include the super multifunctional LSI described above.
- the IC card or the module achieves its functions by the microprocessor operating according to the computer program. This IC card or this module may have tamper resistance.
- the present invention may be the method described above. Further, the present invention may be a computer program that realizes these methods by a computer, or may be a digital signal composed of a computer program.
- the present invention also relates to a computer-readable recording medium capable of reading a computer program or a digital signal, such as a flexible disk, hard disk, CD-ROM, MO, DVD, DVD-ROM, DVD-RAM, BD (Blu-ray Disc), It may be recorded in a semiconductor memory or the like. Further, it may be a digital signal recorded on these recording media.
- a computer-readable recording medium capable of reading a computer program or a digital signal, such as a flexible disk, hard disk, CD-ROM, MO, DVD, DVD-ROM, DVD-RAM, BD (Blu-ray Disc), It may be recorded in a semiconductor memory or the like. Further, it may be a digital signal recorded on these recording media.
- the present invention may transmit a computer program or a digital signal via an electric communication line, a wireless or wired communication line, a network represented by the Internet, a data broadcast, or the like.
- the present invention may be a computer system including a microprocessor and a memory.
- the memory may store the computer program, and the microprocessor may operate according to the computer program.
- program or digital signal may be recorded on a recording medium and transferred, or the program or digital signal may be transferred via a network or the like, and may be implemented by another independent computer system.
- the radio communication system according to the present invention is useful for radio communication for selecting a frequency channel or a control device for communication from a plurality of frequency channels or a plurality of control devices.
Landscapes
- Engineering & Computer Science (AREA)
- Computer Networks & Wireless Communication (AREA)
- Signal Processing (AREA)
- Mobile Radio Communication Systems (AREA)
Abstract
Description
図1は、実施の形態1における無線通信システムの構成例である。
図5は、実施の形態2における無線通信システムの構成例である。
図10は、本発明の実施の形態3における無線通信システムの構成例である。
図15は、本発明の実施の形態4における無線通信システムの構成例である。
実施の形態5に係る通信端末は、さらに、複数の周波数チャネルを順次切り替えながら、当該周波数チャネルを使用して無線通信を行っている他の通信端末に確認信号の送信を要求するための要求信号を、通信部に送信させる要求信号生成部を備える。
なお、本発明を上記実施の形態に基づいて説明してきたが、本発明は、上記の実施の形態に限定されないのはもちろんである。以下のような場合も本発明に含まれる。
10A,10B,10C,10D,10E,10F,100A,100B,100C,100D,100E,100F,300A,300B,300C,300D,300E,300F,400A,400B,400C,400D,400E,400F,600A,600B,600C,600D,600E,600F,800A,800B,800C,800D,800E,800F,1000A 端末
30A,30B 送信端末
40 受信端末
100,300,400,600,800 通信端末
101,201 受信部
102,202 データ処理部
103 確認パケット生成部
104 選択チャネル通知生成部
105,206 送信部
106 ビーコン処理部
110,310,410,505 チャネル制御部
203 管理部
204,504,807 送信要求生成部
205 ビーコン生成部
311 取得部
312,412 キャプチャ部
313,413 検出部
314 選択部
407 台数通知生成部
607 アドレス記憶部
608 生成部
705 制御部
Claims (15)
- 複数の周波数チャネルのうちから選択された一つの周波数チャネルを使用して信号を送信および受信する通信部と、
前記複数の周波数チャネルを順次切り替えながら、制御装置から送信される通知信号であって、当該周波数チャネルを使用して無線通信を行っている他の通信端末の数を示す通知信号を前記通信部に受信させることにより、無線通信を行っている他の通信端末の数を周波数チャネル毎に検出する第1の検出部と、
前記複数の周波数チャネルを順次切り替えながら、当該周波数チャネルを使用して無線通信を行っている他の通信端末から送信される確認信号を前記通信部に受信させることにより、受信した前記確認信号で確認された前記他の通信端末の数を周波数チャネル毎に検出する第2の検出部と、
前記複数の周波数チャネルのうち、前記第1の検出部で検出された前記他の通信端末の数と、前記第2の検出部で確認された前記他の通信端末の数との差が最も小さい周波数チャネルを選択して、前記通信部に前記制御装置との間で信号を送信および受信させるチャネル制御部とを備える
通信端末。 - 前記チャネル制御部は、前記複数の周波数チャネルのうち、前記第1の検出部で検出された前記他の通信端末の数と、前記第2の検出部で確認された前記他の通信端末の数とが等しい周波数チャネルを選択して、前記通信部に前記制御装置との間で信号を送信および受信させる
請求項1に記載の通信端末。 - 前記チャネル制御部は、前記制御装置に対して、周波数チャネル毎の前記他の通信端末の数を前記第1の検出部で検出した後、各周波数チャネルを使用して無線通信を行っている前記他の通信端末に対して前記確認信号の送信を要求する要求信号の送信を依頼するための依頼信号を、前記通信部に送信させる
請求項1又は2に記載の通信端末。 - 該通信端末は、さらに、前記第1の検出部で周波数チャネル毎の前記他の通信端末の数を検出している間に、当該他の通信端末が送信する信号を前記通信部に受信させることにより、当該信号の送信元端末の数を周波数チャネル毎に検出する第3の検出部を備え、
前記チャネル制御部は、前記制御装置に対して、前記通知信号に含まれる通信端末の数と前記送信元端末の数との差が小さい周波数チャネルから順に前記要求信号を送信するように依頼する前記依頼信号を、前記通信部に送信させる
請求項3に記載の通信端末。 - 該通信端末は、さらに、前記第1の検出部で周波数チャネル毎の前記他の通信端末の数を検出している間に、当該他の通信端末が送信する信号を前記通信部に受信させることにより、当該信号の送信元端末を特定する情報を周波数チャネル毎に検出する第3の検出部を備え、
前記チャネル制御部は、前記制御装置に対して、前記第3の検出部で検出できなかった通信端末にのみ前記要求信号を送信するように依頼する前記依頼信号を、前記通信部に送信させる
請求項3に記載の通信端末。 - 該通信端末は、さらに、前記複数の周波数チャネルを順次切り替えながら、当該周波数チャネルを使用して無線通信を行っている前記他の通信端末に前記確認信号の送信を要求するための要求信号を生成し、前記通信部に送信させる信号生成部を備える
請求項1又は2に記載の通信端末。 - 通信端末と無線通信を行う制御装置であって、
複数の周波数チャネルのうちから選択された一つの周波数チャネルを使用して信号を送信および受信する通信部と、
複数の周波数チャネルそれぞれについて、当該周波数チャネルを使用して無線通信を行っている通信端末の情報を保持する管理部と、
前記複数の周波数チャネルを順次切り替えながら、新たに通信を開始しようとする通信端末に対して、当該周波数チャネルを使用して無線通信を行っている通信端末の数を含む通知信号を生成し、前記通信部に送信させる第1の信号生成部と、
前記複数の周波数チャネルを順次切り替えながら、当該周波数チャネルを使用して無線通信を行っている通信端末に対して、新たに通信を開始しようとする通信端末への確認信号の送信を要求する要求信号を生成し、前記通信部に送信させる第2の信号生成部とを備える
制御装置。 - 該制御装置は、さらに、各周波数チャネルを使用して無線通信を行っている通信端末に対する前記要求信号の送信を依頼する依頼信号であって、前記新たに無線通信を開始しようとする通信端末から送信される前記依頼信号に基づいて、前記第2の信号生成部に周波数チャネル毎の前記要求信号を生成させるチャネル制御部を備える
請求項7に記載の制御装置。 - 前記チャネル制御部は、前記新たに通信を開始しようとする通信端末が既に確認している周波数チャネル毎の通信端末の数を含む前記依頼信号を前記通信部に受信させ、前記複数の周波数チャネルのうち、前記管理部に保持されている通信端末の数と、前記依頼信号に含まれる通信端末の数との差が小さい周波数チャネルから順に、前記第2の信号生成部に前記要求信号を生成させる
請求項8に記載の制御装置。 - 前記チャネル制御部は、前記新たに通信を開始しようとする通信端末が既に確認している通信端末を特定する情報を含む前記依頼信号を前記通信部に受信させ、前記新たに通信を開始しようとする通信端末が確認できなかった通信端末のみに対して送信される前記要求信号を、前記第2の信号生成部に生成させる
請求項8又は9に記載の制御装置。 - 該制御装置は、前記管理部で管理されている各通信端末の一定時間毎の通信量を集計し、前記複数の周波数チャネルのうち、前記新たに通信を開始しようとする通信端末で確認信号を受信できない通信端末の通信量が少ない周波数チャネルを選択させる
請求項7~10のいずれか1項に記載の制御装置。 - 特定の周波数チャネルで無線通信を行う通信方法であって、
複数の周波数チャネルを順次切り替えながら、制御装置から送信される前記通知信号であって、当該周波数チャネルを使用して無線通信を行っている他の通信端末の数を示す通知信号を受信することにより、無線通信を行っている他の通信端末の数を周波数チャネル毎に検出する端末数検出ステップと、
前記複数の周波数チャネルを順次切り替えながら、当該周波数チャネルを使用して無線通信を行っている他の通信端末から送信される確認信号を受信することにより、受信した前記確認信号で確認された前記他の通信端末の数を周波数チャネル毎に検出する確認信号検出ステップと、
前記複数の周波数チャネルのうち、前記端末数検出ステップで検出された前記他の通信端末の数と、前記確認信号検出ステップで確認された前記他の通信端末の数との差が最も小さい周波数チャネルを選択して、前記制御装置との間で信号を送信および受信する通信ステップとを含む
通信方法。 - 通信端末と無線通信を行う制御装置の制御方法であって、
複数の周波数チャネルそれぞれについて、当該周波数チャネルを使用して無線通信を行っている通信端末の情報を保持するステップと、
前記複数の周波数チャネルを順次切り替えながら、新たに通信を開始しようとする通信端末に対して、当該周波数チャネルを使用して無線通信を行っている通信端末の数を含む通知信号を送信するステップと、
前記複数の周波数チャネルを順次切り替えながら、当該周波数チャネルを使用して無線通信を行っている通信端末に対して、新たに通信を開始しようとする通信端末への確認信号の送信を要求する要求信号を送信するステップとを含む
制御方法。 - コンピュータに、無線通信を行わせるプログラムであって、
複数の周波数チャネルを順次切り替えながら、前記制御装置から送信される端末数通知信号であって、当該周波数チャネルを使用して無線通信を行っている他の通信端末の数を示す通知信号を受信することにより、無線通信を行っている他の通信端末の数を周波数チャネル毎に検出する端末数検出ステップと、
前記複数の周波数チャネルを順次切り替えながら、当該周波数チャネルを使用して無線通信を行っている他の通信端末から送信される確認信号を受信することにより、受信した前記確認信号で確認された前記他の通信端末の数を周波数チャネル毎に検出する確認信号検出ステップと、
前記複数の周波数チャネルのうち、前記端末数検出ステップで検出された前記他の通信端末の数と、前記確認信号検出ステップで確認された前記他の通信端末の数との差が最も小さい周波数チャネルを選択して、前記制御装置との間で信号を送信および受信する通信ステップとを、コンピュータに実行させる
プログラム。 - 無線通信を行う通信端末で用いられる集積回路であって、
複数の周波数チャネルのうちから選択された一つの周波数チャネルを使用して信号の送信および受信する通信部と、
前記複数の周波数チャネルを順次切り替えながら、前記制御装置から送信される通知信号であって、当該周波数チャネルを使用して無線通信を行っている他の通信端末の数を示す通知信号を前記通信部に受信させることにより、無線通信を行っている他の通信端末の数を周波数チャネル毎に検出する第1の検出部と、
前記複数の周波数チャネルを順次切り替えながら、当該周波数チャネルを使用して無線通信を行っている他の通信端末から送信される確認信号を前記通信部に受信させることにより、受信した前記確認信号で確認された前記他の通信端末の数を周波数チャネル毎に検出する第2の検出部と、
前記複数の周波数チャネルのうち、前記第1の検出部で検出された前記他の通信端末の数と、前記第2の検出部で確認された前記他の通信端末の数との差が最も小さい周波数チャネルを選択して、前記通信部に前記制御装置との間で信号を送信および受信させるチャネル制御部とを備える
集積回路。
Priority Applications (3)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
CN201180027635.5A CN102934507B (zh) | 2010-06-09 | 2011-06-08 | 通信终端、控制装置、通信方法、控制方法、程序、以及集成电路 |
US13/642,581 US8953543B2 (en) | 2010-06-09 | 2011-06-08 | Communication terminal, control device, communication method, control method, program, and integrated circuit |
JP2012519250A JP5576936B2 (ja) | 2010-06-09 | 2011-06-08 | 通信端末、制御装置、通信方法、制御方法、プログラム、及び集積回路 |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2010-132408 | 2010-06-09 | ||
JP2010132408 | 2010-06-09 |
Publications (1)
Publication Number | Publication Date |
---|---|
WO2011155191A1 true WO2011155191A1 (ja) | 2011-12-15 |
Family
ID=45097806
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/JP2011/003226 WO2011155191A1 (ja) | 2010-06-09 | 2011-06-08 | 通信端末、制御装置、通信方法、制御方法、プログラム、及び集積回路 |
Country Status (4)
Country | Link |
---|---|
US (1) | US8953543B2 (ja) |
JP (1) | JP5576936B2 (ja) |
CN (1) | CN102934507B (ja) |
WO (1) | WO2011155191A1 (ja) |
Cited By (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2014033424A (ja) * | 2012-03-01 | 2014-02-20 | Sony Corp | 情報処理装置、通信システムおよびチャンネル設定方法 |
WO2014125816A1 (ja) * | 2013-02-13 | 2014-08-21 | パナソニック株式会社 | 電力線搬送通信端末および検針端末 |
WO2015001742A1 (ja) * | 2013-07-05 | 2015-01-08 | パナソニックIpマネジメント株式会社 | 通信端末、および通信システム |
JP2015015547A (ja) * | 2013-07-03 | 2015-01-22 | 富士通株式会社 | 無線通信システム、無線基地局、及び、無線端末 |
JP2019050584A (ja) * | 2018-10-24 | 2019-03-28 | ヤマハ株式会社 | 無線中継装置、無線中継方法およびプログラム |
Families Citing this family (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP6045937B2 (ja) * | 2013-02-22 | 2016-12-14 | 東京エレクトロン株式会社 | 群管理システム及びプログラム |
US9949281B2 (en) | 2013-06-27 | 2018-04-17 | Telefonaktiebolaget L M Ericsson (Publ) | Method and radio node for managing resources for D2D discovery in an ad-hoc radio communication network |
WO2020144932A1 (ja) * | 2019-01-08 | 2020-07-16 | ソニー株式会社 | 通信装置及び通信方法 |
JP2020195065A (ja) * | 2019-05-28 | 2020-12-03 | パナソニックIpマネジメント株式会社 | 通信システム、通信装置、プログラム、及び通信確認方法 |
Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2002359864A (ja) * | 2001-06-01 | 2002-12-13 | Nec Corp | 移動端末局の基地局帰属切替方法 |
JP2007158765A (ja) * | 2005-12-06 | 2007-06-21 | Hitachi Communication Technologies Ltd | 無線通信端末及びその中継装置の負荷分散方法 |
JP2007274145A (ja) * | 2006-03-30 | 2007-10-18 | Oki Electric Ind Co Ltd | 無線アクセス制御装置 |
Family Cites Families (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US7599698B2 (en) * | 2003-12-29 | 2009-10-06 | Telefonaktiebolaget Lm Ericsson (Publ) | Network controlled channel information reporting |
US9014102B2 (en) * | 2006-04-20 | 2015-04-21 | Abb Inc. | Mobile access node channel selection within a mesh network |
CN101123802B (zh) | 2006-08-08 | 2012-01-11 | 株式会社Ntt都科摩 | 无线局域网中选择接入点的方法和装置 |
CN101483917A (zh) * | 2008-01-10 | 2009-07-15 | 华为技术有限公司 | 频带接入切换方法、终端和基站 |
CN101409801B (zh) * | 2008-12-01 | 2011-05-04 | 宇龙计算机通信科技(深圳)有限公司 | 一种电视频道切换的方法及系统 |
US8559323B2 (en) * | 2010-03-10 | 2013-10-15 | Cisco Technology, Inc. | Downlink OFDMA for service sets with mixed client types |
US8422444B2 (en) * | 2010-06-04 | 2013-04-16 | Microsoft Corporation | Dynamic channel and transmission rate selection |
-
2011
- 2011-06-08 WO PCT/JP2011/003226 patent/WO2011155191A1/ja active Application Filing
- 2011-06-08 US US13/642,581 patent/US8953543B2/en not_active Expired - Fee Related
- 2011-06-08 CN CN201180027635.5A patent/CN102934507B/zh not_active Expired - Fee Related
- 2011-06-08 JP JP2012519250A patent/JP5576936B2/ja not_active Expired - Fee Related
Patent Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2002359864A (ja) * | 2001-06-01 | 2002-12-13 | Nec Corp | 移動端末局の基地局帰属切替方法 |
JP2007158765A (ja) * | 2005-12-06 | 2007-06-21 | Hitachi Communication Technologies Ltd | 無線通信端末及びその中継装置の負荷分散方法 |
JP2007274145A (ja) * | 2006-03-30 | 2007-10-18 | Oki Electric Ind Co Ltd | 無線アクセス制御装置 |
Cited By (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2014033424A (ja) * | 2012-03-01 | 2014-02-20 | Sony Corp | 情報処理装置、通信システムおよびチャンネル設定方法 |
US9706338B2 (en) | 2012-03-01 | 2017-07-11 | Sony Corporation | Information processing device, communication system, and channel setting method |
WO2014125816A1 (ja) * | 2013-02-13 | 2014-08-21 | パナソニック株式会社 | 電力線搬送通信端末および検針端末 |
JP5991635B2 (ja) * | 2013-02-13 | 2016-09-14 | パナソニックIpマネジメント株式会社 | 電力線搬送通信端末および検針端末 |
JP2015015547A (ja) * | 2013-07-03 | 2015-01-22 | 富士通株式会社 | 無線通信システム、無線基地局、及び、無線端末 |
WO2015001742A1 (ja) * | 2013-07-05 | 2015-01-08 | パナソニックIpマネジメント株式会社 | 通信端末、および通信システム |
JP2015015644A (ja) * | 2013-07-05 | 2015-01-22 | パナソニックIpマネジメント株式会社 | 通信端末、および通信システム |
JP2019050584A (ja) * | 2018-10-24 | 2019-03-28 | ヤマハ株式会社 | 無線中継装置、無線中継方法およびプログラム |
Also Published As
Publication number | Publication date |
---|---|
US8953543B2 (en) | 2015-02-10 |
CN102934507B (zh) | 2016-10-12 |
US20130039323A1 (en) | 2013-02-14 |
CN102934507A (zh) | 2013-02-13 |
JPWO2011155191A1 (ja) | 2013-08-01 |
JP5576936B2 (ja) | 2014-08-20 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
JP5576936B2 (ja) | 通信端末、制御装置、通信方法、制御方法、プログラム、及び集積回路 | |
US10448424B2 (en) | Method and apparatus for use of simultaneous multiple channels in the dynamic frequency selection band in wireless networks | |
US10034178B2 (en) | Method and apparatus for multi-channel operation in wireless local area network system | |
JP5573571B2 (ja) | 無線通信装置、無線通信システム、プログラム、および無線通信方法 | |
KR100709501B1 (ko) | 피코넷 통신 시스템 내의 이웃들을 발견하기 위한 방법 및장치 | |
US11013040B2 (en) | System and method for association of transitory WiFi users | |
KR101601616B1 (ko) | 다중 채널 Wi-Fi 시스템에서 능동 스캐닝을 위한 시스템 및 방법 | |
US8432854B2 (en) | Method and system of beacon transmission and reception | |
KR101531382B1 (ko) | 비콘 충돌 가능성을 감소시키는 방법 | |
KR101094008B1 (ko) | 미디어 액세스 시스템의 마스터-슬레이브 핸드오버용 단말 장치 및 방법 | |
CN103491569A (zh) | 用于无线短距离通信断开的方法、装置和计算机程序产品 | |
US20100195590A1 (en) | Method and apparatus for radio spectrum sensing or monitoring | |
US20100142423A1 (en) | Method and system of radio frequency (rf) power transmission in a wireless network | |
KR20070106008A (ko) | 무선 네트워크에서의 비콘 전송 방법 | |
JP2011114377A (ja) | 無線通信装置、無線通信システム、無線通信方法およびプログラム | |
US20110179174A1 (en) | Apparatus identification in coexistence networking | |
CN102202423A (zh) | 无线lan系统、无线lan装置及设定信息设定方法 | |
KR20110068810A (ko) | 무선통신 시스템에서의 핸드오버 수행 방법 | |
JP5586047B2 (ja) | 無線通信方法及びシステム |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
WWE | Wipo information: entry into national phase |
Ref document number: 201180027635.5 Country of ref document: CN |
|
121 | Ep: the epo has been informed by wipo that ep was designated in this application |
Ref document number: 11792150 Country of ref document: EP Kind code of ref document: A1 |
|
WWE | Wipo information: entry into national phase |
Ref document number: 2012519250 Country of ref document: JP |
|
WWE | Wipo information: entry into national phase |
Ref document number: 13642581 Country of ref document: US |
|
NENP | Non-entry into the national phase |
Ref country code: DE |
|
122 | Ep: pct application non-entry in european phase |
Ref document number: 11792150 Country of ref document: EP Kind code of ref document: A1 |