WO2009130906A1 - 通信装置及び通信方法 - Google Patents
通信装置及び通信方法 Download PDFInfo
- Publication number
- WO2009130906A1 WO2009130906A1 PCT/JP2009/001862 JP2009001862W WO2009130906A1 WO 2009130906 A1 WO2009130906 A1 WO 2009130906A1 JP 2009001862 W JP2009001862 W JP 2009001862W WO 2009130906 A1 WO2009130906 A1 WO 2009130906A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- packet
- control
- flooding
- terminal
- communication
- Prior art date
Links
- 238000004891 communication Methods 0.000 title claims abstract description 109
- 238000000034 method Methods 0.000 title claims description 20
- 230000005540 biological transmission Effects 0.000 claims description 142
- 238000010586 diagram Methods 0.000 description 14
- 230000006870 function Effects 0.000 description 10
- 230000001934 delay Effects 0.000 description 3
- 230000003111 delayed effect Effects 0.000 description 2
- 238000001514 detection method Methods 0.000 description 2
- 230000000737 periodic effect Effects 0.000 description 2
- 238000010494 dissociation reaction Methods 0.000 description 1
- 230000005593 dissociations Effects 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 238000011835 investigation Methods 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]
- H04W74/0825—Non-scheduled access, e.g. ALOHA using carrier sensing, e.g. carrier sense multiple access [CSMA] with collision detection
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L49/00—Packet switching elements
- H04L49/55—Prevention, detection or correction of errors
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L69/00—Network arrangements, protocols or services independent of the application payload and not provided for in the other groups of this subclass
- H04L69/22—Parsing or analysis of headers
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B3/00—Line transmission systems
- H04B3/54—Systems for transmission via power distribution lines
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04W—WIRELESS COMMUNICATION NETWORKS
- H04W40/00—Communication routing or communication path finding
- H04W40/24—Connectivity information management, e.g. connectivity discovery or connectivity update
- H04W40/30—Connectivity information management, e.g. connectivity discovery or connectivity update for proactive routing
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04W—WIRELESS COMMUNICATION NETWORKS
- H04W84/00—Network topologies
- H04W84/18—Self-organising networks, e.g. ad-hoc networks or sensor networks
Definitions
- the present invention relates to a communication device and a communication method using a power line as a communication path.
- base stations periodically send out beacons as control packets.
- the mobile terminal moves to the beacon reach range, the mobile terminal receives the beacon and detects that it has entered a range where communication with the base station is possible.
- all mobile terminals that have received a beacon perform communication by relaying the base station.
- the control information exchange method for specifying the relay terminal includes a proactive method (for example, see Non-Patent Documents 1 and 2) that periodically exchanges control information, and a control information exchange method that is performed when data communication is started. It is classified as an active system (for example, see Non-Patent Documents 3 and 4). In general, it is said that the proactive method is effective when the moving speed of the terminal is slow, and the reactive method is effective when the moving speed of the terminal is fast.
- PLC Power Line Communication
- the state of the communication path is constantly changed according to the use status of the electric equipment, for example, depending on the situation such as the cleaner being switched on, The range in which communication with the relay terminal can be changed according to the change in the state of the communication path. For this reason, the relay terminal that is the source of the control packet received by a certain PLC terminal also changes in accordance with the change in the state of the communication path, and the number of relay terminals may increase.
- the control packets are transmitted from each of the plurality of relay terminals. Since the control packet from the relay terminal is periodically transmitted, the control packets transmitted from the relay terminals may collide with each other on the network when the periodic timing overlaps. In this case, the PLC terminal cannot receive the control packet. As a result, there is a problem that the PLC terminal continues to be disconnected from the network.
- the PLC terminal that receives the control packet has a problem that it cannot determine whether the control packet cannot be received due to noise on the network or whether the control packet cannot be received due to a collision of the control packets.
- a communication device includes a communication unit that receives a control packet that periodically appears on a communication path, and a plurality of control packets that have at least a payload portion incomplete within a predetermined period. If received, if it is determined that the source address included in the header part of the control packet with incomplete payload includes the same address, it is determined that control packets transmitted from multiple terminals collide And a control unit to perform.
- the communication device has a communication unit that receives control packets that periodically appear in a communication path and a plurality of control packets that have at least a payload portion incomplete within a predetermined period, and the payload portion is incomplete
- a control unit that determines that control packets transmitted from a plurality of terminals have collided when it is determined that the source address included in the header part of the control packet is not the same. is there.
- the timing at which each of the plurality of relay terminals sends out the control packet onto the network shifts the backoff time when transmitting the control packet between the plurality of relay terminals. Even if the control packet collides, the header portion of the control packet transmitted earlier than the others is likely to reach the PLC terminal of the communication partner.
- the presence or absence of collision of control packets transmitted from a plurality of terminals is determined by paying attention to the header portion of the control packet.
- the communication device of this aspect when a plurality of control packets with incomplete payload portions are received within a predetermined period for control packets that periodically appear on the communication path, the header of the control packet with incomplete payload portions It is determined whether or not the source address included in the part includes the same address.
- the communication device determines that control packets transmitted from a plurality of terminals collide when the source addresses include those that are not the same. In this way, the communication device determines whether or not there is a collision of the control packet based on the difference in the source address included in the header part that is likely to reach the communication partner as compared with the payload part of the control packet.
- the communication apparatus can prevent a state in which the communication apparatus is disconnected from the network due to collision of control packets transmitted from a plurality of relay terminals.
- the control unit includes an incomplete control packet in which the payload part is not the same as the transmission source address included in the header part of the control packet. If it is determined that the transmission source address included in the header portion of the header and the parent transmission source address that transmitted the control packet are the same, it is determined that the control packets transmitted from a plurality of terminals collide.
- the control unit when the control unit does not receive the control packet for a certain period, the payload part received within the predetermined period is included in the header parts of the plurality of incomplete control packets. It is determined whether or not the source address includes the same address.
- the payload part received within the predetermined period includes the one that is not the same as the source address included in the header parts of the plurality of incomplete control packets. It is determined whether or not. As a result, if there is a possibility that the control packet cannot be received because the control packet has collided on the network when the control packet periodically appearing on the communication path is not received for a certain period, Therefore, it is possible to efficiently determine whether or not there is a control packet collision.
- the control unit when the control unit determines that the control packets transmitted from the plurality of terminals collide with each other, the control unit controls one terminal among the plurality of terminals. An instruction to delay the packet transmission timing.
- the communication apparatus of this aspect when it is determined that the control packets transmitted from the plurality of terminals collide, an instruction to delay the transmission timing of the control packet is given to one terminal among the plurality of terminals. To do. Thereby, since the control packet transmitted from one terminal that has received the instruction is transmitted after the control packet transmitted from the other terminal among the plurality of terminals, the control packet is transmitted from one terminal among the plurality of terminals. Can receive control packets. As a result, the communication device cannot continuously receive the control packet due to the collision of the control packet, and can effectively prevent the state where the communication device is disconnected from the network.
- control unit gives an instruction to delay the transmission timing of the control packet by at least one packet.
- the control unit delays the transmission timing of the control packet by at least one packet, so that the control packet transmitted from one terminal among the plurality of terminals is transmitted to the other terminal. Since the packet is transmitted at least one packet after the control packet transmitted from, the certainty of reception of the control packet can be guaranteed.
- the control unit when the control unit receives a plurality of control packets in which at least the payload portion is incomplete within a predetermined period and the header portion of the control packet is also incomplete, the communication range To change the transmission probability of the control packet.
- the communication device of this aspect when a plurality of control packets with at least a payload portion incomplete are received within a predetermined period and the header portion of the control packet is also incomplete, for a terminal existing in the communication range To change the transmission probability of the control data. As a result, the situation in which the control packet cannot be continuously received is changed by an instruction from the receiving side of the control packet, so that the possibility of receiving the control packet can be increased.
- control packet is transmitted by broadcast.
- the communication device of this aspect can also be applied to devices in which control packets are transmitted by broadcast.
- the communication device is characterized in that, in the above aspect, the control packet includes a beacon signal.
- the communication device of this aspect can also be applied when the control packet is a beacon signal.
- the communication path is a power line.
- the communication device of this aspect can be applied to a communication channel that is a power line.
- the communication method receives a control packet that periodically appears on a communication path, and receives a plurality of control packets with at least a payload portion incomplete within a predetermined period. If it is determined that the same source address is included in the header part, it is determined that control packets transmitted from a plurality of terminals collide.
- the presence / absence of a control packet collision is determined based on the difference in the transmission source address included in the header portion that is likely to reach the communication partner as compared with the payload portion of the control packet. Therefore, it can be easily determined whether the control packet cannot be received due to noise or whether the control packet cannot be received due to the occurrence of a collision. As a result, it is possible to prevent the state of being disconnected from the network due to the collision of control packets transmitted from a plurality of relay terminals.
- the communication terminal device of the above aspect in an ad hoc network using a power line, if it is not possible to receive a control packet for a certain period, it can be determined whether it cannot be received due to noise on the network, or cannot be received due to a collision of control packets, In addition, it is possible to prevent the state where the network is disconnected from the network due to the collision of control packets transmitted from a plurality of relay terminals.
- FIG. 1 is a network configuration diagram showing an embodiment of the present invention. It is the figure which showed the detailed structure of the terminal used for one embodiment of this invention.
- 2 is a functional block diagram of a CPU 202.
- FIG. FIG. 4 is a state diagram when no packet collision occurs in one embodiment. It is a tree structure figure when the collision of the packet does not generate
- FIG. 6 is a state diagram when a packet collision occurs in one embodiment. It is a tree structure figure when the collision of the packet has occurred in one embodiment. It is the sequence diagram which showed transmission / reception of the flooding packet in one embodiment. It is the other sequence diagram which showed transmission / reception of the flooding packet in one embodiment. It is the figure which showed the detection method of the relay terminal which has generated the collision of the packet. It is the figure which showed the operation
- FIG. 1 is a diagram showing a network in which a communication apparatus and a communication method according to an embodiment of the present invention are used.
- the communication apparatus corresponds to each terminal of transmission, reception, and relay. Since the service area 101 of the network is larger than the coverage area of each terminal, an ad hoc network that performs mutual communication via the relay terminals 103 to 107 is configured. All terminals (including the receiving terminals 108 to 110) in the service area 101 receive which control packets related to the route information and the like periodically transmitted from the transmitting terminal 102, and which terminals are relayed between the terminals. It is possible to select 103 to 107 and perform communication. As a method for selecting a relay terminal for transmitting a control packet to all terminals, for example, a proactive method is used.
- FIG. 2 is a diagram showing a detailed configuration of each terminal.
- each terminal includes a memory 201 including various control programs and work areas, a CPU 202 that controls the entire terminal, and a network interface 203 that is connected to a power line and communicates various data via the power line. Yes.
- Each terminal executes a program stored in the memory 201 by the CPU 202, transmits data via the network interface 203, and decrypts data received via the network interface 203 by the CPU 202.
- the CPU 202 can be described as a control unit for controlling the entire terminal, and the network interface 203 can be described as a communication unit for performing communication of the entire terminal.
- FIG. 3 is a functional block diagram illustrating each function executed by the CPU 202.
- the reception processing unit 301 receives all packets including the control packet.
- the reception processing unit 301 determines whether or not the received packet is a packet transmitted to all terminals (hereinafter referred to as “flooding packet”) from the packet header. Identify.
- the reception processing unit 301 outputs information such as the arrival interval of the flooding packet and the transmission source address to the collision determination unit 303.
- the collision determination unit 303 determines whether the loss of the flooding packet is due to collision or noise based on the information output from the reception processing unit 301. . Specifically, the collision determination unit 303 continuously receives incomplete flooding packets for a certain period and detects a plurality of source addresses from the header part of the incomplete flooding packet. Is determined to have occurred. That is, when a plurality of relay terminals transmit control packets, the timing at which each of the plurality of relay terminals sends out the control packet on the network shifts the back-off time when transmitting the control packet among the plurality of relay terminals. Therefore, even if the control packet collides, there is a high possibility that the header part of the control packet transmitted earlier than the others can be received.
- the communication terminal can determine whether the loss of the flooding packet is due to collision or noise.
- the collision determination unit 303 instructs the terminal that transmits the flooding packet to send an instruction to change the transmission timing of the flooding packet (hereinafter, “ The control packet transmission unit 304 is requested to transmit “transmission timing control packet”.
- the collision determination unit 303 continuously receives incomplete flooding packets for a certain period of time, and when the header part itself is not detected from the incomplete flooding packet, It can be determined that a loss has occurred. That is, when the header part cannot be detected from an incomplete flooding packet for a certain period of time, the number of terminals that transmit flooding packets existing on the network has increased. It is thought that the probability of collisions increases.
- the collision determination unit 303 transmits a control packet (hereinafter referred to as “transmission probability control packet”) for instructing a terminal existing in the communication range of the terminal to change the transmission probability of the flooding packet.
- the control packet transmission unit 304 is requested to transmit.
- the transmission probability of a flooding packet defines the number of times a flooding packet is transmitted within a predetermined period.
- a relay terminal that has received a transmission probability control packet transmits a flooding packet by selecting 3 times out of 5 transmission timings instead of transmitting a flooding packet 5 times within a predetermined period.
- the transmission probability of flooding packets is changed. In this case, since the situation where the flooding packet cannot be continuously received is changed by an instruction from the receiving terminal side, the possibility of receiving the flooding packet increases.
- the collision determination unit 303 determines that a plurality of source addresses are not detected from the header portion of the flooding packet, the packet loss continues for a certain period when the communication apparatus functions as a receiving terminal. It is determined that the loss of the flooding packet is temporary due to noise.
- the control packet transmission unit 304 When the communication apparatus functions as a receiving terminal, the control packet transmission unit 304 outputs a control packet to the transmission processing unit 302 in accordance with a request from the collision determination unit 303.
- the control packet transmission unit 304 selects one of the plurality of detected source addresses from the header portion of the plurality of flooding packets, and selects the selected transmission source address.
- a transmission timing control packet to be transmitted by unicast is generated for one transmission source address.
- the control packet transmission unit 304 generates a transmission timing control packet that requests to shift the transmission timing of the flooding packet by one packet. In this case, since the flooding packet transmitted from one terminal among the plurality of terminals is transmitted at least one packet after the flooding packet transmitted from the other terminal, the certainty of reception of the flooding packet is ensured. Can be guaranteed.
- the control packet transmission unit 304 when the control packet transmission unit 304 is requested by the collision determination unit 303 to transmit a transmission probability control packet, the control packet transmission unit 304 sets a transmission probability according to the number of neighboring terminals, the loss rate of the unicast packet, and the like, and transmits by broadcast.
- a transmission probability control packet to be generated is generated.
- the control packet transmission unit 304 transmits the flooding packet five times within a predetermined period to the relay terminal existing in the communication range of the terminal, and changes the control packet transmission unit 304 three times out of the five transmission timings.
- a transmission probability control packet that requests to transmit a flooding packet is generated. In this case, since the situation where the flooding packet cannot be continuously received is changed by an instruction from the receiving terminal side, the possibility of receiving the flooding packet increases.
- the transmission control unit 305 interprets the control packet passed from the reception processing unit 301 when the communication apparatus functions as a relay terminal. If the received control packet is a transmission timing control packet, the transmission control unit 305 changes the transmission timing of the flooding packet. Specifically, the transmission control unit 305 controls the transmission timing of the flooding packet in the transmission processing unit 302 according to the received transmission timing control packet. In addition, when the received control packet is a transmission probability control packet, the transmission control unit 305 changes the transmission probability of the flooding packet. Specifically, the transmission control unit 305 controls the transmission probability of the flooding packet in the transmission processing unit 302 according to the received transmission probability control packet.
- the transmission processing unit 302 performs transmission processing for all packets including a packet for which a transmission request has been received from the control packet transmission unit 304. When there is an instruction from the transmission control unit 305, the transmission processing unit 302 changes transmission processing such as the transmission timing or transmission probability of the flooding packet.
- FIG. 4 is a network diagram when no flooding packet collision occurs.
- transmission terminal A 401 there are four terminals in service area 101: transmission terminal A 401, reception terminal B 402, relay terminal C 403, and reception terminal D 404.
- the cover area 405 of the transmission terminal A401 includes the reception terminal B402 and the relay terminal C403, but does not include the reception terminal D404.
- the receiving terminal D404 is present in the cover area 406 of the receiving terminal B402 and the cover area 407 of the relay terminal C403, but receives the flooding packet from the transmitting terminal A401 by having the relay terminal C403 relay. Is possible.
- FIG. 5 shows a flooding tree in the state of FIG.
- transmitting terminal A401 is connected to receiving terminal B402 and relay terminal C403, and receiving terminal D404 is connected to relay terminal C403.
- FIG. 6 is a network diagram when a new receiving terminal E601 enters the state of FIG. Referring to FIG. 6, the receiving terminal E601 is not included in the cover area 405 of the transmitting terminal A401 or the cover area 407 of the relay terminal C403. On the other hand, the receiving terminal E601 is included in the cover area 406 of the receiving terminal B402. For this reason, the receiving terminal B402 functions as a relay terminal. The receiving terminal E601 has the relay terminal B402 relay the flooding packet.
- FIG. 7 is a diagram showing a flooding tree in the state of FIG. Similarly to FIG. 5, the transmission terminal A 401 is connected to the relay terminal B 402 and the relay terminal C 403, and the reception terminal D 404 is connected to the relay terminal C 403. However, since the receiving terminal D404 is included in the cover area 406 of the receiving terminal B402, when the receiving terminal B402 becomes a relay terminal and starts relaying, the flooding packet is also received from the relay terminal B402. Here, the relay terminal B 402 and the relay terminal C 403 simultaneously receive the flooding packet from the transmission terminal A 401.
- receiving terminal D404 since the receiving terminal D404 is included in both the cover area 406 of the relay terminal B402 and the cover area 407 of the relay terminal C403, the flooding packet is simultaneously received from a plurality of terminals. For this reason, packet collision occurs, and the receiving terminal D404 cannot accurately receive packets from either. Therefore, it is necessary to change the transmission timing of the relay terminal B402 or the relay terminal C403.
- receiving terminal D404 detects that the cause of packet loss is a collision, and transmits a control packet for changing the transmission timing of a flooding packet to the network.
- FIG. 8A is a sequence diagram showing transmission / reception of a flooding packet in the present embodiment.
- the receiving terminal D404 receives the flooding packet 801 from the relay terminal C403 (see FIG. 4).
- the terminal B402 functions as a relay terminal, and the receiving terminal D404 receives the flooding packet 802 from the relay terminal B402 and the relay terminal C403 simultaneously (see FIG. 6).
- a collision occurs and the receiving terminal D404 cannot receive the flooding packet 802 in a complete form.
- an ad hoc network is configured with a non-moving terminal such as a PLC terminal, in this state, collisions will occur repeatedly, and subsequent flooding packets 803 and 804 cannot be received. That is, the state where the receiving terminal D404 is substantially removed from the network continues, and the receiving terminal D404 cannot return to the network.
- the PLC terminal does not leave due to movement from the cover area, it is possible to estimate that the collision is the cause when packet loss occurs continuously.
- the timing at which each of the plurality of relay terminals sends out the flooding packet to the network shifts the back-off time when transmitting the flooding packet between the plurality of relay terminals. Therefore, even if a flooding packet collides, there is a high possibility that the header part of the flooding packet transmitted earlier than the others will reach the receiving terminal.
- the receiving terminal D404 pays attention to the header part of the flooding packet and determines whether or not there is a collision of flooding packets transmitted from a plurality of relay terminals. That is, for a flooding packet that periodically appears in the network, the receiving terminal D404 receives a plurality of flooding packets with incomplete payload portions within a predetermined period, and the payload portion is included in the header portion of the incomplete flooding packet. It is determined whether or not a source address is not the same. Receiving terminal D404 determines that flooding packets transmitted from a plurality of relay terminals collide when non-identical source addresses are included.
- the receiving terminal D404 can prevent the state of being disconnected from the network due to collision of flooding packets transmitted from a plurality of relay terminals.
- the receiving terminal D404 investigates whether or not a flooding packet actually transmitted from a plurality of relay terminals is received, and any one of the plurality of relay terminals A transmission timing control packet 806 that delays the transmission timing of the flooding packet is transmitted to one.
- the transmission timing control packet 806 is transmitted to the relay terminal C403.
- the flooding packet transmitted from the relay terminal C403 that has received the transmission timing control packet 806 is transmitted after the flooding packet 805 transmitted from the relay terminal B402. Therefore, the receiving terminal D404 can receive a flooding packet from any one of the relay terminal B402 and the relay terminal C403.
- the transmission timing control packet 806 may delay, for example, the transmission timing of the flooding packet by at least one packet. In this case, since the flooding packet transmitted from the relay terminal C403 is transmitted after at least one packet after the flooding packet 805 transmitted from the relay terminal B402, the certainty of receiving the flooding packet can be ensured.
- the receiving terminal D404 may transmit the transmission timing control packet 806 to a terminal that has already received a flooding packet when the address of the relay terminal is not found. In that case, there is a possibility that the collision can be avoided without any particular investigation.
- the terminal C403 that has received the transmission timing control packet 806 sets the transmission timing of the flooding packet 805 after the transmission of the flooding packet of the terminal B402. As a result, the receiving terminal D404 can completely receive the flooding packet 805.
- FIG. 8B is another sequence diagram showing transmission / reception of a flooding packet in the present embodiment.
- the receiving terminal D404 receives the flooding packet 801 from the relay terminal C403 (see FIG. 4).
- the terminal B402 functions as a relay terminal, and the receiving terminal D404 receives the flooding packet 802 simultaneously from the relay terminal B402 and the relay terminal C403 (see FIG. 6). Therefore, a collision of the flooding packet 802 occurs, and the receiving terminal D404 cannot receive the flooding packet 802 in a complete form.
- an ad hoc network is configured with a non-moving terminal such as a PLC terminal, collision occurs repeatedly in this state, and subsequent flooding packets 803 and 804 cannot be received. That is, the receiving terminal D404 continues to be substantially out of the network and cannot return to the network.
- the PLC terminal does not leave due to movement from the cover area, it is possible to estimate that the collision is the cause when packet loss occurs continuously.
- the timing at which each of the plurality of relay terminals sends out the flooding packet to the network shifts the back-off time when transmitting the flooding packet between the plurality of relay terminals. Therefore, even if a flooding packet collides, there is a high possibility that the header part of the flooding packet transmitted earlier than the others will reach the receiving terminal.
- a transmission probability control packet 811 for instructing the terminal existing in the communication range of the receiving terminal to change the transmission probability of the flooding packet is transmitted by broadcast.
- the relay terminal C 403 that has received the transmission probability control packet 811 transmits the flooding packet by selecting 3 times out of the 5 transmission timings, instead of transmitting the flooding packet 5 times within a predetermined period.
- the transmission probability of the flooding packet is changed.
- the possibility that the receiving terminal D404 can receive the flooding packet 812, 813 or 814 increases.
- this transmission probability may be determined by the receiving terminal based on the number of neighboring terminals, the loss rate, or the like, or may be set by the transmitting terminal. After that, if the terminal does not go out of the network, the transmission probability may be changed and the transmission probability may be restored by returning the transmission probability.
- each terminal using CSMA transmits data after confirming that the communication path is continuously available for a certain time or more.
- This waiting time is a minimum time (hereinafter referred to as DIFS 901) plus a random length of waiting time (hereinafter referred to as back-off time 902). This prevents a situation in which a plurality of terminals transmit packets all at once after a certain period of time after the previous communication.
- the other terminal cannot detect that one terminal has started data transmission.
- the relay terminal C403 cannot detect that the relay terminal B402 has started data transmission (see FIG. 6).
- the back-off time is much shorter than the time until data reception is completed. Therefore, data transmission from the other terminal is started before the data reception from one terminal is completed, and a collision may occur.
- Information such as the transmission source address of the relay terminal of the flooding packet is generally contained in the head part of the packet called a header part. Since the time until the header part is received is short, it may be included in the back-off time. For example, the header part of the flooding packet transmitted from the relay terminal B402 is included in the back-off time that is a waiting time for the relay terminal C403 to transmit the flooding packet. In this case, the receiving terminal D404 can receive the header portion of the flooding packet transmitted from the relay terminal B402 even if a flooding packet collision occurs.
- the receiving terminal D404 uses this time to detect that a flooding packet is received from a plurality of relay terminals. That is, in this embodiment, receiving terminal D404 pays attention to the header portion of the flooding packet and determines whether or not there is a collision of flooding packets transmitted from a plurality of relay terminals. Specifically, when the receiving terminal D404 receives a plurality of flooding packets with incomplete payload portions within a predetermined period for flooding packets that periodically appear in the network, the receiving terminal D404 uses the header portion of the flooding packet with incomplete payload portions. It is determined whether or not the same source address is included. Receiving terminal D404 determines that flooding packets transmitted from a plurality of relay terminals collide when non-identical source addresses are included.
- the receiving terminal D404 can prevent a state in which the receiving terminal D404 is disconnected from the network due to a collision of flooding packets transmitted from a plurality of relay terminals.
- flooding packet transmission timing control when receiving a transmission timing control packet from the receiving terminal D404, the relay terminal C403 adds the time required for transmitting one flooding packet to the normal packet DIFS, for example, the minimum A flooding packet DIFS 1001 having a limited waiting time is assumed. As a result, the flooding packet transmitted from the relay terminal C403 that has received the transmission timing control packet is transmitted after the flooding packet transmitted from the relay terminal B402. Therefore, the receiving terminal D404 can receive a flooding packet from at least one of the relay terminal B402 and the relay terminal C403.
- the flooding packet transmitted from the relay terminal C403 is transmitted after at least one packet after the flooding packet 805 transmitted from the relay terminal B402. The certainty of packet reception can be ensured.
- FIG. 11 is a flowchart when each terminal receives a flooding packet.
- a receiving terminal that receives a flooding packet determines whether or not a flooding packet has been received for a certain period (step S1101).
- a flooding packet transmitted periodically is targeted, but the present invention is not limited to this.
- the receiving terminal is a PLC terminal and does not leave the cover area due to movement, so it can be estimated that a continuous packet loss causes a collision.
- a sequence number may be assigned to the flooding packet, and it may be confirmed that repeated packet loss has occurred due to missing sequence numbers.
- the receiving terminal determines whether or not it has received only the header part of the flooding packet (step S1102).
- the receiving terminal determines whether there are a plurality of transmission source addresses for one flooding packet (step S1103). If there are a plurality of source addresses for one flooding packet, the receiving terminal determines that a flooding packet loss has occurred due to a collision (step S1104).
- the timing at which each of the plurality of relay terminals sends out the flooding packet onto the network shifts the back-off time when the flooding packet is transmitted among the plurality of relay terminals. Therefore, even if a flooding packet collides, there is a high possibility that the header part of the flooding packet transmitted earlier than the others will reach the receiving terminal.
- the receiving terminal can prevent a state in which the receiving terminal is disconnected from the network due to a collision of flooding packets transmitted from a plurality of relay terminals.
- the receiving terminal transmits a transmission timing control packet to any one of a plurality of source addresses (step S1105).
- the flooding packet transmitted from the relay terminal that has received the transmission timing control packet is transmitted after the flooding packet transmitted from another relay terminal.
- the receiving terminal can receive the flooding packet from any of the plurality of relay terminals without collision.
- the receiving terminal cannot continuously receive the flooding packet due to the collision of the flooding packet, and can effectively prevent the state where the receiving terminal is out of the network.
- the transmission timing control packet may be one that delays the transmission timing of the flooding packet by at least one packet, for example. In this case, since the flooding transmitted from the relay terminal that has received the transmission timing control packet is transmitted at least one packet after the flooding packet transmitted from the other relay terminal, the certainty of receiving the flooding packet is ensured. it can.
- step S1102 if the receiving terminal has not received the flooding packet for a certain period and has not received the header of the flooding packet, it determines that a loss due to collision has occurred (step S1106). . In other words, when the header part of the flooding packet cannot be received for a certain period, the number of terminals that transmit flooding packets existing on the network has increased, resulting in an increase in the overlapping timing of flooding packet transmission and collision of flooding packets. Probability is also thought to increase.
- the receiving terminal transmits a transmission probability control packet for instructing the terminal existing in its communication range to change the transmission probability of the flooding packet (step S1107).
- a relay terminal that has received a transmission probability control packet transmits a flooding packet by selecting 3 times out of 5 transmission timings instead of transmitting a flooding packet 5 times within a predetermined period.
- the transmission probability of flooding packets is changed. In this case, since the situation where the flooding packet cannot be continuously received is changed by an instruction from the receiving terminal side, the possibility of receiving the flooding packet increases.
- step S1103 if the receiving terminal determines that a plurality of source addresses are not detected from the header portion of the flooding packet, although the packet loss continues for a certain period of time, the flooding packet loss is temporarily caused by noise. It judges that it is a thing, and returns to a normal process.
- FIG. 12 is a flowchart when each terminal transmits a flooding packet.
- the relay terminal that relays the flooding packet transmits the flooding packet (step S1201).
- the relay terminal determines whether a transmission probability control packet has been received from the receiving terminal (step S1202). If no transmission probability control packet is received, the process proceeds to step S1204.
- the relay terminal changes the transmission probability of the flooding packet according to the received transmission probability control packet (step S1203). For example, if the relay terminal transmits a flooding packet five times within a predetermined period, the relay terminal increases the transmission probability of the flooding packet so that three of the five transmission timings are selected and the flooding packet is transmitted. change. As a result, the situation in which the flooding packet cannot be continuously received is changed by an instruction from the receiving terminal, so that the receiving terminal is more likely to receive the flooding packet.
- the relay terminal determines whether a transmission timing control packet has been received (step S1204). When the transmission timing control packet is not received, the process returns to the flooding packet transmission process. On the other hand, when the relay terminal receives the transmission timing control packet, the relay terminal changes the transmission timing of the flooding packet according to the received transmission timing control packet (step S1205). Thereby, since the flooding packet transmitted from the relay terminal that has received the transmission timing control packet is transmitted after the flooding packet transmitted from the other relay terminal, the flooding packet is transmitted from at least one of the relay terminals at the receiving terminal. Can be received.
- the receiving terminal cannot continuously receive the flooding packet due to the collision of the flooding packet, and thus can be prevented from being substantially disconnected from the network. For example, if the transmission timing of the flooding packet is delayed by at least one packet, the flooding packet transmitted from the relay terminal that has received the transmission timing control packet will be at least one packet later than the flooding packet transmitted from the other relay terminal. Since it is transmitted, it is possible to ensure the certainty of receiving the flooding packet.
- a control packet in an ad hoc network using a power line, when a control packet cannot be received for a certain period of time, it is determined whether or not the control packet cannot be received due to a collision, and a control packet transmitted from a plurality of relay terminals is determined. It is possible to provide a communication device and a communication method that can prevent a state in which the network is disconnected from the network due to a collision.
Landscapes
- Engineering & Computer Science (AREA)
- Computer Networks & Wireless Communication (AREA)
- Signal Processing (AREA)
- Computer Security & Cryptography (AREA)
- Small-Scale Networks (AREA)
- Mobile Radio Communication Systems (AREA)
- Reduction Or Emphasis Of Bandwidth Of Signals (AREA)
- Electroluminescent Light Sources (AREA)
- Communication Control (AREA)
- Cable Transmission Systems, Equalization Of Radio And Reduction Of Echo (AREA)
Abstract
Description
図1は、本発明の一実施の態様に係る通信装置及び通信方法が用いられるネットワークを表した図である。図1において、通信装置は、送信、受信、及び中継の各端末に対応している。ネットワークのサービスエリア101は、各端末のカバーエリアよりも大きいため、中継端末103~107を介して相互の通信を行うアドホックネットワークを構成している。サービスエリア101内の全ての端末(受信端末108~110を含む)は、送信端末102から周期的に送信される経路情報等に関する制御パケットを受信することによって、各端末間でどの端末を中継端末103~107として選択し、通信を行えばよいかがわかる。制御パケットを全ての端末に送信するための中継端末を選択する方法は、例えばプロアクティブ方式を用いるものとする。
102~110、401~404、601 端末
201 メモリ
202 CPU
203 ネットワークインタフェース
301 受信処理部
302 送信処理部
303 衝突判定部
304 制御パケット送信部
305 送信制御部
405~407 カバーエリア
801~806、811~814 パケット
Claims (10)
- 通信路に周期的に出現する制御パケットを受信する通信部と、
所定期間内に少なくともペイロード部が不完全な制御パケットを複数受信した場合、前記ペイロード部が不完全な制御パケットのヘッダ部に含まれる送信元アドレスに同一でないものが含まれていると判断すると、複数の端末から送信された制御パケットが衝突していると判断する制御部とを備える、通信装置。 - 前記制御部は、前記ペイロード部が不完全な制御パケットのヘッダ部に含まれる送信元アドレスに同一でないものが含まれており、かつ前記不完全な制御パケットのヘッダ部に含まれる送信元アドレスと、前記制御パケットを送信した親送信元アドレスとが同一であると判断すると、前記複数の端末から送信された制御パケットが衝突していると判断することを特徴とする、請求項1に記載の通信装置。
- 前記制御部は、一定期間制御パケットを受信しない場合に、前記所定期間内に受信された前記ペイロード部が不完全な複数の制御パケットのヘッダ部に含まれる送信元アドレスに同一でないものが含まれているか否かを判断することを特徴とする、請求項1に記載の通信装置。
- 前記制御部は、前記複数の端末から送信された制御パケットが衝突していると判断した場合、前記複数の端末の中の1つの端末に対して、前記制御パケットの送信タイミングを遅らせる指示をすることを特徴とする、請求項1に記載の通信装置。
- 前記制御部は、前記制御パケットの送信タイミングを少なくとも1パケット分だけ遅らせる指示をするものであることを特徴とする、請求項4に記載の通信装置。
- 前記制御部は、前記所定期間内に少なくともペイロード部が不完全な制御パケットを複数受信し、かつ前記制御パケットのヘッダ部も不完全である場合、通信範囲に存在する端末に対して、前記制御パケットの送信確率を変更するよう指示することを特徴とする、請求項1に記載の通信装置。
- 前記制御パケットは、ブロードキャストで送信されるものであることを特徴とする、請求項1に記載の通信装置。
- 前記制御パケットは、ビーコン信号を含むことを特徴とする、請求項6に記載の通信装置。
- 前記通信路は、電力線であることを特徴とする、請求項1に記載の通信装置。
- 通信路に周期的に出現する制御パケットを受信し、所定期間内に少なくともペイロード部が不完全な制御パケットを複数受信した場合、前記ペイロード部が不完全な制御パケットのヘッダ部に含まれる送信元アドレスに同一でないものが含まれていると判断すると、複数の端末から送信された制御パケットが衝突していると判断することを特徴とする、通信方法。
Priority Applications (5)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US12/666,198 US9008090B2 (en) | 2008-04-25 | 2009-04-23 | Communication apparatus and communication method |
EP09734332A EP2271029B1 (en) | 2008-04-25 | 2009-04-23 | Collision detection in an ad-hoc power line communication network |
AT09734332T ATE557569T1 (de) | 2008-04-25 | 2009-04-23 | Kollisionserkennung in einem ad-hoc- kommunikationsnetzwerk über stromversorgungsleitungen |
CN2009800004885A CN101690018B (zh) | 2008-04-25 | 2009-04-23 | 通信装置及通信方法 |
JP2010509084A JP5298123B2 (ja) | 2008-04-25 | 2009-04-23 | 通信装置及び通信方法 |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2008115683 | 2008-04-25 | ||
JP2008-115683 | 2008-04-25 |
Publications (1)
Publication Number | Publication Date |
---|---|
WO2009130906A1 true WO2009130906A1 (ja) | 2009-10-29 |
Family
ID=41216647
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/JP2009/001862 WO2009130906A1 (ja) | 2008-04-25 | 2009-04-23 | 通信装置及び通信方法 |
Country Status (6)
Country | Link |
---|---|
US (1) | US9008090B2 (ja) |
EP (1) | EP2271029B1 (ja) |
JP (1) | JP5298123B2 (ja) |
CN (1) | CN101690018B (ja) |
AT (1) | ATE557569T1 (ja) |
WO (1) | WO2009130906A1 (ja) |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2016096450A (ja) * | 2014-11-14 | 2016-05-26 | 株式会社東芝 | 無線通信装置および無線通信システム |
JP2020145634A (ja) * | 2019-03-08 | 2020-09-10 | 富士電機株式会社 | 無線通信装置および無線通信システム |
Families Citing this family (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2009072175A1 (ja) * | 2007-12-03 | 2009-06-11 | Fujitsu Limited | パケット通信装置及びパケット通信方法 |
US8949881B2 (en) * | 2009-11-25 | 2015-02-03 | Olivier Koemmerling | Card sharing countermeasures |
DE112014005395T5 (de) * | 2013-11-26 | 2016-08-25 | Panasonic Intellectual Property Management Co., Ltd. | Drahtloskommunikationssystem |
US9756549B2 (en) | 2014-03-14 | 2017-09-05 | goTenna Inc. | System and method for digital communication between computing devices |
CN106788598B (zh) * | 2016-12-16 | 2020-09-08 | 北京智芯微电子科技有限公司 | 一种电力线通信的组网方法及装置 |
CN111757532B (zh) * | 2019-03-27 | 2022-08-30 | 大唐移动通信设备有限公司 | 无线自组网的同步信道冲突检测、消解方法、装置及节点 |
Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH09284304A (ja) * | 1996-04-17 | 1997-10-31 | Nec Corp | セル衝突検出装置 |
WO2005041487A1 (ja) * | 2003-10-24 | 2005-05-06 | Sony Corporation | 無線通信システム、無線通信装置及び無線通信方法、並びにコンピュータ・プログラム |
JP2008048304A (ja) * | 2006-08-21 | 2008-02-28 | Nec Corp | 通信システム、アドホック通信方法、携帯端末装置および基地局装置 |
Family Cites Families (17)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4534061A (en) * | 1983-09-06 | 1985-08-06 | General Electric Company | Deterministic multi-access method for a decentralized mobile radio system |
US5040175A (en) * | 1990-04-11 | 1991-08-13 | Ncr Corporation | Wireless information transmission system |
US5673254A (en) * | 1995-06-07 | 1997-09-30 | Advanced Micro Devices Inc. | Enhancements to 802.3 media access control and associated signaling schemes for ethernet switching |
US6990069B1 (en) * | 1997-02-24 | 2006-01-24 | At&T Corp. | System and method for improving transport protocol performance in communication networks having lossy links |
US6189035B1 (en) * | 1998-05-08 | 2001-02-13 | Motorola | Method for protecting a network from data packet overload |
JP2000261452A (ja) * | 1999-03-09 | 2000-09-22 | Fuji Xerox Co Ltd | ネットワークシステムおよび端末装置 |
US6427169B1 (en) * | 1999-07-30 | 2002-07-30 | Intel Corporation | Parsing a packet header |
US6804257B1 (en) * | 1999-11-25 | 2004-10-12 | International Business Machines Corporation | System and method for framing and protecting variable-lenght packet streams |
US7151754B1 (en) * | 2000-09-22 | 2006-12-19 | Lucent Technologies Inc. | Complete user datagram protocol (CUDP) for wireless multimedia packet networks using improved packet level forward error correction (FEC) coding |
EP1263168B1 (en) * | 2001-05-29 | 2006-06-28 | Kabushiki Kaisha Toshiba | Wireless communication apparatus |
KR100500515B1 (ko) * | 2003-06-30 | 2005-07-14 | 삼성전자주식회사 | 패킷 플로 제어 장치 및 방법 |
US8085806B2 (en) | 2003-09-26 | 2011-12-27 | Agere Systems Inc. | Method and apparatus for detecting a collision in a carrier sense multiple access wireless system |
CN1937615B (zh) * | 2005-09-20 | 2012-01-25 | 株式会社Ntt都科摩 | 无线分布式网络中的媒体接入控制方法和装置 |
EP1808983A1 (en) * | 2006-01-13 | 2007-07-18 | THOMSON Licensing | Process and devices for selective collision detection |
US8000341B2 (en) * | 2006-03-08 | 2011-08-16 | Alcatel Lucent | Methods and systems for detecting collisions in access/utilization of resources of contention |
US7761079B2 (en) * | 2006-06-09 | 2010-07-20 | Current Technologies, Llc | Power line communication device and method |
US8259647B2 (en) * | 2006-06-12 | 2012-09-04 | Samsung Electronics Co., Ltd. | System and method for wireless communication of uncompressed video having a link control and bandwidth reservation scheme for control/management message exchanges and asynchronous traffic |
-
2009
- 2009-04-23 CN CN2009800004885A patent/CN101690018B/zh active Active
- 2009-04-23 US US12/666,198 patent/US9008090B2/en active Active
- 2009-04-23 JP JP2010509084A patent/JP5298123B2/ja active Active
- 2009-04-23 EP EP09734332A patent/EP2271029B1/en active Active
- 2009-04-23 AT AT09734332T patent/ATE557569T1/de active
- 2009-04-23 WO PCT/JP2009/001862 patent/WO2009130906A1/ja active Application Filing
Patent Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH09284304A (ja) * | 1996-04-17 | 1997-10-31 | Nec Corp | セル衝突検出装置 |
WO2005041487A1 (ja) * | 2003-10-24 | 2005-05-06 | Sony Corporation | 無線通信システム、無線通信装置及び無線通信方法、並びにコンピュータ・プログラム |
JP2008048304A (ja) * | 2006-08-21 | 2008-02-28 | Nec Corp | 通信システム、アドホック通信方法、携帯端末装置および基地局装置 |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2016096450A (ja) * | 2014-11-14 | 2016-05-26 | 株式会社東芝 | 無線通信装置および無線通信システム |
JP2020145634A (ja) * | 2019-03-08 | 2020-09-10 | 富士電機株式会社 | 無線通信装置および無線通信システム |
Also Published As
Publication number | Publication date |
---|---|
EP2271029B1 (en) | 2012-05-09 |
US20100195656A1 (en) | 2010-08-05 |
EP2271029A4 (en) | 2011-05-04 |
ATE557569T1 (de) | 2012-05-15 |
EP2271029A1 (en) | 2011-01-05 |
CN101690018A (zh) | 2010-03-31 |
JPWO2009130906A1 (ja) | 2011-08-11 |
CN101690018B (zh) | 2013-09-25 |
JP5298123B2 (ja) | 2013-09-25 |
US9008090B2 (en) | 2015-04-14 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
JP5298123B2 (ja) | 通信装置及び通信方法 | |
Molins et al. | Slotted FAMA: a MAC protocol for underwater acoustic networks | |
CN105308871A (zh) | 利用不同的跳频调度快速重路由 | |
JP2009100443A (ja) | アドホックネットワークにおけるパケット送信経路設定方法およびこれを用いたネットワーク装置 | |
WO2012073578A1 (ja) | 無線マルチホップネットワークを用いた情報収集システム、端末、シンクノード、およびこれらの通信方法 | |
JP2006238341A (ja) | ネットワークスイッチ装置及び方法、無線アクセス装置、および、無線ネットワーク | |
Ng et al. | An underwater acoustic MAC protocol using reverse opportunistic packet appending | |
JP4633720B2 (ja) | メディアアクセスプロトコルを提供する方法 | |
CN101395857B (zh) | 用于在带有隐藏节点的自组网络中进行多跳数据传输的方法 | |
JP2008172283A (ja) | マルチホップ無線通信システムの構成方法、マルチホップ無線通信システム及び無線通信装置 | |
Oliveira et al. | Multi-hop routing within TDMA slots for teams of cooperating robots | |
JP2007251811A (ja) | 無線通信装置、無線通信方法および経路情報テーブルの作成方法 | |
KR101200792B1 (ko) | Mac 유니캐스트와 중계 노드를 이용한 네트워크 브로드캐스트 방법 | |
JP2005086570A (ja) | 通信制御方法及び通信端末 | |
JP2007235871A (ja) | 無線装置およびそれを用いた無線ネットワークシステム | |
Li et al. | Analysis of multipath routing for ad hoc networks using directional antennas | |
KR101293159B1 (ko) | 무선 애드혹 네트워크에서의 브로트캐스트 패킷 전송 방법 및 장치, 및 브로드캐스트 패킷 송수신 시스템 | |
JP2006005653A (ja) | 無線アクセス制御方法およびシステム | |
Natesapillai et al. | Reducing broadcast overhead using clustering based broadcast mechanism in Mobile Ad Hoc network | |
JP2009212978A (ja) | 無線端末、パケット転送制御方法及びそのプログラム | |
JP5504603B2 (ja) | 無線装置及び無線装置において使用されるプログラム | |
KR101401588B1 (ko) | 무선 멀티 홉 네트워크 내에서 데이터를 전송하기 위한 네트워크 노드들 및 방법 | |
Sen et al. | An end-to-end delay metric for multi-rate wireless mesh networks with cooperative retransmission | |
JP2005027248A (ja) | 無線パケット通信装置 | |
Wu et al. | Multi-hop broadcasting in WAVE multi-channel vehicular networks: Single transceiver case |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
WWE | Wipo information: entry into national phase |
Ref document number: 200980000488.5 Country of ref document: CN |
|
WWE | Wipo information: entry into national phase |
Ref document number: 2010509084 Country of ref document: JP |
|
WWE | Wipo information: entry into national phase |
Ref document number: 2009734332 Country of ref document: EP |
|
121 | Ep: the epo has been informed by wipo that ep was designated in this application |
Ref document number: 09734332 Country of ref document: EP Kind code of ref document: A1 |
|
WWE | Wipo information: entry into national phase |
Ref document number: 12666198 Country of ref document: US |
|
NENP | Non-entry into the national phase |
Ref country code: DE |