JP4936469B2 - Communications system - Google Patents

Description

  The present invention relates to a communication system used for crime prevention equipment, disaster prevention equipment, lighting equipment, and the like.

  Conventionally composed of crime prevention equipment consisting of human detection sensors and alarm devices, disaster prevention equipment consisting of temperature sensors, vibration sensors, alarm devices, etc., switch elements that turn on human detection sensors, lighting equipment and lighting equipment, etc. 2. Description of the Related Art A communication system that performs communication between nodes using a device such as a human sensor as a node is provided in an installation type facility such as a lighting facility. In a communication system used for such equipment, a transmission source node transmits a transmission packet including instructions and information to one or a plurality of nodes, and after transmission, the success or failure of reception of the transmission packet of each node, Communication is performed to confirm responses to information and information.

  Such communication methods include a communication method (for example, refer to Patent Document 1) in which a transmission source node individually performs unicast communication with a node that has received a transmission packet, and a node that has received the transmission packet. There is provided a communication method (see, for example, Patent Document 2) for confirming a reply packet including a response to a transmission packet and a reply packet including an acknowledgment (ACK) or a negative acknowledgment (NACK) to the transmission source node.

  Of the two communication methods described above, the communication method in which the transmission source node individually performs unicast communication with the node that has received the transmission packet requires a communication time corresponding to the number of nodes that have received the transmission packet. There is a problem that the communication time becomes long when the number of the previous nodes is large. In a communication system used for lighting equipment, since it is required that all lighting fixtures are turned on almost simultaneously after operating a switch element, a communication method that requires a long time for lighting confirmation is not desirable. If a high-speed communication system can be realized as a communication system, the communication time can be shortened. However, since the capital investment cost increases, it is still not desirable to introduce it into an installation-type facility such as a house. Therefore, in a communication system used for lighting equipment, it is desirable to employ a communication method in which a node that has received a transmission packet returns a reply packet to a transmission source node.

  On the other hand, the communication method in which the transmission source node transmits a transmission packet to the transmission destination node includes unicast communication in which the transmission packet is individually transmitted to each transmission destination node and transmission to the transmission destination node at one time. Multicast communication and broadcast communication are performed, but unicast communication transmits a transmission packet to each destination node individually, so a transmission time corresponding to the number of destination nodes is required and communication takes time. In addition, since all nodes receive transmission packets in broadcast communication, the number of return packets increases and communication takes time. Therefore, in a communication system used for the lighting equipment as described above, it is desirable to use multicast communication for transmission of transmission packets.

By the way, the transmission source node as described above transmits a transmission packet to a plurality of nodes at the same time using multicast communication or the like, and the node receiving the transmission packet returns a reply packet including an acknowledgment to the transmission source node. In the communication to be performed, there is a problem that a collision (collision) between reply packets occurs and the source node cannot normally receive the reply packet. To solve this problem, perform a collision check before replying a reply packet. If a collision is confirmed, check the collision again after the set waiting time has elapsed, and return a reply packet if no collision is confirmed. Technology is provided.
JP 2005-136881 PR JP-A-7-303111

  However, in the collision confirmation method, each node that returns a reply packet performs a collision confirmation, and when a collision is confirmed, the collision confirmation is performed again after the set waiting time has elapsed. There is a problem that it takes a long time to reply.

  The present invention has been made in view of the above reasons, and an object of the present invention is to provide a communication system capable of reducing the occurrence of collision between reply packets and shortening the communication time without performing collision confirmation.

The invention of claim 1 comprises a plurality of nodes each having its own unique address and multicast address as its own address, and the source node multicasts a transmission packet including a multicast address that determines a destination node. A node that transmits by communication and has a multicast address that is the same as the multicast address included in the transmission packet receives the transmission packet and creates a reply packet. The transmission packet is generated in the order of the number of nodes that reply the reply packet. The generated value is included, and the node returning the reply packet calculates the remainder by dividing its own unique address by the generated value acquired from the transmission packet, and performs an operation of multiplying the calculated remainder and a predetermined basic unit time. Is used to calculate the reply waiting time and Time is returned in unicast communication in the source node a reply packet when a reply waiting time, the source node may not receive the reply packet containing the acknowledgment of the node to be returned reply packets The reply node information including the unique address of the received node is modified to be included in the transmission packet, the modified transmission packet is retransmitted by multicast communication, and the node that has received the transmission packet receives the unique address contained in the reply node information and its own address. If the unique address matches, a reply packet is created and returned, and the source node returns the reply packet to the retransmitted send packet with the unique address included in the reply node information in the send packet. Change to the unique address of the node that was not able to receive the reply packet including the positive response among the power nodes It was modified, and the modifications to modify the generated value generated value generated again after generating again to a larger value, and wherein the retransmitting again transmit packet modified in multicast communication.

The invention of claim 2 comprises a plurality of nodes each having its own unique address and multicast address as its own address, and the transmission source node multicasts a transmission packet including a multicast address that determines a destination node. A node that transmits by communication and has a multicast address that is the same as the multicast address included in the transmission packet receives the transmission packet and creates a reply packet. The transmission packet is generated in the order of the number of nodes that reply the reply packet. The generated value is included, and the node returning the reply packet calculates the remainder by dividing its own unique address by the generated value acquired from the transmission packet, and performs an operation of multiplying the calculated remainder and a predetermined basic unit time. Is used to calculate the reply waiting time and Time is returned in unicast communication reply packet to the source node when it becomes a reply waiting time, the the transmission packet includes reply node information including the unique address of the node to be returned the reply packet, transmission The node that received the packet creates a reply packet when the unique address included in the reply node information matches its own unique address, and returns the reply packet, which is calculated from the reply packet sent back in the past by the sending node. The reply node information including the unique address of the node having a high success rate is included in the transmission packet and transmitted by multicast communication .

According to a third aspect of the present invention, in the second aspect of the present invention, each of the nodes includes a list storage unit that stores a priority list in which other nodes are ranked, and the source node is a node to which a reply packet should be returned In the node that could not receive the reply packet including the acknowledged response, the reply node information including only the unique address of the node having the highest priority in the priority list is included in the transmission packet and retransmitted by multicast communication. And

The invention of claim 4 comprises a plurality of nodes each having its own unique address and multicast address as its own address, and the source node multicasts a transmission packet including a multicast address that determines a destination node. A node that transmits by communication and has a multicast address that is the same as the multicast address included in the transmission packet receives the transmission packet and creates a reply packet. The transmission packet is generated in the order of the number of nodes that reply the reply packet. The generated value is included, and the node returning the reply packet calculates the remainder by dividing its own unique address by the generated value acquired from the transmission packet, and performs an operation of multiplying the calculated remainder and a predetermined basic unit time. Is used to calculate the reply waiting time and Time is returned in unicast communication reply packet to the source node when it becomes a reply waiting time, the return packet receiving node creates a transmission packet contains the address contained in the transmission packet Each node monitors reply packets sent back by other nodes, and if the address contained in the reply packet matches the address it owns and if it does not send back the reply packet, a negative response is included. A reply packet is created and transmitted to the transmission source node.

According to the configuration of the first aspect of the present invention, even when transmission packets are transmitted to a plurality of nodes at the same time using multicast communication, each destination node sends a reply packet after the reply waiting time calculated by each node has elapsed. Since each reply is made, collision between reply packets can be reduced. In addition, since the reply waiting time is calculated using the generated value generated from the number of destination nodes, the time until all reply packets are returned when the number of destination nodes is small is shortened. It is Ru can.

Further, it is possible to re-transmit the node to reply only a reply packet required node of a transmission packet, Ru can reduce the occurrence of collision between reply packet by reducing the number of reply packets.

Furthermore , when the transmission packet is retransmitted again, the remainder value calculated by each node can be changed by changing the generated value to a larger value, thereby reducing collisions between reply packets. Therefore, it is possible to provide a communication system that can shorten the communication time between the transmission source node and the transmission destination node .

According to the configuration of the invention of claim 2 , even when transmission packets are transmitted to a plurality of nodes simultaneously using multicast communication, each destination node sends a reply packet after the reply waiting time calculated by each node has elapsed. Since each reply is made, collision between reply packets can be reduced. In addition, since the reply waiting time is calculated using the generated value generated from the number of destination nodes, the time until all reply packets are returned when the number of destination nodes is small is shortened. Can do. In addition, since the number of nodes that send back reply packets can be reduced by limiting the nodes that send back reply packets using unique addresses, it is possible to reduce the number of reply packets and reduce the occurrence of collision between reply packets. it can. Furthermore, since a node that has a high probability of receiving a reply packet including an acknowledgment is a node that returns a reply packet, the probability that the transmission source node receives a reply packet including an acknowledgment increases. Therefore, it is possible to provide a communication system that can shorten the communication time between the transmission source node and the transmission destination node .

According to the configuration of the invention of claim 3 , among the nodes that need to retransmit the transmission packet, only the node with the highest priority in the priority list can be set as the node that returns the reply packet. It is possible to provide a communication system in which a transmission source node can receive a reply packet from the highest node without occurrence of a collision.

According to the configuration of the invention of claim 4 , even when transmission packets are transmitted to a plurality of nodes at the same time using multicast communication, each destination node transmits a reply packet after the reply waiting time calculated by each node has elapsed. Since each reply is made, collision between reply packets can be reduced. In addition, since the reply waiting time is calculated using the generated value generated from the number of destination nodes, the time until all reply packets are returned when the number of destination nodes is small is shortened. Can do. Therefore, it is possible to provide a communication system that can shorten the communication time between the transmission source node and the transmission destination node. In addition, a node that cannot receive a transmission packet and cannot recognize the presence of the transmission packet can recognize the presence of the transmission packet, and also transmits a reply packet including a negative response to the transmission source node. It is possible to provide a communication system that can request retransmission of a transmission packet to other nodes.

  In each of the following embodiments, a contention type multicast communication system will be described as an example, but a polling type communication system may be used. Each node includes a computer that realizes the following operations together with a communication function.

(Embodiment 1)
In this embodiment, as shown in FIG. 1, the transmission source node A transmits a transmission packet to the three nodes B1, B2, and B3 by multicast communication, and the three nodes B1 and B2 that have received the transmission packet, respectively. , B3 will be described by way of example of a communication system in which a reply packet is sent back to the transmission source node A by unicast communication.

  The source node A has the multicast addresses of the three nodes B1, B2 and B3, its own unique address, transmission data composed of commands and information desired to be transmitted, and the number N of nodes to which reply packets are returned. = 3 A transmission packet including the generated value M = N generated from 3 is created and transmitted by multicast communication (P11). Three nodes B1, B2, and B3 having the same multicast address as the multicast address included in the transmission packet each receive the transmission packet. The three nodes B1, B2, and B3 that have received the transmission packet send a reply packet including the unique address of the source node A, its own unique address, an acknowledgment or a negative response, and response data for the transmission data. A reply waiting time until each reply packet is created is calculated (P12), and the reply packets are transmitted to the source node in order from the node whose elapsed time after receiving the transmission packet becomes the reply waiting time. (P13, P14, P15).

Next, the operation of a node other than the transmission source node will be described in detail with reference to the flowchart of FIG. Each node determines whether the multicast address included in the transmission packet matches the multicast address that it owns (S11), and if it matches, receives the transmission packet (S12). The node that has received the transmission packet obtains the generated value M included in the transmitted packet (S13), calculates its remainder by dividing its own unique address by the generated value M, and the calculated remainder is predetermined. The reply waiting time is calculated by multiplying the basic waiting time (S14).
Thereafter, it is determined whether or not the elapsed time after reception of the transmission packet has become the reply standby time (S15), and when the elapsed time reaches the reply standby time, the reply packet is returned to the transmission source node by unicast communication ( S16). Note that the basic standby time is a time set in advance in each node based on the time required for reply packet reply, and is set to be approximately the same as the time required for reply packet reply in this embodiment.

  In this embodiment, the unique addresses of the three nodes B1, B2, and B3 are 1, 2, and 3, respectively, and the generated value M = N = 3. The reply waiting time to be calculated is 0 for the basic waiting time, twice the basic waiting time, and 0, respectively. Therefore, the node B3 returns a reply packet first, then the node B1 returns a reply packet, and finally the node B2 returns a reply packet.

  As described above, in this embodiment, transmission packets are simultaneously transmitted to a plurality of nodes using multicast communication. Each destination node returns a reply packet after the reply waiting time calculated by each node has elapsed. Therefore, collision between reply packets can be reduced. Further, since the reply waiting time is calculated using the generated value M = N generated from the number N of nodes that reply to the reply packet, all reply packets are returned when the number of nodes that reply the reply packet is small. Can be shortened. Further, by setting the basic unit time to be approximately the same as the time required for reply packets, it is possible to avoid collision of reply packets sent back by nodes that have calculated different reply waiting times. Therefore, a communication system that can shorten the communication time can be provided.

  In the present embodiment, the generated value M is the same as the number N of nodes that return reply packets, but the generated value M can be made larger than the number N to further reduce collisions between reply packets.

(Embodiment 2)
In this embodiment, as shown in FIG. 3, the source node A transmits a transmission packet to the three nodes B1, B2, and B3 by multicast communication, and the two nodes B1 and B2 are the source node A. An example of a communication system that returns a reply packet by unicast communication will be described.

  The source node A concatenates the multicast addresses of the three nodes B1, B2, and B3, its own unique address, the number of nodes to which the reply packet should be returned, and the unique addresses of the two nodes B1 and B2. Return node information composed of data, information indicating that return node information is included in the transmission packet, transmission data, and a generated value M = N generated from the number N = 2 of nodes that return the return packet. A transmission packet including the packet is created and transmitted by multicast communication (P21). The three nodes B1, B2, and B3 having the same multicast address as the multicast address included in the transmission packet receive the transmission packet and recognize the return node information from the information indicating that the transmission packet includes the return node information. The unique addresses B1 and B2 of the node to which the reply packet is to be returned are recognized from the number of nodes to which the reply packet included in the reply node information is to be returned and the data obtained by concatenating the unique address. The two nodes B1 and B2 having the same unique address as the recognized unique address respectively create reply packets. The two nodes B1 and B2 respectively calculate reply waiting times (P22), and send reply packets to the sending node A by unicast communication after the reply waiting time has elapsed (P23 and P24).

  In this embodiment, the transmission packet has information indicating that the reply packet includes reply node information. However, the transmission packet always has a reply packet, and the transmission packet includes reply node information. The information indicating that the transmission packet is not included can be used.

  As described above, according to the present embodiment, the transmission source node can reduce the number of nodes to which the return packet is returned by including the return node information including the unique address of the node to which the return packet is returned in the transmission packet. . Therefore, it is possible to provide a communication system that can reduce the number of reply packets and shorten the communication time.

(Embodiment 3)
In the present embodiment, as shown in FIG. 4, in addition to the communication system of the first embodiment, the transmission source node A retransmits a transmission packet to the three nodes B1, B2, and B3 by multicast communication, A communication system in which the nodes B1 and B3 return reply packets to the transmission source node A by unicast communication will be described as an example.

  The reply packets sent back by the two nodes B1 and B3 contain a negative response, the reply packets sent back by the node B2 contain an acknowledgment, and the source node A that received each reply packet has two Nodes B1 and B3 are determined as nodes that require retransmission of the transmission packet (P31). The source node A indicates that reply node information including the number of nodes to which reply packets are returned and data obtained by concatenating the unique addresses of the two nodes B1 and B3, and that the reply node information is included in the transmission packet. Information is included in the transmission packet, and the generated value M is generated again (M = N = 2) to correct the generated value included in the transmission packet, and the corrected reply packet is retransmitted by multicast communication. (P32). The three nodes B1, B2, and B3 having the same multicast address as the multicast address included in the transmission packet receive the transmission packet, respectively, and return node information in the three nodes B1, B2, and B3 that have received the transmission packet. Two nodes B1 and B3 having the same unique address as the included unique address respectively create a reply packet. The two nodes B1 and B3 that created the reply packet each calculate a reply waiting time (P33), and return the reply packet to the source node A by unicast communication after the reply waiting time has elapsed (P34, P35).

  In the communication system of the present embodiment, as described above, the transmission source node includes the return node information including the unique address of the node that needs to retransmit the transmission packet in the transmission packet. It is possible to reduce the number of nodes that return reply packets. Therefore, it is possible to provide a communication system that can reduce the occurrence of collision between reply packets and shorten the communication time.

(Embodiment 4)
In the present embodiment, as shown in FIG. 5, in addition to the communication system of the third embodiment, the transmission source node A retransmits the transmission packet to the three nodes B1, B2, and B3 again by multicast communication. A communication system in which the nodes B1 and B3 return reply packets to the transmission source node A by unicast communication will be described as an example.

  Of the three nodes B1, B2, and B3 that have received the retransmitted transmission packet, the unique addresses of the two nodes B1 and B3 that send back the reply packet are 1, 3, and the generated value M = N = 2. is there. Accordingly, the remainders calculated by the two nodes B1 and B3 are both 1, and the reply waiting times calculated by the two nodes B1 and B3 are the same, and the reply packets collide with each other. The transmission source node A cannot receive the reply packet returned by the two nodes B1 and B3 in response to the retransmitted transmission packet, and the two nodes B1 and B3 cannot receive the reply packet again. It is determined that the node needs to be retransmitted (P41). In the reply node information, the source node A performs a modification for changing the number of nodes to which reply packets should be returned and a modification for changing the unique addresses of the nodes B1 and B3 to the unique addresses of the two nodes B1 and B3. The generation value M is newly generated (M = N = 2), the newly generated generation value M is changed to a larger value (M = N + 1 = 3), and the generation value M included in the transmission packet is changed. Is modified to the generated value M changed, and the modified transmission packet is retransmitted again (P42). The three nodes B1, B2, and B3 having the same multicast address as the multicast address included in the transmission packet receive the transmission packet, respectively, and return node information in the three nodes B1, B2, and B3 that have received the transmission packet. The two nodes B1 and B3 having the same unique address as the included unique address respectively create a reply packet and calculate a reply waiting time (P43). Here, since the unique addresses of the two nodes B1 and B3 are 1 and 3, respectively, and the generated value M = 3, the remainders calculated by the two nodes B1 and B3 are 1 and 0, respectively. The reply waiting times calculated by the nodes B1 and B3 are the basic waiting time and 0, respectively. Therefore, the node B3 first returns a reply packet (P44), and then the node B1 returns a reply packet (P45).

  As described above, in the communication system according to the present embodiment, when retransmitting a transmission packet, the generated value M = N + 1 is set, the remainder value calculated by the node that returns the return packet is changed, and collision between the return packets is detected. It is decreasing. Therefore, it is possible to provide a communication system that can shorten the communication time.

  In the present embodiment, the generation value M is changed to be increased by 1. However, the present invention is not limited to this.

(Embodiment 5)
In this embodiment, as shown in FIG. 6, the transmission source node A transmits a transmission packet to the three nodes B1, B2, and B3 by multicast communication, and the two nodes B1 and B2 transmit the return packet. An example of a communication system that replies to each node A by unicast communication will be described.

  The transmission source node A calculates a reception success rate for receiving a reply packet including an acknowledgment for each of the other nodes from the reply packets received in the past, and sets the two nodes B1 and B2 having a high reception success rate. Selection, reply node information including the multicast addresses of the three nodes B1, B2, and B3, the number of nodes to which reply packets should be returned, and data concatenating the unique addresses of the two nodes B1 and B2, and transmission Create a transmission packet that includes information indicating that the reply node information is included in the packet, its own unique address, transmission data, and the generated value M = N generated from the number N = 2 of nodes that reply to the reply packet Then, it transmits by multicast communication (P51). The three nodes B1, B2, and B3 having the same multicast address as the multicast address included in the transmission packet receive the transmission packet, respectively, and return node information in the three nodes B1, B2, and B3 that have received the transmission packet. Two nodes B1 and B2 having the same unique address as the included unique address respectively create a reply packet. The two nodes B1 and B2 that have created the reply packet each calculate a reply waiting time (P52), and return the reply packet to the transmission source node A by unicast communication after the reply waiting time has elapsed (P53, P54). ).

  As described above, according to the communication system of the present embodiment, a node having a high probability of receiving a reply packet including an acknowledgment is a node that sends back a reply packet. The probability of receiving a reply packet including an affirmative response increases. Therefore, a communication system that can shorten the communication time can be provided.

  In the communication system according to the present embodiment, two nodes are selected from nodes having a high reception success rate, but the number is not limited to two.

(Embodiment 6)
In the present embodiment, as shown in FIG. 7, in addition to the communication system of the third embodiment, the transmission source node A retransmits the transmission packet to the three nodes B1, B2, and B3 by multicast communication, and the node B1 A communication system that returns a reply packet to the transmission source node A by unicast communication will be described as an example.

  Of the three nodes B1, B2, and B3 that have received the retransmitted transmission packet, the unique addresses of the two nodes B1 and B3 that send back the reply packet are 1, 3, and the generated value M = N = 2. is there. Accordingly, the remainders calculated by the two nodes B1 and B3 are both 1, and the reply waiting times calculated by the two nodes B1 and B3 are the same, and the reply packets collide with each other. The transmission source node A cannot receive the reply packets returned by the two nodes B1 and B3 in response to the retransmitted transmission packet, and the two nodes B1 and B3 are retransmitted again. It is determined that the node needs to be transmitted (P61). The node A of the transmission source ranks in the priority list in which the nodes stored in the list storage unit provided in the built-in storage unit are ranked among the two nodes B1 and B3 that need to retransmit the transmission packet. A node B1 having a higher value is selected, and in the reply node information, a modification for changing the number of nodes to which reply packets are to be returned and a modification for changing the unique address to the unique address of the node B1 are performed, and a generation value M is newly generated. (M = N = 1), the generated value M included in the transmission packet is corrected to the newly generated value M, and the corrected transmission packet is retransmitted again by multicast communication (P62). The three nodes B1, B2, and B3 having the same multicast address as the multicast address included in the transmission packet receive the transmission packet, respectively, and return node information in the three nodes B1, B2, and B3 that have received the transmission packet. Node B1 having the same unique address as the included unique address creates a reply packet. The node B1 that created the reply packet calculates a reply waiting time (P63), and returns the reply packet to the source node A by unicast communication after the reply waiting time has elapsed (P64).

  As described above, in the communication system of the present embodiment, among the nodes that need to retransmit the transmission packet, only the node with the highest priority in the priority list returns the reply packet. The transmission source node can reliably receive a reply packet from the node with the highest priority.

  Note that, after receiving the reply packet including the acknowledgment from the node B1, the source node A changes the unique address included in the reply node information to the unique address of the next highest priority node B3 and performs multicast communication. The transmitted packet can be retransmitted again.

(Embodiment 7)
In this embodiment, as shown in FIG. 8, the source node A transmits a transmission packet to the three nodes B1, B2, and B3 by multicast communication, and the node B3 transmits a return packet by unicast communication. A communication system that returns to node A will be described as an example.

  The source node A is a reply node including the multicast addresses of the three nodes B1, B2, and B3, the number of nodes to which reply packets should be returned, and data concatenating the unique addresses of the two nodes B1 and B3. Multicast communication by creating a transmission packet including information, information indicating that the return packet information is included in the transmission packet, transmission data, and a generated value M = N generated from the number N = 2 of nodes to be received (P71). The two nodes B2 and B3 having the same multicast address as the multicast address included in the transmission packet receive the transmission packet, but the node B1 transmits the transmission packet due to accidental noise or a temporary failure of the packet reception circuit. Is unable to receive. Of the two nodes B2 and B3 that have received the transmission packet, the node B3 having the same unique address as the unique address included in the reply node information is the unique address of the source node A, its own unique address, and an acknowledgment. Alternatively, a reply packet including a negative response and the unique address included in the reply node information is created and a reply waiting time is calculated (P72). After the reply waiting time elapses, the transmission source node A performs unicast communication. A reply packet is returned (P73). The node B1 monitors the reply packet sent back by the node B3, determines whether the unique address contained in the reply packet sent back by the node B3 matches its own unique address, and sends the reply packet to the source node A. Is already returned (P74). The node B1 that has determined that the unique address included in the reply packet returned by the node B3 matches its own unique address and has not returned the reply packet to the source node A, returns a reply packet including a negative response. Is transmitted to the source node A by unicast communication (P75).

  As described above, in the communication system according to the present embodiment, the transmission packet cannot be received due to the occurrence of accidental noise or the temporary failure of the reception circuit that receives the transmission packet, and the presence of the transmission packet cannot be recognized. Provided is a communication system in which a node can know the existence of a transmission packet, and can request the transmission source node to retransmit the transmission packet by transmitting a reply packet including a negative response to the transmission source node. it can.

  If the reply node information is not included in the transmission packet, the node B3 includes not the unique address but the multicast address included in the transmission packet, and the node B1 returns the reply packet returned by the node B3. It is also possible to determine whether or not the multicast address included in the URL matches its own multicast address.

  Moreover, in each embodiment mentioned above, although the communication system which performs communication between four nodes was illustrated, it is not restricted to this, What is necessary is just two or more nodes. If the source node is always a specific node, the transmission packet may not include its own unique address, and the reply packet may not include the transmission source node's unique address.

FIG. 6 is a diagram illustrating an operation of the first embodiment. It is a flowchart showing operation | movement of nodes other than a transmission source node same as the above. FIG. 10 is a diagram illustrating an operation of the second embodiment. FIG. 10 is a diagram illustrating an operation of the third embodiment. It is a figure which shows operation | movement of Embodiment 4. FIG. 10 is a diagram illustrating the operation of the fifth embodiment. FIG. 10 is a diagram illustrating the operation of the sixth embodiment. FIG. 10 is a diagram illustrating the operation of the seventh embodiment.

Explanation of symbols

A node B1 node B2 node B3 node

Claims (4)

It consists of a plurality of nodes each having its own unique address and multicast address as its own address, and the transmission source node transmits a transmission packet including the multicast address that determines the destination node by multicast communication. A node having the same multicast address as the multicast address included in the packet receives the transmission packet and creates a reply packet. The transmission packet includes a generated value generated in the order of the number of nodes that reply the reply packet. The node that returns the packet calculates the remainder by dividing its own unique address by the generated value obtained from the transmission packet, and calculates the reply waiting time using an operation that multiplies the calculated remainder and a predetermined basic unit time. And the elapsed time after receiving the transmission packet is waiting for a reply Reply with unicast communication reply packet to the source node when it becomes,
The source node modifies the transmission packet to include the reply node information including the unique address of the node that could not receive the reply packet including the acknowledgment among the nodes to which the reply packet should be returned. The node that retransmits by multicast communication and receives the transmission packet creates a reply packet when the unique address included in the reply node information matches its own unique address,
The transmission source node, in the transmission packet, the unique address included in the reply node information of the node that could not receive the reply packet including the acknowledgment among the nodes that should reply the reply packet to the retransmitted transmission packet A communication that is modified to change to a unique address, regenerates the generated value, then changes the generated value again to a larger value, and retransmits the corrected transmission packet again by multicast communication. system. It consists of a plurality of nodes each having its own unique address and multicast address as its own address, and the transmission source node transmits a transmission packet including the multicast address that determines the destination node by multicast communication. A node having the same multicast address as the multicast address included in the packet receives the transmission packet and creates a reply packet. The transmission packet includes a generated value generated in the order of the number of nodes that reply the reply packet. The node that returns the packet calculates the remainder by dividing its own unique address by the generated value obtained from the transmission packet, and calculates the reply waiting time using an operation that multiplies the calculated remainder and a predetermined basic unit time. And the elapsed time after receiving the transmission packet is waiting for a reply Reply with unicast communication reply packet to the source node when it becomes,
The transmission packet includes reply node information including a unique address of a node to which a reply packet should be returned, and the node that has received the send packet has a unique address included in the reply node information and its own unique address match Create a reply packet and reply ,
Source node communication system that is characterized in that the return node information included in the transmission packet transmitted in the multicast communication including the unique address of the higher node reception success rate calculated from the returned reply packet in the past . Each of the nodes includes a list storage unit that stores a priority list in which other nodes are ranked, and the transmission source node is a node that has not received a reply packet including an acknowledgment among the nodes to which the reply packet should be returned. The communication system according to claim 2 , wherein reply node information including only the unique address of the node having the highest priority in the priority list is included in the transmission packet and retransmitted by multicast communication . It consists of a plurality of nodes each having its own unique address and multicast address as its own address, and the transmission source node transmits a transmission packet including the multicast address that determines the destination node by multicast communication. A node having the same multicast address as the multicast address included in the packet receives the transmission packet and creates a reply packet. The transmission packet includes a generated value generated in the order of the number of nodes that reply the reply packet. The node that returns the packet calculates the remainder by dividing its own unique address by the generated value obtained from the transmission packet, and calculates the reply waiting time using an operation that multiplies the calculated remainder and a predetermined basic unit time. And the elapsed time after receiving the transmission packet is waiting for a reply Reply with unicast communication reply packet to the source node when it becomes,
The reply packet created by the node that received the transmission packet includes the address included in the transmission packet, and each node monitors the reply packet returned by the other node, and the address included in the reply packet self of the address included in the match and, if not returns the reply packet, communication system you characterized in that create and send reply packet to the source node including a negative response.

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