Multicast communication method, multicast communication system, node device and chip

Abstract

The present invention relates to the field of communication, and discloses a multicast communication method, a multicast communication system, a node device, and a chip. The multicast communication method comprises: receiving a multicast message, wherein the multicast message comprises: a mapping relationship between a device group, a multicast group number, and an identifier of a device in the device group; determining the multicast group number to which the slave node device belongs according to the mapping relationship and the slave node device identifier; in response to a group control message carrying a multicast group number sent by a master node device, receiving the group control message, and when the multicast group number of the slave node device is the same as the target multicast group number, performing a control operation on the corresponding terminal device according to the control instruction in the group control message to obtain a response message; and uploading the response message. The present invention can at least solve some or all of the problems existing in the prior art. It sends the same message in a multicast manner, which can reduce repeated sending of the same message and reduce bandwidth resource occupation.

Description

Technical Field

[0001] The present invention relates to the field of communications, and in particular to a multicast communication method, a multicast communication system, a node device and a chip. Background Art

[0002] The advantages of HPLC (High-speed power line carrier) communication include using existing power lines without laying new communication lines, reducing costs and covering a wide range; using digital communication technology, fast transmission speed and low bit error rate; improving safety and reliability through remote monitoring, etc. However, it also has some disadvantages, including being susceptible to interference, such as lightning and electromagnetic interference, which will reduce transmission quality and efficiency, and being greatly affected by the environment. The length, voltage, current, impedance, etc. of the wire will affect the transmission of the signal, and the noise on the power line will also affect the transmission of the signal. Therefore, in some environments, the signal transmission will be unstable, which will have a negative impact on the success rate and delay of data acquisition.

[0003] like Figure 1 As shown in the figure, in the communication network that uses power lines as the communication medium for data transmission, the CCO is first used as the root node, and a multi-level tree structure network is formed with each slave node. Then, the CCO sends control or data acquisition instructions to the STA to maintain the interaction process. In this process, the CCO interacts with each STA individually, that is, one-to-one interaction.

[0004] like Figure 1 As shown, the existing dual-mode data communication services have the following characteristics:

[0005] (1) A downlink frame needs to be sent to each node for reading;

[0006] (2) CCO interacts with multiple STAs in a concurrent manner. Due to bandwidth limitations, the number of concurrent operations is limited (the ideal number of concurrent operations is 5-20). When there are many nodes to be operated at the same time, multiple rounds are required, during which the next round of tasks must be executed after the previous round of tasks is completed.

[0007] The current power system usually monitors users by daily freezing, monthly freezing, 96-point curves, etc., and these tasks are all based on concurrent reading. When executing the above tasks, it is usually necessary to perform multiple rounds. During this period, it is necessary to wait for the previous round of tasks to be completed before executing the next round of tasks. This will occupy link resources for a long time. If there is environmental interference, the delay will be even longer.

[0008] As the number of households connected to distributed photovoltaics increases day by day, the capacity of the low-voltage household photovoltaic grid-connected power grid increases sharply, which may cause the voltage in the substation to be too high. The substation cannot consume the photovoltaic output locally, and a large amount of photovoltaic power generation is fed back, causing some low-voltage substation transformers to form reverse heavy overloads, and then forming a regional 10kV line power back to the 110kV line. There have even been full backflows at 330kV substations. This phenomenon will seriously affect the safe production of the power grid, so it is necessary to carry out more efficient and real-time regulation of these key users.

[0009] In summary, on the one hand, HPLC communication itself may have unstable signal transmission in certain environments, resulting in a success rate of less than 100% or a large delay; on the other hand, the current concurrent technology occupies more bandwidth resources for a long time. Summary of the invention

[0010] The purpose of the present invention is to provide a multicast communication method, a multicast communication system, a node device and a chip, which can at least solve some or all of the problems existing in the prior art. By sending the same message in a multicast manner, the repeated sending of the same message can be reduced, and the bandwidth resource occupation can be reduced.

[0011] In order to achieve the above-mentioned purpose, the first aspect of the present invention provides a multicast communication method, which is executed by a slave node device, and the multicast communication method includes: receiving a multicast message, wherein the multicast message includes: a mapping relationship between a device group, a multicast group number of the device group, and an identifier of a device in the device group; determining the multicast group number to which the slave node device belongs according to the mapping relationship and the identifier of the slave node device; in response to a master node device sending a group control message carrying the same multicast group number, receiving the group control message, and determining whether the multicast group number of the slave node device is the same as a target multicast group number carried by the group control message; when the multicast group number of the slave node device is the same as the target multicast group number, performing a corresponding control operation on the corresponding terminal device according to the control instruction in the group control message to obtain a response message, wherein the response message includes the execution result of the corresponding control operation; and uploading the response message.

[0012] Through the above technical scheme, the present invention creatively completes grouping through the slave node device according to the mapping relationship in the multicast message and the identifier of the slave node device, and then, in response to the master node device sending the same group control message, receives the group control message, and when the multicast group number of the slave node device is the same as the target multicast group number carried by the group control message, performs corresponding control operations on the corresponding terminal device according to the control instructions in the group control message to obtain a response message, and finally uploads the response message. It can at least solve some or all of the problems existing in the prior art. It sends the same message in a multicast manner, which can reduce the repeated sending of the same message and reduce the bandwidth resource occupation.

[0013] A second aspect of the present invention provides a multicast communication method, which is executed by a master node device, and the multicast communication method includes: sending a multicast message, wherein the multicast message includes: a mapping relationship between a device group, a multicast group number of the device group, and an identifier of a device in the device group; in response to a slave node device determining the multicast group number to which the slave node device belongs based on the mapping relationship and the identifier of the slave node device, sending a group control message carrying a target multicast group number; and in response to the slave node device determining that the multicast group number of the slave node device is the same as the target multicast group number, executing a control instruction in the group control message and uploading a response message corresponding to the group control message, receiving the response message.

[0014] Through the above technical scheme, the present invention creatively sends a multicast message through a master node device; in response to the slave node device completing the grouping according to the mapping relationship in the multicast message and the identifier of the slave node device, sends the same group control message; and in response to the slave node device determining that the multicast group number of the slave node device is the same as the target multicast group number carried by the group control message, executes the control instruction in the group control message and uploads a response message corresponding to the group control message, and receives the response message, which can at least solve some or all of the problems existing in the prior art. It sends the same message in a multicast manner, which can reduce the repeated sending of the same message and reduce the bandwidth resource occupation.

[0015] The third aspect of the present invention provides a multicast communication system, which is executed by a slave node device, and the multicast communication system includes: a receiving device, which is used to receive a multicast message, wherein the multicast message includes: a mapping relationship between a device group, a multicast group number of the device group, and an identifier of a device in the device group; a group number determination device, which is used to determine the multicast group number to which the slave node device belongs based on the mapping relationship and the identifier of the slave node device; a judgment device, which is used to receive the group control message in response to a master node device sending a group control message carrying the multicast group number, and judge whether the multicast group number of the slave node device is the same as the target multicast group number carried by the group control message; an execution device, which is used to perform a corresponding control operation on a corresponding terminal device according to a control instruction in the group control message when the multicast group number of the slave node device is the same as the target multicast group number, so as to obtain a response message, wherein the response message includes the execution result of the corresponding control operation; and an uploading device, which is used to upload the response message.

[0016] A fourth aspect of the present invention provides a multicast communication system, which is executed by a master node device, and the multicast communication system includes: a first sending device, used to send multicast messages, wherein the multicast message includes: a mapping relationship between a device group, a multicast group number of the device group, and an identifier of a device in the device group; a second sending device, used to respond to a slave node device determining the multicast group number to which the slave node device belongs based on the mapping relationship and the identifier of the slave node device, and send the same group control message carrying the target multicast group number; and a receiving device, used to respond to the slave node device determining that the multicast group number of the slave node device is the same as the target multicast group number, executing the control instruction in the group control message and uploading a response message corresponding to the group control message, and receiving the response message.

[0017] A fifth aspect of the present invention provides a slave node device, the slave node device comprising: an execution device for executing the multicast communication method.

[0018] A sixth aspect of the present invention provides a master node device, the master node device comprising: an execution device for executing the multicast communication method.

[0019] A seventh aspect of the present invention provides a computer-readable storage medium, on which a computer program is stored, and when the computer program is executed by a processor, the multicast communication method is implemented.

[0020] The eighth aspect of the present invention provides a chip, which includes: a processor; a memory for storing a computer program executed by the processor; the processor is used to read the computer program from the memory and execute the computer program to implement the multicast communication method.

[0021] A ninth aspect of the present invention provides a computer program product, comprising a computer program, which implements the multicast communication method when executed by a processor.

[0022] Other features and advantages of the present invention will be described in detail in the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The accompanying drawings are used to provide a further understanding of the embodiments of the present invention and constitute a part of the specification. Together with the following specific implementations, they are used to explain the embodiments of the present invention, but do not constitute a limitation on the embodiments of the present invention. In the accompanying drawings:

[0024] Figure 1 It is a schematic diagram of a tree structure network in an existing dual-mode data communication service;

[0025] Figure 2 is a flow chart of a multicast communication method provided by an embodiment of the present invention;

[0026] Figure 3 is a schematic diagram of a multicast communication process provided by an embodiment of the present invention;

[0027] Figure 4 is a schematic diagram of a multicast communication process provided by an embodiment of the present invention;

[0028] Figure 5 is a schematic diagram of a multicast communication process provided by an embodiment of the present invention;

[0029] Figure 6 is a schematic diagram of a multicast communication process provided by an embodiment of the present invention;

[0030] Figure 7 is a flow chart of a multicast communication method provided by an embodiment of the present invention; and

[0031] Figure 8 It is a schematic diagram of a time slot allocation strategy provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0032] The specific implementation of the present invention is described in detail below in conjunction with the accompanying drawings. It should be understood that the specific implementation described here is only used to illustrate and explain the present invention, and is not used to limit the present invention.

[0033] When the wireless communication system communicates, the CCO (Central Coordinator) needs to cooperate with the slave node device to form a network. Among them, the slave node device includes the proxy role PCO (ProxyCoordinator) and the non-proxy role STA (Station). In the networking process, the slave node device carries its own identification (such as a unique identification, through which the device type of the slave node device (such as photovoltaic equipment) can also be determined to facilitate user identification) to the networking request, and the CCO performs the corresponding networking process according to the networking request to form a network structure such as Figure 1 The multi-level tree structure network shown in the figure. The various embodiments of the present invention are based on the premise that the networking process has been completed.

[0034] Figure 2 FIG. 1 is a flow chart of a multicast communication method provided by an embodiment of the present invention. The multicast communication method is executed by a slave node device. Figure 2 As shown, the multicast communication method includes: step S201, receiving a multicast message, wherein the multicast message includes: a mapping relationship between a device group, a multicast group number of the device group, and an identifier of a device in the device group; step S202, determining the multicast group number to which the slave node device belongs according to the mapping relationship and the identifier of the slave node device; step S203, in response to a master node device sending a group control message carrying a multicast group number, receiving the group control message, and determining whether the multicast group number of the slave node device is the same as the target multicast group number carried by the group control message; step S204, when the multicast group number of the slave node device is the same as the target multicast group number, performing a corresponding control operation on the corresponding terminal device according to the control instruction in the group control message to obtain a response message, wherein the response message includes the execution result of the corresponding control operation; step S205, uploading the response message.

[0035] The following explains and illustrates each of the above steps.

[0036] Step S201: receiving a multicast message.

[0037] The multicast message includes: a device group, a multicast group number of the device group, and a mapping relationship between identifiers of devices in the device group.

[0038] Specifically, after the networking is completed, the CCO is aware of the specific conditions of each node in the networking network, and can configure multicast group numbers for slave node devices according to user requirements.

[0039] For example, the user specifies to query the meter reading results of STA2 and STA3, and query other results of STA3 and STA4 (for example, fee control (recharge) results, control (restart, power off) results, etc.). CCO can assign STA2 and STA3 to a device group 1 according to this requirement, and specify the corresponding multicast group number (for example, G1) for the device group 1. Figure 3 As shown in the figure; STA3 and STA4 are assigned to a device group 2, and a corresponding multicast group number (such as G2) is specified for the device group 2, which is not shown in the figure. CCO determines the following mapping relationships: device group 1--multicast group number G1--{STA2 and STA3}; device group 2--multicast group number G2--{STA3 and STA4}, etc. CCO can send the determined mapping relationship to the slave node devices (such as STA1, STA2, STA3, STA4).

[0040] For example, if the user specifies to query the meter reading results of STA2, STA3, and STA4, CCO can assign STA2, STA3, and STA4 to a device group according to the requirement, and specify the corresponding multicast group number (for example, G1) for the device group. Figure 4 As shown; similarly, other slave node devices are assigned to other device groups as needed. CCO determines the following mapping relationship: device group 1--multicast group number G1--{STA2, STA3, STA4}. CCO can send the determined mapping relationship to the slave node devices (such as STA1, STA2, STA3, STA4).

[0041] For example, if the user specifies to query the meter reading results of STA2, STA3, STA4, and PCO3, CCO can assign STA2, STA3, STA4, and PCO3 to a device group according to the requirement, and specify the corresponding multicast group number (for example, G1) for the device group. Figure 5 As shown; similarly, other slave node devices are assigned to other device groups as needed. CCO determines the following mapping relationship: device group 1--multicast group number G1--{STA2, STA3, STA4, PCO3}, and other mapping relationships are similar and are not listed here one by one. CCO can send the determined mapping relationship to the slave node devices (such as STA1, STA2, STA3, STA4, PCO3).

[0042] For example, if the user specifies to query the meter reading results of STA3 and STA4, CCO can assign STA3 and STA4 to a device group according to the requirement and specify the corresponding multicast group number (for example, G1) for the device group. Figure 6As shown; similarly, other slave node devices are assigned to other device groups as needed. CCO determines the following mapping relationship: device group 1--multicast group number G1--{STA3, STA4}, other mapping relationships are similar and are not listed here. CCO can send the determined mapping relationship to the slave node devices (such as STA1, STA2, STA3, STA4, STA5, STA6).

[0043] Step S202: Determine the multicast group number to which the slave node device belongs according to the mapping relationship and the identifier of the slave node device.

[0044] like Figure 3 As shown, for the slave node device identified as STA2, by querying the mapping relationship device group 1--multicast group number G1--{STA2, STA3}, it can be determined that the multicast group number to which the slave node device belongs is G1; for the slave node devices with other identifiers, a similar method is used to determine the multicast group number described by itself, which will not be described one by one here. In this way, the grouping process of the slave node device can be completed. When the user needs to query the node of G1, CCO can use G1 as the target group number, and carry the target group number G1 through the group control message (which includes the control instruction to query the meter reading results of STA2 and STA3), send the group control message to STA2 via PCO1, and send the group control message to STA3 via PCO2. Among them, the messages received by STA2 and STA3 are the same (the group control message includes the target multicast group number, but does not include the identification of each device in the group with the group number (that is, the destination device address)). The existing method needs to send two messages with different contents, for example, one message includes the destination device address of STA2, and the other message includes the destination device address of STA3. Different from the prior art, the two messages sent by the embodiment of the present invention are equivalent to one message, and the bytes occupied by the message are reduced, which can save bandwidth resources.

[0045] like Figure 4As shown, for the slave node device identified as STA2, by querying the mapping relationship device group 1--multicast group number G1--{STA2, STA3, STA4}, it can be determined that the multicast group number to which the slave node device belongs is G1; for slave node devices with other identifiers, a similar method is used to determine the multicast group number described by itself, which will not be described one by one here. In this way, the grouping process of the slave node device can be completed. When the user needs to query the node of G1, CCO can use G1 as the target group number, and carry the target group number G1 through the group control message (which includes the control instruction to query the meter reading results of STA2, STA3, and STA4), and send the group control message to STA2 and STA3 through PCO2, and send the group control message to STA4. Among them, the messages received by STA2, STA3, and STA4 are the same, and STA2 and STA3 share a communication path (some slave node devices in the same group share a communication path), and CCO sends a group control message (as shown by the green arrow) through the communication path (CCO--PCO2), which is different from the existing technology. The existing method needs to send two messages (as shown by the orange arrow, the destination device addresses of the two messages are different). In this embodiment, the multicast technology is used to reduce the repeated sending of the same message and reduce the bandwidth resource occupation.

[0046] like Figure 5As shown, for the slave node device identified as STA2, by querying the mapping relationship device group 1--multicast group number G1--{STA2, STA3, STA4, PCO3}, it can be determined that the multicast group number to which the slave node device belongs is G1; for slave node devices with other identifiers, a similar method is used to determine the multicast group number described by itself, which will not be described one by one here. In this way, the grouping process of the slave node device can be completed. When the user needs to query the node of G1, CCO can use G1 as the target group number, and carry the target group number G1 through the group control message (which includes the control instruction for querying the meter reading results of STA2, STA3, STA4, and PCO3), send the group control message to STA2 and STA3 via PCO2, send the group control message to PCO3, and send the group control message to STA4 via PCO3. Among them, the messages received by STA2, STA3, STA4, and PCO3 are the same, and STA2 and STA3 share a communication path (some slave node devices in the same group share a communication path), and CCO sends a group control message through the communication path (CCO--PCO2) (as shown by the green arrow); STA4 and PCO3 share a communication path (some slave node devices in the same group share a communication path), and CCO sends a group control message through the communication path (CCO--PCO3) (as shown by the green arrow). This is different from the prior art. The existing method requires sending two messages (as shown by the orange arrow, the destination device addresses of the two messages are different, one address is PCO3, and the other address is STA4). In this embodiment, multicast technology is used to reduce the repeated sending of the same message and reduce bandwidth resource usage.

[0047] like Figure 6 As shown, for the slave node device identified as STA2, by querying the mapping relationship device group 1--multicast group number G1--{STA3, STA4}, it can be determined that the multicast group number to which the slave node device belongs is G1; for the slave node devices with other identifiers, a similar method is used to determine the multicast group number described by itself, which will not be described one by one here. In this way, the grouping process of the slave node device can be completed. When the user needs to query the node of G1, CCO can use G1 as the target group number, and carry the target group number G1 through the group control message (which includes the control instruction to query the meter reading results of STA3 and STA4), and send a group control message to all slave node devices (STA3, STA4) in the same group through the common communication path of CCO--PCO2--PCO3 (as shown by the green arrow). This is different from the prior art. The existing method needs to send two messages (as shown by the orange arrow, the destination device addresses of the two messages are different). In this embodiment, the multicast technology can greatly reduce the repeated sending of the same message and reduce the bandwidth resource occupation.

[0048] Low communication delay: By reducing the repeated sending of downlink messages and reducing the waiting time for multiple rounds of execution, the overall communication delay is reduced and group scheduling and group control commands are responded to more quickly.

[0049] That is to say, when multiple slave node devices share a communication path, the CCO can send a group control message. Of course, the CCO can also include the group size, the level and role of the slave node device, control instructions, etc. in the group control message, and send the group control message in the above manner.

[0050] In step S202, group management and control of key customers are implemented through grouping technology. Group control can achieve flexible control and support more flexible group adjustment and control strategies.

[0051] Step S203, in response to the master node device sending the same group control message carrying the multicast group number, receiving the group control message, and determining whether the multicast group number of the slave node device is the same as the target multicast group number carried in the group control message.

[0052] In one embodiment, when the slave node device shares a communication path with other slave node devices and the slave node device and the other slave node devices belong to the same multicast group number, receiving the group control message includes: in response to the master node device sending a group control message carrying the target multicast group number through the communication path, receiving the group control message.

[0053] by Figure 3 For example, STA2 and STA3 receive the same group control message sent by CCO, wherein the group control message carries a multicast group number. Specifically, when PCO1 receives the group control message, since this node does not have a multicast group number, it does not process the group control message, but only forwards it. When STA2 receives the group control message, it determines whether its own group number is the same as the multicast group number carried by the group control message to determine whether to continue processing the group control message; forwards the group control message to STA3 via PCO2; when STA3 receives the group control message, it determines whether its own group number is the same as the multicast group number carried by the group control message to determine whether to continue processing the group control message; when STA4 receives the group control message, it determines whether its own group number is the same as the multicast group number carried by the group control message to determine whether to continue processing the group control message.

[0054] like Figure 4As shown, STA2, STA3, and STA4 receive the same group control message sent by CCO, wherein the group control message carries a multicast group number, and CCO can forward it to STA2 and STA3 via PCO2 by sending a group control message. Specifically, when PCO2 receives the group control message, since this node does not have a multicast group number, it does not process the group control message and only forwards it. When STA2 and STA3 receive the group control message, each determines whether its own group number is the same as the multicast group number carried by the group control message to determine whether to continue processing the group control message. CCO sends an identical group control message to STA4. When STA4 receives the group control message, each determines whether its own group number is the same as the multicast group number carried by the group control message to determine whether to continue processing the group control message.

[0055] like Figure 6 As shown, CCO can forward a group control message to STA3 and STA4 via PCO2 and PCO3 by sending it. Specifically, when PCO2 and PCO3 receive the group control message, since these two nodes do not have the multicast group number, they do not process the group control message but only forward it. When STA3 and STA4 receive the group control message, they each determine whether their own group number is the same as the multicast group number carried by the group control message to determine whether to continue processing the group control message.

[0056] Step S204, when the multicast group number of the slave node device is the same as the target multicast group number, a corresponding control operation is performed on the corresponding terminal device according to the control instruction in the group control message to obtain a response message.

[0057] Wherein, the response message includes the execution result of the corresponding control operation. If the control instruction is a meter reading instruction, the response message includes meter reading data.

[0058] The terminal device may be an electric meter, a rail meter, a collector, a water meter, a gas meter, or the like.

[0059] More specifically, the electric meter may include: single-phase electric meter, three-phase three-wire electric meter, three-phase four-wire electric meter and other electric meters classified by phase line, or industrial electric meter and civil electric meter, electronic standard meter, maximum demand measurement electric meter, single rate and multi-rate electric meter, prepaid electric meter, remote electric meter and other electric meters classified by function; the collector may include type I collector and type II collector. For example, the electric meter may be: an electric meter used in a photovoltaic network (can be referred to as a photovoltaic meter, such as Figure 2 PV meter 1, PV meter 2), or the electric meter used by ordinary users (which can be referred to as the electric meter, such as Figure 2 Meter 1 and Meter 2 in the diagram).

[0060] like Figure 3 As shown, when STA2 and STA3 respectively determine that the group number to which they belong is the same as the target group number, they process the group control message to obtain the control instructions, group size, and the level and role of the slave node device included in the group control message; and perform corresponding meter reading operations according to the meter reading instructions in the received group control message to obtain corresponding meter reading data.

[0061] The various figures of the present invention (for example Figure 3 ) is mainly demonstrated and explained by taking photovoltaic meters as an example, but the present invention is not limited to photovoltaic meters. Other types of electric meters, rail meters, collectors, water meters, or gas meters are all feasible, and the corresponding communication processes are the same or similar, which will not be repeated here. In addition, the terminal devices corresponding to all devices in the same device group (i.e., slave node devices) can be meters of the same type (for example, all photovoltaic meters) or different types of meters (for example, including electric meters, water meters, etc.).

[0062] Step S205, uploading the response message.

[0063] by Figure 3 For example, STA2 uploads the response message obtained in step S204 to CCO; STA3 uploads the response message obtained in step S204 to CCO.

[0064] In one embodiment, in addition to the above steps S201-S205, Figure 7 As shown, the multicast communication method also includes: step S206, determining the reporting time window according to the group size in the group control message, the level and role of the slave node device, and the transmission time of the uplink message; step S207, performing a random delay within the reporting time window within the bound CSMA time slot to obtain the reporting time; and step S208, uploading a response message when the reporting time arrives.

[0065] The above steps S206 to S208 are explained and illustrated below respectively.

[0066] Step S206: determining a reporting time window according to the group size in the group control message, the level and role of the slave node device, and the transmission time of the uplink message.

[0067] In one embodiment, for step S206, determining the reporting time window includes: , the hierarchy of the slave node device Load factor corresponding to the role , and the transmission time of the uplink message , the reporting time window T is determined by the following formula (1):

[0068]

[0069] in, , , are the minimum and maximum thresholds for group size, respectively; ; , , are the minimum and maximum values ​​of the level respectively; for The weight of .

[0070] For example, the multicast communication method further includes: determining the transmission time of the uplink message according to the size of the uplink message and the PB block size.

[0071] Specifically, determining the transmission time of the uplink message according to the size of the uplink message and the PB block size includes:

[0072] In the case of a PB block size of 72 bytes, ;

[0073] In the case of a PB block size of 136 bytes, ;

[0074] In the case of a PB block size of 264 bytes, ;as well as

[0075] In the case of a PB block size of 520 bytes, ,

[0076] Wherein, M is a positive integer, the size of the uplink message is x bytes, and f t The unit is ms. For example, when the PB block size is 72 bytes, when x is less than or equal to 72 bytes, f t = 1ms; when x is greater than 72 bytes and less than or equal to 144 bytes, f t =2ms.

[0077] For example, the multicast communication method further includes: determining the load factor by the following method: : In the case where the role of the slave node device is a proxy node, ; In the case where the role of the slave node device is STA, .

[0078] In another embodiment, determining the reporting time window further includes: In the case of, the reporting time window is determined to be 0, where N is the group size, is the minimum threshold of group size.

[0079] Accordingly, a random delay is performed within the reporting time window within the bound CSMA time slot to obtain the reporting time, including: determining the random delay time as 0 to determine the current time as the reporting time.

[0080] Specifically, multicast message discretization is mainly carried out at two levels.

[0081] 1. In the upper layer application, T (discrete time window or reporting time window) and uplink message size / uplink message transmission time are weightedly calculated based on group size, node level, node role, etc. The detailed calculation is shown in the above formula (1).

[0082] (1) Within a certain range ( ), as the group size N increases, the discrete reporting window time becomes longer. At the same time, considering the link capacity, when the group size N is small ( ), you can send it directly without waiting. , are the minimum and maximum thresholds for group size, respectively.

[0083] (2) Within a certain uplink message range (or ), as the size of the uplink message increases, the discrete reporting window time becomes longer, and the discrete reporting is mainly based on the PB block size. Within the PB range, it can be processed based on the following Table 1. When The values ​​are also positively correlated. , They are the maximum transmission time threshold and the minimum transmission time threshold respectively.

[0084] Table 1 Mapping of PB block size and time base

[0085] PB block size (bytes) Time base (ms) 72 1 136 2 264 3 520 4

[0086] (3) Within a certain range ( ), as the node level Increase, fewer nodes, smaller conflict probability, so the discrete reporting time can be appropriately shortened. , They are the minimum and maximum values ​​of the level respectively.

[0087] (4) For the proxy role, the load is relatively large, which increases the probability of conflict, so the discrete reporting time can be appropriately increased. In the case where the role of the slave node device is a proxy node, ; In the case where the role of the slave node device is STA, .

[0088] The above thresholds can be reasonably set according to actual application scenarios.

[0089] 2. On the underlying communication link, bind CSMA (Carrier Sense Multiple Access) time slots and perform hierarchical reservation management. By combining with the upper layer discrete, minimize service conflicts and improve channel utilization. See the following description for details. Figure 8 B-CSMA is used to represent it.

[0090] Step S207: Perform a random delay within the reporting time window within the bound CSMA time slot to obtain a reporting time.

[0091] The upper layer calculates the discrete time window based on the weights of group size, message size, node level, node role, etc., and then sends the message to the underlying communication link. The underlying link makes reservations by binding CSMA time slots and performs random discrete delays within the discrete time window (such as Figure 8 As shown in the figure), to reduce message conflicts and improve the communication success rate.

[0092] Step S208: uploading a response message when the reporting time arrives.

[0093] After the discrete delay expires, a response is sent to the CCO.

[0094] Specifically, the packet multicast communication process includes the following contents.

[0095] The first step is that when STA is networking, it carries its own device type (such as photovoltaic module) to facilitate user identification.

[0096] In the second step, after the networking is completed, the software program counts all photovoltaic nodes, configures multicast group numbers for STAs through CCO according to customer needs, and sends multicast messages to implement group number configuration.

[0097] In the third step, STA processes the multicast message and completes the grouping. At the same time, CCO will periodically query the status of each grouping node to maintain the normal operation of the grouping and maintain the normal and effective operation of the channel.

[0098] Step 4: CCO receives a group control message for a group according to business needs, and first checks the legitimacy of the group. Then it sends the same group control message to all nodes corresponding to the group (such as Figure 6 As shown, a downlink message is sent to all nodes corresponding to the group).

[0099] In the fifth step, the STA processes the group control message according to its own group number when the group number is the same as the target group number carried by the group control message, and then forms a discrete reporting time window according to the weights such as group size, node level, node role, and uplink message size / transmission time, and then performs random discrete delay within the discrete time window within the bound CSMA time slot, and finally responds to the CCO after the discrete delay expires.

[0100] The group multicast technology realizes the monitoring of key users such as photovoltaics by grouping the nodes in the network. The same downlink message is sent through multicast. As long as there are slave node devices sharing the communication path, the repeated sending of the same message can be reduced or avoided, reducing the bandwidth resource usage. By reducing or avoiding the repeated sending of downlink messages and reducing or avoiding the waiting for multiple rounds of execution, the overall communication delay is reduced; the uplink response message is discretely reported after a random delay, reducing or avoiding message conflicts to improve the communication success rate.

[0101] The above embodiments can achieve the following technical effects:

[0102] (1) Implement group management and control of key customers through grouping technology;

[0103] (2) Group instructions: Use multicast technology to reduce or avoid repeated transmission of the same message, thereby reducing bandwidth resource usage;

[0104] (3) Discrete reporting: The upper layer calculates the discrete window time based on the weighted calculation of group size, message size, node level, node role, etc., and then sends the message to the underlying communication link. The underlying link binds the CSMA time slot for scheduled transmission to reduce or avoid message conflicts and improve the communication success rate. The response message of the group control command is discretely reported after a random delay to reduce or avoid message conflicts and improve the communication success rate.

[0105] (4) The combination of (2) and (3) can reduce the overall communication delay, thereby reducing the occupancy of bandwidth resources.

[0106] It should be noted that the number of slave node devices in the groups presented in each embodiment of the present invention is relatively small, and its purpose is to fully illustrate the specific process, but the number in each group in the actual application scenario is large, so by reducing the repeated transmission of the same message, the bandwidth resource occupation can be greatly reduced, and the overall communication delay can be reduced by reducing the repeated transmission of downlink messages and reducing the waiting for multiple rounds of execution. In addition, the above-mentioned embodiments of the present invention are mainly explained by taking the query instruction as an example. Of course, it is also feasible for the other instructions mentioned above. The corresponding process is similar. Please refer to the description of the query process, which will not be repeated here.

[0107] To sum up, the present invention creatively completes grouping by a slave node device according to the mapping relationship in the multicast message and the identifier of the slave node device, and then, in response to the master node device sending the same group control message carrying the multicast group number, receives the group control message, and, when the multicast group number of the slave node device is the same as the target multicast group number carried by the group control message, performs corresponding control operations on the corresponding terminal devices according to the control instructions in the group control message to obtain a response message, and finally uploads the response message. It can at least solve some or all of the problems existing in the prior art. It sends the same message in a multicast manner, which can reduce the repeated sending of the same message and reduce the bandwidth resource occupation.

[0108] An embodiment of the present invention provides a multicast communication method, which is executed by a master node device, and the multicast communication method includes: sending a multicast message, wherein the multicast message includes: a mapping relationship between a device group, a multicast group number of the device group, and an identifier of a device in the device group; in response to a slave node device determining the multicast group number to which the slave node device belongs based on the mapping relationship and the identifier of the slave node device, sending a group control message carrying a target multicast group number; and in response to the slave node device determining that the multicast group number of the slave node device is the same as the target multicast group number, executing a control instruction in the group control message and uploading a response message corresponding to the group control message, and receiving the response message.

[0109] For example, if the user specifies to query the meter reading results of STA2, STA3, and STA4, CCO can assign STA2, STA3, and STA4 to a device group according to the requirement, and specify the corresponding multicast group number (for example, G1) for the device group. Figure 4 As shown; similarly, other slave node devices are assigned to other device groups as needed. CCO determines the following mapping relationship: device group 1--multicast group number G1--{STA2, STA3, STA4}, other mapping relationships are similar and are not listed here. CCO can send the determined mapping relationship to the slave node devices (such as STA1, STA2, STA3, STA4).

[0110] like Figure 4As shown, for the slave node device identified as STA2, by querying the mapping relationship device group 1--multicast group number G1--{STA2, STA3, STA4}, it can be determined that the multicast group number to which the slave node device belongs is G1; for slave node devices with other identifiers, a similar method is used to determine the multicast group number described by itself, which will not be described one by one here. In this way, the grouping process of the slave node device can be completed. When the user needs to query the node of G1, CCO can use G1 as the target group number, and carry the target group number G1 through the group control message (which includes the control instruction to query the meter reading results of STA2, STA3, and STA4), and send the group control message to STA2 and STA3 through PCO2, and send the group control message to STA4. Among them, the messages received by STA2, STA3, and STA4 are the same, and STA2 and STA3 share a communication path (some slave node devices in the same group share a communication path). CCO sends a group control message (as shown by the green arrow) through the communication path (CCO--PCO2), which is different from the existing technology. The existing method needs to send two messages (as shown by the orange arrow). In this embodiment, multicast technology is used to reduce the repeated sending of the same message and reduce the bandwidth resource occupation.

[0111] like Figure 4 As shown, STA2, STA3, and STA4 receive the same group control message sent by CCO, wherein the group control message carries a multicast group number, and CCO can forward it to STA2 and STA3 via PCO2 by sending a group control message. Specifically, when PCO2 receives the group control message, since this node does not have a multicast group number, it does not process the group control message and only forwards it. When STA2 and STA3 receive the group control message, each determines whether its own group number is the same as the multicast group number carried by the group control message to determine whether to continue processing the group control message. CCO sends an identical group control message to STA4. When STA4 receives the group control message, each determines whether its own group number is the same as the multicast group number carried by the group control message to determine whether to continue processing the group control message.

[0112] like Figure 4 As shown, when STA2, STA3 and STA4 respectively determine that the group number to which they belong is the same as the target group number, they process the group control message to obtain the control instructions, group size, and the level and role of the slave node device included in the group control message; and perform corresponding meter reading operations according to the meter reading instructions in the received group control message to obtain corresponding meter reading data.

[0113] by Figure 4For example, STA2, STA3 and STA4 upload the response messages obtained in step S204 to CCO respectively.

[0114] In one embodiment, sending the same group control message carrying the target multicast group number includes: for multiple slave node devices sharing a communication path, sending a group control message carrying the target multicast group number through the communication path, wherein the multiple slave node devices belong to the same multicast group number.

[0115] For example, if the user specifies to query the meter reading results of STA3 and STA4, CCO can assign STA3 and STA4 to a device group according to the requirement and specify the corresponding multicast group number (for example, G1) for the device group. Figure 6 As shown; similarly, other slave node devices are assigned to other device groups as needed. CCO determines the following mapping relationship: device group 1--multicast group number G1--{STA3, STA4}, other mapping relationships are similar and are not listed here. CCO can send the determined mapping relationship to the slave node devices (such as STA1, STA2, STA3, STA4, STA5, STA6).

[0116] like Figure 6 As shown, for the slave node device identified as STA2, by querying the mapping relationship device group 1--multicast group number G1--{STA3, STA4}, it can be determined that the multicast group number to which the slave node device belongs is G1; for slave node devices with other identifiers, a similar method is used to determine the multicast group number described by itself, which will not be described one by one here. In this way, the grouping process of the slave node device can be completed. When the user needs to query the node of G1, CCO can use G1 as the target group number, and carry the target group number G1 through a group control message (which includes a control instruction to query the meter reading results of STA3 and STA4), and send a group control message to all slave node devices (STA3, STA4) in the same group via the common communication path of CCO--PCO2--PCO3 (as shown by the green arrow). This is different from the prior art, and the existing method requires sending two messages (as shown by the orange arrow). In this embodiment, multicast technology is used to reduce or avoid repeated sending of the same message, thereby reducing bandwidth resource occupancy.

[0117] like Figure 6As shown, CCO can forward a group control message to STA3 and STA4 via PCO2 and PCO3 by sending it. Specifically, when PCO2 and PCO3 receive the group control message, since these two nodes do not have the multicast group number, they do not process the group control message but only forward it. When STA3 and STA4 receive the group control message, they each determine whether their own group number is the same as the multicast group number carried by the group control message to determine whether to continue processing the group control message.

[0118] like Figure 6 As shown, when STA3 and STA4 respectively determine that the group number to which they belong is the same as the target group number, they process the group control message to obtain the control instructions, group size, and the level and role of the slave node device included in the group control message; and perform corresponding meter reading operations according to the meter reading instructions in the received group control message to obtain corresponding meter reading data.

[0119] by Figure 6 For example, STA3 and STA4 upload the obtained response messages to CCO respectively.

[0120] In summary, the present invention creatively sends a multicast message through a master node device; in response to the slave node device completing the grouping according to the mapping relationship in the multicast message and the identifier of the slave node device, sends the same group control message; and in response to the slave node device determining that the multicast group number of the slave node device is the same as the target multicast group number carried by the group control message, executes the control instruction in the group control message and uploads a response message corresponding to the group control message, and receives the response message. It can at least solve some or all of the problems existing in the prior art. It sends the same message in a multicast manner, which can reduce the repeated sending of the same message and reduce the bandwidth resource occupation.

[0121] An embodiment of the present invention provides a multicast communication system, which is executed by a slave node device, and the multicast communication system includes: a receiving device, which is used to receive a multicast message, wherein the multicast message includes: a mapping relationship between a device group, a multicast group number of the device group, and an identifier of a device in the device group; a group number determination device, which is used to determine the multicast group number to which the slave node device belongs according to the mapping relationship and the identifier of the slave node device; a judgment device, which is used to receive the group control message in response to a master node device sending a group control message carrying the multicast group number, and judge whether the multicast group number of the slave node device is the same as the target multicast group number carried by the group control message; an execution device, which is used to perform a corresponding control operation on a corresponding terminal device according to a control instruction in the group control message when the multicast group number of the slave node device is the same as the target multicast group number, so as to obtain a response message, wherein the response message includes the execution result of the corresponding control operation; and an uploading device, which is used to upload the response message.

[0122] In one embodiment, the upload device includes: a window determination module, which is used to determine the reporting time window according to the group size in the group control message, the level and role of the slave node device, and the transmission time of the uplink message; an acquisition module, which is used to perform a random delay within the reporting time window within the bound CSMA time slot to obtain the reporting time; and an upload module, which is used to upload the response message when the reporting time arrives.

[0123] In one embodiment, the window determination module includes: a first determination unit for determining the window size according to the group size. , the hierarchy of the slave node device Load factor corresponding to the role , and the transmission time of the uplink message , the reporting time window T is determined by the following formula:

[0124]

[0125] in, , , are the minimum and maximum thresholds for group size, respectively; , is the minimum threshold of transmission time; , , are the minimum and maximum values ​​of the level respectively; for The weight of .

[0126] In one embodiment, the multicast communication system further includes: a message size determining device, configured to determine the transmission time of the uplink message according to the size of the uplink message and the PB block size.

[0127] In one embodiment, the message size determining device is used to determine the transmission time of the uplink message, including: when the PB block size is 72 bytes, ; When the PB block size is 136 bytes, ; When the PB block size is 264 bytes, ; and in the case of a PB block size of 520 bytes, , where M is a positive integer, the size of the uplink message is x bytes, The unit is ms.

[0128] In one embodiment, the multicast communication system further includes: a load factor determining device, configured to determine the load factor by: : In the case where the role of the slave node device is a proxy node, ; In the case where the role of the slave node device is STA, .

[0129] In one embodiment, the window determination module includes: a second determination unit, configured to: In the case of, the reporting time window is determined to be 0, where N is the group size, is the minimum threshold of the group size, and the acquisition module is used to perform random delay within the reporting time window within the bound CSMA time slot to obtain the reporting time, including: determining the random delay time as 0 to determine the current time as the reporting time.

[0130] In one embodiment, the terminal device is an electric meter, a rail meter, a collector, a water meter, or a gas meter.

[0131] In one embodiment, when the slave node device shares a communication path with other slave node devices and the slave node device and the other slave node devices belong to the same multicast group number, receiving the group control message includes: in response to the master node device sending a group control message carrying the target multicast group number through the communication path, receiving the group control message.

[0132] An embodiment of the present invention provides a multicast communication system, which is executed by a master node device, and the multicast communication system includes: a first sending device, used to send multicast messages, wherein the multicast message includes: a mapping relationship between a device group, a multicast group number of the device group, and an identifier of a device in the device group; a second sending device, used to respond to a slave node device determining the multicast group number to which the slave node device belongs based on the mapping relationship and the identifier of the slave node device, and send a group control message carrying a target multicast group number; and a receiving device, used to respond to the slave node device determining that the multicast group number of the slave node device is the same as the target multicast group number, executing the control instruction in the group control message and uploading a response message corresponding to the group control message, and receiving the response message.

[0133] In one embodiment, the second sending device is used to send the same group control message carrying the target multicast group number, including: for multiple slave node devices sharing a communication path, sending a group control message carrying the target multicast group number through the communication path, wherein the multiple slave node devices belong to the same multicast group number.

[0134] For specific details and benefits of the multicast communication system provided by the embodiment of the present invention, please refer to the above description of the multicast communication method, which will not be repeated here.

[0135] An embodiment of the present invention provides a slave node device, the slave node device comprising: an execution device, used to execute the multicast communication method.

[0136] An embodiment of the present invention provides a master node device, the master node device comprising: an execution device, used to execute the multicast communication method.

[0137] An embodiment of the present invention provides a computer-readable storage medium, wherein a computer program is stored on the computer-readable storage medium, and when the computer program is executed by a processor, the multicast communication method is implemented.

[0138] An embodiment of the present invention provides a chip, which includes: a processor; a memory for storing a computer program executed by the processor; the processor is used to read the computer program from the memory and execute the computer program to implement the multicast communication method.

[0139] An embodiment of the present invention provides a computer program product, including a computer program, which implements the multicast communication method when executed by a processor.

[0140] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present invention will not further describe various possible combinations.

[0141] Those skilled in the art can understand that all or part of the steps in the above-mentioned embodiment method can be completed by instructing the relevant hardware through a program, and the program is stored in a storage medium, including a number of instructions to enable a single-chip microcomputer, a chip or a processor to execute all or part of the steps of the method described in each embodiment of the present application. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), disk or optical disk and other media that can store program codes.

[0142] Those skilled in the art will appreciate that the embodiments of the present application may be provided as methods, systems, or computer program products. Therefore, the present application may adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Moreover, the present application may adopt the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program codes.

[0143] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0144] In addition, various embodiments of the present invention may be arbitrarily combined, and as long as they do not violate the concept of the present invention, they should also be regarded as the contents disclosed by the present invention.

Claims

1. A multicast communication method, characterized in that: Executed by a slave node device, the multicast communication method includes: Receiving a multicast message, wherein the multicast message includes: a mapping relationship between a device group, a multicast group number of the device group, and identifiers of devices in the device group; Determine the multicast group number to which the slave node device belongs according to the mapping relationship and the identifier of the slave node device; In response to the master node device sending a group control message carrying a multicast group number, receiving the group control message, and determining whether the multicast group number of the slave node device is the same as the target multicast group number carried by the group control message; When the multicast group number of the slave node device is the same as the target multicast group number, performing a corresponding control operation on the corresponding terminal device according to the control instruction in the group control message to obtain a response message, wherein the response message includes an execution result of the corresponding control operation; and Upload the response message, The uploading of the response message includes: Determine a reporting time window according to the group size in the group control message, the level and role of the slave node device, and the transmission time of the uplink message; Performing a random delay within the reporting time window within the bound CSMA time slot to obtain a reporting time; and Uploading the response message when the reporting time arrives, Determining the reporting time window includes: According to group size , the hierarchy of the slave node device Load factor corresponding to the role , and the transmission time of the uplink message , the reporting time window T is determined by the following formula: in, , , are the minimum and maximum thresholds for group size, respectively; , is the minimum threshold of transmission time; , , are the minimum and maximum values ​​of the level respectively; for The weight of .

2. The multicast communication method according to claim 1, characterized in that: The multicast communication method further includes: The transmission time of the uplink message is determined according to the size of the uplink message and the PB block size.

3. The multicast communication method according to claim 2, characterized in that: The determining the transmission time of the uplink message comprises: In the case of a PB block size of 72 bytes, ; In the case of a PB block size of 136 bytes, ; In the case of a PB block size of 264 bytes, ;as well as In the case of a PB block size of 520 bytes, , Wherein, N is a positive integer, the size of the uplink message is x bytes, and the transmission time of the uplink message is The unit is ms.

4. The multicast communication method according to claim 1, characterized in that: The multicast communication method further includes: The load factor is determined by : In the case where the role of the slave node device is a proxy node, ; When the role of the slave node device is STA, .

5. The multicast communication method according to claim 1, characterized in that: The determining of the reporting time window further includes: In the case of, the reporting time window is determined to be 0, where N is the group size, is the minimum threshold of group size, Performing a random delay within the reporting time window within the bound CSMA time slot to obtain a reporting time includes: determining the random delay time as 0 to determine the current time as the reporting time.

6. The multicast communication method according to claim 1, characterized in that: The terminal device is an electric meter, a rail meter, a collector, a water meter, or a gas meter.

7. The multicast communication method according to claim 1, characterized in that: In a case where the slave node device shares a communication path with other slave node devices and the slave node device and the other slave node devices belong to the same multicast group number, the receiving the group control message includes: In response to the master node device sending a group control message carrying a target multicast group number through the communication path, the group control message is received.

8. A multicast communication method, characterized in that: Executed by a master node device, the multicast communication method includes: Sending a multicast message, wherein the multicast message includes: a mapping relationship between a device group, a multicast group number of the device group, and identifiers of devices in the device group; In response to the slave node device determining the multicast group number to which the slave node device belongs according to the mapping relationship and the identifier of the slave node device, sending a group control message carrying the target multicast group number; and In response to the slave node device determining that the multicast group number of the slave node device is the same as the target multicast group number, executing the control instruction in the group control message and uploading a response message corresponding to the group control message, receiving the response message, Wherein, uploading the response message includes: Determine a reporting time window according to the group size in the group control message, the level and role of the slave node device, and the transmission time of the uplink message; Performing a random delay within the reporting time window within the bound CSMA time slot to obtain a reporting time; and Uploading the response message when the reporting time arrives, Determining the reporting time window includes: According to group size , the hierarchy of the slave node device Load factor corresponding to the role , and the transmission time of the uplink message , the reporting time window T is determined by the following formula: in, , , are the minimum and maximum thresholds for group size, respectively; , is the minimum threshold of transmission time; , , are the minimum and maximum values ​​of the level respectively; for The weight of .

9. The multicast communication method according to claim 8, characterized in that: The sending of the same group control message carrying the target multicast group number includes: For a plurality of slave node devices that share a communication path, a group control message carrying a target multicast group number is sent down through the communication path, wherein the multicast group number to which the plurality of slave node devices belong is the same.

10. A multicast communication system, characterized in that: Executed by a slave node device, the multicast communication system includes: A receiving device, configured to receive a multicast message, wherein the multicast message includes: a mapping relationship between a device group, a multicast group number of the device group, and identifiers of devices in the device group; A group number determining device, used to determine the multicast group number to which the slave node device belongs according to the mapping relationship and the identifier of the slave node device; A judging device, configured to receive the group control message in response to the master node device sending the same group control message carrying the multicast group number, and judge whether the multicast group number of the slave node device is the same as the target multicast group number carried by the group control message; an execution device, configured to, when the multicast group number of the slave node device is the same as the target multicast group number, execute a corresponding control operation on the corresponding terminal device according to the control instruction in the group control message to obtain a response message, wherein the response message includes an execution result of the corresponding control operation; and an uploading device, used for uploading the response message, The uploading device comprises: A window determination module, configured to determine a reporting time window according to the group size in the group control message, the level and role of the slave node device, and the transmission time of the uplink message; An acquisition module, configured to perform a random delay within the reporting time window within the bound CSMA time slot to acquire the reporting time; and an uploading module, used to upload the response message when the reporting time arrives, The window determination module comprises: The first determination unit is used to determine the size of the group , the hierarchy of the slave node device Load factor corresponding to the role , and the transmission time of the uplink message , the reporting time window T is determined by the following formula: in, , , are the minimum and maximum thresholds for group size, respectively; , is the minimum threshold of transmission time; , , are the minimum and maximum values ​​of the level respectively; for The weight of .

11. The multicast communication system according to claim 10, characterized in that: The multicast communication system further includes: The message size determining device is used to determine the transmission time of the uplink message according to the size of the uplink message and the PB block size.

12. The multicast communication system according to claim 11, characterized in that: The message size determining device is used to determine the transmission time of the uplink message, including: In the case of a PB block size of 72 bytes, ; In the case of a PB block size of 136 bytes, ; In the case of a PB block size of 264 bytes, ;as well as In the case of a PB block size of 520 bytes, , Wherein, M is a positive integer, the size of the uplink message is x bytes, The unit is ms.

13. The multicast communication system according to claim 10, characterized in that: The multicast communication system further includes: A load factor determining device is used to determine the load factor by the following method : In the case where the role of the slave node device is a proxy node, ; When the role of the slave node device is STA, .

14. The multicast communication system according to claim 10, characterized in that: The window determination module comprises: The second determining unit is used to In the case of, the reporting time window is determined to be 0, where N is the group size, is the minimum threshold of group size, The acquisition module is used to perform random delay within the reporting time window within the bound CSMA time slot to obtain the reporting time, including: determining the random delay time as 0 to determine the current time as the reporting time.

15. The multicast communication system according to claim 10, characterized in that: The terminal device is an electric meter, a rail meter, a collector, a water meter, or a gas meter.

16. The multicast communication system according to claim 10, characterized in that: In a case where the slave node device shares a communication path with other slave node devices and the slave node device and the other slave node devices belong to the same multicast group number, the receiving the group control message includes: In response to the master node device sending a group control message carrying a target multicast group number through the communication path, the group control message is received.

17. A multicast communication system, characterized in that: Executed by a master node device, the multicast communication system includes: A first sending device, configured to send a multicast message, wherein the multicast message includes: a mapping relationship between a device group, a multicast group number of the device group, and identifiers of devices in the device group; A second sending device is used for sending a same group control message carrying a target multicast group number in response to the slave node device determining the multicast group number to which the slave node device belongs according to the mapping relationship and the identifier of the slave node device; and a receiving device, configured to, in response to the slave node device determining that the multicast group number of the slave node device is the same as the target multicast group number, execute the control instruction in the group control message and upload a response message corresponding to the group control message, and receive the response message, Wherein, uploading the response message includes: Determine a reporting time window according to the group size in the group control message, the level and role of the slave node device, and the transmission time of the uplink message; Performing a random delay within the reporting time window within the bound CSMA time slot to obtain a reporting time; and Uploading the response message when the reporting time arrives, Determining the reporting time window includes: According to group size , the hierarchy of the slave node device Load factor corresponding to the role , and the transmission time of the uplink message , the reporting time window T is determined by the following formula: in, , , are the minimum and maximum thresholds for group size, respectively; , is the minimum threshold of transmission time; , , are the minimum and maximum values ​​of the level respectively; for The weight of .

18. The multicast communication system according to claim 17, characterized in that: The second sending device is used to send the same group control message carrying the target multicast group number, including: For a plurality of slave node devices that share a communication path, a group control message carrying a target multicast group number is sent down through the communication path, wherein the multicast group number to which the plurality of slave node devices belong is the same.

19. A slave node device, characterized in that: The slave node device comprises: an execution device, configured to execute the multicast communication method according to any one of claims 1-7.

20. A master node device, characterized in that: The master node device comprises: an execution device, used to execute the multicast communication method according to any one of claims 8-9.

21. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores a computer program, which, when executed by a processor, implements the multicast communication method according to any one of claims 1 to 9.

22. A chip, characterized in that: The chip includes: a processor; a memory for storing a computer program executed by the processor; the processor is used to read the computer program from the memory and execute the computer program to implement the multicast communication method described in any one of claims 1-9.

23. A computer program product, characterized in that The invention comprises a computer program, which, when executed by a processor, implements the multicast communication method according to any one of claims 1 to 9.

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