Communication method and related device

Abstract

A communication method and a related device are applied to the field of network awareness. In the application, a first node can obtain accumulated time delay information of N routing paths, and determine a target routing topology between the first node and a root node at least based on the accumulated time delay information of the N routing paths, the first node and the root node belong to the same network domain, and the path through which the message of the first node passes when being transmitted in the network comprises the first node and the root node. The shorter the time delay of message transmission between the nodes in the network domain is, the higher the stability of message transmission of the routing topology passing through the shorter time delay is, so that the target routing topology of the node transmission message in the same network domain is screened out from the obtained accumulated time delay information of the N routing paths, and the stability of the message transmission of the node transmission message in the network domain is improved. A low-delay message transmission routing path can be coordinated among the nodes. And the message of the node is transmitted through the target routing topology, so that the reliability of the end-to-end delay can be ensured.

Description

Technical Field

[0001] This application relates to the field of network perception, in particular to wireless communication technologies, and specifically to a communication method and related devices. Background Art

[0002] With the development of wireless technologies, the competitiveness of wireless technologies in terms of easy deployment, easy maintenance, and low cost has led to their increasing utilization. Wireless technologies are typically applied in wireless communication systems, which usually include multiple nodes that communicate with each other to transmit information. Multiple nodes can form a network domain through networking, and the nodes in the network domain communicate with other nodes in the network in a connectionless or connection-oriented manner. The channel for transmitting information between nodes is called a routing path. When more nodes are traversed on the routing path, the possibility of generating a longer delay is higher.

[0003] In the industry, messages are usually transmitted through a routing path based on multiple different protocols. In some solutions, a routing protocol for low-power and lossy network (RPL) based on link quality is used to route and transmit messages. This protocol stipulates that the link metric for constructing a tree-shaped topology routing is the packet loss rate (ETX). However, the packet loss rate still has certain limitations for delay, and it cannot truly reflect the delay of the routing path. In the protocols of some other solutions, messages are transmitted using a flooding method, but this is extremely likely to trigger a broadcast storm, conflict with communication, further increase the delay, and it is difficult to ensure low-delay communication for end-to-end transmission of network messages.

[0004] Therefore, within a wireless communication system, how to effectively ensure end-to-end low-delay communication and thus ensure the stability of information transmission is a hot topic being studied by those skilled in the art. Summary of the Invention

[0005] Embodiments of this application provide a communication method and related devices, which can ensure end-to-end low-delay communication and thus ensure the stability of information transmission.

[0006] In a first aspect, embodiments of this application provide a communication method. The method includes: obtaining cumulative delay information of N routing paths, and determining a target routing topology between a first node and a root node based at least on the cumulative delay information of the N routing paths, where N is an integer and N≥1. The cumulative delay information of a first routing path is used to indicate the delay for a message of the first node to reach the root node through the first routing path, and the first routing path belongs to any one of the N routing paths. The target routing topology belongs to at least one of the N routing paths, and the cumulative delay information corresponding to the target routing topology satisfies a first condition.

[0007] Among them, the first node and the root node belong to the same network domain (for example, denoted as the first network domain). Exemplarily, the first network domain includes the root node and one or more child nodes, and the first node belongs to the one or more child nodes.

[0008] Optionally, this method can be applied to the first node, for example, executed by a hardware module and / or a software module in the first node. For the sake of easy understanding, the following describes the example with the first node as the main body executing this method.

[0009] In this application, N routing paths can all support transmitting the packets of the first node to the root node, and each routing path has corresponding cumulative delay information. Among them, the cumulative delay information of a routing path from node A to node B refers to the delay experienced during packet transmission between node A and node B (or called end-to-end delay).

[0010] Since the shorter the delay of packet transmission between nodes in the network domain, the higher the stability of packet transmission through the routing topology with shorter delay. Therefore, in this application, by screening out the target routing topology for packet transmission between nodes in the same network domain from the cumulative delay information of the obtained N routing paths, a low-delay packet transmission routing path can be coordinated between nodes. Optionally, the target routing topology can be the routing path with the shortest cumulative delay. Transmitting the packets of the node through the target routing topology can ensure the reliability of the end-to-end delay.

[0011] In some solutions, both the first node and the root node support wireless communication technology, and the packet transmission between the first node and the root node is wireless transmission.

[0012] In a possible implementation manner of the first aspect, the method further includes: obtaining the hop counts of the N routing paths, and determining the target routing topology between the first node and the root node based on at least the cumulative delay information of the N routing paths, including: determining the target routing topology between the first node and the root node based on the cumulative delay information of the N routing paths and the hop counts of the N routing paths.

[0013] In the above implementation manner, since the more hop counts, the more unstable the delay, because each hop of the routing path may generate oscillations resulting in delay superposition, thus leading to routing instability. Therefore, in this application, when constructing the routing, the cumulative delay information of the routing path and the hop counts of the routing path can be comprehensively evaluated to determine the target routing topology between the first node and the root node, so as to ensure the reliability of the end-to-end delay.

[0014] In another possible implementation manner of the first aspect, when there are routing paths that meet the hop count constraint among the N routing paths, the target routing topology is the routing path that meets the hop count constraint and has the smallest hop count among the N routing paths.

[0015] In the above embodiments, when constructing the routing path, the rule of hop count constraint can be followed. In a communication environment with the same consideration of hop count, the smaller the hop count of the routing path, the more stable it is. Therefore, when there is a routing path that meets the hop count constraint among N routing paths, the routing path with the smallest hop count can be selected as the target routing topology to further ensure the reliability of the end-to-end delay.

[0016] In another possible embodiment of the first aspect, when there are multiple routing paths that meet the hop count constraint among N routing paths, the target routing topology is the routing path that meets the hop count constraint and has the shortest delay among the N routing paths.

[0017] Since the more hops there are, the more unstable the delay is, because each hop of the routing path may generate oscillations resulting in delay superposition, which in turn leads to routing instability. However, the fewer hops do not necessarily mean the delay is stable. Therefore, when constructing the routing, the cumulative delay information of the routing path, the hop count of the routing path, and the rule of following the hop count constraint can be comprehensively evaluated. The above embodiments select the path with the shortest delay under the condition of meeting the hop count constraint, which can reduce the delay of the routing path and make the delay more stable.

[0018] Taking the hop count constraint of 2 hops as an example, the routing paths for the message of node A to reach the root node include a 3-hop routing path with a delay of 63 ms, a 2-hop routing path with a delay of 68 ms, and a 2-hop routing path with a delay of 70 ms. Since the 3-hop routing path exceeds the hop count constraint, node A can select the routing path with the shortest delay (68 ms) among the two 2-hop routing paths as the target routing topology.

[0019] In another possible embodiment of the first aspect, when there is no routing path that meets the hop count constraint among N routing paths, the target routing topology is the routing path with the shortest delay among the N routing paths.

[0020] Since the more hops there are, the more unstable the delay is, because each hop of the routing path may generate oscillations resulting in delay superposition, which in turn leads to routing instability. However, the fewer hops do not necessarily mean the delay is stable. Therefore, when constructing the routing, the cumulative delay information of the routing path, the hop count of the routing path, and the rule of following the hop count constraint can be comprehensively evaluated. The above embodiments select the routing path with the shortest delay under the condition of meeting the hop count constraint, which can make the delay of the message transmitted through the routing path more stable.

[0021] Taking the hop count constraint of 2 hops as an example, the routing paths for the packets of node A to reach the root node include a 3-hop path with a latency of 63 ms, a 3-hop path with a latency of 68 ms, and a 3-hop routing path with a latency of 78 ms. Since the 3-hop path exceeds the hop count constraint and there is no routing path that satisfies the hop count constraint, in order to ensure the latency stability as much as possible, node A can select the routing path with the shortest latency (63 ms) among the three 3-hop routing paths as the target routing topology.

[0022] In another possible implementation manner of the first aspect, the hop count constraint is that the hop count satisfies the second condition, and the hop count is associated with the number of forwarding times experienced by the packets of the first node to reach the root node.

[0023] Among them, the second condition may be that the hop count of each routing path among the N routing paths is less than or less than or equal to a preset value (the preset value can be 2 hops, for example).

[0024] Optionally, the hop count of each routing path is equal to the number of forwarding times experienced by the packets of the first node to reach the root node, or the hop count of each routing path is equal to the number of forwarding times + 1.

[0025] In another possible implementation manner of the first aspect, when the hop count of the target routing topology does not satisfy the hop count constraint, a hop count warning message is sent to the root node.

[0026] In the above implementation manner, it helps the root node to troubleshoot node failures in a timely manner according to the hop count anomalies between nodes in the network domain, so as to ensure the latency stability.

[0027] In another possible implementation manner of the first aspect, the method further includes: broadcasting a first packet, where the first packet includes hop count constraint indication information of the first network domain. The hop count constraint indication information is used to represent the constraint condition that the hop count between the second node and the root node should satisfy, and the second node is other nodes in the first network domain except the first node.

[0028] In some cases, the hop count constraint indication information is carried in the packet and broadcast. Optionally, the hop count constraint indication information is carried in the packet and broadcast by the root node. The hop count constraint indication information is used to represent that the hop count of all nodes that want to join the first network domain from the root node should not exceed the hop count constraint. Through the preset hop count constraint indication information in this application, the latency stability in the same network domain can be ensured.

[0029] In another possible implementation manner of the first aspect, N≥2, and the best target routing topology is the routing path with the fewest hop counts among the N routing paths. When there are at least two routing paths with the fewest hop counts among the N paths, the target routing topology is the routing path with the shortest latency among the at least two routing paths with the fewest hop counts.

[0030] In yet another possible implementation of the first aspect, the method further includes: sending a second message to a first neighbor node of the first node, where the second message includes cumulative delay information of a target routing topology between the first node and the root node, and there is a point-to-point connection between the first neighbor node of the first node and the first node.

[0031] When nodes form a network, the nodes in the network communicate through connectionless or connection-oriented methods. In some cases, connection-oriented means that two nodes in the network have established a point-to-point connection, and at this time, messages can be sent through the point-to-point communication method. In the above implementation, the delay accumulated in each hop is carried in the message of the first node and broadcast for the neighbor nodes of the first node to select a route. For example, if the distance between node A and node B is reachable in one hop, then there is a point-to-point connection between node A and node B.

[0032] In yet another possible implementation of the first aspect, there is a point-to-point connection between the first node and the root node, and obtaining cumulative delay information of N routing paths includes: determining the delay information between the first node and the root node, and the cumulative delay information of the second routing path is the delay information between the first node and the root node, and the second routing path belongs to one of the N routing paths.

[0033] In the above implementation, a case where N = 1 and the first node is the root node is provided.

[0034] In yet another possible implementation of the first aspect, obtaining cumulative delay information of N routing paths includes: obtaining cumulative delay information of a target routing topology between a first neighbor node of the first node and the root node, where there is a point-to-point connection between the first neighbor node of the first node and the first node. Determining the delay information between the first node and the first neighbor node of the first node. According to the delay information between the first node and the first neighbor node of the first node, and the cumulative delay information of the target routing topology between the first neighbor node of the first node and the root node, determining the cumulative delay information of the second routing path, where the second routing path belongs to one of the N routing paths and the second routing path passes through the first neighbor node of the first node.

[0035] In the above implementation, a case where the first node is an ordinary node (for example, the first node is node A, and node A can be both a parent node and a child node) is provided. Exemplarily, the delay from the first neighbor node of the first node (such as node B) to the root node plus the delay between node A and node B gives the cumulative delay information for the message of the first node to reach the root node through the second routing path.

[0036] In yet another possible implementation of the first aspect, obtaining the cumulative delay information of the target routing topology between the first neighbor node of the first node and the root node includes: receiving a third message from the first neighbor node of the first node, where the third message includes the cumulative delay information of the target routing topology between the first neighbor node of the first node and the root node.

[0037] Correspondingly, when the first node is a relay node, it can receive the messages broadcast by neighbor nodes for route selection.

[0038] In yet another possible implementation of the first aspect, the method further includes: transmitting a measurement signal to the first neighbor node of the first node, where the measurement signal is used to determine the delay information between the first node and the first neighbor node of the first node.

[0039] In the above implementation, the heartbeat packet between the first node and the neighbor node of the first node carries the measurement signal, or directly uses the measurement signal as the heartbeat packet to maintain the link relationship.

[0040] In yet another possible implementation of the first aspect, the method further includes: broadcasting a fourth message, where the fourth message includes timestamp information, and the timestamp information is used by the second neighbor node of the first node to determine the target routing topology.

[0041] In the above implementation, the first node broadcasts messages to all neighbor nodes. In some cases, the timestamp information can be carried in the message, and the delay information between the first node and the second neighbor node of the first node is refreshed through the timestamp (it can also be understood that the delay is obtained by the difference between the message timestamp and the receiving moment). When the delay between the first node and the second neighbor node becomes longer, or the link between the first node and the second neighbor node is interrupted, or there is a lower delay in other neighbor nodes, then switch to other routing paths to transmit messages. By setting the timestamp, low-delay communication is further guaranteed.

[0042] Optionally, the second neighbor node can be a child node (i.e., the next-level node) of the first node in the first network domain, or a parent node (i.e., the upper-level node) or a sibling node at the same layer (i.e., the same-level node) of the first node.

[0043] In yet another possible implementation of the first aspect, the method further includes: receiving a second measurement signal from the first neighbor node. According to the second measurement signal, obtain the delay information between the first node and the first neighbor node.

[0044] Optionally, before receiving the second measurement signal from the first neighbor node, the method further includes:

[0045] Send a first measurement signal to a first neighbor node, where the first measurement signal is used to trigger the sending of a second measurement signal.

[0046] In the above embodiment, the first measurement signal is used to stimulate the first neighbor node of the first node to send a second measurement signal to the first node, and the purpose is still to enable the first node to receive the measurement signal of the first neighbor node (exemplarily, so that the first node can know the distance between the other party and itself).

[0047] In another possible embodiment of the first aspect, determining the delay information between the first node and the first neighbor node of the first node includes: determining the delay between the first node and the first neighbor node of the first node according to the delay information within a first time period.

[0048] In the above embodiment, the delay between the first node and the neighbor node of the first node is usually not an instantaneous value measured once, but may be an average value over a past period of time.

[0049] In another possible embodiment of the first aspect, the delay between the first node and the first neighbor node of the first node is the mean of the delay information within a first time period.

[0050] In another possible embodiment of the first aspect, the first time period includes at least one time slice. Determining the delay between the first node and the first neighbor node of the first node according to the delay information within the first time period includes: determining the delay between the first node and the first neighbor node of the first node according to the delay information corresponding to at least one time slice and the weight corresponding to at least one time slice.

[0051] Optionally, multiple delay information is obtained within the first time period, and each delay information corresponds to a time slice.

[0052] In the above embodiment, since the delay of the routing path usually uses the average value within a period of time, but using the average value cannot detect the change of the link quality well. For example, the link quality of a node has been very stable in the past 3 days and has accumulated a large enough average sample. When the link changes, because the change of the average value is evenly spread by the huge historical data, the routing switch is very slow. In this application, the weighted delay mean obtained by weighting the delay mean can effectively ensure the reliability of the delay.

[0053] In another possible embodiment of the first aspect, the length of each time slice in at least one time slice is the same, or the number of time slices within the first time period is multiple, and at least two time slices with different durations exist among the multiple time slices.

[0054] In yet another possible implementation of the first aspect, the number of time slices within the first time period is multiple, and the weights corresponding to the multiple time slices are different.

[0055] In yet another possible implementation of the first aspect, among at least one time slice, the time slice closer to the current time has a higher corresponding weight.

[0056] In yet another possible implementation of the first aspect, the method further includes: receiving a fifth message from the root node, where the fifth message includes one or more of the length indication information of the first time period, the time slice length indication information, and the time slice weight indication information, etc.

[0057] In yet another possible implementation of the first aspect, the method further includes: sending a third message to the root node through the target routing topology.

[0058] In the above implementation, when there is only one target routing topology, the first node reports the message through this target routing topology.

[0059] In yet another possible implementation of the first aspect, the target routing topology corresponds to M of the N routing paths, where N is an integer and N≥2, and M is an integer and M≥2. The method further includes: sending M copies of the third message to the root node through the M routing paths, where each of the M messages is sent corresponding to each of the M routing paths.

[0060] In the above implementation, when there are M target routing topologies, the first node reports M messages through the M target routing topologies. Exemplarily, in some scenarios with deterministic latency (for example, the energy household alarm data needs to be reported to the root node within 100 ms), the first node can utilize the multi-parent node feature in the routing protocol to simultaneously send multiple copies of the same message data to the primary parent node and the backup parent nodes. In this way, the messages can be transmitted on different links. Even if an accident occurs on a certain link, it can ensure that other messages are not affected, thereby enhancing the robustness and reducing the latency caused by message loss and retransmission.

[0061] Optionally, the feature of multiple transmission and selective reception is only triggered at the source node, that is, only the source node will send redundant messages to the primary parent node and the backup parent nodes, and the relay node will not trigger multiple transmission and selective reception again during forwarding to prevent a forwarding storm.

[0062] In yet another possible implementation of the first aspect, the method further includes: receiving a query message from a root node, where the query message is used to query the routing configuration information of the first node, and feeding back the routing configuration information of the first node to the root node. The routing configuration information includes one or more of the time slice length information of the first node, the time slice weight information of the first node, and the hop count constraint indication information of the first network domain, etc.

[0063] In yet another possible implementation of the first aspect, the method further includes: updating the cumulative delay information of at least one of the N routing paths, and determining the target routing topology between the first node and the root node according to the updated cumulative delay information of the N routing paths.

[0064] In the above implementation, the time interval of routing switching can be sensed by updating the cumulative delay information of the routing path, so as to ensure the stability of the target routing topology between the first node and the root node.

[0065] In yet another possible implementation of the first aspect, the delay includes one or more of the data packet delay, the data packet jitter, and the jitter delay of the neighbor nodes of the first node, etc.

[0066] In a second aspect, an embodiment of the present application provides a communication method, including: receiving a message from a first node. Updating a routing table according to the message of the first node, where the routing table is used to indicate that the next-hop node of the target routing topology passing through a second node is the first node, and the second node is a neighbor node of the root node.

[0067] Optionally, the data message from the first node can be forwarded by the second node to the root node.

[0068] In the above method, the root node can update the cumulative delay information of the message of the first node reaching the root node through different routing paths based on the message of the first node, which can ensure the reliability of the end-to-end delay.

[0069] In a third aspect, an embodiment of the present application provides a communication device, and the communication device includes a module or unit for implementing the method described in the first aspect or any possible implementation of the first aspect.

[0070] In a fourth aspect, an embodiment of the present application provides a communication device, and the communication device includes a module or unit for implementing the method described in the second aspect or any possible implementation of the second aspect.

[0071] Fifth aspect, an embodiment of the present application provides a communication device, which includes at least one processor and a communication interface; the communication interface is used for inputting and / or outputting information, and the at least one processor is used to call a computer program stored in at least one memory to implement the method described in the foregoing first aspect or any item of the first aspect.

[0072] Sixth aspect, an embodiment of the present application provides a communication device, which includes at least one processor and a communication interface; the communication interface is used for inputting and / or outputting information, and the at least one processor is used to call a computer program stored in at least one memory to implement the method described in the foregoing second aspect or any item of the second aspect.

[0073] Seventh aspect, the present application provides a chip, which includes a module or unit of the method described in the foregoing first aspect or any possible implementation manner. The module can be a software module or a hardware module.

[0074] Eighth aspect, an embodiment of the present application provides a communication system, which includes a first node and a root node, and the first node and the root node are communicatively connected. Among them, the first node is used to implement the method of any item of the first aspect, or is used to implement the method of any item of the second aspect.

[0075] Further, the communication system further includes a second node. The first node, the second node, and the root node may belong to the same network domain, and the first node, the second node, and the root node may be located on the same routing path for transmitting the message of the first node.

[0076] Ninth aspect, an embodiment of the present application provides a terminal, which includes the communication device of any item from the third aspect to the seventh aspect. Further, the terminal may be an intelligent terminal or a transportation tool such as a vehicle, a drone, or a robot.

[0077] Tenth aspect, an embodiment of the present application provides a computer-readable storage medium, which is used for storing instructions or computer programs; when the instructions or computer programs are executed, the method of any item of the first aspect or the method of any item of the second aspect is implemented.

[0078] Eleventh aspect, the present application provides a computer program product, which includes computer instructions. When the instructions run on at least one processor, the method described in any aspect or any possible implementation manner from the foregoing first aspect to the second aspect can be implemented. The computer program product may be a software installation package. In the case where the foregoing method needs to be used, the computer program product can be downloaded and executed on a computing device.

[0079] For the technical solutions provided in the third to eleventh aspects of this application, the beneficial effects can be referred to those of the technical solutions in the first to second aspects, and will not be elaborated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0080] The following will briefly introduce the drawings required for the description of the embodiments.

[0081] Figure 1 It is a schematic diagram of a network domain with a star topology structure provided by an embodiment of this application;

[0082] Figure 2 It is a schematic diagram of a network domain with a tree-like multi-hop topology structure provided by an embodiment of this application;

[0083] Figure 3 It is a schematic diagram of a wireless BMS scenario provided by an embodiment of this application;

[0084] Figure 4 It is a schematic diagram of a network domain with a mesh topology structure provided by an embodiment of this application;

[0085] Figure 5 It is a schematic diagram of a smart home scenario provided by an embodiment of this application;

[0086] Figure 6 It is a schematic diagram of a message transmission routing path provided by an embodiment of this application;

[0087] Figure 7 It is a schematic flowchart of a communication method provided by an embodiment of this application;

[0088] Figure 8 It is a schematic diagram of the format of a measurement frame provided by an embodiment of this application;

[0089] Figure 9 It is a schematic diagram of the delay of different nodes in different time slices provided by an embodiment of this application;

[0090] Figure 10 It is a schematic diagram of a target routing topology provided by an embodiment of this application;

[0091] Figure 11 It is a schematic diagram of another target routing topology provided by an embodiment of this application;

[0092] Figure 12 It is a schematic diagram of yet another target routing topology provided by an embodiment of this application;

[0093] Figure 13 It is a schematic diagram of the format of message M5 provided by an embodiment of this application;

[0094] Figure 14It is a schematic diagram of the format of a message M6 provided by an embodiment of the present application;

[0095] Figure 15 It is another schematic diagram of the format of a message M6 provided by an embodiment of the present application;

[0096] Figure 16 It is yet another schematic diagram of the format of a message M6 provided by an embodiment of the present application;

[0097] Figure 17 It is a schematic diagram of a routing table provided by an embodiment of the present application;

[0098] Figure 18 It is a schematic flowchart of another communication method provided by an embodiment of the present application;

[0099] Figure 19 It is a schematic diagram of the structure of a communication device 190 provided by an embodiment of the present application;

[0100] Figure 20 It is a schematic diagram of the structure of another communication device 200 provided by an embodiment of the present application;

[0101] Figure 21 It is a schematic diagram of the structure of yet another communication device 210 provided by an embodiment of the present application. Detailed implementation manners

[0102] In the present application, terms such as "first" and "second" are used to distinguish between identical or similar items with basically the same functions and roles. Those skilled in the art can understand that terms such as "first" and "second" do not limit the quantity and execution order, and "first" and "second" do not necessarily mean different. "And / or" describes the association relationship of associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist simultaneously, and B exists alone. The character " / " generally represents an "or" relationship between the associated objects before and after.

[0103] It should be understood that in the present application, "at least one" refers to one or more; "multiple" refers to two or more. In addition, "equal to" in the present application can be used in combination with "greater than" or "less than". In the case of "equal to" combined with "greater than", the technical solution of "greater than" is adopted; in the case of "equal to" combined with "less than", the technical solution of "less than" is adopted.

[0104] First, the relevant names or terms involved in the present application will be elaborated below for the convenience of those skilled in the art to understand.

[0105] 1. Node

[0106] A node is a device with communication capabilities, including but not limited to one or more of user equipment, network equipment, industrial equipment, etc. Among them, user equipment includes handheld terminals, wearable terminals, transportation means, in-vehicle devices, sensing devices, smart home devices, or recreational devices, etc. Handheld terminals include but are not limited to mobile phones, tablets, or laptop computers, etc. Wearable devices include but are not limited to earphones, smart bracelets, smart watches, or smart glasses, etc. Transportation means include but are not limited to vehicles, ships, aircraft, rail transit (such as subways, high-speed rails, etc.), or logistics robots (such as automated guided vehicles (AGVs), etc.). In-vehicle devices include but are not limited to domain controllers (DCs), screens, microphones, speakers, electronic keys, keyless entry, start system controllers, battery management systems (BMSs), battery packs, or battery cells, etc. Sensing devices include but are not limited to cameras, radars, lidars, light sensors, temperature sensors, or humidity sensors, etc. Smart home devices include but are not limited to projectors, smart TVs, smart refrigerators, smart home gateways, or security devices, etc. Recreational devices such as virtual reality (VR) devices, mixed reality (MR) devices, massage chairs, home theaters, game control devices, or 4D theater cockpits, etc.

[0107] Network equipment includes but is not limited to routers, switches, or base stations, etc. Industrial equipment such as industrial robots, or robotic arms, etc.

[0108] The nodes in the embodiments of this application can be applied to various scenarios such as intelligent vehicles, smart homes, smart terminals, intelligent manufacturing, or intelligent exhibition halls. In some application scenarios or some network types, devices with similar communication capabilities may not be called nodes, but for the sake of convenient description, devices with communication capabilities in the embodiments of this application are collectively referred to as nodes.

[0109] It should be understood that the communication method, communication device, communication system, or node, etc., in the embodiments of the present application, is applicable to multiple networks. For example, it is applicable to networks including wired communication networks, wireless communication networks, or networks combining wired communication and wireless communication. For example, wireless communication networks include networks connected through the following communication technologies: SparkLink (or NearLink), 802.11b / g, Bluetooth, Zigbee, radio frequency identification (RFID), ultra-wideband (UWB) technology, or wireless short-range communication systems, etc. Or, it can also be a long-distance connection technology including communication technologies based on long term evolution (LTE), 5th generation mobile networks or 5th generation wireless systems, 5th-Generation (abbreviated as 5G or 5G technology), global system for mobile communications (GSM), general packet radio service (GPRS), universal mobile telecommunications system (UMTS), and other wireless access type technologies. Again, for example, wired communication networks include networks connected through the following communication technologies: fiber connection technology, in-vehicle wired communication technology, controller area network (CAN), local interconnect network bus (LIN), CAN flexible data-rate (CAN FD), or in-vehicle Ethernet, etc., one or more of them.

[0110] 2. Network domain

[0111] The network domain usually includes multiple nodes, and the nodes can communicate with each other to transmit data. The nodes in the network domain may have different identities or different capabilities.

[0112] Taking a vehicle as an example, there can be multiple network domains in the vehicle. A network domain refers to a system composed of a group of nodes with communication relationships and the communication connection relationships (i.e., communication links) between the nodes, and is usually used to complete a specific function.

[0113] Exemplarily, a network domain may include a master node (e.g., a root node) and at least one slave node (e.g., a child node). Communication may occur between the root node and the child nodes, or between the child nodes themselves. The root node can manage the child nodes and has the function of allocating resources, responsible for allocating resources to the child nodes; the child nodes follow the scheduling of the root node and use the resources allocated by the root node to communicate with the root node and / or with other child nodes. For a network domain, any two nodes within the network domain can communicate based on communication addresses.

[0114] In some specific implementation scenarios, the master node may also be referred to as a grant (G) node, a G node, or a control node, and the slave node may also be referred to as a terminal (T) node or a T node. The communication link from the G node to the T node can be called a G link or a downlink, and the communication link from the T node to the G node can be called a T link or an uplink.

[0115] It should be understood that the identities of the management node and the terminal node are not absolute. It is just an exemplary naming for facilitating the operations of the nodes in communication under a possible connection situation. In some implementation processes, a node may be a management node or a terminal node. Even in some scenarios, a node belongs to two or more network domains simultaneously. It acts as a terminal node in some network domains and can act as a management node in other network domains. For the convenience of understanding, in some embodiments, such a node is denoted as a G(T) node.

[0116] The connections between the nodes in a network domain generally follow a certain topological structure, such as a star topology, a tree topology, or a mesh topology, etc.

[0117] Exemplarily, please refer to Figure 1 , Figure 1 which is a schematic diagram of a network domain with a star topology. Figure 1 The network domain shown in includes a G node and multiple T nodes (e.g., T1 node, T2 node,..., Tn node). Among them, the G node acts as the root node and can also act as the general management node, and the multiple T nodes act as child nodes and can also be regarded as managed nodes. Each T node is connected to the G node, and the connection relationship is represented by a dotted line. The communication between the G node and the T nodes can be two-way unicast or broadcast communication. Optionally, Figure 1 the topology shown in can be applied to vehicle-to-vehicle communication scenarios. As one Figure 1An application example of the shown communication topology. The G node can be a telematics BOX (T-BOX), and the T node can be a user terminal in the vehicle. The user terminal can be, for example, a mobile phone, a headset, a speaker, an in-vehicle device, etc. The T-BOX can also be called a remote vehicle terminal or a vehicle networking communication terminal. For example, the T-BOX can establish a communication connection with a mobile phone to achieve controls such as opening the door, locking the door, controlling the window, and turning on / off the air conditioner.

[0118] Please refer to Figure 2 , Figure 2 is a schematic diagram of a network domain with a tree-like multi-hop topology structure. Figure 2 The shown network domain includes G1 node, G2 node, G3 node, T1 node, T2 node, T3 node, and T4 node. Among them, the G1 node can be used as the root node (which can also be regarded as the general management node), and the G2 node, G3 node, T1 node, T2 node, T3 node, and T4 node are used as child nodes, which can also be regarded as managed nodes. The T1 node and T2 node are connected to the G2 node, the T3 node and T4 node are connected to the G3 node, and the G2 node and G3 node are connected to the G1 node. The G2 node can be represented as G2(T), and the G3 node can be represented as G3(T). Taking the G2 node as an example, for the communication between the G2 node and the G1 node, the G2 node can be used as the T node, and the G1 node can be used as the G node. For the communication between the G2 node and the T1 node, the G2 node can be used as the G node, and the T1 node can be used as the T node. Combining Figure 2 , the communication between the G node and the T node can be two-way unicast or broadcast. And the communication between the T nodes is forwarded through the G node, and the way of sending information during the communication process can include unicast and / or broadcast.

[0119] Optionally, Figure 2 the shown structure can be applied to energy storage management scenarios, in-vehicle communication scenarios, etc., such as wireless battery management system (BMS) scenarios, or tire pressure detection scenarios, etc. The wireless BMS scenario can be referred to Figure 3 as shown. Figure 3 In , the battery array management system (BAMS) is used as the root node, that is, the G1 node, which can also be regarded as the general management node, the battery cluster management system (BCMS) is the G(T) node, and the battery management unit (BMU) is used as the T node.

[0120] Please refer to Figure 4 , Figure 4It is a schematic diagram of a network domain with a mesh topology. Figure 4 The network domain shown includes G1 node, G2 node, G3 node, G4 node, T1 node, T2 node and T3 node. Among them, the G1 node can be used as the root node or regarded as the general management node, and the G2 node, G3 node, G4 node, T1 node, T2 node and T3 node are used as child nodes or can be regarded as managed nodes. The T1 node is connected to the G2 node, the T2 node is connected to the G4 node, the G4 node can be connected to the G2 node and the G3 node, the G2 node is connected to the G1 node, and the G3 node is connected to the G1 node. Optionally, in some cases, the T node can be connected to multiple G nodes. For example, the T1 node can also be connected to the G4 node. Among them, the G1 node can be used as the general management node, and the G2 node, G3 node and G4 node can be G(T) nodes.

[0121] Optionally, Figure 4 the structure shown can be applied to the smart home scenario. Please refer to Figure 5 , Figure 5 which is a schematic diagram of a smart home scenario, Figure 5 in which, the gateway / customer premises equipment (CPE) is used as the general management node, the air conditioner, mobile phone, refrigerator, and washing machine are nodes with dual identities, and the smart lock, water heater, speaker, printer, smart socket, and smart curtain are used as T nodes. The foregoing explanations of technical terms can be optionally used in the following embodiments.

[0122] When nodes form a network, the nodes in the network can communicate with other nodes in the network in a connectionless or connectionful manner to transmit information, and the channel for transmitting information between nodes can be called a routing path. Please refer to Figure 6 , Figure 6 which is a schematic diagram of a message transmission routing path. The network domain includes nodes N1 to N7, and there are various possible designs for their connection relationships and the identities of each node. For specific details, please refer to the foregoing related descriptions. Among them, when the node N6 communicates with the node N7, it can be achieved through the path "N6-N3-N2-N7", and the information transfer between the two passes through intermediate nodes, that is, the forwarding of nodes N2 and N3.

[0123] When there are more nodes on the routing path, the number of hops of the routing path is more, resulting in a higher possibility of unstable delay. In the industry, messages are usually transmitted through the routing path based on a variety of different protocols. In some solutions, the RPL routing based on link quality is used to transmit messages. This protocol stipulates that the link metric for constructing a tree-like topology routing is the packet loss rate (ETX), that is, the ratio of the unicast data packets sent and the acknowledgment frames received. If this value is 1, it means that all the unicast packets sent by a certain node have received the acknowledgment from the peer node, indicating that this link is very stable; the larger this value, the more unstable the link, increasing the risk of retransmission. However, this method still has certain limitations for delay. For example, there are scenarios where the packet loss rate is low but the delay is very large. In addition, the packets are of different sizes, and the packet loss rate cannot truly reflect the link delay. In other words, the most stable link can indicate the least number of retransmissions, but it does not mean the lowest delay. The size of the data packet has a great impact on the packet loss rate. A large number of small packets will reduce the expected packet loss rate value but cannot lower the delay.

[0124] In some other solutions, because the mesh protocol uses the flooding method to forward messages, it is necessary to transmit the information multiple times through multiple routing paths. However, the flooding transmission method is extremely likely to cause broadcast storms, conflict with communication, and further increase the delay. Therefore, it is difficult to guarantee the low delay of end-to-end message transmission in the network.

[0125] In view of this, the embodiments of the present application provide a communication method and related device, using the end-to-end delay as the metric for constructing the routing, that is, the metric for a certain child node to select the routing is no longer the packet loss rate but the delay. The present application can guarantee end-to-end low-delay communication, and further guarantee the stability of information transmission.

[0126] The method provided by the embodiments of the present application will be introduced below.

[0127] Please refer to Figure 7 , Figure 7 which is a schematic flowchart of a communication method provided by the embodiments of the present application. Optionally, this method can be applied to a network domain, such as one or more of the aforementioned Figures 1 to 6 network domains. As Figure 7 shown, the communication method may include step S701 and / or step S704. It should be understood that for the convenience of description, the steps are described in the order of step S701 to step S704 here, and it is not intended to limit that it must be executed in the above order. The embodiments of the present application do not limit the execution order, execution time, execution times, etc. of the above one or more steps. Steps S701 to S704 are specifically as follows:

[0128] Step S701: The first node obtains the cumulative delay information of N routing paths.

[0129] Among them, the first node is an exemplary name used to distinguish a certain node. For example, in combination with Figure 6 , the first node can be node N1, node N2 or other nodes.

[0130] The routing path is a channel for transmitting information between nodes, and the information can be transmitted from a certain node to another node along the routing path. Optionally, the information can be a message, and the message is transmitted from the first node to the root node along the routing path. Among them, the first node and the root node belong to the same network domain (for example, represented as the first network domain). Exemplarily, the first network domain includes the root node and one or more child nodes, and the first node belongs to the one or more child nodes. Optionally, there can be N routing paths for transmitting the message of the first node, where N is an integer and N≥1. For example, in combination with Figure 6 , taking the first node as node N6 and the root node as node N7 as an example, the message of node N6 reaching node N7 includes two routing paths. One routing path is node N6→node N3→node N2→node N7, and the other routing path is node N6→node N3→node N4→node N7.

[0131] The cumulative delay information is used to indicate the cumulative delay of the routing path between nodes. Exemplarily, in combination with Figure 6 , continuing to take the first node as node N6 and the root node as node N7 as an example, the routing path for the message of node N6 to reach node N7 includes a routing path with a cumulative delay of 63 ms (10 ms + 28 ms + 25 ms) (node N6→node N3→node N2→node N7) and a routing path with a cumulative delay of 68 ms (10 ms + 28 ms + 30 ms) (node N6→node N3→node N4→node N7).

[0132] Optionally, the cumulative delay information of the N routing paths can be sent by the neighbor nodes of the first node or calculated by the first node itself. Exemplarily, the neighbor node of the first node can be the parent node of the first node.

[0133] Optionally, the cumulative delay information of the first routing path is used to indicate the delay of the message of the first node reaching the root node through the first routing path, and the first routing path belongs to any one of the N routing paths. In some solutions, the cumulative delay information of the first routing path is related to the delay information between the first node and the first neighbor node of the first node, and this delay information is used to indicate the time information for transmitting the message of the first node between the first node and the first neighbor node of the first node. Optionally, the first neighbor node of the first node can be the upstream node of the first node. Exemplarily, in combination with Figure 6, Continuing with the first node being node N6 and the previous hop node of the first node being node N3 as an example, the distance between node N6 and node N3 is one hop, and the delay information between node N6 and node N3 is 10 ms. That is, the cumulative delay information of the first routing path is the delay information between node N6 and node N3, plus the sum of the delay information between other nodes on the first routing path.

[0134] In some other solutions, the cumulative delay information of the first routing path is related to the delay information between the first neighbor node of the first node and the neighbor node of the first neighbor node of the first node. This delay information is used to indicate the time information for transmitting the first node's message between the first node and the first neighbor node, and between the first node and the neighbor node of the first neighbor node. Optionally, the first neighbor node of the first node can be the previous hop node of the first node, and the neighbor node of the first neighbor node of the first node can be the previous previous hop node of the first node. Exemplarily, in combination with Figure 6 , Continuing with the first node being node N6, the previous hop node of the first node being node N3, and the previous previous hop node of the first node being node N2 as an example, the distance between node N6 and node N3 is one hop, and the distance between node N3 and node N2 is one hop. That is, the distance between node N6 and node N2 is two hops. The delay information between node N6 and node N3 is 10 ms, and the delay information between node N3 and node N2 is 28 ms. That is, the delay information between node N6 and node N2 is 38 ms. That is, the cumulative delay information of the first routing path is the sum of the delay information between node N6 and node N3, the delay information between node N3 and node N2, and the delay information between other nodes on the first routing path.

[0135] As a possible implementation, the first node transmits a measurement signal to the first neighbor node of the first node.

[0136] Among them, the measurement signal is used to determine the delay information between the first node and the first neighbor node of the first node.

[0137] Exemplarily, the measurement signal can be a second measurement signal. Optionally, the first node can receive the second measurement signal from the first neighbor node and obtain the delay information between the first node and the first neighbor node according to the second measurement signal. Further optionally, the second measurement signal can be a measurement request frame.

[0138] Exemplarily, the heartbeat packet between the first node and the first neighbor node of the first node carries a measurement frame, or directly uses the measurement frame as the heartbeat packet to maintain the link relationship. Please refer to Figure 8 , Figure 8 is a schematic diagram of the format of a measurement frame provided by an embodiment of the present application. As shown in Figure 8As shown in (a) of [], the format of the measurement request frame may include one or more of the following information:

[0139] (1) Transmission Channel Identifier (TCID), which is used to indicate the transmission channel identifier for transmitting data.

[0140] (2) Length Indication, which is used to indicate the length of the measurement request frame field.

[0141] (3) Frame Type Indication, which is used to indicate the type of the measurement request frame. Exemplarily, the measurement request frame field is defined as 0b0101.

[0142] (4) Response Mode, which is used to indicate that the current measurement request frame is in the response mode.

[0143] (5) Bytes Reserved for Future Use (RFU).

[0144] (6) Request Frame Serial Number, which is used to indicate the serial number of the measurement request frame.

[0145] (7) Frame Transmission Timestamp, which is used to indicate the timestamp information when the measurement request frame is sent.

[0146] (8) TLV indicates a data transmission mode based on byte streams. Since in an Internet of Things system, the data received by the message receiving end (such as a server) is a series of byte streams rather than character streams received by the user terminal, the TLV format can be used to encapsulate the data into bytes. Among them, the data tag "T" is used to represent the type of data, and its value range is 0 to 255. The data frame length "L" is used to represent the length of the entire data frame after encapsulation. The data value "V" is used to represent the value of the transmitted data. Different types of data values have different characteristics, and the data values can be encapsulated and filled by bytes according to the actual situation.

[0147] (9) Cyclic Redundancy Check (CRC) is a set of check codes calculated based on data, which is used to check whether the data is changed or transmitted incorrectly during the data transmission process.

[0148] Exemplarily, the measurement signal can also be the first measurement signal. Further optionally, before receiving the second measurement signal from the first neighbor node, the first node can also send the first measurement signal to the first neighbor node, and the first measurement signal is used to trigger the sending of the second measurement signal. Further optionally, the first measurement signal can be a measurement response frame.

[0149] Among them, the first measurement signal is used to stimulate the first neighbor node of the first node to send a second measurement signal to the first node, and the purpose is still to enable the first node to receive the measurement signal of the first neighbor node (exemplarily, the function of the second measurement signal can be to enable the first node to obtain the distance between the other node and the first node itself). As Figure 8 shown in (b) of

[0150] (1) TCID, which is used to indicate the transmission channel identifier of the transmitted data.

[0151] (2) Length indication, which is used to indicate the length of the measurement request frame field.

[0152] (3) Frame type indication, which is used to indicate the type of the measurement request frame. Exemplarily, the measurement request frame field is defined as 0b0110.

[0153] (4) Flag bit, which is used to indicate the operation result. Exemplarily, the flag bit has 8 bits. Among them, the "0-bit" indicates that the TLV is not recognized, the "1-bit" indicates that the length of the value defined by the length field in the TLV does not match the actual parameter value length, the "2-bit" is used to indicate the integrity of the measurement frame, and the remaining bits are reserved bits.

[0154] (5) Bytes reserved for future use (Reserved For Future Use, RFU).

[0155] (6) Request frame sequence number, which is used to indicate the sequence number of the measurement request frame.

[0156] (7) Request frame transmission timestamp, which is used to indicate the timestamp information when the measurement request frame is sent.

[0157] (8) Request frame reception timestamp, which is used to indicate the timestamp information when the measurement request frame is received.

[0158] (9) Frame transmission timestamp, which is used to indicate the timestamp information when the measurement response frame is sent.

[0159] (10)TLV indicates a data transmission mode based on byte streams. In an Internet of Things system, the data received by the message receiving end (such as a server) is in the form of byte streams rather than character streams received by user terminals. Therefore, data can be encapsulated into bytes using the TLV format. Among them, the data tag "T" is used to represent the type of data, and its value range is 0 to 255. The data frame length "L" is used to represent the length of the entire data frame after encapsulation. The data value "V" is used to represent the value of the transmitted data. Different types of data values have different characteristics, and byte-by-byte encapsulation and padding of data values can be performed according to actual situations.

[0160] (11) Cyclic redundancy check (CRC) is a set of check codes calculated based on data and is used to check whether data has been changed or transmitted incorrectly during the data transmission process.

[0161] As a possible implementation, the first node can determine the delay between the first node and the first neighbor node of the first node according to the delay information within the first time period.

[0162] Optionally, the delay between the first node and the first neighbor node of the first node is the mean value of the delay information within the first time period. In other words, the delay between the first node and its neighbor node is usually not an instantaneous value measured once, but may be an average value over a past period of time.

[0163] As another possible implementation, the first time period includes at least one time slice. The first node can determine the delay between the first node and the first neighbor node of the first node according to the delay information corresponding to at least one time slice and the weight corresponding to at least one time slice.

[0164] Optionally, multiple delay information is obtained within the first time period, and each delay information corresponds to a time slice.

[0165] In the above implementation, since the delay of the routing path usually uses the average value within a time period, but using the average value cannot detect changes in link quality well. For example, a node has had stable link quality in the past 3 days and has accumulated a large enough average sample. When the link changes, because the change in the average value is evenly spread by the huge historical data, the routing switch is very slow. In this application, the weighted delay mean value obtained by weighting the delay mean value can effectively ensure the reliability of the delay.

[0166] Optionally, the length of each time slice in at least one time slice is the same, or the number of time slices within the first time period is multiple, and at least two time slices with different durations exist among the multiple time slices.

[0167] Optionally, the number of time slices within the first time period is multiple, and the weights corresponding to the multiple time slices are different.

[0168] Optionally, for at least one time slice, the closer the time slice is to the current time, the higher the corresponding weight.

[0169] Exemplarily, according to the delay information corresponding to at least one time slice and the weight corresponding to at least one time slice, the delay between the first node and the first neighbor node of the first node is determined, and the following formula can be satisfied:

[0170] ETX = W t0 M t0 + W t1 M t1 + W t2 M t2 + W t3 M t3 + ….

[0171] Wherein, ETX is used to represent the delay between the first node and the first neighbor node of the first node, W is used to represent the time slice weight information, t is used to represent a certain time slice (which can also be called a moment), and M is used to represent the delay mean value calculated in a certain time slice (such as 5 minutes).

[0172] Optionally, the delay information corresponding to at least one time slice and the weight corresponding to at least one time slice may be carried in the message sent by the root node or pre-configured. Further optionally, the delay information corresponding to at least one time slice and the weight corresponding to at least one time slice may be associated with the service or application scenario corresponding to the node. Exemplarily, for the smart home scenario, the delay information corresponding to at least one time slice and the weight corresponding to at least one time slice can be obtained through a pre-configured table. Please refer to Figure 9 , Figure 9 is a schematic diagram of the delay of different nodes in different time slices provided by an embodiment of the present application. The t0 moment is used to represent the time slice closest to the current time slice, t1 is the second closest time slice, the t2 moment is used to represent the third closest time slice to the current time slice, the t3 moment is used to represent the fourth closest time slice to the current time slice, and the subsequent moments are analogized in turn with reference to the foregoing. Combining Figure 5, taking the first node as an air conditioner, the neighbor nodes of the first node as washing machines, and the second node as a refrigerator as an example. Suppose the average delay of the air conditioner at time t0 is 24 ms, the weight value of the air conditioner at time t0 is 1.05, the average delay of the air conditioner at time t1 is 23 ms, the weight value of the air conditioner at time t1 is 0.95, the average delay of the air conditioner at time t2 is 22 ms, the weight value of the air conditioner at time t2 is 0.80, and the average delay of the air conditioner at time t3 is 23 ms, the weight value of the air conditioner at time t3 is 0.60. Then, based on the average delay corresponding to the air conditioner at times t0 - t3 and the weight values corresponding to times t0 - t3, the delay between the air conditioner and the root node (gateway / CPE) can be determined to be 78.45 ms (24 * 1.05 + 23 * 0.95 + 22 * 0.80 + 23 * 0.60). The delays between the refrigerator, washing machine and the gateway / CPE respectively can be obtained by referring to the aforementioned calculation method and will not be elaborated here.

[0173] As a possible implementation manner, the first node receives a fifth message from the root node.

[0174] Among them, the fifth message includes one or more of the length indication information of the first time period, the time slice length indication information, the time slice weight indication information, etc. For easy distinction, the fifth message can be denoted as message M1.

[0175] Optionally, the length indication information of the first time period is used to indicate the length of the first time period (for example, the first time period is 1 hour), the time slice length indication information is used to indicate the length of each time slice within the first time period (for example, every 5 minutes within 1 hour is a time slice), and the time slice weight indication information is used to indicate the weight corresponding to each time slice within the first time period.

[0176] Step S702: The first node determines the target routing topology between the first node and the root node at least based on the cumulative delay information of N routing paths.

[0177] Among them, the target routing topology belongs to at least one of the N routing paths. Optionally, when the target routing topology belongs to one of the N routing paths, the target routing topology is the optimal routing path among the N routing paths. Further optionally, when the target routing topology belongs to at least one of the N routing paths, the target routing topology can be multiple preferred routing paths among the N routing paths. Exemplarily, combined with Figure 6, continue to take the first node as node N6 and the root node as node N7 as an example. Assume that the routing path for the message of node N6 to reach node N7 includes a routing path with an accumulated delay of 63 ms (10 ms + 28 ms + 25 ms) (node N6 → node N3 → node N2 → node N7) and a routing path with an accumulated delay of 68 ms (10 ms + 28 ms + 30 ms) (node N6 → node N3 → node N4 → node N7). The target routing topology can be the routing path with an accumulated delay of 63 ms among these two routing paths, or both of these two routing paths can be used as the target routing topology.

[0178] The accumulated delay information corresponding to the target routing topology satisfies the first condition. Exemplarily, the first condition can be that the delay of the accumulated delay information corresponding to the target routing topology is the shortest, or it can be that the delays based on the accumulated delay information corresponding to the target routing topology are sorted from short to long, and the first M delays that are close to the shortest delay are taken, where M is a positive integer and M ≥ 2. Correspondingly, the target routing topology between the first node and the root node can be the routing path with the shortest delay of the accumulated delay information among N routing paths, or the routing paths of the first M delays that are close to the shortest delay among N routing paths.

[0179] As a possible implementation, the first node sends a second message to the first neighbor node of the first node (in combination Figure 6 speaking, the first node can be N3, and the first neighbor node of the first node can be node N6). The accumulated delay information of the target routing topology between the first node and the root node can be carried in this message and broadcast, for the convenience of distinguishing, this second message is denoted as message M2. Optionally, message M2 includes the accumulated delay information of the target routing topology between the first node and the root node. Optionally, the connection between the first neighbor node of the first node and the first node is a point-to-point connection.

[0180] When nodes form a network, the nodes in the network communicate through connectionless or connection-oriented methods. In some cases, connection-oriented means that two nodes in the network establish a point-to-point connection, and at this time, messages can be sent through the point-to-point communication method. In this application, the delay accumulated for each hop can be carried in the message of the first node and broadcast for the neighbor nodes of the first node to select routes. Exemplarily, in combination Figure 6 , for example, the distance between node N6 and node N3 is reachable in one hop, then the connection between node N6 and node N3 is a point-to-point connection.

[0181] Further optionally, the accumulated delay information of the target routing topology between the first node and the root node can be carried in the RANK field of message M2 and broadcast.

[0182] In some solutions, the message M2 may carry some or all of the information in the cumulative delay information. For example, the message M2 may carry the information of the data packet delay, and / or the information of the data packet jitter, etc. Again, the message M2 may include one or more of the data packet delay, the data packet jitter, the jitter delay of the neighbor nodes of the first node, etc.

[0183] The following exemplarily introduces two implementation manners for obtaining the cumulative delay information of N routing paths when the first node is different nodes:

[0184] Implementation manner 1: The first node is the root node, and there is a point-to-point connection between the first node and the root node. The first node determines the delay information between the first node and the root node. The cumulative delay information of the second routing path is the delay information between the first node and the root node, and the second routing path belongs to one of the N routing paths. Exemplarily, combined with Figure 6 , when N = 1, there is 1 routing path in the first network domain. Assume that the first node is node N7 (coinciding with the root node), and node N7 determines that the cumulative delay information of node N7 passing through the second routing path is 0 ms.

[0185] Implementation manner 2: The first node is a child node. The first node obtains the cumulative delay information of the target routing topology between the first neighbor node of the first node and the root node. There is a point-to-point connection between the first neighbor node of the first node and the first node. The first node can determine the delay information between the first node and the first neighbor node of the first node. According to the delay information between the first node and the first neighbor node of the first node, and the cumulative delay information of the target routing topology between the first neighbor node of the first node and the root node, the cumulative delay information of the second routing path is determined, where the second routing path belongs to one of the N routing paths, and the second routing path passes through the first neighbor node of the first node.

[0186] Exemplarily, combined with Figure 6 , when N = 2, assume that the first node is node N6, the first neighbor node of the first node is node N3, the root node is node N7, and the second routing path is node N6 → node N3 → node N2 → node N7. Node N6 obtains the cumulative delay information of the target routing topology between node N3 and node N7. There is a point-to-point connection between node N3 and node N6. Node N6 obtains the cumulative delay information of the message of node N6 reaching node N7 through the routing path of node N6 → node N3 → node N2 → node N7 according to the target delay of node N3 plus the delay between node N3 and node N6.

[0187] As a possible implementation, the first node receives a third message from the first neighbor node of the first node (combined with Figure 6For example, if the first node is node N3, the first neighbor node of the first node can be node N2. The cumulative delay information of the target routing topology between the first node and the root node can be carried in the third packet and broadcast, and for the convenience of distinction, the third packet is denoted as packet M3.

[0188] As a possible implementation, the first node broadcasts a fourth packet.

[0189] Among them, the fourth packet includes timestamp information, which is used by the second neighbor node of the first node to determine the target routing topology. The timestamp information can be carried in the fourth packet and broadcast by the first node. For the convenience of distinction, this packet is denoted as packet M4.

[0190] Exemplarily, the first node can broadcast packet M4 to all neighbor nodes. The role of the timestamp is to refresh the delay information between the first node and the neighbor nodes of the first node (the delay is obtained by the difference between the packet timestamp and the receiving moment). For example, if the delay of the original parent node becomes longer, or the link of the original parent node is interrupted, or the delay of a certain neighbor node becomes shorter (that is, there is a lower delay among the neighbor nodes), then the routing path is switched. Optionally, the second neighbor node can be a child node (i.e., the next-level node) of the first node in the first network domain, or a parent node (i.e., the upper-level node) or a sibling node at the same layer (i.e., the same-level node) of the first node.

[0191] As a possible implementation manner, the first node can also obtain the hop counts of N routing paths. The hop count constraint is that the hop count satisfies the second condition, and the hop count is associated with the number of forwarding times experienced by the packet of the first node to reach the root node.

[0192] Among them, the second condition can be that the hop count of each routing path in the N routing paths is less than or less than or equal to a preset value. The preset value can be, for example, 2 hops. Exemplarily, the constraint condition that the hop count between the first node and the root node should satisfy can be to limit the maximum hop count of 2 hops between the first node and the root node. The definition of the hop count constraint is only an exemplary introduction, and there can be other possible definitions, and the present application does not limit this.

[0193] Optionally, the hop count of each routing path is equal to the number of forwarding times experienced by the packet of the first node to reach the root node, or the hop count of each routing path is equal to the number of forwarding times + 1.

[0194] Exemplarily, from the perspective of the forwarding side (for example, a one-hop node forwards a packet from a two-hop node to the root node), in this case, the number of hops of each routing path is equal to the number of forwarding times experienced by the packet of the first node to reach the root node (for example, if the number of forwarding times is 1, the number of hops is also 1). From the perspective of end-to-end reporting (for example, a two-hop node reports a packet to the root node), in this case, the number of hops of each routing path is equal to the number of forwarding times experienced by the packet of the first node to reach the root node + 1 (for example, if the number of forwarding times is 1, the number of hops is 2).

[0195] Optionally, in the case where there is a routing path that satisfies the hop count constraint among the N routing paths, the target routing topology is the routing path that satisfies the hop count constraint and has the minimum number of hops among the N routing paths.

[0196] Since the more hops there are, the more unstable the delay is, because each hop of the routing path may cause oscillations resulting in delay superposition, which in turn leads to routing instability. Therefore, in the same communication environment considering the hop count, the routing path with fewer hops is more stable. Exemplarily, assume that the hop count constraint is 3 hops. If there is a 2-hop routing path and a 3-hop routing path among the routing paths from the first node in the first network domain to the root node, and both of the above routing paths are routing paths that satisfy the hop count constraint, but when transmitting a packet through the 2-hop routing path, compared with transmitting a packet through the 3-hop routing path, the delay stability of this routing path is relatively higher. Based on this, the routing path with fewer hops (the 2-hop routing path) can be selected from the two as the target routing topology to ensure the stability of the network when transmitting packets.

[0197] As a possible implementation manner, the first node determines the target routing topology between the first node and the root node based on the cumulative delay information of the N routing paths and the number of hops of the N routing paths.

[0198] Since the more hops there are, the more unstable the delay is, because each hop of the routing path may cause oscillations resulting in delay superposition, which in turn leads to routing instability. However, fewer hops do not necessarily mean stable delay. Therefore, when constructing a route, the cumulative delay information of the routing path, the number of hops of the routing path, and the rule of following the hop count constraint can be comprehensively evaluated. Selecting the path with the shortest delay under the condition of satisfying the hop count constraint can reduce the delay of the routing path and make the delay more stable.

[0199] The above text has made an exemplary introduction to the specific contents of the cumulative delay information, the number of hops, and the target routing topology. The following lists two implementation manners for determining the target routing topology between the first node and the root node based on the cumulative delay information and the number of hops of the N routing paths:

[0200] Embodiment 1. When there are multiple routing paths that meet the hop count constraint among N routing paths, the target routing topology is the routing path that meets the hop count constraint and has the shortest delay among the N routing paths.

[0201] Exemplarily, please refer to Figure 10 , Figure 10 which is a schematic diagram of a target routing topology provided by an embodiment of the present application. Taking the first node as node N6 and the root node as node N7 as an example, assuming the hop count constraint is 3 hops, the routing paths for the message of node N6 to reach node N7 include a 3-hop routing path with a delay of 63 ms (25 ms + 28 ms + 10 ms) (node N6 → node N3 → node N2 → node N7), a 2-hop routing path with a delay of 78 ms (10 ms + 68 ms) (node N6 → node N3 → node N7), and a 3-hop routing path with a delay of 88 ms (10 ms + 30 ms + 48 ms) (node N6 → node N3 → node N4 → node N7). Since all three routing paths meet the hop count constraint, node N6 can select the routing path with the shortest delay (63 ms) among the three routing paths as the target routing topology.

[0202] Embodiment 2. When there is no routing path that meets the hop count constraint among N routing paths, the target routing topology is the routing path with the shortest delay among the N routing paths.

[0203] Exemplarily, please refer to Figure 11 , Figure 11 which is a schematic diagram of another target routing topology provided by an embodiment of the present application. Taking the first node as node N6 and the root node as node N7 as an example, assuming the hop count constraint is 2 hops, the routing paths for the message of node N6 to reach the root node include a 3-hop routing path with an accumulated delay of 63 ms (25 ms + 28 ms + 10 ms) (node N6 → node N3 → node N2 → node N7), a 3-hop routing path with an accumulated delay of 68 ms (28 ms + 30 ms + 10 ms) (node N6 → node N3 → node N8 → node N7), and a 3-hop routing path with an accumulated delay of 78 ms (43 ms + 25 ms + 10 ms) (node N6 → node N3 → node N4 → node N7). Since there is no routing path that meets the hop count constraint among the above three 3-hop routing paths, to ensure the stability of the delay as much as possible, node N6 can select the routing path with the shortest accumulated delay (63 ms) among the three 3-hop routing paths as the target routing topology.

[0204] Optionally, when N ≥ 2, the target routing topology is the routing path with the fewest hops among the N routing paths. When there are at least two routing paths with the fewest hops among the N paths, the target routing topology is the routing path with the shortest delay among the at least two routing paths with the fewest hops.

[0205] In this solution, an implementation method is provided that does not follow the hop count constraint and only considers the routing path with the fewest hops and the shortest delay among N routing paths. Exemplarily, please refer to Figure 12 , Figure 12 which is a schematic diagram of another target routing topology provided by an embodiment of the present application. Taking the first node as node N6 and the root node as node N7 as an example, the routing paths for the message of node N6 to reach node N7 include a 2-hop routing path with an accumulated delay of 70 ms (25 ms + 45 ms), a 2-hop routing path with an accumulated delay of 68 ms (48 ms + 20 ms), a 3-hop path with an accumulated delay of 63 ms (25 ms + 28 ms + 10 ms), and a 3-hop routing path with an accumulated delay of 88 ms (48 ms + 30 ms + 10 ms). Among them, the two 2-hop routing paths with accumulated delays of 70 ms and 68 ms respectively have the fewest hops among the above four routing paths. Since the above two 2-hop routing paths both have the fewest hops, based on this, the routing path with a shorter accumulated delay (i.e., the 2-hop routing path with an accumulated delay of 68 ms) can be selected as the target routing topology to ensure the stability of the network during message transmission.

[0206] Combined with the above implementation method, the present application comprehensively evaluates the hop count and accumulated delay information of the routing path, as well as the rule of following the hop count constraint, to obtain the target routing topology, which can ensure the reliability of the end-to-end delay.

[0207] Optionally, in the case where the hop count of the target routing topology does not meet the hop count constraint, the first node can send a hop count warning message to the root node.

[0208] As a possible implementation, the first node broadcasts the first message (combined with Figure 12 , the first node can be N3, and the first neighbor node of the first node can be node N6), and the hop count constraint indication information of the first network domain can be carried in this message and broadcast. The hop count constraint indication information is used to characterize the constraint conditions that the hop count between the second node and the root node should meet. In other words, the hop count constraint indication information is used to characterize that the hop count of all nodes that want to join the first network domain from the root node should not exceed the hop count constraint. The second node is other nodes in the first network domain except the first node. For the convenience of distinction, this message is denoted as message M5.

[0209] Optionally, the hop count constraint indication information of the first network domain can be carried in the option field of message M5 and broadcast. Further optionally, the hop count constraint indication information of the first network domain can be carried in the option field of the first message and broadcast by the root node. Further optionally, the hop count constraint indication information is carried in message M5 and broadcast by each layer of child nodes.

[0210] Optionally, the option field consists of TLVs. See Figure 13 , Figure 13 which is a schematic diagram of the format of a message M5 provided by an embodiment of the present application. The message M5 may include one or more of the following information:

[0211] (1) Option type, which is used to indicate the type of hop count constraint. Exemplarily, the option type field is 1 byte, and the optiontype field is defined as 0x80.

[0212] (2) Option length, which is used to indicate the size of the optiondata field. Exemplarily, the optionlength field is 1 byte, and the value of the optionlength field is 1.

[0213] (3) Option data, which is used to indicate the value of the hop count constraint. Exemplarily, the value range of the optiondata field is 1 to 255, and the length of the optiondata field is 1 byte.

[0214] As a possible implementation, the first node may receive a query message from the root node. The query message is used to query the routing configuration information of the first node, and feedback the routing configuration information of the first node to the root node. For the convenience of distinction, the query message is denoted as message M6.

[0215] Optionally, the routing configuration information includes one or more of the time slice length information of the first node, the time slice weight information of the first node, and the hop count constraint indication information of the first network domain, etc.

[0216] Optionally, the routing configuration information of the first node may be carried in the option field of the message M6 and broadcast. Further optionally, the routing configuration information of the first node may be carried in the option field of the message M6 and broadcast by the root node. Further optionally, the routing configuration information of the first node is carried in the message M6 and broadcast by each layer of child nodes.

[0217] Optionally, the option field consists of TLVs. See Figure 14 , Figure 14 which is a schematic diagram of the format of a message M6 provided by an embodiment of the present application. The routing configuration information in the message M6 may include one or more of the following information:

[0218] (1) optiontype, which is used to indicate the type of routing configuration information. Exemplarily, the option type field is 1 byte, and the optiontype field is defined as 0xC0.

[0219] (2) optionlength, which is used to indicate the size of the optiondata field. Exemplarily, the optionlength field is 1 byte, and the value of the optionlength field is 1.

[0220] (3) optiondata, which is used to indicate one or more of the time slice length information of the first node, the time slice weight information of the first node, and the hop count constraint indication information of the first network domain, etc. in the queried routing configuration information. Exemplarily, the optiondata field is 1 byte. 0x80 represents the hop count constraint indication information of the first network domain, 0x81 represents the time slice weight information of the first node, and 0x82 represents the time slice length information of the first node.

[0221] Optionally, the time slice weight information of the first node (e.g., represented as w) can be carried in the option field of message M6 and broadcast. Further optionally, the time slice weight information of the first node can be carried in the option field of message M6 and broadcast by the root node. Further optionally, the time slice weight information of the first node is carried in message M6 and broadcast by each layer of child nodes.

[0222] Optionally, the option field is composed of TLV. Please refer to Figure 15 , Figure 15 which is a schematic diagram of another format of message M6 provided by an embodiment of the present application. The time slice weight information w in message M6 may include one or more of the following information:

[0223] (1) optiontype, which is used to indicate the type of weight corresponding to the time slice. Exemplarily, the optiontype field is 1 byte, and the optiontype field is defined as 0x81.

[0224] (2) optionlength, which is used to indicate the size of the optiondata field. Exemplarily, the optionlength field is 1 byte, and the value of the optionlength field is 4.

[0225] (3) optiondata, which is used to indicate the value of the weight corresponding to the time slice. Exemplarily, the value range of the optiondata field is a floating-point decimal, and the optiondata field is 4 bytes.

[0226] Optionally, the time slice length information of the first node (e.g., represented as t) can also be carried in the option field of message M6 and broadcast. Further optionally, the time slice length information of the first node can be carried in the option field of message M6 and broadcast by the root node. Further optionally, the time slice length information of the first node is carried in message M6 and broadcast by each layer of child nodes.

[0227] Optionally, the option field consists of TLVs. Please refer to Figure 16 , Figure 16 which is another schematic diagram of the format of message M6 provided by the embodiments of the present application. The time slice length information t in the message can include one or more of the following information:

[0228] (1) optiontype, used to indicate the type of the time slice. Exemplarily, the option type field is 1 byte, and the optiontype field is defined as 0x82.

[0229] (2) optionlength, used to indicate the size of the optiondata field. Exemplarily, the unit of the time slice t is milliseconds (ms), the optionlength field is 1 byte, and the value of the optionlength field is 2.

[0230] (3) optiondata, used to indicate the value of the time slice. Exemplarily, the optiondata field is 2 bytes.

[0231] Optionally, the query message can include one or more of the first message, the second message, the third message, the fourth message, the fifth message, etc. described in the above embodiments, and the present application does not limit this.

[0232] Optionally, the first node updates the cumulative delay information of at least one of the N routing paths, and determines the target routing topology between the first node and the root node according to the updated cumulative delay information of the N routing paths.

[0233] Exemplarily, a special topology hop count can be constructed by using an attenuator, or the delay between nodes can be increased by using a jammer, and the time interval of routing switching can be sensed by updating the cumulative delay information of the routing path to ensure the stability of the target routing topology between the first node and the root node.

[0234] Further, the first node can send a message to the root node through the determined target routing topology. The following is introduced in combination with step S803:

[0235] Step S703: The first node sends the message of the first node to the root node through the target routing topology.

[0236] Accordingly, the root node receives the message of the first node from the first node. Optionally, the message of the first node received by the root node may be forwarded by the second node. Among them, the target routing topology passes through the second node, and the second node is a neighbor node of the root node.

[0237] Since the specific content of the information that the message may carry is exemplarily introduced in step S702, the following lists two possible implementation manners of sending messages:

[0238] Implementation manner 1: The first node sends a message to the root node. Exemplarily, when there is only one target routing topology, the first node sends the message of the first node to the root node through the target routing topology.

[0239] Accordingly, the root node receives a message from the first node. Optionally, the message from the first node received by the root node may be forwarded by the second node.

[0240] Implementation manner 2: The first node sends multiple messages to the root node. Exemplarily, when there are M target routing topologies, the first node sends M messages to the root node through M target routing topologies, where M is an integer and M≥2. The target routing topology corresponds to M of the N routing paths, where N is an integer and N≥2. The first node sends M messages of the first node to the root node through M routing paths, where each of the M messages is correspondingly sent through each of the M routing paths.

[0241] Accordingly, the root node receives M messages of the first node from the first node. Optionally, the messages from the first node received by the root node may be forwarded by multiple neighbor nodes of the root node.

[0242] Exemplarily, in some scenarios with deterministic delay (for example, the energy household alarm data needs to be reported to the root node within 100 ms), the first node can utilize the multi-parent node feature in the routing protocol to simultaneously send multiple identical message data to the primary parent node and the backup parent node. In this way, the messages can be transmitted on different links. Even if an accident occurs on a certain link, it can ensure that other messages are not affected, thereby enhancing the robustness and reducing the delay caused by message loss and retransmission. After receiving multiple messages, the root node can select and discard duplicate messages (i.e., perform the deduplication operation) through the packet sequence number at the application layer and retain the messages that meet its own requirements.

[0243] Optionally, the feature of multiple transmission and selective reception is only triggered at the source node, that is, only the source node will send redundant messages to the parent node and the backup parent node, and the relay node will not trigger multiple transmission and selective reception again during forwarding to prevent forwarding storms.

[0244] Optionally, the message from the first node may include one or more of the first message, the second message, the third message, the fourth message, the fifth message, etc. described in the above steps S701-S703, and the present application does not limit this. For the detailed explanations of the first message, the second message, the third message, the fourth message, the fifth message, etc., reference may be made to the embodiments described in steps S701-S703, and details are not described herein again.

[0245] Step S704: The root node updates the routing table according to the message of the first node.

[0246] Among them, the routing table is used to indicate that the next-hop node of the target routing topology passing through the first node is the second node. Exemplarily, please refer to Figure 17 , Figure 17 which is a schematic diagram of a routing table provided by an embodiment of the present application. Combining Figure 12 , in each of these initial routing tables, the routing table records the delay information between each node and its neighbor nodes. As shown in Table 1-1 in Figure 17 , taking the next-hop of the root node (such as node N7) being node N2 or node N4 as an example, the delay information from node N7 to node N2 is 25 ms, and the delay information from node N7 to node N4 is 48 ms. The information between these nodes can be respectively recorded in the routing table of the root node. After the root node summarizes the information of the above multiple nodes, an updated routing table as shown in Table 8-1 in Figure 17 can be formed. That is, the root node can update the routing information according to the delay information between each node and its neighbor nodes.

[0247] In the present application, N routing paths can all support transmitting the message of the first node to the root node, and each routing path has corresponding cumulative delay information. Among them, the cumulative delay information of a routing path from node A to node B refers to the delay experienced during the message transmission between node A and node B (or called the end-to-end delay).

[0248] Since the shorter the delay of message transmission between nodes in the network domain, the higher the stability of message transmission through the routing topology with shorter delay. Therefore, the present application screens out the target routing topology for message transmission between nodes in the same network domain through the cumulative delay information of N routing paths, and can coordinate a low-delay message transmission routing path between nodes. Optionally, the target routing topology may be the routing path with the shortest delay. Transmitting the message of the node through the target routing topology can ensure the reliability of the end-to-end delay.

[0249] The above Figure 7 describes the process of the communication method from the perspective of system interaction and provides multiple optional solutions. Next, combining Figure 18An exemplary introduction to a possible implementation is provided.

[0250] Please refer to Figure 18 , Figure 18 which is a schematic flowchart of another communication method provided by an embodiment of the present application. Optionally, this communication method can be applied to the aforementioned communication system, such as one or more of the aforementioned Figures 1 to 6 communication systems.

[0251] This communication method includes one or more steps among steps S1801 to S1804. It should be understood that for the convenience of description, the description is made in the order of steps S1801 to S1804 here, and it is not intended to limit that it must be executed in the above order. The embodiments of the present application do not limit the execution order, execution time, execution times, etc. of the above one or more steps, and other steps can be interspersed between or before and after these steps as needed. Among them, steps S1801 to S1804 are specifically as follows:

[0252] Step S1801: The first node determines the target routing topology between the first node and the root node based on the cumulative delay information of N routing paths and the number of hops of the N routing paths.

[0253] Optionally, the first node is an exemplary name used to distinguish a certain node. For example, in combination with Figure 6 , the first node can be the aforementioned node N1, node N2 or other nodes. The cumulative delay information refers to the cumulative delay indicated during the process of transmitting packets between nodes. The hop count constraint is that the hop count satisfies the second condition, and the hop count is associated with the number of forwarding times experienced by the packet of the first node to reach the root node. The target routing topology belongs to at least one of the N routing paths, and the cumulative delay information corresponding to the target routing topology satisfies the first condition. For a detailed description of the above content, please refer to Figure 6 , Figure 7 and other embodiments.

[0254] Step S1802: The first node determines whether the hop counts of the N routing paths satisfy the hop count constraint.

[0255] Exemplarily, for example, whether the hop counts of the N routing paths satisfy the hop count constraint can be to determine whether the hop count of each routing path in the N routing paths is less than or less than or equal to a preset value, and the preset value can be, for example, 2 hops).

[0256] Step S1803: In the case where there are multiple routing paths among the N routing paths that satisfy the hop count constraint, the target routing topology is the routing path that satisfies the hop count constraint and has the shortest delay among the N routing paths.

[0257] Exemplarily, in the case where multiple routing paths satisfy the hop count constraint, the first node may select the neighbor node with the shortest delay as the parent node. Furthermore, the target routing topology may be the routing path that satisfies the hop count constraint and has the shortest delay among the N routing paths.

[0258] Step S1804: In the case where there is no routing path that satisfies the hop count constraint among the N routing paths, the target routing topology is the routing path with the smallest hop count among the N routing paths.

[0259] Exemplarily, in the case where there is no routing path that satisfies the hop count constraint among the N routing paths, the first node may determine whether the first node currently has only one neighbor node. If there are multiple neighbor nodes, the neighbor node with the smallest hop count is selected as the parent node (for example, in combination with Figure 9 , taking the first node as node N3 as an example, node N3 has three neighbor nodes, namely node N2, node N4, and node N7. Node N3 may select node N7 with the smallest hop count as the parent node of node N3), and thus the target routing topology may be the routing path with the smallest hop count among the N routing paths.

[0260] Optionally, in the case where there is no routing path that satisfies the hop count constraint among the N routing paths, the first node may determine whether the first node currently has only one neighbor node. If there is only one neighbor node, the only neighbor node is selected as the parent node (for example, in combination with Figure 9 , taking the first node as node N1 as an example, node N1 has only one neighbor node, namely node N2. Therefore, node N2 can be selected as the parent node of node N1), and thus the target routing topology may be the routing path passing through this neighbor node among the N routing paths. It should be noted that the detailed explanations of the above steps S1801 - S1804 can all refer to Figure 7 the described embodiments, which will not be elaborated here.

[0261] The method of the embodiments of the present application has been elaborated in detail above. Next, the device of the embodiments of the present application is provided.

[0262] It should be understood that for the device provided in the embodiments of the present application, the division of the units therein is only a division of logical functions. In actual implementation, it may be fully or partially integrated into a physical entity, or physically separated. In addition, the units in the device may be implemented in the form of a processor calling software. For example, the device includes a processor, the processor is connected to a memory, and instructions are stored in the memory. The processor calls the instructions stored in the memory to implement any of the above methods or to implement the functions of each unit of the device, where the processor is, for example, a general - purpose processor, such as a central processing unit (CPU) or a microprocessor, and the memory is a memory inside or outside the device.

[0263] Alternatively, the units in the device can be implemented in the form of a hardware circuit. The functions of some or all of the units can be realized by designing the hardware circuit, and the hardware circuit can be understood as one or more processors. For example, in one implementation, the hardware circuit is an application-specific integrated circuit (ASIC), and the functions of some or all of the above units are realized by designing the logical relationships of the components in the circuit. Again, in another implementation, the hardware circuit can be realized by a programmable logic device (PLD). Taking the Field Programmable Gate Array (FPGA) as an example, it can include a large number of logic gate circuits, and the connection relationships between the logic gate circuits are configured through a configuration file, so as to realize the functions of some or all of the above units.

[0264] In the embodiments of the present application, each unit in the device can be one or more processors (or processing circuits) configured to implement the above methods, such as: CPU, (graphics processing unit, GPU), neural network processing unit (neural network processing Unit, NPU), tensor processing unit (tensor processing unit, TPU), deep learning processing unit (deep learning processing unit, DPU), microprocessor unit (microprocessor unit, MPU), digital signal processor (digital signal processor, DSP), ASIC, FPGA, or a combination of at least two of these processor forms.

[0265] In addition, some or all of the units in the above device can be integrated together or can be independently implemented. In one implementation, these units are integrated together and implemented in the form of a system-on-a-chip (SOC, or system-level chip). The SOC can include at least one processor for implementing any of the above methods or the functions of each unit of the device. The types of the at least one processor can be different, such as including a CPU and an FPGA, or including a CPU and an artificial intelligence processor, or including a CPU and a GPU, etc. Several possible devices are listed below.

[0266] Please refer to Figure 19 , Figure 19It is a schematic structural diagram of a communication device 190 provided by an embodiment of the present application. Optionally, the communication device 190 may be an independent device, such as a node, etc. Alternatively, the communication device 190 may also be a component in an independent device (such as a node), such as a chip or an integrated circuit, etc. The communication device 190 is used to implement the foregoing communication method, for example Figure 8 or Figure 18 the communication method shown.

[0267] In a possible design, the communication device 190 includes a communication unit 1901 and a processing unit 1902. The communication device 190 is used to implement the foregoing communication method, for example Figure 8 or Figure 18 the communication method shown. Exemplarily, the communication device is used to execute the method executed by, for example, a first node, a first neighbor node of the first node, or a second neighbor node of the first node, etc.

[0268] In a possible implementation manner, the communication unit 1901 is used to obtain the cumulative delay information of N routing paths. Among them, the cumulative delay information of the first routing path is used to indicate the delay of the message of the first node reaching the root node through the first routing path. The first routing path belongs to any one of the N routing paths. N is an integer and N≥1. The first node and the root node belong to the first network domain. The processing unit 1902 is used to determine the target routing topology between the first node and the root node at least based on the cumulative delay information of the N routing paths. The target routing topology belongs to at least one of the N routing paths, and the cumulative delay information corresponding to the target routing topology satisfies the first condition. In yet another possible implementation manner, the communication unit 1901 is further used to obtain the number of hops of the N routing paths. In terms of determining the target routing topology between the first node and the root node at least based on the cumulative delay information of the N routing paths, the processing unit 1902 is specifically used to: determine the target routing topology between the first node and the root node based on the cumulative delay information of the N routing paths and the number of hops of the N routing paths.

[0269] In yet another possible implementation manner, when there is a routing path that satisfies the hop count constraint among the N routing paths, the target routing topology is the routing path that satisfies the hop count constraint and has the smallest number of hops among the N routing paths.

[0270] In yet another possible implementation manner, when there are multiple routing paths that satisfy the hop count constraint among the N routing paths, the target routing topology is the routing path that satisfies the hop count constraint and has the shortest delay among the N routing paths. Or, when there is no routing path that satisfies the hop count constraint among the N routing paths, the target routing topology is the routing path with the shortest delay among the N routing paths.

[0271] In yet another possible implementation, the hop count constraint is that the hop count satisfies a second condition, and the hop count is associated with the number of forwarding times experienced by a message of the first node to reach the root node. Optionally, the hop count of each routing path is equal to the number of forwarding times experienced by a message of the first node to reach the root node, or the hop count of each routing path is equal to the number of forwarding times + 1.

[0272] In yet another possible implementation, the communication unit 1901 is further configured to send hop count warning information to the root node when the hop count of the target routing topology does not satisfy the hop count constraint.

[0273] In yet another possible implementation, the communication unit 1901 is further configured to broadcast a first message, where the first message includes hop count constraint indication information of a first network domain. The hop count constraint indication information is used to represent the constraint condition that the hop count between a second node and the root node should satisfy, and the second node is other nodes in the first network domain except the first node.

[0274] In yet another possible implementation, N ≥ 2, and the optimal target routing topology is the routing path with the least hop count among N routing paths. When there are at least two routing paths with the least hop count among the N paths, the target routing topology is the routing path with the shortest delay among at least two routing paths with the least hop count.

[0275] In yet another possible implementation, the communication unit 1901 is further configured to send a second message to a first neighbor node of the first node, where the second message includes cumulative delay information of the target routing topology between the first node and the root node, and there is a point-to-point connection between the first neighbor node of the first node and the first node.

[0276] In yet another possible implementation, there is a point-to-point connection between the first node and the root node. In terms of obtaining the cumulative delay information of N routing paths, the communication unit 1901 is specifically configured to: determine the delay information between the first node and the root node, and the cumulative delay information of the second routing path is the delay information between the first node and the root node, and the second routing path belongs to one of the N routing paths.

[0277] In yet another possible implementation, in terms of obtaining the cumulative delay information of N routing paths, the communication unit 1901 is specifically configured to: obtain the cumulative delay information of the target routing topology between the first neighbor node of the first node and the root node, where there is a point-to-point connection between the first neighbor node of the first node and the first node. Determine the delay information between the first node and the first neighbor node of the first node. According to the delay information between the first node and the first neighbor node of the first node, and the cumulative delay information of the target routing topology between the first neighbor node of the first node and the root node, determine the cumulative delay information of the second routing path, where the second routing path belongs to one of the N routing paths and the second routing path passes through the first neighbor node of the first node.

[0278] In yet another possible implementation, in terms of obtaining the cumulative delay information of the target routing topology between the first neighbor node of the first node and the root node, the communication unit 1901 is specifically configured to: receive a third message from the first neighbor node of the first node, where the third message includes the cumulative delay information of the target routing topology between the first neighbor node of the first node and the root node.

[0279] In yet another possible implementation, the communication unit 1901 is further configured to transmit a measurement signal to the first neighbor node of the first node, where the measurement signal is used to determine the delay information between the first node and the first neighbor node of the first node.

[0280] In yet another possible implementation, the communication unit 1901 is further configured to broadcast a fourth message, where the fourth message includes timestamp information, and the timestamp information is used by the second neighbor node of the first node to determine the target routing topology.

[0281] In yet another possible implementation, the communication unit 1901 is further configured to receive a second measurement signal from the first neighbor node. The processing unit 1902 is further configured to obtain the delay information between the first node and the first neighbor node according to the second measurement signal.

[0282] Optionally, the communication unit 1901 is further configured to send a first measurement signal to the first neighbor node, where the first measurement signal is used to trigger the sending of the second measurement signal.

[0283] In yet another possible implementation, in terms of determining the delay information between the first node and the first neighbor node of the first node, the processing unit 1902 is specifically configured to: determine the delay between the first node and the first neighbor node of the first node according to the delay information within the first time period.

[0284] In yet another possible implementation, the delay between the first node and the first neighbor node of the first node is the average value of the delay information within the first time period.

[0285] In yet another possible implementation, the first time period includes at least one time slice. In terms of determining the time delay between the first node and the first neighbor node of the first node according to the time delay information within the first time period, the processing unit 1902 is specifically configured to: determine the time delay between the first node and the first neighbor node of the first node according to the time delay information corresponding to at least one time slice and the weight corresponding to at least one time slice.

[0286] Optionally, multiple time delay information is obtained within the first time period, and each time delay information corresponds to a time slice.

[0287] In yet another possible implementation, the length of each time slice in at least one time slice is the same, or the number of time slices within the first time period is multiple, and at least two time slices with different durations exist among the multiple time slices.

[0288] In yet another possible implementation, the number of time slices within the first time period is multiple, and the weights corresponding to the multiple time slices are different.

[0289] In yet another possible implementation, among at least one time slice, the time slice closer to the current time has a higher corresponding weight.

[0290] In yet another possible implementation, the communication unit 1901 is further configured to receive a fifth message from the root node, and the fifth message includes one or more of the length indication information of the first time period, the time slice length indication information, and the time slice weight indication information, etc.

[0291] In yet another possible implementation, the communication unit 1901 is further configured to send a third message to the root node through the target routing topology.

[0292] In yet another possible implementation, the target routing topology corresponds to M of the N routing paths, where N is an integer and N≥2, and M is an integer and M≥2. The communication unit 1901 is further configured to send M copies of the third message to the root node through the M routing paths, where each of the M messages is sent corresponding to each of the M routing paths.

[0293] Optionally, the feature of multiple transmissions and selective reception is only triggered at the source node, that is, only the source node will send redundant messages to the main parent node and the standby parent node, and the relay node will not trigger multiple transmissions and selective reception again during forwarding to prevent a forwarding storm.

[0294] Please refer to Figure 20 , Figure 20It is a schematic structural diagram of another communication device 200 provided by an embodiment of the present application. Optionally, the communication device 200 may be an independent device, such as a node, etc. Alternatively, the communication device 200 may also be a component in an independent device (such as a node), such as a chip or an integrated circuit, etc. The communication device 200 is used to implement the foregoing communication method, such as Figure 7 or Figure 18 the communication method shown.

[0295] In a possible design, the communication device 200 includes a communication unit 2001 and a processing unit 2002. The communication device 200 is used to implement the foregoing communication method, such as Figure 7 or Figure 18 the communication method shown. Exemplarily, the communication device is, for example, used to execute the method executed by the root node.

[0296] In a possible implementation manner, the communication unit 2001 is used to receive a message from a first node. The processing unit 2002 is used to update the routing table according to the message of the first node. The routing table is used to indicate that the next-hop node of the target routing topology passing through a second node is the first node, and the second node is a neighbor node of the root node.

[0297] The embodiment of the present application and the above-described method embodiment are based on the same concept, and the technical effects brought by them are also the same. For the specific principle, please refer to the description of the above-described embodiment and will not be repeated here.

[0298] Please refer to Figure 21 , Figure 21 which is a schematic structural diagram of another communication device 210 provided by an embodiment of the present application. The communication device 210 may be an independent device, such as a first node or a root node, or may also be a component included in an independent device, such as a chip, a software module, or an integrated circuit, etc. The communication device 210 may include at least one processor 2101 and a communication interface 2102. Optionally, it may further include at least one memory 2103. Further optionally, it may further include a connection line 2104. Among them, the processor 2101, the communication interface 2102, and / or the memory 2103 are connected by the connection line 2104, and / or communicate with each other through the connection line 2104 to transmit control signals and / or data signals.

[0299] Among them:

[0300] The processor 2101 is a module that performs arithmetic operations and / or logical operations, and may specifically include one or more of the following modules: filter, modem, power amplifier, low noise amplifier (LNA), baseband processor, radio frequency processor, radio frequency circuit, central processing unit (CPU), application processor (AP), microcontroller unit (MCU), electronic control unit (ECU), graphics processing unit (GPU), microprocessor unit (MPU), application specific integrated circuit (ASIC), image signal processor (ISP), digital signal processor (DSP), field programmable gate array (FPGA), complex programmable logic device (CPLD), or coprocessor, etc.

[0301] The communication interface 2102 can be used to provide information input or output for at least one processor, or to receive signals sent externally and / or send signals externally.

[0302] For example, the communication interface 2102 may include an interface circuit.

[0303] For example, the communication interface 2102 may include a wired link interface such as an Ethernet cable, or may also be a wireless link (Wi-Fi, Bluetooth, general wireless transmission, vehicle short-range communication technology, and other short-range wireless communication technologies, etc.) interface.

[0304] Optionally, the communication interface 2102 may further include a radio frequency transmitter, an antenna, etc. In the case where the communication interface 2102 includes an antenna, the number of antennas may be one or multiple.

[0305] As a possible design, when the communication device 210 is an independent device, the communication interface 2102 may include a receiver and a transmitter. Among them, the receiver and the transmitter may be the same component, or different components. When the receiver and the transmitter are the same component, this component can be called a transceiver.

[0306] As another possible design, when the communication device 210 is a chip or a circuit, the communication interface 2102 may include an input interface and an output interface. The input interface and the output interface may be the same interface, or may be different interfaces respectively.

[0307] Optionally, the function of the communication interface 2102 may be implemented by a transceiver circuit or a dedicated chip for transceiver.

[0308] The memory 2103 is used to provide a storage space, and data such as an operating system and computer programs may be stored in the storage space. The memory 2103 may be one or a combination of a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM), or a compact disc read-only memory (CD-ROM), etc.

[0309] Among them, the functions and actions of each module or unit in the communication device 210 listed above are only exemplary descriptions.

[0310] Each functional unit in the communication device 210 may be used to implement the foregoing communication method, for example Figure 7 or Figure 18 the communication method shown, for example, for implementing the method executed by the first node, the first neighbor node of the first node, or the second neighbor node of the first node, etc.

[0311] Optionally, the processor 2101 may be a processor dedicated to executing the foregoing method (conveniently referred to as a dedicated processor), or may be a processor that executes the foregoing method by calling a computer program (conveniently referred to as a dedicated processor). Optionally, at least one processor may also include both a dedicated processor and a general-purpose processor.

[0312] Optionally, when the communication device 210 includes at least one memory 2103, if the processor 2101 implements the foregoing communication method by calling a computer program, the computer program may be stored in the memory 2103.

[0313] The embodiment of the present application also provides a chip, which includes a logic circuit and a communication interface. The communication interface is used to receive or send signals; the logic circuit is used to receive or send signals through the communication interface. The chip is used to implement the foregoing communication method, for example Figure 7 or Figure 18 the communication method shown.

[0314] The embodiments of this application also provide a computer-readable storage medium. Instructions are stored in the computer-readable storage medium. When the instructions run on at least one processor (or communication device), the foregoing communication method is implemented. For example Figure 7 or Figure 18 the communication method shown.

[0315] The embodiments of this application also provide a computer program product. The computer program product includes computer instructions. The computer instructions are used to implement the foregoing communication method. For example Figure 7 or Figure 18 the communication method shown.

[0316] The embodiments of this application also provide a terminal. The terminal includes the foregoing communication device 190, communication device 200, and / or communication device 210.

[0317] As a possible implementation manner, the terminal includes a root node. Further, the terminal further includes a first node and / or a second node. Further still, the terminal further includes a neighbor node of the first node and / or a second neighbor node of the first node.

[0318] Exemplarily, the terminal may include intelligent terminals or transportation means such as vehicles, robots, drones, ships, and boats. Among them, the vehicle is a vehicle in a broad sense and can be a transportation means (such as commercial vehicles, passenger vehicles, motorcycles, flying vehicles, trains, etc.), industrial vehicles (such as forklifts, trailers, tractors, etc.), engineering vehicles (such as excavators, bulldozers, cranes, etc.), agricultural equipment (such as lawn mowers, harvesters, etc.). Again, the robot may be a robot such as an automated guided vehicle (AGV), a walkable conversation robot, a service robot, etc.

[0319] It should be noted that in the embodiments of this application, words such as "exemplarily" or "for example" are used to give examples, illustrations, or explanations. Any embodiment or design solution described as "exemplarily" or "for example" in this application should not be construed as being more preferred or having more advantages than other embodiments or design solutions. Exactly speaking, using words such as "exemplarily" or "for example" aims to present relevant concepts in a specific manner.

[0320] "At least one" mentioned in the embodiments of this application refers to one or more, and "a plurality" refers to two or more. "At least one of the following" or its similar expressions refer to any combination of these items, including any combination of single items or plural items.

[0321] For example, at least one of a, b, or c may represent: a, b, c, (a and b), (a and c), (b and c), or (a, b, and c), where a, b, and c may be single or multiple. "And / or" describes the association relationship of associated objects and indicates that three relationships may exist. For example, A and / or B may represent three cases: A exists alone, A and B exist simultaneously, and B exists alone, where A and B may be singular or plural. The character " / " generally indicates that the associated objects before and after are in an "or" relationship.

[0322] In addition, unless otherwise stated, in the embodiments of the present application, ordinal numbers such as "first", "second", "M1", "M2", "M3", "M4", "M5", "S1", "S2", "S3", etc. are used to distinguish multiple objects and are not used to limit the order, timing, priority, or importance of multiple objects. For another example, the first node and the second node are only for conveniently describing fresh parameters in different embodiments and do not indicate differences in their executed operations, importance, structures, etc.

[0323] In the above embodiments, depending on the context, the term "when..." may be interpreted to mean "if...", "after...", "in response to determining...", or "in response to detecting...". The above are only optional embodiments of the present application and are not intended to limit the present application. Any modifications, equivalent replacements, improvements, etc. made within the concept and principle of the present application shall be included within the protection scope of the present application.

[0324] Those of ordinary skill in the art can understand that all or part of the steps to implement the above embodiments can be completed by hardware or by a program instructing relevant hardware. The program can be stored in a computer-readable storage medium. The storage media mentioned above can be a read-only memory, a magnetic disk, an optical disk, etc.

Claims

1. A communication method, characterized in that, Applied to a first node, the method includes: Obtaining cumulative delay information of N routing paths, where the cumulative delay information of a first routing path is used to indicate the delay for a message of the first node to reach the root node through the first routing path, the first routing path belongs to any one of the N routing paths, N is an integer and N≥1, and the first node and the root node belong to a first network domain; Determining a target routing topology between the first node and the root node based at least on the cumulative delay information of the N routing paths, the target routing topology belongs to at least one of the N routing paths, and the cumulative delay information corresponding to the target routing topology satisfies a first condition.

2. The method according to claim 1, characterized in that, The method further includes: Obtaining the hop counts of the N routing paths; The determining, based at least on the cumulative delay information of the N routing paths, the target routing topology between the first node and the root node includes: Determining the target routing topology between the first node and the root node based on the cumulative delay information of the N routing paths and the hop counts of the N routing paths.

3. The method according to claim 2, characterized in that, In a case where there are multiple routing paths satisfying the hop count constraint among the N routing paths, the target routing topology is the routing path with the shortest delay among the N routing paths that satisfies the hop count constraint, or In a case where there is no routing path satisfying the hop count constraint among the N routing paths, the target routing topology is the routing path with the shortest delay among the N routing paths.

4. The method according to claim 3, characterized in that, The hop count constraint is that the hop count satisfies a second condition, and the hop count is associated with the number of forwarding times experienced by the message of the first node to reach the root node.

5. The method according to claim 4, characterized in that, The method further includes: Sending a hop count warning message to the root node in a case where the hop count of the target routing topology does not satisfy the hop count constraint.

6. The method according to any one of claims 3 - 5, characterized in that, The method further includes: Broadcasting a first message, where the first message includes hop count constraint indication information of the first network domain, and the hop count constraint indication information is used to characterize the constraint condition that the hop count between a second node and the root node should satisfy, and the second node is other nodes in the first network domain except the first node.

7. The method according to any one of claims 1 - 6, characterized in that, The method further includes: Sending a second message to a first neighbor node of the first node, where the second message includes the cumulative delay information of the target routing topology between the first node and the root node, and the first neighbor node of the first node is point-to-point connected to the first node.

8. The method according to any one of claims 1 - 7, characterized in that, The obtaining the cumulative delay information of the N routing paths includes: Obtaining the cumulative delay information of the target routing topology between a first neighbor node of the first node and the root node, and the first neighbor node of the first node is point-to-point connected to the first node; Determining the delay information between the first node and the first neighbor node of the first node; Determine the cumulative delay information of the second routing path according to the delay information between the first node and the first neighbor node of the first node, and the cumulative delay information of the target routing topology between the first neighbor node of the first node and the root node, where the second routing path belongs to one of the N routing paths and the second routing path passes through the first neighbor node of the first node.

9. The method according to claim 8, characterized in that, The obtaining the cumulative delay information of the target routing topology between the first neighbor node of the first node and the root node includes: Receiving a third message from the first neighbor node of the first node, where the third message includes the cumulative delay information of the target routing topology between the first neighbor node of the first node and the root node.

10. The method according to claim 8 or 9, characterized in that, The method further includes: Transmitting a measurement signal with the first neighbor node of the first node, where the measurement signal is used to determine the delay information between the first node and the first neighbor node of the first node.

11. The method according to any one of claims 8 - 10, characterized in that, The determining the delay information between the first node and the first neighbor node of the first node includes: Determine the delay between the first node and the first neighbor node of the first node according to the delay information within the first time period.

12. The method according to claim 11, characterized in that, The delay between the first node and the first neighbor node of the first node is the average value of the delay information within the first time period.

13. The method according to claim 11 or 12, characterized in that The first time period includes at least one time slice. The according to the delay information within the first time period, determining the delay between the first node and the first neighbor node of the first node includes: Determine the delay between the first node and the first neighbor node of the first node according to the delay information corresponding to the at least one time slice and the weight corresponding to the at least one time slice.

14. The method according to claim 13, characterized in that The length of each time slice in the at least one time slice is the same. Alternatively, the number of time slices within the first time period is multiple, and at least two of the multiple time slices have different durations.

15. The method according to claim 13 or 14, characterized in that The number of time slices within the first time period is multiple, and the weights corresponding to the multiple time slices are different.

16. The method according to any one of claims 13 - 15, characterized in that Among the at least one time slices, the time slice closer to the current time has a higher corresponding weight.

17. The method according to any one of claims 11 - 16, characterized in that The method further includes: Receiving a fifth message from the root node, where the fifth message includes one or more of the length indication information of the first time period, the time slice length indication information, and the time slice weight indication information, etc.

18. The method according to any one of claims 1 - 17, characterized in that The method further includes: Sending the third message to the root node through the target routing topology.

19. The method according to claim 18, characterized in that The target routing topology corresponds to M of the N routing paths, where N is an integer and N≥2, M is an integer and M≥2, the method further includes: Sending M third messages to the root node through the M routing paths, where each of the M messages is sent corresponding to each of the M routing paths.

20. The method according to any one of claims 1 - 19, characterized in that The method further includes: Receiving a query message from the root node, where the query message is used to query the routing configuration information of the first node. Feedback the routing configuration information of the first node to the root node, where the routing configuration information includes one or more of the time slice length information of the first node, the time slice weight information of the first node, and the hop count constraint indication information of the first network domain, etc.

21. The method according to any one of claims 1 - 20, characterized in that The delay includes one or more of packet delay, packet jitter, and jitter delay of the neighbor nodes of the first node.

22. A communication method, characterized in that Applied to the root node, the method includes: Receive a message from the first node; Update the routing table according to the message of the first node, where the routing table is used to indicate that the next-hop node of the target routing topology passing through the second node is the first node, and the second node is a neighbor node of the root node.

23. A communication device, characterized in that The communication device includes a processor and a communication interface; When the processor calls the computer program or instruction in the memory, the method according to any one of claims 1-21 is executed.

24. A communication device, characterized in that The communication device includes a processor and a communication interface; When the processor calls the computer program or instruction in the memory, the method according to claim 22 is executed.

25. A chip, characterized in that The chip includes a processor and a communication interface; The processor is used to implement the method according to any one of claims 1-21, or implement the method according to claim 22.

26. A communication system, characterized in thatThe communication system includes a first node and a root node, The first node includes the communication device according to claim 23; The root node includes the communication device according to claim 24.

27. A terminal, characterized in that, The terminal includes the communication device according to claim 23, or includes the communication device according to claim 24, or includes the chip according to claim 25, or includes the communication system according to claim 26.

28. A computer-readable storage medium, characterized in that, The computer-readable storage medium is used to store instructions or computer programs; When the instructions or the computer program are executed, the method according to any one of claims 1-21 is implemented, or the method according to claim 22 is implemented.

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