Method for updating network topology and control node

Abstract

The embodiment of the invention provides a method for updating network topology and a control node. The method comprises the following steps: establishing a tree network topology comprising a plurality of network nodes; obtaining a signal scanning result of each network node; and updating the tree network topology based on the signal scanning result of each network node.

Description

Technical Field

[0001] The present invention relates to a technique for determining a network topology, and more particularly to a method for updating a tree - shaped network topology and a control node. Background Art

[0002] In the environment of multi - hop wireless networks (especially in industrial environments), the wireless environment is usually very complex and full of interference. Therefore, in this case, establishing a tree - shaped network topology is usually more challenging than establishing a star - shaped network topology.

[0003] In a star - shaped network topology, all nodes communicate directly with a central hub, which can simplify network management and reduce interference. In contrast, since a tree - shaped network topology involves a hierarchical structure formed by multiple interconnected nodes, establishing and maintaining such a hierarchical structure may be more complex. Moreover, interference in the network may also affect the reliability of multi - hop connections. Summary of the Invention

[0004] In view of this, the present invention provides a method for updating a network topology and a control node, which can be used to solve the above - mentioned technical problems.

[0005] An embodiment of the present invention provides a method for updating a network topology, which is executed by a control node among a plurality of network nodes, and includes: establishing a tree - shaped network topology including the plurality of network nodes; obtaining a signal scanning result of each network node, where the signal scanning result of each network node indicates a signal quality index of at least one other network node; and updating the tree - shaped network topology based on the signal scanning results of each network node.

[0006] An embodiment of the present invention provides a control node, including a storage circuit and a processor. The storage circuit stores a program code. The processor is coupled to the storage circuit and accesses the program code to execute: establishing a tree - shaped network topology including the plurality of network nodes; obtaining a signal scanning result of each network node, where the signal scanning result of each network node indicates a signal quality index of at least one other network node; and updating the tree - shaped network topology based on the signal scanning results of each network node. Brief Description of the Drawings

[0007] The accompanying drawings are included to provide a further understanding of the present invention, and are incorporated into and constitute a part of this specification. The drawings illustrate embodiments of the present invention and, together with the description, are used to explain the principles of the present invention.

[0008] Figure 1 It is a schematic diagram of a control node illustrated according to an embodiment of the present invention.

[0009] Figure 2 It is a flowchart of a method for updating a network topology illustrated according to an embodiment of the present invention.

[0010] Figure 3 It is a schematic diagram of establishing an initial tree - shaped network topology illustrated according to an embodiment of the present invention.

[0011] Figure 4 It is a flowchart of updating the tree - shaped network topology illustrated according to the first embodiment.

[0012] Figures 5A to 5B It is an application scenario diagram illustrated according to the first embodiment of the present invention.

[0013] Figure 6 It is a flowchart of updating the tree - shaped network topology illustrated according to the second and third embodiments.

[0014] Figures 7A to 7C It is an application scenario diagram illustrated according to the second embodiment of the present invention.

[0015] Figures 8A to 8C It is an application scenario diagram illustrated according to the third embodiment of the present invention.

[0016] Figures 9A to 9E It is a schematic diagram of inappropriate connection methods of each remote node illustrated according to an embodiment of the present invention.

[0017] Figure 10 It is a method of maintaining the tree - shaped network topology illustrated according to the fourth embodiment of the present invention.

[0018] Figures 11A to 11D It is an application scenario diagram illustrated according to the fourth embodiment of the present invention. Detailed implementation manners

[0019] Now, reference will be made in detail to the exemplary embodiments of the present invention. Examples of the exemplary embodiments are illustrated in the accompanying drawings. Whenever possible, the same component symbols are used in the drawings and the description to represent the same or similar parts.

[0020] Please refer to Figure 1 , which is a schematic diagram of a control node illustrated according to an embodiment of the present invention. In different embodiments, the control node 100 can be implemented as various intelligent devices and / or computer devices, but is not limited thereto. In some embodiments, the control node 100 can belong to a multi - hop wireless network system including multiple network nodes.

[0021] In one embodiment, the control node 100 is, for example, a multi - point relay (MPR) among the multiple network nodes and can be used to manage one or more member nodes in the multi - hop wireless network system, where each member node is, for example, other network nodes other than the control node 100.

[0022] In some embodiments, the one or more member nodes are, for example, mesh access points (MAPs) in a multi-hop wireless network system. Additionally, in one embodiment, each member node is connected to an external network only through the control node 100, where the external network includes, for example, a control center such as a Supervisory Control and Data Acquisition (SCADA) system, but is not limited thereto.

[0023] In different embodiments, the control node 100 may be predefined or determined by the plurality of network nodes through a specific competition mechanism, but is not limited thereto.

[0024] In Figure 1 , the control node 100 includes a storage circuit 102 and a processor 104.

[0025] The storage circuit 102 is, for example, any type of fixed or removable random access memory (RAM), read-only memory (ROM), flash memory, hard disk, or other similar devices or a combination of these devices, and can be used to record a plurality of program codes or modules.

[0026] The processor 104 is coupled to the storage circuit 102 and can be a general-purpose processor, a special-purpose processor, a conventional processor, a digital signal processor, multiple microprocessors, one or more microprocessors combined with a digital signal processor core, a controller, a microcontroller, an application specific integrated circuit (ASIC), a field programmable gate array circuit (FPGA), any other type of integrated circuit, a state machine, a processor based on an advanced RISC machine (ARM), and the like. In the embodiments of the present invention, each network node may have the same or similar structure.

[0027] In the embodiments of the present invention, the processor 104 can access the modules and program codes recorded in the storage circuit 102 to implement the method for updating the network topology proposed by the present invention, the details of which are described in detail below.

[0028] Please refer to Figure 2 , which is a flowchart of the method for updating the network topology illustrated according to an embodiment of the present invention. The method of this embodiment can be executed by Figure 1 the control node 100, and the following is in coordination withFigure 1 Component description as shown Figure 2 Details of each step

[0029] In step S210, the processor 104 establishes a tree network topology including the multiple network nodes. In different embodiments, the processor 104 and other member nodes can establish an initial tree network topology based on any existing algorithm for establishing a network topology.

[0030] Please refer to Figure 3 , which is a schematic diagram of establishing an initial tree network topology illustrated according to an embodiment of the present invention.

[0031] In Figure 3 , it is assumed that the multi-hop wireless network system 300 includes network nodes such as a control node 100 (e.g., an MPR) and member nodes 11, 12, 13, 21, 22, 23, 31, 32, 33, 34 (e.g., a MAP), etc., and the control node 100 and the shown member nodes can establish an initial tree network topology 310 based on a certain existing algorithm.

[0032] It can be seen from Figure 3 that each member node can be directly connected to the control node 100 in the tree network topology 310, or indirectly connected to the control node 100 through other member nodes. For example, member nodes 11, 13, 21, 22, 31 can be directly connected to the control node 100.

[0033] In addition, member nodes 12, 23, 32, 33, 34 can be indirectly connected to the control node 100 through other member nodes. For example, member node 12 can be indirectly connected to the control node 100 through member node 11. In this case, member node 11 can be regarded as a relay node of member node 12. Or, member node 11 can also be called the parent node of member node 12, and member node 12 can be called the child node of member node 11.

[0034] In an embodiment, member node 11 can be connected to the wireless terminal interface of member node 12 through its own access point interface to operate as a relay node and / or parent node of member node 12. From another perspective, member node 12 can operate as a wireless terminal served by member node 11, and member node 11 can provide an access point function and operate as an access point serving member node 12. That is, the child node can operate as a wireless terminal served by the parent node, and the parent node can operate as an access point serving the child node.

[0035] As another example, member node 23 can be indirectly connected to control node 100 through member node 22. In this case, member node 22 can be regarded as a relay node of member node 23. Alternatively, member node 22 can also be referred to as the parent node of member node 23, and member node 23 can be referred to as the child node of member node 22.

[0036] In one embodiment, member node 22 can be connected to the wireless terminal interface of member node 23 through its own access point interface to operate as a relay node and / or parent node of member node 23. From another perspective, member node 23 can operate as a wireless terminal served by member node 22, and member node 22 can provide an access point function and operate as an access point serving member node 23.

[0037] In addition, a member node operating as a child node can also operate as a relay node (i.e., parent node) of other member nodes at the same time. For example, in addition to operating as a child node of member node 31, member node 32 can also operate as a relay node (i.e., parent node) of member node 34 at the same time.

[0038] However, Figure 3 Some of the member nodes in may use a connection method with lower transmission quality and / or unreliability due to the content of the algorithms used. For example, although member nodes 13 and 22 are far from control node 100, they are configured to be directly connected to control node 100 in the tree network topology 310 established based on existing algorithms. In this case, it may cause member nodes 13 and 22 to fail to achieve better transmission quality and / or reliability.

[0039] Based on this, control node 100 can update the tree network topology 310 through subsequent steps S220 and S230 to attempt to adjust the connection methods of member nodes 13, 22 and / or other member nodes with control node 100, thereby improving the transmission quality and / or reliability.

[0040] In step S220, processor 104 obtains the signal scanning results of each network node.

[0041] In one embodiment, each network node can send a broadcast signal, and this broadcast signal can include the identity information of the network node itself. For example, control node 100 can send a broadcast signal including the identity information of control node 100, and Figure 3 each member node in can correspondingly detect the signal quality index of the broadcast signal from control node 100 and establish a corresponding signal scanning result based on it. Also for example, member node 11 can send a broadcast signal including the identity information of member node 11, and Figure 3The control node 100 and other member nodes therein can correspondingly detect the signal quality indicators of the broadcast signals from the member node 11, and establish corresponding signal scanning results accordingly.

[0042] Based on this, in an embodiment of the present invention, the signal scanning results of each network node can indicate the signal quality indicators of other network nodes. For example, in the signal scanning result established by the control node 100, it may include, for example, the individual signal quality indicators of one or more of the member nodes 11, 12, 13, 21, 22, 23, 31, 32, 33, 34. For another example, in the signal scanning result established by the member node 11, it may include, for example, the individual signal quality indicators of one or more of the control node 100, the member nodes 12, 13, 21, 22, 23, 31, 32, 33, 34. In one embodiment, the content of the signal scanning results established by other member nodes can be inferred according to the above teachings, and will not be elaborated herein.

[0043] In one embodiment, the signal scanning results established by each network node can be implemented in the form of a list, which may record other network nodes and their corresponding signal quality indicators. In different embodiments, the signal quality indicators may include, for example, signal strength, signal strength index, signal range index, etc. In addition, the signal quality indicators of each network node may also include, for example, the GPS location information corresponding to each network node, satellite signal strength, etc., but are not limited thereto.

[0044] In one embodiment, the control node 100 directly or indirectly obtains the signal scanning results of each member node through the tree network topology 310. For example, since Figure 3 the member nodes 11, 13, 21, 22, 31 in therein are directly connected to the control node 100, the control node 100 can directly obtain the corresponding signal scanning results from the member nodes 11, 13, 21, 22, 31.

[0045] In addition, since Figure 3 the member nodes 12, 23, 32, 33, 34 in therein are indirectly connected to the control node 100 through other member nodes, the control node 100 can indirectly obtain the signal scanning results of each member node 12, 23, 32, 33, 34. For example, the control node 100 can obtain the signal scanning result of the member node 12 from the member node 12 through the member node 11. For another example, the control node 100 can obtain the signal scanning result of the member node 23 from the member node 23 through the member node 22, but is not limited thereto.

[0046] After that, in step S230, the processor 104 updates the tree network topology 310 based on the signal scanning results of each network node.

[0047] In an embodiment of the present invention, step S230 may include one or more of the following first, second, and third embodiments, which will be further described below.

[0048] Please refer to Figure 4 , which is a flowchart of updating a tree network topology illustrated according to the first embodiment. Additionally, to make the first embodiment easier to understand, the following will be further supplemented with Figures 5A to 5B for illustration, where Figures 5A to 5B is an application scenario diagram illustrated according to the first embodiment of the present invention.

[0049] In step S410, in response to determining that the signal scanning result of control node 100 indicates the presence of a first member node and a second member node among the member nodes, processor 104 updates the tree network topology 310 by controlling each first member node to be directly connected to control node 100.

[0050] In one embodiment, the signal quality index of each first member node in the signal scanning result of control node 100 satisfies a first preset condition, and the signal quality index of each second member node in the signal scanning result of control node 100 does not satisfy the first preset condition.

[0051] In one embodiment, if the signal strength of a certain member node in the signal scanning result of control node 100 is not lower than a preset strength threshold (e.g., -70 dBm), then processor 104 may determine that the signal quality index of this member node in the signal scanning result of control node 100 satisfies the first preset condition; otherwise, it may be determined that the signal quality index of this member node in the signal scanning result of control node 100 does not satisfy the first preset condition, but it is not limited thereto.

[0052] In Figure 5A , the signal transmission range corresponding to the preset strength threshold for each network node can be illustrated as a corresponding solid / dashed circular range. For example, for each of the member nodes 11, 21, 31 located within the signal transmission range 100a of control node 100 (which is, for example, a circular range centered on control node 100), the signal strength of the broadcast signal from control node 100 detected by each of the member nodes 11, 21, 31 is not lower than the preset strength threshold. For another example, for member node 12 and control node 100 located within the signal transmission range 11a of member node 11 (which is, for example, a circular range centered on member node 11), the signal strength of the broadcast signal from member node 11 detected by member node 12 and control node 100 is not lower than the preset strength threshold.

[0053] In addition, for another node B outside the signal transmission range of a certain node A, it does not mean that this another node B cannot receive the signal from node A, but only that the signal strength of the signal received by node B from node A may be lower than a preset strength threshold. For example, although Figure 5A the member node 33 in

[0054] is not within the signal transmission range 100a of the control node 100, this does not necessarily mean that the member node 33 cannot receive the signal from the control node 100, but may only mean that the signal strength of the signal received by the member node 33 from the control node 100 is lower than the preset strength threshold, but it is not limited to this. Figure 5A In

[0055] this scenario, since the control node 100 is within the signal transmission ranges corresponding to the member nodes 11, 21, 31, the signal strengths of the member nodes 11, 21, 31 in the signal scanning result of the control node 100 should not be lower than the preset strength threshold. In this case, the processor 104 can determine that the signal quality indicators of the member nodes 11, 21, 31 in the signal scanning result of the control node 100 meet the first preset condition, and then determine the member nodes 11, 21, 31 as the above-mentioned first member nodes. Figure 5B As shown in

[0056] Accordingly, the processor 104 can update the tree network topology 310 by controlling each of the member nodes 11, 21, 31 to be directly connected to the control node 100, as

[0057] shown. Figure 5B In addition, since the control node 100 is not within the signal transmission ranges corresponding to the member nodes 12, 13, 22, 23, 32, 33, 34, the signal strengths of the member nodes 12, 13, 22, 23, 32, 33, 34 in the signal scanning result of the control node 100 should be lower than the preset strength threshold. In this case, the processor 104 can determine that the signal quality indicators of the member nodes 12, 13, 22, 23, 32, 33, 34 in the signal scanning result of the control node 100 do not meet the first preset condition, and then determine the member nodes 12, 13, 22, 23, 32, 33, 34 as the above-mentioned second member nodes.

[0058] In an embodiment of the present invention, an updated node can be understood as a member node that has been connected to the control node 100 in a better manner (e.g., higher transmission quality and / or reliability), while an unupdated node can be understood as a member node that may not have been connected to the control node 100 in a better manner, but this is not limited thereto.

[0059] Based on the content of the first embodiment, the processor 104 can determine which member nodes are more suitable for directly connecting to the control node 100 and accordingly control these member nodes to directly connect to the control node 100. After that, the processor 104 can then execute the means of the second and third embodiments.

[0060] Please refer to Figure 6 , which is a flowchart showing the updated tree network topology illustrated according to the second and third embodiments. In Figure 6 , the processor 104 can implement the content of the second embodiment by executing steps S610 to S650, and implement the content of the third embodiment by executing steps S660 to S680.

[0061] In step S610, in the i-th stage, the processor 104 obtains a first reference node that was marked as belonging to an updated node in the (i - 1)-th stage, where i is an index value greater than or equal to 1. In step S620, the processor 104 determines whether the signal scanning result of each first reference node indicates the existence of a third member node among the unupdated nodes, where the signal quality index of each such third member node in the signal scanning result of the corresponding first reference node satisfies the first preset condition.

[0062] In step S630, the processor 104 updates the tree network topology by controlling each third member node to directly connect to the corresponding first reference node.

[0063] In step S640, the processor 104 marks the third member nodes as belonging to the updated nodes, and in step S650, increments i by 1 and then returns to step S620.

[0064] For ease of understanding, the details of the second embodiment will be supplemented with Figures 7A to 7C illustrations below, where Figures 7A to 7C is an application scenario diagram illustrated according to the second embodiment of the present invention.

[0065] In Figure 7A the scenario, it is assumed that the processor 104 has just completed the means of the first embodiment and determined the tree network topology 310 as shown in Figure 5B . In this case, the processor 104 can then execute the means of the second embodiment.

[0066] In the second embodiment at the start, the initial value of i can be set to 1. In this case, the processor 104 can determine the first member node in the first embodiment as the first reference node in step S610. That is, when i is 1, the processor 104 can Figure 7A the member nodes 11, 21, 31 in

[0067] be determined as the first reference node in step S610. After that, the processor 104 can determine in step S620 whether the signal scanning results of the member nodes 11, 21, 31 indicate the existence of a third member node among the unupdated nodes (for example, the member nodes 12, 13, 22, 23, 32, 33, 34).

[0068] In Figure 7A , since the member node 12 is within the signal transmission range corresponding to the member node 11, the signal strength of the member node 12 in the signal scanning result of the member node 11 should not be lower than the preset strength threshold. In this case, the processor 104 can determine that the signal quality index of the member node 12 in the signal scanning result of the member node 11 meets the first preset condition, and then determine the member node 12 as the third member node corresponding to the member node 11.

[0069] In addition, since the member node 22 is within the signal transmission range corresponding to the member node 21, the signal strength of the member node 22 in the signal scanning result of the member node 21 should not be lower than the preset strength threshold. In this case, the processor 104 can determine that the signal quality index of the member node 22 in the signal scanning result of the member node 21 meets the first preset condition, and then determine the member node 22 as the third member node corresponding to the member node 21.

[0070] Based on this, when i is 1, the determination result of the processor 104 in step S620 should be "yes", and it can continue to execute step S630 to update the tree network topology 310 by controlling each third member node to be directly connected to the corresponding first reference node.

[0071] In Figure 7A this scenario, the processor 104 can control the member node 12 to be directly connected to the corresponding first reference node (i.e., the member node 11), and control the member node 22 to be directly connected to the corresponding first reference node (i.e., the member node 21) to update the tree network topology 310.

[0072] After that, the processor 104 can label the member nodes 12, 22 as belonging to the updated nodes in step S640. In this case, the unupdated nodes will be adjusted accordingly to include 13, 23, 32, 33, 34. Then, the processor 104 can increase i by 1 (i.e., i = 2) in step S650 and return to step S620.

[0073] Please refer to Figure 7B In the case where i is equal to 2, the processor 104 can obtain the first reference node marked as belonging to the updated node in the first (i.e., i - 1) stage. Since the member nodes 12 and 22 are marked as updated nodes in the first stage, the processor 104 can accordingly determine the member nodes 12 and 22 as the first reference nodes considered in the second stage.

[0074] After that, the processor 104 can determine in step S620 whether the signal scanning results of the member nodes 12 and 22 indicate the existence of a third member node in the unupdated nodes (e.g., member nodes 13, 23, 32, 33, 34).

[0075] In Figure 7B Since the member node 13 is within the signal transmission range corresponding to the member node 12, the signal strength of the member node 13 in the signal scanning result of the member node 12 should not be lower than the preset strength threshold. In this case, the processor 104 can determine that the signal quality index of the member node 13 in the signal scanning result of the member node 12 meets the first preset condition, and further determine the member node 13 as the third member node corresponding to the member node 12.

[0076] In addition, since the member node 23 is within the signal transmission range corresponding to the member node 22, the signal strength of the member node 23 in the signal scanning result of the member node 22 should not be lower than the preset strength threshold. In this case, the processor 104 can determine that the signal quality index of the member node 23 in the signal scanning result of the member node 22 meets the first preset condition, and further determine the member node 23 as the third member node corresponding to the member node 22.

[0077] Based on this, when i is 2, the determination result of the processor 104 in step S620 should be "yes", and it can continue to execute step S630 to update the tree network topology 310 by controlling each third member node to be directly connected to the corresponding first reference node.

[0078] In Figure 7B In this scenario, the processor 104 can control the member node 13 to be directly connected to the corresponding first reference node (i.e., the member node 12), and control the member node 23 to be directly connected to the corresponding first reference node (i.e., the member node 22) to update the tree network topology 310.

[0079] After that, the processor 104 may mark the member nodes 13 and 23 as belonging to the updated nodes in step S640. In this case, the unupdated nodes will be adjusted accordingly to include 32, 33, and 34. Then, the processor 104 may increment i by 1 (i.e., i = 3) in step S650 and return to step S620.

[0080] When i is equal to 3, the processor 104 may obtain the first reference node marked as belonging to the updated nodes in the second (i.e., i - 1) stage. Since the member nodes 13 and 23 are marked as updated nodes in the second stage, the processor 104 may accordingly determine the member nodes 13 and 23 as the first reference nodes considered in the third stage.

[0081] After that, the processor 104 may determine in step S620 whether the signal scanning results of the member nodes 13 and 23 indicate the existence of a third member node in the unupdated nodes (e.g., the member nodes 32, 33, and 34).

[0082] From Figure 7B it can be seen that the signal strengths of the member nodes 13 and 23 do not reach the preset strength threshold for the member nodes 32, 33, and 34. Therefore, the determination result of the processor 104 in step S620 should be "no". In this case, the member nodes 32, 33, and 34 can be referred to as Figure 7C the remote nodes as shown, and the processor 104 may process these remote nodes by implementing the means of the third embodiment (i.e., steps S660 to S680) to integrate these remote nodes into the tree network topology 310 in a more suitable manner.

[0083] From another perspective, the processor 104 may also be understood as, when determining that the unupdated nodes only include remote nodes not located within the signal transmission range of any updated node, accordingly processing these remote nodes by implementing the means of the third embodiment (i.e., steps S660 to S680), but it is not limited thereto.

[0084] In step S660, in the i-th stage, the processor 104 finds the second reference nodes among the unupdated nodes, where the signal scanning results of each second reference node include the fourth member nodes belonging to the updated nodes.

[0085] In step S670, the processor 104 updates the tree network topology by controlling each second reference node to be directly connected to the corresponding fourth member node.

[0086] In step S680, the processor 104 marks each second reference node as belonging to the updated nodes, increments i by 1, and returns to step S660.

[0087] In the third embodiment, the processor 104 may recursively execute steps S660 to S680 until each member node is marked as an updated node.

[0088] To make the third embodiment easier to understand, the details of the third embodiment will be described below, Figures 8A to 8C where Figures 8A to 8C is an application scenario diagram illustrated according to the third embodiment of the present invention.

[0089] In Figure 8A the scenario shown may be the same as that in Figure 7C i.e., the scenario where i is equal to 3. In this case, when executing step S660, the processor 104 may find the second reference node among the member nodes 32, 33, 34 (i.e., unupdated nodes).

[0090] In Figure 8A the scenario, assuming that the signal scanning result of the member node 32 only includes the member node 31 belonging to the updated nodes, the processor 104 may determine the member node 31 as the fourth member node corresponding to the member node 32. In another embodiment, assuming that the signal scanning result of the member node 32 further includes other updated nodes, the processor 104 may select one with the best signal quality index (e.g., the highest signal strength and higher than the signal strength lower limit value (e.g., -70 dBm or SNR 35 dB)) from these updated nodes as the fourth member node corresponding to the member node 32, but it is not limited thereto.

[0091] In addition, assuming that the signal scanning result of the member node 33 also only includes the member node 31 belonging to the updated nodes, the processor 104 may also determine the member node 31 as the fourth member node corresponding to the member node 33. In another embodiment, assuming that the signal scanning result of the member node 33 further includes other updated nodes, the processor 104 may select the one with the highest signal strength and higher than the signal strength lower limit value from these updated nodes as the fourth member node corresponding to the member node 33, but it is not limited thereto.

[0092] In Figure 8A since both the member nodes 32 and 33 have corresponding fourth member nodes (i.e., the member node 31), the processor 104 may determine the member nodes 32 and 33 as the second reference nodes considered in step S660.

[0093] After that, the processor 104 may execute step S670 to control the member node 32 to be directly connected to the corresponding fourth member node (i.e., the member node 31), and control the member node 33 to be directly connected to the corresponding fourth member node (i.e., the member node 31), so as to update the tree network topology 310 to Figure 8A the state shown.

[0094] Next, the processor 104 may execute step S680 to label the member nodes 32 and 33 as belonging to the updated nodes, increment i by 1 (i.e., i = 4), and return to step S660.

[0095] Please refer to Figure 8B , which corresponds to the situation where i is equal to 4, for example. In this case, when executing step S660, the processor 104 may find the second reference node in the member node 34 (i.e., the unupdated node).

[0096] In Figure 8B the situation, assuming that the signal scanning result of the member node 34 only includes the member node 32 belonging to the updated nodes, the processor 104 may determine that the member node 32 is the fourth member node corresponding to the member node 34. In another embodiment, assuming that the signal scanning result of the member node 34 further includes other updated nodes, the processor 104 may select, from these updated nodes, the one with the highest signal strength and higher than the signal strength lower limit value as the fourth member node corresponding to the member node 34, but it is not limited thereto.

[0097] In Figure 8B , since the member node 34 has a corresponding fourth member node (i.e., the member node 32), the processor 104 may determine that the member node 34 is the second reference node considered in step S660.

[0098] After that, the processor 104 may execute step S670 to control the member node 34 to be directly connected to the corresponding fourth member node (i.e., the member node 32) to update the tree network topology 310 to the Figure 8B shown state.

[0099] Next, the processor 104 may execute step S680 to label the member node 34 as belonging to the updated nodes. At this time, since each member node has been labeled as an updated node, the processor 104 may determine that the content of the third embodiment has been completed and may no longer recursively execute steps S660 to S680, but it is not limited thereto.

[0100] In this case, the fully updated tree network topology 310 may have the Figure 8C shown state. As can be seen from Figure 3 and Figure 8C , in the updated tree network topology 310, the member node 13 is adjusted from being directly connected to the control node 100 to being indirectly connected to the control node 100 through the member nodes 12 and 11 in sequence. Similarly, the member node 22 is adjusted from being directly connected to the control node 100 to being indirectly connected to the control node 100 through the member node 21.

[0101] Therefore, in Figure 8C the member nodes 13 and 22 can obtain better transmission quality and / or reliability. In addition, since the member nodes 32, 33, and 34 (i.e., the above-mentioned remote nodes) are relatively far from the control node 100 and the member nodes of other non-remote nodes, in the initial tree network topology determined in step S210, the member nodes 32, 33, and 34 may be connected to the control node 100 in a relatively inappropriate manner.

[0102] However, since the embodiments of the present invention can determine a better connection method for the above-mentioned remote nodes through the third embodiment, the transmission quality and / or reliability of each remote node can also be preferably ensured.

[0103] To make the above concept clearer, the following is supplemented with Figures 9A to 9E for illustration, where Figures 9A to 9E is a schematic diagram of an inappropriate connection method of each remote node illustrated according to the embodiments of the present invention.

[0104] In Figure 9A , it is assumed that the member node 34 is arranged to be connected to the control node 100 through the member node 31 in step S210. In this case, the member node 34 may not be able to achieve better transmission quality and / or reliability due to the too long distance between the member node 34 and the member node 31.

[0105] In Figure 9B , it is assumed that the member node 34 is arranged to be connected to the control node 100 through the member node 33 in step S210. In this case, the member node 34 may not be able to achieve better transmission quality and / or reliability due to the too long distance between the member node 34 and the member node 33.

[0106] In Figure 9C , it is assumed that the member node 32 is arranged to be connected to the control node 100 through the member nodes 34 and 31 in sequence in step S210. In this case, the member node 34 may not be able to achieve better transmission quality and / or reliability due to the too long distance between the member node 34 and the member node 31. In addition, the member node 32 may also have a longer transmission delay due to being connected to the control node 100 in a relatively inappropriate manner.

[0107] In Figure 9D , it is assumed that the member node 33 is arranged to be connected to the control node 100 through the member nodes 34 and 31 in sequence in step S210. In this case, the member node 34 may not be able to achieve better transmission quality and / or reliability due to the too long distance between the member node 34 and the member node 31. In addition, the member node 33 may also have a longer transmission delay due to being connected to the control node 100 in a relatively inappropriate manner.

[0108] In Figure 9E it is assumed that member nodes 32 and 33 are both arranged to sequentially connect to the control node 100 via member nodes 34 and 31 in step S210. In this case, the distance between member node 34 and member node 31 may be too long, resulting in member node 34 being unable to achieve better transmission quality and / or reliability. Additionally, member nodes 32 and 33 may also experience longer transmission delays due to connecting to the control node 100 in a less appropriate manner.

[0109] However, in an embodiment of the present invention, since each remote node (such as member nodes 32, 33, and 34) can be connected to the control node 100 in a better manner via the third embodiment, each remote node can achieve better transmission quality and / or reliability.

[0110] In some embodiments, the control node 100 may execute the Figure 2 shown method each time it obtains the signal scanning result of one or more of the multiple network nodes to update the tree network topology 310 regularly / irregularly.

[0111] In an embodiment of the present invention, when a member node operating as a relay node (i.e., a parent node) fails or for other reasons and cannot normally serve the corresponding child node, it may seriously affect the operation of itself and the child node.

[0112] Therefore, an embodiment of the present invention also proposes a method for maintaining the tree network topology, which can be used to solve the above technical problems.

[0113] Please refer to Figure 10 , which shows a method for maintaining the tree network topology according to the fourth embodiment of the present invention. The method of this embodiment can be executed by any member node (hereinafter referred to as the first member node) in the multi-hop wireless network system 300.

[0114] In the fourth embodiment, the first member node can be connected to the control node 100 among the multiple network nodes through a first relay node and operate as a second relay node. In other words, the first member node can operate as a child node of the first relay node and can also operate as a second relay node (i.e., a parent node) of other member nodes (such as the second member node among the multiple network nodes).

[0115] It should be understood that Figure 10 the first and second member nodes mentioned in subsequent embodiments and Figures 1 to 9E the first and second member nodes mentioned in Figure 10In subsequent embodiments, the so-called first and second member nodes can be simply understood as any two member nodes in the multi-hop wireless network system 300, but are not limited thereto.

[0116] In one embodiment, the first member node operating as the second relay node can be connected to the wireless terminal interface of the second member node through the access point interface of the first member node to operate as the second relay node of the second member node.

[0117] In addition, the first member node can also operate as a wireless terminal served by the first relay node. That is, the first member node can be connected to the access point interface of the first relay node through the wireless terminal interface of the first member node, and the first relay node can provide access point functions and operate as the access point of the first member node.

[0118] In the fourth embodiment, the first member node can determine whether the connection between the first relay node and the first member node is disconnected. In one embodiment, the first member node can determine whether the connection between its wireless terminal interface and the access point interface of the first relay node is disconnected. If so, the first member node can determine that the connection between the first relay node and the first member node is disconnected. In addition, in one embodiment, if the first member node determines that there is a beacon miss between it and the first relay node, the first member node can determine that the connection between the first relay node and the first member node is disconnected, but is not limited thereto.

[0119] In Figure 10 In step S1010, in response to determining that the connection between the first relay node and the first member node is disconnected, the first member node stops operating as the second relay node. In the fourth embodiment, the first member node can stop operating as the second relay node (for the second member node and / or other member nodes) by disabling the access point interface of the first member node.

[0120] From another perspective, when the first member node determines that the connection between it and the corresponding parent node is disconnected, it can immediately disable the access point function provided by the first member node, thereby temporarily preventing the first member node from operating as the parent node / access point of other member nodes. In this case, the second member node that regards the first member node as the parent node will also determine that the connection between it and the first member node is disconnected, and thus will also disable the access point function provided by the second member node. In other words, the second member node will also temporarily stop operating as the parent node / access point of other member nodes.

[0121] Based on this, it is possible to prevent the child node from misunderstanding that the parent node can still normally provide the access point function, and further enable the child node to attempt to change to other member nodes that can normally provide the access point function as the (new) parent node. Thereby, the transmission ability of the child node can be maintained, and further, the transmission efficiency of the tree network topology can be more guaranteed.

[0122] To make the concept of the fourth embodiment easier to understand, the following is further supplemented with Figures 11A to 11C for further explanation, where Figures 11A to 11C is an application scenario diagram illustrated according to the fourth embodiment of the present invention.

[0123] In Figure 11A , it is assumed that the control node 100 establishes a tree network topology 1110 through the mechanism of the previous embodiment, where the member node 13 operates as a relay node for the member node 14, the member node 11 operates as a relay node for the member node 13, and the member node 12 is directly connected to the control node 100.

[0124] In the fourth embodiment, it is assumed that the member node 13 corresponds to Figure 10 the first member node mentioned, but it is only for example and not for limiting the possible implementation manners of the present invention. In this case, the member node 11 can be understood as Figure 10 the first relay node in , and the member node 14 can be understood as the second member node served by the member node 13, but it is not limited thereto.

[0125] In Figure 11A , it is assumed that the distance between the member node 13 and the control node 100 exceeds the connection distance threshold. In this case, the member node 13 can be regarded as physically unable to be directly connected to the control node 100, so it must be connected to the control node 100 through other relay nodes. In addition, the distance between the member node 14 and the control node 100 is also assumed to exceed the connection distance threshold, so the member node 14 must also be connected to the control node 100 through other relay nodes.

[0126] In Figure 11B , it is assumed that the member node 11 fails to operate normally due to some reasons (such as being unable to provide the access point function), then the member node 13 can accordingly determine that the connection between the member node 11 and the member node 13 is disconnected according to the previous teachings. In this case, the member node 13 can accordingly stop operating as a relay node for other member nodes (such as the member node 14) (corresponding to step S1010). For example, the member node 13 can stop providing the access point function by disabling its own access point interface, but it is not limited thereto.

[0127] Similarly, the member node 14 can also correspondingly determine that the connection between the member node 14 and the member node 13 is disconnected according to the previous teachings. In this case, the member node 14 can also correspondingly stop operating as a relay node for other member nodes. For example, the member node 14 can also stop providing the access point function by disabling its own access point interface, but it is not limited thereto.

[0128] Next, the member nodes 14 and 13 will attempt to find a new relay node. In Figure 11C , after obtaining the signal scanning result provided by the member node 14, the control node 100 can control the member node 14 to connect to the member node 12 according to the teachings of the previous embodiments (such as the second and / or third embodiments). In this case, the member node 14 can regard the member node 12 as a relay node (i.e., the parent node), and can operate as a relay node for other member nodes again by enabling the access point interface of the member node 14.

[0129] In Figure 11D , after obtaining the signal scanning result provided by the member node 13, the control node 100 can control the member node 13 to connect to the member node 14 according to the teachings of the previous embodiments (such as the second and / or third embodiments). In this case, the member node 13 can regard the member node 14 as a relay node (i.e., the parent node), and can operate as a relay node for other member nodes again by enabling the access point interface of the member node 13.

[0130] In an embodiment, if the member node 13 fails to immediately stop operating as a relay node (e.g., disable the access point interface) when determining that the connection between the member node 11 and the member node 13 is disconnected, it will cause the member node 14 served by the member node 13 to be unable to immediately switch to another member node as a relay node. In this case, it will correspondingly cause the member node 13 to also be unable to immediately switch to another member node as a relay node. In other words, the member nodes 13 and 14 will continue to be trapped in Figure 11B the situation shown.

[0131] When the member nodes 13 and 14 are trapped in Figure 11B the situation shown, in addition to being unable to obtain the relevant data of the mesh network through the relay node itself, the member node 13 will also cause the member node 14 it serves to be unable to obtain the relevant data of the mesh network. In this case, only when the member node 11 resumes normal operation can the member node 13 use the member node 11 as a relay node again, and then operate normally in the Figure 11A architecture shown.

[0132] In addition, if member node 13 fails to immediately stop operating as a relay node (e.g., disable the access point interface) when it determines that the connection between member node 11 and member node 13 is disconnected, member node 13 may also switch to using member node 14 as a relay node. In other words, member nodes 13 and 14 may be parent and child nodes of each other. In this case, member nodes 13 and 14 still cannot obtain the relevant data of the mesh network and thus still cannot operate properly.

[0133] However, through Figures 11A to 11D the mechanism shown, the above situation can be avoided, thus better maintaining the performance of the tree network topology 1110.

[0134] In summary, the technical solution of the embodiment of the present invention can update the tree network topology based on the signal scanning results of each network node after determining the initial tree network topology, so that each member node can be connected to the control node in a better way. Thereby, better transmission quality and / or reliability can be achieved for each member node.

[0135] In addition, the embodiment of the present invention also proposes a technical solution that enables a member node to immediately stop operating as a relay node when it determines that the connection between it and the corresponding relay node is disconnected. Thereby, the member node and other member nodes it originally served can immediately switch to using other member nodes as relay nodes, thus avoiding the situation of being unable to obtain the relevant data of the mesh network for a long time and achieving the effect of maintaining the performance of the tree network topology.

[0136] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements for some or all of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for updating a network topology, which is executed by a control node among multiple network nodes, characterized in that, it includes: establishing a tree-like network topology including the multiple network nodes; obtaining the signal scanning results of each of the network nodes, where the signal scanning results of each of the network nodes indicate the signal quality indicators of at least one other network node; and updating the tree-like network topology based on the signal scanning results of each of the network nodes.

2. The method according to claim 1, wherein the multiple network nodes include the control node and at least one member node.

3. The method according to claim 2, wherein each of the member nodes is directly connected to the control node in the tree-like network topology, or is indirectly connected to the control node through other member nodes, wherein, the control node directly or indirectly obtains the signal scanning results of each of the member nodes through the tree-like network topology.

4. The method according to claim 2, wherein the step of updating the tree-like network topology based on the signal scanning results of each of the network nodes includes: in response to determining that the signal scanning result of the control node indicates that there are at least one first member node and at least one second member node among the at least one member node, updating the tree-like network topology by controlling each of the first member nodes to be directly connected to the control node, where the signal quality indicator of each of the first member nodes in the signal scanning result of the control node satisfies a first preset condition, and the signal quality indicator of each of the second member nodes in the signal scanning result of the control node does not satisfy the first preset condition; marking the at least one first member node as belonging to at least one updated node, and marking the at least one second member node as belonging to at least one unupdated node.

5. The method according to claim 4, wherein the step of updating the tree-like network topology based on the signal scanning results of each of the network nodes further includes: (a) In the i-th stage, obtaining at least one first reference node marked as belonging to the at least one updated node in the (i - 1)-th stage, where i is an index value greater than or equal to 1; (b) determining whether the signal scanning result of each of the first reference nodes indicates that there is at least one third member node among the at least one unupdated node, where the signal quality indicator of each of the third member nodes in the signal scanning result of the corresponding first reference node satisfies the first preset condition; (c) in response to determining that the signal scanning result of each of the first reference nodes indicates that there is at least one third member node among the at least one unupdated node, performing: updating the tree-like network topology by controlling each of the third member nodes to be directly connected to the corresponding first reference node; marking the at least one third member node as belonging to the at least one updated node; and increasing i by 1 and returning to step (a).

6. The method according to claim 5, wherein in response to determining that the signal scanning result of each of the first reference nodes indicates that no third member node exists in the at least one unupdated node, the method further comprises: (d) In the i-th stage, finding at least one second reference node in the at least one unupdated node, wherein the signal scanning result of each of the second reference nodes includes at least one fourth member node belonging to the at least one updated node; (e) Updating the tree network topology by controlling each of the second reference nodes to be directly connected to the corresponding at least one fourth member node; (f) Marking each of the second reference nodes as belonging to the at least one updated node, incrementing i by 1, and returning to step (d); and (g) Repeating steps (d) to (f) until each of the member nodes is marked as belonging to the at least one updated node.

7. The method according to claim 5, wherein when i is 1, the step of obtaining the at least one first reference node marked as belonging to the at least one updated node in the (i - 1)-th stage comprises: Determining the at least one first member node as the at least one first reference node.

8. The method according to claim 2, wherein the tree network topology belongs to a multi-hop wireless network, and each of the member nodes is connected to an external network only through the control node.

9. The method according to claim 2, wherein the control node is a multi-point repeater, and each of the member nodes is a mesh access point.

10. The method according to claim 1, wherein the control node is predefined or determined by a competition mechanism among the multiple network nodes.

11. The method according to claim 2, wherein the at least one member node includes at least one updated node and at least one unupdated node, and the step of updating the tree network topology based on the signal scanning result of each of the network nodes comprises: In response to determining that the at least one unupdated node only includes at least one remote node not located within the signal transmission range of any updated node, repeating the following operations until each of the member nodes is marked as belonging to the at least one updated node, the operations including: Finding at least one second reference node in the at least one unupdated node, wherein the signal scanning result of each of the second reference nodes includes at least one fourth member node belonging to the at least one updated node, and the signal transmission range corresponds to a preset intensity threshold; Updating the tree network topology by controlling each of the second reference nodes to be directly connected to the corresponding at least one fourth member node; Marking each of the second reference nodes as belonging to the at least one updated node.

12. A control node, characterized in that, comprises: A storage circuit that stores program code; and A processor coupled to the storage circuit and accessing the program code to perform: Establishing a tree network topology including the multiple network nodes; Obtain the signal scanning results of each of the network nodes, where the signal scanning results of each of the network nodes indicate the signal quality metrics of at least one other network node; and Update the tree-shaped network topology based on the signal scanning results of each of the network nodes.

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