Self-adaptive time synchronization method of multi-cluster ad hoc network and multi-cluster ad hoc network

Abstract

The invention discloses an adaptive time synchronization method of a multi-cluster ad hoc network and the multi-cluster ad hoc network. The method comprises the following steps: initializing a time slot structure; the inter-cluster cluster head node adopts a first time slot sequence, the intra-cluster cluster head node adopts a second time slot sequence, and the non-networked common node adopts a third time slot sequence; the common node of the intra-cluster network where the inter-cluster cluster head node is located performs time synchronization on the inter-cluster cluster head node and then is adjusted into a first time slot sequence; performing time synchronization on the cluster head nodes in the corresponding clusters by the common nodes of the other intra-cluster networks, and then adjusting the cluster head nodes into second time slot sequences; and the intra-cluster cluster head node completing intra-cluster network time synchronization determines the total number of nodes, first local time and a first synchronization time difference with the inter-cluster cluster head node to generate a whole network time synchronization signaling message, so that all nodes of the intra-cluster network perform time synchronization on the inter-cluster cluster head node at the same moment and then are adjusted into a first time slot sequence. According to the invention, the stability of each cluster of networking can be ensured while the time synchronization of the whole network is completed.

Description

Technical Field

[0001] The present invention relates to the technical field related to wireless ad hoc networks, and in particular to an adaptive time synchronization method for a multi-cluster ad hoc network and the multi-cluster ad hoc network. Background Art

[0002] A multi-cluster ad hoc network refers to a wireless communication ad hoc network in which communication nodes are divided into different communication groups according to factors such as space, frequency, and time slots. Group members belong to the same intra-cluster network and are called intra-cluster nodes. In each intra-cluster network, there is a cluster head node, which is responsible for initiating and managing the communication of the intra-cluster network, and together with the cluster head nodes of other intra-cluster networks, forms an inter-cluster network, which is also called an inter-cluster node. In the inter-cluster network, there is also an inter-cluster cluster head node, whose function is to initiate and manage the communication of the inter-cluster network. The inter-cluster network occupies different frequency bands for communication with each intra-cluster network.

[0003] In multi-cluster self-organizing networks, cluster head nodes are usually used as time reference stations. Ordinary nodes in an intra-cluster network synchronize time with the cluster head node of the cluster to achieve intra-cluster networking; similarly, ordinary nodes in an inter-cluster network also need to synchronize time with the inter-cluster head node to achieve inter-cluster networking. However, the networking initiation time of different clusters is usually different. The cluster head node is both a member of the inter-cluster network and a member of the intra-cluster network. If the intra-cluster network and the inter-cluster network exist at the same time, the local time of the cluster head node will conflict; if the cluster head node directly synchronizes time in either the intra-cluster network or the inter-cluster network, it will affect the networking stability of the other network, and the node will be offline due to the time synchronization difference; the intra-cluster network communication time slot and the inter-cluster network communication time slot of the node are usually time-divided. When time synchronization has not been completed, the intra-cluster and inter-cluster communication time slots of different nodes in the same cluster may be completely staggered, resulting in the inability to complete time synchronization. Therefore, a reasonable and efficient time synchronization method is needed in multi-cluster self-organizing networks to solve the time difference problem of different clusters and ensure the stability of each cluster network while completing the time synchronization of the entire network. Summary of the invention

[0004] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, the present invention proposes an adaptive time synchronization method for multi-cluster self-organizing networks, which can solve the time difference problem of different clusters and ensure the stability of each cluster network while completing the time synchronization of the entire network.

[0005] The present invention also provides a multi-cluster self-organizing network, a control device for executing the self-adaptive time synchronization method of the multi-cluster self-organizing network, and a computer-readable storage medium.

[0006] According to the adaptive time synchronization method of a multi-cluster self-organizing network of the first aspect of the present invention, the multi-cluster self-organizing network includes multiple groups of intra-cluster networks and one group of inter-cluster networks, each group of the intra-cluster networks includes an intra-cluster cluster head node, the inter-cluster network includes an inter-cluster cluster head node, the inter-cluster cluster head node is one of all the intra-cluster cluster head nodes, and the inter-cluster cluster head node is a time reference station, the method includes: Initialize the time slot structure of each node in the multi-cluster self-organizing network; wherein the inter-cluster cluster head node adopts the first time slot sequence, each intra-cluster cluster head node adopts the second time slot sequence, and the common nodes in each intra-cluster network that are not connected to the network adopt the third time slot sequence; the first time slot sequence and the second time slot sequence both include inter-cluster time slots and intra-cluster time slots that alternate with equal-length periods, and the period of the inter-cluster time slots and intra-cluster time slots in the second time slot sequence is at least twice the period of the inter-cluster time slots and intra-cluster time slots in the first time slot sequence, and the third time slot sequence includes intra-cluster time slots; The common nodes in the intra-cluster network where the inter-cluster cluster head node is located perform time synchronization with the inter-cluster cluster head node, and adjust the time slot structure to the first time slot sequence after the synchronization is completed; The remaining common nodes of each intra-cluster network perform time synchronization with the corresponding intra-cluster head node, and adjust the time slot structure to the second time slot sequence after the synchronization is completed; The cluster head node within the cluster that has completed the time synchronization of the intra-cluster network determines the total number of nodes in the intra-cluster network, the first local time, and the first synchronization time difference with the inter-cluster cluster head node, so as to generate a full-network time synchronization signaling message and send it to each ordinary node in the intra-cluster network, so that all nodes in the intra-cluster network perform time synchronization with the inter-cluster cluster head node at the same time, and adjust the time slot structure to the first time slot sequence after the synchronization is completed.

[0007] The adaptive time synchronization method for a multi-cluster ad hoc network according to an embodiment of the present invention has at least the following beneficial effects: In order to avoid the inability to complete time synchronization due to the complete misalignment of the communication time slots between clusters of different nodes, an embodiment of the present invention first initializes the time slot structure of each node in the multi-cluster self-organizing network, so that the cluster head node between clusters adopts the first time slot sequence, the cluster head node within each cluster adopts the second time slot sequence, and the ordinary nodes not connected to the network in each cluster network adopt the third time slot sequence, and then firstly complete the time synchronization of each cluster network, and after the synchronization is completed, adaptively adjust the time slot structure to be the same as that of the cluster head node within the cluster, and then enable the cluster head node within each cluster to generate a full-network time synchronization signaling message and send it to each ordinary node of the corresponding cluster network, so that all nodes of the network within the cluster perform time synchronization with the cluster head node between clusters at the same time, which can solve the time difference problem of different clusters and ensure the stability of each cluster network while completing the full-network time synchronization.

[0008] According to some embodiments of the present invention, in the process of initializing the time slot structure of each node in the multi-cluster self-organizing network, the cluster head node in the cluster that does not need intra-cluster networking adopts a fourth time slot sequence, and the fourth time slot sequence includes inter-cluster time slots; The method further comprises: The intra-cluster cluster head node that does not require intra-cluster networking performs time synchronization with the inter-cluster cluster head node, and adjusts the time slot structure to the first time slot sequence after the synchronization is completed.

[0009] According to some embodiments of the present invention, the network-wide time synchronization signaling message is obtained by the following steps: Determine a synchronization initiation time according to the total number of nodes and the first local time; The whole-network time synchronization signaling message is generated according to the synchronization initiation time and the first synchronization time difference.

[0010] According to some embodiments of the present invention, the first synchronization time difference is obtained by the following steps: Acquire the first local time and the reference time of the cluster head node between the clusters; The first synchronization time difference is obtained according to the first local time and the reference time.

[0011] According to some embodiments of the present invention, the common nodes in the intra-cluster network where the inter-cluster cluster head node is located perform time synchronization with the inter-cluster cluster head node, including: Acquire a first reference network establishment initiation time of the inter-cluster cluster head node, and a first common network establishment initiation time and a second local time of each common node of the intra-cluster network where the inter-cluster cluster head node is located; Determine a second synchronization time difference between each common node and the inter-cluster cluster head node according to each of the first common network establishment initiation times and the first reference network establishment initiation time; The second local time of each common node is adjusted based on each second synchronization time difference to synchronize with the inter-cluster head node.

[0012] According to some embodiments of the present invention, the remaining common nodes of each intra-cluster network perform time synchronization with the corresponding intra-cluster head node, including: Acquire the second reference network establishment initiation time of each of the cluster head nodes in the remaining cluster networks, and the second common network establishment initiation time and the third local time of each of the corresponding common nodes in the cluster network; Determine a third synchronization time difference between each common node and the corresponding cluster head node in the cluster according to each of the second common network establishment initiation times and the second reference network establishment initiation times; The third local time of each common node is adjusted based on each third synchronization time difference to synchronize with the corresponding cluster head node in the cluster.

[0013] According to some embodiments of the present invention, the intra-cluster cluster head node that does not require intra-cluster networking performs time synchronization with the inter-cluster cluster head node, including: Acquire a first reference network establishment initiation time of the inter-cluster cluster head node, and a third reference network establishment initiation time and a fourth local time of the intra-cluster cluster head node that does not require intra-cluster networking; Determine, according to the first reference network establishment initiation time and the third reference network establishment initiation time, a fourth synchronization time difference between the cluster head node within the cluster that does not require intra-cluster networking and the cluster head node between clusters; The fourth local time of the cluster head node within the cluster that does not require intra-cluster networking is adjusted based on the fourth synchronization time difference to be synchronized to the inter-cluster cluster head node.

[0014] According to some embodiments of the present invention, the initializing the time slot structure of each node in the multi-cluster ad hoc network includes: Determining the node status of each initial node in the multi-cluster ad hoc network; If the node state indicates that the initial node is the inter-cluster head node, adjusting the time slot structure of the inter-cluster head node to the first time slot sequence; If the node state indicates that the initial node is a cluster head node in the cluster, adjusting the time slot structure of the cluster head node in the cluster to the second time slot sequence; If the node status indicates that the initial node is a common node that has not joined the network, the time slot structure of the common node is adjusted to the third time slot sequence.

[0015] According to some embodiments of the present invention, after determining the node status of each initial node in the multi-cluster ad hoc network, the method further includes: If the node status indicates that the initial node is the cluster head node in the cluster that does not require intra-cluster networking, the time slot structure of the cluster head node in the cluster that does not require intra-cluster networking is adjusted to a fourth time slot sequence, and the fourth time slot sequence includes inter-cluster time slots.

[0016] According to the multi-cluster self-organizing network of the second aspect embodiment of the present invention, the multi-cluster self-organizing network is used to implement the adaptive time synchronization method of the multi-cluster self-organizing network as described in the first aspect embodiment. Since the multi-cluster self-organizing network adopts all the technical solutions of the adaptive time synchronization method of the multi-cluster self-organizing network of the above embodiment, it at least has all the beneficial effects brought by the technical solutions of the above embodiment.

[0017] According to the third aspect of the present invention, the control device comprises a memory, a processor and a computer program stored in the memory and executable on the processor, and the processor implements some steps of the adaptive time synchronization method for multi-cluster self-organizing networks as described in the first aspect of the present invention when executing the computer program. Since the control device adopts all the technical solutions of the adaptive time synchronization method for multi-cluster self-organizing networks of the above embodiment, it has at least all the beneficial effects brought by the technical solutions of the above embodiment.

[0018] The computer-readable storage medium according to the fourth aspect of the present invention stores computer-executable instructions, and the computer-executable instructions are used to execute some steps in the method for adaptive time synchronization of multi-cluster self-organizing networks as described in the first aspect of the present invention. Since the computer-readable storage medium adopts all the technical solutions of the method for adaptive time synchronization of multi-cluster self-organizing networks of the above embodiment, it at least has all the beneficial effects brought by the technical solutions of the above embodiment.

[0019] Other features and advantages of the present invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which: Figure 1 is a schematic diagram of a multi-cluster ad hoc network according to an embodiment of the present invention; Figure 2 is a schematic diagram of a time slot structure according to an embodiment of the present invention; Figure 3 The present invention is a flowchart of a method for adaptive time synchronization in a multi-cluster ad hoc network according to an embodiment of the present invention. DETAILED DESCRIPTION

[0021] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0022] In the description of the present invention, if there is a description of first, second, etc., it is only for the purpose of distinguishing technical features, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features or implicitly indicating the order of the indicated technical features.

[0023] In the description of the present invention, it should be understood that descriptions involving orientation, such as orientation or positional relationship indicated as up, down, etc., are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0024] In the description of the present invention, it should be noted that, unless otherwise clearly defined, terms such as setting, installing, connecting, etc. should be understood in a broad sense, and technicians in the relevant technical field can reasonably determine the specific meanings of the above terms in the present invention in combination with the specific content of the technical solution.

[0025] The following will be combined Figures 1 to 3 The adaptive time synchronization method for a multi-cluster ad hoc network according to an embodiment of the present invention is described clearly and completely. Obviously, the embodiment described below is only a part of the embodiments of the present invention, but not all of the embodiments.

[0026] refer to Figures 1 to 3 , Figure 1 is a schematic diagram of a multi-cluster ad hoc network according to an embodiment of the present invention, Figure 2 is a schematic diagram of a time slot structure according to an embodiment of the present invention, Figure 3 The present invention is a flowchart of a method for adaptive time synchronization in a multi-cluster ad hoc network according to an embodiment of the present invention.

[0027] According to the adaptive time synchronization method of a multi-cluster self-organizing network of the first aspect of the present invention, the multi-cluster self-organizing network includes multiple groups of intra-cluster networks and one group of inter-cluster networks, each group of intra-cluster networks includes intra-cluster head nodes, the inter-cluster networks include inter-cluster head nodes, the inter-cluster head nodes are one of all intra-cluster head nodes, and the inter-cluster head nodes are time reference stations. The method includes: Initialize the time slot structure of each node in the multi-cluster self-organizing network; wherein, the cluster head node between clusters adopts the first time slot sequence, the cluster head node within each cluster adopts the second time slot sequence, and the common nodes not connected to the network in each cluster network adopt the third time slot sequence; both the first time slot sequence and the second time slot sequence include inter-cluster time slots and intra-cluster time slots that alternate with equal-length periods, and the period of the inter-cluster time slots and intra-cluster time slots in the second time slot sequence is at least twice the period of the inter-cluster time slots and intra-cluster time slots in the first time slot sequence, and the third time slot sequence includes intra-cluster time slots; The common nodes in the intra-cluster network where the inter-cluster head node is located perform time synchronization with the inter-cluster head node, and adjust the time slot structure to the first time slot sequence after the synchronization is completed; The remaining common nodes in each cluster network perform time synchronization with the corresponding cluster head node in the cluster, and adjust the time slot structure to the second time slot sequence after the synchronization is completed; The cluster head node within the cluster that has completed the time synchronization of the intra-cluster network determines the total number of nodes in the intra-cluster network, the first local time, and the first synchronization time difference with the inter-cluster cluster head node to generate a full-network time synchronization signaling message and send it to each ordinary node in the intra-cluster network, so that all nodes in the intra-cluster network perform time synchronization with the inter-cluster cluster head node at the same time, and adjust the time slot structure to the first time slot sequence after the synchronization is completed.

[0028] In some embodiments of the present invention, in the process of initializing the time slot structure of each node in the multi-cluster ad hoc network, the cluster head node in the cluster that does not need intra-cluster networking adopts a fourth time slot sequence, and the fourth time slot sequence includes inter-cluster time slots; The method also includes: The cluster head node within the cluster that does not require intra-cluster networking performs time synchronization with the cluster head node between clusters, and adjusts the time slot structure to the first time slot sequence after the synchronization is completed.

[0029] In some embodiments of the present invention, initializing the time slot structure of each node in the multi-cluster ad hoc network includes: Determine the node status of each initial node in the multi-cluster ad hoc network; If the node state indicates that the initial node is an inter-cluster head node, then adjusting the time slot structure of the inter-cluster head node to a first time slot sequence; If the node state indicates that the initial node is a cluster head node in the cluster, then adjusting the time slot structure of the cluster head node in the cluster to a second time slot sequence; If the node state indicates that the initial node is a common node that has not joined the network, the time slot structure of the common node is adjusted to the third time slot sequence; If the node state indicates that the initial node is a cluster head node in a cluster that does not require intra-cluster networking, the time slot structure of the cluster head node in the cluster that does not require intra-cluster networking is adjusted to a fourth time slot sequence.

[0030] In order to avoid the inability to complete time synchronization due to the complete mismatch of intra-cluster and inter-cluster communication time slots of different nodes, the present invention implements different time slot sequences for nodes that have joined the network and nodes that have not joined the network, such as Figure 2 As shown, the specific time slot structure design principle is as follows: (1) Sequence 1 (i.e., the first time slot sequence) consists of inter-cluster time slots and intra-cluster time slots of equal length, alternating to ensure the normal operation of the inter-cluster network and the intra-cluster network. It is suitable for nodes that communicate both within and between clusters. Therefore, the cluster head node between clusters uses sequence 1, and other nodes also use sequence 1 after time synchronization with the cluster head node between clusters to ensure the consistency of the time slot structure. (2) Sequence 2 (i.e., the second time slot sequence) is composed of inter-cluster time slots and intra-cluster time slots of equal length, alternating with each other. Its period length is at least twice that of sequence 1. It is applicable to cluster head nodes within a cluster. This design takes into account that when time synchronization is not achieved, the time slots may be completely staggered. The synchronized nodes are using the intra-cluster (or inter-cluster) communication frequency, while the unsynchronized nodes are using the inter-cluster (or intra-cluster) communication frequency, resulting in the inability to receive the time synchronization signal. By extending the time slot period, it is ensured that the ability to receive the intra-cluster / inter-cluster time synchronization signal is available within any intra-cluster or inter-cluster time slot period of sequence 2, thereby completing time synchronization. After synchronization, there is no need to communicate through a longer time slot period, so sequence 1 can be used; (3) Sequence 3 (i.e., the fourth time slot sequence) consists entirely of inter-cluster time slots and is applicable to nodes that only communicate in the inter-cluster network. This node always receives the inter-cluster time synchronization signal to complete the inter-cluster time synchronization. After synchronization, in order to save resources, the inter-cluster head node can stop communicating when it is at the intra-cluster communication frequency point, reducing unnecessary communication time slots and using sequence 1. (4) Sequence 4 (i.e., the third time slot sequence) consists entirely of intra-cluster time slots and is applicable to nodes that only communicate within the cluster network. This node always receives the intra-cluster time synchronization signal, thereby completing intra-cluster time synchronization. When the cluster head node within the cluster is at the inter-cluster communication frequency point, it can stop communicating and use sequence 2; ultimately, inter-cluster time synchronization is completed (the reason is the same as synchronizing sequence 2 to sequence 1).

[0031] After all nodes have completed time synchronization, they all use sequence 1. The purpose is to ensure that the configurations of communication reception and transmission, frequency, rate, etc. of the entire network are all aligned, reduce unnecessary time slot configurations, reasonably allocate time slot resources, and ensure stable communication of the entire network.

[0032] refer to Figure 1 There are three sets of intra-cluster networks and one set of inter-cluster networks in the multi-cluster self-organizing network. The three sets of intra-cluster networks are represented as sets ,gather ,gather , the inter-cluster network is represented as a set , where the node , , are all cluster head nodes in the cluster, and nodes is the cluster head node, and the other nodes are ordinary nodes. It is the cluster head node within the cluster that does not require intra-cluster networking. The time reference station of the entire network is the inter-cluster cluster head node , eventually all nodes need to send messages to the cluster head node time to synchronize.

[0033] In the early stage of multi-cluster self-organizing network construction, each cluster network first synchronizes time with the cluster head node in its cluster, that is, the node To Node To synchronize time, nodes To Node To synchronize time, nodes Since there are no other nodes in the intra-cluster network, no intra-cluster synchronization process is required and the intra-cluster network synchronization is considered complete.

[0034] In some embodiments of the present invention, the common nodes in the intra-cluster network where the inter-cluster cluster head node is located perform time synchronization with the inter-cluster cluster head node, including: Acquire a first benchmark network establishment initiation time of the inter-cluster head node, and a first common network establishment initiation time and a second local time of each common node in the intra-cluster network where the inter-cluster head node is located; Determine a second synchronization time difference between each common node and the cluster head node between clusters according to each first common network establishment initiation time and the first reference network establishment initiation time; The second local time of each common node is adjusted based on each second synchronization time difference to synchronize with the cluster head node among the clusters.

[0035] In the collection In the initial network construction phase, the cluster head node in the cluster Considered as completing the whole network time synchronization, using sequence 1, ordinary node Not yet connected to the network, using sequence 4. The length of a single inter-cluster time slot and intra-cluster time slot is T ; The operation cycle within the cluster in sequence 1 is 2 T , the length is T , the operation cycle within the cluster in sequence 4 is T , the length is T ; Assume that the node The network construction initiation time is ,node With Node The synchronization time difference is , , it can be seen from the networking time slot sequence of each node that when the node When in the intra-cluster networking time slot, time to + T Must contain nodes The intra-cluster networking time slot, so the node Adjustable local time , Sync to Node After completing time synchronization, the node Switch to using sequence 1.

[0036] In some embodiments of the present invention, the remaining common nodes of each intra-cluster network perform time synchronization with the corresponding intra-cluster head node, including: Acquire the second reference network establishment initiation time of each cluster head node in each remaining cluster network, and the second common network establishment initiation time and the third local time of each corresponding common node in the cluster network; Determine a third synchronization time difference between each common node and a corresponding cluster head node in the cluster according to each second common network establishment initiation time and the second reference network establishment initiation time; The third local time of each common node is adjusted based on each third synchronization time difference to be synchronized to the corresponding cluster head node in the cluster.

[0037] In the collection In the initial network construction phase, the cluster head node in the cluster Considered as connected to the network, using sequence 2, ordinary node Not yet connected to the network, using sequence 4. The length of a single inter-cluster time slot and intra-cluster time slot is T ; The operation cycle within the cluster in sequence 2 is 4 T , length 2 T ; Assume that the node , The network construction initiation time is , ,node With Node The synchronization time difference is , when the node When in the intra-cluster networking time slot, time to +2 T Must contain nodes The intra-cluster networking time slot, so the node Adjustable local time Sync to Node After completing time synchronization, the node Switch to using sequence 2.

[0038] In some embodiments of the present invention, the cluster head node within the cluster that does not require intra-cluster networking performs time synchronization with the inter-cluster head node, including: Acquire a first reference network establishment initiation time of an inter-cluster cluster head node, and a third reference network establishment initiation time and a fourth local time of an intra-cluster cluster head node that does not require intra-cluster networking; Determine a fourth synchronization time difference between a cluster head node within a cluster that does not require intra-cluster networking and a cluster head node between clusters according to the first reference network establishment initiation time and the third reference network establishment initiation time; The fourth local time of the cluster head node in the cluster that does not require intra-cluster networking is adjusted based on the fourth synchronization time difference to be synchronized to the inter-cluster cluster head node.

[0039] In the collection In the node Using sequence 1, node Using sequence 2, node Use sequence 3. Assume that the node The network construction initiation time is ,node and The synchronization time difference is ,node and The synchronization time difference is When the node When in the inter-cluster networking time slot, time to + T Must contain nodes The inter-cluster networking time slot, and the node Must be to +2 T The inter-cluster networking time slot is run once within the time period, so the node , The synchronization time difference of the network can be obtained , At this point Node Complete time synchronization and switch to sequence 1, but the node Cannot directly send to the node Time synchronization is performed, otherwise the collection will The ordinary node in is offline.

[0040] gather , Time synchronization completed, only collection Need to synchronize time to nodes .

[0041] In some embodiments of the present invention, the network-wide time synchronization signaling message is obtained by the following steps: Determine a synchronization initiation time according to the total number of nodes and the first local time; A network-wide time synchronization signaling message is generated according to the synchronization initiation time and the first synchronization time difference.

[0042] In some embodiments of the present invention, the first synchronization time difference is obtained by the following steps: Obtain the first local time and the reference time of the cluster head node among the clusters; A first synchronization time difference is determined according to the first local time and the reference time.

[0043] In some embodiments, at this time, the node , The local time is +2T , the synchronization time difference is , the synchronization start time is +4 T .node Send the network-wide time synchronization signaling message to , when the synchronization is initiated +4 T Always adjust for time difference , so that the set The time of each node in the , thus avoiding abnormal node disconnection.

[0044] It should be noted that if there are more nodes, the same network-wide time synchronization signaling message is sent to each node, and +(2+2 N ) T Always adjust for time difference ,in, N Indicates the number of cycles required for all nodes to receive the network-wide time synchronization signaling message. At this point, the network-wide time synchronization is completed.

[0045] According to the adaptive time synchronization method for multi-cluster self-organizing networks of an embodiment of the present invention, in order to avoid the inability to complete time synchronization due to the complete misalignment of the intra-cluster and inter-cluster communication time slots of different nodes, the embodiment of the present invention first initializes the time slot structure of each node in the multi-cluster self-organizing network, so that the cluster head node between clusters adopts the first time slot sequence, the cluster head node within each cluster adopts the second time slot sequence, and the ordinary nodes not connected to the network in each cluster network adopt the third time slot sequence, and then firstly complete the time synchronization of each cluster network, and after the synchronization is completed, adaptively adjust the time slot structure to be the same as that of the cluster head node within the cluster, and then enable the cluster head node within each cluster to generate a full-network time synchronization signaling message and send it to each ordinary node of the corresponding intra-cluster network, so that all nodes of the intra-cluster network perform time synchronization with the inter-cluster cluster head node at the same time, which can solve the time difference problem of different clusters and ensure the stability of each cluster network while completing the full-network time synchronization.

[0046] According to the multi-cluster self-organizing network of the second aspect embodiment of the present invention, the multi-cluster self-organizing network is used to implement the adaptive time synchronization method of the multi-cluster self-organizing network of the first aspect embodiment. Since the multi-cluster self-organizing network adopts all the technical solutions of the adaptive time synchronization method of the multi-cluster self-organizing network of the above embodiment, it at least has all the beneficial effects brought by the technical solutions of the above embodiment.

[0047] In addition, an embodiment of the present invention further provides a control device, which includes: a memory, a processor, and a computer program stored in the memory and executable on the processor. The processor and the memory may be connected via a bus or other means.

[0048] The memory, as a non-transient computer-readable storage medium, can be used to store non-transient software programs and non-transient computer executable programs. In addition, the memory may include a high-speed random access memory, and may also include a non-transient memory, such as at least one disk storage device, a flash memory device, or other non-transient solid-state storage device. In some embodiments, the memory may optionally include a memory remotely disposed relative to the processor, and these remote memories may be connected to the processor via a network. Examples of the above-mentioned network include, but are not limited to, the Internet, an intranet, a local area network, a mobile communication network, and combinations thereof.

[0049] The non-transient software programs and instructions required to implement some steps in the adaptive time synchronization method for multi-cluster self-organizing networks in the above embodiment are stored in the memory, and when executed by the processor, some steps in the adaptive time synchronization method for multi-cluster self-organizing networks in the above embodiment are executed.

[0050] The device embodiments described above are merely illustrative, and the units described as separate components may or may not be physically separated, that is, they may be located in one place or distributed on multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0051] In addition, an embodiment of the present invention also provides a computer-readable storage medium, which stores computer-executable instructions, and the computer-executable instructions are executed by a processor or controller, for example, by the processor of the above-mentioned embodiment, so that the above-mentioned processor can execute some steps in the adaptive time synchronization method of multi-cluster self-organizing network in the above-mentioned embodiment.

[0052] It will be appreciated by those skilled in the art that all or some of the steps and systems in the methods disclosed above may be implemented as software, firmware, hardware, and appropriate combinations thereof. Some or all physical components may be implemented as software executed by a processor, such as a central processing unit, a digital signal processor, or a microprocessor, or as hardware, or as an integrated circuit, such as an application-specific integrated circuit. Such software may be distributed on a computer-readable medium, which may include a computer storage medium (or non-transitory medium) and a communication medium (or transient medium). As known to those skilled in the art, the term computer storage medium includes volatile and non-volatile, removable and non-removable media implemented in any method or technology for storing information (such as computer-readable instructions, data structures, program modules, or other data). Computer storage media include, but are not limited to, RAM, ROM, EEPROM, flash memory or other memory technology, CD-ROM, digital versatile disk (DVD) or other optical disk storage, magnetic cassettes, magnetic tapes, disk storage or other magnetic storage devices, or any other medium that can be used to store desired information and can be accessed by a computer. Furthermore, it is well known to those skilled in the art that communication media typically embodies computer readable instructions, data structures, program modules, or other data in a modulated data signal such as a carrier wave or other transport mechanism, and may include any information delivery media.

[0053] The embodiments of the present invention are described in detail above in conjunction with the accompanying drawings, but the present invention is not limited to the above embodiments, and various changes can be made within the knowledge scope of ordinary technicians in the relevant technical field without departing from the purpose of the present invention.

Claims

1. An adaptive time synchronization method for a multi-cluster self-organizing network, wherein the multi-cluster self-organizing network includes multiple groups of intra-cluster networks and one group of inter-cluster networks, each group of the intra-cluster networks includes an intra-cluster head node, the inter-cluster network includes an inter-cluster head node, the inter-cluster head node is one of all the intra-cluster head nodes, and the inter-cluster head node is a time reference station, characterized in that: The method comprises: Initialize the time slot structure of each node in the multi-cluster self-organizing network; wherein the inter-cluster cluster head node adopts the first time slot sequence, each intra-cluster cluster head node adopts the second time slot sequence, and the common nodes in each intra-cluster network that are not connected to the network adopt the third time slot sequence; the first time slot sequence and the second time slot sequence both include inter-cluster time slots and intra-cluster time slots that alternate with equal-length periods, and the period of the inter-cluster time slots and intra-cluster time slots in the second time slot sequence is at least twice the period of the inter-cluster time slots and intra-cluster time slots in the first time slot sequence, and the third time slot sequence includes intra-cluster time slots; The common nodes in the intra-cluster network where the inter-cluster cluster head node is located perform time synchronization with the inter-cluster cluster head node, and adjust the time slot structure to the first time slot sequence after the synchronization is completed; The remaining common nodes of each intra-cluster network perform time synchronization with the corresponding intra-cluster head node, and adjust the time slot structure to the second time slot sequence after the synchronization is completed; The cluster head node within the cluster that has completed the time synchronization of the intra-cluster network determines the total number of nodes in the intra-cluster network, the first local time, and the first synchronization time difference with the inter-cluster cluster head node, so as to generate a full-network time synchronization signaling message and send it to each ordinary node in the intra-cluster network, so that all nodes in the intra-cluster network perform time synchronization with the inter-cluster cluster head node at the same time, and adjust the time slot structure to the first time slot sequence after the synchronization is completed.

2. The method for adaptive time synchronization of a multi-cluster ad hoc network according to claim 1, characterized in that: In the process of initializing the time slot structure of each node in the multi-cluster self-organizing network, the cluster head node in the cluster that does not need intra-cluster networking adopts a fourth time slot sequence, and the fourth time slot sequence includes inter-cluster time slots; The method further comprises: The intra-cluster cluster head node that does not require intra-cluster networking performs time synchronization with the inter-cluster cluster head node, and adjusts the time slot structure to the first time slot sequence after the synchronization is completed.

3. The method for adaptive time synchronization of a multi-cluster ad hoc network according to claim 1, characterized in that: The network-wide time synchronization signaling message is obtained by the following steps: Determine a synchronization initiation time according to the total number of nodes and the first local time; The whole-network time synchronization signaling message is generated according to the synchronization initiation time and the first synchronization time difference.

4. The method for adaptive time synchronization of a multi-cluster ad hoc network according to claim 1 or 3, characterized in that: The first synchronization time difference is obtained by the following steps: Acquire the first local time and the reference time of the cluster head node between the clusters; The first synchronization time difference is obtained according to the first local time and the reference time.

5. The method for adaptive time synchronization of a multi-cluster ad hoc network according to claim 1, characterized in that: The common nodes in the intra-cluster network where the inter-cluster cluster head node is located perform time synchronization with the inter-cluster cluster head node, including: Acquire a first reference network establishment initiation time of the inter-cluster cluster head node, and a first common network establishment initiation time and a second local time of each common node of the intra-cluster network where the inter-cluster cluster head node is located; Determine a second synchronization time difference between each common node and the inter-cluster cluster head node according to each of the first common network establishment initiation times and the first reference network establishment initiation time; The second local time of each common node is adjusted based on each second synchronization time difference to synchronize with the inter-cluster head node.

6. The method for adaptive time synchronization of a multi-cluster ad hoc network according to claim 1, characterized in that: The remaining common nodes in each cluster network perform time synchronization with the corresponding cluster head node in the cluster, including: Acquire the second reference network establishment initiation time of each of the cluster head nodes in the remaining cluster networks, and the second common network establishment initiation time and the third local time of each of the corresponding common nodes in the cluster network; Determine a third synchronization time difference between each common node and the corresponding cluster head node in the cluster according to each of the second common network establishment initiation times and the second reference network establishment initiation times; The third local time of each common node is adjusted based on each third synchronization time difference to synchronize with the corresponding cluster head node in the cluster.

7. The method for adaptive time synchronization of a multi-cluster ad hoc network according to claim 2, characterized in that: The intra-cluster head node that does not require intra-cluster networking performs time synchronization with the inter-cluster head node, including: Acquire a first reference network establishment initiation time of the inter-cluster cluster head node, and a third reference network establishment initiation time and a fourth local time of the intra-cluster cluster head node that does not require intra-cluster networking; Determine, according to the first reference network establishment initiation time and the third reference network establishment initiation time, a fourth synchronization time difference between the cluster head node within the cluster that does not require intra-cluster networking and the cluster head node between clusters; The fourth local time of the cluster head node within the cluster that does not require intra-cluster networking is adjusted based on the fourth synchronization time difference to be synchronized to the inter-cluster cluster head node.

8. The method for adaptive time synchronization of a multi-cluster ad hoc network according to claim 1, characterized in that: The method of initializing the time slot structure of each node in the multi-cluster ad hoc network includes: Determining the node status of each initial node in the multi-cluster ad hoc network; If the node state indicates that the initial node is the inter-cluster head node, adjusting the time slot structure of the inter-cluster head node to the first time slot sequence; If the node state indicates that the initial node is a cluster head node in the cluster, adjusting the time slot structure of the cluster head node in the cluster to the second time slot sequence; If the node status indicates that the initial node is a common node that has not joined the network, the time slot structure of the common node is adjusted to the third time slot sequence.

9. The method for adaptive time synchronization of a multi-cluster ad hoc network according to claim 8, characterized in that: After determining the node status of each initial node in the multi-cluster ad hoc network, the method further includes: If the node status indicates that the initial node is the cluster head node in the cluster that does not require intra-cluster networking, the time slot structure of the cluster head node in the cluster that does not require intra-cluster networking is adjusted to a fourth time slot sequence, and the fourth time slot sequence includes inter-cluster time slots.

10. A multi-cluster ad hoc network, characterized in that: The multi-cluster ad hoc network is used to implement the adaptive time synchronization method for the multi-cluster ad hoc network as claimed in any one of claims 1 to 9.

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