Adaptive time synchronization method for multi-cluster ad hoc network and multi-cluster ad hoc network

Abstract

The application discloses a kind of multi-cluster self-organizing network's adaptive time synchronization method and multi-cluster self-organizing network, method includes: initialization time slot structure;Inter-cluster cluster head node uses first time slot sequence, cluster head node in cluster uses second time slot sequence, the ordinary node of un-networked adjustment third time slot sequence;The ordinary node of the network in the cluster where inter-cluster cluster head node is located carries out time synchronization to inter-cluster cluster head node after adjustment first time slot sequence;The ordinary node of remaining network in cluster carries out time synchronization to corresponding cluster head node in cluster after adjustment second time slot sequence;Cluster head node in network time synchronization has completed in cluster determines node total number, first local time and with the first synchronization time difference of inter-cluster cluster head node to generate whole network time synchronization signaling message, so that the first time slot sequence of all nodes in the cluster network is adjusted to inter-cluster cluster head node in same time point time synchronization after adjustment.The application can guarantee the stability of each cluster networking while completing whole network time synchronization.

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 based on 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 communications within the intra-cluster network and, together with the cluster head nodes of other intra-cluster networks, forms an inter-cluster network, also called an inter-cluster node. In the inter-cluster network, there is also an inter-cluster head node, whose function is to initiate and manage communications within the inter-cluster network. The inter-cluster network and each intra-cluster network occupy different frequency bands for communication.

[0003] In multi-cluster ad hoc networks, the cluster head node is typically used as the time reference station. Ordinary nodes within an intra-cluster network synchronize their time with the cluster head node of that cluster to achieve intra-cluster networking. Similarly, ordinary nodes in an inter-cluster network also need to synchronize their time with the inter-cluster head node to achieve inter-cluster networking. However, networking initiation times for different clusters often differ. The cluster head node is a member of both the inter-cluster network and the intra-cluster network. If both the intra-cluster and inter-cluster networks coexist, the cluster head node's local time will conflict. If the cluster head node chooses to synchronize its time directly with either the intra-cluster or inter-cluster network, the stability of the other network will be affected, and the node may be disconnected due to time synchronization discrepancies. The communication time slots of nodes within the intra-cluster network and the inter-cluster network are typically time-divided. If time synchronization is not yet complete, the intra-cluster and inter-cluster communication time slots of different nodes in the same cluster may be completely offset, resulting in a failure of 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 ad hoc networks, which can solve the time discrepancy problem between different clusters, achieve full network time synchronization, and ensure the stability of each cluster 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] The adaptive time synchronization method of the multi-cluster ad hoc network according to the first aspect of the embodiment of the present application, the multi-cluster ad hoc network comprises a plurality of intra-cluster networks and an inter-cluster network, each of the intra-cluster networks comprises an intra-cluster cluster head node, the inter-cluster network comprises 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 comprises the following steps:

[0007] initializing a time slot structure of each node in the multi-cluster ad hoc network; wherein the inter-cluster cluster head node adopts a first time slot sequence, each intra-cluster cluster head node adopts a second time slot sequence, and each ordinary node in the intra-cluster network which has not been networked adopts a third time slot sequence; the first time slot sequence and the second time slot sequence both comprise inter-cluster time slots and intra-cluster time slots which are alternately performed in equal periods, and the period of the inter-cluster time slots and the intra-cluster time slots in the second time slot sequence is at least twice the period of the inter-cluster time slots and the intra-cluster time slots in the first time slot sequence, and the third time slot sequence comprises intra-cluster time slots;

[0008] the ordinary nodes of the intra-cluster network in which the inter-cluster cluster head node is located perform time synchronization to the inter-cluster cluster head node, and adjust the time slot structure to the first time slot sequence after the synchronization is completed;

[0009] the ordinary nodes of the remaining intra-cluster networks perform time synchronization to the corresponding intra-cluster cluster head nodes, and adjust the time slot structure to the second time slot sequence after the synchronization is completed;

[0010] the intra-cluster cluster head node which has completed the intra-cluster network time synchronization determines the total number of nodes of the intra-cluster network, a first local time and a first synchronization time difference with the inter-cluster cluster head node, generates a whole-network time synchronization signaling message and sends the message to each ordinary node of the intra-cluster network, so that all the nodes of the intra-cluster network perform time synchronization to 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.

[0011] The adaptive time synchronization method of the multi-cluster ad hoc network according to the embodiment of the present application has at least the following beneficial effects:

[0012] In order to avoid the inability to complete time synchronization due to the complete mismatch of the intra-cluster and inter-cluster communication time slots 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 inter-cluster cluster head node adopts the first time slot sequence, the intra-cluster cluster head node adopts the second time slot sequence, and the ordinary nodes not connected to the network in each intra-cluster network adopt the third time slot sequence. Then, each intra-cluster network is first synchronized, and after the synchronization is completed, the time slot structure is adaptively adjusted to be the same as the intra-cluster cluster head node. Then, each intra-cluster cluster head node generates a full-network time synchronization signaling message and sends it to each ordinary node in the corresponding 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. This can solve the time difference problem of different clusters and ensure the stability of each cluster network while completing the full-network time synchronization.

[0013] According to 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 require intra-cluster networking adopts a fourth time slot sequence, and the fourth time slot sequence includes inter-cluster time slots;

[0014] The method further comprises:

[0015] 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 synchronization is completed.

[0016] According to some embodiments of the present invention, the network-wide time synchronization signaling message is obtained by the following steps:

[0017] Determine a synchronization initiation time according to the total number of nodes and the first local time;

[0018] The network-wide time synchronization signaling message is generated according to the synchronization initiation time and the first synchronization time difference.

[0019] According to some embodiments of the present invention, the first synchronization time difference is obtained by the following steps:

[0020] Acquire the first local time and the reference time of the cluster head node between clusters;

[0021] The first synchronization time difference is determined according to the first local time and the reference time.

[0022] According to some embodiments of the present invention, performing time synchronization on a common node in the intra-cluster network where the inter-cluster cluster head node is located with respect to the inter-cluster cluster head node includes:

[0023] Acquire a first benchmark 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 in the intra-cluster network where the inter-cluster cluster head node is located;

[0024] Determine a second synchronization time difference between each common node and the inter-cluster head node according to each of the first common network establishment initiation times and the first reference network establishment initiation time;

[0025] 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.

[0026] According to some embodiments of the present invention, the remaining common nodes in each intra-cluster network perform time synchronization with the corresponding intra-cluster head node, including:

[0027] Acquire the second benchmark network establishment initiation time of each of the cluster head nodes in the remaining intra-cluster networks, and the second common network establishment initiation time and third local time of each of the corresponding common nodes in the intra-cluster networks;

[0028] Determining a third synchronization time difference between each common node and the corresponding cluster head node in the cluster according to each second common network establishment initiation time and the second reference network establishment initiation time;

[0029] 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.

[0030] 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:

[0031] 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;

[0032] 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 intra-cluster head node and the inter-cluster head node that do not require intra-cluster networking;

[0033] The fourth local time of the intra-cluster head node that does not require intra-cluster networking is adjusted based on the fourth synchronization time difference to synchronize with the inter-cluster head node.

[0034] 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:

[0035] Determining the node status of each initial node in the multi-cluster ad hoc network;

[0036] 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;

[0037] If the node state indicates that the initial node is the 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;

[0038] 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.

[0039] 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:

[0040] 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, wherein the fourth time slot sequence includes inter-cluster time slots.

[0041] According to a second embodiment of the present invention, the multi-cluster ad hoc network is configured to implement the adaptive time synchronization method for a multi-cluster ad hoc network as described in the first embodiment. Because the multi-cluster ad hoc network employs all of the technical solutions of the adaptive time synchronization method for a multi-cluster ad hoc network described in the above embodiment, it at least has all of the beneficial effects provided by the technical solutions of the above embodiment.

[0042] A control device according to a third embodiment of the present invention includes a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, it implements some of the steps of the adaptive time synchronization method for a multi-cluster ad hoc network described in the first embodiment. Because the control device utilizes all of the technical solutions of the adaptive time synchronization method for a multi-cluster ad hoc network described in the above embodiment, it at least has all the beneficial effects provided by the technical solutions of the above embodiment.

[0043] According to a fourth embodiment of the present invention, a computer-readable storage medium stores computer-executable instructions for executing some of the steps of the adaptive time synchronization method for a multi-cluster ad hoc network as described in the first embodiment. Because the computer-readable storage medium employs all of the technical solutions of the adaptive time synchronization method for a multi-cluster ad hoc network described in the above embodiment, it at least has all of the beneficial effects provided by the technical solutions of the above embodiment.

[0044] 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

[0045] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the following description of the embodiments with reference to the accompanying drawings, in which:

[0046] Figure 1 is a schematic diagram of a multi-cluster ad hoc network according to an embodiment of the present invention;

[0047] Figure 2 is a schematic diagram of a time slot structure according to an embodiment of the present invention;

[0048] Figure 3 The figure is a flow chart of a method for adaptive time synchronization in a multi-cluster ad hoc network according to an embodiment of the present invention. DETAILED DESCRIPTION

[0049] The following describes embodiments of the present invention in detail. Examples of the embodiments 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 intended only to explain the present invention and are not to be construed as limiting the present invention.

[0050] 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.

[0051] In the description of the present invention, it should be understood that descriptions involving orientation, such as the orientation or positional relationship indicated by up, down, etc., are based on the orientation or positional relationship shown in the accompanying 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 cannot be understood as a limitation on the present invention.

[0052] In the description of the present invention, it should be noted that, unless otherwise clearly defined, terms such as setting, installing, and connecting 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 based on the specific content of the technical solution.

[0053] 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, not all of the embodiments.

[0054] 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 figure is a flow chart of a method for adaptive time synchronization in a multi-cluster ad hoc network according to an embodiment of the present invention.

[0055] According to an adaptive time synchronization method for a multi-cluster self-organizing network according to an embodiment of a first aspect of the present invention, the multi-cluster self-organizing network includes multiple intra-cluster networks and one inter-cluster network, each intra-cluster network 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 intra-cluster cluster head nodes, and the inter-cluster cluster head node is a time reference station. The method includes:

[0056] Initializing the time slot structure of each node in the multi-cluster ad hoc network; wherein the inter-cluster head nodes use a first time slot sequence, the intra-cluster head nodes use a second time slot sequence, and the ordinary nodes not connected to the network in each cluster use a 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 alternating 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;

[0057] 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;

[0058] The remaining common nodes in each cluster network perform time synchronization with the corresponding cluster head node, and adjust the time slot structure to the second time slot sequence after synchronization is completed;

[0059] 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.

[0060] 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 require intra-cluster networking adopts a fourth time slot sequence, and the fourth time slot sequence includes inter-cluster time slots;

[0061] The method also includes:

[0062] The cluster head node within the cluster that does not require intra-cluster networking performs time synchronization with the inter-cluster head node, and adjusts the time slot structure to the first time slot sequence after the synchronization is completed.

[0063] In some embodiments of the present invention, initializing the time slot structure of each node in a multi-cluster ad hoc network includes:

[0064] Determine the node status of each initial node in the multi-cluster ad hoc network;

[0065] If the node state indicates that the initial node is the inter-cluster head node, then the time slot structure of the inter-cluster head node is adjusted to the first time slot sequence;

[0066] If the node state indicates that the initial node is the cluster head node in the cluster, then the time slot structure of the cluster head node in the cluster is adjusted to the second time slot sequence;

[0067] 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;

[0068] 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.

[0069] 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:

[0070] (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 inter-cluster head node uses sequence 1, and other nodes also use sequence 1 after synchronizing with the inter-cluster head node to ensure the consistency of the time slot structure.

[0071] (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 between them. Its period length is at least twice that of sequence 1, and 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, and 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;

[0072] (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, thereby completing 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, reducing unnecessary communication time slots and using sequence 1.

[0073] (4) Sequence 4 (i.e. the third time slot sequence) is entirely composed of intra-cluster time slots, and is applicable to nodes that only communicate in the intra-cluster network. The nodes receive the intra-cluster time synchronization signal, thereby completing intra-cluster time synchronization. When the cluster head node in the intra-cluster network is at the inter-cluster communication frequency, the node can stop communication and use sequence 2. Finally, inter-cluster time synchronization is completed (the reason is the same as that of sequence 2 synchronization to sequence 1).

[0074] After all nodes complete time synchronization, sequence 1 is used. The purpose is to ensure that the network communication transmission, frequency, rate, and other configurations are all aligned and consistent, reduce unnecessary time slot configurations, rationally allocate time slot resources, and ensure stable network communication.

[0075] Reference Figure 1 The multi-cluster self-organizing network has three intra-cluster networks and one inter-cluster network. The three intra-cluster networks are represented by sets , set , and set . The inter-cluster network is represented by set . Among them, nodes , , are intra-cluster cluster head nodes, and node is an inter-cluster cluster head node. The remaining nodes are ordinary nodes. In addition, node is an intra-cluster cluster head node that does not need intra-cluster networking. The time reference station of the entire network is the inter-cluster cluster head node . Finally, all nodes need to synchronize to the time of the inter-cluster cluster head node .

[0076] In the initial stage of the multi-cluster self-organizing network building phase, each intra-cluster network first synchronizes to the time of its intra-cluster cluster head node, i.e. node synchronizes to node , node synchronizes to node , and node does not need the intra-cluster synchronization process and is considered to have completed intra-cluster network synchronization.

[0077] In some embodiments of the present application, the ordinary nodes of the intra-cluster network in which the inter-cluster cluster head node is located synchronize to the time of the inter-cluster cluster head node, including:

[0078] obtaining a first reference network building initiation time of the inter-cluster cluster head node, and a first ordinary network building initiation time and a second local time of each ordinary node of the intra-cluster network in which the inter-cluster cluster head node is located;

[0079] determining a second synchronization time difference between each ordinary node and the inter-cluster cluster head node according to each first ordinary network building initiation time and the first reference network building initiation time;

[0080] 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.

[0081] In the collection In the initial network construction phase, the cluster head node in the cluster Considered to have completed 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 slot and intra-cluster slot is T ; The operation cycle within the cluster in sequence 1 is 2 T , the length is T , the cluster operation cycle 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 、 Synchronize to node After completing time synchronization, the node Switch to using sequence 1.

[0082] In some embodiments of the present invention, the remaining common nodes in each intra-cluster network perform time synchronization with the corresponding intra-cluster head node, including:

[0083] Obtaining the second benchmark network establishment initiation time of each cluster head node in each remaining intra-cluster network, and the second common network establishment initiation time and third local time of each corresponding common node in the intra-cluster network;

[0084] Determining 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;

[0085] 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.

[0086] In the collection In the initial network construction phase, the cluster head node in the cluster Considered to be 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 slot and intra-cluster slot is T ; The cluster operation cycle 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 Synchronize to node After completing time synchronization, the node Switch to using sequence 2.

[0087] In some embodiments of the present invention, the intra-cluster head node that does not require intra-cluster networking performs time synchronization with the inter-cluster head node, including:

[0088] Acquire a first benchmark network establishment initiation time of an inter-cluster cluster head node, and a third benchmark network establishment initiation time and a fourth local time of an intra-cluster cluster head node that does not require intra-cluster networking;

[0089] Determine a fourth synchronization time difference between an intra-cluster head node and an inter-cluster head node that do not require intra-cluster networking according to the first reference network establishment initiation time and the third reference network establishment initiation time;

[0090] 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.

[0091] 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 In the inter-cluster networking time slot, time to + TThe cluster inter-networking time slot must be included in the node , and the node must run the cluster inter-networking time slot once within the time period of to +2 T , so that the node , can obtain the synchronization time difference of networking , . At this time, the node can complete time synchronization with the node , and switch to using sequence 1, but the node cannot directly synchronize time with the node , otherwise it will cause the ordinary nodes in the set to drop offline.

[0092] The set , has completed time synchronization, and only the set needs to synchronize time to the node .

[0093] In some embodiments of the application, the network-wide time synchronization signaling message is obtained by the following steps:

[0094] Determine the synchronization initiation time according to the total number of nodes and the first local time;

[0095] Generate a network-wide time synchronization signaling message according to the synchronization initiation time and the first synchronization time difference.

[0096] In some embodiments of the application, the first synchronization time difference is obtained by the following steps:

[0097] Obtain the first local time and the reference time of the cluster inter-cluster head node;

[0098] Determine the first synchronization time difference according to the first local time and the reference time.

[0099] In some embodiments, the local time of the node , is +2 T , the synchronization time difference is , and the synchronization initiation time is +4 T . The node sends a network-wide time synchronization signaling message to , and adjusts the time difference at the synchronization initiation time of +4 T , so that the time of each node in the set is consistent and synchronized to , thus avoiding abnormal node disconnection.

[0100] 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 entire network has completed time synchronization.

[0101] 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 mismatch 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 inter-cluster cluster head node adopts the first time slot sequence, the intra-cluster cluster head node 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 first enables each intra-cluster network to complete time synchronization, and after the synchronization is completed, the time slot structure is adaptively adjusted to be the same as the intra-cluster cluster head node, and then the intra-cluster cluster head node generates a full-network time synchronization signaling message and sends it to each ordinary node of the corresponding 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, 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.

[0102] According to a second embodiment of the present invention, the multi-cluster ad hoc network is used to implement the adaptive time synchronization method for the multi-cluster ad hoc network described in the first embodiment. Because the multi-cluster ad hoc network employs all the technical solutions of the adaptive time synchronization method for the multi-cluster ad hoc network described in the above embodiment, it at least has all the beneficial effects brought about by the technical solutions of the above embodiment.

[0103] 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.

[0104] 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 arranged 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.

[0105] The non-transient software programs and instructions required to implement some steps of the adaptive time synchronization method for multi-cluster self-organizing networks in the above embodiment are stored in the memory. When executed by the processor, some steps of the adaptive time synchronization method for multi-cluster self-organizing networks in the above embodiment are executed.

[0106] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate, i.e., they may be located in one place or distributed across multiple network units. Some or all of the modules may be selected based on actual needs to achieve the objectives of this embodiment.

[0107] In addition, an embodiment of the present invention also provides a computer-readable storage medium, which stores computer-executable instructions. The computer-executable instructions are executed by a processor or controller, for example, by the processor of the above embodiment, so that the above processor can execute some steps in the adaptive time synchronization method of the multi-cluster self-organizing network in the above embodiment.

[0108] Those skilled in the art will appreciate that all or some of the steps and systems disclosed above can be implemented as software, firmware, hardware, or any suitable combination thereof. Some or all of the physical components may be implemented as software executed by a processor, such as a central processing unit, digital signal processor, or microprocessor, or as hardware, or as an integrated circuit, such as an application-specific integrated circuit. Such software may be distributed on computer-readable media, which may include computer storage media (or non-transitory media) and communication media (or transient media). As is well known to those skilled in the art, the term computer storage media 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 includes, but is not limited to, RAM, ROM, EEPROM, flash memory or other memory technologies, CD-ROM, digital versatile disks (DVDs) or other optical disk storage, magnetic cassettes, magnetic tape, magnetic disk storage or other magnetic storage devices, or any other medium that can be used to store the desired information and can be accessed by a computer. Furthermore, as is well known to those skilled in the art, 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.

[0109] The embodiments of the present invention are described in detail above with reference to the accompanying drawings, but the present invention is not limited to the above embodiments. Various changes can be made within the scope of knowledge possessed by ordinary technicians in the relevant technical field without departing from the scope of the present invention.

Claims

1. An adaptive time synchronization method for a multi-cluster ad hoc network, wherein the multi-cluster ad hoc network comprises multiple intra-cluster networks and one inter-cluster network, each intra-cluster network comprises an intra-cluster head node, the inter-cluster network comprises 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: Initializing the time slot structure of each node in a multi-cluster ad hoc network; wherein the inter-cluster cluster head nodes use a first time slot sequence, the intra-cluster cluster head nodes use a second time slot sequence, and ordinary nodes not connected to the network in each cluster use a 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 alternating 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 in 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 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.

2. The adaptive time synchronization method for 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 synchronization is completed.

3. The adaptive time synchronization method for a multi-cluster ad hoc network according to claim 1, wherein: 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 network-wide time synchronization signaling message is generated according to the synchronization initiation time and the first synchronization time difference.

4. The adaptive time synchronization method for 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 clusters; The first synchronization time difference is determined according to the first local time and the reference time.

5. The adaptive time synchronization method for 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 benchmark 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 in 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 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 adaptive time synchronization method for 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 benchmark network establishment initiation time of each of the cluster head nodes in the remaining intra-cluster networks, and the second common network establishment initiation time and third local time of each of the corresponding common nodes in the intra-cluster networks; Determining a third synchronization time difference between each common node and the 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 synchronize with the corresponding cluster head node in the cluster.

7. The adaptive time synchronization method for 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 intra-cluster head node and the inter-cluster head node that do not require intra-cluster networking; The fourth local time of the intra-cluster head node that does not require intra-cluster networking is adjusted based on the fourth synchronization time difference to synchronize with the inter-cluster head node.

8. The adaptive time synchronization method for 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 the 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 adaptive time synchronization method for 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, wherein 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 a multi-cluster ad hoc network as claimed in any one of claims 1 to 9.

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