Node synchronization method for wireless ad hoc network, master node and relay slave node

Abstract

The invention discloses a node synchronization method for a wireless ad hoc network, a master node and a relay slave node. The wireless ad hoc network comprises a master node and at least one relay slave node, and the node synchronization method comprises the following steps: the master node sends a frame synchronization signal and a broadcast message; the relay slave node obtains frame synchronization between the relay slave node and the master node sending the frame synchronization signal or other relay slave nodes based on the received frame synchronization signal, and after frame synchronization is obtained, the relay slave node sends the frame synchronization signal so that other nodes can obtain frame synchronization with the relay slave node by receiving the frame synchronization signal sent by the relay slave node; channels used by frame synchronization channels for sending the frame synchronization signals by the master node and the relay slave node are changed based on a system frequency hopping sequence. According to the method disclosed by the invention, a communication node synchronization network with a tree structure can be formed, the anti-interference capability of the communication nodes is improved, and signal interference between the communication nodes is avoided.

Description

Technical Field

[0001] The present application relates to the field of wireless communication technology, and in particular, to a node synchronization method, a master node, and a relay slave node for a wireless ad hoc network. Background Art

[0002] A wireless ad hoc network is a network composed of multiple communication nodes that does not require pre-deployment and has great flexibility. Each communication node of a wireless ad hoc network needs to be self-organized to form a communication network. Therefore, how to efficiently achieve synchronization between communication nodes is a key step in deploying a wireless ad hoc network.

[0003] In addition, wireless ad hoc networks often operate in unlicensed frequency bands, and the use of unlicensed frequency bands does not require a license. There are many communication protocols such as WiFi and Bluetooth that stipulate the use of unlicensed frequency bands as communication frequency bands. Therefore, the communication nodes of wireless ad hoc networks are easily affected by interference from other devices, making the wireless environment of wireless ad hoc networks relatively uncontrollable. In addition, due to the different geographical locations of each communication node in the wireless ad hoc network, the interference conditions of each communication node are also different, and the wireless environment is quite different. Since the resources of unlicensed frequency bands are limited, the frequency resources need to be coordinated between the communication nodes within the wireless ad hoc network to avoid mutual interference between the communication nodes in the wireless ad hoc network. Summary of the invention

[0004] One object of the present application is to provide a node synchronization method, a master node and a slave node for wireless ad hoc network, so as to efficiently achieve synchronization between communication nodes. Another object of the present application is to improve the anti-interference ability of the node and avoid mutual interference between nodes in the wireless ad hoc network.

[0005] One aspect of the present application provides a node synchronization method for a wireless self-organizing network, wherein the wireless self-organizing network includes multiple nodes, and the multiple nodes include a master node and at least one relay slave node. The method includes: the master node sends a frame synchronization signal; the relay slave node obtains frame synchronization between itself and the master node or other relay slave nodes that sends the received frame synchronization signal based on the received frame synchronization signal sent by the master node or other relay slave nodes; after the relay slave node obtains frame synchronization between itself and the master node or other relay slave nodes that sends the received frame synchronization signal, it sends a frame synchronization signal so that other nodes can obtain frame synchronization with the relay slave node that sends the frame synchronization signal by receiving the frame synchronization signal sent by the relay slave node; the frequency channels used by the frame synchronization channels used by the master node and the relay slave node for sending frame synchronization signals change based on the system frequency hopping sequence.

[0006] In some embodiments, the master node sending a frame synchronization signal includes: the master node sending the frame synchronization signal on at least one frame synchronization channel included in the frame, the relay slave node obtains frame synchronization between itself and the master node or other relay slave nodes that send the received frame synchronization signal based on the received frame synchronization signal sent by the master node or other relay slave nodes, and sending the frame synchronization signal includes: the relay slave node receives and tracks the frame synchronization signal sent by the master node or other relay slave node on one of at least two frame synchronization channels included in the frame, and sends the frame synchronization signal on at least one frame synchronization channel of the at least two frame synchronization channels that is not used to receive and track the frame synchronization signal.

[0007] In some embodiments, the frequency channels used by the frame synchronization channels used by the master node and the relay slave node for sending frame synchronization signals cyclically change based on a system frequency hopping sequence.

[0008] In some embodiments, the frequency channels used by the frame synchronization channels of the master node and the relay slave node for sending frame synchronization signals are changed at fixed time intervals based on a system frequency hopping sequence, and the fixed time intervals take frames as time units.

[0009] In this embodiment, the frequency channels used by the frame synchronization channels used by the master node and the relay slave node for sending frame synchronization signals are changed based on system frequency hopping sequences of the same length.

[0010] In some embodiments, each frame synchronization channel used to send a frame synchronization signal is associated with a frequency hopping offset, where the frequency hopping offset is an offset of a frequency channel sequence used by the frame synchronization channel relative to a frequency channel sequence used by a designated frame synchronization channel of a reference node.

[0011] In this embodiment, the frequency channels used by the frame synchronization channels used by the master node and the relay slave node for sending frame synchronization signals respectively change based on the system frequency hopping sequence, including: the relay slave node determines the frequency channel used by its frame synchronization channel for sending frame synchronization signals based on the system frequency hopping sequence, the frequency channel on which its received frame synchronization signal is located, and the difference between the frequency hopping offset associated with the frame synchronization channel used to send the received frame synchronization signal and the frequency hopping offset associated with the frame synchronization channel used to send the frame synchronization signal.

[0012] In this embodiment, the node synchronization method of the wireless self-organizing network also includes: the master node sends a broadcast message, the broadcast message includes the frequency hopping offset associated with the frame synchronization channel used by the master node and / or the relay slave node in the wireless self-organizing network to send frame synchronization signals; the relay slave node obtains through the broadcast message it receives the difference between the frequency hopping offset associated with the frame synchronization channel used by the node sending the broadcast message to send frame synchronization signals and the frequency hopping offset associated with the frame synchronization channel used by the relay slave node to send frame synchronization signals.

[0013] In this embodiment, the master node and the relay slave node send the frequency hopping offset associated with the frame synchronization channel used by the master node and the relay slave node to send frame synchronization signals in the wireless self-organizing network through a global broadcast method. The method includes: the relay slave node obtains the frequency hopping offset associated with the frame synchronization channel used by the master node and / or the relay slave node to send frame synchronization signals in the wireless self-organizing network by receiving broadcast messages from the master node or other relay slave nodes.

[0014] In some embodiments, the master node and / or the relay slave node sends a frame synchronization signal and a broadcast message within one broadcast time slot.

[0015] In some embodiments, the method further includes: the master node and / or the relay slave node sends a broadcast message, the broadcast message includes the system frequency hopping sequence, and the relay slave node obtains the system frequency hopping sequence by receiving the broadcast message sent by the master node or other relay slave nodes.

[0016] In some embodiments, the method also includes: the master node and / or the relay slave node sends a broadcast message, which includes configuration information of the frame synchronization relationship between nodes in the wireless self-organizing network, and the relay slave node obtains the parent node assigned to the relay slave node receiving the broadcast message by receiving the broadcast message sent by the master node or other relay slave nodes, and then obtains frame synchronization with its parent node by receiving the frame synchronization signal sent by its parent node.

[0017] In some embodiments, the master node sends a frame synchronization signal on at least two frame synchronization channels included in one frame thereof.

[0018] According to a second aspect of the present disclosure, a method for node synchronization of a wireless ad hoc network is provided, wherein the wireless ad hoc network comprises a plurality of nodes, wherein the plurality of nodes include a master node and at least one relay slave node, and the method is applied to the master node, and the method comprises: sending a frame synchronization signal through a frame synchronization channel; wherein a frequency channel used for sending the frame synchronization channel changes based on a system frequency hopping sequence associated with the frame synchronization channel.

[0019] In some embodiments, the frequency channel used by the frame synchronization channel changes at fixed time intervals based on a system frequency hopping sequence, and the fixed time intervals use frames as time units.

[0020] In some embodiments, the frame synchronization channel is transmitted via a broadcast time slot.

[0021] In some embodiments, the method further includes: sending a broadcast message via a frame synchronization channel, wherein the broadcast message includes a frequency hopping offset associated with a frame synchronization channel used by other nodes in the wireless ad hoc network to send frame synchronization signals.

[0022] The third aspect of the present disclosure provides a method for node synchronization in a wireless ad hoc network, wherein the wireless ad hoc network includes multiple nodes, wherein the multiple nodes include a master node and at least one relay slave node, and the method is applied to the relay slave node, and the method includes: receiving a frame synchronization signal sent by the master node or other relay slave nodes, and based on the received frame synchronization signal sent by the master node or other relay slave nodes, obtaining frame synchronization between itself and the master node or other relay slave nodes that sent the received frame synchronization signal; after obtaining frame synchronization between itself and the master node or other relay slave nodes that sent the received frame synchronization signal, sending a frame synchronization signal through a frame synchronization channel so that other nodes can obtain frame synchronization with the relay slave node by receiving the frame synchronization signal sent by the relay slave node; wherein the frequency channel used by the frame synchronization channel for sending the frame synchronization signal by the relay slave node changes based on the system frequency hopping sequence associated with the frame synchronization channel.

[0023] In some embodiments, the frequency channel used by the frame synchronization channel for sending the frame synchronization signal by the relay slave node changes at fixed time intervals based on a system frequency hopping sequence, and the fixed time intervals use frames as time units.

[0024] In some embodiments, the frame synchronization channel is transmitted via a broadcast time slot.

[0025] In some embodiments, the frame synchronization channel used by the relay slave node to send frame synchronization signals is associated with a frequency hopping offset, which is an offset of a channel sequence used by the frame synchronization channel relative to a channel sequence used by a designated frame synchronization channel of a reference node.

[0026] The fourth aspect of the present disclosure provides a master node of a wireless ad hoc network, comprising: a channel generation unit, which is configured to generate a channel used for sending broadcast time slots based on a system frequency hopping sequence; a frame synchronization signal generation unit, which is configured to generate a frame synchronization signal; and a signal sending unit, which is configured to send the frame synchronization signal through the frame synchronization channel.

[0027] According to a fifth aspect of the present disclosure, a relay slave node of a wireless ad hoc network is provided, comprising: a receiving channel generating unit, configured to generate a channel for receiving broadcast time slots based on a first system frequency hopping sequence; a sending channel generating unit, configured to generate a channel for sending broadcast time slots based on a second system frequency hopping sequence; a signal receiving unit, configured to receive a frame synchronization signal sent by a master node or other relay slave nodes through a frame synchronization channel; a frame synchronization unit, configured to obtain frame synchronization between itself and the master node or other relay slave nodes that sends the received frame synchronization signal based on the received frame synchronization signal sent by the master node or other relay slave nodes; a frame synchronization signal generating unit, configured to generate a frame synchronization signal; and a signal sending unit, configured to send the frame synchronization signal through the frame synchronization channel after obtaining frame synchronization between itself and the master node or other relay slave nodes that sends the received frame synchronization signal.

[0028] In a sixth aspect of the present disclosure, a master node of a wireless ad hoc network is provided, comprising a processor and a non-volatile storage medium storing computer executable instructions, wherein the computer executable instructions can be executed by the processor to execute the steps and functions performed by the master node in each embodiment of the above method.

[0029] According to a seventh aspect of the present disclosure, a relay slave node of a wireless ad hoc network is provided, comprising a processor and a non-transitory storage medium storing computer-executable instructions, wherein the computer-executable instructions can be executed by the processor to execute the steps and functions performed by the relay slave node in various embodiments of the method.

[0030] The above is an overview of the present application, which may be simplified, summarized, and omitted in detail. Therefore, those skilled in the art should recognize that this section is only illustrative and is not intended to limit the scope of the present application in any way. This summary section is neither intended to determine the key features or essential features of the claimed subject matter, nor is it intended to be used as an auxiliary means to determine the scope of the claimed subject matter. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] The above and other features of the present application will be more fully understood through the following description and the attached claims in conjunction with the accompanying drawings. It is understood that these drawings only depict several embodiments of the present application and should not be considered as limiting the scope of the present application. By using the accompanying drawings, the present application will be more clearly and detailed.

[0032] Figure 1 A schematic diagram of a wireless ad hoc network disclosed in the present invention is shown;

[0033] Figure 2A frame structure that can be used to implement the node synchronization method for a wireless ad hoc network disclosed in the present invention is shown;

[0034] Figure 3 The configuration mode of the broadcast time slot in the frame structure of each node is exemplarily shown;

[0035] Figure 4 A node synchronization method 100 for a wireless ad hoc network according to an embodiment of the present disclosure is shown;

[0036] Figure 5 A schematic diagram showing an exemplary configuration of a broadcast time slot transmission channel;

[0037] Figure 6 A schematic diagram showing mapping each element of a single system frequency hopping sequence to multiple system frequency hopping sequences is shown;

[0038] Figure 7 A schematic diagram showing the channel allocation results of multiple system frequency hopping sequences;

[0039] Figure 8 A structural block diagram of a master node 300 of a wireless ad hoc network according to an embodiment of the present disclosure is shown;

[0040] Fig. 9 A structural block diagram of a relay slave node 400 of a wireless ad hoc network according to an embodiment of the present disclosure is shown;

[0041] Fig.10 A structural block diagram of a master node 500 of a wireless ad hoc network according to an embodiment of the present disclosure is shown;

[0042] Fig.11 A structural block diagram of a relay node 600 of a wireless ad hoc network according to an embodiment of the present disclosure is shown. DETAILED DESCRIPTION

[0043] In order to make the purpose, technical solutions and advantages of the present disclosure clearer, the present disclosure will be described in detail below in conjunction with the accompanying drawings. In the accompanying drawings, similar symbols generally represent similar components unless the context otherwise indicates. The illustrative embodiments described in the detailed description, drawings and claims are not intended to be limiting. Other embodiments may be adopted and other changes may be made without departing from the spirit or scope of the subject matter of the present application. It is understood that various aspects of the content of the present application generally described in the present application and illustrated in the accompanying drawings may be configured, replaced, combined, and designed in a variety of different configurations, all of which clearly constitute part of the content of the present application.

[0044] To facilitate understanding by those skilled in the art, Figure 1 Schematic diagram of the wireless ad hoc network disclosed in the present invention is shown. Figure 1As shown, the wireless ad hoc network includes multiple communication nodes, and these communication nodes all have wireless transceiver functions. For the sake of simplicity, "communication node" is referred to as "node" in this disclosure. "Node" can be a communication device, or a communication unit or module in a device. Each node in the wireless ad hoc network can be distinguished by a node identifier, that is, in a wireless ad hoc network, each node has a unique node identifier. A node in the wireless ad hoc network can use a suitable channel to send or receive wireless signals in a specified time domain according to the configuration. In this disclosure, a channel represents a frequency interval with a certain bandwidth, and a channel can be represented by a center frequency, or by a pre-compiled channel number. In general, two different channels do not overlap in frequency to avoid mutual interference.

[0045] In the present disclosure, in a wireless ad hoc network, based on whether the node needs to determine the time reference by receiving the frame synchronization signal sent by other nodes in the wireless ad hoc network, the nodes of the wireless ad hoc network can be generally divided into master nodes and slave nodes. The master node can determine the time reference by its own clock, or by receiving the synchronization signal of the external network (for example, the synchronization signal sent by the external network device or other wireless ad hoc network) or the clock signal (for example, the clock sent by the GPS, Beidou satellite system), and periodically sends the frame synchronization signal. The slave node needs to determine the time reference by the frame synchronization signal sent by other nodes in the wireless ad hoc network, and the slave node can be further divided into a relay slave node and a terminal slave node. After the relay slave node is synchronized with the parent node, it also periodically sends a frame synchronization signal for other slave nodes to search. The terminal slave node does not send a frame synchronization signal. A slave node can be configured as a relay state as needed. When the slave node is configured as a relay state, it is a relay slave node, and when it is configured as a non-relay state, it is a terminal slave node. It should be noted that the node in the present disclosure is synchronized with the wireless ad hoc network, which means that the node can determine the system time reference of the wireless ad hoc network. In the present disclosure, the number of master nodes is 1, and the number of slave nodes can be 1 or more. Figure 1 The topology of a wireless ad hoc network is shown as an example, where node 1 is the master node and nodes 2-8 are slave nodes. Figure 1 The topology shown in FIG. Nodes 3, 4, 6, and 8 are configured as relay slave nodes, and nodes 2, 5, and 7 are configured as end slave nodes.

[0046] Figure 1In the figure, an arrow from one node to another node indicates the synchronization relationship between the two nodes. When there is an arrow from node i to node j, it indicates that node j achieves frame synchronization with node i by receiving the frame synchronization signal sent by node i, thereby achieving synchronization with the wireless ad hoc network, and further maintains frame synchronization with node i by further receiving and tracking the frame synchronization signal sent by node i, thereby maintaining synchronization with the wireless ad hoc network. Node i is the parent node of node j, and node j is the child node of node i. Here, i and j are the node numbers. For example Figure 1 In the figure, nodes 2, 3, 6 and 7 are synchronized with the wireless ad hoc network by receiving the frame synchronization signal sent by node 1. Node 1 is the parent node of nodes 2, 3, 6 and 7, and nodes 2, 3, 6 and 7 are the child nodes of node 1. Node 4 is synchronized with the wireless ad hoc network by receiving the frame synchronization signal sent by node 3. Node 3 is the parent node of node 4, and node 4 is the child node of node 3, and so on. It should be pointed out that Figure 1 The wireless ad hoc network topology structure formed by the synchronization relationship of multiple nodes shown is only exemplary, and the method of the present disclosure does not impose any restrictions on the topology structure of the wireless ad hoc network formed by multiple nodes. In the present disclosure, a node A "tracks" a frame synchronization signal sent by another node B, which means that node A receives the frame synchronization signal sent by node B according to a fixed tracking period, thereby maintaining frame synchronization with node B. The tracking period can be 1 frame or several frames, and a balance can be made according to stability and power consumption requirements during specific implementation.

[0047] also, Figure 1 The wireless ad hoc network shown also includes a network control center (not shown in the figure), which is used to control the network locally or globally, for example, to set system parameters (including frame period, frequency hopping sequence, etc.), to allocate physical resources to nodes, etc. It should be understood that in specific implementation, the network control center can be integrated into the node or can be a separate device. It can be implemented in software, hardware, or a combination of hardware and software.

[0048] In the present disclosure, nodes perform actions such as sending and receiving wireless signals based on their frame structures to achieve synchronization of nodes and coordinate communication between nodes. Figure 2 A frame structure that can be used to implement the node synchronization method for wireless ad hoc networks disclosed in the present invention is shown. Figure 2As shown, the wireless physical resources can be divided into multiple frames in terms of time. The start time and end time of the frame define the frame boundary. From the start to the end of the frame is a frame period, and the frame is repeated with the same frame period. The frame period can be a fixed value, but it can also be dynamically configured as needed. For example, the frame period can be switched at an agreed time. Different nodes in the wireless ad hoc network can have different frame structures, but the frame boundaries of each node are aligned with each other in time, so the frame period of each node is the same.

[0049] Each frame of a node may include multiple time slots. Depending on the function of the time slot, the time slots may be divided into different types, such as broadcast time slots (BR) time slots, data time slots, and access time slots. The broadcast time slot carries the frame synchronization channel and the broadcast channel. The frame synchronization channel is used to carry the frame synchronization signal, and the broadcast channel is used to carry the broadcast message. The frame synchronization signal can be used to provide a time reference. The node obtains the time reference and determines the time boundary of the frame by searching for the frame synchronization signal. In addition, considering factors such as the transceiver switching, there may be a certain gap between adjacent time slots (not shown in the figure). Exemplarily, a broadcast message may include one or more information blocks, each of which includes an information type and information content. In order to distinguish between information blocks of the same type contained in different broadcast messages, the information block may also include a sequence number, and different sequence numbers correspond to different information blocks. Different information types may be defined as needed to achieve different functions. The broadcast message may include control information, which is used to control the wireless ad hoc network or node, and the control information may be organized in the form of information blocks.

[0050] Each node performs wireless signal transmission and reception in the time slot assigned to it. The time slot type, number, position, length, channel and other parameters of the node's frame structure can be pre-configured or dynamically configured according to different needs. For the same time interval, different nodes can be assigned different types of time slots. For example, in the corresponding time domains in the frame of the two broadcast time slots BR1 and BR2 of a certain relay slave node, for the master node, it can be configured as the master node's broadcast time slot BR1 and access time slot. The time slot configuration of a node in its frame period is called the frame structure of the node.

[0051] The frame structure of the master node includes at least one broadcast time slot for sending frame synchronization signals and broadcast messages. After the master node is powered on, it can send frame synchronization signals and broadcast messages in its broadcast time slot according to the configuration. In some embodiments, the frame structure of the master node may include only one broadcast time slot for sending frame synchronization signals and broadcast messages. In some embodiments, the frame structure of the master node may include two or more broadcast time slots for sending frame synchronization signals and broadcast messages. Since the number of frame synchronization signals sent within a frame period increases, the probability of the slave node searching for the frame synchronization signal sent by the master node can be increased and the flexibility of the relay slave node sending the frame synchronization signal position is increased.

[0052] The frame structure of the relay slave node contains at least two broadcast time slots, one of which is used to receive frame synchronization signals and broadcast messages sent by the master node or other relay slave nodes, and the other broadcast time slots are used to send frame synchronization signals and broadcast messages. The terminal slave node does not need to send frame synchronization signals and broadcast messages, and its frame structure only contains one broadcast time slot, which is used to receive frame synchronization signals and broadcast messages sent by the master node or relay slave node.

[0053] For the sake of convenience, in the frame structure of each node, the broadcast time slot used to send the frame synchronization signal and the broadcast message is called the sending broadcast time slot, and the broadcast time slot used to receive the frame synchronization signal and the broadcast message is called the receiving broadcast time slot. It can be understood that the sending broadcast time slot in the frame structure of one node can overlap in time with the receiving broadcast time slot in the frame structure of another node.

[0054] Figure 2 The example shows that the node frame structure includes two broadcast time slots, which are represented by BR1 and BR2 respectively. However, it should be pointed out that Figure 2 The frame structure shown is merely exemplary, and the present disclosure does not limit the number of broadcast time slots contained in a frame.

[0055] for Figure 1 The wireless ad hoc network shown, Figure 3 The configuration of the broadcast time slot in the frame structure of each node is exemplarily shown. Figure 3 In the figure, the subscript "TX" indicates that the node transmits (Transmit, TX) signals in the broadcast time slot, and the subscript "RX" indicates that the node receives (Receive, RX) signals. Figure 3In the example shown, BR1 and BR2 in the frame structure of node 1 are both sending time slots; BR1 in the frame structure of node 4 and node 6 is a sending time slot, and BR2 is a receiving time slot; BR1 in the frame structure of node 3 and node 8 is a receiving time slot, and BR2 is a sending time slot; BR1 in the frame structure of node 2 and node 5 is a receiving time slot, and BR2 in the frame structure of node 7 is a receiving time slot. It should be pointed out that although Figure 3 It is shown that the BR1 time slot is located at the starting position of the frame structure of each node, but this is only exemplary. The BR1 time slot can be set to have a certain time offset from the starting position of the frame structure as needed.

[0056] In some implementations, different nodes can set the numbering sequence of the broadcast time slots in their frame structures and the start time of the frames as needed. For example, for node 6, it obtains synchronization by receiving the frame synchronization signal sent by node 1 on BR2. It can set the time slot number in its frame structure to BR1, and use the start time of the time slot as the start of its frame, and set the time slot number corresponding to the BR1 time slot of node 1 to BR2. However, those skilled in the art will understand that this implementation is different from Figure 3 The frame structures shown are only different in form, and the two are essentially the same. For the sake of simplicity, in this disclosure, for the same time interval, broadcast time slots of different nodes are represented by the same number, that is, broadcast time slots of different nodes with the same number correspond to the same time interval.

[0057] The node synchronization method for a wireless ad hoc network according to an embodiment of the present disclosure will be described in detail below with reference to the accompanying drawings.

[0058] Figure 4 A node synchronization method 100 for a wireless ad hoc network according to an embodiment of the present disclosure is shown. However, it should be noted that the drawings of the present disclosure are merely embodiments that can implement the method 100 of the present disclosure, and are not intended to limit the present disclosure. Specifically, the method 100 includes the following steps:

[0059] In step 110, the master node sends a frame synchronization signal and a broadcast message.

[0060] In the present disclosure, the master node may send a frame synchronization signal and a broadcast message respectively in a frame synchronization channel and a broadcast channel of at least one broadcast transmission time slot included in its frame structure according to the configuration.

[0061] In some embodiments, the frame structure of the master node may include only one broadcast time slot for sending a frame synchronization signal and a broadcast message.

[0062] In some embodiments, the master node may use two or more broadcast time slots included in its frame structure to send frame synchronization signals and broadcast messages. Compared with the case where only one broadcast time slot included in the frame structure is used to send a frame synchronization signal, the probability of the slave node searching for the frame synchronization signal sent by the master node can be increased due to the increase in the number of frame synchronization signals sent within a frame period, and the flexibility of the position of the relay slave node sending the frame synchronization signal can be increased.

[0063] In step 120, the slave node maintains frame synchronization with the master node or other relay slave nodes that transmit the frame synchronization signal based on the received frame synchronization signal transmitted by the master node or other relay slave nodes.

[0064] The slave node is in an unsynchronized state before searching for a frame synchronization signal sent by the master node or other relay slave nodes. It searches for the frame synchronization signal, and after searching for the frame synchronization signal, it enters the synchronization state and receives and tracks the frame synchronization signal in a frame synchronization channel of a broadcast time slot contained in the frame to maintain synchronization with the node that sends the frame synchronization signal, that is, its parent node, thereby maintaining synchronization with the wireless ad hoc network. The slave node further receives the broadcast message sent by its parent node in the broadcast channel of the broadcast time slot and obtains control information from the broadcast message.

[0065] In step 130, after receiving the frame synchronization signal and the broadcast message sent by the master node or other relay slave nodes, the relay slave node sends a frame synchronization signal and a broadcast message.

[0066] For the relay slave node, in order to enable other nodes to achieve synchronization with the wireless ad hoc network, after entering the synchronization state, it further sends a frame synchronization signal on the frame synchronization channel of at least one broadcast time slot contained in its frame structure that is not used to receive and track the frame synchronization signal, and sends a broadcast message in the broadcast channel.

[0067] For the end slave node, since it does not send frame synchronization signals and broadcast messages, its frame structure may only include one broadcast time slot for receiving frame synchronization signals and broadcast messages sent by the master node or relay slave node.

[0068] In order to facilitate the understanding of those skilled in the art, Figure 3 The frame structure shown in FIG. 1 is used to exemplarily illustrate the node synchronization method 100 of the present disclosure. Figure 3As shown, node 1 sends frame synchronization signals and broadcast messages in both BR1 and BR2 time slots included in its frame structure; node 2 is an end slave node, which receives signals sent by node 1 in the BR1 time slot included in its frame structure; node 3 is a relay slave node, which receives signals sent by node 1 in the BR1 time slot included in its frame structure, and sends frame synchronization signals and broadcast messages in the BR2 time slot; node 4 is a relay slave node, which receives signals sent by node 3 in the BR2 time slot included in its frame structure, and sends frame synchronization signals and broadcast messages in the BR1 time slot. For the transmission and reception of the remaining nodes, you can combine Figure 1 The topology shown and Figure 3 The frame structure of each node in the relay slave node can be understood, and no further description is given here. It should be noted that the relay slave node sends the frame synchronization signal and broadcast message in its broadcast time slot after synchronizing with the self-organizing network. That is, the relay slave node does not send the frame synchronization signal and broadcast message in its broadcast time slot before synchronizing with the self-organizing network.

[0069] from Figure 3 It can be seen that according to the method disclosed in the present invention, multiple nodes can simultaneously send signals in the broadcast time slot of the same time domain. When there are two sending nodes that are close to each other, a node that receives signals in the broadcast time slot may receive signals from the two sending nodes at the same time. Since the number of channels is limited, if the two nodes use the same channel to send signals, it may cause greater interference, making it difficult for the receiving node to synchronize. In order to solve the above interference problem when sending frame synchronization signals and broadcast messages in a frequency hopping manner, the present invention further proposes a frequency hopping method, which can solve the problem of effectively avoiding interference between signals sent by multiple nodes in the broadcast time slot of the same time domain in a frequency hopping manner when the number of channels is limited.

[0070] According to the frequency hopping method disclosed in the present invention, when the master node and the relay slave node send signals in a broadcast time slot, the frequency channel used by each node changes based on the system frequency hopping sequence associated with the broadcast time slot.

[0071] In the present disclosure, a system frequency hopping sequence refers to a sequence of channel changes associated with a specific time slot of a node of a wireless ad hoc network, and the sequence can be pre-configured for each node, or generated by a network control center and dynamically configured for each node. In some embodiments, within the same time period, the system frequency hopping sequence used by each node of the wireless ad hoc network in the broadcast time slot is unique. In some embodiments, in order to prevent tracking or improve communication confidentiality, within the same time period, each node of the wireless ad hoc network can also use multiple system frequency hopping sequences in the broadcast time slot, and different nodes can be configured with different system frequency hopping sequences in different broadcast time slots. For the sake of convenience, the number of system frequency hopping sequences associated with the broadcast time slot of each node in the wireless ad hoc network can be expressed as K, K≥1, then the kth system frequency hopping sequence can be expressed as the channel sequence f k,0 , f k,1 , …, f k,Nk-1 , where 0≤k≤K-1, N k is the length of the kth system frequency hopping sequence, f k,n (n=0,1,…,N k -1) is the nth element of the kth system frequency hopping sequence. It should be noted that the lengths of the system frequency hopping sequences associated with the broadcast time slots in which the nodes in the wireless ad hoc network send signals may be different. Considering the ease of implementation, when the nodes in the wireless ad hoc network use different system frequency hopping sequences in their respective broadcast time slots, they usually use system frequency hopping sequences of the same length. In the following related examples, two system frequency hopping sequences of the same length are selected for illustration.

[0072] It should be noted that in the present disclosure, the channel used by the node's broadcast time slot changes based on the system frequency hopping sequence associated with the time slot, which means that the channel used by the node to send signals in the broadcast time slot is derived from the system frequency hopping sequence configured for the broadcast time slot of the node.

[0073] In some embodiments, the frequency channel used by the node to send signals in the broadcast time slot changes at fixed time intervals based on the system frequency hopping sequence. The fixed time interval uses frames as time units, that is, the fixed time interval is an integer multiple of the frame period.

[0074] In some embodiments, the channel sequence used by a node to send a signal in a broadcast time slot in its frame structure in a frequency hopping manner changes cyclically according to a fixed channel sequence period, and the channel sequence within a channel sequence period is a cyclic shift of the system frequency hopping sequence associated with the broadcast time slot. To facilitate understanding by those skilled in the art, the following is explained by an example. Assume that the system frequency hopping sequence associated with a broadcast time slot for sending a signal in the frame structure of the node is It uses channel f in the broadcast time slot of the nth frame k,n1, the channel used in the broadcast time slot changes at a fixed time interval of 2 frames, then the channel used in the broadcast time slot in the (n+2)th frame is The channel used by the broadcast time slot in the (n+2m)th frame is Among them, 0≤n1≤N k -1, m is a positive integer, "mod" means modulo operation, for a mod b (where a and b are both positive integers), the result is the remainder of a divided by b. The channel sequence used by the node to send a signal in a broadcast time slot in its frame structure obtained by the above method is a cyclic sequence.

[0075] In order to avoid conflicts caused by different nodes using the same channel to send signals in the same time domain, each broadcast time slot for sending signals of each node is associated with a frequency hopping offset, which indicates the offset of the channel sequence used by the node when sending signals in the broadcast time slot relative to the channel sequence used by the designated broadcast time slot of the reference node. The designated broadcast time slot is a broadcast time slot in the frame structure of the reference node, which can be pre-configured for each node of the wireless ad hoc network, or adjusted by the control center as needed.

[0076] It should be noted that the length of the system frequency hopping sequence associated with the broadcast time slot for sending signals of a node should be the same as the length of the system frequency hopping sequence associated with the designated broadcast time slot of the reference node corresponding to the frequency hopping offset associated with the broadcast time slot. Even if the same system frequency hopping sequence is used in a wireless ad hoc network, by setting different frequency hopping offsets for the broadcast time slots for sending signals of different nodes, when different nodes send signals in the broadcast time slots in the same time domain, the channels for sending signals of different nodes are different, so the signal interference between nodes can be effectively avoided. The wireless ad hoc network can select the corresponding node as the reference node as needed, so the reference node can be the master node or a slave node. It should also be noted that since the frame synchronization channel and the broadcast channel are carried by the broadcast time slot, it can also be considered that each frame synchronization channel for sending frame synchronization signals of each node is each associated with a frequency hopping offset. Therefore, the method of applying the frequency hopping offset to the broadcast time slot to derive the channel sequence used by the broadcast time slot in the present disclosure can be applied to the frame synchronization channel.

[0077] Since the channel sequence used by the reference node's designated broadcast time slot is a reference for other nodes to determine the channel sequence used to send signals in their broadcast time slots based on their frequency hopping offsets, the reference node's designated broadcast time slot may have no frequency hopping offset, or its frequency hopping offset may be set to 0 by default.

[0078] Since the relative value of the frequency hopping offset of each node obtained by selecting different nodes as the reference node does not change, there is no substantial difference in which node is selected as the reference node. Considering the ease of implementation, the main node is usually used as the reference node. Therefore, in the following text, unless otherwise specified, the main node is used as the reference node.

[0079] In some embodiments, in order to simplify the system implementation, only the same system frequency hopping sequence or multiple system frequency hopping sequences of the same length are used in the wireless ad hoc network. At this time, if the master node is a reference node, the first broadcast time slot of the master node is a designated broadcast time slot. For the master node, if it uses two or more broadcast time slots to send signals in a frame period, each broadcast time slot may also be associated with a frequency hopping offset, which indicates the offset of the channel sequence used by the master node when sending signals in the broadcast time slot relative to the channel sequence used in the first broadcast time slot of the master node. At this time, the frequency hopping offset associated with the transmission broadcast time slot of the slave node is the offset of the channel sequence used in the broadcast time slot relative to the channel sequence used in the first broadcast time slot of the master node. Optionally, the master node uses the broadcast time slot with the smallest time slot number in the frame period as the first broadcast time slot. However, it should be noted that the position of the first broadcast time slot can be set as needed, for example, the broadcast time slot with the largest time slot number in the frame period can also be used as the first broadcast time slot.

[0080] The broadcast message sent by the master node in its broadcast time slot includes the frequency hopping offset associated with the broadcast time slot sent by the master node and / or the relay slave node in the wireless ad hoc network.

[0081] The relay slave node receives the broadcast message and learns the difference between the frequency hopping offset associated with the broadcast time slot of the node that sends the broadcast message and the frequency hopping offset associated with its own broadcast time slot.

[0082] Figure 5 A schematic diagram showing an exemplary configuration of a broadcast time slot transmission channel, Figure 5 Each node uses Figure 3 The frame structure configuration shown in the figure, after the nodes are synchronized, the topology of the wireless ad hoc network is as follows Figure 1 As shown in the figure, node 1 is the master node, nodes 3, 4, 6, and 8 are configured as relay slave nodes, and nodes 2, 5, and 7 are configured as terminal slave nodes. Figure 5, each node uses the same system frequency hopping sequence, which can be expressed as a channel sequence "f1, f2, f3, f4, f5, f6". Node 1 sends signals in both the first broadcast time slot BR1 and the second broadcast time slot BR2 in its frame structure. Each broadcast time slot used to send signals by each node in the wireless ad hoc network is associated with a frequency hopping offset, which indicates the offset of the channel sequence used when sending signals in its associated broadcast time slot relative to the channel sequence used by the master node in the first broadcast time slot in its frame structure. At this time, the frequency hopping offsets of BR1 and BR2 in the master node's frame structure are 0 and 2, respectively, the frequency hopping offsets of BR1 of nodes 4 and 6 in their frame structures are 3 and 1, respectively, and the frequency hopping offsets of BR2 of nodes 3 and 8 in their frame structures are 4 and 0, respectively.

[0083] Starting from the nth frame, the channels used by the master node to send signals on the first broadcast time slot BR1 of each frame are f1, f2, f3, f4, f5, f6, f1, f2, f3, f4, f5, f6, ... in sequence, with the system frequency hopping sequence as a cycle. The channels used by the master node to send signals on the second broadcast time slot BR2 of each frame are f3, f4, f5, f6, f1, f2, f3, f4, f5, f6, f1, f2, ... in sequence, also with the system frequency hopping sequence as a cycle, but the frequency hopping offset relative to the channel sequence of BR1 is 2.

[0084] The following is an example of node 3, which is similar to the situation for other slave nodes. Node 3 uses the broadcast time slot BR2 in its frame structure to send signals. Starting from the nth frame, the channels used by the master node to send signals on the first broadcast time slot BR1 of each frame are f1, f2, f3, f4, f5, f6, f1, f2, f3, f4, f5, f6, ..., which are cycled with the system frequency hopping sequence. The frequency hopping offset of node 3 in BR2 is 4, so starting from the nth frame, the channels used by node 3 to send signals on BR2 are f5, f6, f1, f2, f3, f4, f5, f6, f1, f2, f3, f4, ..., which are cycled with the system frequency hopping sequence. Figure 5 The frequency channels used by each node to send signals in the broadcast time slot from the nth frame to the n+2th frame are shown.

[0085] In the case where there are multiple system frequency hopping sequences, each channel of a single system frequency hopping sequence can be first mapped to each channel of the system frequency hopping sequence used by each node in sequence, and then based on the case of a single system frequency hopping sequence, the channel sequence used by each node for sending broadcast time slots is obtained, and then the obtained channel sequence based on the single system frequency hopping sequence is replaced with the corresponding channel sequence according to the established mapping relationship. The following is an explanation of the case of two system frequency hopping sequences, and the case of more system frequency hopping sequences is similar.

[0086] The system frequency hopping sequence 1 is represented as "A, B, C, D, E, F", and the system frequency hopping sequence 2 is represented as "G, H, I, J, K, L". Each element of each system frequency hopping sequence represents a channel. Without loss of generality, let Figure 3 Nodes 1, 3, and 4 use system frequency hopping sequence 1, and nodes 6 and 8 use system frequency hopping sequence 2.

[0087] First, each element of the single system frequency hopping sequence is mapped to each system frequency hopping sequence. The mapping relationship is as follows: Figure 6 As shown, for the system frequency hopping sequence 1, the mapping relationship 1 is f1→A, f2→B, ..., f6→F; for the system frequency hopping sequence 2, the mapping relationship 2 is f1→G, f2→H, ..., f6→L.

[0088] Then, based on the single system frequency hopping sequence "f1, f2, f3, f4, f5, f6", according to the frequency hopping offset of the broadcast time slot of each node, the channel allocation of the broadcast time slot of each node is obtained, that is, Figure 5 Results shown.

[0089] Then, for each node, the channel allocation result obtained based on the single system frequency hopping sequence is replaced with the channel of the system frequency hopping sequence 1 or the system frequency hopping sequence 2 according to the corresponding mapping relationship 1 or mapping relationship 2. After the above replacement, the final channel allocation is as follows: Figure 7 shown.

[0090] Those skilled in the art can understand that after the relay slave node obtains synchronization, it can determine the channel it should use when sending signals in the broadcast time slot according to the channel used by the frame synchronization signal received from the parent node, the difference between the frequency hopping offset associated with the broadcast time slot used by its parent node to send the frame synchronization signal and the frequency hopping offset associated with the broadcast time slot used by it to send the frame synchronization signal, and the system frequency hopping sequence used by it and its parent node to send the broadcast time slot. The difference between the frequency hopping offset associated with the broadcast time slot in which the relay slave node receives the frame synchronization signal sent by its parent node and the frequency hopping offset associated with the broadcast time slot in which the relay slave node sends the frame synchronization signal can be used to indicate the offset of the channel sequence used by the broadcast time slot in which the relay slave node receives the frame synchronization signal relative to the channel sequence used by the broadcast time slot in which the relay slave node sends the frame synchronization signal.

[0091] In the present disclosure, control information such as frame period, node frame structure, system frequency hopping sequence, node type, reference node, designated broadcast time slot of reference node, and frequency hopping offset associated with each transmitted broadcast time slot of the node can be pre-configured to each node.

[0092] In order to dynamically manage the wireless ad hoc network to meet different needs, in some embodiments, one or more of the above control information can also be dynamically adjusted by the control center as needed and sent to each node via a global broadcast.

[0093] The global broadcast referred to in the present disclosure means that the master node sends specific information through a broadcast message, and the relay slave node that receives the broadcast message further sends the specific information in its broadcast message, so that all slave nodes that can receive the broadcast message in the entire network can receive this specific information. The master node can achieve global broadcast of the specific information by setting the information type of the information block to "global broadcast" and the information content to the specific information that needs to be broadcast globally. It should be pointed out that the above method is only an exemplary method for achieving global broadcast, and global broadcast can also be achieved by other methods. The present disclosure does not impose any restrictions on the global broadcast method, as long as similar functions can be achieved.

[0094] Figure 8 The structure block diagram of a master node 300 of a wireless ad hoc network according to an embodiment of the present disclosure is shown. The master node 300 can be used to implement various steps and functions executed by the master node in various embodiments of the node synchronization method 100 for a wireless ad hoc network described above.

[0095] like Figure 8 As shown, the master node 300 includes a channel generating unit 310, a frame synchronization signal generating unit 320 and a signal sending unit 300. The channel generating unit 310 is configured to generate a channel used by the frame synchronization channel for sending a frame synchronization signal based on a system frequency hopping sequence associated with the frame synchronization channel; the frame synchronization signal generating unit 320 is configured to generate a frame synchronization signal; and the signal sending unit 330 is configured to use the channel generated by the channel generating unit 310 to send the frame synchronization signal generated by the frame synchronization signal generating unit 320 through the frame synchronization channel.

[0096] Fig. 9 The structure block diagram of a relay slave node 400 of a wireless ad hoc network according to an embodiment of the present disclosure is shown. The relay slave node 400 can be used to implement various steps and functions executed by the relay slave node in various embodiments of the node synchronization method 100 for a wireless ad hoc network described above.

[0097] like Fig. 9As shown, the relay slave node 400 includes a receiving channel generating unit 410, a sending channel generating unit 420, a signal receiving unit 430, a frame synchronization unit 440, a frame synchronization signal generating unit 450 and a signal sending unit 460. The receiving channel generating unit 410 is configured to generate a channel used by a frame synchronization channel for receiving a frame synchronization signal based on a first system frequency hopping sequence, and the first system frequency hopping sequence is a system frequency hopping sequence associated with a frame synchronization channel for receiving a frame synchronization signal by the relay slave node 400; the sending channel generating unit 420 is configured to generate a channel used by a frame synchronization channel for sending a frame synchronization signal based on a second system frequency hopping sequence, and the second frequency hopping sequence is a system frequency hopping sequence associated with a frame synchronization channel used by the relay slave node 400 to send a frame synchronization signal; the signal receiving unit 430 is configured to receive the frame synchronization signal transmitted by the master node 460. The frame synchronization signal is sent by the master node or other relay slave node through the frame synchronization channel; the frame synchronization unit 440 is configured to obtain frame synchronization between itself and the master node or other relay slave node that sends the received frame synchronization signal based on the received frame synchronization signal sent by the master node or other relay slave node; the frame synchronization signal generating unit 450 is configured to generate a frame synchronization signal; the signal sending unit 460 is configured to send the frame synchronization signal generated by the frame synchronization signal generating unit 450 through the frame synchronization channel after obtaining frame synchronization between itself and the master node or other relay slave node that sends the received frame synchronization signal.

[0098] The present disclosure also provides a master node 500 of a wireless ad hoc network, including a processor 510 and a transmitter 520. Fig.10 The transmitter 520 is configured to send a frame synchronization signal under the control of the processor 510; the processor 510 is configured to control the transmitter 520 to send a frame synchronization signal through a frame synchronization channel, and to execute various steps and functions performed by the master node in various embodiments of the node synchronization method 100 for wireless ad hoc networks described above.

[0099] The present disclosure also provides a relay slave node 600 of a wireless ad hoc network, including a processor 610, a receiver 620 and a transmitter 630. Fig.11 As shown. The receiver 620 is configured to receive a frame synchronization signal sent by a master node or other relay slave nodes under the control of the processor 610; the transmitter 630 is configured to send a frame synchronization signal through a frame synchronization channel under the control of the processor 610; the processor 610 is configured to control the receiver 620 to receive a frame synchronization signal sent by a master node or other relay slave nodes, and control the transmitter 620 to send a frame synchronization signal through a frame synchronization channel, and execute the various steps and functions performed by the relay slave node in the various embodiments of the node synchronization method 100 for wireless ad hoc networks described above.

[0100] The present disclosure also provides a master node of a wireless ad hoc network, comprising a processor and a non-transitory storage medium storing computer executable instructions, wherein the computer executable instructions can be executed by the processor to perform various steps and functions performed by the master node in various embodiments of the node synchronization method 100 for a wireless ad hoc network.

[0101] The present disclosure also provides a relay slave node of a wireless ad hoc network, comprising a processor and a non-transitory storage medium storing computer executable instructions, wherein the computer executable instructions can be executed by the processor to perform various steps and functions performed by the relay slave node in various embodiments of the node synchronization method 100 for a wireless ad hoc network.

[0102] A person of ordinary skill in the art can understand and implement other changes to the disclosed embodiments by reading the specification and drawings, the content of the invention and the claims of the present disclosure, and they all fall within the scope of protection of the claims of the present disclosure without departing from the essence of the claims of the present disclosure. In the claims, the wording "comprising" does not exclude other elements and steps, and the words "one" and "an" do not exclude the plural. In the actual application of the present application, a part may perform the functions of multiple technical features cited in the claims. Any figure marks in the claims should not be construed as limiting the scope.

Claims

1. A node synchronization method for a wireless ad hoc network, characterized in that: The wireless ad hoc network comprises a plurality of nodes, wherein the plurality of nodes comprises a master node and at least one relay slave node, and the method comprises: The master node sends a frame synchronization signal; The relay slave node obtains frame synchronization between itself and the master node or other relay slave nodes that sent the received frame synchronization signal based on the received frame synchronization signal sent by the master node or other relay slave nodes; After the relay slave node obtains frame synchronization between itself and the master node or other relay slave nodes that sends the received frame synchronization signal, it sends a frame synchronization signal so that other nodes can obtain frame synchronization with it by receiving the frame synchronization signal sent by it; The frequency channels used by the frame synchronization channels used by the master node and the relay slave node for sending frame synchronization signals are changed based on the system frequency hopping sequence.

2. The method according to claim 1, characterized in that The master node and the relay slave node send frame synchronization signals including: The master node sends a frame synchronization signal on at least one frame synchronization channel included in its frame; After the relay slave node obtains frame synchronization between itself and the master node or other relay slave nodes that sends the received frame synchronization signal based on the received frame synchronization signal sent by the master node or other relay slave nodes, sending the frame synchronization signal includes: The relay slave node receives and tracks a frame synchronization signal sent by a master node or another relay slave node on one of at least two frame synchronization channels included in its frame, and sends a frame synchronization signal on at least one of the at least two frame synchronization channels that is not used to receive and track frame synchronization signals.

3. The method according to claim 1, characterized in that The frequency channels used by the frame synchronization channels of the master node and the relay slave node for sending frame synchronization signals are cyclically changed based on the system frequency hopping sequence.

4. The method according to claim 1, characterized in that The frequency channels used by the frame synchronization channels of the master node and the relay slave node for sending frame synchronization signals are changed at fixed time intervals based on the system frequency hopping sequence, and the fixed time intervals take frames as time units.

5. The method according to claim 3, characterized in that: The frequency channels used by the frame synchronization channels used by the master node and the relay slave node for sending frame synchronization signals are changed based on system frequency hopping sequences of the same length.

6. The method according to claim 1, characterized in that Each frame synchronization channel used to transmit a frame synchronization signal is associated with a frequency hopping offset; The frequency hopping offset associated with the frame synchronization channel is an offset of a frequency channel sequence used by the frame synchronization channel relative to a frequency channel sequence used by a designated frame synchronization channel of a reference node.

7. The method according to claim 6, characterized in that The frequency channels used by the master node and the relay slave node for sending frame synchronization signals are based on the system frequency hopping sequence changes, including: The relay slave node determines the frequency channel used by its frame synchronization channel for sending frame synchronization signals based on the system frequency hopping sequence, the frequency channel on which its received frame synchronization signal is located, and the difference between the frequency hopping offset associated with the frame synchronization channel used to send the received frame synchronization signal and the frequency hopping offset associated with the frame synchronization channel used to send the frame synchronization signal.

8. The method according to claim 6, characterized in that The method further comprises: The master node sends a broadcast message, the broadcast message including a frequency hopping offset associated with a frame synchronization channel used by the master node and / or the relay slave node in the wireless ad hoc network to send a frame synchronization signal; The relay slave node obtains, through the received broadcast message, the difference between the frequency hopping offset associated with the frame synchronization channel used by the node sending the broadcast message to send the frame synchronization signal and the frequency hopping offset associated with the frame synchronization channel used by the relay slave node to send the frame synchronization signal.

9. The method according to claim 8, characterized in that The master node and the relay slave node send the frequency hopping offset associated with the frame synchronization channel used by the master node and the relay slave node in the wireless ad hoc network to send the frame synchronization signal through a global broadcast mode. The method includes: The relay slave node learns the frequency hopping offset associated with the frame synchronization channel used by the master node and / or the relay slave node to send the frame synchronization signal in the wireless ad hoc network by receiving the broadcast message of the master node or other relay slave nodes.

10. The method according to claim 1, characterized in that The master node and / or the relay slave node sends a frame synchronization signal and a broadcast message in one broadcast time slot.

11. The method according to claim 1, characterized in that: The method further comprises: The master node and / or the relay slave node sends a broadcast message, where the broadcast message includes the system frequency hopping sequence; The relay slave node obtains the system frequency hopping sequence by receiving a broadcast message sent by the master node or other relay slave nodes.

12. The method according to claim 1, characterized in that The method further comprises: The master node and / or the relay slave node sends a broadcast message, which includes configuration information of the frame synchronization relationship between nodes in the wireless ad hoc network; The relay slave node learns the parent node assigned to the relay slave node receiving the broadcast message by receiving the broadcast message sent by the master node or other relay slave nodes, and then obtains frame synchronization with its parent node by receiving the frame synchronization signal sent by its parent node.

13. The method according to claim 2, characterized in that The master node sends a frame synchronization signal on at least two frame synchronization channels included in one frame.

14. A method for node synchronization in a wireless ad hoc network, characterized in that: The wireless ad hoc network includes a plurality of nodes, the plurality of nodes include a master node and at least one relay slave node, the method is applied to the master node, and the method includes: Sending a frame synchronization signal via a frame synchronization channel; The frequency channel used by the frame synchronization channel for sending the frame synchronization signal changes based on the system frequency hopping sequence associated with the frame synchronization channel.

15. The method according to claim 14, characterized in that The frequency channel used by the frame synchronization channel changes at fixed time intervals based on a system frequency hopping sequence, and the fixed time intervals use frames as time units.

16. The method according to claim 14, characterized in that The frame synchronization channel is included in the broadcast time slot.

17. The method according to claim 14, characterized in that The method further comprises: A broadcast message is sent through a broadcast channel, wherein the broadcast message includes a frequency hopping offset associated with a frame synchronization channel used by other nodes in the wireless ad hoc network to send a frame synchronization signal.

18. A method for node synchronization in a wireless ad hoc network, characterized in that: The wireless ad hoc network includes a plurality of nodes, the plurality of nodes include a master node and at least one relay slave node, the method is applied to the relay slave node, and the method includes: Receiving a frame synchronization signal sent by a master node or other relay slave node, and based on the received frame synchronization signal sent by the master node or other relay slave node, obtaining frame synchronization between itself and the master node or other relay slave node that sent the received frame synchronization signal; After obtaining frame synchronization between itself and the master node or other relay slave node that sends the received frame synchronization signal, send the frame synchronization signal through the frame synchronization channel so that other nodes can obtain frame synchronization with it by receiving the frame synchronization signal sent by it; The frequency channel used by the frame synchronization channel used by the relay slave node to send the frame synchronization signal changes based on the system frequency hopping sequence associated with the frame synchronization channel.

19. The method according to claim 18, characterized in that The frequency channel used by the frame synchronization channel for sending the frame synchronization signal by the relay slave node changes at fixed time intervals based on the system frequency hopping sequence, and the fixed time intervals take frames as time units.

20. The method according to claim 18, characterized in that The frame synchronization channel is included in the broadcast time slot.

21. The method according to claim 18, characterized in that The frame synchronization channel used by the relay slave node to send a frame synchronization signal is associated with a frequency hopping offset, which is an offset of a frequency channel sequence used by the frame synchronization channel relative to a frequency channel sequence used by a designated frame synchronization channel of a reference node.

22. A master node of a wireless ad hoc network, characterized in that: include: a channel generating unit configured to generate a channel used by a frame synchronization channel for transmitting a frame synchronization signal based on a system frequency hopping sequence; a frame synchronization signal generating unit, configured to generate a frame synchronization signal; as well as A signal sending unit is configured to send the frame synchronization signal through the frame synchronization channel.

23. A relay slave node of a wireless ad hoc network, characterized in that: include: a receiving channel generating unit, configured to generate a channel used by a frame synchronization channel for receiving a frame synchronization signal based on a first system frequency hopping sequence; a transmission channel generating unit, configured to generate a channel used by a frame synchronization channel for transmitting a frame synchronization signal based on a second system frequency hopping sequence; a signal receiving unit configured to receive a frame synchronization signal sent by a master node or other relay slave nodes through a frame synchronization channel; a frame synchronization unit configured to obtain frame synchronization between itself and the master node or other relay slave node that transmits the received frame synchronization signal based on a received frame synchronization signal transmitted by the master node or other relay slave node; a frame synchronization signal generating unit, configured to generate a frame synchronization signal; as well as A signal sending unit is configured to send the frame synchronization signal through a frame synchronization channel after obtaining frame synchronization between itself and a master node or other relay slave node that sends the received frame synchronization signal.

24. A master node of a wireless ad hoc network, comprising a processor and a non-transitory storage medium storing computer executable instructions, characterized in that: The computer executable instructions may be executed by the processor to perform the method of any one of claims 14 to 17.

25. A relay slave node of a wireless ad hoc network, comprising a processor and a non-transitory storage medium storing computer executable instructions, characterized in that: The computer executable instructions may be executed by the processor to perform the method of any one of claims 18 to 21.

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