CN113613326A - Ad hoc network node synchronization method, device and storage medium - Google Patents
Ad hoc network node synchronization method, device and storage medium Download PDFInfo
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Abstract
The invention discloses a method, a device and a storage medium for synchronizing ad hoc network nodes, wherein the method comprises the following steps: receiving a radio wave message sent by a target node, and recording the current time slot when the radio wave message is received according to a local clock; obtaining an offset time slot between any node and the target node according to the current time slot and a first preset message sending time slot of the target node; and updating a second preset message sending time slot of any node in the local clock according to the offset time slot so as to align the time slots of all nodes of the Mesh network. The second preset message sending time slot of any node in the Mesh network is aligned with the first preset message sending time slot of the target node, so that all nodes in the Mesh network realize clock alignment, and the technical effect of avoiding the mutual conflict of the message sending time slots of the nodes is achieved.
Description
Technical Field
The present invention relates to the field of wireless ad hoc network communication technologies, and in particular, to a method, a device, and a storage medium for synchronizing ad hoc network nodes.
Background
The Mesh networking is a centerless and Mesh structure network, all nodes in the Mesh network are mutually connected, each node is provided with a plurality of connecting channels, when a certain line is blocked or has no response, the Mesh network can select other lines according to the situation to carry out data rebroadcast, the fault of any node does not influence the access of the network, and the network can be automatically repaired when the network has the fault, so that the high-speed and smooth network is ensured.
The Mesh network is applied to large-scale networking and has the characteristics of simple installation, automatic networking, large coverage area, long transmission distance, strong robustness and the like, but the Mesh networking has no uniform standard, so the interoperability is poor, for large-scale networking communication, a node text time slot in the networking is usually fixed, each node of the ad hoc network takes a local clock as reference, and when a plurality of nodes have text sending requirements, the text sending time slots of the nodes are easy to conflict, so that signals cannot be normally demodulated and the communication fails.
Therefore, the problem that the message sending time slots of the nodes are easy to conflict in the existing large-scale ad hoc network mode, and communication failure is caused is solved.
Disclosure of Invention
The invention mainly aims to provide a method, equipment and a storage medium for synchronizing ad hoc network nodes, and aims to solve the technical problem that communication fails due to the fact that node message sending time slots are easy to conflict in the existing large-scale ad hoc network mode.
According to a first aspect of the present invention, there is provided a method for synchronizing ad hoc network nodes, the method being applied to any node in a Mesh network, wherein any node has a corresponding preset message sending time slot;
the method comprises the following steps:
receiving a radio wave message sent by a target node, and recording the current time slot when the radio wave message is received according to a local clock;
obtaining an offset time slot between any one node and the target node according to the current time slot and a first preset message sending time slot of the target node;
and updating a second preset message sending time slot of any node in the local clock according to the offset time slot so as to align the time slots of all nodes of the Mesh network.
Optionally, the any node has a second node ID;
the step of receiving a radio wave packet sent by a target node and recording a current time slot when the radio wave packet is received according to a local clock includes:
receiving a radio wave message sent by a target node;
analyzing a message header of the radio wave message to obtain first routing information; wherein the first routing information comprises a first node ID;
judging whether the first node ID is consistent with the second node ID;
and if the first node ID is consistent with the second node ID, recording the current time slot when the radio wave message is received according to a local clock.
Optionally, the message data of the radio wave message includes a source IP address and a destination IP address;
after the step of parsing the header of the radio wave packet, the method further includes:
if the message header is a preset value, searching whether the source IP address and the destination IP address exist in a local memory;
and if the source IP address and the destination IP address do not exist in the local memory, storing the radio wave message, and forwarding the radio wave message to at least one node corresponding to a preset multicast address range.
Optionally, after the step of determining whether the first node ID is consistent with the second node ID, the method further includes:
and if the first node ID is not consistent with the second node ID, discarding the first radio wave message.
Optionally, the step of obtaining an offset time slot between the any node and the target node according to the current time slot and the first preset message sending time slot of the target node includes:
and obtaining a difference value between the current time slot and a first preset message sending time slot of the target node according to the current time slot and the first preset message sending time slot, and determining the difference value as an offset time slot between any node and the target node.
According to a second aspect of the present invention, there is provided a method for synchronizing ad hoc network nodes, the method is used for a target node in a Mesh network, and any node in the Mesh network has a corresponding preset message sending time slot;
the method comprises the following steps:
when a current frame is in a first preset message sending time slot, sending a radio wave message to any node so that the any node records a current time slot when receiving the radio wave message according to a local clock, obtaining an offset time slot between the any node and the target node according to the current time slot and the first preset message sending time slot of the target node, and updating a second preset message sending time slot of the any node in the local clock according to the offset time slot so that the time slots of all nodes of the Mesh network are aligned.
Optionally, the target node stores an ARP address resolution protocol table and a routing table, where the ARP table includes a first destination address, the routing table includes first routing information, and the first routing information includes a destination node ID;
before the step of sending the radio wave packet to the any node, the method further includes:
obtaining a target destination address of any node;
searching whether a first destination address consistent with the target destination address exists in the ARP table or not; the ARP table further comprises a first node ID corresponding to the first destination address;
if a first destination address consistent with the target destination address exists in the ARP table, acquiring the first node ID;
judging whether the ID of the destination node is consistent with the ID of the first node;
and if the destination node ID is consistent with the first node ID, storing the first routing information into a message header of the radio wave message.
Optionally, after the step of determining whether the destination node ID is consistent with the first node ID, the method further includes:
and if the destination node ID is inconsistent with the first node ID, storing a preset value into a message header of the radio wave message.
According to a third aspect of the present invention, there is provided an ad hoc network node synchronization apparatus, which is used for any node in a Mesh network, where any node has a corresponding preset message sending time slot;
the device comprises:
the receiving module is used for receiving the radio wave message sent by the target node and recording the current time slot when the radio wave message is received according to a local clock;
an obtaining module, configured to obtain an offset time slot between the any node and the target node according to the current time slot and a first preset message sending time slot of the target node;
and the updating module updates a second preset message sending time slot of the local clock of any node according to the offset time slot so as to align the time slots of all nodes of the Mesh network.
According to a fourth aspect of the present invention, there is provided an ad hoc network node synchronization apparatus, which is used for a target node in a Mesh network, where any node in the Mesh network has a corresponding preset message sending time slot;
the device comprises:
and the sending module is used for sending a radio wave message to any node when a current frame is in a first preset message sending time slot so as to enable the any node to record the current time slot when the radio wave message is received according to a local clock, obtaining the offset time slot between the any node and the target node according to the current time slot and the first preset message sending time slot of the target node, and updating the second preset message sending time slot of the any node in the local clock according to the offset time slot so as to enable the time slots of all nodes of the Mesh network to be aligned.
According to a fifth aspect of the present invention, there is provided an ad hoc network node synchronization apparatus, comprising: a memory, a processor and an ad hoc network node synchronization program stored in the memory and executable on the processor, which when executed by the processor implements the steps described in any one of the possible implementations of the first and second aspects.
According to a sixth aspect of the present invention, there is provided a computer storage medium having stored thereon an ad hoc network node synchronization program which, when executed by a processor, implements the steps described in any one of the possible implementations of the first and second aspects.
The invention discloses a method, a device and a storage medium for synchronizing ad hoc network nodes, wherein the method comprises the following steps: receiving a radio wave message sent by a target node, and recording the current time slot when the radio wave message is received according to a local clock; obtaining an offset time slot between any one node and the target node according to the current time slot and a first preset message sending time slot of the target node; and updating a second preset message sending time slot of any node in the local clock according to the offset time slot so as to align the time slots of all nodes of the Mesh network. The second preset message sending time slot of any node in the Mesh network is aligned with the first preset message sending time slot of the target node, so that all nodes in the Mesh network realize clock alignment, and the technical effect of avoiding the mutual conflict of the message sending time slots of the nodes is achieved.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the provided drawings without creative efforts.
Fig. 1 is a schematic structural diagram of an ad hoc network node synchronization device in a hardware operating environment according to an embodiment of the present invention;
fig. 2 is a flowchart illustrating a first embodiment of a method for synchronizing ad hoc networks nodes according to the present invention;
fig. 3 is a block diagram of a first embodiment of an ad hoc network node synchronization apparatus according to the present invention;
fig. 4 is a block diagram of a second embodiment of an ad hoc network node synchronization apparatus according to the present invention.
The implementation, functional features and advantages of the objects of the present invention will be further explained with reference to the accompanying drawings.
Detailed Description
It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.
The main solution of the embodiment of the invention is as follows: receiving a radio wave message sent by a target node, and recording the current time slot when the radio wave message is received according to a local clock; obtaining an offset time slot between any one node and the target node according to the current time slot and a first preset message sending time slot of the target node; and updating a second preset message sending time slot of any node in the local clock according to the offset time slot so as to align the time slots of all nodes of the Mesh network.
The invention provides a solution, which aligns the second preset message sending time slot of any node in the Mesh network with the first preset message sending time slot of the target node, thereby realizing clock alignment of all nodes in the Mesh network and achieving the technical effect of avoiding mutual conflict of the message sending time slots of the nodes.
In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all, embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
Where "first" and "second" are used in the description and claims of embodiments of the invention to distinguish between similar elements and not necessarily for describing a particular sequential or chronological order, it is to be understood that such data may be interchanged where appropriate so that embodiments described herein may be implemented in other sequences than those illustrated or described herein.
Referring to fig. 1, fig. 1 is a schematic structural diagram of an ad hoc network node synchronization device in a hardware operating environment according to an embodiment of the present invention.
In general, an ad hoc network node synchronization apparatus includes: at least one processor 1001, a memory 1002, and an ad hoc network node synchronization program stored on the memory and executable on the processor, the ad hoc network node synchronization program being configured to implement the steps of the ad hoc network node synchronization method as described above.
In some embodiments, the ad hoc network node synchronization device may further include: a communication interface 1003 and at least one peripheral device. The processor 1001, the memory 1002, and the communication interface 1003 may be connected by a bus or signal line. Various peripheral devices may be connected to communications interface 1003 via a bus, signal line, or circuit board.
The communication interface 1003 may be used to connect at least one peripheral device related to I/O (Input/Output) to the processor 1001 and the memory 1002. In some embodiments, processor 1001, memory 1002, and communication interface 1003 are integrated on the same chip or circuit board; in some other embodiments, any one or two of the processor 1001, the memory 1002 and the communication interface 1003 may be implemented on separate chips or circuit boards, which is not limited by the embodiment.
Those skilled in the art will appreciate that the architecture shown in figure 1 does not constitute a limitation of ad hoc network node synchronization devices and may include more or fewer components than shown, or some components in combination, or a different arrangement of components.
Based on the hardware structure, the embodiment of the ad hoc network node synchronization method is provided.
Referring to fig. 2, fig. 2 is a schematic flowchart of a first embodiment of a method for synchronizing ad hoc network nodes, which is used for any node in a Mesh network, where any node has a corresponding preset message sending time slot, and the method includes the following steps:
s200, receiving a radio wave message sent by a target node, and recording the current time slot when the radio wave message is received according to a local clock;
it should be noted that the main execution body of the method of this embodiment is any node in the Mesh network, the Mesh network divides the channel into a plurality of slots (slots), the slots are used as basic units for data transceiving, and the nodes in the network occupy at least one slot to complete the operations of channel contention and allocation, data transceiving, link maintenance, and the like. In this embodiment, the Mesh network performs data transmission based on Time Division Multiple Access (TDMA), and its transmission units are divided by a Time dimension, where a duration of each Time slot may be 1ms, any node in the Mesh network has a second node ID and a preset message slot, the second node ID may be used to identify a node, and corresponds to the preset message slot one to one, and a correspondence relationship may be shown in the following table:
| node 1 | Node 2 | Node 3 | …… | |
| Second node ID | 1 | 2 | 3 | …… |
| Presetting message time slot | Tx1＝10ms | Tx2＝15ms | Tx3＝20ms | …… |
The preset message sending time slots of each node in the Mesh network are fixedly distributed and correspond to the IDs of the second nodes one to one, and because each node in the large-scale ad hoc network uses the local clock as reference, when a plurality of nodes have message sending requirements, the message sending time slots of the nodes are easy to conflict, so that signals cannot be demodulated normally and communication fails. In this embodiment, the target node may be a node with the smallest node ID, and other nodes in the network all align to the local clock of the target node, so that each node realizes clock alignment, and mutual collision of message sending time slots of the nodes is avoided.
It can be understood that any node in the Mesh network receives the radio wave packet sent by the target node, and records the current time slot Rx when the radio wave packet is received according to the local clock. The target node may send the radio wave packet in a unicast mode, or may send the radio wave packet in a multicast mode. The target node sends a radio wave message at a first preset message sending time slot Tx1, and the target node corresponds to the first preset message sending time slot.
It should be understood that, if the target node is the node with the smallest node ID in the Mesh network, the node with the smallest node ID should be powered up earlier than the rest of the nodes. It will be appreciated that powering up a node is powering up the device in which the node is located.
Further, the any node has a second node ID;
the specific implementation process of step S200 includes:
s220, receiving a radio wave message sent by a target node;
s240, analyzing the message header of the radio wave message to obtain first routing information; wherein the first routing information comprises a first node ID;
it should be noted that the header of the radio wave packet stores the routing information, and the header of the radio wave packet sent by the target node stores the first routing information.
In this embodiment, if the target node transmits the radio wave packet in a unicast manner, any node parses a packet header of the radio wave packet transmitted by the target node, and may obtain the first routing information, where the first routing information includes a first node ID, and the first node ID may be a node ID of a radio wave packet transmission target.
Further, the message data of the radio wave message includes a source IP address and a destination IP address;
in step S240, after parsing the header of the radio wave packet, the method further includes:
s242, if the message header is a preset value, searching whether the source IP address and the destination IP address exist in a local memory;
in this embodiment, if the target node sends the radio wave packet in a multicast mode, any node analyzes the packet header of the radio wave packet sent by the target node, and a preset value can be obtained.
It should be noted that the preset value is a preset value before networking, and the value is a value other than all node IDs, for example, the range of the node IDs is 1 to 50, and the preset value is a value out of the range of the node IDs, and may be 100, 1000, and the like.
It can be understood that, if the packet header is analyzed to obtain the preset value, any node obtains first multicast data information in the packet data of the radio wave packet according to the transmission protocol, where the first multicast data information includes a first source IP address, a first destination IP address, a first source port, a first destination port, and the like, and stores the first multicast data information in the local memory. When any node receives the radio wave message with the message header of the preset value again, the second multicast data information of the radio wave message received again is obtained, whether the first multicast data information consistent with the second multicast data information exists in the local memory is searched, if yes, the radio wave message received again is discarded, and the method can avoid the problem that the same multicast data is processed by the node, so that the resource waste is caused.
In this embodiment, if the packet header is analyzed to obtain the preset value, whether the source IP address and the destination IP address of the radio wave packet data exist in the local memory is searched, so as to determine whether the packet data is received repeatedly. It can be understood that whether the source port and the destination port of the radio wave packet data or other data related to the multicast data information exist in the local memory may also be searched to determine whether the multicast data information is received repeatedly.
S244, if the source IP address and the destination IP address do not exist in the local memory, storing the radio wave packet, and forwarding the radio wave packet to at least one node corresponding to a preset multicast address range.
It can be understood that, if the source IP address and the destination IP address of the radio wave packet data do not exist in the local memory of any node, which indicates that the radio wave packet is received for the first time, the radio wave packet is stored, and the radio wave packet is forwarded to at least one node corresponding to the preset multicast address range. It can be understood that the radio wave packet is stored, and the multicast data information in the radio wave packet data is also stored. In addition, the multicast address range is preset and may range from 224.0.0.0 to 239.255.255.255.
S260, judging whether the first node ID is consistent with the second node ID;
note that any node has a second node ID, and when the nodes are different, the second node IDs are also different.
In this embodiment, by determining whether the first node ID is consistent with the second node ID, any node can know whether the radio wave packet is sent to itself.
Further, after step S260, the method further includes:
s262, if the first node ID is not consistent with the second node ID, discarding the first radio wave packet.
It is understood that, if the first node ID is not consistent with the second node ID, it indicates that the target node does not send the radio wave packet to any node corresponding to the second node ID, and therefore any node receiving the radio wave packet discards the radio wave packet.
And S280, if the first node ID is consistent with the second node ID, recording the current time slot when the radio wave message is received according to a local clock.
It can be understood that, if the first node ID is consistent with the second node ID, it indicates that the target node sends the radio wave packet to any node corresponding to the second node ID, and therefore, any node receiving the radio wave packet records the current time slot when receiving the radio wave packet according to the local clock.
S400, obtaining an offset time slot between any node and the target node according to the current time slot and a first preset message sending time slot of the target node;
it should be noted that, the Offset time slot Offset between any node and the destination node can be obtained according to the current time slot Rx when any node receives the radio wave packet and the first preset message time slot Tx1 of the destination node.
Further, the specific implementation process of step S400 includes:
s402, obtaining a difference value between the current time slot and a first preset message sending time slot of the target node according to the current time slot and the first preset message sending time slot, and determining the difference value as an offset time slot between any one node and the target node.
In this embodiment, the difference between the current time slot and the first predetermined message time slot is obtained according to the current time slot Rx and the first predetermined message time slot Tx1, and the difference is determined as the Offset time slot Offset between any one of the aforementioned nodes and the target node, that is, the Offset is obtained by calculating Rx-Tx 1.
It can be understood that if Rx > Tx1, it means that the local clock of any one of the aforementioned nodes is faster than the local clock of the target node, and the obtained offset time slot is a positive number; if Rx is less than Tx1, the local clock of any node is slower than that of the target node, and the obtained offset time slot is a negative number; if Rx is Tx1, it means that the local clock of any node is consistent with the local clock of the target node.
It should be understood that Offset can also be obtained by Tx1-Rx, and the subsequent steps can be adjusted accordingly.
And S600, updating a second preset message sending time slot of any node in the local clock according to the offset time slot so as to align the time slots of all nodes of the Mesh network.
In this embodiment, any node updates the second preset message sending time slot in the local clock according to the calculated offset time slot, so that the time slots of the nodes in the Mesh network are aligned. The second preset message sending time slot corresponds to any node, and it can be understood that when the nodes are different, the second preset message sending time slot is also different.
Further, the specific implementation process of step S600 includes:
and S602, obtaining a summation value of the offset time slot and the second preset message sending time slot according to the offset time slot, and updating the second preset message sending time slot of the local clock of any node to the summation value.
It should be noted that the offset time slot between any node and the target node is obtained to adjust the message time slot of any node, so that any node is aligned with the local clock of the target node. In this embodiment, a summation value of the offset time slot and the second preset message time slot is obtained, and the second preset message time slot of the local clock of any node is updated to the summation value.
It can be understood that if the local clock of any node is faster than the local clock of the target node, and the offset time slot is a positive number, the message sending time slot of any node needs to be slowed down, that is, the offset time slot is added on the basis of the second preset message sending time slot; if the local clock of any node is slower than the local clock of the target node and the offset time slot is a negative number, the message time slot of any node needs to be adjusted faster, that is, the absolute value of the offset time slot is subtracted on the basis of the second preset message time slot, that is, the offset time slot is added on the basis of the second preset message time slot. For example: if the current time slot Rx is 5ms, the first predetermined message time slot Tx1 is 10ms, and the second predetermined message time slot Tx2 is 15ms, then the Offset time slot Offset is Rx-Tx1 is-5 ms, and it is known that the local clock of any node is 5ms slower than the local clock of the target node, then the Offset time slot is added to the second predetermined message time slot to obtain a summation value of 10ms, where 10ms is an updated value of the second predetermined message time slot, that is, the actual message time slot of any node is 10 ms.
It should be noted that, if the node with the minimum node ID in the Mesh network is powered on later, the target node may be an adjacent node of the node with the minimum node ID, where the adjacent node is a powered-on node, and when the node with the minimum node ID is powered on, the node with the minimum node ID first receives the radio wave packet of the adjacent node, and aligns the local clock of the adjacent node according to the foregoing steps. And when the node with the minimum node ID is aligned with the local clock of the adjacent node, taking the node with the minimum node ID as a target node, and sending the radio wave message to other nodes. It is understood that there may be more than one neighboring node of the node ID minimum node, and the neighboring node of the node ID minimum node that receives the radio wave packet is the node that is powered on and is closest to the node ID minimum node.
Through the above embodiment, a radio wave message sent by a target node is received, and a current time slot when the radio wave message is received is recorded according to a local clock; obtaining an offset time slot between any one node and the target node according to the current time slot and a first preset message sending time slot of the target node; and updating a second preset message sending time slot of any node in the local clock according to the offset time slot so as to align the time slots of all nodes of the Mesh network. The second preset message sending time slot of any node in the Mesh network is aligned with the first preset message sending time slot of the target node, so that all nodes in the Mesh network realize clock alignment, and the technical effect of avoiding the mutual conflict of the message sending time slots of the nodes is achieved.
As an embodiment of the present invention, the ad hoc network node synchronization method may also be used for a target node in a Mesh network, where any node in the Mesh network has a corresponding preset message sending time slot;
the method comprises the following steps:
and S100, when a current frame is in a first preset message sending time slot, sending a radio wave message to any node so that the any node records a current time slot when the radio wave message is received according to a local clock, obtaining an offset time slot between the any node and the target node according to the current time slot and the first preset message sending time slot of the target node, and updating a second preset message sending time slot of the any node in the local clock according to the offset time slot so that the time slots of all nodes of the Mesh network are aligned.
It should be noted that the main execution body of the method of this embodiment is a target node in the Mesh network, the Mesh network divides a channel into a plurality of slots (slots), the slots are used as basic units for data transceiving, and the nodes in the network occupy at least one slot to complete operations such as channel contention and allocation, data transceiving, link maintenance, and the like. In this embodiment, the Mesh network performs data transmission based on Time Division Multiple Access (TDMA), and its transmission units are divided by a Time dimension, where a duration of each Time slot may be 1ms, any node in the Mesh network has a second node ID and a preset message slot, the second node ID may be used to identify a node, and corresponds to the preset message slot one to one, and a correspondence relationship may be shown in the following table:
| node 1 | Node 2 | Node 3 | …… | |
| Second node ID | 1 | 2 | 3 | …… |
| Presetting message time slot | Tx1＝10ms | Tx2＝15ms | Tx3＝20ms | …… |
The preset message sending time slots of each node in the Mesh network are fixedly distributed and correspond to the IDs of the second nodes one to one, and because each node in the large-scale ad hoc network uses the local clock as reference, when a plurality of nodes have message sending requirements, the message sending time slots of the nodes are easy to conflict, so that signals cannot be demodulated normally and communication fails. In this embodiment, the target node may be a node with the smallest node ID, and other nodes in the network all align to the local clock of the target node, so that each node realizes clock alignment, and mutual collision of message sending time slots of the nodes is avoided.
It should be noted that, because some nodes in the Mesh network may be far away from the target node, the target node may send the vod packet to the relay node first and then the relay node forwards the vod packet to the second node, in consideration of the channel quality. It can be understood that the second node is any one of the nodes in the Mesh network which are far away from the target node.
It can be understood that, when the current frame is in the first preset message sending time slot, the target node sends a radio wave message to any node, so that any node records the current time slot Rx when the message information is received according to the local clock. The target node may send the radio wave packet in a unicast mode, or may send the radio wave packet in a multicast mode. The target node sends a radio wave message at a first preset message sending time slot Tx1, and the target node corresponds to the first preset message sending time slot.
It should be understood that, if the target node is the node with the smallest node ID in the Mesh network, the node with the smallest node ID should be powered up earlier than the rest of the nodes. It will be appreciated that powering up a node is powering up the device in which the node is located.
It should be noted that the header of the radio wave packet stores the routing information, and the header of the radio wave packet sent by the target node stores the first routing information.
In this embodiment, if the target node transmits the radio wave packet in a unicast manner, any node parses a packet header of the radio wave packet transmitted by the target node, and may obtain the first routing information, where the first routing information includes a first node ID, and the first node ID may be a node ID of a radio wave packet transmission target.
In this embodiment, if the target node sends the radio wave packet in a multicast mode, any node analyzes the packet header of the radio wave packet sent by the target node, and a preset value can be obtained.
It should be noted that the preset value is a preset value before networking, and the value is a value other than all node IDs, for example, the range of the node IDs is 1 to 50, and the preset value is a value out of the range of the node IDs, and may be 100, 1000, and the like.
It can be understood that, if the packet header is analyzed to obtain the preset value, any node obtains first multicast data information in the packet data of the radio wave packet according to the transmission protocol, where the first multicast data information includes a first source IP address, a first destination IP address, a first source port, a first destination port, and the like, and stores the first multicast data information in the local memory. When any node receives the radio wave message with the message header of the preset value again, the second multicast data information of the radio wave message received again is obtained, whether the first multicast data information consistent with the second multicast data information exists in the local memory is searched, if yes, the radio wave message received again is discarded, and the method can avoid the resource waste caused by processing the same multicast data by nodes.
In this embodiment, if the packet header is analyzed to obtain the preset value, whether the source IP address and the destination IP address of the radio wave packet data exist in the local memory is searched, so as to determine whether the packet data is received repeatedly. It can be understood that whether the source port and the destination port of the radio wave packet data or other data related to the multicast data information exist in the local memory may also be searched to determine whether the multicast data information is received repeatedly.
It can be understood that, if the source IP address and the destination IP address of the radio wave packet data do not exist in the local memory of any node, which indicates that the radio wave packet is received for the first time, the radio wave packet is stored, and the radio wave packet is forwarded to at least one node corresponding to the preset multicast address range. It can be understood that the radio wave packet is stored, and the multicast data information in the radio wave packet data is also stored. In addition, the multicast address range is preset and may range from 224.0.0.0 to 239.255.255.255.
Note that any node has a second node ID, and when the nodes are different, the second node IDs are also different.
In this embodiment, by determining whether the first node ID is consistent with the second node ID, any node can know whether the radio wave packet is sent to itself.
It is understood that, if the first node ID is not consistent with the second node ID, it indicates that the target node does not send the radio wave packet to any node corresponding to the second node ID, and therefore any node receiving the radio wave packet discards the radio wave packet.
It can be understood that, if the first node ID is consistent with the second node ID, it indicates that the target node sends the radio wave packet to any node corresponding to the second node ID, and therefore, any node receiving the radio wave packet records the current time slot when receiving the radio wave packet according to the local clock.
It should be noted that, the Offset time slot Offset between any node and the destination node can be obtained according to the current time slot Rx when any node receives the radio wave packet and the first preset message time slot Tx1 of the destination node.
In this embodiment, the difference between the current time slot and the first predetermined message time slot is obtained according to the current time slot Rx and the first predetermined message time slot Tx1, and the difference is determined as the Offset time slot Offset between any one of the aforementioned nodes and the target node, that is, the Offset is obtained by calculating Rx-Tx 1.
It can be understood that if Rx > Tx1, it means that the local clock of any one of the aforementioned nodes is faster than the local clock of the target node, and the obtained offset time slot is a positive number; if Rx is less than Tx1, the local clock of any node is slower than that of the target node, and the obtained offset time slot is a negative number; if Rx is Tx1, it means that the local clock of any node is consistent with the local clock of the target node.
It should be understood that Offset can also be obtained by Tx1-Rx, and the subsequent steps can be adjusted accordingly.
In this embodiment, any node updates the second preset message sending time slot in the local clock according to the calculated offset time slot, so that the time slots of the nodes in the Mesh network are aligned. The second preset message sending time slot corresponds to any node, and it can be understood that when the nodes are different, the second preset message sending time slot is also different.
It should be noted that the offset time slot between any node and the target node is obtained to adjust the message time slot of any node, so that any node is aligned with the local clock of the target node. In this embodiment, a summation value of the offset time slot and the second preset message time slot is obtained, and the second preset message time slot of the local clock of any node is updated to the summation value.
It can be understood that if the local clock of any node is faster than the local clock of the target node, and the offset time slot is a positive number, the message sending time slot of any node needs to be slowed down, that is, the offset time slot is added on the basis of the second preset message sending time slot; if the local clock of any node is slower than the local clock of the target node and the offset time slot is a negative number, the message time slot of any node needs to be adjusted faster, that is, the absolute value of the offset time slot is subtracted on the basis of the second preset message time slot, that is, the offset time slot is added on the basis of the second preset message time slot. For example: if the current time slot Rx is 5ms, the first predetermined message time slot Tx1 is 10ms, and the second predetermined message time slot Tx2 is 15ms, then the Offset time slot Offset is Rx-Tx1 is-5 ms, and it is known that the local clock of any node is 5ms slower than the local clock of the target node, then the Offset time slot is added to the second predetermined message time slot to obtain a summation value of 10ms, where 10ms is an updated value of the second predetermined message time slot, that is, the actual message time slot of any node is 10 ms.
It should be noted that, if the node with the minimum node ID in the Mesh network is powered on later, the target node may be an adjacent node of the node with the minimum node ID, where the adjacent node is a powered-on node, and when the node with the minimum node ID is powered on, the node with the minimum node ID first receives the radio wave packet of the adjacent node, and aligns the local clock of the adjacent node according to the foregoing steps. And when the node with the minimum node ID is aligned with the local clock of the adjacent node, taking the node with the minimum node ID as a target node, and sending the radio wave message to other nodes. It is understood that there may be more than one neighboring node of the node ID minimum node, and the neighboring node of the node ID minimum node that receives the radio wave packet is the node that is powered on and is closest to the node ID minimum node.
Further, the target node stores an ARP (address resolution protocol) table and a routing table, the ARP table comprises a first destination address, the routing table comprises first routing information, and the first routing information comprises a destination node ID;
it should be noted that any node in the Mesh network stores an ARP table and a routing table, the routing table includes routing information, the routing information includes a node ID, and the ARP table may include other node IDs and destination addresses communicated with any node. Each node in the Mesh network obtains information such as node ID, destination address and the like of other nodes through signaling packets among the nodes, and records the information into an ARP table.
Taking the target node as an example, the destination node ID is stored in the routing table of the target node, and the destination node ID may be a node ID of an object of the target node sending the radio wave packet, or may be a preset value; the ARP table of the target node includes a first node ID and a first destination address, which may be as shown in the following table:
| first node ID | First destination address | |
| Node 2 | 2 | 192.168.0.2 |
| Node 3 | 3 | 192.168.0.3 |
| …… | …… | …… |
| Node n | n | …… |
Before step S100, the method further includes:
s010, obtaining a target destination address of any node;
it should be noted that the target node transmits the radio wave packet to any node, and when it is determined to transmit the radio wave packet, any node is the determined at least one node, so that the target destination address of any node can be obtained.
S030, searching whether a first destination address consistent with the target destination address exists in the ARP table; the ARP table further comprises a first node ID corresponding to the first destination address;
it should be noted that, after the target node obtains the target destination address of any node, it may search from the ARP table whether the first destination address consistent with the target destination address exists. It is to be understood that the ARP table also includes a first node ID corresponding to the first destination address.
S050, if a first destination address consistent with the target destination address exists in the ARP table, acquiring the first node ID;
it should be noted that, if the target node finds the first destination address consistent with the target destination address in the ARP table, it is indicated that any one of the nodes is a node existing in the Mesh network, and meanwhile, the target node obtains the first node ID corresponding to the first destination address.
S070, judging whether the destination node ID is consistent with the first node ID;
it should be noted that the destination node ID is stored in the routing table of the destination node, and the destination node ID may be a node ID of an object of the destination node sending the radio wave packet. By judging whether the destination node ID is consistent with the first node ID, whether the node corresponding to the destination address is the node of the destination node sending the radio wave message object can be judged.
Further, after step S070, the method further includes:
and S080, if the destination node ID is inconsistent with the first node ID, storing a preset value into a message header of the radio wave message.
If the destination node ID is inconsistent with the first node ID, the node corresponding to the destination address is not the node of the object of the destination node sending the radio wave message, so that the destination node stores the preset value into the message header of the radio wave message, and multi-hop or multicast is performed.
S090, if the destination node ID is consistent with the first node ID, storing the first routing information in a header of the radio wave packet.
If the destination node ID is consistent with the first node ID, it is indicated that the node corresponding to the destination address is the node of the object of the destination node sending the radio wave message, so that the destination node stores the first routing information in the header of the radio wave message, and after receiving the radio wave message, the node corresponding to the destination address can know that the radio wave message is the radio wave message sent to the destination node through analyzing the header of the radio wave message.
Through the above embodiments, when a current frame is in a first preset message sending time slot, a radio wave message is sent to any node, so that the any node records a current time slot when the radio wave message is received according to a local clock, an offset time slot between the any node and the target node is obtained according to the current time slot and the first preset message sending time slot of the target node, and a second preset message sending time slot of the any node in the local clock is updated according to the offset time slot, so that time slots of each node of the Mesh network are aligned. When the current frame is in the first preset message sending time slot, the target node sends a radio wave message to any node, so that the second preset message sending time slot of any node is aligned with the first preset message sending time slot of the target node, all nodes in the Mesh network realize clock alignment, and the technical effect of avoiding mutual conflict of message sending time slots of the nodes is achieved.
Referring to fig. 3, fig. 3 is a block diagram of a first embodiment of a synchronization apparatus for an ad hoc network node according to the present invention, where the apparatus is used for any node in a Mesh network, and any node has a corresponding preset message sending time slot;
the device comprises:
a receiving module 200, configured to receive a radio wave packet sent by a target node, and record a current time slot when the radio wave packet is received according to a local clock;
an obtaining module 400, configured to obtain an offset time slot between the any node and the target node according to the current time slot and a first preset message sending time slot of the target node;
an updating module 600, configured to update a second preset message sending timeslot of the local clock at any node according to the offset timeslot, so as to align timeslots of nodes of the Mesh network.
It should be noted that, in this embodiment, the specific steps performed by the ad hoc network node synchronization apparatus refer to the above description, and are not described herein again.
Referring to fig. 4, fig. 4 is a block diagram of a second embodiment of a self-organizing network node synchronization device according to the present invention, where the device is used for a target node in a Mesh network, and any node in the Mesh network has a corresponding preset message sending timeslot;
the device comprises:
the sending module 100 sends a radio wave packet to any node when a current frame is in a first preset messaging time slot, so that the any node records a current time slot when receiving the radio wave packet according to a local clock, obtains an offset time slot between the any node and the target node according to the current time slot and the first preset messaging time slot of the target node, and updates a second preset messaging time slot of the any node in the local clock according to the offset time slot, so that the time slots of the nodes of the Mesh network are aligned.
It should be noted that, in this embodiment, the specific steps performed by the ad hoc network node synchronization apparatus refer to the above description, and are not described herein again.
In addition, an embodiment of the present invention further provides a computer storage medium, where an ad hoc network node synchronization program is stored on the storage medium, and when executed by a processor, the ad hoc network node synchronization program implements the steps of the ad hoc network node synchronization method according to the foregoing method embodiment. Therefore, a detailed description thereof will be omitted. In addition, the beneficial effects of the same method are not described in detail. For technical details not disclosed in the embodiments of the storage medium referred to in the present application, reference is made to the description of the embodiments of the method of the present application. Determining by way of example, the program instructions may be deployed for execution on one ad hoc network node synchronization device, or on multiple ad hoc network node synchronization devices located at one site, or distributed across multiple sites and interconnected by a communication network.
It will be understood by those skilled in the art that all or part of the processes of the methods of the embodiments described above can be implemented by a computer program, which can be stored in a storage medium and can include the processes of the embodiments of the methods described above when executed. The storage medium may be a magnetic disk, an optical disk, a Read-Only Memory (ROM), a Random Access Memory (RAM), or the like.
The above description is only a preferred embodiment of the present invention, and not intended to limit the scope of the present invention, and all modifications of equivalent structures and equivalent processes, which are made by using the contents of the present specification and the accompanying drawings, or directly or indirectly applied to other related technical fields, are included in the scope of the present invention.
Claims (10)
1. A method for synchronizing ad hoc network nodes is characterized in that the method is used for any node in a Mesh network, and any node has a corresponding preset message sending time slot;
the method comprises the following steps:
receiving a radio wave message sent by a target node, and recording the current time slot when the radio wave message is received according to a local clock;
obtaining an offset time slot between any one node and the target node according to the current time slot and a first preset message sending time slot of the target node;
and updating a second preset message sending time slot of any node in the local clock according to the offset time slot so as to align the time slots of all nodes of the Mesh network.
2. The ad hoc network node synchronization method of claim 1, wherein any one of said nodes has a second node ID;
the step of receiving a radio wave packet sent by a target node and recording a current time slot when the radio wave packet is received according to a local clock includes:
receiving a radio wave message sent by a target node;
analyzing a message header of the radio wave message to obtain first routing information; wherein the first routing information comprises a first node ID;
judging whether the first node ID is consistent with the second node ID;
and if the first node ID is consistent with the second node ID, recording the current time slot when the radio wave message is received according to a local clock.
3. The ad hoc network node synchronization method according to claim 2, wherein the message data of the radio wave packet includes a source IP address and a destination IP address;
after the step of parsing the header of the radio wave packet, the method further includes:
if the message header is a preset value, searching whether the source IP address and the destination IP address exist in a local memory;
and if the source IP address and the destination IP address do not exist in the local memory, storing the radio wave message, and forwarding the radio wave message to at least one node corresponding to a preset multicast address range.
4. The ad hoc network node synchronization method of claim 2, wherein after the step of determining whether the first node ID is consistent with the second node ID, the method further comprises:
and if the first node ID is not consistent with the second node ID, discarding the first radio wave message.
5. The ad hoc network node synchronization method according to claim 1, wherein the step of obtaining an offset time slot between any one node and the target node according to the current time slot and a first preset message time slot of the target node comprises:
and obtaining a difference value between the current time slot and a first preset message sending time slot of the target node according to the current time slot and the first preset message sending time slot, and determining the difference value as an offset time slot between any node and the target node.
6. A method for synchronizing ad hoc network nodes is characterized in that the method is used for a target node in a Mesh network, and any node in the Mesh network has a corresponding preset message sending time slot;
the method comprises the following steps:
when a current frame is in a first preset message sending time slot, sending a radio wave message to any node so that the any node records a current time slot when receiving the radio wave message according to a local clock, obtaining an offset time slot between the any node and the target node according to the current time slot and the first preset message sending time slot of the target node, and updating a second preset message sending time slot of the any node in the local clock according to the offset time slot so that the time slots of all nodes of the Mesh network are aligned.
7. The ad hoc network node synchronization method according to claim 6, wherein the target node stores an ARP address resolution protocol table and a routing table, the ARP table includes a first destination address, the routing table includes first routing information, the first routing information includes a destination node ID;
before the step of sending the radio wave packet to the any node, the method further includes:
obtaining a target destination address of any node;
searching whether a first destination address consistent with the target destination address exists in the ARP table or not; the ARP table further comprises a first node ID corresponding to the first destination address;
if a first destination address consistent with the target destination address exists in the ARP table, acquiring the first node ID;
judging whether the ID of the destination node is consistent with the ID of the first node;
and if the destination node ID is consistent with the first node ID, storing the first routing information into a message header of the radio wave message.
8. The ad hoc network node synchronization method according to claim 6, wherein after the step of determining whether the destination node ID is consistent with the first node ID, the method further comprises:
and if the destination node ID is inconsistent with the first node ID, storing a preset value into a message header of the radio wave message.
9. An ad-hoc network node synchronization apparatus, comprising a memory, a processor and an ad-hoc network node synchronization program stored in the memory and executable on the processor, the ad-hoc network node synchronization program when executed by the processor implementing the steps of the method according to any one of claims 1-7.
10. A computer storage medium storing an ad hoc network node synchronization program which, when executed by a processor, performs the steps of the method of any one of claims 1-7.
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