A source node triggered forwarder identification advertisement opportunity routing candidate coordination method

Abstract

The application discloses a source node triggered forwarder identification announcement opportunity routing candidate coordination method, and belongs to the technical field of wireless communication. A source node constructs a candidate relay set from one-hop neighbors and performs priority sorting; the source node sends a to-be-forwarded data packet, and a candidate relay temporarily stores after receiving the data packet, and sends an acknowledgement message to the source node when a waiting time carried in the data packet expires; the source node determines an actual forwarding node according to the acknowledgement message within a preset acknowledgement window, sends forwarder identification announcement information to the candidate relay set, and the rest of the candidate relays except the actual forwarding node cancel forwarding according to the information. The method announces the actual forwarding node identification by the source node, cooperates with the waiting time parameter design and the time slot length configuration, suppresses the redundant transmission of the non-actual forwarding candidate relay, and reduces the candidate coordination overhead. The application is suitable for high-dynamic, time-delay-sensitive low-altitude unmanned aerial vehicle network communication scenes, such as emergency communication and disaster monitoring and the like.

Description

Technical Field

[0001] This invention belongs to the field of wireless communication technology, and particularly relates to a method for coordinating route candidate coordination based on the forwarder identifier announcement opportunity triggered by the source node. Background Technology

[0002] In recent years, low-altitude unmanned aerial vehicle (UAV) networks have been widely used in emergency rescue, disaster monitoring, and other mission scenarios, placing higher demands on the time sensitivity, reliability, and dynamic adaptability of communication networks. However, due to frequent changes in network topology and link instability, traditional routing mechanisms relying on fixed paths are difficult to adapt to the real-time transmission needs of mission data. Against this backdrop, opportunistic routing improves the robustness of data forwarding by introducing a set of candidate relays and leveraging their diversity. However, the coordination of candidate relays has become a key bottleneck: in densely deployed low-altitude networks, the reachability of candidate relays is enhanced. If low-priority relays cannot promptly identify the actual forwarder, duplicate forwarding can easily occur, thereby increasing data transmission overhead and pushing up end-to-end latency.

[0003] Among existing candidate relay coordination methods, timer-based schemes are widely used due to their distributed and easily deployable nature and low control signaling overhead. These schemes suppress redundant forwarding by setting priority-related waiting times and listening for acknowledgments from the actual forwarder via a single hop. However, limited by the single-hop listening range, some candidate relays still cannot promptly obtain the actual forwarder, resulting in redundancy. If multi-hop extended listening is used, it introduces excessively high coordination overhead, and the reliability of acknowledgment delivery decreases with the number of hops, making it difficult to simultaneously achieve redundancy suppression and low coordination latency.

[0004] Therefore, there is an urgent need to study a time-sensitive and efficient opportunistic routing candidate coordination method for highly dynamic low-altitude UAV networks, which can effectively coordinate the forwarding of candidate relays and suppress redundant data transmission within a limited time window. Summary of the Invention

[0005] To address the problems existing in the prior art, the purpose of this invention is to provide a time-sensitive and efficient opportunity routing candidate coordination scheme adapted to highly dynamic low-altitude UAV networks. On one hand, it enables consistent forwarding decisions among candidate relays, allowing non-actual forwarding nodes to promptly cancel forwarding operations on the same data packet, thereby effectively suppressing duplicate forwarding. On the other hand, it enables time-sequential control of the acknowledgment and forwarding coordination process of candidate relays while satisfying link propagation and processing delay constraints, and rationally configures the time slot length to avoid acknowledgment collisions and coordination conflicts caused by premature responses from candidate relays, thereby optimizing coordination delay. Therefore, the method proposed in this invention can achieve effective coordination of candidate relay forwarding behavior without significantly increasing control overhead, balancing redundancy suppression and coordination delay optimization.

[0006] The objective of this invention is achieved through the following technical solution: a source node-triggered forwarder identifier announcement opportunity routing candidate coordination method, comprising the following steps:

[0007] Step S1: The source node obtains its one-hop neighbor node information, constructs a candidate relay set for forwarding the same data packet, and sorts the candidate relay set by priority.

[0008] Step S2: The source node sends the data packet to be forwarded to the candidate relay set. After receiving the data packet, each candidate relay temporarily stores the data packet and enters the candidate coordination waiting state. When the corresponding waiting time condition is met and no indication information for suppressing forwarding is received, the candidate relay sends an acknowledgment message to the source node.

[0009] Step S3: After receiving the confirmation message within the preset confirmation window of the candidate coordination, the source node determines the actual forwarding node according to the confirmation message and sends forwarder identifier announcement information containing the identifier of the actual forwarding node and the identifier of the data packet to the candidate relay set;

[0010] Step S4: The actual forwarding node performs forwarding of the data packet, and the remaining candidate relays cancel the forwarding operation of the data packet after receiving the forwarder identifier announcement information.

[0011] Furthermore, the priority is measured by a metric parameter, which includes at least one of the following: distance from the node to the destination node, link quality, remaining node resources, forwarding cost, or forwarding reliability.

[0012] Furthermore, the confirmation message includes at least the identification information of the data packet and the identification information of the candidate relay that sent the confirmation message;

[0013] The waiting time for a candidate relay with a high forwarding priority is no greater than the waiting time for a candidate relay with a low forwarding priority; the waiting time is timed in discrete time slots.

[0014] The waiting time is determined by a waiting function, which satisfies the following relationship:

[0015] ;

[0016] in, The waiting time is the waiting time corresponding to the candidate relay with priority i, where i is the priority number of the candidate relay in the candidate relay set; Priority wait offset factor, n is the number of nodes in the candidate relay set; Based on the base duration, To protect the duration.

[0017] Furthermore, the source node identifies the candidate relay corresponding to the first acknowledgment message it receives as the actual forwarding node;

[0018] The confirmation message is sent via a separate control frame;

[0019] The forwarder identifier notification information is sent through a separate control frame, or carried as a field in subsequent control frames or subsequent data frames.

[0020] Furthermore, step S4 includes the following sub-steps:

[0021] Step S4.1: After being identified as the actual forwarding node, the actual forwarding node performs the forwarding operation on the data packet and sends the data packet to the next hop node or the destination node;

[0022] Step S4.2: When any of the following conditions are met, the remaining candidate relays shall cancel the forwarding operation of the data packet and discard the temporarily stored data packet: receive the forwarder identifier announcement information; detect the indication information that the high priority node has completed forwarding; receive the cancellation forwarding instruction / indication information for suppressing forwarding.

[0023] Furthermore, the reference duration satisfy:

[0024] ;

[0025] Where t0 is the duration of the confirmation sub-slot and t1 is the duration of the notification sub-slot;

[0026] Protection duration satisfy:

[0027] ;

[0028] Where s is the source node, V is the distance from the source node s to the node u. s For signal propagation speed, node i V represents the candidate relay with forwarding priority i in the candidate relay set; b For link data rate, DataPacket size The size of the data packet.

[0029] Furthermore, the candidate coordination corresponding to steps S2 and S3 adopts a time-domain frame structure of a coordination superframe. The coordination superframe is initiated after the source node completes the data packet transmission and includes at least a plurality of sequential time slots arranged in order of candidate relay priority. n is the number of nodes in the candidate relay set; each time slot This corresponds to a forwarding coordination opportunity for a candidate relay;

[0030] Except for the last time slot In addition, each time slot This includes: an acknowledgment sub-slot t0 for the candidate relay to send the acknowledgment message, and an announcement sub-slot t1 for the source node to send the forwarder identifier announcement information, and satisfies the following conditions: In this context, after receiving the confirmation message in the confirmation sub-slot t0, the source node sends the forwarder identifier announcement information in the corresponding announcement sub-slot t1;

[0031] Last time slot Only the confirmation sub-slot t0 is included; the source node does not send the forwarder identifier announcement information.

[0032] The timing configuration of the confirmation sub-slot t0 and the announcement sub-slot t1 satisfies the following constraint: for any adjacent forwarding priority candidate relay pair ,have:

[0033] ;

[0034] ;

[0035] Among them, ACK size The length of the confirmation message, NodeID size The length of the notification message is defined by the identifier of the forwarder. This represents the propagation delay from candidate relay with priority i to candidate relay with priority i+1. This represents the propagation delay from the candidate relay with priority i to the source node s. This represents the propagation delay from the source node s to the candidate relay with priority i+1.

[0036] The beneficial effects of this invention are as follows: Based on the forwarder identification information announcement and time slot constraint coordination mechanism, combined with priority waiting time design, this invention proposes a source node-triggered forwarder identification announcement opportunistic route candidate coordination method, which solves the problem that it is difficult to simultaneously take into account redundancy suppression and low coordination latency in the forwarding coordination process of opportunistic route candidate relay, reduces redundant transmission and coordination overhead, and improves the time sensitivity and reliability of low-altitude UAV network data transmission. Attached Figure Description

[0037] Figure 1 This is a flowchart of the method of the present invention;

[0038] Figure 2 This is a schematic diagram of the coordinated superframe (frame structure) in this embodiment;

[0039] Figure 3 This is a timing diagram of the candidate relay waiting time in this embodiment. Detailed Implementation

[0040] The technical solution of the present invention will be further described below with reference to the accompanying drawings.

[0041] like Figure 1 As shown, a source node-triggered forwarder identifier announcement opportunity route candidate coordination method of the present invention includes the following steps:

[0042] Step S1: Candidate Construction. The source node obtains its one-hop neighbor node information, constructs a candidate relay set for forwarding the same data packet, and prioritizes the candidate relay set; including the following sub-steps:

[0043] Step S1.1: The source node selects nodes that meet the preset forwarding conditions from its one-hop neighbor nodes to construct a candidate relay set for forwarding the same data packet;

[0044] Step S1.2: The source node sorts the candidate relays in the candidate relay set according to the preset forwarding priority metric;

[0045] The preset forwarding conditions include at least one metric parameter used to characterize the forwarding priority of candidate relays; optionally, they also include at least one constraint condition used to guarantee reachability or link availability.

[0046] The metric parameters include at least one of the following: distance from the node to the destination node, link quality, remaining node resources, forwarding cost, or forwarding reliability.

[0047] Step S2: Confirm Coordination. The source node sends the data packet to be forwarded to the candidate relay set. After receiving the data packet, each candidate relay temporarily stores the data packet and enters the candidate coordination waiting state. When the corresponding waiting time condition is met and no indication information for suppressing forwarding is received, the candidate relay sends a confirmation message to the source node.

[0048] The confirmation message includes at least the identification information of the data packet and the identification information of the candidate relay that sent the confirmation message;

[0049] The holding time of a candidate relay is related to its forwarding priority, ensuring that the holding time of a candidate relay with a higher forwarding priority is no greater than the holding time of a candidate relay with a lower forwarding priority; the holding time is timed in discrete time slots.

[0050] The waiting time is determined by a waiting function, which satisfies the following relationship:

[0051] Equation (1)

[0052] in, The waiting time is the waiting time for the candidate relay with priority i, where i is the priority number of the candidate relay in the candidate relay set. The smaller i is, the higher the priority. Priority wait offset factor, n is the number of nodes in the candidate relay set; Based on the base duration, To protect the duration.

[0053] Base duration satisfy:

[0054] Equation (2)

[0055] Where t0 is the duration of the confirmation sub-slot and t1 is the duration of the notification sub-slot;

[0056] Protection duration satisfy:

[0057] Equation (3)

[0058] Where s is the source node, V is the distance from the source node s to the node u. s For signal propagation speed, node i V represents the candidate relay with forwarding priority i in the candidate relay set; b For link data rate, DataPacket size The size of the data packet.

[0059] Step S3: Forwarder Announcement. After receiving the confirmation message within the preset confirmation window of the candidate coordination, the source node determines the actual forwarding node based on the confirmation message and sends a forwarder identifier announcement message containing the identifier of the actual forwarding node and the identifier of the data packet to the candidate relay set;

[0060] Furthermore, the source node identifies the candidate relay corresponding to the first acknowledgment message it receives as the actual forwarding node;

[0061] The confirmation message is sent via a separate control frame; the forwarder identifier notification information is sent via a separate control frame, or carried as a field in subsequent control frames or subsequent data frames.

[0062] The forwarder identification notification information is sent via unicast, broadcast, or multicast.

[0063] The candidate coordination corresponding to steps S2 and S3 adopts a time-domain frame structure of a coordination superframe. The coordination superframe is initiated after the source node completes the transmission of the data packet and includes at least a plurality of sequential time slots arranged in order of candidate relay priority. n is the number of nodes in the candidate relay set; each time slot This corresponds to a forwarding coordination opportunity for a candidate relay;

[0064] Except for the last time slot In addition, each time slot This includes: an acknowledgment sub-slot t0 for the candidate relay to send the acknowledgment message, and an announcement sub-slot t1 for the source node to send the forwarder identifier announcement information, and satisfies the following conditions: In this context, after receiving the confirmation message in the confirmation sub-slot t0, the source node sends the forwarder identifier announcement information in the corresponding announcement sub-slot t1;

[0065] Last time slot Only the confirmation sub-slot t0 is included; the source node does not send the forwarder identifier announcement information.

[0066] To ensure the effectiveness of suppression between adjacent priority candidate relays, the timing configuration of the confirmation sub-slot t0 and the announcement sub-slot t1 satisfies the following constraint: for any adjacent forwarding priority candidate relay pair... ,have:

[0067] Equation (4)

[0068] Equation (5)

[0069] Among them, ACK size The length of the confirmation message, NodeID size The length of the notification message is defined by the identifier of the forwarder. The single-hop propagation delay from node u to node v is represented by: This represents the propagation delay from candidate relay with priority i to candidate relay with priority i+1. This represents the propagation delay from the candidate relay with priority i to the source node s. This represents the propagation delay from the source node s to the candidate relay with priority i+1.

[0070] Step S4: Forwarding and Cancellation. The actual forwarding node forwards the data packet, and the remaining candidate relays cancel the forwarding operation of the data packet after receiving the forwarder identifier announcement information;

[0071] Includes the following sub-steps:

[0072] Step S4.1: After being identified as the actual forwarding node, the actual forwarding node performs the forwarding operation on the data packet and sends the data packet to the next hop node or the destination node;

[0073] Step S4.2: When any of the following conditions are met, the remaining candidate relays shall cancel the forwarding operation of the data packet and discard the temporarily stored data packet: receive the forwarder identifier announcement information; detect the indication information that the high priority node has completed forwarding; receive the cancellation forwarding instruction / indication information for suppressing forwarding.

[0074] The following example illustrates that source node s needs to forward data packet P to destination node M. k Taking an example, the method of the present invention will be fully described. Both the source node s and the destination node M are wireless communication nodes, which may include unmanned aerial vehicle platforms, ground communication terminals, or other devices with wireless communication capabilities. Let the candidate relay set obtained after filtering and sorting by the source node s be . To simplify implementation and facilitate explanation, in this embodiment, the preset forwarding priority metric is selected as the candidate relay node. i Distance to destination node M This distance can be calculated from the node's Global Navigation Satellite System (GNSS) coordinates or cooperative positioning results, and its priority satisfies... ,Right now .

[0075] Source node s generates data packet P k The packet header includes the packet identifier (PacketID) and the candidate relay set. Information, timing parameters (including candidate relay priority information, confirmation sub-time slot t0, announcement sub-time slot t1, link data rate V) b Signal propagation speed V s Data Packet Size size Then, the data packet is broadcast to the candidate relay set C. Upon receiving the data packet, candidate relays node1, node2, and node3 buffer it and enter a candidate coordination state.

[0076] Each candidate relay calculates its corresponding waiting time based on its own forwarding priority and the timing parameters carried in the data packet: , , The waiting time satisfies the following conditions:

[0077] Equation (6)

[0078] Base duration and Figure 2The coordinated superframe structure shown corresponds to: taking i=1 For i=2,3, take:

[0079] Equation (7)

[0080] Protection duration Used to compensate for the time required for data packet propagation and reception, the specific candidate relay waiting time timing is as follows: Figure 3 As shown.

[0081] To ensure the effectiveness of suppression between adjacent priority candidate relays (i.e., node) i+1 (If the suppression information is received before its waiting time expires and the message is not repeatedly forwarded), for any adjacent forwarding priority candidate relay pair Regarding waiting time The range of values ​​forms a constraint, ensuring that before a candidate relay with priority i enters its confirmation sub-slot t0, the set The candidate relays within the system can complete the transmission and reception of data packets, thereby avoiding coordination failures where "high-priority candidate relays acknowledge too early while low-priority candidate relays have not yet completed reception".

[0082] Equation (5) further gives the value for the unit time slot. By substituting equations (6) and (7) into equation (5) under the constraints, we obtain:

[0083] Equation (8)

[0084] in, The expression for the total delay experienced by the candidate relay with priority i from completion of confirmation and notification via source node s to the candidate relay with priority i+1 is as follows:

[0085] Equation (9)

[0086] The unit time slot can be obtained by rearranging formula (8). Lower bound of length:

[0087] Equation (10)

[0088] Depend on As defined, for any adjacent forwarding priority candidate relay pair All have ,thereby

[0089] Equation (11)

[0090] Further obtain

[0091] Equation (12)

[0092] To ensure that this constraint holds for all adjacent candidate relay pairs, we have:

[0093] Equation (13)

[0094] in, To provide a protection margin, it is used to satisfy strict inequalities and compensate for clock skew, node processing delay, transmit / receive switching delay, and air interface protection interval.

[0095] Therefore, the source node can calculate the length of the unit time slot based on the network size, the maximum geometric distance between the candidate relay and the source node, and the link rate. (In this embodiment, it is possible to take...) In other implementations, t0 and t1 can also be set according to the length of the acknowledgment message, the length of the announcement message, the propagation delay, and the processing delay, as long as the constraints given in equation (13) are met. t0 and t1 are then carried as timing parameters in the data packet, allowing each candidate relay to calculate its waiting time accordingly and communicate with the data packet. Figure 2 , Figure 3 The temporal structures shown are strictly aligned.

[0096] If node1 does not receive the indication message for suppressing forwarding before its waiting time expires, then Figure 2 Within the acknowledgment sub-slot t0 of time slot T1, the source node s sends an acknowledgment message ACK_1. ACK_1 includes: PacketID and node_1, the node identifier of node1. After receiving ACK_1 within the acknowledgment sub-slot t0 of T1, the source node s identifies node1 as the actual forwarding node and sends forwarder identifier announcement information (which can be denoted as Notify_1) to the candidate relay set within the announcement sub-slot t1 of T1. The announcement information includes: ForwarderID = node_1 and PacketID.

[0097] After receiving the forwarder identifier notification information Notify_1 before their respective waiting time expires, candidate relay nodes node2 and node3 identify the actual forwarding node as node1 and revoke the forwarding of data packet P. k The forwarding operation discards locally cached copies of the data packets. Optionally, forwarding can be prematurely cancelled if the candidate relay can detect the acknowledgment message ACK_1 of a higher-priority candidate relay. Subsequently, the actual forwarding node node1 executes the forwarding operation on data packet P. k The forwarding of the data is then sent to the next hop node or the destination node M.

[0098] If source node s does not receive an acknowledgment message from node 1 within the acknowledgment sub-slot t0 of time slot T1, it continues to listen for the acknowledgment sub-slot t0 of the next time slot T2. If node 2 meets the sending condition when its waiting time expires, it sends an acknowledgment message ACK_2 within the acknowledgment sub-slot t0 of T2. ACK_2 includes: PacketID and node 2's node identifier node_2. After receiving ACK_2 within the acknowledgment sub-slot t0 of T2, source node s identifies node 2 as the actual forwarding node and sends a forwarder identifier announcement message (which can be denoted as Notify_2) containing ForwarderID= node_2 within the announcement sub-slot t1 of T2 to suppress repeated forwarding by subsequent priority candidate relays.

[0099] After receiving the forwarder identifier notification information Notify_2 before its waiting time expires, candidate relay node3 identifies the actual forwarding node as node2 and withdraws its support for data packet P. k The forwarding operation discards locally cached copies of the data packets. Optionally, forwarding can be prematurely cancelled if the candidate relay can detect the acknowledgment message ACK_2 of a higher-priority candidate relay. Subsequently, the actual forwarding node node2 executes the forwarding operation on data packet P. k The forwarding of the data is then sent to the next hop node or the destination node M.

[0100] If source node s does not receive an acknowledgment message within the acknowledgment sub-slots t0 of T1 and T2, but receives an acknowledgment message ACK_3 from node3 within the acknowledgment sub-slot t0 of the last time slot T3, then source node s can identify node3 as the actual forwarding node. Since T3 is the last time slot, there are no lower-priority candidate relays after it. Therefore, source node s does not need to send the forwarder identifier announcement information corresponding to the announcement sub-slot t1. node3 can then execute packet P after completing the acknowledgment message transmission. k Forwarded.

[0101] If the source node s does not receive any acknowledgment message from any candidate relay during the entire coordination superframe, it indicates that there is no suitable actual forwarder within the current candidate coordination period. In an alternative implementation, the source node s may retransmit data packet P. k In another alternative implementation, the source node s can reacquire its one-hop neighbor information and update the candidate relay set.

[0102] Through the above embodiments, the source node explicitly announces the actual forwarder identifier during the candidate coordination phase, enabling low-priority candidate relays to obtain suppression information and cancel forwarding in a timely manner before forwarding, thereby reducing the probability of repeated forwarding and reducing channel occupation and coordination overhead. Simultaneously, by designing the waiting time parameter and configuring the time slot length, the confirmation and forwarding coordination process of candidate relays is controlled in a time-sequential manner. Under the condition of satisfying the link propagation and processing delay constraints, confirmation conflicts and coordination failures are avoided, thereby improving the time sensitivity and reliability of the candidate coordination mechanism.

[0103] It is understood that the present invention has been described through some embodiments, and those skilled in the art will recognize that various changes or equivalent substitutions can be made to these features and embodiments without departing from the spirit and scope of the invention. Furthermore, under the teachings of the present invention, these features and embodiments can be modified to adapt to specific situations and materials without departing from the spirit and scope of the invention. Therefore, the present invention is not limited to the specific embodiments disclosed herein, and all embodiments falling within the scope of the claims of this application are within the protection scope of the present invention.

Claims

1. A method for coordinating route candidate coordination based on the forwarder identifier announcement triggered by a source node, characterized in that, Includes the following steps: Step S1: The source node obtains its one-hop neighbor node information, constructs a candidate relay set for forwarding the same data packet, and sorts the candidate relay set by priority. Step S2: The source node sends the data packet to be forwarded to the candidate relay set. After receiving the data packet, each candidate relay temporarily stores the data packet and enters the candidate coordination waiting state. When the corresponding waiting time condition is met and no indication information for suppressing forwarding is received, the candidate relay sends an acknowledgment message to the source node. Step S3: After receiving the confirmation message within the preset confirmation window of the candidate coordination, the source node determines the actual forwarding node according to the confirmation message and sends forwarder identifier announcement information containing the identifier of the actual forwarding node and the identifier of the data packet to the candidate relay set; Step S4: The actual forwarding node performs forwarding of the data packet, and the remaining candidate relays cancel the forwarding operation of the data packet after receiving the forwarder identifier announcement information.

2. The source node-triggered forwarder identifier announcement opportunity route candidate coordination method according to claim 1, characterized in that, The priority is measured by metrics, which include at least one of the following: distance from the node to the destination node, link quality, remaining node resources, forwarding cost, or forwarding reliability.

3. The source node-triggered forwarder identifier announcement opportunity route candidate coordination method according to claim 2, characterized in that, The confirmation message includes at least the identification information of the data packet and the identification information of the candidate relay that sent the confirmation message; The waiting time for a candidate relay with a high forwarding priority is no greater than the waiting time for a candidate relay with a low forwarding priority; the waiting time is timed in discrete time slots. The waiting time is determined by a waiting function, which satisfies the following relationship: ； in, The waiting time is the waiting time corresponding to the candidate relay with priority i, where i is the priority number of the candidate relay in the candidate relay set; Priority wait offset factor, n is the number of nodes in the candidate relay set; Based on the base duration, To protect the duration.

4. The source node-triggered forwarder identifier announcement opportunity route candidate coordination method according to claim 3, characterized in that, The source node identifies the candidate relay corresponding to the first acknowledgment message it receives as the actual forwarding node; The confirmation message is sent via a separate control frame; The forwarder identifier notification information is sent through a separate control frame, or carried as a field in subsequent control frames or subsequent data frames.

5. The source node-triggered forwarder identifier announcement opportunity route candidate coordination method according to claim 4, characterized in that, Step S4 includes the following sub-steps: Step S4.1: After being identified as the actual forwarding node, the actual forwarding node performs the forwarding operation on the data packet and sends the data packet to the next hop node or the destination node; Step S4.2: When any of the following conditions are met, the remaining candidate relays shall cancel the forwarding operation of the data packet and discard the temporarily stored data packet: receive the forwarder identifier announcement information; detect the indication information that the high priority node has completed forwarding; receive the cancellation forwarding instruction / indication information for suppressing forwarding.

6. The source node-triggered forwarder identifier announcement opportunity route candidate coordination method according to claim 5, characterized in that, The reference duration satisfy: ； Where t0 is the duration of the confirmation sub-slot and t1 is the duration of the notification sub-slot; Protection duration satisfy: ； Where s is the source node, V is the distance from the source node s to the node u. s For signal propagation speed, node i V represents the candidate relay with forwarding priority i in the candidate relay set; b For link data rate, DataPacket size The size of the data packet.

7. The source node-triggered forwarder identifier announcement opportunity route candidate coordination method according to claim 6, characterized in that, The candidate coordination corresponding to steps S2 and S3 adopts a time-domain frame structure of a coordination superframe. The coordination superframe is initiated after the source node completes the transmission of the data packet and includes at least a plurality of sequential time slots arranged in order of candidate relay priority. n is the number of nodes in the candidate relay set; each time slot This corresponds to a forwarding coordination opportunity for a candidate relay; Except for the last time slot In addition, each time slot This includes: an acknowledgment sub-slot t0 for the candidate relay to send the acknowledgment message, and an announcement sub-slot t1 for the source node to send the forwarder identifier announcement information, and satisfies the following conditions: In this context, after receiving the confirmation message in the confirmation sub-slot t0, the source node sends the forwarder identifier announcement information in the corresponding announcement sub-slot t1; Last time slot Only the confirmation sub-slot t0 is included; the source node does not send the forwarder identifier announcement information. The timing configuration of the confirmation sub-slot t0 and the announcement sub-slot t1 satisfies the following constraint: for any adjacent forwarding priority candidate relay pair ,have: ； ； Among them, ACK size The length of the confirmation message, NodeID size The length of the notification message is defined by the identifier of the forwarder. This represents the propagation delay from candidate relay with priority i to candidate relay with priority i+1. This represents the propagation delay from the candidate relay with priority i to the source node s. This represents the propagation delay from the source node s to the candidate relay with priority i+1.

8. The source node-triggered forwarder identifier announcement opportunity route candidate coordination method according to claim 7, characterized in that, The priority metric also includes at least one constraint to guarantee reachability or link availability.

9. The source node-triggered forwarder identifier announcement opportunity route candidate coordination method according to claim 8, characterized in that, The specific steps of S1 are as follows: Step S1.1: The source node selects nodes that meet the preset forwarding conditions from its one-hop neighbor nodes to construct a candidate relay set for forwarding the same data packet; the preset forwarding conditions include at least one metric parameter used to characterize the forwarding priority of the candidate relays. Step S1.2: The source node sorts the candidate relays in the candidate relay set according to the preset forwarding priority metric.

10. The source node-triggered forwarder identifier announcement opportunity route candidate coordination method according to claim 9, characterized in that, The forwarder identification notification information is sent via unicast, broadcast, or multicast.

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