A virtual backbone network optimization method for flying ad hoc networks
By fully flooding and optimizing the data transmission communication protocol in the flooding stage, building a virtual backbone network and cutting redundant nodes, the problems of network traffic and resource consumption in the flying ad hoc network are solved, and the stability and efficient data transmission of the drone cluster network are achieved.
Patent Information
- Application Number
- CN202410785770.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2024-06-18
- Publication Date
- 2025-10-03
- Estimated Expiration
- 2044-06-18
AI Technical Summary
The flooding protocol in existing flight ad hoc networks leads to increased network traffic and resource consumption, and is prone to forming broadcast storms.
The data transmission communication protocol of the full flooding stage and the optimized flooding stage is adopted to build a virtual backbone network through the key node selection strategy. In the optimized flooding stage, redundant edges and neighbors that repeatedly cover key nodes are trimmed to optimize the selection and number of key nodes.
It improves the network life of drone clusters, maintains link stability, reduces network load and latency, and optimizes network performance.
Smart Images
Figure CN118714584B_ABST
Abstract
Description
Technical Field
[0001] The present application relates to the field of UAV cluster and flying ad hoc network communication technology, and in particular to a virtual backbone network optimization method for flying ad hoc networks. Background Art
[0002] Drone swarms, due to their higher efficiency compared to individual drones, have been widely used in remote sensing, post-disaster search and rescue, and emergency communications. A flying ad hoc network (FAN) is an infrastructure-independent, multi-hop aerial ad hoc network composed of drone swarms, with drone nodes serving as communication nodes. Because wireless communication range is limited by power, nodes in a wireless network cannot communicate directly with all other nodes. Therefore, one or more intermediate nodes are required to forward data from the source to the destination to achieve full network connectivity. While traditional flooding protocols are simple and easy to implement, they still present several challenges. First, flooding protocols can lead to significant redundancy of data packets within the network, increasing network traffic and resource consumption. Second, without any control measures, data packets can propagate indefinitely, overwhelming the network with broadcast data and creating a "broadcast storm." Summary of the Invention
[0003] In view of this, the present invention provides a virtual backbone network optimization method for a flying ad hoc network to solve the problems of increased network traffic and resource consumption caused by data packet redundancy in the network and the easy formation of broadcast storms in existing flooding protocols.
[0004] To this end, the present invention provides the following technical solutions:
[0005] The present invention discloses a virtual backbone network optimization method for a flying ad hoc network. The data transmission communication protocol of the flying ad hoc network is divided into two stages: a full flooding stage and an optimized flooding stage. The method includes the following steps:
[0006] During the full flooding phase, a virtual backbone network is constructed according to a key node selection strategy; the key node selection strategy selects key nodes based on the residual energy of the nodes;
[0007] During the data packet transmission process in the optimized flooding phase, redundant edge key nodes in the virtual backbone network are pruned;
[0008] During the data packet transmission process in the optimized flooding phase, redundant neighbor overlapping key nodes in the virtual backbone network are pruned.
[0009] Furthermore, the packet header in the full flooding phase consists of the following fields:
[0010] origin: the node that initially sends the data packet;
[0011] sender: the node ID of the data packet sender;
[0012] previous-sender: The sender node ID that first received the message;
[0013] seq-num: The unique sequence number of the data packet after it is sent from the source node;
[0014] Flood-indicator: A 1-bit field that indicates whether the packet is a full flooding phase packet or an optimized flooding phase packet.
[0015] Furthermore, during the full flooding phase, a backbone network is constructed based on a key node selection strategy during data packet transmission, including:
[0016] When a node receives a data packet and parses the "flood-indicator" field to identify a full flooding phase message, it forwards the packet in flooding mode.
[0017] During the flooding process, each node will determine whether to mark itself as a key node based on the key node selection strategy;
[0018] The selected key nodes are used as backbone nodes of the virtual backbone network, thereby completing the construction of the virtual backbone network.
[0019] Furthermore, each node will determine whether to mark itself as a key node based on the key node selection strategy, including:
[0020] When a node receives a packet marked as FF, it checks whether the "seq-num" field in the packet is repeated;
[0021] If the message is not repeated, the node will use the "sender" field value in the data packet to overwrite the "previous-sender" field and set the "sender" field value to the current node's NodeID; at the same time, the node will set a timeout timer "ECHO-timer" and resend the data packet;
[0022] If the message is repeated, the node will check whether the "previous-sender" field is its own NodeID; if so, the node will mark itself as a "critical" key node; if there is no data packet that meets this condition within the time specified by the "ECHO-timer", the node will mark itself as a non-critical node.
[0023] Furthermore, the node marks itself as a "critical" node, including:
[0024] During the key node selection process, the backoff window size is modified so that nodes with more residual energy are more likely to become key nodes.
[0025] Furthermore, modify the fallback window size, including:
[0026] according to Modify the size of the fallback window;
[0027] Where CW * is the backoff window size, slot is the unit time slot, γ is the sparsity coefficient, the purpose is to avoid frequent collisions within a certain range when the node's remaining energy is too small; E is the initial energy of the node, E r is the current residual energy of the node, and β is a strict upper bound parameter.
[0028] Furthermore, during the data packet transmission process in the optimized flooding phase, redundant edge key nodes in the virtual backbone network are pruned, including:
[0029] If an edge key node receives a message and finds that there is only one node among its one-hop neighbors and that the node is a key node, the node will set itself as a non-key node.
[0030] Furthermore, during the data packet transmission process in the optimized flooding phase, redundant neighbor overlapping key nodes in the virtual backbone network are trimmed, including:
[0031] If the set of non-critical nodes among the neighboring nodes of the current node is a subset of the set of non-critical nodes among the neighboring nodes of the previous hop node, the node sets itself as a non-critical node.
[0032] Advantages and positive effects of this invention: This invention proposes a new key node selection strategy, ECHO-OPT, which, based on residual energy, ensures that nodes with more residual energy are more likely to become key nodes, thereby improving the network lifespan of the drone cluster and maintaining link stability. Key nodes are optimized and pruned based on neighbor information contained in data packets, reducing the number of key nodes in the cluster while ensuring that key node broadcasts cover the entire cluster. This proposed strategy offers significant advantages in optimizing network load and latency. BRIEF DESCRIPTION OF THE DRAWINGS
[0033] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.
[0034] Figure 1 Flowchart of a virtual backbone network optimization method for a flight ad hoc network according to an embodiment of the present invention;
[0035] Figure 2 is a protocol flow chart in an embodiment of the present invention;
[0036] Figure 3 This is a schematic diagram of edge key node optimization in an embodiment of the present invention;
[0037] Figure 4 Schematic diagram of repeated neighbor key node optimization in an embodiment of the present invention;
[0038] Figure 5 Schematic diagram of the effect of a change in communication distance on the size of a connected dominating set (CDS) in an embodiment of the present invention;
[0039] Figure 6 Schematic diagram of the change in size of the connected dominating set (CDS) under different network densities in an embodiment of the present invention;
[0040] Figure 7 Schematic diagram of network load changes under different network densities in an embodiment of the present invention. DETAILED DESCRIPTION
[0041] In order to enable those skilled in the art to better understand the solutions of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts should fall within the scope of protection of the present invention.
[0042] It should be noted that the terms "first", "second", etc. in the description and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that the numbers used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.
[0043] A virtual backbone network is a logical network structure built on top of a physical network, designed to provide a stable and reliable network backbone for data transmission and routing. The primary goal of a virtual backbone network is to optimize network performance and provide efficient data transmission paths. It can alleviate network congestion, reduce latency, improve bandwidth utilization, and enhance network reliability and stability. Virtual backbone networks are typically constructed by selecting backbone nodes, which typically possess enhanced computing and communication capabilities and more reliable connectivity.
[0044] like Figure 1 As shown, a virtual backbone network optimization method for a flight ad hoc network in an embodiment of the present invention includes the following steps:
[0045] S1,constructs a virtual backbone network based on the key node selection strategy during data packet transmission in the full flooding phase;
[0046] The data transmission communication protocol of the flying ad hoc network is divided into two stages: full flooding (FF) and optimized flooding (OF).
[0047] The FF packet header consists of the following fields:
[0048] origin: The node that originally sent the packet.
[0049] sender: The node ID of the packet sender.
[0050] previous-sender: The ID of the sender node that first received the message (if the sender is the source node, this field is set to 0).
[0051] seq-num: The unique sequence number of the data packet after it is sent from the source node.
[0052] Flood-indicator: A 1-bit field that indicates whether the packet is a full flooding phase packet or an optimized flooding phase packet.
[0053] When a node receives a data packet and detects that the "flood-indicator" field is FF, it forwards the packet in a flooding manner. During the flooding process, each node forwards the packet only once. Furthermore, each node determines whether to mark itself as a key node based on the key node selection policy. These selected key nodes serve as the backbone nodes of the virtual backbone network, completing the construction of the virtual backbone network for drone data transmission.
[0054] When a node receives a packet marked FF, it first checks the "seq-num" field in the packet to see if it is repeated. There are two cases:
[0055] (1) If the message is not repeated, the node will overwrite the "previous-sender" field with the "sender" field value in the data packet and set the "sender" field value to the current node's NodeID. At the same time, the node will set a timeout timer "ECHO-timer" and resend the data packet.
[0056] (2) If the message is repeated, the node checks whether the "previous-sender" field is its own NodeID. If so, the node marks itself as a "critical" node. If no data packet meets this condition within the time specified by the "ECHO-timer", the node marks itself as a non-critical node.
[0057] During the key node selection process, if a node with low energy is selected as a key node, it may cause link interruption during subsequent communication. Taking into account the residual energy of the node, the embodiment of the present invention modifies the function of the backoff window size to make nodes with high residual energy more likely to become key nodes. Specifically, the embodiment of the present invention proposes the following function to adjust the backoff window size:
[0058]
[0059] In the formula, slot is the unit time slot, γ is the sparsity coefficient, the purpose is to avoid frequent collisions within a certain range when the node residual energy is too small. E is the initial energy of the node, E r is the node's current remaining energy, and β is a strict upper bound parameter, intended to keep the backoff window size within a certain range. Since all drones have the same initial energy, nodes with more remaining energy will have smaller contention windows, enabling them to receive channel replies more quickly and become key nodes, thus maintaining cluster stability.
[0060] S2. Optimizing redundant edge key nodes in the virtual backbone network during data packet transmission in the optimized flooding phase;
[0061] Edge key node: If a node receives a message and finds that there is only one node among its one-hop neighbors and that the node is a key node, the node will set itself as a non-key node.
[0062] S3, during the data packet transmission process of the optimized flooding phase, optimizing the redundant neighbor duplication coverage of key nodes in the virtual backbone network;
[0063] Neighbor over-coverage: If the set of non-critical nodes among the neighbor nodes of the current node is a subset of the set of non-critical nodes among the neighbor nodes of the previous-hop node, then the node sets itself as a non-critical node.
[0064] In the OF phase, optimize the edge critical nodes and neighbor repeated-coverage critical nodes to reduce the communication load.
[0065] Let CX be the total number of bytes transmitted through the network per second, N represent the number of nodes, and L represent the payload size (in bytes). Assume that each node generates broadcast traffic periodically at a rate of R Gen packets per second.
[0066] The communication complexity of this protocol after optimizing and pruning redundant nodes in the OF phase is as follows:
[0067] R ff N(L + l4) + R ff N(N Critical + 1)(L + l4) + (R Gen - R ff )N(N Trim + 1)(L + l);
[0068] Where N Critical is the number of critical nodes in the network, N Trim is the number of optimized critical nodes, and R gen > R ff N Critical > N trim .
[0069] Subsequently, analyze the communication complexity gain between the existing protocol and this protocol:
[0070]
[0071] Where N Trim < N Critical < N, then the communication complexity gain is negatively correlated with N Critical and N trim .
[0072]
[0073] Where R Hello is the message sending time interval, and N Neigh represents the single-hop neighbors of the node. It can be seen that the communication complexity gain is positively correlated with R Hello and N Neigh .
[0074]
[0075] Because NTrim <N Critical <N and R ff <R Gen , so It can be seen that the communication complexity gain is negatively correlated with the difference between N Trim and N Critical .
[0076] Since R ff , R Gen , L, and l i in the formula are all constant terms, the communication complexity of this protocol can be simplified as:
[0077] CX ECHO-OPT =(L + l4)N[R ff (N Critical - N trim + 1)+ R Gen (N Trim + 1)];
[0078] In the formula, N[[ID=
[41] Trim > N Critical - N Trim , then the asymptotic complexity of ECHO - OPT is O(NN Trim ).
[0079] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present invention.
Claims
1. A virtual backbone network optimization method for a flying ad hoc network, characterized in that: The data transmission communication protocol of the flight ad hoc network is divided into two stages: full flooding stage and optimized flooding stage, including the following steps: During the full flooding phase, a virtual backbone network is constructed according to a key node selection strategy; the key node selection strategy selects key nodes based on the residual energy of the nodes; During the data packet transmission process in the optimized flooding phase, redundant edge key nodes in the virtual backbone network are pruned; During the data packet transmission process of the optimized flooding phase, redundant neighbor overlapping key nodes in the virtual backbone network are pruned; Each node will determine whether to mark itself as a key node based on the key node selection strategy, including: When a node receives a packet marked as FF, it checks whether the "seq-num" field in the packet is repeated; If the message is not repeated, the node will use the "sender" field value in the data packet to overwrite the "previous-sender" field and set the "sender" field value to the current node's NodeID; at the same time, the node will set a timeout timer "ECHO-timer" and resend the data packet; If the message is repeated, the node will check whether the "previous-sender" field is its own NodeID; if so, the node will mark itself as a "critical" key node; if there is no data packet that meets this condition within the time specified by the "ECHO-timer", the node will mark itself as a non-critical node.
2. The virtual backbone network optimization method of a flight ad hoc network according to claim 1, characterized in that: The packet header in the full flooding phase consists of the following fields: origin: the node that initially sends the data packet; sender: the node ID of the packet sender; previous-sender: The sender node ID that first received the message; seq-num: The unique sequence number of the data packet after it is sent from the source node; flood-indicator: A 1-bit field that indicates whether the packet is a full flooding phase packet or an optimized flooding phase packet.
3. The virtual backbone network optimization method of a flight ad hoc network according to claim 2, characterized in that: During the full flooding phase, a backbone network is constructed based on the key node selection strategy during data packet transmission, including: When a node receives a data packet and parses the "flood-indicator" field to identify a full flooding phase message, it forwards the packet in flooding mode. During the flooding process, each node will determine whether to mark itself as a key node based on the key node selection strategy; The selected key nodes are used as backbone nodes of the virtual backbone network, thereby completing the construction of the virtual backbone network.
4. The virtual backbone network optimization method of a flight ad hoc network according to claim 3, characterized in that: A node marks itself as "critical", including: During the key node selection process, the backoff window size is modified so that nodes with more residual energy are more likely to become key nodes.
5. The virtual backbone network optimization method of a flight ad hoc network according to claim 4, characterized in that: Modify the fallback window size, including: according to Modify the size of the fallback window; Where, is the fallback window size, is the unit time slot, is the sparse coefficient, which aims to avoid frequent collisions within a certain range when the node's remaining energy is too small; is the initial energy of the node, is the current remaining energy of the node, is a strict upper bound parameter.
6. The virtual backbone network optimization method of a flight ad hoc network according to claim 3, characterized in that: During the data packet transmission process in the optimized flooding phase, redundant edge key nodes in the virtual backbone network are pruned, including: If an edge key node receives a message and finds that there is only one node among its one-hop neighbors and that the node is a key node, the node will set itself as a non-key node.
7. The virtual backbone network optimization method of a flight ad hoc network according to claim 3, characterized in that: During the data packet transmission process in the optimized flooding phase, redundant neighbor overlapping key nodes in the virtual backbone network are trimmed, including: If the set of non-critical nodes among the neighboring nodes of the current node is a subset of the set of non-critical nodes among the neighboring nodes of the previous hop node, the node sets itself as a non-critical node.