A multi-aircraft cooperative ad hoc network communication method for an aerial search and rescue task

Abstract

The application provides a multi-aircraft cooperative ad hoc network communication method for an aerial search and rescue task, and belongs to the technical field of aerial search and rescue communication. The method comprises the following steps: configuring an ad hoc network communication system by using a time division multiple access networking protocol to obtain a configured ad hoc network communication system; and performing resource scheduling and distribution on multiple aerial search and rescue tasks by using the configured ad hoc network communication system. The application can significantly improve the time slot utilization rate and multi-task parallel execution capability in the multi-aircraft cooperative communication process.

Description

Technical Field

[0001] This application relates to the field of aviation search and rescue communication technology, and in particular to a multi-aircraft cooperative ad hoc network communication method for aviation search and rescue missions. Background Technology

[0002] Air search and rescue missions are characterized by high dynamism, wide coverage, and multiple nodes, placing stringent demands on the resilience, coverage, and networking flexibility of communication systems. With the continuous development of informatization and networking, modern air search and rescue missions face increasingly complex electromagnetic environments and the need for multi-node collaboration. Mobile Ad Hoc Networks (MANETs), due to their decentralized, self-organizing, and highly resilient characteristics, are considered one of the important communication methods for handling air search and rescue missions.

[0003] Currently, aviation search and rescue communication systems mainly employ several traditional ad hoc network protocols: The first type is a hybrid routing method for aviation ad hoc networks, which uses table-driven routing within the formation to ensure real-time performance and on-demand routing between formations to adapt to topology changes caused by high-speed movement; the second type is an optical system based on laser omnidirectional communication, which addresses the distributed system problem of formations in denied environments by carrying laser communication payloads; the third type is a heterogeneous network fusion solution in the field of emergency communication, which integrates various networks such as Professional Digital Trunking (PDT), satellite, scattering, and ad hoc networks to improve network construction speed and link concurrency capabilities in emergency scenarios; the fourth type is the use of wireless ad hoc network technology in civil aviation emergency communication, which achieves multi-hop relay interconnection through different forms of equipment such as vehicle-mounted, handheld, and emergency communication boxes to expand network coverage.

[0004] However, the aforementioned traditional aviation search and rescue ad hoc network communication methods have the following drawbacks in practical applications:

[0005] First, it is difficult to support large-scale, high-density node collaborative operations. Most existing communication protocols only support collaborative work with a small number of nodes, mainly designed for single-aircraft or small-scale formations. When the number of nodes increases dramatically, the control overhead of routing protocols increases dramatically, leading to a sharp decline in network performance and even frequent routing failures, which cannot meet the needs of large-scale multi-aircraft collaborative aerial search and rescue missions.

[0006] Secondly, complex electromagnetic environments present problems such as long network establishment delays and low resource utilization. Existing solutions suffer from long network establishment times and slow new node integration and path reconstruction speeds when facing complex electromagnetic environments and low signal-to-noise ratio backgrounds.

[0007] Finally, the system suffers from poor reliability and a lack of effective multi-machine collaboration mechanisms. Most existing technologies rely on single routing strategies or simple point-to-point communication, lacking a systematic design for multi-machine collaborative formation. In situations of drastic changes in network topology or partial node failure, existing protocols struggle to guarantee effective information transmission and distributed task collaboration, especially in denied environments, where the system's robustness faces severe challenges.

[0008] Therefore, it is necessary to propose a solution to improve one or more problems existing in the above-mentioned related technical solutions.

[0009] It should be noted that the information disclosed in the background section above is only used to enhance the understanding of the background of this application, and therefore may include information that does not constitute prior art known to those skilled in the art. Summary of the Invention

[0010] This application provides a multi-aircraft cooperative ad hoc network communication method for aviation search and rescue missions, the method comprising the following steps:

[0011] The ad hoc network communication system is configured using the Time Division Multiple Access (TDMA) protocol to obtain a configured ad hoc network communication system; the configuration process is as follows:

[0012] The communication time of the ad hoc network communication system is divided into multiple time elements using the time division multiple access networking protocol. Each time element is further divided into multiple time frames, and each time frame is further divided into multiple time slots.

[0013] Based on the communication mission requirements in aviation search and rescue scenarios, multiple functional groups are defined in the ad hoc network communication system.

[0014] Based on the type of functional group, all time slots in each time frame within each time element are arranged in a cyclical alternation according to time order to obtain the cyclical allocation sequence corresponding to each time frame within each time element;

[0015] Based on all cyclic allocation sequences, predefined time slot blocks corresponding to each functional group in each time frame within each time cell are constructed. The constraints of each predefined time slot block include the type of functional group, the starting time slot index, and the fixed step size parameter.

[0016] Based on all predefined time slot blocks, determine the time slot index span and time slot time span corresponding to each functional group in each time frame within each time element;

[0017] Within the same time cell, every two consecutive time frames constitute a time slot allocation period. Each time slot allocation period starts from the first time slot of the current time frame and ends at the last time slot of the next adjacent time frame.

[0018] All cyclic allocation sequences within each time cell are combined into a corresponding full time slot set. From each full time slot set, all time slots that meet the constraints of each predefined time slot block within the corresponding time cell are selected, resulting in a time slot subset corresponding to each predefined time slot block within each time cell. All time slot subsets form the legal time slot set of the corresponding time cell, and all legal time slot sets form the total legal time slot set.

[0019] The configured self-organizing network communication system is used to schedule and allocate resources for various air search and rescue missions.

[0020] Furthermore, the functional groups include control synchronization functional groups, exploration and positioning functional groups, and dynamic search functional groups. The control synchronization functional group uses... It indicates that the location function group uses This indicates that the dynamic search function group uses... express;

[0021] The expression for a cyclically assigned sequence is:

[0022] (1)

[0023] in, Indicates the first Within the first time element The first one arranged in the control synchronization function group in the first time frame Each time slot Indicates the first Within the first time element The first time frame arranged in the search and positioning function group Each time slot Indicates the first Within the first time element The first one in the dynamic search function group in the first time frame Each time slot.

[0024] Furthermore, the expression for the predefined time slot block is:

[0025] (2)

[0026] in, Indicates the first Within the first time element In the 1st time frame Predefined time slot blocks corresponding to each functional group Indicates the first Within the first time element In the 1st time frame Types of functional groups Indicates the first Within the first time element In the 1st time frame The first functional group corresponding to the Each time slot Indicates the first Within the first time element In the 1st time frame The fixed step size parameters corresponding to each functional group , Indicates the first Within the first time element In the 1st time frame The basic index step size corresponding to each time slot in the functional group. Indicates the first Within the first time element The number of all function groups in each time frame Indicates the first Within the first time element In the 1st time frame Interval factor for functional groups;

[0027] Index span refers to the difference between the index of the first slot and the index of the last slot in each functional group within the index sequence of the cyclic allocation sequence.

[0028] The time span refers to the length of time from the beginning of the first time slot to the end of the last time slot in each functional group within a cyclic allocation sequence.

[0029] Furthermore, the first The full time-slot set corresponding to each time element is used express;

[0030] The expression for the set of valid time slots is:

[0031] (3)

[0032] in, Indicates the first The set of legal time slots corresponding to each time element Indicates the first Within the first time element The first time frame A subset of time slots corresponding to a predefined time slot block This indicates the number of all predefined time slot blocks. .

[0033] Furthermore, the steps for resource scheduling and allocation for various aerial search and rescue missions using a configured ad hoc network communication system include:

[0034] All collected aerial search and rescue missions are compiled into an aerial search and rescue mission set, and the aerial search and rescue mission set is input into the configured self-organizing network communication system;

[0035] The configured self-organizing network communication system is divided into multiple different configuration phases according to the communication requirements of all air search and rescue missions, and each air search and rescue mission is assigned to the corresponding configuration phase.

[0036] The configuration phase includes the setup phase, the operation phase, and the continuous phase. The setup phase corresponds to the control and synchronization function group, the operation phase corresponds to the exploration and positioning function group, and the continuous phase corresponds to the dynamic search function group.

[0037] The number of all legal time slots allocated to each air search and rescue mission in each configuration phase is determined using the configured ad hoc network communication system.

[0038] The configured self-organizing network communication system is used to allocate all available and valid time slots during the operational phase to the corresponding air search and rescue missions during the continuous phase.

[0039] Furthermore, the tasks performed during the establishment phase include: network access task, coarse synchronization task, fine synchronization task, and basic search task;

[0040] The expression for the subset of legal time slots obtained during the setup phase of the air search and rescue mission is:

[0041] (4)

[0042] in, Indicates the first The first time dimension The first phase of the establishment within the time slot allocation cycle A subset of legal time slots obtained from an aviation search and rescue mission. Indicates the first The first time dimension The set of legal time slots obtained during the setup phase within each time slot allocation cycle. , , Indicates the first The minimum number of legal time slots obtained for an air search and rescue mission Indicates the first The length of data that needs to be transmitted in an aerial search and rescue mission Indicates the first The effective payload length of each time slot Indicates rounding up;

[0043] The tasks performed during the operation phase include: single exploration tasks, continuous exploration tasks, and location exploration tasks;

[0044] The expression for the subset of legal time slots obtained during the operational phase of an air search and rescue mission is:

[0045] (5)

[0046] in, Indicates the first The first time dimension The first phase of operation within the time slot allocation cycle A subset of legal time slots obtained from an aviation search and rescue mission. Indicates the first The first time dimension A subset of occupied legal time slots during the operation phase within a time slot allocation cycle. , Indicates the first The first time dimension The set of legal time slots obtained during the operation phase within each time slot allocation cycle. Indicates the first The first time dimension A subset of idle legal time slots during the operation phase within a time slot allocation cycle. ;

[0047] The tasks performed during the continuous phase include: voice tasks and status broadcast tasks;

[0048] The expression for the subset of legal time slots obtained during the sustained phase of an air search and rescue mission is:

[0049] (6)

[0050] in, Indicates the first The first time dimension The first phase of the continuous phase within the time slot allocation cycle A subset of legal time slots obtained from an aviation search and rescue mission. Indicates the first The first time dimension The set of legal time slots obtained during the continuous phase within a time slot allocation cycle. , Indicates the first The first time dimension The basic legal time slot subset for the continuous phase within a time slot allocation period ;

[0051] The total set of legal time slots includes the set of legal time slots during the establishment phase, the set of legal time slots during the operation phase, and the set of legal time slots during the continuous phase.

[0052] Furthermore, the first The first time dimension The time slot interval between any two adjacent legal time slots in the continuous phase within a time slot allocation period is represented as follows: , Indicates the first One legal time slot, Indicates the relationship with the first The next legal time slot adjacent to a legal time slot, , will the The first time dimension The time slot interval threshold between any two adjacent legal time slots in the continuous phase within a time slot allocation period is expressed as follows: , , Indicates the first The first time dimension The maximum continuous waiting time allowed for a task during the continuous phase within a time slot allocation period. Indicates the first The first time dimension The duration of each legal time slot in the continuous phase within a time slot allocation cycle;

[0053] when At that time, the task continuity requirements of the continuous phase are met;

[0054] when At that time, the continuous task carrying requirements of the sustained phase are not met.

[0055] Furthermore, during the operational phase, the configured ad hoc network communication system allocates all legal time slots using a uniform allocation strategy;

[0056] The expression for allocating all legal time slots using a uniform allocation strategy is as follows:

[0057] (7)

[0058] in, Indicates the first The first time dimension The first phase of operation within the time slot allocation cycle One legal time slot, Indicates the first The first time dimension The first phase of operation within the time slot allocation cycle An index of the legal time slots required for an aviation search and rescue mission. This indicates rounding down. Represents absolute value. Let represent the set of all left-hand elements that satisfy the condition on the right. It represents the set of natural numbers.

[0059] Furthermore, during the operation phase, the configured self-organizing network communication system sets up multiple task instruction detection windows based on the allocation cycle of all time slots, the location of all legal time slots, and the instruction issuance time of all air search and rescue missions. Each task instruction detection window corresponds to a legal time slot.

[0060] A time slot status decision function is introduced in each task instruction detection window to detect the handover status of the current legal time slot;

[0061] The expression for the slot state decision function is:

[0062] (8)

[0063] in, Indicates the first The time slot status judgment function corresponding to the task instruction detection window;

[0064] when When, it indicates the first If the task instruction detection window determines that the current valid time slot is an occupied valid time slot, the configured ad hoc network communication system will continue to execute the corresponding single exploration task, continuous exploration task, or location exploration task.

[0065] when When, it indicates the first When a task instruction detection window determines that the current valid time slot is an idle valid time slot, the configured ad hoc network communication system will transfer the idle valid time slot to the continuous phase for executing the corresponding voice task or status broadcast task.

[0066] This application provides a multi-aircraft cooperative ad hoc network communication method for aerial search and rescue missions, which has at least the following beneficial effects:

[0067] (1) According to the type of functional group, this application arranges all time slots in each time frame in each time element in a cyclical alternation according to time order to obtain the cyclical allocation sequence corresponding to each time frame in each time element, thereby ensuring the uniform distribution of all time slots. The multiple time slots contained in each functional group are arranged in a periodic structure, which can provide stable and efficient time slot resource scheduling.

[0068] (2) This application uses a configured self-organizing network communication system to determine the number of all legal time slots allocated to each aviation search and rescue mission in each configuration phase, and allocates all the idle legal time slots in the operation phase to the aviation search and rescue missions corresponding to the continuous phase. This improves the time slot utilization rate and enables multiple aviation search and rescue missions to be executed in parallel, thereby ensuring the normal execution of the search mission while enabling the continuous carrying of voice missions and status broadcast missions.

[0069] (3) This application introduces the concept of task scheduling into the time slot allocation process of multi-aircraft collaborative ad hoc network communication for air search and rescue. Combined with the dynamic reallocation mechanism within the total set of legal time slots, it realizes the differentiation of legal time slot resources occupied by different air search and rescue tasks in the establishment, operation and continuous phases. Thus, without changing the macro time structure of the multi-aircraft collaborative ad hoc network communication system, it can significantly improve the time slot utilization and multi-task parallel execution capability in the multi-aircraft collaborative communication process. Attached Figure Description

[0070] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application. It is obvious that the drawings described below are merely some embodiments of this application, and those skilled in the art can obtain other drawings based on these drawings without any inventive effort.

[0071] Figure 1 This illustration shows a flowchart of a multi-aircraft cooperative ad hoc network communication method for aviation search and rescue missions, as shown in an exemplary embodiment of this application.

[0072] Figure 2 The exemplary embodiments of this application show the first The first time dimension A schematic diagram showing the cyclical alternation of all time slots in a time frame;

[0073] Figure 3 This application illustrates an exemplary embodiment of a self-organizing network communication system used to respectively connect the first... The first time dimension A diagram illustrating the allocation of all time slots within a time frame in each configuration phase;

[0074] Figure 4 The diagram shows a comparison of the transmission workload when using the static time division multiple access (TDMI) time slot allocation strategy and the dynamic time division multiple access (TDMI) time slot allocation strategy proposed in this application, respectively, in the simulation experiment of this application.

[0075] Figure 5 The diagram shows a comparison of time slot utilization rates in simulation experiments using the static time division multiple access (TDMI) time slot allocation strategy and the dynamic time division multiple access (TDMI) time slot allocation strategy proposed in this application. Detailed Implementation

[0076] Exemplary embodiments will now be described more fully with reference to the accompanying drawings. However, these exemplary embodiments can be implemented in many forms and should not be construed as limited to the examples set forth herein; rather, they are provided to make this application more comprehensive and complete, and to fully convey the concept of the exemplary embodiments to those skilled in the art. The described features, structures, or characteristics may be combined in any suitable manner in one or more embodiments.

[0077] Furthermore, the accompanying drawings are merely illustrative of this application and are not necessarily drawn to scale. The same reference numerals in the drawings denote the same or similar parts, and therefore repeated descriptions of them will be omitted. Some block diagrams shown in the drawings are functional entities and do not necessarily correspond to physically or logically independent entities. These functional entities can be implemented in software, in one or more hardware modules or integrated circuits, or in different network and / or processor devices and / or microcontroller devices.

[0078] To address the problem that most current networking protocols in the field of aviation search and rescue communication technology only support interaction among a small number of nodes, such as in polling protocols where each node takes turns sending information, this means that after a node finishes sending information in one round, it must wait for the polling cycle to end before it can send the next message. This effectively occupies all of the network resources of that node, preventing other nodes from sending messages while the current node is sending. Furthermore, the more nodes there are, the longer the polling cycle becomes, resulting in very low time slot utilization and an inability to accommodate multiple devices communicating simultaneously within the network. Therefore, this application proposes a multi-machine cooperative ad hoc network communication method for aviation search and rescue missions. This method utilizes a time-division multiple access (TDMA) networking protocol to divide the ad hoc network communication system into time structures, controlling the sending and receiving of each node through a time scale. This enables multiple functions to operate simultaneously among multiple nodes, allowing multiple aviation search and rescue missions to be completed in a shorter time and improving time slot utilization.

[0079] The following will provide a more detailed description of a multi-aircraft cooperative ad hoc network communication method for air search and rescue missions proposed in the embodiments of this application.

[0080] The application embodiments propose a multi-aircraft cooperative ad hoc network communication method for aerial search and rescue missions, such as... Figure 1 As shown, the following steps may be included:

[0081] Step S101 of this embodiment: Configure the ad hoc network communication system using the Time Division Multiple Access (TDMA) networking protocol to obtain the configured ad hoc network communication system. The configuration process of step S101 of this embodiment is as follows:

[0082] The first step is to use the time division multiple access (TDMA) networking protocol to divide the communication time of the ad hoc network communication system into multiple time elements, then divide each time element into multiple time frames, and finally divide each time frame into multiple time slots.

[0083] The second step is to define multiple functional groups in the ad hoc network communication system based on the communication mission requirements in the aviation search and rescue scenario.

[0084] Furthermore, in this embodiment, the functional groups include a control synchronization functional group, a search and positioning functional group, and a dynamic search functional group. The control synchronization functional group uses... It indicates that the location function group uses This indicates that the dynamic search function group uses... express.

[0085] The third step, as Figure 2 As shown, according to the type of functional group, all time slots in each time frame within each time element are arranged in a cyclical alternation according to time order to obtain the cyclical allocation sequence corresponding to each time frame within each time element.

[0086] In this embodiment, the expression for the cyclic allocation sequence is:

[0087] (1)

[0088] in, Indicates the first Within the first time element The first one arranged in the control synchronization function group in the first time frame Each time slot Indicates the first Within the first time element The first time frame arranged in the search and positioning function group Each time slot Indicates the first Within the first time element The first one in the dynamic search function group in the first time frame Each time slot.

[0089] The fourth step is to construct predefined time slot blocks corresponding to each functional group in each time frame within each time cell, based on all cyclic allocation sequences. The constraints of each predefined time slot block include the type of functional group, the starting time slot index, and the fixed step size parameter.

[0090] Furthermore, the expression for the predefined time slot block is:

[0091] (2)

[0092] in, Indicates the first Within the first time element In the 1st time frame Predefined time slot blocks corresponding to each functional group Indicates the first Within the first time element In the 1st time frame Types of functional groups Indicates the first Within the first time element In the 1st time frame The first functional group corresponding to the Each time slot Indicates the first Within the first time element In the 1st time frame The fixed step size parameters corresponding to each functional group , Indicates the first Within the first time element In the 1st time frame The basic index step size corresponding to each time slot in the functional group. Indicates the first Within the first time element The number of all function groups in each time frame Indicates the first Within the first time element In the 1st time frame Interval factors for functional groups.

[0093] The fifth step is to determine the slot index span and slot time span for each functional group in each time frame within each time element, based on all predefined slot blocks.

[0094] In this embodiment, the index span refers to the difference between the index of the first time slot and the index of the last time slot in each functional group within the index sequence of the cyclic allocation sequence.

[0095] In this embodiment, the time span refers to the length of time from the beginning of the first time slot to the end of the last time slot in each functional group in the cyclic allocation sequence.

[0096] The sixth step is to form a time slot allocation cycle for every two consecutive time frames within the same time cell. Each time slot allocation cycle starts from the first time slot of the current time frame and ends at the last time slot of the next adjacent time frame.

[0097] Step 7: All cyclic allocation sequences within each time cell are combined into a corresponding full time slot set. From each full time slot set, all time slots that meet the constraints of each predefined time slot block within the corresponding time cell are selected to obtain a time slot subset corresponding to each predefined time slot block within each time cell. All time slot subsets form the legal time slot set of the corresponding time cell, and all legal time slot sets form the total legal time slot set.

[0098] Furthermore, in this embodiment, the first The full time-slot set corresponding to each time element is used express.

[0099] Furthermore, the expression for the set of legal time slots is:

[0100] (3)

[0101] in, Indicates the first The set of legal time slots corresponding to each time element Indicates the first Within the first time element The first time frame A subset of time slots corresponding to a predefined time slot block This indicates the number of all predefined time slot blocks. .

[0102] At this point, a configured self-organizing network communication system is obtained.

[0103] Step S102 of this embodiment: as follows Figure 3 As shown, a configured ad hoc network communication system is used to schedule and allocate resources for various air search and rescue missions. Step S102 in this embodiment may include the following sub-steps:

[0104] Sub-step S1021: Combine all collected aerial search and rescue missions into an aerial search and rescue mission set, and input the aerial search and rescue mission set into the configured self-organizing network communication system.

[0105] Furthermore, to effectively distinguish and schedule the time slot allocation period, the parity of the time frame number is used to determine the allocation stage of the current time frame. This allows for periodic multiplexing and dynamic switching between time synchronization and task communication without introducing additional time slots.

[0106] If the time frame number is odd, the first valid time slot belonging to the control synchronization function group within that time frame is fixedly configured as a dedicated time slot for the network time reference, used to broadcast time synchronization information across the entire network.

[0107] If the time frame number is even, the first valid time slot belonging to the control synchronization function group within that time frame is released and no longer used for time synchronization, but instead used for functions such as exploration tasks.

[0108] Sub-step S1022: The configured self-organizing network communication system divides the communication mission requirements of all air search and rescue missions into multiple different configuration stages, and assigns each air search and rescue mission to the corresponding configuration stage.

[0109] Sub-step S1023: The configuration phase includes a setup phase, an operation phase, and a continuous phase. The setup phase corresponds to the control synchronization function group, the operation phase corresponds to the exploration and positioning function group, and the continuous phase corresponds to the dynamic search function group.

[0110] The control and synchronization function group is used to carry out control and synchronization tasks such as broadcast network reference time, node access control, coarse synchronization and fine synchronization.

[0111] The exploration and positioning function group is used to carry out exploration and positioning tasks such as single exploration, continuous exploration, location exploration, and search response.

[0112] The dynamic search function group is used to handle dynamic search tasks such as search initiation, dynamic search scheduling, and task triggering during the runtime phase.

[0113] Furthermore, the tasks executed during the establishment phase include: network access, coarse synchronization, fine synchronization, and basic search. The network access task enables the node to complete network registration and obtain initial communication eligibility. The coarse synchronization task establishes a preliminary alignment between the node and the network time base. The fine synchronization task further refines the local time boundary based on the coarse synchronization task to meet the timing requirements for subsequent tasks accessing legitimate time slots. The basic search task quickly establishes a basic search relationship after the node completes the coarse synchronization task, confirming the initial reachability of the target node or collaborating nodes. The tasks in the establishment phase have clear execution order constraints; the node must complete the network access, coarse synchronization, fine synchronization, and basic search tasks sequentially. The node cannot effectively execute the next task if the previous task is not completed. Simultaneously, the establishment phase has a low tolerance for task waiting latency; if critical tasks are unable to obtain legitimate time slot support for an extended period, it will directly affect the access efficiency of the node and the startup speed of subsequent collaborative communication.

[0114] When an airborne search mission is in the establishment phase, network access, coarse synchronization, fine synchronization, and basic search tasks are mapped to their respective legal time slots within the establishment phase. The set of legal time slots for the establishment phase consists of all legal time slots reserved for control synchronization and access within a complete time slot allocation cycle. These legal time slots have temporal priority over those in the operation and continuous phases. In specific allocation, tasks in the establishment phase are preferentially mapped to legal time slots with earlier timestamps and shorter intervals to ensure the continuous completion of node access, time alignment, and basic search tasks.

[0115] The expression for the subset of legal time slots obtained during the setup phase of the air search and rescue mission is:

[0116] (4)

[0117] in, Indicates the first The first time dimension The first phase of the establishment within the time slot allocation cycle A subset of legal time slots obtained from an aviation search and rescue mission. Indicates the first The first time dimension The set of legal time slots obtained during the setup phase within each time slot allocation cycle. , , Indicates the first The minimum number of legal time slots obtained for an air search and rescue mission Indicates the first The length of data that needs to be transmitted in an aerial search and rescue mission Indicates the first The effective payload length of each time slot This indicates rounding up to the nearest integer.

[0118] Furthermore, the tasks executed during the operation phase include: single-time exploration tasks, continuous exploration tasks, and location exploration tasks. A single-time exploration task initiates a single exploration request to the target node within the current time slot allocation period and receives the corresponding response, thus completing target confirmation or status acquisition in one go. Continuous exploration tasks repeatedly initiate exploration requests and continuously receive corresponding responses within multiple consecutive time slot allocation periods to achieve continuous tracking of the target node's status. Location exploration tasks acquire location-related information of the target node and complete the corresponding location status updates.

[0119] Tasks in the runtime phase no longer have the strict execution order constraints of the setup phase. Its main characteristic is that various tasks can be evenly distributed while satisfying functional correspondence and time slot allocation period constraints. Specifically, single-search tasks, continuous-search tasks, and location-search tasks are mapped to the corresponding legal time slots in the runtime phase. The time intervals between each search task are kept as even as possible to avoid time slot conflicts during task allocation and to ensure the periodic execution of each search task.

[0120] When an air search and rescue mission is in the operational phase, single search missions, continuous search missions, and location search missions are mapped to the corresponding legal time slots of the operational phase. Based on the legal time slot set of the operational phase, the missions are uniformly allocated according to the distribution pattern within the complete time slot allocation cycle. This allows each search mission to complete periodic scheduling without time slot conflicts.

[0121] The expression for the subset of legal time slots obtained during the operational phase of an air search and rescue mission is:

[0122] (5)

[0123] in, Indicates the first The first time dimension The first phase of operation within the time slot allocation cycle A subset of legal time slots obtained from an aviation search and rescue mission. Indicates the first The first time dimension A subset of occupied legal time slots during the operation phase within a time slot allocation cycle. , Indicates the first The first time dimension The set of legal time slots obtained during the operation phase within each time slot allocation cycle. Indicates the first The first time dimension A subset of idle legal time slots during the operation phase within a time slot allocation cycle. .

[0124] Furthermore, the tasks executed during the continuous phase include voice tasks and status broadcasting tasks. Voice tasks are used to carry out voice broadcasting, voice interaction, and continuous voice communication between nodes. Status broadcasting tasks are used to periodically send information such as node status, task status, or collaborative work status to maintain continuous awareness of the operational status of each node within the network.

[0125] The persistent phase does not undertake the access and synchronization functions of the establishment phase, nor the active search functions of the operation phase. The main characteristic of the persistent phase is that, after network access, synchronization, and basic search are completed, it continuously occupies the remaining available legal time slots as a long-term background task. Background occupancy refers to the fact that voice tasks and status broadcast tasks, without changing the unified time structure, use the dynamic transfer results of the basic legal time slot subset and the idle legal time slot subset of the operation phase as carrying resources to transmit data while meeting continuity requirements.

[0126] After the establishment and operation phases are completed, the network has accomplished key functions such as network access, synchronization, and basic exploration, and all nodes are in a stable collaborative working state. In the continuous phase, the main communication requirements are voice tasks and status broadcasts. The communication process in the continuous phase is characterized by uncertain duration and dynamically changing task data volume over time. Based on this, tasks in the continuous phase are mapped to the set of legal time slots for the continuous phase, as well as the expanded set of available legal time slots for the continuous phase, to ensure stable operation of continuous tasks while exploration tasks run normally.

[0127] Therefore, during the continuous phase, instead of reserving continuous and exclusive legal time slots for a single voice call, the continuous voice data is split into several data units and distributed and mapped to legal time slots that have not yet been allocated for transmission and reception, thereby avoiding the voice task's long-term exclusive use of legal time slot resources.

[0128] The expression for the subset of legal time slots obtained during the sustained phase of an air search and rescue mission is:

[0129] (6)

[0130] in, Indicates the first The first time dimension The first phase of the continuous phase within the time slot allocation cycle A subset of legal time slots obtained from an aviation search and rescue mission. Indicates the first The first time dimension The set of legal time slots obtained during the continuous phase within a time slot allocation cycle. , Indicates the first The first time dimension The basic legal time slot subset for the continuous phase within a time slot allocation period .

[0131] Furthermore, to ensure the continuity of tasks during the continuous phase under fragmented legal time slot conditions, it is necessary to constrain the maximum permissible interval between each legal time slot in the continuous phase. Therefore, the first... The first time dimension The time slot interval between any two adjacent legal time slots in the continuous phase within a time slot allocation period is represented as follows: , Indicates the first One legal time slot, Indicates the relationship with the first The next legal time slot adjacent to a legal time slot, , will the The first time dimension The time slot interval threshold between any two adjacent legal time slots in the continuous phase within a time slot allocation period is expressed as follows: , , Indicates the first The first time dimension The maximum continuous waiting time allowed for a task during the continuous phase within a time slot allocation period. Indicates the first The first time dimension The duration of each legal time slot in the continuous phase within a time slot allocation cycle;

[0132] when At that time, the task continuity requirements of the continuous phase are met;

[0133] when At that time, the continuous task carrying requirements of the sustained phase are not met.

[0134] Furthermore, during the operational phase, the configured ad hoc network communication system allocates all legal time slots using a uniform allocation strategy.

[0135] The expression for allocating all legal time slots using a uniform allocation strategy is as follows:

[0136] (7)

[0137] in, Indicates the first The first time dimension The first phase of operation within the time slot allocation cycle One legal time slot, Indicates the first The first time dimension The first phase of operation within the time slot allocation cycle An index of the legal time slots required for an aviation search and rescue mission. This indicates rounding down. Represents absolute value. Let represent the set of all left-hand elements that satisfy the condition on the right. It represents the set of natural numbers.

[0138] here, This represents the floor function of the ratio of the number of available valid time slots during the runtime phase to the minimum number of valid time slots required by the task, used to determine the base interval between two adjacent valid time slots. Cannot be If the result is divisible, all remaining valid time slots are retained for subsequent dynamic transfer or supplementary allocation.

[0139] Sub-step S1024: Use the configured ad hoc network communication system to determine the number of all legal time slots allocated to each aviation search and rescue mission in each configuration phase.

[0140] Sub-step S1025: Using the configured self-organizing network communication system, all available and valid time slots in the operation phase are allocated to the corresponding air search and rescue missions in the continuous phase.

[0141] Furthermore, through the aforementioned time slot allocation method, voice tasks can be transmitted in a fragmented and dynamically scheduled manner within the legal time slots of the continuous phase. This allows some nodes to perform voice tasks while other nodes can still use the allocated legal time slots for performing search, exploration, and other functions to execute tasks in parallel without waiting for the voice task to finish before starting the relevant tasks.

[0142] During the continuous phase, to further improve the utilization efficiency of legal time slot resources throughout the entire time slot allocation cycle, a dynamic transfer mechanism is introduced for all idle legal time slots during the operational phase. During the operational phase, the configured ad hoc network communication system sets up multiple task instruction detection windows based on all time slot allocation cycles, the location of all legal time slots, and the instruction issuance time of all air search and rescue missions. Each task instruction detection window corresponds to one legal time slot.

[0143] A time slot status decision function is introduced in each task instruction detection window to detect the handover status of the current legal time slot;

[0144] The expression for the slot state decision function is:

[0145] (8)

[0146] in, Indicates the first The time slot status judgment function corresponding to the task instruction detection window;

[0147] when When, it indicates the first If the task instruction detection window determines that the current valid time slot is an occupied valid time slot, the configured ad hoc network communication system will continue to execute the corresponding single exploration task, continuous exploration task, or location exploration task.

[0148] when When, it indicates the first When a task instruction detection window determines that the current valid time slot is an idle valid time slot, the configured ad hoc network communication system will transfer the idle valid time slot to the continuous phase for executing the corresponding voice task or status broadcast task.

[0149] It should be noted that, by Figure 1 As can be seen, in step S101 of this application, a hierarchical division structure of time elements, time frames, and time slots is constructed, all time slots are configured in three different cyclically alternating functional groups, and a complete definition of the time slot allocation cycle is given, establishing a set of legal time slots. In step S102 of this application, the configured ad hoc network communication system is divided into a setup phase, an operation phase, and a continuous phase. In the setup phase, legal time slots are preferentially allocated to critical tasks, and validity guarantees are initiated. In the operation phase, if the ad hoc network communication system detects an operation phase instruction, it follows the original allocation and performs periodic allocations related to basic search tasks and exploration tasks. If no relevant instruction is detected, the current legal time slot is transferred to the relevant tasks in the continuous phase. In the continuous phase, voice tasks utilize a large amount of remaining legal time slot resources for transmission, thereby improving time slot utilization and ensuring the parallel execution of multiple air search and rescue tasks. Here, the decision result of the time slot state decision function is obtained through relevant instructions. If a relevant instruction is detected, the decision result of the time slot state decision function is 1; if no relevant instruction is detected, the decision result of the time slot state decision function is 0. In this case, the transfer can be carried out using formula (8).

[0150] It should be noted that, by Figure 2 As can be seen, depending on the type of functional group, all time slots in each time frame within each time element are arranged in a cyclical alternation according to time order, ensuring the uniform distribution of time slots and arranging them according to a periodic structure, thereby providing stable and efficient time slot resource scheduling.

[0151] It should be noted that, by Figure 3As can be seen, during the setup phase, the ad hoc network communication system reserves several pre-defined legal time slots. The network time reference device broadcasts the system time reference through these pre-defined legal time slots. Nodes awaiting network access complete the node access and fine synchronization tasks based on the system time reference. Subsequently, during the operation phase, exploratory tasks are mapped to designated time slots according to their functional type, and the corresponding legal time slots appear periodically in a predetermined order within the time slot allocation period. For tasks related to the continuous phase, voice tasks are allocated to a larger number of relatively continuous remaining legal time slots, thereby ensuring the continuous carrying of voice tasks while guaranteeing the normal execution of search and exploration functions.

[0152] This application proposes a multi-aircraft cooperative ad hoc network communication method for air search and rescue missions. It comprehensively utilizes the temporal stability and predictability inherent in time slot structures, as well as the advantages of dynamic scheduling mechanisms in improving time slot utilization and multi-task parallel execution capabilities. While maintaining the existing time cell structure and the total set of legal time slots, a task-stage-aware time slot reallocation mode is constructed. By differentially scheduling tasks with different temporal dependencies, collaborative operation of multiple communication tasks within the same network is achieved. This effectively overcomes the problems of large response latency and low resource utilization in traditional fixed time slot allocation methods in multi-aircraft cooperative scenarios, thereby significantly improving the overall efficiency and mission continuity of the air search and rescue ad hoc network communication system.

[0153] To verify the superiority of the multi-aircraft cooperative ad hoc network communication method for aviation search and rescue missions proposed in this application, the following simulation experiments were conducted.

[0154] Simulation experiment parameter settings:

[0155] Each time unit lasts for 327.68 minutes, and each time unit is divided into 64 time frames, each with a duration of 307.2 seconds. Each time frame is further divided into 1536 time slots, each with a duration of 200 milliseconds. In this simulation experiment, a unified time slot structure is used as the basis for comparison. The unified time slot structure is consistent with both the static time division multiple access (TDMA) time slot allocation strategy and the dynamic TDMA time slot allocation strategy proposed in this application.

[0156] Each time unit includes a set of 38,912 valid time slots, which are selected from predefined time slot blocks; other time slots do not participate in time slot allocation. In the task load simulation, a dynamic task input scenario is used to simulate the fluctuation of task requirements over time in air search and rescue missions. The dynamic task input consists of basic task load, random fluctuations, and sudden task injections. The simulation duration for the task volume comparison experiment is set to 1000 seconds, the base value of the average task volume is set to 1000, random jitter is generated using Gaussian perturbations with a standard deviation of 40, and 15 sudden tasks are randomly injected, each lasting 11 seconds, with a single burst amplitude not exceeding 150.

[0157] The simulation duration for the time slot utilization comparison experiment was set to 1000 seconds, and the average task load baseline was also set to 1100. Random jitter was generated using a Gaussian perturbation with a standard deviation of 50, and 12 burst tasks were randomly injected, each burst lasting 16 seconds, with a single burst increment not exceeding 120. Thus, while maintaining the original time-division multiple access (TDMA) structure, time slot grouping method, and timing organization rules, the set of legal time slots is treated as a unified schedulable resource pool. Under the same task input conditions, the performance differences between the static TDMA time slot allocation strategy and the dynamic TDMA time slot allocation strategy proposed in this application are compared.

[0158] The above simulation experiments are applicable to aviation search and rescue communication scenarios with a unified time slot structure, a legal time slot set, and a phase-aware scheduling mechanism. They are especially suitable for application scenarios where the task load changes over time, there is sudden task injection, and it is necessary to take into account both search and exploration tasks and continuous communication tasks.

[0159] This simulation experiment consists of two parts. The first part compares the transmission workload when using a static time division multiple access (TDMI) time slot allocation strategy and the dynamic time division multiple access (TDMI) time slot allocation strategy proposed in this application, such as... Figure 4 As shown, in a dynamic network environment, the number of transmission tasks is relatively low when using a static time division multiple access (TDMA) time slot allocation strategy. However, when using the dynamic time division multiple access (TDMA) time slot allocation strategy proposed in this application, the response time of the ad hoc network communication system is significantly shortened and the number of transmission tasks is significantly increased through phase-aware dynamic time slot allocation.

[0160] The second part compares the time slot utilization rates when using a static time division multiple access (TDMA) time slot allocation strategy and the dynamic TDMA time slot allocation strategy proposed in this application. For example... Figure 5As shown, when using a static time-division multiple access (TDMA) time slot allocation strategy, the time slot utilization rate of the ad hoc network communication system remains at a low level overall, and it drops significantly when task demand fluctuates. This reflects the limited adaptability of the ad hoc network communication system to dynamic tasks. In contrast, when using the dynamic TMA time slot allocation strategy proposed in this application, the overall fluctuation range of the ad hoc network communication system is smaller, indicating that it can fully utilize idle or unoccupied legal time slot resources when task load changes.

[0161] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of the embodiments of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0162] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. In addition, those skilled in the art can combine and integrate the different embodiments or examples described in this specification.

[0163] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the scope of the technology disclosed in this application, and these modifications or substitutions should all be covered within the scope of protection of this application.

[0164] Other embodiments of this application will readily occur to those skilled in the art upon consideration of the specification and practice of the invention disclosed herein. This application is intended to cover any variations, uses, or adaptations of this application that follow the general principles of this application and include common knowledge or customary techniques in the art not disclosed herein.

Claims

1. A multi-aircraft cooperative ad hoc network communication method for aerial search and rescue missions, characterized in that, The method includes the following steps: The ad hoc network communication system is configured using the Time Division Multiple Access (TDMA) protocol to obtain a configured ad hoc network communication system; the configuration process is as follows: The communication time of the ad hoc network communication system is divided into multiple time elements using the time division multiple access networking protocol, each time element is divided into multiple time frames, and each time frame is divided into multiple time slots. Based on the communication mission requirements in the aviation search and rescue scenario, multiple functional groups are defined in the self-organizing network communication system. According to the type of the functional group, all time slots in each time frame within each time element are arranged in a cyclical alternation according to time order to obtain a cyclical allocation sequence corresponding to each time frame within each time element; Based on all the cyclic allocation sequences, predefined time slot blocks corresponding to each of the functional groups in each time frame within each time cell are constructed respectively. The constraints of each predefined time slot block include the type of the functional group, the starting time slot index, and the fixed step size parameter. Based on all the predefined time slot blocks, determine the time slot index span and time slot time span corresponding to each functional group in each time frame within each time element; Within the same time cell, every two consecutive time frames constitute a time slot allocation period. Each time slot allocation period starts from the first time slot of the current time frame and ends at the last time slot of the next adjacent time frame. Each time slot set is formed by combining all the cyclic allocation sequences within each time cell into a corresponding full time slot set. Then, all time slots that meet the constraint conditions of each predefined time slot block within the corresponding time cell are selected from each full time slot set to obtain a time slot subset corresponding to each predefined time slot block within each time cell. All time slot subsets form a legal time slot set for the corresponding time cell, and all legal time slot sets form a total legal time slot set. The configured self-organizing network communication system is used to schedule and allocate resources for various aviation search and rescue missions.

2. The multi-aircraft cooperative ad hoc network communication method for air search and rescue missions according to claim 1, characterized in that, The functional groups include control synchronization functional groups, exploration and positioning functional groups, and dynamic search functional groups. The control synchronization functional groups are used for… This indicates that the exploration and positioning function group uses This indicates that the dynamic search function group uses... express; The expression for the cyclic allocation sequence is: (1) in, Indicates the first Within the first time element The first one arranged in the control synchronization function group in the first time frame Each time slot Indicates the first Within the first time element The first time frame arranged in the search and positioning function group Each time slot Indicates the first Within the first time element The first one in the dynamic search function group in the first time frame Each time slot.

3. The multi-aircraft cooperative ad hoc network communication method for air search and rescue missions according to claim 1, characterized in that, The expression for the predefined time slot block is: (2) in, Indicates the first Within the first time element In the 1st time frame Predefined time slot blocks corresponding to each functional group Indicates the first Within the first time element In the 1st time frame Types of functional groups Indicates the first Within the first time element In the 1st time frame The first functional group corresponding to the Each time slot Indicates the first Within the first time element In the 1st time frame The fixed step size parameters corresponding to each functional group , Indicates the first Within the first time element In the 1st time frame The basic index step size corresponding to each time slot in the functional group. Indicates the first Within the first time element The number of all function groups in each time frame Indicates the first Within the first time element In the 1st time frame Interval factor for functional groups; The index span refers to the difference between the index of the first time slot and the index of the last time slot in each of the functional groups in the index sequence of the cyclic allocation sequence. The time span refers to the length of time from the beginning of the first time slot to the end of the last time slot in each of the functional groups in the cyclic allocation sequence.

4. The multi-aircraft cooperative ad hoc network communication method for air search and rescue missions according to claim 1, characterized in that, No. The full time slot set corresponding to each time element is used express; The expression for the set of legal time slots is: (3) in, Indicates the first The set of legal time slots corresponding to each time element Indicates the first Within the first time element The first time frame A subset of time slots corresponding to a predefined time slot block This indicates the number of all predefined time slot blocks. .

5. The multi-aircraft cooperative ad hoc network communication method for air search and rescue missions according to claim 2, characterized in that, The steps of using the configured self-organizing network communication system to perform resource scheduling and allocation for various aviation search and rescue missions include: All the collected aerial search and rescue missions are combined into an aerial search and rescue mission set, and the aerial search and rescue mission set is input into the configured self-organizing network communication system; The configured self-organizing network communication system divides the communication requirements of all the aviation search and rescue missions into multiple different configuration stages, and assigns each aviation search and rescue mission to the corresponding configuration stage. The configuration phase includes a setup phase, an operation phase, and a continuous phase. The setup phase corresponds to the control synchronization function group, the operation phase corresponds to the exploration and positioning function group, and the continuous phase corresponds to the dynamic search function group. The number of all legal time slots allocated to each of the aviation search and rescue missions in each of the configuration phases is determined using the configured ad hoc network communication system. The configured ad hoc network communication system is used to allocate all available and valid time slots in the operational phase to the corresponding air search and rescue missions in the continuous phase.

6. The multi-aircraft cooperative ad hoc network communication method for air search and rescue missions according to claim 5, characterized in that, The tasks performed during the establishment phase include: network access task, coarse synchronization task, fine synchronization task, and basic search task; The expression for the subset of legal time slots obtained during the establishment phase of the air search and rescue mission is: (4) in, Indicates the first The first time dimension The first phase of the establishment within the time slot allocation cycle A subset of legal time slots obtained from an aviation search and rescue mission. Indicates the first The first time dimension The set of legal time slots obtained during the setup phase within each time slot allocation cycle. , , Indicates the first The minimum number of legal time slots obtained for an air search and rescue mission Indicates the first The length of data that needs to be transmitted in an aerial search and rescue mission Indicates the first The effective payload length of each time slot Indicates rounding up; The tasks performed during the operation phase include: single exploration tasks, continuous exploration tasks, and location exploration tasks; The expression for the subset of legal time slots obtained during the operational phase of the air search and rescue mission is: (5) in, Indicates the first The first time dimension The first phase of operation within the time slot allocation cycle A subset of legal time slots obtained from an aviation search and rescue mission. Indicates the first The first time dimension A subset of occupied legal time slots during the operation phase within a time slot allocation cycle. , Indicates the first The first time dimension The set of legal time slots obtained during the operation phase within each time slot allocation cycle. Indicates the first The first time dimension A subset of idle legal time slots during the operation phase within a time slot allocation cycle. ; The tasks performed during the continuous phase include: voice tasks and status broadcasting tasks; The expression for the subset of legal time slots obtained during the sustained phase of the air search and rescue mission is: (6) in, Indicates the first The first time dimension The first phase of the continuous phase within the time slot allocation cycle A subset of legal time slots obtained from an aviation search and rescue mission. Indicates the first The first time dimension The set of legal time slots obtained during the continuous phase within a time slot allocation cycle. , Indicates the first The first time dimension The basic legal time slot subset for the continuous phase within a time slot allocation period ; The total set of legal time slots includes the set of legal time slots in the establishment phase, the set of legal time slots in the operation phase, and the set of legal time slots in the continuous phase.

7. The multi-aircraft cooperative ad hoc network communication method for air search and rescue missions according to claim 6, characterized in that, The first The first of the time elements The time slot interval between any two adjacent legal time slots in the duration phase within the time slot allocation period is represented as follows: , Indicates the first One legal time slot, Indicates the relationship with the first The next legal time slot adjacent to a legal time slot, , will the The first of the time elements The time slot interval threshold between any two adjacent legal time slots in the continuous phase within the time slot allocation period is expressed as follows: , , Indicates the first The first time dimension The maximum continuous waiting time allowed for a task during the continuous phase within a time slot allocation period. Indicates the first The first time dimension The duration of each legal time slot in the continuous phase within a time slot allocation cycle; when At that time, the task continuity requirement of the continuous phase is met; when At that time, the task continuity requirement of the continuous phase is not met.

8. The multi-aircraft cooperative ad hoc network communication method for air search and rescue missions according to claim 6, characterized in that, During the operation phase, the configured ad hoc network communication system allocates all the legal time slots using a uniform allocation strategy; The expression for allocating all the legal time slots using the uniform allocation strategy is as follows: (7) in, Indicates the first The first time dimension The first phase of operation within the time slot allocation cycle One legal time slot, Indicates the first The first time dimension The first phase of operation within the time slot allocation cycle An index of the legal time slots required for an aviation search and rescue mission. This indicates rounding down. Represents absolute value. Let represent the set of all left-hand elements that satisfy the condition on the right. It represents the set of natural numbers.

9. The multi-aircraft cooperative ad hoc network communication method for air search and rescue missions according to claim 6, characterized in that, During the operation phase, the configured self-organizing network communication system sets up multiple task instruction detection windows based on all the time slot allocation cycles, the locations of all the legal time slots, and the instruction issuance times of all the aviation search and rescue missions. Each task instruction detection window corresponds to one of the legal time slots. A time slot status decision function is introduced in each of the task instruction detection windows to detect the handover status of the current legal time slot; The expression for the time slot state decision function is: (8) in, Indicates the first The time slot status judgment function corresponding to the task instruction detection window; when When, it indicates the first If the task instruction detection window determines that the current valid time slot is an occupied valid time slot, then the configured ad hoc network communication system continues to execute the corresponding single exploration task, continuous exploration task, or location exploration task. when When, it indicates the first If the task instruction detection window determines that the current valid time slot is an idle valid time slot, the configured ad hoc network communication system will transfer the idle valid time slot to the continuous phase for executing the corresponding voice task or status broadcast task.

Images