Paired time division multiple access method and device in high dynamic scene

Abstract

The invention discloses a paired time division multiple access method and a paired time division multiple access device in a high dynamic scene. The method comprises the following steps of: mapping each link request into a vertex of a conflict graph; according to a primary conflict and secondary conflict judgment rule, adding undirected edges for vertex pairs with conflicts, and constructing a communication conflict graph; a TDPA time slot allocation problem is formalized into a minimum vertex coloring problem of a communication conflict graph; calculating to obtain a neighborhood cardinal number of each vertex through a global greedy coloring algorithm; carrying out descending sorting on the vertexes according to a neighborhood cardinal number; a minimum positive integer which is not used by a neighborhood vertex is distributed to each vertex in sequence to serve as a time slot, and an initial scheduling baseline is generated; updating the communication conflict graph based on the generated initial scheduling baseline and the current topology change information, and identifying failure vertexes; and re-coloring the failure vertexes through an incremental greedy coloring algorithm to obtain a new scheduling scheme. According to the invention, the problems of low channel utilization rate, poor real-time response, insufficient dynamic adaptability and the like in the prior art are solved.

Description

Technical Field

[0001] This invention relates to the field of communication technology, and specifically to a pairwise time-division multiple access method and apparatus for highly dynamic scenarios. Background Technology

[0002] Driven by the concepts of Network Centralized Systems (NCS) and Jointly Controlled Domains (JADC2), the future network environment is rapidly evolving towards high networking and intelligence. Scenarios such as the Internet of Things (IoT) and tactical communications are placing higher demands on the communication performance of data links. As the core backbone carrying data sensing, control, and collaborative communication, the data link needs to adapt to complex environments characterized by high dynamics, large node scale, and strong interference resistance. The quality of its media access control mechanism directly determines the overall communication efficiency. Traditional Time Division Multiple Access (TDMA) technology, due to its simple architecture and ease of implementation, has been widely used in various communication networks. To improve its flexibility, the industry has successively proposed improved technologies such as distributed time slot allocation schemes, CF-MAC protocols, and probabilistic contention mechanisms. Building on this, the Time Division Multiple Access (TDPA) framework significantly improves spatial reuse capabilities through link pairing and relative synchronization mechanisms. Zhan Kejun's team and others further optimized the latency and throughput characteristics of this mechanism in dynamic environments. Meanwhile, the researchers mapped the link scheduling problem to the minimum vertex coloring problem in graph theory and attempted to solve the conflict-free scheduling problem in highly dynamic scenarios through global heuristic algorithms or distributed coloring methods.

[0003] However, existing technologies still struggle to meet the stringent requirements of highly dynamic networks, presenting numerous unresolved issues. Traditional TDMA relies on a relatively static topology, and its predefined static time slot allocation ignores spatial reuse potential, resulting in low channel utilization. Furthermore, rigid scheduling cannot adapt to dynamic changes such as node movement and additions / removals, leading to an excessively high proportion of control messages and limited real-time communication capabilities. While distributed time slot allocation schemes and CF-MAC protocols improve flexibility to some extent, they still suffer from wasted idle time slots, high collision probabilities, and a lack of efficient concurrent scheduling capabilities for links. Although TDPA-related optimization mechanisms improve some performance, link scheduling faces NP-hard combinatorial optimization challenges in scenarios with highly dense nodes or rapidly changing conflicting links: while global heuristic graph coloring algorithms can generate high-quality scheduling schemes, their computational complexity increases polynomially with network size, making it difficult to meet millisecond-level real-time response requirements; distributed coloring methods are prone to local optima when information visibility is limited, and "coloring oscillations" can occur during continuous topology disturbances, leading to decreased scheduling stability and an inability to simultaneously achieve resource efficiency, dynamic adaptability, and real-time performance.

[0004] Therefore, there is an urgent need for a pairwise time-division multiple access method for highly dynamic scenarios to solve the problems of low channel utilization, poor real-time response, and insufficient dynamic adaptability of existing technologies. Summary of the Invention

[0005] To address this, the present invention provides a pairwise time-division multiple access method and apparatus for highly dynamic scenarios, which solves the problems of low channel utilization, poor real-time response, and insufficient dynamic adaptability of existing scheduling algorithms, and improves throughput and reduces latency under the premise of conflict-free transmission, adapting to scenarios with dense nodes and frequent topology changes.

[0006] To achieve the above objectives, the present invention provides the following technical solution: a pairwise time-division multiple access method for highly dynamic scenarios, characterized in that it includes:

[0007] Based on unidirectional communication link requests in a highly dynamic network, each link request is mapped to a vertex of a conflict graph; according to the rules for determining primary and secondary conflicts, undirected edges are added to the vertex pairs that have conflicts to construct a communication conflict graph; based on the communication conflict graph, the TDPA time slot allocation problem is formalized into the minimum vertex coloring problem of the communication conflict graph.

[0008] The neighborhood cardinality of each vertex in the communication conflict graph is calculated using a global greedy coloring algorithm. The vertices in the communication conflict graph are then sorted in descending order according to the neighborhood cardinality. Starting from the first vertex after sorting, the smallest positive integer not used by its neighboring vertices is assigned as a time slot to each vertex in turn to generate an initial scheduling baseline.

[0009] Based on the generated initial scheduling baseline and current topology change information, the communication conflict graph is updated, the failed vertices are identified, and the updated communication conflict graph is obtained. The failed vertices in the updated communication conflict graph are recolored using an incremental greedy coloring algorithm to obtain a new communication conflict graph, which is the new scheduling scheme.

[0010] As a preferred solution for pairwise time-division multiple access in highly dynamic scenarios, in the process of adding undirected edges to vertex pairs with conflicts according to the main conflict and secondary conflict determination rules, the main conflict determination rule is: if two link requests involve the same node participating in two different sending or receiving tasks at the same time, then a main conflict is determined to exist.

[0011] The collision determination rule is as follows: if two links request concurrent transmission and the signal-to-interference-plus-noise ratio of either receiving node is lower than the reliable demodulation threshold, then a collision is determined to exist.

[0012] As a preferred scheme for pairwise time-division multiple access methods in highly dynamic scenarios, the minimum vertex coloring problem of the communication conflict graph is: assigning a "color" representing a time slot to each vertex in the communication conflict graph, such that any two adjacent vertices have different colors, and minimizing the total number of colors used; the expression for the minimum vertex coloring problem of the communication conflict graph is:

[0013]

[0014] In the formula, C(v) represents the "color" of the time slot; v is the vertex; v c Let K be the set of vertices; K is the cardinality of the range, i.e., the total number of colors used.

[0015] As a preferred solution for a pairwise time-division multiple access method in a highly dynamic scenario, in the process of updating the communication conflict graph, identifying the failed vertices, and obtaining the updated communication conflict graph, based on the communication conflict graph, vertices and conflict edges corresponding to the current topology are added, vertices and conflict edges corresponding to the failed topology are deleted, the failed vertices are identified, and the updated communication conflict graph is obtained.

[0016] The failed vertices are divided into two categories: one is the newly added vertex corresponding to the new link request in the current topology; the other is the conflicting vertex with the same color in the previous cycle due to the addition of an edge in the communication conflict graph.

[0017] As a preferred scheme for pairwise time-division multiple access methods in highly dynamic scenarios, in the process of recoloring the failed vertices in the updated communication conflict graph using the incremental greedy coloring algorithm, the failed vertices are sorted in descending order according to the neighborhood cardinality in the updated communication conflict graph; after sorting, each failed vertex is recolored sequentially according to the greedy coloring logic to obtain the new communication conflict graph.

[0018] The present invention also provides a pairwise time-division multiple access device for high dynamic scenarios, based on the above-mentioned pairwise time-division multiple access method for high dynamic scenarios, comprising:

[0019] The communication conflict graph construction module is used to map each link request to a vertex of the conflict graph based on unidirectional communication link requests in a highly dynamic network; according to the rules for determining primary and secondary conflicts, it adds undirected edges to the vertex pairs with conflicts to construct the communication conflict graph; based on the communication conflict graph, the TDPA time slot allocation problem is formalized into the minimum vertex coloring problem of the communication conflict graph.

[0020] The initial scheduling baseline generation module is used to calculate the neighborhood cardinality of each vertex in the communication conflict graph using a global greedy coloring algorithm; sort the vertices in the communication conflict graph in descending order according to the neighborhood cardinality; starting from the first vertex after sorting, assign the smallest positive integer not used by its neighboring vertices as a time slot to each vertex in turn to generate the initial scheduling baseline.

[0021] The new scheduling scheme generation module is used to update the communication conflict graph based on the generated initial scheduling baseline and current topology change information, identify the failed vertices, and obtain the updated communication conflict graph; and recolor the failed vertices in the updated communication conflict graph using an incremental greedy coloring algorithm to obtain a new communication conflict graph, which is the new scheduling scheme.

[0022] As a preferred solution for pairwise time-division multiple access devices in highly dynamic scenarios, in the communication conflict graph construction module, during the process of adding undirected edges to vertex pairs with conflicts according to the main conflict and secondary conflict determination rules, the main conflict determination rule is: if two link requests involve the same node participating in two different sending or receiving tasks at the same time, then it is determined that there is a main conflict.

[0023] The collision determination rule is as follows: if two links request concurrent transmission and the signal-to-interference-plus-noise ratio of either receiving node is lower than the reliable demodulation threshold, then a collision is determined to exist.

[0024] As a preferred solution for paired time-division multiple access devices in highly dynamic scenarios, the minimum vertex coloring problem of the communication conflict graph construction module is: assigning a "color" representing a time slot to each vertex in the communication conflict graph, such that any two adjacent vertices have different colors, and minimizing the total number of colors used; the expression for the minimum vertex coloring problem of the communication conflict graph is:

[0025]

[0026] In the formula, C(v) represents the "color" of the time slot; v is the vertex; v c Let K be the set of vertices; K is the cardinality of the range, i.e., the total number of colors used.

[0027] As a preferred solution for a pairwise time-division multiple access device in a highly dynamic scenario, in the process of updating the communication conflict graph, identifying the failed vertices, and obtaining the updated communication conflict graph, the module adds vertices and conflict edges corresponding to the current topology, deletes vertices and conflict edges corresponding to the failed topology, identifies the failed vertices, and obtains the updated communication conflict graph based on the communication conflict graph.

[0028] The failed vertices are divided into two categories: one is the newly added vertex corresponding to the new link request in the current topology; the other is the conflicting vertex with the same color in the previous cycle due to the addition of an edge in the communication conflict graph.

[0029] As a preferred solution for pairwise time-division multiple access devices in highly dynamic scenarios, in the new scheduling scheme generation module, during the process of recoloring the failed vertices in the updated communication conflict graph using the incremental greedy coloring algorithm, the failed vertices are sorted in descending order according to the neighborhood cardinality in the updated communication conflict graph; after sorting, each failed vertex is recolored sequentially according to the greedy coloring logic to obtain the new communication conflict graph.

[0030] The present invention has the following advantages:

[0031] This invention is based on unidirectional communication link requests in highly dynamic networks, mapping each link request to a vertex in a conflict graph. According to the rules for determining primary and secondary conflicts, undirected edges are added to conflicting vertex pairs to construct a communication conflict graph. Based on this communication conflict graph, the TDPA time slot allocation problem is formalized as a minimum vertex coloring problem. A global greedy coloring algorithm is used to calculate the neighborhood cardinality of each vertex in the communication conflict graph. The vertices in the communication conflict graph are sorted in descending order according to the neighborhood cardinality. Starting from the first sorted vertex, the smallest positive integer not used by its neighboring vertices is assigned as a time slot to each vertex, generating an initial scheduling baseline. Based on the generated initial scheduling baseline and current topology change information, the communication conflict graph is updated, identifying failed vertices to obtain an updated communication conflict graph. An incremental greedy coloring algorithm is used to recolor the failed vertices in the updated communication conflict graph to obtain a new communication conflict graph, which is the new scheduling scheme. This invention constructs a dynamic graph coloring model and adopts a hybrid graph coloring scheduling algorithm. It generates a high-quality initial scheduling baseline with the help of a global greedy strategy and quickly repairs local conflicts caused by topology changes with an incremental greedy strategy. While ensuring conflict-free transmission, it significantly improves channel space reuse and network throughput, significantly reduces end-to-end latency and scheduling update time, and is unaffected by network expansion. It has strong adaptability and stability in highly dynamic scenarios with dense nodes and frequent topology changes. Attached Figure Description

[0032] To more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings in the following description are merely exemplary, and those skilled in the art can derive other embodiments based on the provided drawings without creative effort.

[0033] The structures, proportions, sizes, etc. illustrated in this specification are only for the purpose of assisting those skilled in the art in understanding and reading the content disclosed herein, and are not intended to limit the conditions under which the present invention can be implemented. Therefore, they have no substantial technical significance. Any modifications to the structure, changes in the proportions, or adjustments to the size, without affecting the effects and objectives that the present invention can produce, should still fall within the scope of the technical content disclosed in the present invention.

[0034] Figure 1 This is a flowchart illustrating a pairwise time-division multiple access method in a highly dynamic scenario provided in Embodiment 1 of the present invention;

[0035] Figure 2 This is a schematic diagram of the TDPA principle in a pairwise time division multiple access method for highly dynamic scenarios provided in Embodiment 1 of the present invention;

[0036] Figure 3 This is a schematic diagram comparing the latency of the global greedy algorithm and the incremental greedy algorithm in one possible embodiment of Embodiment 1 of the present invention;

[0037] Figure 4 This is a schematic diagram comparing the throughput of TDPA and TDMA networks under a single static topology in one possible embodiment of Embodiment 1 of the present invention;

[0038] Figure 5 This is a schematic diagram comparing the end-to-end latency of TDPA and TDMA under a single static topology in one possible embodiment of Embodiment 1 of the present invention;

[0039] Figure 6 This is a schematic diagram comparing the network throughput of TDPA under single and dynamic topologies in one possible embodiment of Embodiment 1 of the present invention;

[0040] Figure 7 This is a schematic diagram comparing the end-to-end latency of TDPA under single and dynamic topologies in one possible embodiment of Embodiment 1 of the present invention;

[0041] Figure 8 This is a schematic diagram of the architecture of a pairwise time-division multiple access device in a high-dynamic scenario provided in Embodiment 2 of the present invention. Detailed Implementation

[0042] The following specific embodiments illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0043] Example 1

[0044] See Figure 1 Embodiment 1 of the present invention provides a pairwise time-division multiple access method in a highly dynamic scenario, comprising the following steps:

[0045] S1. Based on the unidirectional communication link request in a highly dynamic network, each link request is mapped to a vertex of the conflict graph; according to the rules for determining primary and secondary conflicts, undirected edges are added to the vertex pairs that have conflicts to construct a communication conflict graph; based on the communication conflict graph, the TDPA time slot allocation problem is formalized into the minimum vertex coloring problem of the communication conflict graph.

[0046] S2. Calculate the neighborhood cardinality of each vertex in the communication conflict graph using a global greedy coloring algorithm; sort the vertices in the communication conflict graph in descending order according to the neighborhood cardinality; starting from the first vertex after sorting, assign the smallest positive integer not used by its neighboring vertices as a time slot to each vertex in turn, and generate the initial scheduling baseline.

[0047] S3. Based on the generated initial scheduling baseline and current topology change information, update the communication conflict graph, identify the failed vertices, and obtain the updated communication conflict graph; recolor the failed vertices in the updated communication conflict graph using an incremental greedy coloring algorithm to obtain a new communication conflict graph, which is the new scheduling scheme.

[0048] In this embodiment, under the TDPA communication mechanism applicable to a four-node network, network communication is organized based on nodes: each pair of nodes is configured with independent uplink and downlink. The uplink is used by each node to transmit data to the aggregation node S, while the downlink is used by the aggregation node S to distribute instructions or requests to other nodes. Each channel is scheduled to discrete and random time slots to avoid communication overlap. Nodes can explicitly send or receive data with neighboring nodes within a specific time window according to a preset session schedule, ensuring the orderliness of communication.

[0049] like Figure 2 As shown, TDPA allocates corresponding time slots to different links. In scenarios with dense nodes and high concurrency of communication requests, when the hop sequences of multiple different links overlap at a certain absolute time point, if these links are spatially adjacent, their concurrent transmission will fail due to co-channel interference or node half-duplex constraints. Therefore, a higher-level scheduling mechanism needs to be designed to solve the TDPA time slot scheduling problem:

[0050] Conflict-free: Any two communication link requests that have a physical conflict cannot be allocated to the same global time slot for activation.

[0051] Efficiency: Under the premise of satisfying the non-conflict requirement, as many concurrent communication links as possible should be scheduled in each time slot, so as to minimize the total number of time slots (i.e., scheduling frame length) required to complete all requests.

[0052] In this embodiment, in step S1, based on the unidirectional communication link request in the high dynamic network, each link request is mapped to a vertex of the conflict graph; according to the rules for determining primary and secondary conflicts, undirected edges are added to the vertex pairs that have conflicts to construct a communication conflict graph; based on the communication conflict graph, the TDPA time slot allocation problem is formalized into the minimum vertex coloring problem of the communication conflict graph.

[0053] Specifically, the process begins by comprehensively collecting the unidirectional communication requirements between all nodes in the high-dynamic network, forming a set of link requests. Each link request uniquely corresponds to a vertex in the conflict graph, thus mapping physical communication requirements to graph vertices. Next, for any two link requests corresponding to vertices, a dual conflict determination rule is used to decide whether to add an edge. Undirected edges are added for both types of conflicts to represent incompatibility. Finally, this conflict graph transforms TDPA time slot allocation into a minimum vertex coloring problem. This involves assigning colors to vertices to ensure that adjacent vertices have different colors and that the total number of colors is minimized, achieving conflict-free time slot reuse.

[0054] In this embodiment, the time slot scheduling algorithm is transformed into a graph coloring problem, and a communication conflict graph, denoted as G, is constructed based on the scheduling entities and constraint relationships in the network. c =(V c E c The chromatic number of graph G is denoted by χ(G), and satisfies the following constraint: for any edge (u,v)∈E in the graph, the colors assigned to its two endpoints must be different, i.e., C(u)≠C(v). Each unidirectional communication link request to be scheduled in the network is denoted by l. i =(S i D i The request is uniquely mapped to a vertex v in the conflict graph. i ∈V c As for V c Any two distinct vertices V in i and V j If and only if their corresponding physical links l i and l j When concurrent transmission in the same time slot is not possible, add an undirected edge (v) between them. i ,v j )∈E c .

[0055] In the process of adding undirected edges to a pair of vertices that are in conflict according to the rules for determining primary and secondary conflicts, the rule for determining primary conflict is: if two link requests involve the same node participating in two different sending or receiving tasks at the same time, then a primary conflict is determined to exist.

[0056] Specifically, this is caused by the "half-duplex" constraint of communication nodes, meaning that a node cannot send and receive simultaneously, nor can it participate in two different sending or receiving tasks at the same time. If l i The request is for S i →D i Request l j For S j →D j Then when At that time, there is a primary conflict between the two.

[0057] The collision determination rule is as follows: if two links request concurrent transmission and the signal-to-interference-plus-noise ratio of either receiving node is lower than the reliable demodulation threshold, then a collision is determined to exist.

[0058] Specifically, this is caused by co-channel interference. When multiple links transmit concurrently, a receiving node will be subject to cumulative interference from all other concurrent transmitting nodes besides its intended signal source. If this cumulative interference causes the receiving node's signal-to-interference-plus-noise ratio (SINR) to fall below the threshold γ required for reliable demodulation... th If so, then a secondary conflict is determined to exist.

[0059] Assuming request l i (from S) i To D i ) and l j (from S) j To D j Concurrency, if S j For D i Interference caused D i The signal-to-interference-plus-noise ratio (SINR) at the location is below the threshold γ th If the two are in conflict, then the following conditions must be met:

[0060]

[0061] In the formula, P is the transmit power, G is the channel gain, and N0 is the noise power.

[0062] In the process of constructing a communication conflict graph, all link pairs (l i ,l j Perform the pairwise checks for the primary and secondary conflicts mentioned above.

[0063] To solve the minimum vertex coloring problem of a graph while satisfying the conflict-free constraint, we assign a "color" C(v) to each vertex v in the graph to represent a time slot, such that any two adjacent vertices have different colors, and minimize the total number of colors used.

[0064]

[0065] In the formula, C(v) represents the "color" of the time slot; v is the vertex; v c Let K be the set of vertices; K is the cardinality of the range, i.e., the total number of colors used.

[0066] The constraints ensure that any two vertices connected by an edge are assigned different colors, guaranteeing the conflict-free nature of the scheduling scheme.

[0067] In this embodiment, in step S2, the neighborhood cardinality of each vertex in the communication conflict graph is calculated using a global greedy coloring algorithm; the vertices in the communication conflict graph are sorted in descending order according to the neighborhood cardinality; starting from the first vertex after sorting, the smallest positive integer not used by its neighboring vertices is assigned as a time slot for each vertex in turn to generate an initial scheduling baseline.

[0068] Specifically, the global greedy coloring algorithm performs scheduling calculations on the complete conflict graph during the initial network deployment phase. First, it traverses all vertices in the conflict graph, calculating the neighborhood cardinality of each vertex. This value reflects the conflict complexity of link requests; a higher cardinality indicates that the link conflicts with more links, requiring priority allocation of time slots to reduce subsequent conflicts. Then, vertices are sorted from largest to smallest neighborhood cardinality. If cardins are the same, a deterministic sort is performed based on the source node ID or destination node ID involved in the link, avoiding scheduling quality fluctuations caused by random sorting. After sorting, coloring begins sequentially from the first vertex: for the current vertex, the color set of all its colored neighboring vertices is collected. The smallest value not appearing in this set is selected from the positive integer sequence as the color (corresponding time slot) of the current vertex, ensuring no conflict with its neighbors. After all vertices are colored, the resulting color allocation scheme forms the initial scheduling baseline, providing a basis for time slot allocation in the network.

[0069] In this embodiment, in step S3, based on the generated initial scheduling baseline and the current topology change information, the communication conflict graph is updated, the failed vertices are identified, and the updated communication conflict graph is obtained; the failed vertices in the updated communication conflict graph are recolored using an incremental greedy coloring algorithm to obtain a new communication conflict graph, which is the new scheduling scheme.

[0070] Specifically, the first step is to perform conflict graph updates and fail vertex identification. This is based on the topology change information ΔG. c Update the conflict graph G from the previous cycle. cThe conflict graph G′ for the current cycle is obtained. c The algorithm then identifies all "failed" vertices that need recoloring and stores them in a set Q. Failed vertices fall into two main categories: the first category consists of vertices newly added during topological changes; the second category consists of vertices whose colors conflict with existing vertices due to newly added edges (u, v) in the topology, i.e., C(u) = C(v). For the second category, to reduce the disturbance to the existing scheme during the repair process, the cardinality of the neighborhoods of u and v is usually chosen. The smaller one is determined to be the invalid vertex.

[0071] Then, a local recoloring is performed, targeting the vertices in Q. The colors of these invalid vertices are reset to 0. Only vertices within this small set are recolored according to their position in the updated conflict graph G. c The neighborhood cardinality in ' is sorted in descending order. According to this local sorting, a greedy coloring logic is executed for each invalid vertex, that is, assigning it the minimum available color that does not conflict with all its neighbors, regardless of whether the neighbors are in Q.

[0072] After the local recoloring is completed, the part of the original scheduling scheme C corresponding to Q has been updated, thus forming a new scheduling scheme C' that adapts to the network topology change.

[0073] In one possible embodiment, a simulation verification example is provided as follows:

[0074] To verify the effectiveness and advantages of the proposed TDPA protocol, simulations were conducted on a network simulation platform to verify the computational performance of the time slot allocation algorithm, the communication performance of the protocol, and its adaptability under dynamic topology.

[0075] The main parameter configurations are shown in Table 1. The network scenarios are divided into two types: static topology transformation and dynamic topology transformation. Static topology uses a fully connected mesh structure to ensure baseline connectivity between any nodes. Dynamic topology is constructed by simulating four typical events: node addition, node removal, link establishment, and link interruption. Since the target nodes in traffic generation are randomly selected, the end-to-end latency and throughput metrics of each node are expected to show statistical differences.

[0076] parameter Value Node size / number 56 Time slot length / s 0.1 Packet generation interval / s 0.1 Topology Scene Static topology / Dynamic topology

[0077] Table 1 Simulation parameter configuration

[0078] To evaluate the computational efficiency of the incremental greedy graph coloring algorithm in the proposed TDPA protocol, its execution time is compared with that of the traditional global greedy algorithm in dynamic topology scenarios. In the simulation, 10 sets of dynamic topology sequences containing the four transformation events mentioned above are randomly generated for different node sizes.

[0079] like Figure 3As shown, the average runtime of the two algorithms under different network sizes is illustrated. Simulation results show that the runtime of the global greedy algorithm exhibits a significant linear growth trend with the increase of the number of nodes. In contrast, the runtime of the incremental greedy algorithm increases much more gradually. Although the incremental algorithm has a slightly higher runtime due to the overhead of initial construction and state maintenance when the network size is small (N=10), its advantage of only needing to update locally affected nodes becomes increasingly prominent as the network size increases. Furthermore, the runtime difference curve in the figure closely matches the trend of the global greedy algorithm, proving that the computational overhead of the incremental greedy algorithm is basically unaffected by the expansion of the network size.

[0080] To evaluate protocol performance, network throughput and end-to-end latency of TDPA and TDMA protocols were compared under the same single static topology and network parameter configuration.

[0081] like Figure 4 The figure shows a comparison of the data throughput curves for the two protocols. The results indicate that the network throughput of each node under the TDPA protocol is significantly higher than that under the TDMA protocol, meaning that the data transmission capability of TDMA is weaker than that of TDPA. This is consistent with the theoretical basis of the two time slot allocation methods: within the same time slot, TDPA can achieve far more collision-free transmission links than TDMA. TDPA, based on a distributed time slot allocation mechanism of "node pairs," can maximize the spatial reuse of network links, thereby achieving higher network capacity.

[0082] like Figure 5 The figure shows a comparison of the end-to-end delays of the two protocols. Figure 5 It is known that in TDMA networks, data packets must wait in a buffer for their fixed transmission slots, leading to significant queuing time accumulation. In contrast, the TDPA protocol allows nodes to obtain transmission opportunities more frequently, greatly reducing the waiting time for data packets. Experimental results show that the TDPA protocol, through its efficient slot resource allocation mechanism, can significantly improve network throughput and reduce end-to-end latency.

[0083] To verify the robustness of the TDPA protocol in dynamic network environments, the network throughput and end-to-end latency performance were further compared under single static and dynamic topologies. Figure 6 and Figure 7 As shown, in both network scenarios, the end-to-end latency and network throughput curves of the TDPA protocol highly overlap, demonstrating the TDPA protocol's good robustness to network topology changes. It is worth noting that the performance curve under dynamic topology is even slightly better than that under static topology in some periods. This phenomenon can be attributed to the fact that some topology changes may accidentally simplify local network connectivity, reducing channel contention and thus leading to better network performance.

[0084] In summary, the TDPA protocol not only outperforms the traditional TDMA protocol in communication performance, but also demonstrates strong adaptability and robustness in its time slot allocation mechanism when facing dynamically changing network environments, enabling it to maintain consistently high network performance.

[0085] The application scenarios of this invention are as follows:

[0086] In tactical communication scenarios, this invention adapts to highly dynamic topologies with rapid movement of combat units and frequent additions and subtractions of nodes through a dynamic graph coloring model. Its hybrid scheduling algorithm not only ensures link conflicts under strong electromagnetic interference and guarantees conflict-free transmission of combat commands and reconnaissance data, but also improves channel reuse rate to support multi-domain collaborative operations. Furthermore, the incremental update mechanism meets the real-time requirements of tactical response.

[0087] In UAV ad hoc networks, this invention addresses the problem of rapid link switching caused by UAV formation maneuvers. It generates an initial scheduling baseline through a global greedy algorithm to ensure spatial reuse of dense nodes, and uses an incremental coloring algorithm to quickly repair local conflicts caused by topological disturbances, avoiding "coloring oscillations" to stabilize the transmission of mission coordination data and improve the communication reliability of the formation when performing reconnaissance and inspection missions.

[0088] In industrial IoT scenarios, this invention adapts to the dynamic topology formed by the movement of AGV robots and the dynamic access of sensors in the workshop. Its conflict graph construction mechanism accurately identifies the half-duplex constraints and co-frequency interference of equipment communication. Through efficient time slot allocation, it reduces the end-to-end latency of production data uploading and control command issuance, supporting real-time collaboration under high-density equipment deployment in smart manufacturing.

[0089] In emergency communication scenarios, this invention addresses the topological uncertainty of temporary networks at disaster sites by rapidly generating a scheduling baseline to enable immediate access between rescue terminals and command centers. Through a local recoloring mechanism, it adapts to the dynamic addition or removal of nodes, maximizing communication throughput under limited channel resources and ensuring real-time transmission of disaster data and efficient issuance of rescue instructions.

[0090] In the context of vehicle-to-everything (V2X) scenarios, this invention addresses the problem of frequent link disconnections caused by high-speed vehicle movement. Its conflict graph model accurately depicts the interference relationship between vehicle-to-vehicle communication. The combination of global and incremental algorithms not only improves the channel utilization rate of dense traffic flow on roads, but also ensures low-latency transmission of autonomous driving decision data through millisecond-level scheduling updates, supporting real-time collaboration between vehicles and between vehicles and roadside units.

[0091] It should be noted that the method of this disclosure embodiment can be executed by a single device, such as a computer or server. The method of this embodiment can also be applied to a distributed scenario, where multiple devices cooperate to complete the task. In such a distributed scenario, one of these devices may execute only one or more steps of the method of this disclosure embodiment, and the multiple devices will interact with each other to complete the method described.

[0092] It should be noted that the above description describes some embodiments of this disclosure. Other embodiments are within the scope of the appended claims. In some cases, the actions or steps recorded in the claims can be performed in a different order than that shown in the above embodiments and still achieve the desired result. Furthermore, the processes depicted in the drawings do not necessarily require a specific or sequential order to achieve the desired result. In some embodiments, multitasking and parallel processing are also possible or may be advantageous.

[0093] Example 2

[0094] See Figure 8 Embodiment 2 of the present invention also provides a pairwise time-division multiple access device for high dynamic scenarios, comprising:

[0095] The communication conflict graph construction module 001 is used to map each link request as a vertex of the conflict graph based on the unidirectional communication link request in the high dynamic network; according to the main conflict and secondary conflict determination rules, it adds undirected edges to the vertex pairs with conflict to construct the communication conflict graph; based on the communication conflict graph, the TDPA time slot allocation problem is formalized into the minimum vertex coloring problem of the communication conflict graph.

[0096] The initial scheduling baseline generation module 002 is used to calculate the neighborhood cardinality of each vertex in the communication conflict graph using a global greedy coloring algorithm; sort the vertices in the communication conflict graph in descending order according to the neighborhood cardinality; starting from the first vertex after sorting, assign the smallest positive integer not used by its neighboring vertices as a time slot to each vertex in turn, thereby generating the initial scheduling baseline.

[0097] The new scheduling scheme generation module 003 is used to update the communication conflict graph based on the generated initial scheduling baseline and the current topology change information, identify the failed vertices, and obtain the updated communication conflict graph; and to recolor the failed vertices in the updated communication conflict graph using an incremental greedy coloring algorithm to obtain a new communication conflict graph, which is the new scheduling scheme.

[0098] In this embodiment, in the communication conflict graph construction module 001, during the process of adding undirected edges to the vertex pairs that have conflicts according to the main conflict and secondary conflict determination rules, the main conflict determination rule is: if two link requests involve the same node participating in two different sending or receiving tasks at the same time, then it is determined that there is a main conflict.

[0099] The collision determination rule is as follows: if two links request concurrent transmission and the signal-to-interference-plus-noise ratio of either receiving node is lower than the reliable demodulation threshold, then a collision is determined to exist.

[0100] In this embodiment, in the communication conflict graph construction module 001, the minimum vertex coloring problem of the communication conflict graph is: assigning a "color" representing a time slot to each vertex in the communication conflict graph, such that any two adjacent vertices have different colors, and minimizing the total number of colors used; the expression for the minimum vertex coloring problem of the communication conflict graph is:

[0101]

[0102] In the formula, C(v) represents the "color" of the time slot; v is the vertex; v c Let K be the set of vertices; K is the cardinality of the range, i.e., the total number of colors used.

[0103] In this embodiment, the new scheduling scheme generation module 003 updates the communication conflict graph, identifies the failed vertices, and obtains the updated communication conflict graph. Based on the communication conflict graph, it adds vertices and conflict edges corresponding to the current topology, deletes vertices and conflict edges corresponding to the failed topology, identifies the failed vertices, and obtains the updated communication conflict graph.

[0104] The failed vertices are divided into two categories: one is the newly added vertex corresponding to the new link request in the current topology; the other is the conflicting vertex with the same color in the previous cycle due to the addition of an edge in the communication conflict graph.

[0105] In this embodiment, in the new scheduling scheme generation module 003, during the process of recoloring the failed vertices in the updated communication conflict graph using the incremental greedy coloring algorithm, the failed vertices are sorted in descending order according to the neighborhood cardinality in the updated communication conflict graph; after sorting, each failed vertex is recolored sequentially according to the greedy coloring logic to obtain the new communication conflict graph.

[0106] It should be noted that the information interaction and execution process between the modules of the above system are based on the same concept as the method embodiment in Embodiment 1 of this application, and the resulting technical effects are the same as those in the method embodiment of this application. For details, please refer to the description in the method embodiment shown above in this application, and it will not be repeated here.

[0107] Example 3

[0108] Embodiment 3 of the present invention provides a non-transitory computer-readable storage medium storing program code for a pairwise time-division multiple access method in a highly dynamic scenario. The program code includes instructions for executing the pairwise time-division multiple access method in a highly dynamic scenario according to Embodiment 1 or any possible implementation thereof.

[0109] Computer-readable storage media can be any available medium that a computer can access, or a data storage device such as a server or data center that integrates one or more available media. The available medium can be magnetic media (e.g., floppy disks, hard disks, magnetic tapes), optical media (e.g., DVDs), or semiconductor media (e.g., solid-state drives, SSDs).

[0110] Example 4

[0111] Embodiment 4 of the present invention provides an electronic device, including: a memory and a processor;

[0112] The processor and the memory communicate with each other via a bus; the memory stores program instructions that can be executed by the processor, and the processor can execute a pairwise time-division multiple access method in a high-dynamic scenario by calling the program instructions.

[0113] Specifically, a processor can be implemented in hardware or software. When implemented in hardware, the processor can be a logic circuit, an integrated circuit, etc. When implemented in software, the processor can be a general-purpose processor that reads software code stored in memory. This memory can be integrated into the processor or located outside the processor and exist independently.

[0114] In the above embodiments, implementation can be achieved, in whole or in part, through software, hardware, firmware, or any combination thereof. When implemented in software, it can be implemented, in whole or in part, as a computer program product. The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, all or part of the processes or functions described in the embodiments of the present invention are generated. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable system. The computer instructions can be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another. For example, the computer instructions can be transmitted from one website, computer, server, or data center to another via wired (e.g., coaxial cable, fiber optic, digital subscriber line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) means.

[0115] It is obvious to those skilled in the art that the modules or steps of the present invention described above can be implemented using general-purpose computing systems. They can be centralized on a single computing system or distributed across a network of multiple computing systems. Optionally, they can be implemented using program code executable by a computing system, thereby storing them in a storage system for execution by the computing system. In some cases, the steps shown or described can be performed in a different order than those presented herein, or they can be fabricated as separate integrated circuit modules, or multiple modules or steps can be fabricated as a single integrated circuit module. Thus, the present invention is not limited to any particular combination of hardware and software.

[0116] Although the present invention has been described in detail above with general descriptions and specific embodiments, modifications or improvements can be made to it, which will be obvious to those skilled in the art. Therefore, all such modifications or improvements made without departing from the spirit of the present invention fall within the scope of protection claimed by the present invention.

Claims

1. A pairwise time-division multiple access method for highly dynamic scenarios, characterized in that, include: Based on unidirectional communication link requests in highly dynamic networks, each link request is mapped to a vertex of a conflict graph; According to the rules for determining primary and secondary conflicts, undirected edges are added to the vertex pairs with conflicts to construct a communication conflict graph; based on the communication conflict graph, the TDPA time slot allocation problem is formalized into the minimum vertex coloring problem of the communication conflict graph. The neighborhood cardinality of each vertex in the communication conflict graph is calculated using a global greedy coloring algorithm. The vertices in the communication conflict graph are then sorted in descending order according to the neighborhood cardinality. Starting from the first vertex after sorting, the smallest positive integer not used by its neighboring vertices is assigned as a time slot to each vertex in turn to generate an initial scheduling baseline. Based on the generated initial scheduling baseline and current topology change information, the communication conflict graph is updated, the failed vertices are identified, and the updated communication conflict graph is obtained. The failed vertices in the updated communication conflict graph are recolored using an incremental greedy coloring algorithm to obtain a new communication conflict graph, which is the new scheduling scheme.

2. The pairwise time-division multiple access method for highly dynamic scenarios according to claim 1, characterized in that, In the process of adding undirected edges to vertices that have conflicts according to the rules for determining primary and secondary conflicts, the rule for determining primary conflicts is: if two link requests involve the same node participating in two different sending or receiving tasks at the same time, then a primary conflict is determined to exist. The collision determination rule is as follows: if two links request concurrent transmission and the signal-to-interference-plus-noise ratio of either receiving node is lower than the reliable demodulation threshold, then a collision is determined to exist.

3. The pairwise time-division multiple access method for highly dynamic scenarios according to claim 2, characterized in that, The minimum vertex coloring problem of the communication conflict graph is: assign a "color" representing a time slot to each vertex in the communication conflict graph such that any two adjacent vertices have different colors, and minimize the total number of colors used; the expression of the minimum vertex coloring problem of the communication conflict graph is: In the formula, C(v) represents the "color" of the time slot; v is the vertex; v c Let K be the set of vertices; K is the cardinality of the range, i.e., the total number of colors used.

4. The pairwise time-division multiple access method for high dynamic scenarios according to claim 3, characterized in that, In the process of updating the communication conflict graph, identifying the failed vertices, and obtaining the updated communication conflict graph, based on the communication conflict graph, vertices and conflict edges corresponding to the current topology are added, vertices and conflict edges corresponding to the failed topology are deleted, the failed vertices are identified, and the updated communication conflict graph is obtained. The failed vertices are divided into two categories: one is the newly added vertex corresponding to the new link request in the current topology; the other is the conflicting vertex with the same color in the previous cycle due to the addition of an edge in the communication conflict graph.

5. The pairwise time-division multiple access method for highly dynamic scenarios according to claim 4, characterized in that, During the process of recoloring the failed vertices in the updated communication conflict graph using the incremental greedy coloring algorithm, the failed vertices are sorted in descending order according to the neighborhood cardinality in the updated communication conflict graph. After sorting, each invalid vertex is recolored sequentially according to the greedy coloring logic to obtain the new communication conflict graph.

6. A pairwise time-division multiple access device for high dynamic scenarios, employing the pairwise time-division multiple access method for high dynamic scenarios as described in any one of claims 1-5, characterized in that, include: The communication conflict graph construction module is used to map each link request as a vertex in the conflict graph based on unidirectional communication link requests in a highly dynamic network. According to the rules for determining primary and secondary conflicts, undirected edges are added to the vertex pairs with conflicts to construct a communication conflict graph; based on the communication conflict graph, the TDPA time slot allocation problem is formalized into the minimum vertex coloring problem of the communication conflict graph. The initial scheduling baseline generation module is used to calculate the neighborhood cardinality of each vertex in the communication conflict graph using a global greedy coloring algorithm; sort the vertices in the communication conflict graph in descending order according to the neighborhood cardinality; starting from the first vertex after sorting, assign the smallest positive integer not used by its neighboring vertices as a time slot to each vertex in turn to generate the initial scheduling baseline. The new scheduling scheme generation module is used to update the communication conflict graph based on the generated initial scheduling baseline and current topology change information, identify the failed vertices, and obtain the updated communication conflict graph; and recolor the failed vertices in the updated communication conflict graph using an incremental greedy coloring algorithm to obtain a new communication conflict graph, which is the new scheduling scheme.

7. The pairwise time-division multiple access device for high dynamic scenarios according to claim 6, characterized in that, In the communication conflict graph construction module, during the process of adding undirected edges to the vertex pairs that have conflicts according to the main conflict and secondary conflict determination rules, the main conflict determination rule is: if two link requests involve the same node participating in two different sending or receiving tasks at the same time, then it is determined that there is a main conflict. The collision determination rule is as follows: if two links request concurrent transmission and the signal-to-interference-plus-noise ratio of either receiving node is lower than the reliable demodulation threshold, then a collision is determined to exist.

8. A pairwise time-division multiple access device for high dynamic scenarios according to claim 7, characterized in that, In the communication conflict graph construction module, the minimum vertex coloring problem of the communication conflict graph is: assigning a "color" representing a time slot to each vertex in the communication conflict graph, such that any two adjacent vertices have different colors, and minimizing the total number of colors used; the expression for the minimum vertex coloring problem of the communication conflict graph is: In the formula, C(v) represents the "color" of the time slot; v is the vertex; v c Let K be the set of vertices; K is the cardinality of the range, i.e., the total number of colors used.

9. A pairwise time-division multiple access device for high dynamic scenarios according to claim 8, characterized in that, In the new scheduling scheme generation module, during the process of updating the communication conflict graph, identifying the failed vertices, and obtaining the updated communication conflict graph, based on the communication conflict graph, vertices and conflict edges corresponding to the current topology are added, vertices and conflict edges corresponding to the failed topology are deleted, the failed vertices are identified, and the updated communication conflict graph is obtained. The failed vertices are divided into two categories: one is the newly added vertex corresponding to the new link request in the current topology; the other is the conflicting vertex with the same color in the previous cycle due to the addition of an edge in the communication conflict graph.

10. A pairwise time-division multiple access device for high dynamic scenarios according to claim 9, characterized in that, In the new scheduling scheme generation module, during the process of recoloring the failed vertices in the updated communication conflict graph using the incremental greedy coloring algorithm, the failed vertices are sorted in descending order according to the neighborhood cardinality in the updated communication conflict graph. After sorting, each invalid vertex is recolored sequentially according to the greedy coloring logic to obtain the new communication conflict graph.

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