Cooperative retransmission method and system based on dynamic self-organizing tdma

Abstract

The present disclosure provides a dynamic self-organizing TDMA-based cooperative retransmission method and system, comprising: a source node device sending an RTC data packet to a target node device in a second data transmission time slot if the number of communication failures of sending a communication data packet to the target node device exceeds a preset number threshold in a first data transmission time slot; the target node device sending a CTC data packet to the source node device; a cooperative node device obtaining the RTC data packet and the CTC data packet by listening to the communication data of the source node device; the source node device sending a communication data packet to the target node device in a third data transmission time slot; the cooperative node device sending a communication data packet to the target node device in a preset transmission time slot; the target node device sending a data confirmation signal to the source node device; and the source node device determining that the cooperative transmission of the communication data packet is successful after receiving the data confirmation signal. Thus, the retransmission success rate after link interruption is effectively improved.

Description

TECHNICAL FIELD

[0001] Embodiments of the present disclosure relate to the field of wireless communication technology, in particular, to a dynamic self-organizing TDMA-based cooperative retransmission method and system. BACKGROUND

[0002] The UAV cluster self-organizing network is a network with high flexibility and self-adaptability, which has the characteristics of fast node movement speed, complex and changeable link environment, large network range, and dense node distribution. In this case, the link between nodes often breaks down.

[0003] In the prior art, when the communication link between node devices breaks down, the communication link is usually reset, such as selecting the communication link with other node devices to transmit the current data packet. This method will affect the communication data transmission between other node devices, resulting in loss of the current data packet. SUMMARY

[0004] The embodiments described herein provide a dynamic self-organizing TDMA-based cooperative retransmission method and system, which overcomes the above problems.

[0005] In a first aspect, according to the content of the present disclosure, a dynamic self-organizing TDMA-based cooperative retransmission method is provided, comprising:

[0006] If the number of communication failures of the source node device in sending a communication data packet to a target node device exceeds a preset number threshold in a first data transmission time slot, the source node device sends an RTC data packet to the target node device in a second data transmission time slot, the source node device is used to describe a UAV device in a UAV cluster self-organizing network, the target node device is a UAV device in the UAV cluster self-organizing network that communicates data with the source node device, and the second data transmission time slot is the next data transmission time slot of the first data transmission time slot;

[0007] After receiving the RTC data packet, the target node device sends a CTC data packet to the source node device;

[0008] The cooperative node device obtains the RTC data packet and the CTC data packet by listening to the communication data of the source node device, the cooperative node device is determined by a node control device based on the target MAC address of the RTC data packet from the corresponding cooperative communication node table of the source node device, and the cooperative node device is a UAV device in the UAV cluster self-organizing network that cooperates with the source node device to retransmit data;

[0009] the source node device sends the communication data packet to the target node device in a third data transmission time slot after receiving the CTC data packet;

[0010] the cooperative node device sends the communication data packet to the target node device in a preset transmission time slot;

[0011] the target node device sends a data confirmation signal to the source node device after receiving the communication data packet;

[0012] the source node device receives the data confirmation signal and determines that the cooperative transmission of the communication data packet is successful.

[0013] In a second aspect, a cooperative retransmission system based on dynamic self-organizing TDMA is provided according to the present disclosure, including a source node device, a target node device, and a cooperative node device;

[0014] The source node device is configured to send an RTC data packet to the target node device in a second data transmission time slot if the number of communication failures in sending a communication data packet to the target node device exceeds a preset number threshold in a first data transmission time slot. The source node device is used to describe a UAV device in a UAV cluster self-organizing network. The target node device is a UAV device in the UAV cluster self-organizing network that communicates data with the source node device. The second data transmission time slot is the next data transmission time slot of the first data transmission time slot.

[0015] The target node device is configured to send a CTC data packet to the source node device after receiving the RTC data packet.

[0016] The cooperative node device is configured to obtain the RTC data packet and the CTC data packet by listening to the communication data of the source node device. The cooperative node device is determined by a node control device based on the target MAC address of the RTC data packet from a cooperative communication node table corresponding to the source node device. The cooperative node device is a UAV device in the UAV cluster self-organizing network that cooperatively retransmits data of the source node device.

[0017] The source node device is further configured to send the communication data packet to the target node device in a third data transmission time slot after receiving the CTC data packet.

[0018] The cooperative node device is further configured to send the communication data packet to the target node device in a preset transmission time slot.

[0019] The target node device is further configured to send a data confirmation signal to the source node device after receiving the communication data packet.

[0020] The source node device is further configured to receive the data acknowledgement signal and determine that the cooperative transmission of the communication data packet is successful.

[0021] In a third aspect, a computer device is provided, which includes a memory and a processor. The memory stores a computer program. When the processor executes the computer program, the steps of the cooperative retransmission method based on dynamic self-organizing TDMA are implemented.

[0022] In a fourth aspect, a computer readable storage medium is provided, which stores a computer program. When the computer program is executed by a processor, the steps of the cooperative retransmission method based on dynamic self-organizing TDMA are implemented.

[0023] The cooperative retransmission method based on dynamic self-organizing TDMA provided by the embodiments of the present application is as follows. If the number of communication failures of the source node device in transmitting the communication data packet to the target node device exceeds a preset number threshold in a first data transmission time slot, the source node device transmits an RTC data packet to the target node device in a second data transmission time slot. The source node device is used to describe a UAV device in a UAV cluster self-organizing network. The target node device is a UAV device in the UAV cluster self-organizing network that performs data communication with the source node device. The second data transmission time slot is a next data transmission time slot of the first data transmission time slot. After receiving the RTC data packet, the target node device transmits a CTC data packet to the source node device. The cooperative node device obtains the RTC data packet and the CTC data packet by listening to the communication data of the source node device. The cooperative node device is determined by the node control device based on the target MAC address of the RTC data packet from a cooperative communication node table corresponding to the source node device. The cooperative node device is a UAV device in the UAV cluster self-organizing network that performs data retransmission for the source node device. After receiving the CTC data packet, the source node device transmits the communication data packet to the target node device in a third data transmission time slot. The cooperative node device transmits the communication data packet to the target node device in a preset transmission time slot. After receiving the communication data packet, the target node device transmits a data acknowledgement signal to the source node device. The source node device receives the data acknowledgement signal and determines that the cooperative transmission of the communication data packet is successful. In this way, the RTC / CTC handshake mechanism is introduced to coordinate the cooperative retransmission process of the source node device and the cooperative node device. When the communication link between the source node device and the target node device is interrupted, the data packet cooperative retransmission is performed in a timely manner based on cooperative communication, and the problem of packet loss in transmitting the data packet is solved, and the retransmission success rate after the link interruption is effectively improved.

[0024] The above description is only a summary of the technical solutions of the embodiments of the present application. In order to make the technical means of the embodiments of the present application more clearly understood, and to be implemented according to the content of the description, and in order to make the above and other purposes, characteristics and advantages of the embodiments of the present application more obvious and easy to understand, the specific implementation manner of the present application will be described below. BRIEF DESCRIPTION OF DRAWINGS

[0025] In order to more clearly illustrate the technical solutions of the embodiments of the present disclosure, the drawings of the embodiments will be briefly described below. It should be noted that the drawings described below only relate to some embodiments of the present disclosure, but not limit the present disclosure. Among them:

[0026] Figure 1 is a flow diagram of a cooperative retransmission method based on dynamic self-organizing TDMA provided by the present disclosure.

[0027] Figure 2 is an RTC / CTC message example diagram provided by the present disclosure.

[0028] Figure 3 is a cooperative scheduling four-way handshake diagram provided by the present disclosure.

[0029] Figure 4 is an actual performance comparison diagram provided by the present disclosure.

[0030] Figure 5 is a structure diagram of a cooperative retransmission system based on dynamic self-organizing TDMA provided by the present disclosure.

[0031] Figure 6 is a structure diagram of a computer device provided by the present disclosure.

[0032] It should be noted that the elements in the drawings are schematic and not drawn to scale. DETAILED DESCRIPTION

[0033] In order to make the purposes, technical solutions and advantages of the embodiments of the present disclosure more clear, the technical solutions of the embodiments of the present disclosure will be described clearly and completely below in conjunction with the drawings. Obviously, the described embodiments are part of the embodiments of the present disclosure, rather than all the embodiments. Based on the described embodiments of the present disclosure, all other embodiments obtained by those skilled in the art without creative labor also belong to the scope of protection of the present disclosure.

[0034] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this subject matter belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the specification and relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein. As used herein, the statement that two or more parts or components are "coupled" or "connected" together shall mean that the parts are joined or linked together either directly or through one or more intermediate parts or components.

[0035] Reference herein to "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment can be included in at least one embodiment. The appearances of the phrase "an embodiment" in various places in the specification are not necessarily all referring to the same embodiment, nor are they necessarily mutually exclusive of one another. It is expressly understood that any of the embodiments described herein can be incorporated into any other embodiment.

[0036] The term "and / or" used herein only means an association relationship of associated objects, which means that there can be three relationships, for example, A and / or B, which can represent three cases of existence of A, existence of A and B, and existence of B. In addition, the character " / " herein generally represents that the front and rear associated objects are an "or" relationship. Terms such as "first" and "second" are only used to distinguish one component (or part of a component) from another component (or another part of a component).

[0037] In the description of the present application, unless otherwise specified, the meaning of "a plurality of" is two or more (including two), and similarly, "a plurality of groups" means two or more groups (including two groups).

[0038] In order to solve the problem of link interruption caused by unstable link quality in the UAV cluster self-organizing network, it is of great significance to study the application of cooperative communication in distributed MAC (medium access control). However, there are many challenges in applying cooperative transmission to distributed MAC protocols. On the one hand, it is difficult to solve the transmission synchronization problem of traditional cooperative MAC protocols based on CSMA / CA (Carrier Sense Multiple Access with Collision Avoidance). On the other hand, it is difficult to implement multiple service flows coexisting in the cooperative flooding transmission scheme similar to BRN (Barrage Relay Networks). In the multi-service flow scenario, due to the expansion of the signal transmission range caused by cooperative transmission, how to reduce the signal collision problem caused by cooperative transmission is also a problem that needs to be considered when designing a cooperative MAC protocol.

[0039] Most current cooperative schemes involve two transmission stages: a cooperative information exchange stage and a cooperative transmission stage. In the cooperative information exchange stage, the source node and the destination exchange their own data and control messages. In the cooperative transmission stage, potential cooperative nodes retransmit the data packets they have listened to in a cooperative manner to the destination node. In cooperative diversity communication, diversity is achieved due to the cooperation between relay nodes. Currently, cooperative communication-based communication protocols can be mainly divided into two categories: cooperative MAC protocols and large opportunity arrays.

[0040] The embodiment belongs to a cooperative MAC protocol, which distinguishes the packet loss caused by collision or poor link quality by designing a cooperative retransmission triggering mechanism, and introduces the concept of RTC / CTC (Request to Send / Clear to Send protocol) handshake to coordinate the cooperative retransmission process of the source node and the cooperative node. The purpose is to support multiple service flows and better implement distributed cooperative transmission process to meet the diverse communication needs in the UAV cluster self-organizing network and improve the transmission reliability.

[0041] In order to enable those skilled in the art to better understand the scheme of the present application, the technical solutions in the embodiments of the present application will be described clearly and completely in conjunction with the drawings.

[0042] Figure 1 is a flowchart of a cooperative retransmission method based on dynamic self-organizing TDMA provided by the embodiment of the present disclosure, as Figure 1 shown, the specific process of the cooperative retransmission method based on dynamic self-organizing TDMA includes:

[0043] S110. If the number of communication failures of the source node device in sending a communication data packet to the target node device exceeds a preset threshold value in the first data transmission time slot, the source node device sends an RTC data packet to the target node device in the second data transmission time slot.

[0044] The term "source node device" refers to a drone device in a self-organizing drone swarm network, i.e., the data sender that transmits communication packets. The term "destination node device" refers to a drone device in a self-organizing drone swarm network that communicates with the source node device, i.e., the data receiver that transmits communication packets. The second data transmission time slot is the data transmission time slot following the first data transmission time slot.

[0045] When the source node device transmits a communication data packet, it sets a threshold limit for the number of communication failures in a data transmission time slot, which serves as a trigger condition for the cooperative retransmission mechanism. Specifically, the number of consecutive communication failures N in a data transmission time slot is threshold = 1. When the number of communication failures of the source node device to send communication data packets to the target node device exceeds N threshold , the cooperative retransmission mechanism is triggered, and the RTC data packet is sent to the target node device in the second data transmission time slot; when the number of communication failures of the source node device to send the communication data packet to the target node device does not exceed N threshold , the cooperative retransmission mechanism is not triggered.

[0046] The causes of communication packet loss can be categorized as slot collisions and poor link quality. When a slot collision occurs, most conflicts can be resolved by simply retransmitting in the next transmit slot, eliminating the need for coordination. Therefore, a threshold is used to indicate whether packet loss is due to poor link quality.

[0047] In some embodiments, the method of this embodiment further includes:

[0048] The source node device determines multiple communication node devices that have a collaborative communication relationship with the source node device from the drone cluster self-organizing network based on the node search range; the source node device constructs a corresponding collaborative communication node table based on the multiple communication node devices.

[0049] The communication node device and the source node device are one-hop range adjacent nodes or two-hop range adjacent nodes. Each source node device can select a cooperative relay set of each next-hop node device through a one-hop neighbor set and a two-hop neighbor set, and construct and maintain a cooperative communication node table. The node device in the one-hop neighbor set directly communicates with the source node device, i.e., the link between the node device and the source node device is directly connected without a relay device. The node device in the two-hop neighbor set indirectly communicates with the source node device, i.e., the link between the node device and the source node device is indirectly connected through a relay device.

[0050] For example, the source node device traverses the ip address of each one-hop neighbor node in the one-hop neighbor set, and when the ip address in the one-hop neighbor table entry is equal to the ip address in a two-hop neighbor table entry, records the ip address of the relay node in the two-hop neighbor table entry and two link quality parameter values, thereby constructing a cooperative relay table entry of the one-hop neighbor node and adding the cooperative relay table entry to the cooperative communication node table.

[0051] Thus, a cooperative communication node table is maintained for the source node device, which facilitates cooperative retransmission of the source node device through the cooperative node device in the cooperative communication node table when the communication link between the source node device and the target node device is interrupted.

[0052] S120, the target node device sends a CTC data packet to the source node device after receiving the RTC data packet.

[0053] The target node device sends a corresponding CTC data packet to the source node device immediately after receiving the RTC data packet, which facilitates effective response of data.

[0054] S130, the cooperative node device obtains the RTC data packet and the CTC data packet by listening to the communication data of the source node device.

[0055] The cooperative node device is determined by the node control device based on the target MAC address of the RTC data packet from the cooperative communication node table corresponding to the source node device, and the cooperative node device is a UAV device for cooperative data retransmission of the source node device in the UAV cluster self-organizing network.

[0056] RTC and CTC are short frames, and the RTC / CTC short frame interaction can distinguish between transmission failure caused by conflict or strong interference and transmission failure caused by poor link quality.

[0057] In some embodiments, each UAV device in the UAV cluster self-organizing network corresponds to a cooperative communication node table, and the cooperative communication node table corresponding to the source node device includes a plurality of communication node devices, each of which listens to and caches data packets received thereby for future participation in cooperative transmission.

[0058] The method of the embodiment further includes:

[0059] The node control device acquires the cooperative communication node table corresponding to each communication node device, and the cooperative communication node table corresponding to each communication node device includes a plurality of neighboring node devices; the node control device matches the neighboring node devices included in the cooperative communication node table corresponding to each communication node device based on the target MAC address of the RTC data packet; and the node control device determines the cooperative node device based on the matching result of the neighboring node devices included in the cooperative communication node table corresponding to each communication node device and the target MAC address of the RTC data packet.

[0060] If the node control device cannot determine which communication node device is selected by the source node device as the cooperative node device, it is necessary to analyze the target MAC address in the communication data packet and query whether the target MAC address in the communication data packet exists in the one-hop neighbor set of each communication node device, and if it exists, determine the corresponding communication node device as the cooperative node device.

[0061] In some embodiments, the node control device determines the cooperative node device based on the matching result of the neighboring node devices included in the cooperative communication node table corresponding to each communication node device and the target MAC address of the RTC data packet, including:

[0062] The node control device determines the candidate node device corresponding to the source node device based on the matching result of the neighboring node devices included in the cooperative communication node table corresponding to each communication node device and the target MAC address of the RTC data packet; and if the node control device determines that the number of candidate node devices is multiple, it determines the cooperative node device based on the communication link quality between each candidate node device and the source node device.

[0063] The candidate node device has a cooperative communication relationship with the source node device. The candidate node device has a corresponding target MAC address in the communication data packet in the one-hop neighbor set.

[0064] When the number of candidate node devices is multiple, one of the candidate node devices with the highest communication link quality with the source node device can be determined as the cooperative node device based on the communication link quality between each candidate node device and the source node device, so as to facilitate ensuring the data transmission quality in the retransmission process.

[0065] If the number of candidate node devices with the highest communication link quality with the source node device is at least two, one of the at least two candidate node devices with the shortest communication distance with the source node device is selected as the cooperative node device, so that the increased signal propagation range relative to non-cooperative transmission is minimized, thereby reducing the collision probability and improving the efficiency of cooperative retransmission.

[0066] In addition, the cooperative node device can cache the RTC data packet when the RTC data packet is listened to, and a Time To Live (TTL) counter can be set for each cached RTC data packet, so as to ensure the data validity of the cached RTC data packet.

[0067] S140, the source node device sends a communication data packet to the target node device in a third data transmission time slot after receiving the CTC data packet.

[0068] The third data transmission time slot is the next data transmission time slot of the current data transmission time slot. The source node device sends a communication data packet to the target node device in the next data transmission time slot of the current data transmission time slot after receiving the CTC data packet.

[0069] S150, the cooperative node device sends a communication data packet to the target node device in a preset transmission time slot.

[0070] The preset transmission time slot is a data transmission time slot determined by the cooperative node device and the source node device in advance, and the data transmission time slot can be adaptively adjusted based on the transmission state.

[0071] The preset transmission time slot can be the third data transmission time slot or other data transmission time slots. When the preset transmission time slot is the third data transmission time slot, the cooperative node device and the source node device can simultaneously send a communication data packet to the target node device in the preset transmission time slot; when the preset transmission time slot is other data transmission time slots, the cooperative node device can send a communication data packet to the target node device alone.

[0072] In some embodiments, the cooperative node device sends a communication data packet to the target node device in a preset transmission time slot, comprising:

[0073] The cooperative node device acquires the transmission state in the preset transmission time slot. If the cooperative node device determines that the transmission state in the preset transmission time slot is an idle state, the cooperative node device sends a communication data packet to the target node device in the preset transmission time slot.

[0074] If the cooperation node device determines that the transmission state in the preset transmission time slot is the idle state, it means that no node device occupies the preset transmission time slot, and the cooperation node device can participate in the cooperative transmission in the preset transmission time slot to assist the source node device in data retransmission.

[0075] In some embodiments, after the cooperation node device acquires the transmission state in the preset transmission time slot, the method further includes:

[0076] If the cooperation node device determines that the transmission state in the preset transmission time slot is the occupied state, the cooperation node device acquires the MAC address of the transmission node device that occupies the preset transmission time slot.

[0077] If the cooperation node device determines that the MAC address of the transmission node device is the same as the MAC address of the source node device, it means that the preset transmission time slot is only occupied by the source node device, and at this time, the cooperation node device can send the communication data packet to the target node device in the preset transmission time slot at the same time as the source node device.

[0078] In some embodiments, the method further includes:

[0079] If the cooperation node device determines that the transmission state in the preset transmission time slot is the busy state, the cooperation node device updates the preset transmission time slot, and sends the communication data packet to the target node device in the updated preset transmission time slot.

[0080] If the cooperation node device determines that the transmission state in the preset transmission time slot is the busy state, it means that at least two node devices occupy the preset transmission time slot at this time, and the preset transmission time slot can be adjusted in time, such as being delayed by one data transmission time slot, so as to facilitate the cooperation node device to effectively send the communication data packet to the target node device.

[0081] Alternatively, if the cooperation node device determines that the transmission state in the preset transmission time slot is the busy state, the cooperation node device can also not participate in the cooperative transmission at this time.

[0082] S160, after receiving the communication data packet, the target node device sends a data confirmation signal to the source node device.

[0083] After receiving the communication data packet, the target node device immediately sends a data confirmation signal ACK (Acknowledgement) to the source node device, so as to respond to the received communication data packet in time.

[0084] It should be noted that the communication data packet received by the target node device can be sent by the source node device or the cooperative node device. In this embodiment, the target node device sends the data acknowledgement signal to the source node device after receiving the communication data packet for the first time.

[0085] S170, the source node device receives the data acknowledgement signal and determines that the cooperative transmission of the communication data packet is successful.

[0086] If the source node device successfully receives the data acknowledgement signal, it indicates that the cooperative transmission is successful.

[0087] In addition, if the source node device still does not receive the ACK after the cooperative retransmission with the cooperative node device, it is determined that the communication link between the source node device and the target node device has completely failed, and the cooperative communication cannot provide good gain. At this time, the packet communication can be discarded.

[0088] If the source node device waits for the ACK to time out and the timeout number is equal to the preset timeout threshold, the source node device re-sends the RTC data packet to the target node device in the next data transmission time slot of the current data transmission time slot, and triggers the cooperative retransmission mechanism again. If the source node device waits for the ACK to time out and the timeout number is less than the preset timeout threshold, the source node device continues to send the communication data packet to the target node device when the next data transmission time slot arrives.

[0089] In the embodiment, if the number of communication failures of the source node device in sending the communication data packet to the target node device exceeds a preset number threshold, the source node device sends an RTC data packet to the target node device in a second data transmission time slot, the source node device is used to describe a UAV device in a UAV cluster self-organizing network, the target node device is a UAV device in the UAV cluster self-organizing network that performs data communication with the source node device, and the second data transmission time slot is a next data transmission time slot of the first data transmission time slot; after receiving the RTC data packet, the target node device sends a CTC data packet to the source node device; the cooperation node device obtains the RTC data packet and the CTC data packet by listening to the communication data of the source node device, the cooperation node device is determined by the node control device based on the target MAC address of the RTC data packet from a cooperation communication node table corresponding to the source node device, and the cooperation node device is a UAV device that cooperates with the source node device to perform data retransmission in the UAV cluster self-organizing network; after receiving the CTC data packet, the source node device sends a communication data packet to the target node device in a third data transmission time slot; the cooperation node device sends a communication data packet to the target node device in a preset transmission time slot; after receiving the communication data packet, the target node device sends a data confirmation signal to the source node device; the source node device receives the data confirmation signal and determines that the communication data packet cooperation transmission is successful. In this way, the cooperation retransmission process of the source node device and the cooperation node device is coordinated by introducing the RTC / CTC handshake mechanism, the data packet cooperation retransmission is performed in time based on the cooperation communication when the communication link between the source node device and the target node device is interrupted, the problem of packet loss in transmitting the data packet is solved, and the retransmission success rate after the link interruption is effectively improved.

[0090] In summary, the embodiment triggers cooperation retransmission according to that the number of retransmissions reaches a threshold, and introduces the concept of RTC / CTC handshake to coordinate the source node and the cooperation node to send the same data packet in the specified time slot to realize cooperation diversity; the neighbor information obtained by the HELLO packet is used, and the best cooperation node is selected according to the neighbor information and the link quality information of the neighbor. In addition, a cooperation data packet retrieval mechanism is also provided, based on which the cooperation node device can retrieve the uniquely determined data packet according to the data packet ID (Identity Document, identity number) and the sending node MAC address obtained through RTC / CTC exchange. When the link interruption causes the routing information to be unable to be updated in time, the cooperation retransmission is requested in time through cooperation communication, which can improve the success rate of retransmission after the link interruption. Compared with DSO-TDMA, the CR-TDMA technology shows better throughput and end-to-end delivery rate performance in a high link interruption probability environment.

[0091] Specifically includes three stages: the selection stage of the cooperative relay node, the cooperative data packet buffer stage and the cooperative transmission access stage. In the selection stage of the cooperative relay node, CR-TDMA (Time Division Multiple Access) selects a cooperative relay auxiliary node for each next hop node based on the one-hop neighbor set and the two-hop neighbor set of each node; the cooperative data packet buffer stage: the cooperative relay node listens to the data packet sent by the source node, judges whether to buffer the data packet according to the source node MAC address and the destination node MAC address of the data packet, and discards the ACK after receiving it; the cooperative retransmission handshake stage, the node needing cooperation generates a cooperative request control packet (RTC), and the cooperative node participates in the cooperative transmission process according to the information carried by the RTC and the cooperative confirmation packet (CTC) to complete the cooperative transmission.

[0092] In an embodiment, as shown in Figure 2 , each node (such as the source node device, the target node device or the cooperative node device mentioned above) can select the cooperative relay set of each next hop node through its one-hop neighbor set and two-hop neighbor set, and construct and maintain a cooperative communication node table. Node i traverses the ip address of each one-hop neighbor node j in the one-hop neighbor set When the in the one-hop neighbor table entry is equal to the in a certain two-hop neighbor table entry, the ip address of the relay node r in the two-hop neighbor table entry is recorded , and the link quality parameter sinr between node i and node r ir , thereby constructing a cooperative relay table entry of the one-hop neighbor node, filling in in the N_neighbor_main_addr field, filling in in the CO_partner_main_addr field, and filling in sinr ir in the SINR field. Wherein, for a one-hop neighbor node j, if any equal to the ip address of the one-hop neighbor node j is not found in the two-hop neighbor table, then it means that the one-hop neighbor node j has no cooperative relay node to participate in cooperative retransmission; if the number of cooperative relay nodes in the cooperative relay set of a certain node exceeds 2, then the top 2 cooperative relay nodes with the highest SINR value can be selected as the relay nodes participating in cooperation.

[0093] Node i normally performs packet transmission, and at the same time maintains a number of consecutive communication failures Nthreshold = 1, when it does not exceed the set threshold, does not trigger the cooperative retransmission mechanism. All cooperative relay nodes listen and cache the received data packets for future participation in cooperative transmission, because the cooperative relay nodes do not know whether the sending node will select it as a cooperative node before cooperative retransmission, so it can only analyze the destination MAC address of the data packet, and query the destination MAC address in its own one-hop neighbor table N(x), if it exists, then cache the data packet, and set TTL = 4 for each cached data packet in the cache data queue, representing the remaining number of frames that the cached data packet can be retained.

[0094] When the number of consecutive communication failures reaches the threshold value, the RTC / CTC exchange is triggered, and the sending node sends an RTC packet to the receiving node in the next sending time slot. Table 1 is the field format of the RTC and CTC packets.

[0095] Table 1 RTC / CTC field definition

[0096]

[0097] The receiving node j receives the RTC packet in the time slot and replies with a CTC packet, while the cooperative node r plans its next transmission according to the information carried by the RTC and CTC packets. The sending node i and the cooperative node r send the specified data packet at the same time, and the receiving node j receives the data packet and replies with an ACK. When the sending node i successfully receives the ACK, it indicates that the cooperative transmission is successful, Figure 3 The four-way handshake diagram for complete cooperative scheduling.

[0098] In another embodiment, nodes are uniformly deployed in an area of 5 km * 15 km, with a node size of 48, and the maximum transmission radius of the nodes is 2 km, the distance between nodes is 2 / 3 km, and then different power sizes of noise and interference are set to make the links between nodes at different link interruption probability levels. In different access load scenarios, different traffic flow quantity scenarios, and different node moving speed scenarios, the link interruption probability is set to 10% and 50% to respectively simulate the actual situation of low link interruption probability scenario and high link interruption probability scenario.

[0099] The sending node of the service is node 1, and node 1 randomly changes a destination node every random time, and the destination node is randomly selected within one hop of node 1. The traffic rate varies from 100 kbps to 1200 kbps. Node 1 normally communicates and sends packets, and at the same time maintains a number of consecutive communication failures N threshold= 1, when it does not exceed the set threshold, does not trigger the cooperative retransmission mechanism. All the node 1 cooperative relay node listens and caches its received data packets for future participation in cooperative transmission, and sets TTL = 4 for each cached data packet, when no CTC packet is listened to, every frame time, the timer is reduced by 1, and when it is reduced to 0, the data packet is discarded. When the number of consecutive communication failures of node 1 exceeds the threshold = 1, that is, the timer is 2, the RTC / CTC exchange is triggered. The sending node sends the cooperative request in the next sending time slot, and sends the RTC packet to the receiving node j. When the node receives the RTC data packet, it parses the cooperative node MAC address carried by the RTC packet. If the address is equal to the MAC address of itself, it means that it is selected as a cooperative node by the RTC sender, and then the cooperative time slot number S ID , the data packet index P ID and the MAC address of the RTC sending node (SA field) are recorded. Then wait for the arrival of the CTC data packet. At the same time, a CTC timeout time T ctctimeout is also set. If the CTC data packet is received within the CTC timeout time, the cooperative node will send the specified data packet in the specified time slot according to the recorded S ID , P ID and SA field; if the CTC packet receiving timeout, the cooperative node does not do anything and directly returns to the initial state.

[0100] The receiving node j receives the RTC packet in the time slot and replies the CTC packet, and the cooperative node r plans its next transmission according to the information carried by the listened RTC packet and CTC packet. After the RTC / CTC handshake, if the cooperative node r finds that it meets the conditions for participating in cooperation, it then checks the state of the predetermined cooperative transmission time slot. If the time slot state is idle, it means that no node occupies the time slot, and the cooperative node decides to participate in cooperative transmission in the specified time slot; if the time slot state is occupied, then the MAC address of the node occupying the time slot is checked. If the MAC address of the node occupying the time slot is the same as the MAC address of the cooperative transmission initiator, it means that the current time slot is only occupied by the cooperative initiator node, and then the cooperative node decides to cooperate with it for transmission, otherwise it does not participate in cooperation; if the time slot state is busy, it means that at least two nodes are occupying the time slot, and the cooperative node chooses not to participate in cooperative transmission. The sending node and the cooperative node send the specified data packet at the same time, and the receiving node j receives the data packet and replies ACK. When the sending node i successfully receives the ACK, it means that the cooperative transmission is successful.

[0101] Figure 4The trend of end-to-end packet delivery rate of CR-TDMA and DSO-TDMA with the change of link interruption probability is compared, and it is shown by the experiment simulation that the method can effectively improve the end-to-end packet delivery rate of the network under different interruption probabilities.

[0102] The cooperation relay node selection strategy in the embodiment fully utilizes the information of one-hop and two-hop neighbor nodes, improves the efficiency of relay node selection, and thus improves the success rate of cooperation retransmission; through the short frame packet specially used for transmitting cooperation information, the signaling overhead is reduced to the maximum, and the network performance is improved with smaller retransmission overhead; a special distributed cooperation transmission collision avoidance mechanism is adopted, the node closest to the source node is selected as the cooperation node as much as possible, and the access of the cooperation node is decided by using the information of the time slot state table, so that the collision of cooperation transmission is reduced and the efficiency of cooperation retransmission is improved; the retransmission mechanism is triggered only after the link quality is poor and continuous multiple retransmission fails, and thus has good backward compatibility with DSO-TDMA.

[0103] Figure 5 A structure schematic diagram of a cooperation retransmission system based on dynamic self-organizing TDMA is provided in the embodiment, and the cooperation retransmission system based on dynamic self-organizing TDMA can include a source node device 510, a target node device 520, and a cooperation node device 530.

[0104] The source node device 510 is configured to send an RTC data packet to the target node device in a second data transmission time slot if the number of communication failures of sending a communication data packet to the target node device exceeds a preset number threshold in a first data transmission time slot, and the source node device is used to describe a UAV device in a UAV cluster self-organizing network, the target node device is a UAV device in the UAV cluster self-organizing network which performs data communication with the source node device, and the second data transmission time slot is a next data transmission time slot of the first data transmission time slot.

[0105] The target node device 520 is configured to send a CTC data packet to the source node device after receiving the RTC data packet.

[0106] The cooperation node device 530 is configured to obtain the RTC data packet and the CTC data packet by listening to the communication data of the source node device, and the cooperation node device is determined by a node control device based on the target MAC address of the RTC data packet from a cooperation communication node table corresponding to the source node device, and the cooperation node device is a UAV device in the UAV cluster self-organizing network which performs data retransmission for the source node device.

[0107] The source node device 510 is further configured to send a communication data packet to the target node device in a third data transmission time slot after receiving the CTC data packet.

[0108] The cooperative node device 530 is further configured to send the communication data packet to the target node device within a preset transmission time slot.

[0109] The target node device 520 is further configured to send a data confirmation signal to the source node device after receiving the communication data packet.

[0110] The source node device 510 is further configured to determine that the cooperative transmission of the communication data packet is successful after receiving the data confirmation signal.

[0111] In this embodiment, each unmanned aerial vehicle device in the unmanned aerial vehicle cluster self-organizing network corresponds to a cooperative communication node table, and the cooperative communication node table corresponding to the source node device includes a plurality of communication node devices.

[0112] The node control device is further configured to obtain the cooperative communication node table corresponding to each communication node device, and the cooperative communication node table corresponding to each communication node device includes a plurality of adjacent node devices.

[0113] The node control device is further configured to obtain the cooperative communication node table corresponding to each communication node device, and the cooperative communication node table corresponding to each communication node device includes a plurality of adjacent node devices.

[0114] In this embodiment, the node control device is specifically configured to:

[0115] The node control device is further configured to obtain the cooperative communication node table corresponding to each communication node device, and the cooperative communication node table corresponding to each communication node device includes a plurality of adjacent node devices.

[0116] In this embodiment, the source node device is further configured to determine a plurality of communication node devices having a cooperative communication relationship with the source node device from the unmanned aerial vehicle cluster self-organizing network based on a node search range, and the communication node device and the source node device are one-hop range adjacent nodes or two-hop range adjacent nodes.

[0117] In this embodiment, the cooperative node device is specifically configured to:

[0118] acquire a transmission state in the preset transmission time slot; if it is determined that the transmission state in the preset transmission time slot is an idle state, send a communication data packet to the target node device in the preset transmission time slot.

[0119] In this embodiment, the cooperative node device is specifically configured to:

[0120] If it is determined that the transmission state in the preset transmission time slot is an occupied state, acquire a MAC address of a transmission node device occupying the preset transmission time slot; if it is determined that the MAC address of the transmission node device is the same as the MAC address of the source node device, send a communication data packet to the target node device in the preset transmission time slot.

[0121] In this embodiment, the cooperative node device is specifically configured to:

[0122] If it is determined that the transmission state in the preset transmission time slot is a busy state, update the preset transmission time slot; send a communication data packet to the target node device in the updated preset transmission time slot.

[0123] The cooperative retransmission system based on dynamic self-organizing TDMA provided by the present disclosure can execute the above method embodiments, and the specific implementation principles and technical effects can be referred to the above method embodiments, which will not be described here again.

[0124] The present application also provides a computer device. For details, please refer to Figure 6 , Figure 6 The present application also provides a computer device. For details, please refer to

[0125] The computer device includes a memory 610 and a processor 620 which are connected to each other for communication through a system bus. It should be noted that only the computer device with the memory 610 and the processor 620 is shown in the figure, but it should be understood that it is not required to implement all the shown components, and more or fewer components can be alternatively implemented. Among them, those skilled in the art can understand that the computer device herein is a device capable of automatically performing numerical calculation and / or information processing according to pre-set or stored instructions, and its hardware includes but is not limited to microprocessors, application specific integrated circuits (ASICs), field programmable gate arrays (FPGAs), digital signal processors (DSPs), embedded devices, etc.

[0126] The computer device can be a desktop computer, a notebook computer, a palm computer, a cloud server, or the like. The computer device can interact with the user through a keyboard, a mouse, a remote controller, a touchpad, a voice control device, or the like.

[0127] The memory 610 includes at least one type of readable storage medium, such as a non-volatile memory or a volatile memory, for example, a flash memory, a hard disk, a multimedia card, a card-type memory (e.g., an SD or a DX memory, or the like), a random access memory (RAM), a read-only memory (ROM), an erasable programmable ROM (EPROM), an electrically erasable programmable ROM (EEPROM), a programmable ROM (PROM), a magnetic memory, a magnetic disk, an optical disk, or the like. The RAM can include a static RAM or a dynamic RAM. In some embodiments, the memory 610 can be an internal storage unit of the computer device, such as a hard disk or a memory of the computer device. In other embodiments, the memory 610 can also be an external storage device of the computer device, such as a plug-in hard disk, a smart media card (SMC), a secure digital (SD) card, a flash card, or the like. Of course, the memory 610 can include both an internal storage unit and an external storage device of the computer device. In this embodiment, the memory 610 is generally used to store an operating system and various application software installed in the computer device, such as the program code of the above method, or the like. In addition, the memory 610 can also be used to temporarily store various data that has been output or will be output.

[0128] The processor 620 is generally used to perform the overall operation of the computer device. In this embodiment, the memory 610 is used to store program codes or instructions, and the processor 620 is used to execute the program codes or instructions stored in the memory 610 or process data, such as running the program codes of the above method.

[0129] In this article, the bus can be an Industry Standard Architecture (ISA) bus, a Peripheral Component Interconnect (PCI) bus, or an Extended Industry Standard Architecture (EISA) bus, etc. The bus system can be divided into an address bus, a data bus, a control bus, etc. For ease of representation, only one thick line is shown in the figure, but it does not mean that there is only one bus or only one type of bus.

[0130] Another embodiment of the present application also provides a computer readable medium, which can be a computer readable signal medium or a computer readable medium. The processor in the computer reads the computer readable program code stored in the computer readable medium, so that the processor can perform the function actions specified in each step or combination of steps in the above method; generate the device implementing the function actions specified in each block or combination of blocks in the block diagram.

[0131] The computer readable medium includes but is not limited to electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, device or apparatus, or any appropriate combination of the foregoing, for storing program code or instructions, which include computer operation instructions, and the processor for executing the program code or instructions of the above method stored in the memory.

[0132] The definition of the memory and the processor can refer to the description of the foregoing computer device embodiment, which will not be repeated here.

[0133] In several embodiments provided in the present application, it should be understood that the disclosed system, device and method can be implemented in other ways. For example, the device embodiment described above is only schematic, for example, the division of modules or units is only a logical function division, and actual implementation can have another division manner, for example, a plurality of units or components can be combined or integrated into another system, or some features can be ignored or not executed. In addition, the coupling or direct coupling or communication connection between the displayed or discussed each other can be through some interface, indirect coupling or communication connection between the units or devices, which can be electrical, mechanical or other forms.

[0134] The function units or modules in each embodiment of the present application can be integrated in one processing unit, or each unit can exist physically, or two or more units can be integrated in one unit. The integrated unit can be realized in the form of hardware or in the form of software function unit.

[0135] If the integrated unit is implemented in the form of a software function unit and sold or used as an independent product, it can be stored in a computer readable storage medium. Based on such understanding, the technical solutions of the present application essentially or say the part that contributes to the prior art or the whole or part of the technical solutions can be embodied in the form of a software product. The computer software product is stored in a storage medium and includes a number of instructions for causing a computer device (which can be a personal computer, a server, or a network device, etc.) or a processor to execute all or part of the steps of the methods in the various embodiments of the present application. The aforementioned storage medium includes: a U disk, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk, and various media that can store program codes.

[0136] In the claims, any reference signs placed between parentheses shall not be construed as limiting the claim. The word "comprising" does not exclude the presence of elements or steps not listed in a claim. The word "a" or "an" preceding an element does not exclude the presence of a plurality of such elements. The application can be implemented by means of both hardware and software, and any combination thereof. In the device claim enumerating several means, several of these means can be embodied by one and the same item of hardware. The mere fact that certain measures are recited in mutually different claims does not indicate that a combination of these measures cannot be used to advantage. The use of relative terms such as "first", "second" and "third", etc. does not connote any prioritization, but such terms are used to distinguish a certain feature from another feature with the same name. The steps of the methods described in the above embodiments should not be understood as necessarily limited in their sequence, except when this is explicitly specified.

[0137] The above embodiments are only used to illustrate the technical solutions of the present application, rather than limit them; even though the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that: it can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement for part of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A collaborative retransmission method based on dynamic self-organizing TDMA, characterized in that: include: The source node device sends an RTC data packet to the target node device in a second data transmission time slot if the number of communication failures in sending a communication data packet to the target node device exceeds a preset number threshold within a first data transmission time slot. The source node device is used to describe a drone device in a drone cluster self-organizing network, and the target node device is a drone device in the drone cluster self-organizing network that performs data communication with the source node device. The second data transmission time slot is a data transmission time slot next to the first data transmission time slot. The RTC data packet is used to describe a collaboration request control packet. After receiving the RTC data packet, the target node device sends a CTC data packet to the source node device; the CTC data packet is used to describe the collaboration confirmation packet; The collaborative node device obtains the RTC data packet and the CTC data packet by monitoring the communication data of the source node device. The collaborative node device is determined by the node control device from the collaborative communication node table corresponding to the source node device based on the target MAC address of the RTC data packet. The collaborative node device is a drone device in the drone cluster self-organizing network that collaborates with the source node device to perform data retransmission; After receiving the CTC data packet, the source node device sends the communication data packet to the target node device in a third data transmission time slot; The cooperation node device sends the communication data packet to the target node device within a preset transmission time slot; After receiving the communication data packet, the target node device sends a data confirmation signal to the source node device; The source node device receives the data confirmation signal and determines that the collaborative transmission of the communication data packet is successful.

2. The method according to claim 1, characterized in that Each drone device in the drone cluster self-organizing network corresponds to a collaborative communication node table, and the collaborative communication node table corresponding to the source node device includes: multiple communication node devices; The method further comprises: The node control device obtains a cooperative communication node table corresponding to each of the communication node devices, where the cooperative communication node table corresponding to the communication node device includes: a plurality of adjacent node devices; The node control device matches the adjacent node device included in the cooperative communication node table corresponding to each of the communication node devices based on the target MAC address of the RTC data packet; The node control device determines the cooperative node device based on a matching result between a destination MAC address of the RTC data packet and the adjacent node device included in the cooperative communication node table corresponding to each of the communication node devices.

3. The method according to claim 2, characterized in that The node control device determines the cooperative node device based on a matching result between a destination MAC address of the RTC data packet and the adjacent node device included in the cooperative communication node table corresponding to each of the communication node devices, including: The node control device determines, based on the destination MAC address of the RTC data packet and the matching result of the adjacent node devices included in the cooperative communication node table corresponding to each of the communication node devices, a candidate node device corresponding to the source node device, wherein the candidate node device has a cooperative communication relationship with the source node device; If the node control device determines that there are multiple candidate node devices, the node control device determines the cooperative node device based on the quality of the communication link between each candidate node device and the source node device.

4. The method according to claim 1, wherein Also includes: The source node device determines, based on a node search range, a plurality of communication node devices having a cooperative communication relationship with the source node device from the drone cluster self-organizing network, wherein the communication node devices and the source node device are adjacent nodes within a one-hop range or adjacent nodes within a two-hop range; The source node device constructs a corresponding collaborative communication node table based on the multiple communication node devices.

5. The method according to claim 1, wherein The cooperation node device sends the communication data packet to the target node device within a preset transmission time slot, including: The cooperation node device obtains the transmission status in the preset transmission time slot; If the cooperation node device determines that the transmission state in the preset transmission time slot is an idle state, the cooperation node device sends the communication data packet to the target node device in the preset transmission time slot.

6. The method according to claim 5, characterized in that Also includes: If the cooperation node device determines that the transmission state in the preset transmission time slot is an occupied state, then obtaining the MAC address of the transmission node device occupying the preset transmission time slot; If the cooperation node device determines that the MAC address of the transmission node device is the same as the MAC address of the source node device, the cooperation node device sends the communication data packet to the target node device within the preset transmission time slot.

7. The method according to claim 5, characterized in that Also includes: If the cooperation node device determines that the transmission state in the preset transmission time slot is a busy state, updating the preset transmission time slot; The cooperation node device sends the communication data packet to the target node device within the updated preset transmission time slot.

8. A cooperative retransmission system based on dynamic self-organizing TDMA, characterized in that: include: Source node device, target node device and cooperative node device; The source node device is configured to send an RTC data packet to the target node device in a second data transmission time slot if the number of communication failures in sending a communication data packet to the target node device exceeds a preset number threshold within a first data transmission time slot. The source node device is configured to describe a drone device in a drone cluster self-organizing network, and the target node device is a drone device in the drone cluster self-organizing network that performs data communication with the source node device. The second data transmission time slot is a data transmission time slot subsequent to the first data transmission time slot. The RTC data packet is configured to describe a collaboration request control packet. The target node device is configured to send a CTC data packet to the source node device after receiving the RTC data packet; the CTC data packet is used to describe a collaboration confirmation packet; The collaborative node device is used to obtain the RTC data packet and the CTC data packet by monitoring the communication data of the source node device. The collaborative node device is determined by the node control device from the collaborative communication node table corresponding to the source node device based on the target MAC address of the RTC data packet. The collaborative node device is a drone device in the drone cluster self-organizing network that cooperates with the source node device to retransmit data; The source node device is further configured to send the communication data packet to the target node device within a third data transmission time slot after receiving the CTC data packet; The cooperation node device is further configured to send the communication data packet to the target node device within a preset transmission time slot; The target node device is further configured to send a data confirmation signal to the source node device after receiving the communication data packet; The source node device is further configured to receive the data confirmation signal and determine that the collaborative transmission of the communication data packet is successful.

9. The system according to claim 8, characterized in that Each drone device in the drone cluster self-organizing network corresponds to a collaborative communication node table, and the collaborative communication node table corresponding to the source node device includes: multiple communication node devices; Also included: a node control device; The node control device is used to obtain the collaborative communication node table corresponding to each of the communication node devices, where the collaborative communication node table corresponding to the communication node device includes: multiple adjacent node devices; based on the target MAC address of the RTC data packet, matching the adjacent node devices included in the collaborative communication node table corresponding to each of the communication node devices; based on the target MAC address of the RTC data packet, and the matching result of the adjacent node devices included in the collaborative communication node table corresponding to each of the communication node devices, determining the collaborative node device.

10. The system according to claim 9, characterized in that The node control device is specifically used to: Based on the target MAC address of the RTC data packet and the matching results of the adjacent node devices included in the collaborative communication node table corresponding to each of the communication node devices, the candidate node device corresponding to the source node device is determined, and there is a collaborative communication relationship between the candidate node device and the source node device; if it is determined that there are multiple candidate node devices, the collaborative node device is determined based on the quality of the communication link between each of the candidate node devices and the source node device.

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