Cooperative retransmission method and system based on dynamic self-organizing TDMA (Time Division Multiple Access)

Abstract

The invention provides a cooperative retransmission method and system based on dynamic self-organizing TDMA, and the method comprises the steps: a source node device sends 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 equipment sends the CTC data packet to the source node equipment; the cooperative node device obtains an RTC data packet and a CTC data packet by monitoring communication data of the source node device; the source node equipment sends a communication data packet to the target node equipment in the third data transmission time slot; the cooperative node device sends a communication data packet to the target node device in a preset transmission time slot; the target node equipment sends a data confirmation signal to the source node equipment; and the source node equipment receives the data confirmation signal and determines that the cooperative transmission of the communication data packet succeeds. Therefore, the retransmission success rate after link interruption is effectively improved.

Description

Technical Field

[0001] The embodiments of the present disclosure relate to the field of wireless communication technology, and in particular, to a collaborative retransmission method and system based on dynamic self-organizing TDMA. Background Art

[0002] The drone swarm self-organizing network is a highly flexible and adaptive network with the characteristics of fast node movement, complex and changeable link environment, large network range, and dense node distribution. In this case, the links between nodes are often interrupted.

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

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

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

[0006] 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 in the first data transmission time slot, the source node device is used to describe a drone device in a drone cluster self-organizing network, the target node device is a drone device in the drone cluster self-organizing network that performs data communication 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 cooperation node device obtains the RTC data packet and the CTC data packet by monitoring the communication data of the source node device. The cooperation node device is determined by the node control device from the cooperation communication node table corresponding to the source node device based on the target MAC address of the RTC data packet. The cooperation node device is a drone device in the drone cluster self-organizing network that cooperates with the source node device to perform data retransmission;

[0009] 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;

[0010] The cooperation node device sends the communication data packet to the target node device within a preset transmission time slot;

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

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

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

[0014] The source node device is used 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 drone device in a drone cluster self-organizing network. 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.

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

[0016] The cooperation 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 cooperation node device is determined by the node control device from the cooperation communication node table corresponding to the source node device based on the target MAC address of the RTC data packet. The cooperation node device is a drone device in the drone cluster self-organizing network that cooperates with the source node device to perform data retransmission;

[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 cooperation node device is further used to send the communication data packet to the target node device within 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 also used to receive the data confirmation signal and determine that the collaborative transmission of the communication data packet is successful.

[0021] In a third aspect, a computer device is provided, including a memory and a processor, wherein a computer program is stored in the memory, and when the processor executes the computer program, the steps of the collaborative retransmission method based on dynamic self-organizing TDMA in any of the above embodiments are implemented.

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

[0023] The collaborative retransmission method based on dynamic self-organizing TDMA provided in the embodiment of the present application is that, in the first data transmission time slot, if the number of communication failures of sending a communication data packet to a target node device exceeds a preset number threshold, the source node device sends an RTC data packet to the target node device in the second data transmission time slot. The source node device is used to describe a drone device in a drone cluster self-organizing network. The target node device is a drone device that performs data communication with the source node device in the drone cluster self-organizing network. The second data transmission time slot is the 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 collaborative node device monitors the source node device's Communication data, obtain RTC data packets and CTC data packets, the cooperative node device is determined by the node control device from the cooperative communication node table corresponding to the source node device based on the target MAC address of the RTC data packet, and the cooperative node device is a drone device that cooperates with the source node device in the self-organizing network of the drone cluster to retransmit data; after receiving the CTC data packet, the source node device sends a communication data packet to the target node device in the third data transmission time slot; the cooperative node device sends a communication data packet to the target node device in the 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 cooperative transmission of the communication data packet is successful. In this way, by introducing the RTC / CTC handshake mechanism 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 is promptly retransmitted based on the cooperative communication, which solves the problem of packet loss in the transmission data packet and effectively improves the retransmission success rate after the link is interrupted.

[0024] The above description is only an overview of the technical solution of the embodiment of the present application. In order to more clearly understand the technical means of the embodiment of the present application, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the embodiment of the present application more obvious and easy to understand, the specific implementation methods of the present application are listed below. BRIEF DESCRIPTION OF THE 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 are not intended to limit the present disclosure, wherein:

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

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

[0028] Figure 3 This is a schematic diagram of a collaborative scheduling four-way handshake provided by the present disclosure.

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

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

[0031] Figure 6 It is a structural schematic 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 purpose, technical solution and advantages of the embodiments of the present disclosure clearer, the technical solution of the embodiments of the present disclosure will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the present disclosure, rather than all of the embodiments. Based on the described embodiments of the present disclosure, all other embodiments obtained by those skilled in the art without creative work also fall within 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 a person skilled in the art to which the subject matter of the present disclosure belongs. It will be further understood that terms such as those defined in commonly used dictionaries should be interpreted as having a meaning consistent with their meaning in the context of the specification and the relevant art, and will not be interpreted in an idealized or overly formal form unless otherwise explicitly defined herein. As used herein, a statement that two or more parts are "connected" or "coupled" together shall mean that the parts are joined together directly or through one or more intermediate components.

[0035] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase "embodiments" in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0036] The term "and / or" in this article is only a description of the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B can mean: A exists, A and B exist at the same time, and B exists. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship. Terms such as "first" and "second" are only used to distinguish one component (or a part of a component) from another component (or another part of a component).

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

[0038] In order to solve the link interruption caused by unstable link quality in the self-organizing network of drone clusters, 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, the transmission synchronization problem of traditional cooperative MAC protocols based on CSMA / CA (CarrierSense Multiple Access with Collision Avoidance) is difficult to solve; on the other hand, cooperative flooding transmission schemes such as BRN (Barrage Relay Networks) are difficult to achieve the coexistence of multiple business flows. In addition, in the scenario of multiple business flows, since cooperative transmission will cause the range of signal transmission to expand, how to reduce the signal collision problem caused by cooperative transmission is also something that needs to be considered when designing cooperative MAC protocols.

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

[0040] This embodiment belongs to a collaborative MAC protocol. It designs a collaborative retransmission trigger mechanism to distinguish packet loss caused by collision or poor link quality, and introduces the concept of RTC / CTC (Request to Send / Allow to Send protocol) handshake to coordinate the collaborative retransmission process of the source node and the collaborative node. The purpose is to support multiple business flows and better realize the distributed collaborative transmission process to meet the diverse communication needs in the drone cluster self-organizing network and improve the reliability of transmission.

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

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

[0043] S110: If the number of communication failures 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.

[0044] The source node device is used to describe the drone device in the drone cluster self-organizing network, that is, the data sender that transmits the communication data packet. The target node device is the drone device that performs data communication with the source node device in the drone cluster self-organizing network, that is, the data receiver that transmits the communication data packet. The second data transmission time slot is the next data transmission time slot of 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 as a trigger condition for the collaborative 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 reasons for communication data packet loss can be divided into time slot conflict and poor link quality. When a time slot conflict occurs, most time slot conflict problems can be solved by retransmitting in the next transmission time slot. At this time, there is no need for cooperation. Therefore, a threshold value is selected to indicate whether the data packet loss is caused by poor link quality.

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

[0048] The source node device determines a plurality of communication node devices having a cooperative 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 cooperative communication node table based on the plurality of communication node devices.

[0049] Among them, the communication node device and the source node device are adjacent nodes within one hop range or adjacent nodes within two hop range. Each source node device can select the cooperative relay set of each next-hop node device through its one-hop neighbor set and two-hop neighbor set to build and maintain a cooperative communication node table. The node devices included in the one-hop neighbor set communicate directly with the source node device, that is, the link between the node device and the source node device is directly connected, and there is no relay device in the middle; the node devices included in the two-hop neighbor set communicate indirectly with the source node device, that is, the link between the node device and the source node device is indirectly connected, and is connected through a relay device in the middle.

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

[0051] Therefore, a cooperative communication node table is maintained for the source node device, so that when the communication link between the source node device and the target node device is interrupted, the cooperative node devices in the cooperative communication node table can assist the source node device in cooperative retransmission.

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

[0053] Among them, after receiving the RTC data packet, the target node device will immediately send a corresponding CTC data packet to the source node device to facilitate effective data response.

[0054] S130. The cooperative node device obtains the RTC data packet and the CTC data packet by monitoring the communication data of the source node device.

[0055] Among them, 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 that collaborates with the source node device in the drone cluster self-organizing network to retransmit data.

[0056] RTC and CTC are short frames. Through the interaction of short frames such as RTC / CTC, it is possible to distinguish between transmission failures caused by conflicts or strong interference and transmission failures caused by poor link quality.

[0057] In some embodiments, 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, each communication node device listens to and caches the data packets it receives for future participation in collaborative transmission.

[0058] The method of this embodiment also includes:

[0059] The node control device obtains the collaborative communication node table corresponding to each communication node device, and the collaborative communication node table corresponding to the communication node device includes: multiple adjacent node devices; the node control device matches the adjacent node devices included in the collaborative communication node table corresponding to each communication node device based on the target MAC address of the RTC data packet; the node control device determines the collaborative node device 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 communication node device.

[0060] Among them, the node control device cannot determine which communication node device the source node device selects as the cooperative node. It is necessary to parse 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. If it exists, the corresponding communication node device is determined to be a cooperative node device.

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

[0062] The node control device determines the candidate node device corresponding to the source node device 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 communication node device; if the node control device determines that there are multiple candidate node devices, it determines the collaborative node device based on the quality of the communication link between each candidate node device and the source node device.

[0063] There is a cooperative communication relationship between the candidate node device and the source node device. The one-hop neighbor set of the candidate node device corresponds to the target MAC address in the communication data packet.

[0064] When there are multiple candidate node devices, based on the quality of the communication link between each candidate node device and the source node device, a candidate node device with the highest communication link quality with the source node device can be determined as a collaborative node device, so as to ensure the data transmission quality during the writing and 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, then the candidate node device with the shortest communication distance with the source node device among the at least two candidate node devices is selected as the collaborative node device to ensure that the signal propagation range increased by collaborative transmission relative to non-collaborative transmission is minimized, thereby reducing the collision probability and improving the efficiency of collaborative retransmission.

[0066] In addition, when the cooperative node device monitors and obtains the RTC data packet, it can cache the RTC data packet and set a time to live (TTL) counter for each cached RTC data packet to ensure the data validity of the cached RTC data packet.

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

[0068] The third data transmission time slot is the next data transmission time slot of the current data transmission time slot. After receiving the CTC data packet, 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.

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

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

[0071] The preset transmission time slot may 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 may 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 may send a communication data packet to the target node device alone.

[0072] In some embodiments, the cooperation node device sends a communication data packet to the target node device within a preset transmission time slot, including:

[0073] The cooperative node device obtains 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, it sends a communication data packet to the target node device in the preset transmission time slot.

[0074] When the cooperative node device determines that the transmission state in the preset transmission time slot is idle, it means that no node device occupies the preset transmission time slot. Then the cooperative node device can participate in 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 obtains the transmission status in the preset transmission time slot, the method of this embodiment further includes:

[0076] If the cooperative node device determines that the transmission state within the preset transmission time slot is an occupied state, it obtains the MAC address of the transmission node device occupying the preset transmission time slot; if the cooperative 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 sends a communication data packet to the target node device within the preset transmission time slot.

[0077] Among them, if the cooperative 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. At this time, the cooperative node device can send communication data packets to the target node device in the preset transmission time slot at the same time as the source node device.

[0078] In some embodiments, it also includes:

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

[0080] Among them, if the cooperative node device determines that the transmission status within the preset transmission time slot is a 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 postponing one data transmission time slot, so as to facilitate the cooperative node device to effectively send communication data packets to the target node device.

[0081] Alternatively, if the cooperative node device determines that the transmission state in the preset transmission time slot is a busy state, the cooperative node device may not participate in the cooperative transmission.

[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, confirmation character) 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 may be sent by the source node device or the cooperative node device. In this embodiment, the target node device may send a data confirmation 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 confirmation signal and determines that the collaborative transmission of the communication data packet is successful.

[0086] Among them, when the source node device successfully receives the data confirmation signal, it indicates that the collaborative transmission is successful.

[0087] In addition, if the source node device still does not receive ACK after 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 a good gain. At this time, the packet communication can be discarded.

[0088] If the source node device waits for ACK for a timeout and the number of timeouts is equal to the preset timeout threshold, the RTC data packet is resent to the target node device in the next data transmission time slot of the current data transmission time slot, triggering the collaborative retransmission mechanism again. If the source node device waits for ACK for a timeout and the number of timeouts is less than the preset timeout threshold, the communication data packet is continued to be sent to the target node device when the next data transmission time slot arrives.

[0089] In this embodiment, the source node device sends an RTC data packet to the target node device in the 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 the first data transmission time slot. The source node device is used to describe the drone device in the drone cluster self-organizing network. The target node device is a drone device that performs data communication with the source node device in the drone cluster self-organizing network. The second data transmission time slot is the 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 collaborative node device obtains the RTC data packet by monitoring the communication data of the source node device. According to the RTC data packet and CTC data packet, the cooperative node device is determined by the node control device from the cooperative communication node table corresponding to the source node device based on the target MAC address of the RTC data packet. The cooperative node device is a drone device that cooperates with the source node device in the drone cluster self-organizing network to retransmit data; after receiving the CTC data packet, the source node device sends a communication data packet to the target node device in the third data transmission time slot; the cooperative node device sends a communication data packet to the target node device in the 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 cooperative transmission of the communication data packet is successful. In this way, by introducing the RTC / CTC handshake mechanism 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 is cooperatively retransmitted in time based on the cooperative communication, which solves the problem of packet loss in the transmission data packet and effectively improves the retransmission success rate after the link is interrupted.

[0090] In summary, this embodiment triggers collaborative retransmission according to the number of retransmissions reaching a threshold, and introduces the concept of RTC / CTC handshake to coordinate the source node and the collaborative node to send the same data packet at the same time in the specified time slot to achieve collaborative diversity; the neighbor information obtained by the HELLO packet is used, and the best collaborative node is selected according to the neighbor information and the neighbor's link quality information. In addition, a collaborative data packet retrieval mechanism is also provided, based on which the collaborative node device can retrieve a uniquely determined data packet based on the data packet ID (Identity Document) obtained by the RTC / CTC exchange and the MAC address of the sending node. When the link is interrupted and the routing information cannot be updated in time, the collaborative retransmission is performed in time through the collaborative communication request, which can improve the success rate of retransmission after the link is interrupted. Compared with DSO-TDMA, in an environment with a high link interruption probability, CR-TDMA technology exhibits better throughput and end-to-end delivery rate performance.

[0091] Specifically, it includes three stages: the selection stage of cooperative relay nodes, the cooperative data packet caching stage and the cooperative transmission access stage. In the selection stage of cooperative relay nodes, CR-TDMA (Time Division Multiple Access) selects cooperative relay auxiliary nodes for each next-hop node based on the one-hop neighbor set and the two-hop neighbor set of each node; in the cooperative data packet caching stage: the cooperative relay node monitors the data packet sent by the source node, and determines whether to cache the data packet based on the source node MAC address and the destination node MAC address of the data packet. The cooperative relay node discards it after receiving the ACK; in the cooperative retransmission handshake stage, the node that needs to cooperate generates a cooperative request control packet (Request To Cooperate, RTC), requesting the cooperative node to participate in the cooperative transmission process according to the information carried in the RTC and the cooperative confirmation packet (Comfirm To Cooperate, CTC) to complete the cooperative transmission.

[0092] In one embodiment, Figure 2 As shown in the figure, each node (such as the source node device, target node device or cooperative node device mentioned above) can select the cooperative relay set of each next-hop node through its own one-hop neighbor set and two-hop neighbor set to build 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 a hop neighbor table entry is equal to the value in one of its two-hop neighbor table entries. When recording the IP address of the relay node r in the two-hop neighbor table entry And the link quality parameter sinr between node i and node r ir Value, thereby constructing a cooperative relay table entry of a one-hop neighbor node and adding it to the cooperative relay table. The N_neighbor_main_addr field in this table entry is filled with CO_partner_main_addr field is filled in The SINR field is filled with sinr ir Among them, for a one-hop neighbor node j, if no one is found in the two-hop neighbor table Equal to the IP address of the one-hop neighbor node j This means that the one-hop neighbor node j has no cooperative relay node that can participate in the cooperative retransmission; if the number of cooperative relay nodes in a certain node cooperative relay set exceeds 2, then the cooperative relay nodes with the top 2 SINR values ​​can be finally selected as the relay nodes participating in the cooperation.

[0093] Node i sends packets normally and maintains a number of consecutive communication failures N for each possible neighbor node.threshold =1, when it does not exceed the set threshold value, the cooperative retransmission mechanism is not triggered. All cooperative relay nodes monitor and cache the data packets they receive for future participation in cooperative transmission. Since the cooperative relay node does not know whether the sending node selects it as a cooperative node before cooperative retransmission, it can only parse 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, the data packet is cached. In the cached data queue, TTL=4 is set for each cached data packet, representing the remaining number of frames that can be retained for the cached data packet.

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

[0095] Table 1 RTC / CTC field definition

[0096]

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

[0098] In another embodiment, nodes are uniformly deployed within an area of ​​5km*15km, the node scale is 48, the maximum transmission radius of the node is 2km, and the distance between nodes is 2 / 3km. Then, noise and interference of different power levels are set to make the links between nodes at different link interruption probability levels. In different access load scenarios, different business flow number scenarios, and different node mobility scenarios, the link interruption probability is set to 10% and 50% to simulate the actual conditions of low link interruption probability scenarios and high link interruption probability scenarios, respectively.

[0099] Set the sending node of the service to node 1. Node 1 randomly changes a destination node every random period of time, and the destination node is randomly selected within the one-hop range of node 1. The service rate changes from 100kbps to 1200kbps. Node 1 sends packets normally, and at the same time maintains a number of consecutive communication failures N for each possible neighbor node. threshold=1, when it does not exceed the set threshold value, the collaborative retransmission mechanism is not triggered. All the collaborative relay nodes of node 1 listen to and cache the data packets they receive for future collaborative transmission, and set TTL=4 for each cached data packet. When no CTC message is heard, this timer is decremented by 1 after each frame time, and the data packet is discarded when it is decremented to 0. When the number of consecutive communication failures of node 1 exceeds the threshold value = 1, that is, when the timer is 2, the RTC / CTC exchange is triggered. The sending node makes a collaborative request in the next sending time slot and sends an RTC packet to the receiving node j. When the node receives the RTC data packet, it parses the collaborative node MAC address carried in the RTC packet. If the address is equal to its own MAC address, it means that it has been selected as a collaborative node by the RTC sender, and then the collaborative time slot number S carried by the RTC packet is recorded. ID , data packet index P ID and the MAC address of the RTC sending node (SA field), and then waits for the arrival of the CTC data packet. At the same time, a CTC timeout period T is also set ctctimeout If a CTC packet is received within the CTC timeout period, the cooperative node will ID , P ID and SA fields to send the specified data packet in the specified time slot; if the CTC data packet reception times out, the cooperative node does not do any processing and returns to the initial state directly.

[0100] The receiving node j receives the RTC packet in the time slot and replies with the CTC packet. At the same time, the cooperative node r plans its next transmission according to the information carried in the monitored RTC and CTC packets. After the RTC / CTC handshake, if the cooperative node r finds that it meets the conditions for participating in the cooperation, it will then check the status of the scheduled cooperative transmission time slot. If the time slot status is idle, it means that no node occupies the time slot, and the cooperative node decides to participate in the cooperative transmission in the specified time slot; if the time slot status 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 node initiating the cooperative transmission, it means that the current time slot is only occupied by the cooperative initiating node, and the cooperative node decides to cooperate with it for transmission, otherwise it will not participate in the cooperation; if the time slot status is busy, it means that at least two nodes are occupying the time slot at this time, and the cooperative node chooses not to participate in the cooperative transmission. The sending node and the cooperative node send the specified data packet at the same time. After receiving the data packet, the receiving node j replies ACK. When the sending node i successfully receives ACK, it indicates that the cooperative transmission is successful.

[0101] Figure 4This part compares the trend of the end-to-end data packet delivery rate of CR-TDMA and DSO-TDMA with the link interruption probability. This part illustrates through experimental simulation that the method of this embodiment can effectively improve the end-to-end packet delivery rate of the network under different interruption probabilities.

[0102] In this embodiment, the collaborative relay node selection strategy makes full use of the information of one-hop and two-hop neighbor nodes, improves the efficiency of relay node selection, and thus improves the success rate of collaborative retransmission; by using short frame messages specifically for transmitting collaborative information, the signaling overhead is minimized, and the network performance is improved with a smaller retransmission overhead; a special distributed collaborative transmission conflict avoidance mechanism is adopted, by selecting the node closest to the source node as the collaborative node as much as possible and using the information in the time slot status table to decide the access of the collaborative node, thereby reducing the collision of collaborative transmission and improving the efficiency of collaborative retransmission; the retransmission mechanism is only triggered when the link quality is poor and after multiple consecutive retransmission failures, so it has good backward compatibility with DSO-TDMA.

[0103] Figure 5 A structural diagram of a cooperative retransmission system based on dynamic self-organizing TDMA is provided for this embodiment. The cooperative retransmission system based on dynamic self-organizing TDMA may include: a source node device 510, a target node device 520 and a cooperative node device 530.

[0104] The source node device 510 is used 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 threshold value in a first data transmission time slot. The source node device is used to describe a drone device in a drone cluster self-organizing network. The target node device is a drone device in the drone 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.

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

[0106] The collaborative node device 530 is used to obtain RTC data packets and CTC data packets 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 that collaborates with the source node device in the drone cluster self-organizing network to retransmit data.

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

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

[0110] The source node device 510 is also used to receive a data confirmation signal to determine that the collaborative transmission of the communication data packet is successful.

[0111] In this embodiment, optionally, 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.

[0112] Also includes: node control equipment.

[0113] A node control device is used to obtain a collaborative communication node table corresponding to each communication node device, wherein the collaborative communication node table corresponding to the communication node device includes: a plurality of 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 communication node device; determining the collaborative node device based on the target MAC address of the RTC data packet and the matching result with the adjacent node devices included in the collaborative communication node table corresponding to each communication node device.

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

[0115] 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 communication node device, the candidate node device corresponding to the source node device is determined, and a collaborative communication relationship exists 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 candidate node device and the source node device.

[0116] In this embodiment, optionally, the source node device is also used to determine, based on the node search range, multiple communication node devices that have a collaborative communication relationship with the source node device from the drone cluster self-organizing network, and the communication node device and the source node device are adjacent nodes within one hop range or adjacent nodes within two hop range; based on the multiple communication node devices, a corresponding collaborative communication node table is constructed.

[0117] In this embodiment, the cooperation node device is optionally used to:

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

[0119] In this embodiment, the cooperation node device is optionally used to:

[0120] If it is determined that the transmission state within the preset transmission time slot is an occupied state, the MAC address of the transmission node device occupying the preset transmission time slot is obtained; 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, a communication data packet is sent to the target node device within the preset transmission time slot.

[0121] In this embodiment, the cooperation node device is optionally used to:

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

[0123] The collaborative retransmission system based on dynamic self-organizing TDMA provided by the present disclosure can execute the above method embodiments. Its specific implementation principles and technical effects can be found in the above method embodiments, and the present disclosure will not repeat them here.

[0124] The present application also provides a computer device. Figure 6 , Figure 6 This is a basic structural block diagram of the computer device in this embodiment.

[0125] The computer device includes a memory 610 and a processor 620 that are connected to each other through a system bus. It should be noted that the figure only shows a computer device with a memory 610 and a processor 620, but it should be understood that it is not required to implement all the components shown, and more or fewer components can be implemented instead. Among them, those skilled in the art can understand that the computer device here is a device that can automatically perform numerical calculations 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 (Application Specific Integrated Circuit, ASIC), programmable gate arrays (Field-Programmable Gate Array, FPGA), digital processors (Digital Signal Processor, DSP), embedded devices, etc.

[0126] Computer devices can be computing devices such as desktop computers, notebooks, PDAs, and cloud servers. Computer devices can interact with users through keyboards, mice, remote controls, touch pads, or voice control devices.

[0127] The memory 610 includes at least one type of readable storage medium, and the readable storage medium includes a non-volatile memory or a volatile memory, for example, a flash memory, a hard disk, a multimedia card, a card-type memory (for example, an SD or DX memory, etc.), a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM), an electrically erasable programmable read-only memory (EEPROM), a programmable read-only memory (PROM), a magnetic memory, a magnetic disk, an optical disk, etc., and the RAM may include a static RAM or a dynamic RAM. In some embodiments, the memory 610 may be an internal storage unit of a computer device, for example, a hard disk or a memory of the computer device. In other embodiments, the memory 610 may 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, or a flash card (FlashCard) equipped on the computer device. Of course, the memory 610 may also include both the internal storage unit of the computer device and its external storage device. In this embodiment, the memory 610 is generally used to store the operating system and various application software installed on the computer device, such as the program code of the above method. In addition, the memory 610 may also be used to temporarily store various data that have been output or are to 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, the program code includes computer operation 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 code 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 used in the figure, but it does not mean that there is only one bus or one type of bus.

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

[0131] Computer-readable media include but are not limited to electronic, magnetic, optical, electromagnetic, infrared memory or semiconductor systems, devices or apparatuses, or any appropriate combination of the foregoing, the memory is used to store program codes or instructions, the program codes include computer operating instructions, and the processor is used to execute the program codes or instructions of the above methods stored in the memory.

[0132] For the definitions of memory and processor, please refer to the description of the aforementioned computer device embodiment and will not be repeated here.

[0133] In the several embodiments provided in the present application, it should be understood that the disclosed systems, devices and methods can be implemented in other ways. For example, the device embodiments described above are only schematic, for example, the division of modules or units is only a logical function division, and there may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0134] Each functional unit or module in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit. The above-mentioned integrated unit may be implemented in the form of hardware or in the form of software functional units.

[0135] If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application is essentially or the part that contributes to the prior art or all or part of the technical solution can be embodied in the form of a software product, and the computer software product is stored in a storage medium, including a number of instructions to enable a computer device (which can be a personal computer, server, or network device, etc.) or a processor (processor) to perform all or part of the steps of each embodiment method of the present application. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (Read-Only Memory, ROM), random access memory (Random Access Memory, RAM), disk or optical disk and other media that can store program code.

[0136] In the claims, any reference symbols placed between brackets shall not be construed as limiting the claims. The word "comprising" described in the present application does not exclude the presence of elements or steps not listed in the claims. The word "a" or "an" preceding an element does not exclude the presence of a plurality of such elements. The present application can be implemented with the aid of hardware comprising several different elements and with the aid of a suitably programmed computer. In a unit claim that lists a number of devices, several units of these devices may be embodied by the same hardware item. The use of first, second, and third, etc. does not indicate any order, and these words may be interpreted as names. The steps in the above embodiments, unless otherwise specified, should not be understood as limitations on the order of execution.

[0137] The above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions 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 in the first data transmission time slot, the source node device is used to describe a drone device in a drone cluster self-organizing network, the target node device is a drone device in the drone cluster self-organizing network that performs data communication 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; 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 monitoring the communication data of the source node device. The cooperation node device is determined by the node control device from the cooperation communication node table corresponding to the source node device based on the target MAC address of the RTC data packet. The cooperation node device is a drone device in the drone cluster self-organizing network that cooperates 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 acquires a cooperative communication node table corresponding to each of the communication node devices, wherein 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 the target MAC address of the RTC data packet and the matching result of 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 the target MAC address of the RTC data packet and the matching result of 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 a candidate node device corresponding to the source node device based on the target MAC address of the RTC data packet and the matching result of the adjacent node device included in the cooperative communication node table corresponding to each of the communication node devices, and 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 cooperative node device is determined 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, characterized in that: Also includes: The source node device determines, based on the 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 device 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, characterized in that: 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, it 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 obtain 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, it 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, then updating the preset transmission time slot; The cooperation node device sends the communication data packet to the target node device in 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 used 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 drone device in a drone cluster self-organizing network. 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 target node device is used to send a CTC data packet to the source node device after receiving the RTC data packet; The cooperation 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 cooperation node device is determined by the node control device from the cooperation communication node table corresponding to the source node device based on the target MAC address of the RTC data packet. The cooperation node device is a drone device in the drone cluster self-organizing network that cooperates with the source node device to perform data retransmission; 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; The cooperation node device is further used 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 also used 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 a collaborative communication node table corresponding to each of the communication node devices, wherein the collaborative communication node table corresponding to the communication node device includes: a plurality of 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; determining the collaborative node device based on the target MAC address of the RTC data packet and the matching result with the adjacent node devices included in the collaborative communication node table corresponding to each of the communication node devices.

10. The system according to claim 9, characterized in that The node control device is specifically used for: 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, a candidate node device corresponding to the source node device is determined, and a collaborative communication relationship exists 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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