274 results about "Time division multiple access" patented technology

The invention relates to the technical field of unmanned aerial vehicles, in particular to a mooring unmanned aerial vehicle safety management system which comprises a multi-source data acquisition module, a data fusion and analysis module, an intelligent risk assessment module, a control instruction generation module and an execution mechanism module. The multi-source data acquisition module acquires flight and mooring cable data of the unmanned aerial vehicle by using various sensors, and transmits the flight and mooring cable data to the data fusion and analysis module through a time division multiple access protocol with low packet loss rate and low delay; the intelligent risk assessment module judges a risk level by combining a risk assessment model based on a support vector machine and a Bayesian network algorithm according to the information, and generates prompt information if the risk level exceeds a preset range; the control instruction generation module generates instructions according to a risk prompt and a preset strategy, ranks the instructions and sends the instructions to the execution mechanism module; a flight control system in the execution mechanism module cooperates with a mooring cable electric take-up and pay-off device and the like, real-time adjustment and control over the flight attitude of the unmanned aerial vehicle and the cable state are achieved, and it is ensured that tasks are safely and stably executed in the complex environment.

The invention provides a civil air defense engineering concealed conduit leakage positioning method based on acoustic characteristics, and belongs to the technical field of civil air defense engineering. An acoustic signal acquisition network is constructed by deploying a high-sensitivity hydrophone array, and signals are preprocessed by using a time division multiple access technology and a pulse compression technology; and carrying out time-frequency analysis by applying wavelet transform to extract acoustic features. A time reversal mirror technology is introduced to identify direct propagation and multipath reflection signals, a fluid acoustic coupling propagation equation is constructed to analyze a leakage sound source mechanism, and pipe network topological information and a sound wave speed correction function are combined to compensate a measurement error. Wherein the deep learning pipe network acoustic propagation multi-modal model is fused with a pipeline structure encoder, an acoustic feature extractor and a position prediction decoder, and high-precision leakage positioning and degree evaluation in a complex environment are realized through a three-stage pre-training strategy; the technical problem that it is difficult to accurately locate the position of a leakage point in the complex pipe network environment of civil air defense engineering is solved.

Dynamic Transmission Opportunity (TXOP) sharing between overlapping Basic Service Sets (BSSs) in wireless networks. A sharing Access Point (AP) initiates a process by generating and wirelessly transmitting a control frame to allocate its TXOP to a shared AP in an overlapping BSS. Subsequently, the sharing AP receives a return TXOP frame from the shared AP, indicating the return of any unused TXOP portion. The sharing AP then has the flexibility to either resume its own transmissions using the returned TXOP or reallocate it to an alternative AP. Using the techniques in dense wireless networking environments enables efficient spectrum utilization through dynamic TXOP allocation and reclamation. The techniques address challenges of resource management in multi-AP scenarios, improving overall network performance and reducing interference in overlapping coverage areas.

This disclosure provides methods, components, devices and systems for coordinated time division multiple access (C-TDMA) in Wi-Fi networks for partial bandwidth transmission opportunity (TXOP) sharing. Some aspects more specifically relate to coordinating TXOP sharing in time and frequency. In some examples, a first access point (AP) obtains a TXOP associated with a bandwidth, allocates a duration of the TXOP to a second AP, and selectively communicates with one or more stations (STAs) associated with the first AP via a first portion of the bandwidth within the duration of the TXOP. In other words, the first AP may selectively communicate with one or more STAs associated with the first AP within the duration of the TXOP that the first AP shared with the second AP. Various disclosed protocols and mechanisms further relate to using resources that would otherwise be unutilized within a framework of coordinated medium access.

The invention discloses a time slot synchronization method of a TDMA (Time Division Multiple Access) wireless communication network. The time slot synchronization method comprises the following steps: S1, nodes maintain time slot synchronization among the nodes by using the following synchronization modes: UTC (Universal Time Coordinated) direct synchronization, UTC indirect synchronization, base station direct synchronization, base station indirect synchronization and mobile node semaphore synchronization; s2, the base station plays related information required by time slot synchronization by using a time slot synchronization broadcast message; s3, any node uses a node information broadcast message to play related information required by time slot synchronization, and the related information comprises node attributes, timing unreliability values and synchronization state information required by a synchronization reference selection process; s4, the base station provides time service, so that the mobile node can determine the deviation between the local time and the base station time; and S5, providing precise time synchronization service by the base station, and maintaining time slot synchronization within an error range given by the system. According to the invention, wireless relay networking communication of mass Internet of Things nodes is realized, and the performance index of clock synchronization between the nodes is improved.

The invention relates to the technical field of wireless communication, and discloses a wireless communication control method and system. The method comprises the following steps: generating a periodic configuration structure of a time slot sequence and a node list through communication period calculation and time slot type division on the basis of network topology parameters such as node quantity, distribution position, link quality, transmission delay and the like; heartbeat signal packaging is carried out by using the structure, broadcast power is calculated in combination with a time reference value, and multi-node synchronization is executed by adopting time division multiple access and frequency hopping technologies; triggering downlink data encapsulation and time slot scheduling based on the synchronization mark, generating a transmission record, and driving uplink time slot monitoring and integrity verification; uplink flow characteristics are analyzed, and anti-interference coding and power adaptive adjustment are executed after update configuration is generated, so that closed-loop verification is formed. According to the invention, the multi-node synchronization precision and the anti-interference capability are improved; optimizing the time slot resource utilization rate; and the data transmission integrity and real-time performance are ensured.

This disclosure provides methods, components, devices and systems for schedule announcement enhancements for coordinated time division multiple access (C-TDMA). Some aspects more specifically relate to a sharing AP indicating a schedule announcement for C-TDMA via a frame, such as a poll frame. The frame may include a query to determine interest of one or more shared APs to use a portion of a transmit opportunity (TXOP) obtained by the sharing AP or an indication allocating the portion of the TXOP to the shared APs. The sharing AP may receive a response to the frame via an associated poll response that may indicate an identifier of a shared AP. Various aspects relate more specifically to reallocating one or more fields in a poll frame to indicate information related to the shared TXOP.

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

The invention relates to the technical field of communication, and provides an unmanned aerial vehicle swarm networked measurement and control communication system and method, and the architecture of the communication system comprises a network layer, a link layer and a physical layer. A routing protocol in the network layer uses a cross-layer pulse routing protocol, and all nodes multiplex a neighbor connection relationship in two hops of the link layer in a cross-layer manner; the link layer adopts a pre-allocation and dynamic negotiation resource management strategy based on a time division multiple access protocol and a storage scheduling strategy based on a service quality level; and the physical layer adopts an MIMO technology and an adaptive modulation and coding technology, and supports different service transmission requirements of multiple users. According to the invention, the problems of low channel utilization rate and slow response to dynamic topology change can be solved, and high-capacity information transmission, inter-aircraft cooperative information distribution and unmanned aerial vehicle networked measurement and control services are supported at the same time.

The invention provides a method for sharing a mode, and in one aspect of the invention, various schemes related to a coordinated time division multiple access (C-TDMA) protocol, a transmission opportunity (TXOP) sharing mode for time allocation and parameter exchange in a multi-access point (Multi-AP) system are provided.

The invention provides a photovoltaic cleaning robot multi-machine task scheduling and collaborative operation method and system, electronic equipment and a storage medium, and relates to the technical field of multi-machine task scheduling and collaborative operation, and the method comprises the steps: obtaining the position and speed information of each robot in a robot cluster, and constructing a dynamic adjacency graph model; controlling each robot to interact information through an ad hoc network communication relay node by using a time division multiple access protocol, controlling communication delay and broadcasting obstacle information in real time; dividing a to-be-cleaned area based on related information, determining task sub-areas, and realizing adaptive distribution of tasks according to models; and finally, in the cleaning process, by fusing the swarming control of the artificial potential field method, the adjacent robots synchronously clean the boundary and adjust the track, multi-machine efficient collaborative operation of the photovoltaic cleaning robot can be achieved, and the cleaning efficiency and flexibility are improved.

The invention discloses an industrial remote controller system based on a LoRa technology and a real-time reliable communication control method thereof, and belongs to the technical field of industrial wireless control, and the method specifically comprises the steps: collecting communication link quality parameters, constructing a multi-dimensional link quality evaluation model, and outputting a link quality score; a LoRa physical layer parameter is dynamically adjusted by using a fuzzy logic decision algorithm based on the score, an optimized parameter configuration table is obtained, a bidirectional handshake protocol is established, and an encrypted instruction-response data packet is generated; the central coordinator allocates time division multiple access time slots according to the link quality score, and the industrial remote controller sends encrypted data in the corresponding time slots by using hybrid error correction codes; the controlled equipment receives the data execution instruction, generates a feedback data packet containing an execution state, and returns the feedback data packet to the industrial remote controller through a time division multiple access time slot; the method improves the real-time performance and reliability of the communication of the industrial remote controller.

The invention discloses a wireless monitoring system which comprises a multi-parameter wireless sensing terminal, an anti-interference wireless transmission link, an intelligent host receiving system and an emergency backup module. The multi-parameter wireless sensing terminal collects and sends various types of equipment and environment parameters, the anti-interference wireless transmission link guarantees transmission through time division multiple access and the like, the intelligent host receiving system receives and analyzes data, predicts the parameter trend and links an external system, and the emergency backup module caches or takes over the data when a host is abnormal. According to the invention, the limitation of single parameter monitoring is broken through, and multi-dimensional equipment health monitoring is realized; the data transmission stability and integrity are ensured; equipment faults are early warned in advance, and an external system is linked for rapid handling; the endurance of the multi-parameter wireless sensing terminal is prolonged, the long-term operation requirement is met, and the problem of multiple pain points in the prior art is solved.

This disclosure provides methods, components, devices and systems for error condition management in time division multiple access. Some aspects more specifically relate to recovery procedures for error conditions associated with shared transmission opportunities (TXOPs) for a channel. A sharing access point (AP) may perform a recovery procedure to request control of the channel based on the absence of an expected response message from a shared AP. The expected response message may be in response to a message announcing that the sharing AP will share one or more portions of a TXOP controlled by the sharing AP or a message that allocates a portion of the TXOP to a specific shared AP. A shared AP may perform a contention process to access the channel based on the absence of an expected TXOP allocation frame after reception of scheduling announcement from a sharing AP for a TXOP.

This disclosure provides methods, components, devices and systems for schedule announcement enhancements for coordinated time division multiple access (C-TDMA). Some aspects more specifically relate to a sharing AP indicating a schedule announcement for C-TDMA via a frame, such as a poll frame. The frame may include a query to determine interest of one or more shared APs to use a portion of a transmit opportunity (TXOP) obtained by the sharing AP or an indication allocating the portion of the TXOP to the shared APs. The sharing AP may receive a response to the frame via an associated poll response that may indicate an identifier of a shared AP. Various aspects relate more specifically to reallocating one or more fields in a poll frame to indicate information related to the shared TXOP.

The embodiment of the invention provides a wireless communication method of a TDMA (Time Division Multiple Access) system and a related device, and the wireless communication method is applied to first communication equipment and comprises the following steps: determining a superframe corresponding to a primary service call; the superframe comprises a plurality of service bursts and flexible bursts, the service bursts are used for bearing first service data to be transmitted by the first communication equipment, and the flexible bursts are provided for the first communication equipment to transmit second service data or receive third service data; the first business data, the second business data and the third business data are data of the same business or data of different businesses. The super-frame comprises the flexible burst, and the flexible burst can be provided for the first communication device to send the service data as the idle period, can also be provided for the first communication device to receive the service data transmitted by other devices, and can also be provided for other communication devices to transmit the service data, so that the effect that one super-frame opens up the idle period to transmit other information is realized; service expansion is facilitated, and user requirements can be better supported.

This disclosure provides methods, components, devices and systems for signaling details for coordinated time division multiple access (C-TDMA). Some aspects more specifically relate to signaling details for coordinated time division multiple access. In some examples, an access point (AP) may perform a channel access procedure to obtain access to a wireless medium for communications during a transmission opportunity (TXOP). In some examples, the AP (such as a sharing AP) may share the TXOP with another AP (such as a shared AP) during at least a portion of the TXOP. The sharing AP may transmit one or more messages indicating communication parameters for a second AP to share the portion of the TXOP.

The invention discloses a satellite demodulation equipment frame synchronization method, which comprises a frame synchronization step used for acquiring and guiding demodulation equipment to receive a TDMA (Time Division Multiple Access) burst and detecting TDMA burst time T'of the TDMA burst. According to the synchronization method, the frame plan and the initial TDMA burst decoding data are acquired, the satellite demodulation equipment can receive the DVB signal and the TDMA signal, and frame synchronization can be realized without interaction with the main small station; the synchronization method is also configured with a synchronization result verification step and a synchronization time following step, so that the receiving correctness probability is improved, and the false alarm and missed detection probability is reduced.

The invention discloses a secure communication method combining unmanned aerial vehicle deployment, power distribution and coalition game, and belongs to the technical field of communication. The implementation method comprises the following steps: setting the number of subcarrier channels of the unmanned aerial vehicle as the number of alliances which can be formed, forming non-overlapping alliances by ground nodes, averagely distributing communication time slots to the nodes of the same alliance, and communicating with the unmanned aerial vehicle in a TDMA (Time Division Multiple Access) mode. A communication node in the multi-node alliance selects a node other than the communication node in the alliance as a cooperative interference person and sends the cooperative interference person to a ground eavesdropper, so that the alliance confidentiality and rate during communication are improved. And under the constraint of the cruising ability of the unmanned aerial vehicle, a double-layer optimization problem for improving the overall confidentiality and rate is constructed. In an upper layer optimization problem, a stable alliance formation is obtained based on a TCFG algorithm, and a non-convex optimization problem of a bottom layer is solved under the stable alliance formation, so that an unmanned aerial vehicle deployment result and a ground node power distribution result which enable the overall confidentiality and rate to be maximized are obtained, and the overall confidentiality and rate to be maximized are realized.

The invention belongs to the technical field of wireless communication, and discloses an Internet of Vehicles optimization method and system based on edge computing and time division multiple access, and the method comprises the steps: carrying out the joint optimization of service deployment and replacement, RSU deployment, access control, and task unloading rates in VTUs and RSUs, and achieving the optimization of the Internet of Vehicles. And efficient, low-delay and stable task processing service is provided for vehicle-mounted communication in urban traffic, expressways or disaster areas. According to the method, a double-time-scale optimization strategy is adopted, the decision of service deployment and replacement is carried out on a coarse-grained time scale (frame), and other optimization problems are processed in a fine-grained time scale (time slot). The invention provides an innovative hierarchical DRL algorithm, and in the algorithm, a high-level agent adopts a deep Q network (DQN) proxy and is responsible for optimizing a service deployment and replacement strategy in a frame; and the bottom layer intelligent agent adopts a depth deterministic policy gradient (DDPG) for proxy, and specially solves related optimization problems of task unloading rate, access control and the like in the time slot.

The application discloses a time slot scheduling method of an underwater dynamic multi-hop distribution network based on a time division multiple access protocol, relates to the field of underwater acoustic communication, and is aimed at the underwater multi-hop distribution network, improves the traditional static time slot allocation based on the TDMA protocol, designs a data packet frame structure, comprehensively considers transmission time delays among underwater nodes, dynamically adjusts time slots allocated to the underwater nodes based on the maximum transmission time delay, considers a dynamic node random access condition, and realizes the design of the time slot scheduling method of the underwater dynamic multi-hop distribution network.Compared with the traditional static time slot allocation method, the method can effectively improve the overall throughput of the network and optimize the network operation efficiency.

A main and auxiliary engine communication control method for multiple ship propellers relates to the technical field of ship power control, and comprises a main control propeller and a plurality of auxiliary control propellers, the main control propeller is installed at the leftmost position of a ship body tail plate, and the auxiliary control propellers are installed at other positions of the ship body tail plate in parallel. MAC addresses with the same mark code segment are pre-burnt in the main control propeller and the auxiliary control propeller; the master control propeller establishes a bidirectional data link with the remote controller through a wireless communication protocol; a single-hop star topology network is established between the main control propeller and the auxiliary control propellers, and the main control propeller sends a composite instruction packet to each auxiliary control propeller through a single broadcast channel; and each auxiliary control thruster returns state data to the main control thruster through an independent time division multiple access uplink channel. According to the invention, the defects in the prior art are overcome, the rapid identification and accurate positioning of the equipment are realized, the management and maintenance of the system are simplified, and the flexibility and expandability of the system are greatly improved.

A method and device for a framework for time division multiple access (TDMA) based multi-access point (MAP) coordination. A method of wireless communication performed by a first access point (AP) comprises transmitting, to a second AP, a message including coordination information for coordinating with the first AP on a basis of MAP. The method includes negotiating, with the second AP, a MAP coordination mechanism to be used for the MAP coordination; and forming a MAP coordination group based on the negotiated MAP coordination mechanism.

Wireless-conferencing radios communicate directly with each other without a base station using a multiple access protocol, such as Time Division Multiple Access (TDMA).

The invention discloses a relative navigation method and system suitable for measurement asynchronization and communication delay processing, and relates to the field of navigation. The method solves the problems of measurement asynchronization, communication delay and the like of an existing measurement sharing relative navigation method in practical application. The method comprises the following steps: establishing a total error state equation of a relative navigation system for nodes in a cluster; establishing a multi-source measurement equation of a relative navigation system for the nodes in the cluster; based on a time division multiple access in-turn broadcast type communication mechanism, information data packets are shared by each node in the cluster; constructing a time updating equation and a measurement updating equation, and performing filter time updating and measurement updating; carrying out inertial navigation position extrapolation aiming at measurement asynchronization and communication delay to realize accurate alignment of measurement information containing lagging and an inertial navigation position in time; correcting the error feedback and outputting a relative navigation result. The method is also suitable for the application fields of relative navigation algorithms for measuring asynchronization and communication delay processing and the like.

The application provides a kind of unmanned area overhead transmission line network coverage method, along the line deployment multiple as intelligent spacer intelligent network node, node uses modular hot plug structure, equipped with super capacitor and solid-state battery hybrid energy storage system;Through LoRa communication to build distributed wireless mesh ad hoc network, combined with TDMA time division multiple access and AODV adaptive routing protocol;Utilize the power supply of at least two different principle of multi-source fusion self-powered module power supply;Node collects line monitoring data and carries out edge computing processing, and the processed data is transmitted through multi-hop relay transmission of ad hoc network, and then transmitted to the center master station through the main and standby dual-link redundant transmission architecture.The application can realize long-term stable self-power supply and reliable communication of unmanned transmission line, improve the real-time performance of monitoring data transmission and network invulnerability.

The invention relates to the technical field of wireless communication, and discloses a network-free video transmission scheme implementation method, which comprises the following steps of: firstly, calculating a fitness score according to comprehensive performance parameters such as residual electric quantity and computing resources of nodes through a distributed election algorithm, and electing a unique main control device; then, the main control equipment collects neighbor list information of nodes of the whole network, constructs a weighted global network topological graph, and calculates an optimal relay path with the lowest link cost for a video transmission task based on the topological graph; and finally, the main control equipment generates and broadcasts a global unified time division multiple access time slot allocation table, and accurately allocates conflict-free sending and relay time slots for each node on the optimal path. According to the method, the flexibility of distributed election and the certainty of centralized scheduling are combined, network data collision is effectively avoided, and the reliability and the real-time performance of video transmission in a dynamic and network-free environment are remarkably improved.

The application relates to a time division multiple access time slot allocation method based on a manta ray algorithm and belongs to the technical field of communication networking. The application divides a time frame into an information collection period and a time slot allocation period, and further divides the time slot allocation period into a dedicated time slot period and a dynamic time slot period. In the information collection period, a central node collects time slot application requests of other nodes, judges whether the nodes can continue to apply according to relevant criteria, and gives the nodes priorities according to the traffic volume and the service importance of the nodes. In the dedicated time slot allocation period, high-priority nodes are allocated by using a binary tree block internal equal division method. In the dynamic time slot allocation period, the manta ray algorithm is used to allocate time slots to other nodes. The application is relatively simple to implement, guarantees absolute transmission of the nodes, considers the priorities of the nodes, meets burstiness and long message transmission of the nodes, improves the convergence speed of the algorithm, and improves the overall performance of the network.

The present disclosure provides methods, apparatuses, and systems for sharing resources of a wireless medium. Certain implementations more specifically relate to coordinated AP (CAP) time division multiple access (TDMA) and orthogonal frequency division multiple access (OFDMA) techniques for sharing time or frequency resources of a transmission opportunity (TXOP). According to such techniques, an AP that wins contention for the duration of a TXOP and obtains access to the wireless medium can share its time or frequency resources with other selected APs. To share its resources, the winning AP can divide the TXOP into multiple time or frequency segments, each time or frequency segment including corresponding time or frequency resources representing a portion of the TXOP, and allocate each of these time or frequency segments to the winning AP itself or to one of the selected APs.