1297 results about "Satellite network" patented technology

The invention relates to the technical field of satellite communication, in particular to a high-orbit and low-orbit satellite communication resource scheduling method and system, which collects real-time state information of high-orbit and low-orbit satellites, performs digital simulation of a satellite network based on the real-time information, constructs a satellite network management model and predicts satellite trajectory change. The method comprises the following steps: performing multi-dimensional evaluation on a satellite network management model by using a pre-constructed network evaluation framework, generating cross-orbit link evaluation information, analyzing parameters such as link quality and bandwidth, obtaining current service demand information, analyzing a communication resource allocation strategy in combination with a cross-orbit link evaluation result, and formulating a resource scheduling strategy according to strategy analysis. And a high-orbit and low-orbit satellite communication network is constructed through execution of a hierarchical network management mechanism and a cross-orbit data transmission protocol.

An intention-driven low-orbit satellite network SRv6 routing management and control method comprises the following steps: step 1, receiving and analyzing a user service demand from an application layer, and generating a corresponding intention label according to a service type; step 2, collecting state information of a satellite network in real time, tracking and recording satellite node position change and link state conversion, and establishing a complete network state database; 3, calculating a routing path meeting the service quality requirement by adopting an improved breadth-first search algorithm; 4, monitoring the state change of the inter-satellite link in real time; step 5, continuously monitoring fault events in the network, immediately starting a pre-calculated standby path when a fault is detected, updating a corresponding SRv6SID list, and performing rapid path switching; and step 6, dynamically adjusting the network flow. The method not only can adapt to the dynamic characteristics of the low earth orbit satellite network, but also can effectively meet the differentiated service requirements, and has the rapid fault recovery and load balancing capability.

The invention discloses a multi-satellite network converged communication link optimization and anti-interference method, which belongs to the technical field of wireless communication networks, and comprises the following steps: acquiring Doppler frequency shift parameters of satellite nodes, adjacent satellite radiation quantity parameters and preset geographical shielding coefficients, and generating a link dynamic quality coefficient; constructing a dynamic topological graph according to the link dynamic quality coefficient; performing radio frequency fingerprint extraction and frequency domain waveform phase reversal processing on the detected interference signal to generate an anti-interference compensation signal; and when the link dynamic quality coefficient is greater than or equal to a preset quality threshold value, selecting a target transmission path according to the dynamic topological graph, and injecting the anti-interference compensation signal into the target transmission path. According to the invention, a mechanism of cooperation of dynamic link quality evaluation, interference fingerprint feature matching and multi-path fragmentation transmission is adopted, and real-time optimization selection of communication paths, accurate suppression of interference signals and efficient distribution of network resources can be realized in a complex air and space environment.

The invention provides a multi-satellite cooperative distributed routing method for multi-agent reinforcement learning, and the method comprises the steps: building a satellite network static topology model through a time slicing technology, and building a target function for minimizing the end-to-end time delay of a data packet; constructing a satellite agent network based on the satellite network static topology model, and obtaining satellite interaction experience data; wherein the satellite agent network comprises a multi-satellite cooperative hybrid network and a satellite decision network corresponding to each agent; training a satellite agent network according to the satellite interaction experience data to obtain a trained satellite agent network; and respectively deploying the satellite decision networks in the trained satellite agent network to corresponding agents, so that the agents perform routing decision based on the deployed satellite decision networks. Through cooperative work of the satellite decision network and the multi-satellite cooperative hybrid network, efficient distributed routing decision of a low-orbit satellite constellation can be realized, time delay is reduced, and load is balanced.

The invention relates to a satellite network traffic spatio-temporal characteristic prediction method based on multiple convolutional neural networks, comprising the following steps: step 1, preprocessing input data including satellite network traffic data and satellite network topology information; 2, extracting spatial features, and processing a spatial dependency relationship of satellite network traffic through a GCN module; 3, time features are extracted, global features and local features of the satellite network traffic in the time dimension are extracted through a double-branch Transform encoder structure, the global branch processes long-term dependence through causal convolution and a global attention mechanism, and the local branch processes short-time mutation through dynamic convolution and a local attention mechanism; and 4, fusing the spatio-temporal features and output prediction, fusing the spatial features and the time features, and outputting a prediction result of the satellite network traffic through a linear layer. The accuracy and robustness of satellite network traffic prediction can be improved.

The invention discloses a data stream transmission scheduling method based on a distributed SDN satellite network, and the method comprises the following steps: building a distributed SDN satellite network model according to the application background of a large-scale satellite network, and constructing a data stream load balancing routing problem of the large-scale satellite network under the distributed SDN satellite network model; in order to solve the problem of data flow load balancing routing of a large-scale satellite network, a data transmission strategy of a distributed SDN satellite network is adopted, the load balancing effect is achieved, and end-to-end delay is reduced. According to the invention, a distributed SDN satellite network model is established according to the application background of a large-scale satellite network, a data flow load balancing routing problem of the large-scale satellite network is established under the model, and a data transmission strategy based on the distributed SDN satellite network is provided for the optimization problem. According to the strategy, a better load balancing effect and smaller end-to-end delay can be realized.

The invention provides an ocean buoy data real-time acquisition method based on low earth orbit satellite communication, and belongs to the technical field of electrical digital data processing.The ocean buoy data real-time acquisition method comprises the steps that firstly, a low earth orbit satellite network communication link is built, data characteristics are analyzed through a compression conversion gain index model, and a low earth orbit satellite network communication link is established; and establishing a multi-stage compression mechanism. The system adopts an optimization equation set to dynamically adjust compression parameters, the optimization equation set comprises a resource consumption equation, a compression quality equation and a transmission efficiency equation, and self-adaptive compression of data is achieved. And meanwhile, through a hierarchical algorithm selection mechanism and a parameter optimization strategy and in combination with real-time feedback control, continuous optimization of the compression efficiency is ensured. According to the compression scheme based on multi-level optimization, the technical problem of low compression efficiency caused by poor algorithm adaptability in the ocean buoy data compression process in the prior art is effectively solved.

The invention provides a multi-layer satellite network routing method and system based on multi-agent deep reinforcement learning. The method comprises the following steps that: a plurality of low-orbit satellites train respective executor networks by adopting a distributed multi-agent reinforcement learning algorithm to realize routing decision; and one medium-orbit satellite trains a global evaluation network according to the local parameters of the performer network uploaded by the plurality of low-orbit satellites, and provides the global parameters of the trained global evaluation network to each low-orbit satellite, so that the low-orbit satellites update respective local evaluation networks according to the global parameters. And updating respective executor networks according to the updated local evaluation network. According to the multi-layer satellite network routing method and system based on multi-agent deep reinforcement learning, dynamic optimization of a routing strategy can be realized in a medium and low orbit satellite network, and the overall performance of the satellite network is remarkably improved.

Various approaches for the generation and verification of user equipment (UE) location, using communications and processing capabilities of non-geostationary (NGSO) satellite networks and equipment are discussed. Among other examples, communications between a UE and a low-earth orbit (LEO) satellite may be used to substantiate or corroborate, to a location management function (LMF) of a 5G network, that a UE is located in or at a particular geographical location or area. Additionally, based on this location information and related SV ephemeris data, a satellite coverage area may be determined for a UE at a location at any one moment in time, for coordinating and managing connectivity of the UE with terrestrial and non-terrestrial networks.

The invention discloses a low earth orbit satellite network digital twin drive switching optimization method and system, and relates to the technical field of inter-satellite communication, and the method comprises the steps: building a digital twin system which is synchronously evolved with a physical LEO satellite network; predicting the link quality between each candidate satellite and the user terminal in a future time window based on a digital twin system; dividing a time window into a plurality of continuous time slices, constructing a directed weighted dynamic graph model which takes a satellite-time slice as a node and takes link comprehensive utility cost as an edge weight, and searching an optimal path in the directed weighted dynamic graph model by utilizing a shortest path algorithm so as to determine an optimal switching opportunity and a target satellite sequence; the optimal switching strategy is issued to a user terminal to be executed, and a link quality prediction result is corrected in real time through a feedback mechanism of the digital twin system to form closed-loop optimization; the method can effectively meet differentiated service quality requirements in a multi-service scene, and is suitable for a high-dynamic LEO satellite communication system.

The invention discloses a predictive topology-based satellite internet deterministic routing data plane migration method, which mainly solves the problem of data packet and service interruption during satellite switching in the prior art. According to the implementation scheme, service flow terminal equipment firstly sends an access request to an entrance edge node; the entry edge node calculates a tunnel path and resource reservation according to the request, performs service identification, encapsulates various identifiers into deterministic specific segment identifiers, and encapsulates the original data packet into an SRv6 data packet based on the tunnel path and the specific segment identifiers; when the service flow is transmitted in the satellite network, if a satellite is switched, service flow tunnel migration is carried out, and when a queue data packet exists in the switched satellite, queue cache migration is carried out. According to the invention, the forwarding of the service flow in the satellite switching process is not influenced, the flow interruption or transmission error caused by lack of information pre-synchronization in the traditional satellite switching is avoided, the priority transmission of the high-priority data packet is ensured, and the method can be used for data transmission between a ground terminal and a deterministic satellite network.

A wireless device sends, to a mobility management node via a base station of a satellite network, an indication of support for a store and forward (S&F) mode of operation. The wireless device receives, from the mobility management node, a de-registration timer parameter for the S&F mode.

The invention relates to the technical field of satellite network communication, and discloses a multi-source multi-path scheduling method for remote sensing data transmission, which comprises the following steps of: firstly, establishing an index table for remote sensing data by using a space-time name formed by a service type, an acquisition area, acquisition time, a node identifier and a data category; and the controller analyzes time and space constraints in the request, selects a plurality of source nodes meeting conditions from an index table, calculates priorities according to parameters such as residual bandwidth, round-trip delay and packet loss rate, and selects a plurality of non-overlapping high-quality paths. And then adding a service type, a path number, a path state report and a flow proportion field in the interest packet and the data packet, so that the source node sends segmented data in parallel according to a preset proportion. And the forwarding node reports the link change in real time, and the controller dynamically adjusts the path set and the shunt weight, thereby ensuring that the high-bandwidth and low-delay data transmission performance is continuously obtained in a topology and load rapid change scene.

The invention discloses a satellite route management and control switching method and system, and belongs to the field of satellite communication, and the satellite route management and control switching method comprises the following steps: monitoring satellite signal quality, collecting satellite data, judging whether nodes need to be switched or not, and if yes, switching the nodes; the triggering condition comprises that the signal quality decline is lower than a threshold value, and the communication equipment is about to break away from the current satellite network coverage range; when nodes need to be switched, an optimal switching target is selected from the candidate nodes, the signal quality of the optimal switching target is judged, and if the signal quality meets the use requirement, compared with the prior art, the method has the beneficial effects that when the coverage edge overlapping area of the multiple satellite networks is too small and the signal quality is judged to be poor, the optimal switching target is selected from the candidate nodes; according to the method, the switching node is limited, the random switching of the node is not allowed in the set time, the set time can be adjusted according to the actual condition, different conditions are matched, and the problems of communication quality degradation, network resource waste, terminal energy consumption increase and the like are reduced.

The invention discloses a time-varying routing method and system for a satellite internet, and mainly solves the problems that an existing satellite network routing method is difficult to support satellite high-quality communication, the topology is frequently changed, and the information communication load between satellites is heavy. According to the scheme, the method comprises the following steps: initializing orbit parameters of satellite nodes and an inter-satellite link set; obtaining a link on-off timetable through simulation, and sending the link on-off timetable to a satellite node by a ground station; the satellite node generates a topology prediction message according to the link on-off time table, determines the sending time of the message according to the difference value between the link change moment and the sending time of the routing control message, and floods the message in the limited area; and after receiving the message, the satellite node analyzes the link information to calculate a virtual route, arranges a route updating sequence of the satellite node, replaces the route table with the virtual route table at the link change moment, and issues the route to the basic network layer. According to the method, the transmission load of the network can be effectively reduced, the probability of outdated routing and packet loss is reduced, the method can be used for establishing the satellite internet, and the communication quality between satellites is guaranteed.

The invention discloses a satellite portable station data encryption authentication method and system, and belongs to the technical field of wireless communication network security, and the method comprises the steps: collecting power amplifier nonlinear harmonic spectrum data and environmental noise frequency domain energy distribution data of a satellite terminal, and carrying out the XOR confusion processing, and generating a dynamic key parameter; generating a cross-network authentication pre-distribution parameter based on a preset satellite link stability threshold and the signal quality parameter of the current satellite network; and when the signal quality parameter of the satellite network is reduced to a preset switching threshold, extracting a target network session key parameter, and encrypting and sending uplink data in combination with the dynamic key parameter and the cross-network authentication pre-distribution parameter. According to the invention, a power amplifier harmonic wave and environmental noise fusion key generation technology and a link stability and space-time parameter linkage pre-distribution mechanism are adopted, so that high-safety and low-delay communication protection can be realized in a complex electromagnetic environment and a multi-satellite network switching scene.

The invention discloses an internet constellation dynamic routing optimization method and system, and the method comprises the steps: setting orbit plane parameters and satellite parameters, and carrying out the modeling of an orbit and a constellation; performing link visualization and time-varying graph generation according to ephemeris data and the constructed constellation model; defining a related space, a network and a function based on a deep reinforcement learning algorithm; and based on an MADDPG framework, introducing a multi-agent collaborative decision-making mechanism, and outputting action selection and execution results after collaborative optimization. The system comprises a model construction module, an embedding module, a reinforcement learning design module and a collaborative optimization module. By using the method, the dynamic change of the low-orbit satellite network can be effectively dealt with, satellite resources are fully utilized, and efficient and reliable communication is realized. The method can be widely applied to the field of wireless communication.

The invention relates to the technical field of network security, in particular to a satellite network multi-dimensional threat simulation method and system based on isolated forest detection. The method comprises the following steps of: loading real-time traffic data of a satellite network through a data interface, extracting key indexes, recording traffic size, time delay and packet loss probability, and establishing an initialized traffic characteristic framework; according to the method, through accurate identification of the abnormal modes and comparison with known threat features, judgment of potential threats is more accurate, resource waste caused by misinformation is avoided, evaluation of multi-dimensional threat degrees and specific analysis of threat risks provide more comprehensive safety evaluation, defense measures are more targeted and efficient, and the method is suitable for popularization and application. And the defense configuration is adjusted, and the defense scheme is tested in the virtual environment, so that the effectiveness of the adjustment measure is further verified, the resistance of the satellite network to actual threats is ensured, and the adaptability of the defense configuration and the overall security of the network are remarkably improved.

A routing method for supporting differential service requirements in a satellite internet comprises the following steps: step 1, constructing multi-dimensional network state perception as a base layer which is responsible for collecting and quantifying physical states and logic states of a satellite network in real time, and obtaining objective network states and subjective QoS (Quality of Service) requirements of services; 2, generating a nonlinear adaptive weight driven by a service as a strategy layer, mapping an objective network state and a subjective QoS (Quality of Service) demand of the service, dynamically adjusting the value orientation of routing judgment, and generating a dynamic weight; and step 3, taking the dynamic cost routing decision as an execution layer, calculating the comprehensive cost based on the dynamic weight, and executing next hop selection and path maintenance, and through cooperative work of the dynamic cost routing decision, the comprehensive cost and the next hop selection and path maintenance, realizing intelligent path selection and high-reliability transmission for different service flows in a high-dynamic and resource-limited environment of the low-orbit satellite. According to the invention, while the routing computation overhead is effectively reduced, multiple requirements of differentiated services on low time delay and high reliability can be considered.

The invention relates to the technical field of satellite network communication, in particular to an ST-DSQN-based low earth orbit satellite network task unloading method and system, and the method comprises the steps: introducing a time flow module, a spatial flow module and a space-time attention mechanism into a deep Q network, and constructing a space-time double-flow Q network; the method comprises the following steps: extracting time characteristics of arrival of a satellite unloading task through a time flow module, extracting spatial characteristics of inter-satellite topology through a spatial flow module, and carrying out weighted summation on the time characteristics and the spatial characteristics based on a space-time attention mechanism to obtain space-time fusion characteristics; and inputting the space-time fusion features into the deep Q network, and training the deep Q network in combination with a priority experience playback mechanism and a multi-target reward function until an optimal task unloading strategy is learned. According to the method, space and time characteristics can be better combined, efficient decision-making of task unloading in the satellite network environment is achieved, the average time delay and energy consumption are remarkably reduced, and the task success rate is improved.

The invention relates to a dynamic routing and flow balancing method and system for a regionalized network topology, and the method comprises the steps: dividing a satellite network into a plurality of partitions, and distributing a core node for traffic scheduling and routing calculation for each partition; each core satellite node responds to each traffic demand, and bandwidth and traffic distribution in each partition are adjusted through a multi-anchor-segment routing method and a preset linear programming model; and each satellite node dynamically adjusts the route of each traffic demand through a probability forwarding scheduling method based on geometric topology according to the relative position of the satellite node and the target node. According to the method, low delay, high bandwidth utilization rate, load balance and efficient fault recovery of the satellite network are realized through network partitioning, a multi-anchor-segment routing method and probability forwarding based on geometric topology.

The invention relates to a satellite network distributed routing method, a satellite network distributed routing system, satellite network distributed routing equipment and a storage medium, belongs to the technical field of wireless communication, and solves the problems of dynamic topological structure change and overlarge load of part of nodes caused by non-uniform service volume distribution in the existing satellite network routing method. The satellite network distributed routing method comprises the following steps: firstly, modeling a routing problem, constructing a problem model, then defining a state space, an observation space, an action space and a reward function of a Markov decision process, constructing a DDQN-based satellite network routing algorithm training framework based on the Markov decision process, and constructing a satellite network routing algorithm training framework based on the DDQN. And then a satellite network routing algorithm training framework based on DDQN is utilized to realize satellite network routing decision, and the network load is reduced with the purpose of minimizing end-to-end delay. The method is not influenced by the dynamic change of the network topology, and can adapt to the frequent network topology change of the low-orbit satellite, thereby ensuring the real-time performance and robustness of data transmission.

An AI-driven wireless lubricator remote control system includes multiple grease injection lubrication devices, a cloud server host and an artificial intelligence (AI) system. Each grease injection lubrication device includes a central control processing unit, a grease injection lubrication unit, a parameter setting unit, an operating status information unit, a detection unit, a warning unit, a wireless communication unit and a remaining oil volume information unit. The grease injection lubrication device can independently monitor the oil supply status and abnormal operating status information of individual lubrication points, and through wireless remote transmission (network or satellite network), the grease injection lubrication device information distributed on the mechanical equipment scattered around the factory is sent to the cloud server host. Furthermore, the mobile device can view the information of each grease injection lubrication device and issue commands directly through APP and the Internet (connected to the cloud server host).

The invention provides a satellite constellation network topology state rapid sensing method. A multi-dimensional physical layer monitoring module, a dynamic adaptive BFD detection mechanism, an OSPF routing protocol and a shared data exchange area of a BFD driver and an OSPF process are deployed on each satellite node. According to the method, the connectivity of inter-satellite links is monitored in real time by using a physical layer signal state monitoring technology and the rapid link state detection capability of a BFD protocol, and related nodes are immediately notified through a control message when a fault is detected; meanwhile, the detection result of the BFD is linked with an OSPF routing protocol, and instant routing recalculation is triggered, so that the routing convergence time is shortened. A cross-layer closed-loop linkage system is constructed, a physical layer senses data to dynamically regulate and control protocol layer detection parameters, and hardware acceleration is combined to realize fault detection full-process optimization, so that the fault detection and recovery speed is accelerated, the resource utilization efficiency and the overall transmission efficiency of an inter-satellite network are improved, and the fault detection and recovery efficiency is improved. And high reliability and stability of the network are ensured.

The invention discloses a heterogeneous task low orbit satellite task unloading method based on a space-time diagram attention network. The method comprises the steps of obtaining space-time diagram data related to a to-be-unloaded task; the time-space diagram data are input into a time-space conversion model, a prediction result of a subsequent network state is obtained, the time-space conversion model integrates a graph convolutional network module, a long-short-term memory network module and a multi-head attention module, the graph convolutional network module extracts spatial features of satellite network topology under each time step, and the multi-head attention module extracts the spatial features of the satellite network topology under each time step; the long-short-term memory network module captures satellite network states and time sequence dependence of task loads, and the multi-head self-attention module learns association weights among different spatial-temporal characteristics and outputs prediction results of future satellite network states; and based on the prediction result and the attribute of the to-be-unloaded task, setting an optimization objective function of an opportunity task unloading algorithm problem to determine a decision result of task unloading. According to the method, the task unloading efficiency and the resource utilization rate in the low-orbit satellite network can be remarkably improved.

The invention relates to the technical field of satellite routing, and discloses a spatial three-dimensional satellite routing method, device and system, and the method comprises the steps: constructing a spatial satellite network based on LEO, MEO and GEO three-layer satellite nodes; performing orbit mechanical prediction calculation based on a space satellite network to obtain a link state prediction matrix; inputting the link state prediction matrix into a spatial position coding processor for processing to obtain a spatial time-varying routing graph; generating a routing strategy of the satellite nodes based on the space time-varying routing graph; according to the method, global optimization of end-to-end time delay and energy consumption is achieved under the condition that the network capacity and the link availability are met, and then the cross-track data transmission efficiency is improved.

The invention discloses a large-scale low-orbit satellite network domain-division intelligent routing method, which belongs to the technical field of satellite communication, and comprises the following steps: constructing a network model based on multi-dimensional resource characteristics, and providing resource constraint conditions and space-time correlation characteristics for routing decision by combining with a regional flow prediction algorithm of an improved Transform architecture; virtual nodes and an autonomous domain are divided based on a geographic area, and a low-orbit satellite network routing process is decoupled into an intra-domain part and an inter-domain part; a multi-agent deep Q network is adopted in a domain, a sum tree mechanism-based deep Q network is adopted between domains, a routing algorithm and a resource scheduling algorithm are respectively designed, and a domain intelligent routing system with flexibility and expandability is constructed through hierarchical routing and resource decoupling scheduling. According to the method, the service capability of the low earth orbit satellite network in extreme scenes such as topology high-frequency change, strict resource limitation and traffic space-time mutation is remarkably enhanced, and a high-reliability and low-delay routing solution is provided for space-ground integrated communication, emergency disaster early warning and global real-time data transmission.

The invention discloses an access authentication method and device, a satellite network system and a storage medium. The method comprises the following steps: receiving an authentication request containing an access request plaintext of a user terminal sent by at least one first node in a previous layer of a network node through a non-secure channel; performing multiple verification on each received authentication request; wherein the multiple verifications comprise verifying the timeliness and the non-tampering property of the authentication request received by the network node, and verifying the legality of each node in the access request path before the access request plaintext reaches the network node; and aggregating all the authentication requests passing the multiple verifications into a new authentication request, and sending the new authentication request to a second node in the next layer of the network node until the request plaintext reaches the network control center, so that the network control center generates unified authentication response information for all the user terminals corresponding to the authentication requests passing the multiple verifications in the network control center. And the session keys are distributed to the corresponding user terminals, so that the corresponding user terminals generate the session keys.

The invention discloses a signal countering intelligent monitoring system of an unmanned aerial vehicle, which relates to the technical field of signal countering and comprises a multi-source acquisition module, a dynamic verification module, a decision analysis module, an intelligent communication module, an integrated radar unit, a spectrum analysis unit, an infrared sensing unit and a sound wave detection unit. Multi-source data fusion is realized through the data association evaluation value, the signal countering effect of the unmanned aerial vehicle is improved through the threat evaluation value R, the hierarchical threat response and the precise matching countering strategy, and when the radar signal intensity normalization value S1 conflicts with the infrared feature matching degree S3, the verification value is calculated according to the voiceprint matching degree S4 and the spectrum matching degree S2, so that the reliability of the unmanned aerial vehicle is improved. Or a standby unmanned aerial vehicle signal recognition system is started for synchronous detection, multi-source data contradiction is solved, the misjudgment rate is reduced, satellite, 5G and Mesh network dynamic switching is achieved, the communication performance of the system is guaranteed through a priority strategy, and the data transmission delay rate is reduced.

The invention discloses a satellite communication method and system based on multi-orbit fusion networking, and the method comprises the steps: determining the network type of a target satellite based on the orbit position and working mode of the target satellite and the position of a base station paired with the target satellite, corresponding indication information is generated based on the network type, the current state of the target satellite and parameters related to the state; the indication information is provided for the terminal currently connected with the target satellite through the target satellite; the rail position comprises any one of a low rail, a middle rail and a high rail; the working mode comprises any one of a transparent forwarding mode and a regeneration mode; the positions of the base stations include the positions on the ground and satellites on different orbits. Based on the above communication method, the terminal can be ensured to more accurately access, switch, service and the like of the satellite network, meanwhile, through multi-track fusion networking, the interaction capability of the communication satellite and the terminal is enhanced, the network collaborative coverage capability of the communication satellite and the utilization rate of a base station are improved, and the network cost can be reduced.