A load balancing dynamic access method under multi-satellite coverage

Abstract

The application discloses a load balancing dynamic access method under multi-satellite coverage, which comprises the following steps: classifying user terminal services according to QoS requirements on the user side, generating a service multi-target utility function according to service indexes, and generating multi-target weight coefficients according to the importance of different services; constructing a terminal visible satellite set and an adjacent satellite set of each satellite on the satellite side, and proposing a load balancing degree parameter and a load adjustment method of the terminal visible satellite set and the adjacent satellite set of each satellite, so that the satellite network corresponding to the current user terminal can reach dynamic load balancing within a certain time. The method can meet the multi-target requirements of different types of services of the ground user terminal, consider the actual capacity of the satellite network, and make the satellite network corresponding to the current user terminal reach local dynamic load balancing within a certain time and a certain range, and can be applied to low-orbit satellite network service access such as China Star Network.

Description

Technical Field

[0001] This invention relates to the field of network and information processing, and specifically to a dynamic access method for load balancing under multi-satellite coverage. Background Technology

[0002] Because low-Earth orbit (LEO) satellite constellations need to provide seamless global satellite communication services, the number of LEO satellites will inevitably increase significantly, leading to a substantial increase in multi-satellite coverage for ground user terminals. For example, the GlobalStar communication system achieves a 90% coverage rate with just two satellites. Currently, with the rapid increase in the number of satellites in planned LEO constellations, user terminals will generally be located in overlapping coverage areas. User terminals within these overlapping areas can simultaneously receive broadcast information from multiple satellites within a certain timeframe. Therefore, user terminals in these overlapping areas face the challenge of access selection under multi-satellite coverage. Furthermore, when a user terminal leaves the coverage area of ​​its currently connected communication node, it needs to switch to the next satellite communication node to ensure service continuity. Whether it's a new call access or a call handover, user terminals face the access selection problem under multi-satellite coverage. Simultaneously, user terminal access presents a dynamic load balancing issue for the satellite network. Distributed dynamic load balancing of the satellite network can be achieved by obtaining network load information for a certain range of satellites.

[0003] Existing research has proposed access selection methods for multi-satellite coverage satellite networks, mainly focusing on the following aspects: For satellite parameters corresponding to service indicators, such as satellite-to-ground distance, satellite service time, and remaining satellite load, the impact of service access on load balancing, and the impact of load balancing-related parameters on service access, are not considered. For multi-service intelligent access selection strategies, state variables, action spaces, and feedback functions are designed for dual-satellite coverage scenarios. This method assumes that each satellite can obtain global state information of the satellite network, resulting in high computational complexity and long convergence time, which is not conducive to dynamic load balancing on satellites. For service QoS requirements in high- and low-Earth orbit satellite networks, satellite transmission delay, delay jitter, and cost are used as weighting values ​​to calculate the comprehensive weighted value of service QoS and the load value of the satellite set. However, this only considers the load value of the accessible satellite set and does not judge the load balancing situation of visible satellites and related local satellite networks, nor does it perform corresponding load balancing adjustments. Summary of the Invention

[0004] The technical problem solved by this invention is as follows: Addressing the comprehensive access requirements for service QoS and satellite network load balancing performance in multi-satellite coverage scenarios, and overcoming the difficulty of satellites obtaining real-time global resource usage information, this invention proposes a dynamic load balancing access method under multi-satellite coverage. Based on the importance of satellite parameters corresponding to the user-side terminal service QoS requirements and satellite load usage, a terminal service access objective function based on weight coefficients and load adjustment factors is constructed, simultaneously considering user terminal service requirements and satellite network load balancing characteristics. The invention proposes constructing two satellite sets on the satellite side: a visible satellite set and a neighboring satellite set. By adjusting the load balancing parameters of these two satellite sets, local dynamic load balancing can be achieved for the satellite network corresponding to the current user terminal within a certain time and range.

[0005] The technical solution provided by this invention is as follows:

[0006] A dynamic access method for load balancing under multi-satellite coverage includes: classifying user terminal services according to QoS requirements on the user side, generating a multi-objective utility function for services based on service indicators, and generating multi-objective weight coefficients for the importance of different services; constructing a set of satellites visible to the terminal and a set of adjacent satellites for each satellite on the satellite side, proposing load balancing parameters and load adjustment methods for the set of satellites visible to the terminal and the set of adjacent satellites for each satellite, so that the satellite network corresponding to the current user terminal achieves dynamic load balancing within a certain period of time.

[0007] Optional, specifically including the following steps:

[0008] Step 1, Ground User Terminal (UE) j A service utility function f is generated based on the service indicators and their corresponding satellite-to-ground distance, satellite service time, and satellite load utilization parameters. j The subscript j indicates the label of different ground user terminals, specifically:

[0009] f j =α j f 1j +β j f 2j +γ j f 3j ;

[0010] Where, α j ,β j ,γ j These are the weighting coefficients for the parameters of satellite-to-ground distance, satellite service time, and satellite payload utilization, respectively. 1j The satellite-to-ground distance utility function, f 2j The satellite service time utility function, f 3j A utility function characterizing satellite load balancing;

[0011] Step 2, LEO satellite i Calculate the current local load utilization rate based on the local physical channel resource block load. The subscript 'i' indicates different satellite designations, which are calculated as follows;

[0012]

[0013] Where n represents the different services offered by the satellite. This represents the number of resource blocks occupied by the nth service at time t in the current satellite. This represents the sum of the number of resource blocks occupied by all services at the current satellite time t. This indicates the number of services that the satellite is currently accessing at time t. This represents the total number of resource blocks currently available to the satellite;

[0014] ρ h To characterize the satellite load utilization threshold, if the satellite LEO i If the current load utilization rate is greater than or higher than this threshold, the satellite cannot access any new services; otherwise, it can.

[0015] Step 3: Define the LEO satellite i The set of adjacent satellites at time t, K represents satellite LEO. i The number of adjacent satellites, where K+1 is the set. The number of satellites in the middle,

[0016] The variance of satellite load utilization is used to characterize the dispersion of satellite load utilization. (Satellite ensemble) Satellite payload utilization variance Var LEO (t), is the average of the squared differences between each value in the set and the mean, Var. LEO (t) is obtained, and the calculation formula is as follows:

[0017]

[0018] Where K+1 is a set The number of satellites in the middle, This represents the average payload utilization of all satellites in the satellite ensemble; satellite ensemble Satellite load utilization variance threshold The variance threshold of satellite load utilization in the satellite set calculated at time t is used as a threshold to measure the satellite load balance.

[0019] Step 4, User Terminal (UE) jReceive satellite broadcast signals to obtain the set of visible satellites at time t. Defined as I is a set The number of satellites in the middle,

[0020] Step 5: The ground user terminal determines whether the currently accessible satellites meet the service requirements based on the satellite side feedback parameters, and sets the satellite load adjustment factor li. Based on the satellite load utilization rate feedback from the satellite side, the value of parameter li is adjusted.

[0021] Step 6: Normalize the satellite-to-ground distance, satellite service time, and satellite load utilization rate indicators, and then apply the utility function weighting coefficient α. j ,β j ,γ j Calculate the utility function values ​​of satellites within the visible satellite set;

[0022] Step 7: Define the satellite objective function as F j =α j f 1j +β j f 2j +γ j f 3j ·l j According to the satellite load adjustment factor l obtained in step 5 i and the satellite utility function value f obtained in step 6 1j ,f 2j ,f 3j Calculate the target value of accessible satellites; select the satellite corresponding to the maximum target value as the optimal access satellite;

[0023] Step 8, LEO satellite i After receiving the service request message and successfully accessing the network, update the local physical channel resource block load status and the load utilization parameter. and the variance of load utilization of adjacent satellite sets (Var) LEO (t) information.

[0024] Optionally, step 1 specifically includes:

[0025] Step 1a: List the importance of service utility function parameters under different ground user terminal service types. The importance of service utility function parameters can be divided into five levels: extremely high, high, medium, average, and low.

[0026] Step 1b: Use the analytic hierarchy process (AHP) to analyze the importance of satellite-to-ground distance, satellite service time, and satellite load utilization for different services; define different importance scales for the three types of service indicators and map them to different importance scales from 1 to 9.

[0027] Step 1c: Based on the indicator importance scales given in Steps 1a and 1b, calculate the importance of the utility function parameters for voice services, streaming media services, interactive services, and back-end services, respectively.

[0028] Step 1d: Calculate the weight coefficients for different business functions using the Analytic Hierarchy Process (AHP). First, obtain the normalized weight of each column for each indicator, and then calculate the average value of each indicator row by row to obtain the utility function weight coefficients α for different business functions. j ,β j ,γ j .

[0029] Optional, satellite load utilization variance threshold The settings include:

[0030] Set satellite load utilization The range is [0, ρ h ], ρ h Given a predefined satellite load utilization threshold, and K+1 load utilization values ​​in the set; given the number of values ​​in the set and their range, find the maximum value of the load utilization variance, max(Var). LEO The corresponding set of values ​​contains only the maximum value ρ. h The dispersion is highest when the minimum value is 0; when the maximum numerical difference in the set is less than ρ h When the value is 2, it indicates that the load balancing is relatively good. When the difference in the largest data value in the set is greater than or equal to ρ, the load balancing is relatively good. h When the value is / 2, it indicates that the load balancing is weak and load balancing adjustment is needed; the load utilization set is defined as having a value range of [0, ρ]. h / 2], the satellite load utilization value is only taken as the maximum value ρ. h The variance calculated from / 2 and the minimum value of 0 is the maximum variance of the set. This serves as a threshold for measuring satellite load balancing.

[0031] Optionally, step 6 specifically includes:

[0032] Step 6a: The ground user terminal obtains the range of low-Earth orbit satellite distances [D] based on prior knowledge. min D max And the current distance D between the user terminal and the satellite. ij D min ≤D ij ≤D max ,but

[0033]

[0034] Calculate the set of satellites that can be accessed for the service separately. The function value f of the satellite1j ;

[0035] Step 6b: The ground user terminal obtains the satellite's service time range [Ts] based on prior knowledge such as ephemeris. min ,Ts max And the current terminal and satellite service availability time Ts i,j Ts min ≤Ts i,j ≤Ts max ,but Calculate the set of satellites that can be accessed for the service separately. The function value f2j of the satellite;

[0036] Step 6c: The ground user terminal receives the current load utilization parameters fed back by the satellite. calculate Calculate the set of satellites that can be accessed for the service separately. The function value f3j of the satellite.

[0037] Optionally, step 5 specifically includes:

[0038] Step 5a: First, the user terminal determines the currently accessible satellite set. Based on the load situation, determine the available load utilization rate of satellites in this set in turn. Does it meet the current business load requirements? If yes, proceed to step 5c; otherwise, proceed to step 5b.

[0039] Step 5b, in the satellite assembly If the satellite is deleted, proceed to step 5c. If the updated satellite set... If it is an empty set, proceed to step 5g;

[0040] Step 5c, Updated Satellite Set Calculate the updated satellite set Load utilization variance Var L ′ EO (t), and calculate according to the satellite load utilization variance threshold calculation method. Satellite load utilization variance threshold Among them, Var′ LEO (t) and Refer to Var in step 3 LEO (t) and The calculation method;

[0041] Step 5d: Determine the variance of load utilization Var′ LEO Is (t) greater than or equal to the load utilization variance threshold? If the value is greater than or equal to the threshold, proceed to step 5e;

[0042] Receive updated satellite set The set of adjacent satellites for each satellite Load utilization variance Var LEO (t), determine its relationship with the load utilization variance threshold calculated in step 4. If the value is greater than or equal to the threshold, proceed to step 5e;

[0043] If the variance of resource utilization of both satellite sets is less than the corresponding threshold value, proceed to step 5f;

[0044] Step 5e: The satellite's load adjustment factor needs to be adjusted. i ;l i The default value is 1, and the numerical range is defined as [0,2]. The satellite load utilization rate can be divided into [0,ρ]. h / 2] and [ρ h / 2,ρ h Comparison of satellite sets Utilization of each satellite With ρ h The size of / 2;

[0045] like This indicates that the satellite's load is too low, and the load adjustment factor 1 needs to be increased. i Increase the target value for satellite access, l i The adjustment factor is:

[0046] like This indicates that the satellite has a large load and the load adjustment factor needs to be reduced. i Reduce the target value for satellite access, l i The adjustment factor is:

[0047] Step 5f: No need to adjust the satellite's load adjustment factor l i ;

[0048] Step 5g: No suitable satellites are available. Please wait for the next time period to select again.

[0049] The advantages of this invention compared to the prior art are:

[0050] (1) This invention maps the QoS indicator requirements of user-side terminal services to the importance of satellite parameters, constructs a multi-objective utility function of terminal services based on weight coefficients and load adjustment factors, and constructs a satellite access objective function based on the load balancing parameters of the two types of satellite sets on the satellite side, so as to meet the QoS requirements of low-orbit satellite network services while comprehensively considering the load balancing requirements of satellite network.

[0051] (2) This invention adjusts the load balancing influence factor of the satellite network by judging the magnitude of the load utilization variance and the load utilization variance threshold in the visible satellite set and the adjacent satellite set, so that the satellite network corresponding to the current user terminal within a certain time and a certain range can achieve local dynamic load balancing. Attached Figure Description

[0052] The accompanying drawings are provided to further illustrate the present disclosure and form part of the specification. They are used together with the following detailed description to explain the present disclosure, but do not constitute a limitation thereof. In the drawings:

[0053] Figure 1 Flowchart of dynamic access for load balancing under multi-satellite coverage;

[0054] Figure 2 Flowchart of satellite load adjustment factor calculation;

[0055] Figure 3 A diagram illustrating a multi-satellite coverage scenario and a satellite array. Detailed Implementation

[0056] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments. The following embodiments are for illustrative purposes only and should not be construed as limiting the scope of the invention.

[0057] This invention proposes a dynamic load-balanced access method under multi-satellite coverage. On the user side, terminal services are categorized according to QoS requirements. A multi-objective utility function is generated based on parameters such as satellite-to-ground distance, service time, and satellite load utilization corresponding to service indicators. Multi-objective weight coefficients are also generated based on the importance of the indicators to different services. On the satellite side, two types of satellite sets are constructed: the set of satellites visible to the terminal and the set of adjacent satellites for each satellite. Load balancing parameters and load adjustment methods for these two types of local satellite sets are proposed, enabling dynamic load balancing of the satellite network corresponding to the current user terminal within a certain time period. This invention satisfies the multi-objective requirements of different types of services from ground user terminals while also considering the dynamic load balancing requirements of satellite sets.

[0058] On the user side, terminal services can be categorized according to QoS requirements. Specifically, QoS service requirements refer to latency requirements, latency jitter requirements, and packet loss rate requirements. These service categories mainly include four types: voice services, streaming media services, interactive services, and backend services. Among these, voice services are more sensitive to latency, streaming media services are more sensitive to latency jitter and packet loss rate, and backend and interactive services are more sensitive to packet loss rate.

[0059] In low-Earth orbit (LEO) satellite networks, latency (primarily transmission latency) is mainly related to the satellite-to-ground transmission distance; latency jitter is mainly related to the difference in satellite data stream processing queuing time and satellite service availability, and in the access stage, it is mainly related to the satellite customer service duration; packet loss rate is related to satellite-to-ground channel quality, processing queuing time, and satellite load rate. Based on the QoS requirements of terrestrial user services, the importance of three types of parameters—satellite-to-ground distance, satellite service availability, and satellite load utilization—to different services is listed.

[0060] In this invention, 't' refers to a specific time point, indicating that the information is related to time but not to the unit of time. The following is a representation of the meaning of each letter in this invention:

[0061] UE j : Represents the ground user terminal, where the subscript j indicates the different terminal number.

[0062] LEO i : Represents the satellites visible at a certain terminal time t, where the subscript i indicates different satellite labels.

[0063] Characterizing the user terminal (UE) j The set of visible satellites at time t

[0064] I is a set The number of satellites in the middle,

[0065]

[0066] Characterizing the ground user terminal (UE) j The set of visible satellites updated at time t.

[0067] Characterization satellite LEO i The set of adjacent satellites at time t, K represents satellite LEO. i The number of adjacent satellites, where K+1 is the set. The number of satellites in the middle,

[0068] LEO satellite time t i The sum of the time-domain and frequency-domain physical resource blocks used by the accessed services is used as the numerator, and the satellite LEO is used as the numerator. i The total number of available physical resource blocks is used as the denominator to characterize the satellite's load utilization rate.

[0069]

[0070] in, This represents the number of resource blocks occupied by the nth service at time t in the current satellite. This represents the sum of the number of resource blocks occupied by all services at the current satellite time t. This parameter represents the total number of resource blocks currently available to the satellite. A high value indicates a heavy load, requiring a reduction in access traffic; conversely, a low load allows for an increase in access traffic. 'n' represents the different services offered by the satellite.

[0071] ρ h This represents the maximum load utilization threshold of a satellite under normal conditions; the subscript h is an abbreviation for high. If the satellite has a LEO rating... i If the load utilization rate at time t is greater than or above this threshold, the satellite cannot accept any new services. (This value is constant and is not related to time t.)

[0072] Var′ LEO (t): Represents the set of visible satellites updated at time t. The variance of satellite load utilization.

[0073] The updated set of visible satellites calculated at time t The variance threshold of satellite load utilization.

[0074] Var LEO (t): Represents the set of adjacent satellites at time t. The variance of satellite load utilization.

[0075] The set of adjacent satellites calculated at time t The variance threshold of satellite load utilization.

[0076] α j ,β j ,γ j : Representing the user terminal UE j The weight parameters are based on three objective functions: satellite-to-ground distance, satellite service availability, and satellite load balancing. The subscript j represents different user terminals.

[0077] l i LEO satellite i The load adjustment factor. When the set After the satellite calculates the effect value based on the service utility function, the final effect value of each satellite needs to be adjusted according to the load adjustment factor.

[0078] f j User terminal (UE) j The service utility function f that needs to be calculated when accessing satellites. j =α j f1j +β j f 2j +γ j f 3j , where f 1j The satellite-to-ground distance utility function, f 2j The satellite service time utility function, f 3j A utility function characterizing satellite load balancing.

[0079]

[0080] F j User terminal (UE) j Accessible satellite objective function F j =α j f 1j +β j f 2j +γ j f 3j ·l j , l i Used to correct f 3j Utility function.

[0081] [D min D max ]: Range of distances between low-Earth orbit satellites and the ground.

[0082] D ij : Current distance between the terminal and the satellite, D min ≤D ij ≤D max .

[0083] [Ts min ,Ts max [: The range of time during which the satellite can provide service.]

[0084] Ts i,j : Current terminal and satellite service availability time, Ts min ≤Ts i,j ≤Ts max

[0085] Combination Figure 1 The load balancing dynamic access method under multi-satellite coverage of the present invention comprises the following steps:

[0086] Step 1: First, the ground user terminal generates a service utility function f based on the service indicators and their corresponding satellite-to-ground distance, satellite service time, and satellite load utilization parameters. j =α j f 1j +β j f 2j +γ j f 3j, where α j ,β j ,γ j These are the weighting coefficients for the parameters of satellite-to-ground distance, satellite service time, and satellite payload utilization, respectively. 1j ,f 2j ,f 3j The numerical values ​​of the business utility function parameters are represented separately, and the weight coefficients of the business utility function are generated using the analytic hierarchy process (AHP).

[0087] Step 1a: List the importance of service utility function parameters under different ground user terminal service types. The importance of service utility function parameters can be divided into five levels: extremely high, high, medium, average, and low.

[0088] Table 1 Importance of Business Characteristics

[0089]

[0090] Note: Table 1 only provides an example of importance; the importance can be adjusted according to business requirements.

[0091] Step 1b: Use the analytic hierarchy process (AHP) to analyze the importance of satellite-to-ground distance, satellite service availability, and satellite load utilization for different services. First, define importance scales for different indicators, mapping the three types of service indicator parameters to different importance levels from 1 to 9.

[0092] Table 2. Indicator Importance Scale

[0093] Scale Meaning of scale difference 1 This indicates that the two indicators are equally important. 3 This indicates that one of the two indicators is slightly more important than the other. 5 This indicates that one of the two indicators is more important than the other. 7 This indicates that one indicator is significantly more important than the other. 9 This indicates that one of the two indicators is far more important than the other. 2,4,6,8 The median of the two adjacent judgments above reciprocal If the scale of index A is 3 compared to index B, then the scale of B compared to A is 1 / 3.

[0094] Step 1c: Based on the indicator importance scales given in Steps 1a and 1b, calculate the importance of the utility function parameters for different types of services, including voice services, streaming media services, interactive services, and back-end services.

[0095] Step 1d: Calculate the weight coefficients for different business functions using the Analytic Hierarchy Process (AHP). First, obtain the normalized weight of each column for each indicator, and then calculate the average value of each indicator row by row to obtain the utility function weight coefficients α for different business functions. j ,β j ,γ j .

[0096] Step 2, LEO satellite i Calculate the current local load utilization parameter based on the local physical channel resource block load. The calculation method is as follows.

[0097] LEO satellite time t i The sum of the time-domain and frequency-domain physical resource blocks used by the accessed services is used as the numerator, and the satellite LEO is used as the numerator. iThe total number of available physical resource blocks is used as the denominator to characterize the satellite's load utilization rate.

[0098]

[0099] in, This represents the number of resource blocks occupied by the nth service at time t in the current satellite. This represents the sum of the number of resource blocks occupied by all services at the current satellite time t. This indicates the number of services that the satellite is currently accessing at time t. This parameter represents the total number of resource blocks currently available to the satellite. A high value indicates a heavy load, requiring a reduction in access traffic; conversely, a low load allows for an increase in access traffic.

[0100] ρ h : Characterizes the threshold for satellite load utilization. If the satellite LEO i If the current load utilization rate is greater than or higher than this threshold, the satellite cannot connect to any new services.

[0101] Step 3, LEO satellite i Collect data on the load utilization of its adjacent satellites and calculate the variance of satellite load utilization Var within this set. Lin (t), and the satellite load utilization variance threshold Used to measure the load balancing of the satellite ensemble;

[0102] Define satellite LEO i LEO (Landing over Oxygen) satellites in (t)={LEO i ,LEO1,…,LEO n}, n≤N, where n is the number of satellites LEO i The number of adjacent satellites.

[0103] LEO satellite i There are two ways to obtain the load utilization of its adjacent satellites: one is to define the set as the LEO of the satellites. i There are two approaches: 1) A set of satellites with inter-satellite links. In this approach, satellite status information is exchanged via inter-satellite links to obtain load information related to adjacent satellites. 2) The set is defined as a set of satellites within a certain spatial distance. In this approach, satellites may not necessarily have inter-satellite links. The ground station receives satellite load status information and periodically sends load utilization information of the adjacent satellite set to each satellite.

[0104] Satellite load utilization variance: The variance of satellite load utilization is used. Lin (t) characterizes the dispersion of satellite load utilization, and is obtained by averaging the squares of the differences between each value in the set and the mean, as shown in the following formula:

[0105]

[0106] Satellite load utilization variance threshold Set satellite load utilization The range is [0, ρ h ], ρ h For the set satellite load utilization threshold, for Given the mean and the number of load utilization values ​​in the set (n), find the maximum value of the variance of the load utilization, max(Var). Lin The corresponding set of values ​​only contains the maximum value ρ. h The minimum value is 0, at which point the dispersion is highest; when the maximum numerical difference in the set is less than ρ... h When the value is 2, it indicates that the load balancing is relatively good. When the difference in the largest data value in the set is greater than or equal to ρ, the load balancing is relatively good. h When the value is 2, it indicates that the load balancing is weak and load balancing adjustments are needed. The load utilization set is defined as having a numerical range of [0, ρ]. h / 2], and the variance corresponding to the value taking only the maximum and minimum values ​​is the maximum variance of the set. This serves as a threshold for measuring satellite load balancing.

[0107] It is evident that the variance threshold for the load utilization of a satellite set needs to be calculated based on the current availability of satellites, while the variance threshold for the load utilization of adjacent satellite sets is calculated based on the availability of adjacent satellites. Assuming each satellite has the same number of adjacent satellites, since the load utilization thresholds are the same, the variance thresholds for the load utilization of adjacent satellite sets are also the same. This invention presents only two types of load utilization variance thresholds.

[0108] Step 4: The ground user terminal receives broadcast signals from the satellite, including satellite identification information and the current satellite network load utilization rate. LEO satellite i Variance of load utilization of adjacent satellite sets (Var) Lin Information such as (t) can be used to calculate the current satellite-to-ground distance and available service time of the corresponding satellite, thus simplifying satellite-to-ground communication.

[0109] User terminal UE j Receive satellite broadcast signals to obtain relevant parameters of visible satellites at time t. Define the user terminal (UE). j Visible satellite set Where k is the number of satellites in the set.

[0110] Combination Figure 2Step 5: The ground user terminal determines whether the currently accessible satellites meet the service requirements based on the satellite-side feedback parameters, and sets the satellite load adjustment factor l. i Based on the satellite load utilization feedback from the satellite side, adjust parameter l i Numerical value.

[0111] The satellite network load adjustment method and steps are as follows:

[0112] The ground user terminal determines whether the currently accessible satellites meet service requirements based on the parameters fed back from the satellite side, and sets the satellite load adjustment factor l. i Based on the satellite load utilization feedback from the satellite side, adjust parameter l i Numerical value.

[0113] Step 5a: First, the user terminal determines the currently accessible satellite set. Based on the load situation, determine the available load utilization rate of satellites in this set in turn. Does it meet the current business load requirements? If yes, proceed to step 5c; otherwise, proceed to step 5b.

[0114] Step 5b, in the satellite assembly If the satellite is deleted, proceed to step 5c. If the updated satellite set... If it is an empty set, proceed to step 5g;

[0115] Step 5c, Updated Satellite Set Calculate the updated satellite set according to formula 2 in step 3. Load utilization variance Var Lik (t), and calculate according to the satellite load utilization variance threshold calculation method in step 3. Satellite load utilization variance threshold

[0116] Step 5d: Determine the load utilization variance Var Lik Is (t) greater than or equal to the load utilization variance threshold? If the value is greater than or equal to the threshold, proceed to step 5e;

[0117] Receive updated satellite set The set of adjacent satellites for each satellite Load utilization variance Var Lin (t), determine its relationship with the load utilization variance threshold calculated in step 4. If the value is greater than or equal to the threshold, proceed to step 5e;

[0118] If the variance of resource utilization of both satellite sets is less than the corresponding threshold value, proceed to step 5f;

[0119] Step 5e: The satellite's load adjustment factor needs to be adjusted. i ;

[0120] l i The default value is 1, and the numerical range is defined as [0,2]. The range of satellite load utilization values ​​can be divided into... and [ρ h / 2,ρ h Comparison of satellite assemblies Utilization of each satellite With ρ h The size of / 2;

[0121] like This indicates that the satellite's load is too low, and the load adjustment factor 1 needs to be increased. i Increase the target value for satellite access, l i The adjustment factor is:

[0122] like This indicates that the satellite has a large load and the load adjustment factor needs to be reduced. i Reduce the target value for satellite access, l i The adjustment factor is:

[0123] Step 5f: No need to adjust the satellite's load adjustment factor l i ;

[0124] Step 5g: No suitable satellites are available. Please wait for the next time period to select again.

[0125] Step 6: Normalize the satellite-to-ground distance, satellite service time, and satellite load utilization rate indicators, and then apply the utility function weighting coefficient α. j ,β j ,γ j Calculate the utility function values ​​of satellites within the visible satellite set.

[0126] Step 6a: The ground user terminal obtains the range of low-Earth orbit satellite distances based on prior knowledge such as ephemeris data [D]. min D max And the current distance D between the terminal and the satellite ij D min ≤D ij ≤D max ,but Calculate the set of satellites that can be accessed for the service separately. The function value f of the satellite 1j .

[0127] Step 6b: The ground user terminal obtains the satellite's service time range [Ts] based on prior knowledge such as ephemeris. min ,Ts max And the current terminal and satellite service availability time Ts i,j Ts min ≤Ts i,j ≤Ts max ,but Calculate the set of satellites that can be accessed for the service separately. The function value f of the satellite 2j ;

[0128] Step 6c: The ground user terminal receives the current load utilization parameters fed back by the satellite. calculate Calculate the set of satellites that can be accessed for the service separately. The function value f of the satellite 3j .

[0129] Step 7: Define the satellite objective function as F j =α j +f 1j +β j f 2j +γ j f 3j ·l j According to the satellite load adjustment factor l obtained in step 5 i and the satellite utility function value f obtained in step 6 1j ,f 2j ,f 3j Calculate the target value of accessible satellites. Select the satellite corresponding to the maximum target value as the optimal access satellite.

[0130] Step 8, LEO satellite i After receiving the service request message and successfully accessing the network, update the local physical channel resource block load status and the load utilization parameter. and the variance of load utilization of adjacent satellite sets (Var) Lin (t) information.

[0131] Example 1:

[0132] The specific embodiments of the load balancing dynamic access method under multi-satellite coverage of the present invention are as follows:

[0133] like Figure 3 The image shows a multi-satellite coverage scenario and a schematic diagram of the satellite array.

[0134] Combination Figure 1 and Figure 2 The specific process involves setting the ground user terminal parameters: configuring the ground user terminal (UE). jThere are four types of transmission services: voice service 1, streaming media service 2, interactive service 3, and back-end service 4. Their resource requirements (calculated according to the proportion of satellite resources) are: {0.001, 0.005, 0.0001, 0.0005}.

[0135] Ground User Terminal (UE) j The visible satellite set is This includes satellite nodes {A, B, C}.

[0136] Configure satellite network parameters:

[0137] Star-to-Earth distance range: [D min D max ] = [600km, 1200km];

[0138] Satellite nodes {A, B, C} at time t communicate with the ground user terminal UE j The distances between the satellite and the Earth are: {800km, 660km, 900km};

[0139] Satellite service time range: [Ts min ,Ts max ] = [5min, 15min];

[0140] Satellite nodes {A, B, C} at time t communicate with the ground user terminal UE j The available service times are: {8min, 10min, 12min};

[0141] The set of adjacent satellites of satellite A is: {A, M, B, I, Q};

[0142] The set of adjacent satellites of satellite B is: {B, A, C, E, F};

[0143] The set of adjacent satellites of satellite C is: {C, B, N, G, H};

[0144] Step 1: First, the ground user terminal generates a service utility function f based on the service indicators and their corresponding satellite-to-ground distance, satellite service time, and satellite load utilization parameters. j =α j f 1j +β j f 2j +γ j f 3j , where α j ,β j ,γ j These are the weighting coefficients for the parameters of satellite-to-ground distance, satellite service time, and satellite payload utilization, respectively. 1j ,f 2j ,f 3jThe numerical values ​​of the business utility function parameters are represented separately, and the weight coefficients of the business utility function are generated using the analytic hierarchy process (AHP).

[0145] Step 1a: List the importance of service utility function parameters under different ground user terminal service types. The importance of service utility function parameters can be divided into five levels: extremely high, high, medium, average, and low.

[0146] Table 1 Importance of Business Characteristics

[0147]

[0148] Step 1b: Use the analytic hierarchy process (AHP) to analyze the importance of satellite-to-ground distance, satellite service availability, and satellite load utilization for different services. First, define importance scales for different indicators, mapping the three types of service indicator parameters to different importance levels from 1 to 9.

[0149] Table 2. Indicator Importance Scale

[0150] Scale Meaning of scale difference 1 This indicates that the two indicators are equally important. 3 This indicates that one of the two indicators is slightly more important than the other. 5 This indicates that one of the two indicators is more important than the other. 7 This indicates that one indicator is significantly more important than the other. 9 This indicates that one of the two indicators is far more important than the other. 2,4,6,8 The median of the two adjacent judgments above reciprocal If the scale of index A is 3 compared to index B, then the scale of B compared to A is 1 / 3.

[0151] Step 1c: Based on the indicator importance scales given in Steps 1a and 1b, calculate the importance of the utility function parameters for different types of services, including voice services, streaming media services, interactive services, and back-end services.

[0152] Table 3 Importance of Voice Service Indicator Parameters

[0153] Voice services / metrics Earth-space distance Satellite service time Load utilization Earth-space distance 1 3 5 Satellite service time 1 / 3 1 3 Load utilization 1 / 5 1 / 3 1

[0154] Table 4 Importance of Streaming Media Service Metrics

[0155]

[0156]

[0157] Table 5 Importance of Interactive Business Metrics Parameters

[0158] Interactive business / metrics Earth-space distance Satellite service time Load utilization Earth-space distance 1 1 / 3 1 / 3 Satellite service time 3 1 1 Load utilization 3 1 1

[0159] Table 6 Importance of Back-End Business Metrics Parameters

[0160] Back-end business / metrics Earth-space distance Satellite service time Load utilization Earth-space distance 1 1 / 3 1 / 6 Service hours 3 1 1 / 3 Load utilization 6 3 1

[0161] Step 1d: Calculate the weight coefficients for different business functions using the Analytic Hierarchy Process (AHP). First, obtain the normalized weight of each column for each indicator, and then calculate the average value of each indicator row by row to obtain the utility function weight coefficients α for different business functions. j ,β j ,γ j .

[0162] Table 7 Weights of Various Indicators for Different Businesses

[0163] Earth-space distance Service hours Load utilization Voice services 0.6334 0.2605 0.1061 Streaming media services 0.1022 0.6865 0.2113 Interactive business 0.1428 0.4286 0.4286 Backend business 0.0960 0.2510 0.6530

[0164] Table 7 provides the weighting parameters for different services regarding satellite-to-ground distance, satellite service availability, and satellite load utilization:

[0165] Business 1 weight parameter α j =0.6334,β j =0.2605,γ j =0.1061;

[0166] Business 2 weight parameter α j =0.1022,β j =0.6865,γ j =0.2113;

[0167] Business 3 weight parameter α j =0.1428,β j =0.4286,γ j =0.4286;

[0168] Business 4 weight parameter α j =0.0960,β j =0.2510,γ j =0.6530.

[0169] Step 2, LEO satellite i Calculate the current local load utilization parameter based on the local physical channel resource block load.

[0170] Load utilization threshold ρ h =0.9;

[0171] Load utilization of satellite nodes {A, B, C, E, F, M, N, G, H, I, Q} The values ​​are {0.35, 0.55, 0.7, 0.3, 0.4, 0.55, 0.2, 0.15, 0.1, 0.7, 0.8}.

[0172] Step 3, LEO satellite i Collect data on the load utilization of its adjacent satellites and calculate the variance of satellite load utilization Var within this set. Lin (t), and the satellite load utilization variance threshold

[0173] The number of satellites in the adjacent satellite set is 5, ρ h / 2 = 0.45. Assuming the satellite load utilization rate in the adjacent satellite set is {0,0,0,0.45,0.45} under extreme conditions, the satellite load utilization variance threshold can be calculated using Formula 2.

[0174] Variance of load utilization of adjacent satellite set of satellite A (Var) LAn (t) = 0.02865;

[0175] Variance of load utilization of adjacent satellite set of satellite B (Var) LBn (t) = 0.02648;

[0176] Variance Var of the load utilization of adjacent satellite sets of satellite C LCn (t) = 0.07175.

[0177] Step 4, Ground User Terminal (UE) j Receive broadcast signals from the satellite side to obtain the currently visible set of satellites.

[0178] Step 5: The ground user terminal determines whether the currently accessible satellites meet the service requirements based on the satellite-side feedback parameters, and sets the satellite load adjustment factor l. i Based on the satellite load utilization feedback from the satellite side, adjust parameter l i Numerical value.

[0179] Step 5a, Visible Satellite Set China's satellite available payload utilization If the current business load requirements can be met, proceed to step 5c.

[0180] Step 5c, Visible Satellite Set No update is needed. According to formula 2 in step 3, the variance of load utilization Var in this satellite ensemble is... Lik (t) = 0.02992. Given that the satellite load utilization rate in the visible satellite set under extreme conditions is {0, 0, 0.45}, the variance threshold of the satellite load utilization rate can be calculated using Formula 2.

[0181] Note: The variance of the satellite load utilization rate is 0.0675 when the satellite load utilization rate is set to {0,0,0.45} or {0,0.45,0.45}.

[0182] Step 5d: Determine the set of visible satellites Load utilization variance Var Lik (t) and variance threshold Size, Var Lik (t) = 0.02992 is less than

[0183] Determine the variance Var of the load utilization of the adjacent satellite sets of satellites A, B, and C respectively. LAn (t), Var LBn (t), Var LCn (t) and variance threshold The size of Var LAn (t) = 0.02865, Var LBn (t) = 0.02648, all less than Var LCn (t) = 0.07175 greater than Proceed to step 5e, and adjust the load adjustment factor parameters based on the load utilization of the set of adjacent satellites of satellite C.

[0184] Step 5e: The satellite's load adjustment factor needs to be adjusted. i If satellite C's neighboring satellite set contains both satellite B and satellite C, which are both visible to the terminal, the load adjustment factors for satellite B and satellite C can be adjusted.

[0185] Satellite B l i The adjustment factor is:

[0186] Satellite C l i The adjustment factor is:

[0187] Step 6: Normalize the satellite-to-ground distance, satellite service time, and satellite load utilization rate indicators, and then apply the utility function weighting coefficient α. j ,β j ,γ j Calculate the utility function values ​​of satellites within the visible satellite set.

[0188] Step 6a: Based on the range of satellite-to-ground distance [D] min D max And the current distance D between the terminal and the satellite ij Calculate the utility function value f 1j Satellite A: f 1j ={0.6334*0.6667, 0.1022*0.6667, 0.1428*0.6667, 0.0960*0.6667}; Satellite B: f 1j ={0.6334*0.9, 0.1022*0.9, 0.1428*0.9, 0.0960*0.9}; Satellite C: f 1j={0.6334*0.5, 0.1022*0.5, 0.1428*0.5, 0.0960*0.5}.

[0189] Step 6b: Based on the satellite's available service time range [Ts] min ,Ts max And the current terminal and satellite service availability time Ts i,j Calculate the utility function value f 2j Satellite A: f 2j ={0.2605*0.3, 0.6865*0.3, 0.4286*0.3, 0.2510*0.3}; Satellite B: f 2j ={0.2605*0.5, 0.6865*0.5, 0.4286*0.5, 0.2510*0.5}; Satellite C: f 2j ={0.2605*0.7, 0.6865*0.7, 0.4286*0.7, 0.2510*0.7}.

[0190] Step 6c: Based on the current satellite load utilization parameters Calculate the utility function value f 3j Satellite A: f 3j ={0.1061*0.65, 0.2113*0.65, 0.4286*0.65, 0.6530*0.65}; Satellite B: f 3j ={0.1061*0.45, 0.2113*0.45, 0.4286*0.45, 0.6530*0.45}; Satellite C: f 3j ={0.1061*0.3, 0.2113*0.3, 0.4286*0.3, 0.6530*0.3}.

[0191] The utility function values ​​f for satellites A, B, and C corresponding to different services j =α j f 1j +β j f 2j +γ j f 3j They are respectively:

[0192] Satellite A: f j ={0.5694, 0.4114, 0.5023, 0.5637}

[0193] Satellite B: f j ={0.7481, 0.5303, 0.5357, 0.5057}

[0194] Satellite C:f j={0.5468, 0.5950, 0.5000, 0.4196}

[0195] Step 7: Based on the satellite objective function F j =α j f 1j +β j f 2j +γ j f 3j ·l j Calculate the target values ​​of accessible satellites for different services.

[0196] Service 1: Satellite AF j =0.5694, Satellite BF j =0.7361, satellite CF j =0.5152;

[0197] Service 2: Satellite AF j =0.4114, Satellite BF j =0.5065, satellite CF j =0.5598;

[0198] Service 3: Satellite AF j =0.5023, Satellite BF j =0.4875, satellite CF j =0.4283;

[0199] Service 4: Satellite AF j =0.5637, Satellite BF j =0.4322, satellite CF j =0.3107.

[0200] Therefore, terminal service 1 can choose to access satellite B, service 2 can choose to access satellite C, and services 3 and 4 can choose to access satellite A.

[0201] Step 8, LEO satellite i After receiving the service request message and successfully connecting, update the load utilization parameters of satellite A. The variance of the load utilization of its adjacent satellite set, Var Lin (t) = 0.0291; Load utilization parameter of satellite B The variance of the load utilization of its adjacent satellite set, Var Lin (t) = 0.0273; Load utilization parameter of satellite C The variance of the load utilization of its adjacent satellite set, Var Lin (t) = 0.0727.

[0202] As can be seen, Service 3 is optimally connected to Satellite B based on the utility function value calculated in Step 6, and optimally connected to Satellite A after load balancing adjustment in Step 7. At the same time, the variance of the load utilization of the satellite set {A, B, C, E, F, M, N, G, H, I, Q} decreases from 0.057827 to 0.057823, indicating that the variance of the load utilization of the satellite network within a certain range is reduced while the service is connected.

[0203] In summary, the load-balanced dynamic access method under multi-satellite coverage of the present invention considers both the service's requirements for satellite parameters and the satellite network's load balancing requirements. Based on service QoS requirements and dynamic network load balancing requirements, this access method constructs a terminal service access objective function based on weight coefficients and load adjustment factors, according to the importance of satellite parameters corresponding to the user-side terminal's service QoS requirements and satellite load usage. It simultaneously considers user terminal service requirements and satellite network load balancing characteristics, solving the access decision problem for both the user side and the satellite side when accessing services via satellite. The satellite load adjustment method constructs two satellite sets on the satellite side: a visible satellite set and a neighboring satellite set. It determines whether the currently accessible satellites meet the service requirements and adjusts the load balancing parameters of the two types of satellite sets to adjust the satellite load adjustment factor and the target value of the accessible satellites. This invention satisfies the multi-objective requirements of different types of services from ground user terminals while considering the actual capabilities of the satellite network, enabling local dynamic load balancing of the satellite network corresponding to the current user terminal within a certain time and range. It can be applied to low-orbit satellite network service access such as China Star Network, demonstrating both inventiveness and practicality.

[0204] The parts of this invention not described in detail are common knowledge to those skilled in the art.

[0205] Although the present invention has been described in detail above with general descriptions and specific embodiments, modifications or improvements can be made to it, which will be obvious to those skilled in the art. Therefore, all such modifications or improvements made without departing from the spirit of the present invention are within the scope of protection of the present invention.

Claims

1. A dynamic access method for load balancing under multi-satellite coverage, characterized in that, include: On the user side, user terminal services are classified according to QoS requirements, multi-objective utility functions are generated based on service indicators, and multi-objective weight coefficients are generated for the importance of different services. On the satellite side, a set of satellites visible to the terminal and a set of adjacent satellites for each satellite are constructed. Load balancing parameters and load adjustment methods for the set of satellites visible to the terminal and the set of adjacent satellites for each satellite are proposed so that the satellite network corresponding to the current user terminal can achieve dynamic load balancing within a certain period of time. Specifically, the steps include the following: Step 1, Ground User Terminal A service utility function is generated based on the service indicators and their corresponding satellite-to-ground distance, satellite service time, and satellite load utilization parameters. The subscript j indicates the label of different ground user terminals, specifically: ； in, These are the weighting coefficients for the parameters of satellite-to-ground distance, satellite service time, and satellite payload utilization. Characterizing the utility function of satellite-to-ground distance, A function characterizing the service time utility of a satellite. A utility function characterizing satellite load balancing; Step 2, Satellite Calculate the current local load utilization rate based on the local physical channel resource block load. The subscript 'i' indicates different satellite designations, and the calculation method is as follows; ； in, Characterizing different satellite services, Characterizing the current time in the satellite Next Number of resource blocks used by each service Represents the current satellite time The sum of the number of resource blocks used by all services. This indicates the number of services that the satellite is currently accessing at time t. This represents the total number of resource blocks currently available to the satellite; To characterize the satellite load utilization threshold, if the satellite If the current load utilization rate is greater than or higher than this threshold, the satellite cannot access any new services; otherwise, it can. Step 3: Define the satellite At any moment The set of adjacent satellites, , For satellite The number of adjacent satellites, For set The number of satellites in the middle, , ; The variance of satellite load utilization is used to characterize the dispersion of satellite load utilization. (Satellite ensemble) Satellite payload utilization variance The average of the squares of the differences between each value in the set and the mean is calculated. The calculation formula is as follows: ； in For set The number of satellites in the middle, The average load utilization of all satellites in the satellite ensemble; satellite ensemble Satellite load utilization variance threshold The variance threshold of satellite load utilization in the satellite set calculated at time t is used as a threshold to measure the satellite load balance. Step 4, User Terminal Receive satellite broadcast signals to obtain time Visible satellite collection Defined as , For set The number of satellites in the middle, ; Step 5: The ground user terminal determines whether the currently accessible satellites meet the service requirements based on the feedback parameters from the satellite side, and sets the satellite load adjustment factor. Adjust parameters based on satellite load utilization data reported from the satellite side. Numerical value; Step 6: Normalize the satellite-to-ground distance, satellite service time, and satellite load utilization rate indicators, and then apply the utility function weighting coefficients. Calculate the utility function values ​​of satellites within the visible satellite set; Step 7: Define the ground user terminal Satellite access The satellite objective function is Based on the satellite load adjustment factor obtained in step 5 and the satellite utility function value obtained in step 6 Calculate the target value of accessible satellites; select the satellite corresponding to the maximum target value as the optimal access satellite; Step 8, Satellite After receiving the service request message and successfully accessing the network, update the local physical channel resource block load status and the load utilization parameter. and the variance of load utilization of adjacent satellite sets information.

2. The load balancing dynamic access method under multi-satellite coverage according to claim 1, characterized in that, Step 1 specifically includes: Step 1a: List the importance of service utility function parameters under different ground user terminal service types. The importance of service utility function parameters can be divided into five levels: extremely high, high, medium, average, and low. Step 1b: Use the analytic hierarchy process (AHP) to analyze the importance of satellite-to-ground distance, satellite service time, and satellite load utilization for different services; define different importance scales for the three types of service indicators and map them to different importance scales from 1 to 9. Step 1c: Based on the indicator importance scales given in Steps 1a and 1b, calculate the importance of the utility function parameters for voice services, streaming media services, interactive services, and back-end services, respectively. Step 1d: Calculate the weight coefficients for different business functions using the Analytic Hierarchy Process (AHP). First, obtain the normalized weight of each column for each indicator, and then calculate the average value of each indicator row by row to obtain the utility function weight coefficients for different business functions. .

3. The load balancing dynamic access method under multi-satellite coverage according to claim 1 or 2, characterized in that, Satellite load utilization variance threshold The settings include: Set satellite load utilization The range is [0, ], Given the pre-set satellite load utilization threshold, the number of load utilization values ​​in the set is: Given the number and range of values ​​in the set, the maximum value of the variance in load utilization. The corresponding set of values ​​contains only the maximum value. The dispersion is highest when the minimum value is 0; when the maximum numerical difference in the set is less than When the difference in the largest data value in the set is greater than or equal to a certain value, it indicates that the load balancing is relatively good. When the load balance is low, it indicates that the load balancing is weak and needs adjustment; define the load utilization set value range as [0, ...]. The satellite load utilization value is taken only at its maximum value. The variance calculated from the minimum value of 0 is the maximum variance of the set. This serves as a threshold for measuring satellite load balancing.

4. The load balancing dynamic access method under multi-satellite coverage according to claim 1 or 2, characterized in that, Step 6 specifically includes: Step 6a: The ground user terminal obtains the range of low-Earth orbit satellite distances based on prior knowledge. and the current distance between the user terminal and the satellite ,in ,but ; Calculate the set of satellites that can be accessed for the service separately. Function values ​​of the satellite ; Step 6b: The ground user terminal obtains the satellite's service time range based on prior knowledge such as ephemeris. and the current terminal and satellite service time ,in ,but ; Calculate the set of satellites that can be accessed for the service respectively Function values ​​of the satellite ; Step 6c: The ground user terminal receives the current load utilization parameters fed back by the satellite. ,calculate ; Calculate the set of satellites that can be accessed for the service respectively Function values ​​of the satellite .

5. The load balancing dynamic access method under multi-satellite coverage according to claim 1 or 2, characterized in that, Step 5 specifically includes: Step 5a: First, the user terminal determines the currently accessible satellite set. Based on the load situation, determine the available load utilization rate of satellites in this set in turn. Does it meet the current business load requirements? If yes, proceed to step 5c; otherwise, proceed to step 5b. Step 5b, in the satellite assembly If the satellite is deleted, proceed to step 5c. If the updated satellite set... If it is an empty set, proceed to step 5g; Step 5c, Updated Satellite Set Calculate the updated satellite set Load utilization variance And based on the method for calculating the variance threshold of satellite load utilization, calculate Satellite load utilization variance threshold ;in, and Refer to step 3 and The calculation method; Step 5d: Determine the variance of load utilization. Is it greater than or equal to the load utilization variance threshold? If the value is greater than or equal to the threshold, proceed to step 5e; Receive updated satellite set The set of adjacent satellites for each satellite Load utilization variance Determine whether it matches the load utilization variance threshold calculated in step 4. If the value is greater than or equal to the threshold, proceed to step 5e; If the variance of resource utilization of both satellite sets is less than the corresponding threshold value, proceed to step 5f; Step 5e: The satellite's load adjustment factor needs to be adjusted. ; The default value is 1, and the numerical range is defined as [0,2]. The range of satellite load utilization can be divided into... and Comparison of satellite sets Utilization of each satellite and Size; like This indicates that the satellite's load is too low, and the satellite's load adjustment factor needs to be increased. Increase the target value for satellite access. The adjustment factor is: ; like This indicates that the satellite has a large load and the load adjustment factor needs to be reduced. Reduce the target value for satellite access. The adjustment factor is: ; Step 5f: No adjustment to the satellite's load adjustment factor is required. ; Step 5g: No suitable satellites are available. Please wait for the next time period to select again.

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