Method to prevent a large number of attachment processes from preempting data services in NTN scenarios

Abstract

The present invention relates to the field of communication technology, and discloses a method for preventing a large number of attachment processes from preempting data services in an NTN scenario, including setting an upper threshold value N1 and a lower threshold value N2 of the number of random access sessions; counting the number of random access sessions Caps currently in progress; when the number of Caps reaches the threshold value N1, strict control is implemented on the random access process; when the number of Caps is lower than or equal to the threshold value N2, the strict control of the random access process is released. Through dynamic management of the number of Caps, threshold value regulation and strict access control strategy, precise resource allocation and adaptability in high-load scenarios are achieved, and the data transmission quality of users already on the network is prioritized. Combined with the 80ms timing template and resource utilization optimization, the scheduling efficiency of signaling and data services is improved. Compared with the existing technology, it solves the problems of resource allocation solidification, excessive signaling occupation and high data transmission delay, and significantly enhances the stability and flexibility of the system.

Description

Technical Field

[0001] The present invention relates to the field of communication technology, and in particular to a method for preventing a large number of attachment processes from preempting data services in an NTN scenario. Background Art

[0002] With the development of NTN (non-terrestrial network) technology, especially in NB-IoT and NR systems, the pressure of random access and attachment processes on resource allocation has become increasingly prominent. Satellite cells have a wide coverage area and a large number of terminals, but the priority scheduling strategy in existing technologies often places random access signaling above data services, resulting in attachment signaling occupying a large amount of cell resources in high-load scenarios, hindering the normal service scheduling of users on the network. Especially in LEO satellite mobile scenarios, a large number of terminals frequently initiate attachment processes due to dynamic changes in cell coverage, further exacerbating the problem of resource exhaustion.

[0003] The current fixed threshold control strategy is difficult to adapt to dynamic load changes. When the load is low, resources are underutilized; when the load is high, the threshold value is too high, which leads to excessive signaling overhead. In addition, the scheduling of signaling and data resources lacks real-time coordination, resulting in fixed resource allocation and inability to flexibly adjust according to the load. Under multi-cell or multi-orbit satellite coverage, the problems of load imbalance and resource waste between cells have not been effectively solved.

[0004] The attachment process consumes a lot of uplink and downlink resources, but the existing technology fails to dynamically allocate resources for different stages of the process, and the resource recovery mechanism after the attachment fails is also imperfect, further reducing the efficiency of cell resource utilization. These deficiencies lead to resource waste and reduced data service quality, especially in high-density access scenarios. Therefore, a technical solution for dynamic access management and resource scheduling optimization is urgently needed to address the limitations of existing technologies. Summary of the invention

[0005] In view of the deficiencies in the prior art, the present invention provides a method for preventing a large number of attachment processes from preempting data services in an NTN scenario, thereby solving the problem that cell resources are excessively occupied due to random access and attachment processes of users in the NTN scenario, resulting in interruption of data services for users on the network and low resource utilization efficiency.

[0006] To achieve the above objectives, the present invention is implemented through the following technical solutions: A method for preventing a large number of attachment processes from preempting data services in an NTN scenario, comprising: S1. setting an upper threshold value N1 and a lower threshold value N2 of the number of random access sessions;

[0007] S2. Count the number of random access sessions Caps currently in progress;

[0008] When the number of Caps reaches the threshold value N1, the random access process is strictly controlled;

[0009] When the number of Caps is less than or equal to the threshold value N2, the strict control of the random access process is released;

[0010] Dynamic maintenance of the number of Caps includes:

[0011] When the terminal initiates an attach request, the number of Caps increases by 1;

[0012] When the terminal attachment process is successfully completed, the number of Caps decreases by 1;

[0013] When the terminal attachment process fails and is released, the number of Caps decreases by 1.

[0014] Preferably, the maintenance of the number of Caps also includes the following steps:

[0015] Determine whether the terminal random access completion message carries an attach request;

[0016] If an attach request exists, release the terminal and reduce the number of Caps by 1.

[0017] Preferably, strict control of the random access process includes one of the following strategies:

[0018] Strategy 1: Do not respond to any contention random access request;

[0019] Strategy 2: Respond to the contention random access request, but directly release the terminal carrying the attachment request.

[0020] Preferably, the method is applicable to NTNNB-IoT and NTNNR scenarios, and is particularly applicable to low-orbit satellite scenarios based on NB-IoT.

[0021] A system to prevent a large number of attachment processes from preempting data services in NTN scenarios, including:

[0022] A counting module for counting the number of Caps;

[0023] A determination module for determining whether the number of Caps reaches a threshold value;

[0024] A scheduling module for performing random access control, wherein the scheduling module implements strict control or cancels strict control on the random access process based on threshold values ​​N1 and N2;

[0025] The system controls the occupation of cell resources by the terminal's attachment process by dynamically maintaining the number of Caps.

[0026] Preferably, the counting module is implemented by real-time monitoring of the terminal's attachment request message, attachment completion message, and attachment failure release message;

[0027] The determination module generates corresponding scheduling instructions based on preset threshold values ​​N1 and N2.

[0028] Preferably, the scheduling module supports configuration as strategy one or strategy two;

[0029] Strategy 1 is used to block all contention random access;

[0030] Strategy 2 releases the terminal carrying the attach request by identifying the attach request in the random access completion message.

[0031] A NTN cell resource management method allocates channel resources by controlling the number of Caps in the cell, the method comprising:

[0032] Periodically optimize the channel allocation of the random access process according to the 80ms timing template;

[0033] The number of CAPS supported per second does not exceed 4, ensuring the data service quality for online users.

[0034] Preferably, by adjusting the priority relationship between data and control signaling, data uplink and downlink services of users already on the network are preferentially guaranteed.

[0035] Preferably, the threshold values ​​N1 and N2 are dynamically adjusted according to the real-time load of the cell, the number of users and the satellite coverage;

[0036] Adjustment methods include remote configuration through the OAM system.

[0037] The present invention provides a method for preventing a large number of attachment processes from preempting data services in an NTN scenario. It has the following beneficial effects:

[0038] 1. The present invention adopts a technical solution based on dynamic management of the number of Caps and threshold value regulation, and achieves the technical effect of accurate allocation of cell resources under high load conditions by controlling the strictness of random access in real time. Compared with the single fixed threshold control method in the prior art, it solves the problem of inflexible resource allocation and excessive preemption of cell resources by random access signaling.

[0039] 2. The present invention achieves the technical effect of giving priority to data transmission and service continuity of users already on the network by introducing two strict control strategies (completely rejecting contention access or conditionally releasing attached users). Compared with the scheduling method in the prior art where the signaling priority is higher than the data priority, the present invention solves the problem of insufficient resource occupation of data services by signaling in the attachment process.

[0040] 3. The present invention adopts a technical solution of dynamically adjusting threshold values ​​and periodically optimizing resource allocation, which can adaptively adjust the access control strategy according to the cell load and historical data, and achieves the technical effect of adapting to high-load and multi-user environments. Compared with the method of statically configuring threshold values ​​in the prior art, it solves the problem of resource scheduling being rigid and unable to adapt to dynamic changes in user load.

[0041] 4. The present invention optimizes the scheduling ratio of uplink and downlink resources through the technical solution of combining the 80ms timing template with the dynamic calculation of resource utilization, and achieves the technical effect of efficiently allocating resources between signaling and data services. Compared with the problem of lack of targeted resource allocation strategy in the prior art, it solves the problems of large resource overhead of attachment process and high data transmission delay. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 It is a schematic diagram of the steps of the present invention;

[0043] Figure 2 It is a schematic diagram of the network access process of the present invention;

[0044] Figure 3 Schematic diagram of uplink and downlink scheduling timing template designed for 80ms period in the present invention;

[0045] Figure 4 It is a schematic diagram of the uplink timing in the present invention;

[0046] Figure 5 Schematic diagram of the downlink timing in the present invention Figure 1 ;

[0047] Figure 6 Schematic diagram of the downlink timing in the present invention Figure 2 ;

[0048] Figure 7 Schematic table 1 of NPDSCH TBS in the present invention;

[0049] Figure 8 Table 2 is a schematic diagram of NPDSCH TBS in the present invention. DETAILED DESCRIPTION

[0050] The following will be combined with the drawings in the specification of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0051] The present invention relates to a method for preventing a large number of attachment processes from preempting data services in an NTN scenario, which is applicable to NB-IoT and NR communication systems of non-terrestrial networks (NTN), especially low-orbit satellite (LEO) coverage areas. The following describes the implementation of the present invention through detailed steps, fully discloses its technical content, and enables those skilled in the art to reproduce the present invention.

[0052] The number of Caps (access sessions) is the core indicator of random access control, and its maintenance is directly related to the dynamic allocation of cell resources and the scheduling efficiency of user access. Therefore, it is necessary to first define the initial state of Caps, and dynamically count and adjust the number of Caps during the access process. In general, the statistics and initialization of Caps are the basis of attachment process management, and must be able to reflect the random access load status in the current system in real time. Specifically, this step requires defining the initialization conditions for Caps and establishing dynamic update rules to ensure that it is synchronized with the access status in real time.

[0053] In the implementation of this step, the number of Caps statistics needs to be able to reflect the following change scenarios: new user attachment request, new user attachment completion, and attachment failure or user release. By responding to and counting these events, it is ensured that the number of Caps can accurately reflect the random access load of the current cell. At the same time, this step also needs to be effectively connected with the random access control mechanism and resource scheduling module to provide accurate statistical basis for the execution of subsequent steps.

[0054] The specific implementation of initialization and statistics of the number of Caps is as follows:

[0055] Caps initialization:

[0056] Generally, when the system is started or the cell is restarted, the number of Caps needs to be initialized. As an option, the initial value of Caps can be set to 0 to ensure that there is no random access load pressure in the initial state.

[0057] Specifically, when the cell is initialized, the system calls the Caps management module and sets the current Caps count value to 0. At this time, the system is in an idle state with no user attachment request, and all cell resources are available for allocation.

[0058] In some embodiments, the initial value of Caps can also be dynamically set according to the historical load of the cell or configuration parameters. For example:

[0059] If the historical load shows that the cell access is frequent, the initial value of Caps can be set to a negative value less than 0, indicating that the system can accept more initial access requests.

[0060] If cell resources are limited, the initial value of Caps can be set to a small positive number to trigger the access control mechanism in advance.

[0061] Dynamic statistics of the number of Caps:

[0062] The dynamic change rules of the number of caps are the core content of this step. Generally, the number of caps is adjusted in real time according to the following events during the terminal access process:

[0063] When the system receives an attachment request, the number of Caps increases by 1;

[0064] When the terminal's attachment process is completed, the number of Caps decreases by 1;

[0065] When the attach process fails or the terminal is released, the number of caps decreases by 1.

[0066] Specifically:

[0067] For the logic of increasing the number of Caps for an attachment request, the system will trigger the counting module through the signaling process after receiving the attachment request message and increase the Caps value by 1.

[0068] Regarding the logic of reducing the number of Caps upon attach completion, when the attach process is successfully completed and the PDN connection is established, the system triggers a Caps update and reduces its value by 1.

[0069] For the processing of attachment failure or terminal release, the system monitors events such as signaling timeout and abnormal terminal exit, and reduces the Caps value after confirming the release process.

[0070] Special judgment for attachment request:

[0071] As a possible implementation, in order to distinguish the attachment process from the activation request of the user who is already online, the system in this embodiment can introduce the detection logic of the attachment request flag. Specifically:

[0072] When the system detects that the random access completion message (such as MSG5) carries an attach request, the system will immediately release the terminal and reduce the Caps value by 1.

[0073] In some special scenarios, the determination of the attachment request flag can be combined with the NAS layer message (such as AttachRequest) in the signaling to perform multi-layer verification to ensure the accuracy of the counting.

[0074] Mathematical model and formula description:

[0075] To further ensure the accuracy of Caps statistics, the present invention introduces a mathematical description formula for the change in the number of Caps:

[0076] Caps t =Caps t-1 +N attach\_req -N attach\_comp -N attach\_fail

[0077] in:

[0078] Caps t Indicates the number of Caps at the current moment;

[0079] Caps t-1 Indicates the number of Caps at the last moment;

[0080] N attach\_req Indicates the number of attachment requests received at the current moment;

[0081] N attach\_comp Indicates the number of terminals that have completed the attachment process at the current moment;

[0082] N attach\fail Indicates the number of terminals that have failed to attach or have been released at the current moment.

[0083] In a possible implementation, the system may calculate the number of Caps in real time based on the above formula, and trigger a random access control strategy through dynamic threshold comparison (see subsequent steps).

[0084] Considerations for multiple Caps management scenarios:

[0085] As an extension, in some multi-scenario networks, the statistics of the number of Caps may need to be maintained separately for different types of attachment requests. For example:

[0086] Independent Caps counts are maintained for NB-IoT and NR users respectively, so that differentiated control strategies can be set for users of different access types.

[0087] The number of Caps is counted for high-priority users (such as emergency service users) and ordinary users respectively to ensure that the attachment requests of emergency service users are not restricted.

[0088] Through the above implementation steps, this embodiment can accurately count and dynamically maintain the number of Caps, providing basic data support for random access control and resource scheduling. The execution result of this step will be used as the input of the random access control threshold determination in the subsequent steps, directly affecting the execution effect of the access strategy.

[0089] After completing the initialization and dynamic statistics of the number of Caps, the system needs to set the threshold values ​​N1 and N2 based on the current cell's load capacity and historical data characteristics. In general, the threshold value is the core parameter of the random access control mechanism, which is used to trigger different access strategies. The choice of threshold value directly determines the access management effect of the system under high load and low load conditions, and provides access basis for strict control of random access. As an option, the threshold value can be dynamically adjusted according to the scheduling capacity of the cell resources to adapt to the user access needs of different scenarios.

[0090] Specifically, the present invention sets two threshold values: N1 is the upper threshold value, which is used to determine whether to trigger strict control; N2 is the lower threshold value, which is used to determine whether to cancel control. The threshold value setting process needs to comprehensively consider multi-dimensional factors such as the total amount of available resources in the cell, the current number of Caps, and the historical user access frequency. By dynamically adjusting the threshold value, flexible adaptation to different load scenarios can be achieved.

[0091] The specific implementation of threshold value setting and dynamic maintenance is as follows:

[0092] Setting of initial threshold value:

[0093] The thresholds N1 and N2 can be preset based on the resource capacity of the cell. For example, for the NB-IoT scenario, the maximum number of Caps supported per second by the cell is 4. In general, N1 can be set to 3, indicating that when the number of Caps reaches 3, the access control mechanism will enter a strict state. N2 can be set to 1, indicating that when the number of Caps drops to 1, the system releases strict control.

[0094] In some embodiments, the initial values ​​of N1 and N2 may be appropriately adjusted according to the resource allocation strategy of the cell. For example:

[0095] When the cell mainly carries low-latency services, N1 can be reduced to 2 to prioritize data services for online users.

[0096] In scenarios with large coverage but low user density, N1 can be increased to 4 to allow more users to access simultaneously.

[0097] Dynamic threshold adjustment mechanism:

[0098] As an option, the threshold value adjustment in the present invention can be dynamically optimized according to the real-time load of the cell and historical statistical data. Specifically, the system can dynamically calculate N1 and N2 by the following formula:

[0099] N1 t =α·R t +β·H t

[0100] N2t =γ·R t +δ

[0101] in:

[0102] N1 t Indicates the upper threshold value at the current moment;

[0103] N2 t Indicates the lower threshold value at the current moment;

[0104] R t Indicates the real-time resource utilization of the current cell, with a value range of 0 to 1;

[0105] H t Indicates the historical access frequency in times / second;

[0106] α, β, γ, and δ are weight factors, which are configured according to specific scenarios.

[0107] In a possible implementation, when the real-time load of the cell is high (such as R t >0.8), the system can increase the α value and improve N1, thereby reducing the frequency of access restrictions.

[0108] Dynamic update rules for threshold values:

[0109] In general, the system will periodically calculate and update the values ​​of N1 and N2. As an option, the update period can be set to seconds (such as 1 second) or dynamically adjusted (such as triggered in real time according to load fluctuations). The update process includes the following steps:

[0110] Monitor the current number of Caps and resource utilization;

[0111] Recalculate N1 and N2 according to the formula;

[0112] The updated threshold value is stored in the threshold value management module, and the random access control module is notified.

[0113] Threshold settings for multi-scenario adaptation:

[0114] To meet the needs of different scenarios, the threshold value can also be set in combination with multi-dimensional factors such as user priority and access type. For example:

[0115] For high-priority users (such as emergency service users), a lower N1 value can be set separately to give priority to the attachment requests of such users.

[0116] For mixed scenarios of NB-IoT and NR, the system can set two independent threshold values ​​to ensure fairness between the two access types.

[0117] Feedback mechanism for threshold adjustment:

[0118] In order to further optimize the accuracy of threshold setting, a feedback mechanism is introduced in the present invention. Specifically, the system will evaluate the rationality of the threshold based on historical data. For example:

[0119] If the number of Caps is found to be close to N1 for a long time, N1 can be appropriately increased to avoid triggering access control too early;

[0120] If the value is close to N2 for a long time, N2 can be reduced to speed up access recovery.

[0121] Through the above implementation, this embodiment can realize flexible setting and dynamic adjustment of the threshold value. The optimization of the threshold value ensures the accuracy of access control and provides a clear basis for the execution of the random access strategy. The execution result of this step will directly affect the triggering timing and flexibility of the access control mechanism, and is a key link in random access management.

[0122] After completing the dynamic statistics of the number of Caps and the setting of the threshold value, the system enters the stage of random access control. The main task of this step is to dynamically trigger the corresponding access control strategy based on the real-time number of Caps and the threshold value status. In general, the random access control strategy determines how the cell allocates resources when the load is high or low, so as to maximize the quality of data services and connections for existing users. Specifically, when the number of Caps reaches the threshold value N1, the system will enter the strict access control state; when the number of Caps is less than or equal to the threshold value N2, the control state will be released or adjusted. The random access control strategy not only needs to allocate resources reasonably, but also needs to ensure the identification and management of access users to avoid invalid access processes wasting system resources.

[0123] The specific implementation of the random access control strategy is as follows:

[0124] Triggering conditions for control strategies

[0125] Generally, the triggering condition of the random access control strategy is determined by the number of Caps and the threshold value. Specifically:

[0126] When the real-time Caps number Caps t Meet Caps t When ≥N1, the system enters the strict access control state.

[0127] When the real-time Caps number Caps t When ≤N2, the system removes the access restriction and resumes the normal access process.

[0128] In a possible implementation, the system compares the number of Caps with the threshold value in real time each time a new attachment request or completion event is received, and triggers a corresponding control strategy according to the comparison result.

[0129] How to implement strict access control

[0130] The strict access control strategy is the core mechanism of the system under high load conditions. Its goal is to limit the access of new users, thereby releasing more resources for the service transmission of existing users. As an option, the present invention provides the following two strict control strategies:

[0131] Strategy 1: Completely reject contention random access

[0132] In a possible implementation, the system shields all signals from contention random access.

[0133] In some embodiments, this strategy is mainly used in scenarios where cell resources are extremely tight, for example, the number of Caps is close to the theoretical limit of cell resources.

[0134] Strategy 2: Conditional response and release of the attachment request user

[0135] In another possible implementation, the system allows random access contention signals to enter, but performs an attachment request detection on the accessing user.

[0136] Specifically, when the system detects that the attach completion message (eg, MSG5) carries an attach request, the system will immediately release the user to reduce signaling consumption of the attach process.

[0137] For users who are already online and do not carry an attachment request (for example, users who have activated services), the system will respond to their access requests normally.

[0138] In some embodiments, the use of strategies can be adjusted in combination with historical data, such as enabling strategy 2 preferentially to reduce signaling overhead, or switching to strategy 1 under extremely high load.

[0139] Scheduling logic of access control policy

[0140] In a possible implementation, the scheduling logic of access control can be described by the following formula:

[0141]

[0142] in:

[0143] P allow Indicates the probability of whether access is allowed;

[0144] f(C, M) is a conditional judgment function used to detect the attachment request flag (C) and the remaining amount of cell resources (M).

[0145] As an option, the implementation of f(C, M) can adopt the following logic:

[0146] If C = 1 (indicates user attachment request), release immediately and set P allow =0.

[0147] If C = 0 and M > 0.2 (the remaining resource ratio is higher than 20%), then set P allow =1.

[0148] Timer-assisted mechanism for control strategies

[0149] In order to avoid too frequent policy switching, this embodiment introduces a timer mechanism to smooth the execution process of the control logic. Specifically:

[0150] When the system enters the strict control state, the T1 timer will be started to limit the minimum duration of access control.

[0151] When the system detects that the number of Caps is lower than N2, it will start the T2 timer to delay the removal of access restrictions and ensure the stability of system resources.

[0152] In some embodiments, the specific durations of T1 and T2 may be dynamically adjusted based on the historical load fluctuation characteristics of the cell. For example:

[0153] For cells with severe load fluctuations, the T1 duration can be shortened to quickly respond to access pressure.

[0154] For cells with stable loads, the T2 duration can be extended to avoid frequent access state switching.

[0155] Fine-grained control over the attachment process

[0156] In a possible implementation, in order to further optimize the resource usage of the attach process, this embodiment controls the specific signaling interaction of the attach process. For example:

[0157] When the system detects that the system message request (eg, SIB1 or SIB2) in the attach process occupies too many downlink channel resources, the impact can be reduced by dynamically adjusting the channel scheduling priority.

[0158] For terminals that fail to attach, the system will first release the channel resources they occupy and trigger resource cleanup in subsequent processes.

[0159] Extended application in multi-cell scenarios

[0160] In some scenarios with multi-cell coverage, the random access control strategy can be further extended. For example:

[0161] To address the imbalanced access load among multiple cells, the threshold value of each cell can be dynamically adjusted through the Caps quantity sharing mechanism among neighboring cells, thereby achieving more efficient load balancing.

[0162] For multi-orbit satellite coverage scenarios, the access pressure can be predicted based on the satellite movement trajectory, and strict control strategies can be triggered in advance.

[0163] Through the implementation of the above random access control, this embodiment can flexibly switch access strategies under different load scenarios, effectively alleviating the pressure of the attachment process on the occupation of cell resources. At the same time, the strictly controlled conditional design ensures that the service quality of users on the network can still be guaranteed under high load conditions. The execution of this step will directly determine the final effect of cell access management and is the core link of the entire random access control process.

[0164] After the random access control strategy is implemented, the resource allocation of the cell becomes a key link. The reasonable allocation of cell resources needs to dynamically respond to the load of random access while ensuring that the service quality of users on the network is not affected. In general, cell resource scheduling needs to be accurately allocated based on the current number of Caps, channel occupancy, and data service requirements. In this step, the scheduling relationship between signaling and data services is optimized by analyzing the uplink and downlink scheduling timing templates and resource utilization efficiency. In addition, the allocation of cell resources needs to be able to adapt to different communication scenarios, especially in the low-orbit satellite (LEO) environment, where latency and channel stability will affect resource allocation.

[0165] The specific implementation of cell resource allocation and scheduling optimization is as follows:

[0166] Uplink and downlink resource allocation mechanism

[0167] In a possible implementation, the uplink and downlink resources of a cell are allocated according to a period of 80 ms. Specifically:

[0168] In each cycle, resource scheduling follows a fixed timing template. For example, in the NB-Iot system, each 80ms cycle includes 7 NPDSCH scheduling opportunities and 14 NPDSCH scheduling opportunities.

[0169] Downlink resources are preferentially allocated to broadcast messages (such as SIB1 and SIB2) and attachment signaling (such as AttachAccept), and the remaining resources are used for data services.

[0170] Uplink resources are mainly used for user feedback signaling (such as ACK / NACK) and random access messages (such as MSG1 and MSG3).

[0171] As an option, in scenarios where the attach process is frequent, the interference of signaling on data services can be reduced by dynamically adjusting the downlink resource priority. For example:

[0172] Lower the scheduling priority of non-emergency signaling and allocate more downlink subframes to data services.

[0173] For the release process of users who fail to attach, uplink resources are allocated preferentially to speed up the completion of release signaling.

[0174] Optimizing resource utilization

[0175] Generally, the utilization efficiency of cell resources is affected by the random access process. Frequent scheduling of attachment signaling will lead to the waste of some resources. To this end, this embodiment introduces a resource utilization calculation model:

[0176]

[0177] in:

[0178] U t Indicates the resource utilization at the current moment;

[0179] R i represents the actual resource allocation of the i-th scheduling;

[0180] R total Indicates the total amount of resources in the cycle.

[0181] Specifically, the system calculates U in real time t , and dynamically adjust resource scheduling strategies based on utilization. For example:

[0182] If U t <0.7, indicating that resource utilization is low, and the system can increase the scheduling ratio of random access signaling.

[0183] If U t >0.9, indicating that resource utilization is high and the system needs to limit the scheduling frequency of attachment signaling.

[0184] In a possible implementation, the utilization rate can be further optimized by grouping resources. For example, each 80ms period is divided into a signaling resource group and a data resource group, and each is scheduled independently. This can avoid excessive occupation of data resources by signaling.

[0185] Solution to multi-channel resource conflicts

[0186] Specifically, cell scheduling needs to handle resource conflicts between uplink and downlink channels. For example, in an 80ms period, the use priority of uplink NPUSCH may be higher than that of downlink NPUSCH. To this end, a conflict detection mechanism is introduced in this embodiment. As an option, the system will check the channel allocation before scheduling and resolve conflicts according to the following rules:

[0187] If the uplink channel resources are insufficient, the uplink resources of low-priority attached users are released first.

[0188] If there is a downlink channel resource conflict, non-critical signaling will be postponed to the next periodic scheduling.

[0189] In some embodiments, the system may also resolve resource conflicts by using channel multiplexing technology, for example, by scheduling the attach signaling to an idle time slot by using a time offset technology, thereby improving overall resource utilization.

[0190] Dynamic limitation of resource consumption by attaching process

[0191] As a possible implementation method, this embodiment further analyzes the overhead of the attach process on cell resources and dynamically allocates resources according to different stages. For example:

[0192] In the initial stage of the attach process (eg, SIB1, MSG1 transmission), the system may allocate fewer resources to reduce signaling overhead.

[0193] During the critical stages of the attachment process (such as AttachAccept and AttachComplete transmissions), the system will temporarily increase resource allocation to speed up signaling completion.

[0194] Specifically, the dynamic resource allocation of the attachment process can be described by the following formula:

[0195]

[0196] in:

[0197] R attach Indicates the total amount of resources allocated to the attached process;

[0198] ω represents the priority coefficient of the attach signaling;

[0199] N attach\_req Indicates the number of current attachment requests;

[0200] N total Indicates the total number of users in the cell.

[0201] In some embodiments, the system can dynamically adjust the value of ω to adapt to different load scenarios. For example:

[0202] In a high-load scenario, the value of ω is reduced to reduce the resource usage of attach signaling.

[0203] In low-load scenarios, increasing the value of ω allows more users to complete attachment.

[0204] Resource adaptation in multi-orbit satellite scenarios

[0205] In scenarios with multi-orbit satellite coverage, resource allocation needs to consider the satellite's movement trajectory and coverage range. Specifically:

[0206] For low-orbit satellites (LEO), because their coverage changes rapidly, the system needs to prioritize the allocation of resources to users who have completed attachment to reduce signaling delays.

[0207] For medium-orbit satellites (MEO), the system can reserve certain resources for users who are about to enter the coverage area through resource pre-allocation.

[0208] In some embodiments, the system can also dynamically adjust resource allocation in combination with the satellite trajectory prediction model, for example, predicting the peak user attachment period based on the satellite trajectory and enabling a strict access control strategy in advance.

[0209] Through the above implementation, this embodiment can dynamically adjust the cell resource allocation strategy under different load and coverage scenarios. This step is combined with the previous Caps statistics, threshold setting and access control strategy to ensure efficient use of system resources and smooth operation of random access.

[0210] Embodiment 1:

[0211] Please refer to the attached Figure 2 -Attached Figure 8 , a large number of terminals in the satellite coverage area initiate the attachment process, which will block the uplink and downlink service scheduling of users already on the network. The traditional scheduling priority is the control signaling priority such as RRC / NAS, which is higher than the data service priority. Taking NB-IoT as an example, calculate the number of users that NB-IoT can accommodate per second:

[0212] The wireless resource overhead for a single UE to access the network is shown in Table 1:

[0213] Table 1:

[0214] Resource Name Resource times Number of occupied subframes NPRACH 2 14 NPUSCHformat1 10 21 NPUSCHformat2 13 26 NPDCCH 23 23 NPDSCH 15 25

[0215] Please refer to the attached for detailed cost calculation process. Figure 2 :

[0216] Network access process Figure 2As shown, it includes some sub-process interactions: system message acquisition, RRC connection establishment, Authentication process, NAS security activation, EMS information interaction (EPSsessionmanagement, such as protocol configuration options, APN information, etc.), attachment process, PDN connection establishment process, EMM message process (EPSmobilitymanagement, notifying the terminal after the EMM context is established), etc. The air interface overhead occupied by each signaling is as shown in Table 2:

[0217] Table 2:

[0218]

[0219]

[0220]

[0221] The cell timing arrangement diagram can estimate the number of times each channel can be scheduled per unit time and the number of resources, and obtain the total number of available resources in the cell, as shown in Figure 3:

[0222] Table 3:

[0223] Resource Name 80ms resource times 80ms resource quantity, SF NPRACH 1 7 NPUSCHformat1 7 39 NPUSCHformat2 7 14 Uplink resource waste 20 Total uplink resources 80 NPDCCH 14 14 NPDSCH 7 38 Downlink resource waste 8 Synchronous Block 20 Total number of downlink resources 80

[0224] Please refer to the attached Figure 4 -Attached Figure 6 , uplink and downlink scheduling timing template: NPDCCH-->NPDSCH, n+5+k0 subframe;

[0225] NPDSCH-->NPUSCHtype2, n+k0+koffset subframe;

[0226] NPDCCH-->NPUSCHtype1, n+k0+1+kofset subframe;

[0227] Kofset takes the value 15;

[0228] Search space period T*G = 16ms; the common multiple of SFN10ms is 80ms, that is, the search space repeats at a period of 80ms. The uplink and downlink scheduling timing template is designed based on a period of 80ms as shown in the attached figure. Figure 3 shown.

[0229] 1) According to the above introduction, the single UE network access overhead is shown in Table 4. It can be seen that the downlink NPDSCH requires 15 schedulings, which is the most expensive. Therefore, Caps is estimated based on the downlink NPDSCH overhead.

[0230] Table 4:

[0231] Resource Name Resource times Number of occupied subframes NPRACH 2 14 NPUSCHformat1 10 21 NPUSCHformat2 13 26 NPDCCH 23 23 NPDSCH 15 25

[0232] 2) The number and quantity of 80ms cell resources are shown in Table 5. There are 7 NPDSCH scheduling opportunities in 80ms, and one network access requires 15 NPDSCH scheduling opportunities. Therefore, one network access requires 3 80ms cycles, that is, 240ms. The maximum number of network access resources supported per second is 1000ms / 240ms≈4. The theoretical limit is Caps4, 4 times per second, and 240 network accesses per minute.

[0233] Table 5:

[0234]

[0235]

[0236] 3) Since there are 21 downlink scheduling opportunities within 240ms, Caps4 uses 15 of them, leaving 6. Every 240ms, 2 downlink scheduling opportunities of SIB1 and SIB2 / 3 need to be deducted, leaving 4 downlink scheduling opportunities. There are 21 uplink scheduling opportunities, Caps4 uses 10 of them, leaving 11 scheduling opportunities.

[0237] Downlink capacity (SF5, MCS13): 4*1256 / 240=20.9kbps

[0238] Uplink capacity (SF5, MCS10): 11*872 / 240=39.9kbps

[0239] The cell common channel overhead is shown in Table 6 below.

[0240] Table 6:

[0241]

[0242] It can be seen that the maximum Caps capacity of a single cell of the NTNNB-IOT system is 4, which will occupy 71% of the system's downlink resources. Assuming that the actual ground Caps is 5, it will occupy 100% of the cell resources, resulting in the inability of online users to obtain services.

[0243] Embodiment 2:

[0244] For NTNNB-IOT system, the N1 threshold is 3 and the N2 threshold is 1;

[0245] When the number of users currently attached to the cell CapsN>=3, the random access strict control is performed; when CapsN<=1, the random access strict control is canceled.

[0246] Maintenance of CpasN:

[0247] Initialize CpasN=0;

[0248] When a new Attachrequest is received from a user, CpasN = CpasN + 1;

[0249] When a new user's Attachcomplete is received, CpasN = CpasN-1;

[0250] When the user's Attachrequest fails, the release process is initiated, and CpasN = CpasN-1;

[0251] The condition 2) can be replaced by using MSG5TBsize greater than the threshold;

[0252] The condition 3) can be replaced by the number of DLNAS after MSG5. For the NB-IOT system, the number of DLNAS is 5, and the DLNAS+timer method can be used.

[0253] There are two strategies for strict random access control, and you can choose one of them:

[0254] Strategy 1: Do not respond to all contention random access; since non-contention random access is a service requirement for users who have already joined the network, only do not respond to all contention random access

[0255] Strategy 2: Respond to contention random access. When it is found that the random access completes and carries an attachment request, the user is released. Since users who have already attached to the network will also use contention random access to activate the connection when they enter the idle state and need to transmit services, the activation process occupies a small signaling overhead, so these users can be allowed to initiate the activation process. Whether the random access completion message carries an attachment request can be used to identify whether it is an attached user or an activated user. Attached users are directly released, and activated users continue to be served.

[0256] The system for preventing a large number of attachment processes from preempting data services in an NTN scenario described below and the method for preventing a large number of attachment processes from preempting data services in an NTN scenario described above can refer to each other.

[0257] The system that prevents a large number of attachment processes from preempting data services in NTN scenarios includes:

[0258] A counting module for counting the number of Caps;

[0259] A determination module for determining whether the number of Caps reaches a threshold value;

[0260] A scheduling module for performing random access control, wherein the scheduling module implements strict control or cancels strict control on the random access process based on threshold values ​​N1 and N2;

[0261] The system controls the occupation of cell resources by the terminal's attachment process by dynamically maintaining the number of Caps.

[0262] The counting module is implemented by real-time monitoring of the terminal's attachment request message, attachment completion message, and attachment failure release message;

[0263] The determination module generates corresponding scheduling instructions based on preset threshold values ​​N1 and N2.

[0264] The scheduling module supports configuration as strategy 1 or strategy 2;

[0265] Strategy 1 is used to block all contention random access;

[0266] Strategy 2 releases the terminal carrying the attach request by identifying the attach request in the random access completion message.

[0267] The system of this embodiment can be used to execute the above method embodiments, and its principles and technical effects are similar, which will not be repeated here.

[0268] The present invention also provides a NTN cell resource management method, which is used to perform the above method when executed. Channel resources are allocated by controlling the number of Caps in the cell, and the method includes:

[0269] Periodically optimize the channel allocation of the random access process according to the 80ms timing template;

[0270] The number of CAPS supported per second does not exceed 4, ensuring the data service quality for online users.

[0271] By adjusting the priority relationship between data and control signaling, the uplink and downlink data services of users already on the network are given priority.

[0272] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A method for preventing a large number of attachment processes from preempting data services in an NTN scenario, characterized in that: include, S1. By setting the upper and lower thresholds N1 and N2 of the number of random access sessions; S2. Count the number of random access sessions Caps currently in progress; When the number of Caps reaches the threshold value N1, the random access process is strictly controlled; When the number of Caps is less than or equal to the threshold value N2, the strict control of the random access process is released; Dynamic maintenance of the number of Caps includes: When the terminal initiates an attach request, the number of Caps increases by 1; When the terminal attachment process is successfully completed, the number of Caps decreases by 1; When the terminal attachment process fails and is released, the number of Caps decreases by 1.

2. The method for preventing a large number of attachment processes from preempting data services in an NTN scenario according to claim 1, characterized in that: The maintenance of the number of Caps also includes the following steps: Determine whether the terminal random access completion message carries an attach request; If an attach request exists, release the terminal and reduce the number of Caps by 1.

3. The method for preventing a large number of attachment processes from preempting data services in an NTN scenario according to claim 1, characterized in that: Strict control of the random access process includes one of the following strategies: Strategy 1: Do not respond to any contention random access request; Strategy 2: Respond to the contention random access request, but directly release the terminal carrying the attachment request.

4. The method for preventing a large number of attachment processes from preempting data services in an NTN scenario according to claim 1, characterized in that: This method is applicable to NTNNB-IoT and NTNNR scenarios, especially to low-orbit satellite scenarios based on NB-IoT.

5. A system for preventing a large number of attachment processes from preempting data services in NTN scenarios, characterized in that: The method for preventing a large number of attachment processes from preempting data services in the NTN scenario according to any one of claims 1 to 4 comprises: A counting module for counting the number of Caps; A determination module for determining whether the number of Caps reaches a threshold value; A scheduling module for performing random access control, wherein the scheduling module implements strict control or cancels strict control on the random access process based on threshold values ​​N1 and N2; The system controls the occupation of cell resources by the terminal's attachment process by dynamically maintaining the number of Caps.

6. The system for preventing a large number of attachment processes from preempting data services in an NTN scenario according to claim 5, characterized in that: The counting module is implemented by real-time monitoring of the terminal's attachment request message, attachment completion message, and attachment failure release message; The determination module generates corresponding scheduling instructions based on preset threshold values ​​N1 and N2.

7. The system for preventing a large number of attachment processes from preempting data services in an NTN scenario according to claim 5, characterized in that: The scheduling module supports configuration as strategy 1 or strategy 2; Strategy 1 is used to block all contention random access; Strategy 2 releases the terminal carrying the attach request by identifying the attach request in the random access completion message.

8. A method for managing NTN cell resources, characterized in that: A system for preventing a large number of attachment processes from preempting data services in an NTN scenario according to any one of claims 5 to 7, allocating channel resources by controlling the number of Caps in a cell, the method comprising: Periodically optimize the channel allocation of the random access process according to the 80ms timing template; The number of CAPS supported per second does not exceed 4, ensuring the data service quality for online users.

9. A NTN cell resource management method according to claim 8, characterized in that: By adjusting the priority relationship between data and control signaling, the uplink and downlink data services of users already on the network are given priority.

10. The method or system according to any one of claims 1 to 8, characterized in that: The thresholds N1 and N2 are dynamically adjusted according to the real-time cell load, number of users, and satellite coverage; Adjustment methods include remote configuration through the OAM system.

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