Laser satellite network and its routing stability control method and controller

Abstract

The application provides a laser satellite network and a routing stability control method and controller thereof. The method comprises: acquiring current transmission rate levels and historical transmission rate levels of each laser inter-satellite link in the laser satellite network, wherein the transmission rate level is a limited number of discrete levels obtained by quantizing an instantaneous transmission rate; comparing the current transmission rate level with the historical transmission rate level to determine whether a link state changes; when the comparison result indicates that the link state changes, calculating a cost penalty according to a magnitude of the transmission rate level change, and resetting a stability count to an initial value; when the comparison result indicates that the link state does not change, incrementing the stability count, and calculating a cost reward according to the stability count; calculating a link cost according to a reference cost, the cost penalty and the cost reward; and selecting a data transmission path composed of one or more laser inter-satellite links from the plurality of laser inter-satellite links based on the link cost.

Description

Technical Field

[0001] This application mainly relates to the field of satellite communication technology, and in particular to a laser satellite network and its routing stability control method and controller. Background Technology

[0002] Low Earth Orbit (LEO) satellite constellations have developed rapidly in recent years. Mega-constellation projects such as Starlink and Kuiper aim to provide high-speed, low-latency broadband access services globally by deploying thousands or even tens of thousands of LEO satellites. Unlike traditional radio frequency (RF) inter-satellite links, LEO satellite constellations employ laser inter-satellite links (ISL) to achieve high-speed data transmission between satellites. Laser communication offers advantages such as narrow beamwidth, good directivity, high bandwidth, and strong anti-interference capabilities, supporting transmission rates of several gigabits per second or even higher, thus meeting the ever-growing demand for low-latency communication.

[0003] However, laser inter-satellite links also present significant challenges to routing stability. Due to the extremely small divergence angle of the laser beam, satellites are required to maintain extremely high pointing and tracking accuracy. Simultaneously, low Earth orbit satellites move relative to each other at speeds of several kilometers per second, especially in polar regions where the relative angular velocities change drastically. This extreme relative motion, combined with the precise pointing requirements of the laser link, inevitably leads to high-frequency physical layer fluctuations in the laser inter-satellite link, manifesting as dramatic fluctuations in the link transmission rate over a short period—a phenomenon known as "link oscillation."

[0004] In the aforementioned highly dynamic environment, achieving a balance between the stability and responsiveness of routing protocols has become a core technical challenge for laser satellite networks. To address changes in link state, existing solutions transplant link-state routing protocols widely used in terrestrial networks to satellite networks. These protocols periodically flood Link State Advertisements (LSAs) to provide each node with the global network topology, then calculate the shortest path based on real-time link metrics (such as bandwidth and latency). However, the inherent flaw of these protocols lies in their treatment of every physical layer fluctuation as a topology change. In the high-frequency fluctuation environment of laser inter-satellite links, this can trigger LSA signaling storms, leading to continuous routing oscillations. More seriously, these protocols can only distinguish between "changes" and "no changes," failing to differentiate between "minor fluctuations" and "severe fluctuations," and unable to provide differentiated rewards for "consistently stable" links, resulting in a lack of fine-grained perception of link stability in routing decisions.

[0005] Therefore, there is an urgent need for a routing stability control method that can simultaneously sense fluctuation amplitude, provide stable rewards, and has computational complexity suitable for spaceborne deployment. Summary of the Invention

[0006] The technical problem to be solved by this application is to provide a laser satellite network and its routing stability control method and controller, so as to solve the problems of frequent switching of routing protocols, large consumption of computing resources, and easy generation of routing black holes caused by high-frequency physical layer fluctuations of laser inter-satellite links in laser satellite networks.

[0007] To address the aforementioned technical problems, this application provides a routing stability control method for laser satellite networks, comprising: acquiring the current transmission rate level and historical transmission rate level of each laser inter-satellite link in the laser satellite network, wherein the transmission rate level is a finite number of discrete levels obtained by quantizing the instantaneous transmission rate; comparing the current transmission rate level with the historical transmission rate level to determine whether the link status has changed; when the comparison result indicates that the link status has changed, calculating a cost penalty based on the magnitude of the transmission rate level change and resetting the stability count to an initial value; when the comparison result indicates that the link status has not changed, incrementing the stability count and calculating a cost reward based on the stability count; calculating the link cost based on the baseline cost, the cost penalty, and the cost reward; and selecting a data transmission path composed of one or more laser inter-satellite links from multiple laser inter-satellite links based on the link cost.

[0008] Optionally, the transmission rate tiers include at least two discrete levels, each discrete level corresponding to a preset transmission rate range and a preset baseline cost.

[0009] Optionally, the link cost is calculated according to the following formula:

[0010] in, Let $\frac{1}{2}$ be the link cost of the laser inter-satellite link from node $i$ to node $j$. The current transmission rate level. This is the baseline cost corresponding to the current transmission rate tier. For the aforementioned cost penalty, The penalty coefficient is... The magnitude of the change in transmission rate level. For the aforementioned cost incentive, As the reward coefficient, For the stability count, It is a monotonically increasing function for stability counting.

[0011] Optionally, the monotonically increasing function is:

[0012] Here, log() is the logarithmic function.

[0013] Optionally, the method further includes: obtaining the congestion metric of the laser inter-satellite link; weighting the link cost and the congestion metric to obtain a comprehensive routing cost; and selecting the data transmission path based on the comprehensive routing cost.

[0014] Optionally, the comprehensive routing cost is calculated according to the following formula:

[0015] in, The overall routing cost of the laser inter-satellite link from node i to node j Let $\frac{1}{2}$ be the link cost of the laser inter-satellite link from node $i$ to node $j$. For random disturbance factors, This is a congestion metric for the laser inter-satellite link from node i to node j. As the first weighting coefficient, This is the second weighting coefficient.

[0016] Optionally, the congestion metric includes at least one of the following: queue length, cache occupancy, queuing delay, and link utilization.

[0017] Optionally, it further includes: dividing the link operation cycle into at least a high-frequency fluctuation zone and a stable zone based on the satellite's orbital position; in the high-frequency fluctuation zone, performing the acquisition and comparison steps of the current transmission rate level and the historical transmission rate level at a first frequency; and in the stable zone, performing the acquisition and comparison steps of the current transmission rate level and the historical transmission rate level at a second frequency lower than the first frequency.

[0018] To address the aforementioned technical problems, this application provides a routing controller for laser satellite networks, comprising: The data receiving and quantization module is used to obtain the current and historical transmission rate levels of each laser inter-satellite link in the laser satellite network. The transmission rate level is a finite number of discrete levels obtained by quantizing the instantaneous transmission rate. The status comparison module is used to compare the current transmission rate level with the historical transmission rate level to determine whether the link status has changed; Parameter update module: When the comparison result indicates that the link status has changed, it calculates the cost penalty based on the magnitude of the change in the transmission rate level and resets the stability count to the initial value; when the comparison result indicates that the link status has not changed, it increments the stability count and calculates the cost reward based on the stability count. The link cost calculation module is used to calculate the link cost based on the baseline cost, the cost penalty, and the cost reward. The path determination module is used to select a data transmission path consisting of one or more laser inter-satellite links from multiple laser inter-satellite links based on the link cost.

[0019] To address the aforementioned technical problems, this application provides a laser satellite network, comprising: a data plane composed of low Earth orbit satellites, wherein the low Earth orbit satellites are configured to acquire the instantaneous transmission rate of the laser inter-satellite link and report it to a control plane; and a control plane composed of medium Earth orbit satellites or geostationary orbit satellites, wherein the medium Earth orbit satellites or geostationary orbit satellites are equipped with routing controllers, and the routing controllers are used to execute the method described in this application.

[0020] Optionally, the low Earth orbit satellites in the data plane are connected to the medium Earth orbit satellites or geostationary orbit satellites in the control plane via microwave links.

[0021] Compared with the prior art, this application has the following advantages: This application's laser satellite network and its routing stability control method and controller eliminate the impact of minute rate fluctuations on routing decisions by "quantifying the instantaneous transmission rate into a finite number of discrete levels," avoiding frequent route switching triggered by high-frequency, low-amplitude jitter. Simultaneously, it simplifies subsequent calculations to integer operations, reducing the computational burden on the onboard processor. By "comparing the current level with historical levels to determine if the state has changed and calculating cost penalties based on the magnitude of the change," the routing protocol can distinguish between slight and severe fluctuations. The more severe the fluctuation, the greater the penalty, and the higher the priority of the link being bypassed in routing selection, thus effectively suppressing routing oscillations and preventing data packets from continuously being sent to unstable links, creating a routing black hole. By "increasing the stability count when the state remains unchanged and calculating cost rewards based on the count," continuously stable links receive cost reductions, with longer periods of stability resulting in greater rewards, guiding traffic to converge on stable links and further reducing end-to-end latency and packet loss rate. In summary, this application implements an asymmetric routing mechanism of "penalizing fluctuations and rewarding stability," balancing routing stability and responsiveness under conditions of limited onboard resources. Attached Figure Description

[0022] The accompanying drawings are included to provide a further understanding of this application. They are incorporated into and constitute a part of this application. The drawings illustrate embodiments of this application and, together with this specification, serve to explain the principles of this application.

[0023] Figure 1 This is an architectural diagram of a laser satellite network according to an embodiment of this application.

[0024] Figure 2This is a flowchart of a routing stability control method for laser satellite networks according to an embodiment of this application.

[0025] Figure 3 This is a schematic diagram of a routing controller for a laser satellite network according to an embodiment of this application. Detailed Implementation

[0026] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of this application.

[0027] Figure 1 This is an architectural diagram of a laser satellite network according to an embodiment of this application. Figure 1 As shown, the laser satellite network includes a data plane and a control plane.

[0028] The data plane consists of Low Earth Orbit (LEO) satellites. The number of LEO satellites can be determined based on the constellation size, such as 96, 256, or more, distributed across multiple orbital planes (e.g., 12 to 32 orbital planes). Each LEO satellite transmits data at high speed to its neighboring satellites via an Inter-Satellite Link (ISL) L1, and is also equipped with a microwave communication module for communication with the control plane via a microwave link L2.

[0029] The main functions of the LEO satellite include: collecting physical layer status information of the laser inter-satellite link, including instantaneous transmission rate, link connection status, queue length, etc.; reporting the collected raw status information to the control plane through microwave link L2; receiving routing rules issued by the control plane and forwarding data packets according to the routing rules.

[0030] The control plane consists of medium Earth Orbit (MEO) satellites or geostationary Earth Orbit (GEO) satellites. The control plane is equipped with a routing controller responsible for implementing the routing stability control method described in this application.

[0031] The main functions of the control plane include: receiving link status information reported by LEO satellites; processing the raw status information (such as quantization, comparison, and calculation); executing routing algorithms and generating routing tables; and distributing routing rules to LEO satellites via microwave link L2.

[0032] Communication between LEO satellites and MEO / GEO satellites is achieved through microwave links. Microwave links have advantages such as wide coverage, low directional requirements, and maturity and reliability, making them suitable as a medium for inter-layer communication.

[0033] Figure 2 This is a flowchart of a routing stability control method for laser satellite networks according to an embodiment of this application. Figure 2 As shown, the routing stability control method 200 for laser satellite networks includes: Step S21: Obtain the current transmission rate level and historical transmission rate level of each laser inter-satellite link in the laser satellite network, where the transmission rate level is a finite number of discrete levels obtained by quantizing the instantaneous transmission rate.

[0034] The instantaneous transmission rate of the laser inter-satellite link changes dynamically during operation. To avoid frequent route switching due to small fluctuations in the rate and to adapt to the limited computing resources on the satellite, this application quantizes the continuous instantaneous transmission rate into a finite number of discrete transmission rate increments.

[0035] Specifically, this is achieved by mapping continuous rate values ​​to a finite number of discrete increments. Optionally, the instantaneous transmission rate is quantized into four discrete increments: S(t)∈{1,2,3,4}.

[0036] Tier 1 corresponds to 0~128 Mbps, and the corresponding base cost = 100; Tier 2 corresponds to 128~256 Mbps, with a corresponding base cost. = 75; Tier 3 corresponds to 256~512 Mbps, with a corresponding base cost. = 50; Gear 4 corresponds to speeds greater than 1 Gbps, with a corresponding baseline cost. = 25.

[0037] The higher the transmission rate tier (i.e., the higher the transmission rate), the lower the base cost. This is because routing protocols typically tend to choose lower-cost paths, so the base cost is inversely proportional to the transmission rate, giving high-speed links a natural advantage in routing.

[0038] It should be noted that the specific values ​​for the number of tiers, rate ranges, and baseline costs mentioned above are merely examples. Those skilled in the art can select different discrete tier numbers and corresponding values ​​based on actual network configurations (such as laser performance, constellation size, and service requirements). For example, in scenarios with abundant bandwidth resources, eight or more tiers can be set; in scenarios with limited bandwidth resources, two or three tiers can be set. These variations do not depart from the scope of protection of this invention.

[0039] In each routing cycle, the control plane receives the instantaneous transmission rate reported by the LEO satellite, quantizes it into the current transmission rate level S(t), and stores the historical transmission rate level S(t-1) of the previous cycle.

[0040] Step S22: Compare the current transmission rate level with the historical transmission rate level to determine whether the link status has changed.

[0041] Obtain the current transmission rate level S(t) and historical transmission rate level S(t-1) of each laser inter-satellite link in the laser satellite network.

[0042] Step S23: When the comparison result indicates that the link status has changed, calculate the cost penalty based on the magnitude of the change in the transmission rate level and reset the stability count to the initial value; when the comparison result indicates that the link status has not changed, increment the stability count and calculate the cost reward based on the stability count.

[0043] Compare the current transmission rate level S(t) with the historical transmission rate level S(t-1) to determine whether the link status has changed.

[0044] If S(t) = S(t-1), it indicates that the link state has not changed, meaning the transmission rate level remains stable. In this case, let the magnitude of the change in the transmission rate level be... =0, and set the stability counter Increment by 1, that is Stability counter Used to quantize the number of consecutive cycles the link maintains the current transmission rate level, optionally, The initial value is 1. This indicates that the link is continuous. Maintaining the same transmission rate level for each cycle, the longer the stable duration, the better. The larger the value, the better.

[0045] If S(t) ≠ S(t-1), it indicates a change in the link state, meaning a switch in the transmission rate level has occurred. In this case, the magnitude of the change in the transmission rate level needs to be calculated. and the stability counter In this embodiment, the value is reset to its initial value. The initial value is 1. This indicates that the link has just undergone a state change, the previous stable accumulation has been interrupted, and accumulation needs to start again. The magnitude of the change in transmission rate tiers. This reflects the degree of drastic change in gear. For example, when shifting from gear 4 to gear 3, ΔS = 1, which is a slight fluctuation; when shifting directly from gear 4 to gear 1, ΔS = 3, which is a sharp fluctuation.

[0046] This update mechanism allows the stability counter to reflect the stability history of the link in real time: the longer the link has been stable, the better. The larger the value, the more likely the link has recently undergone changes. The value was reset to 1.

[0047] Step S24: Calculate the link cost based on the baseline cost, cost penalty, and cost reward.

[0048] The calculation methods for cost penalties and cost rewards are described in detail below.

[0049] Cost penalty: When the link state changes, a cost penalty is calculated based on the magnitude of the state change ΔS. This embodiment uses a linear penalty function:

[0050] in, This is the penalty coefficient, which takes a positive value. The magnitude of the penalty coefficient determines the sensitivity of the routing protocol to link fluctuations. The larger the value, the more severely the fluctuating link is penalized, and the easier it is to be bypassed during routing. The smaller the value, the less impact the fluctuation has on routing decisions. In one embodiment, =3.

[0051] because The cost penalty P is proportional to the magnitude of the change: slight fluctuations ( When P = 1, P = 3, resulting in drastic fluctuations. = 3) When P = 9. This design allows the routing protocol to distinguish between different levels of fluctuation and impose a heavier penalty on severe fluctuations.

[0052] Cost incentive: When the link state remains unchanged, based on the stability counter. Calculate the cost reward.

[0053]

[0054] in, This is the reward coefficient, and its value is a positive number. It is a monotonically increasing function for stability counting.

[0055] In one implementation, a logarithmic reward function is used:

[0056] Here, log() is the logarithmic function, which can be the natural logarithm or the logarithm to base 2. Both are equivalent in monotonicity, differing only in their scaling factor. The advantage of using the logarithmic function as the reward function is that: as... As the value increases, the rate of increase in reward R gradually slows down (i.e., diminishing marginal rewards). This allows the link to achieve rapid reward growth in the early stages of stability, but after a long period of stability, the reward increase from the additional stability time gradually decreases, avoiding over-rewarding "old links". This design aligns with engineering intuition; the transition from "unstable" to "stable" is more valuable than the transition from "stable" to "more stable".

[0057] In one embodiment, =2. It can be calculated that... When the reward increases from 1 to 2, it increases by approximately 0.82; while When the reward increases from 9 to 10, it increases by approximately 0.20. The effect of diminishing marginal returns is clearly visible.

[0058] Link cost is the basis for routing decisions, based on baseline cost. The formulas for calculating cost penalty P and cost reward R are as follows:

[0059] in, Let $\frac{1}{2}$ be the link cost of the laser inter-satellite link from node $i$ to node $j$. This is the current transmission rate setting. This is the baseline cost corresponding to the current transmission rate tier. As a cost penalty, The penalty coefficient is... The magnitude of the change in transmission rate level. As a cost incentive, As the reward coefficient, For stability counting, It is a monotonically increasing function for stability counting.

[0060] Preferably, the link cost is calculated according to the following formula: .

[0061] The following example illustrates the link cost calculation process: Assume that the current tier of a link is S(t) = 4 (corresponding to the baseline cost). =25), penalty coefficient =3, reward coefficient =2.

[0062] When the link is stable =5, ΔS=0, link cost C=21.42.

[0063] When the link experiences slight fluctuations, the gear shifts from 4 to 3, with ΔS=1. Reset to 1, link cost C = 28.

[0064] When the link experiences severe fluctuations, it drops from gear 4 to gear 1, ΔS=3. Reset to 1, link cost C=34.

[0065] As can be seen from the above examples, stable links have the lowest cost (21.42), links with slight fluctuations have a higher cost (28), and links with severe fluctuations have the highest cost (34). Therefore, the routing algorithm will prioritize stable links with the lowest cost, thereby effectively suppressing routing oscillations.

[0066] In one implementation, the method also includes: obtaining the congestion metric of the laser inter-satellite link; weighting the link cost and the congestion metric to obtain the comprehensive routing cost; and selecting the data transmission path based on the comprehensive routing cost.

[0067] This embodiment further introduces a congestion metric to balance link stability and network load. The congestion metric characterizes the load or congestion level of the link and can employ any one or more combinations of the following parameters: Queue length: The number of data packets to be sent at the link output port, reflecting the current degree of queue backlog; Cache utilization: The ratio of used buffer capacity to total buffer capacity, reflecting the degree of cache saturation; Queuing delay: The average waiting time for data packets in the queue, reflecting the impact of congestion on latency; Link utilization: The ratio of busy link time to total time, reflecting bandwidth usage.

[0068] In this embodiment, queue length is preferred. As a congestion metric, queue length is used because it directly reflects the instantaneous congestion state of the output port and is easy to measure.

[0069] The formula for calculating the overall routing cost is:

[0070] in, The overall routing cost of the laser inter-satellite link from node i to node j; Let $C$ be the link cost of the laser inter-satellite link from node $i$ to node $j$. This is a random perturbation factor used to prevent global synchronization oscillations caused by simultaneous updates from multiple paths. Its value can be a random number in the range of (0.9, 1.1). The congestion metric for the laser inter-satellite link from node i to node j (in this embodiment, it is the queue length). As the first weighting coefficient, The second weighting factor is used to balance the impact of link stability and congestion on routing decisions. By adjusting the weighting factor, network operators can weigh "path stability" and "load balancing" according to actual needs. For example, when network congestion is severe, the weighting factor can be increased. To increase the weight of congestion metrics; when network fluctuations are frequent, the weight can be increased. Weights to improve link stability.

[0071] In some embodiments, a dynamic adaptation mechanism based on orbital awareness is further introduced to reduce the computational overhead of the control plane and adapt to the spatiotemporal fluctuation characteristics of the laser inter-satellite link. Depending on the satellite's orbital position, the fluctuation characteristics of the laser inter-satellite link exhibit distinct spatiotemporal patterns: in polar regions, the relative motion of the satellites is intense, and the link state changes frequently; in equatorial regions, the relative motion of the satellites is gentle, and the link state is relatively stable. Based on this observation, this application divides the link operating cycle into at least two regions: High-frequency fluctuation zone: This corresponds to the polar switching region of the satellite. In this region, the link status is updated more frequently to quickly respond to link changes; the link status transition follows a uniform probability distribution, with each state having an equal probability of occurrence.

[0072] Stable region: Corresponds to the equatorial cruising area of ​​the satellite. In this region, the link state update frequency is low to reduce computational overhead; link state transitions follow a probability distribution biased towards medium-to-high transmission rate segments, meaning that medium-to-high bandwidth segments have a higher probability of occurring.

[0073] In its implementation, the control plane first acquires the satellite's current orbital position (e.g., through ephemeris calculation or GPS positioning) and determines whether the satellite is located in a high-frequency fluctuation region or a stable region. Then, it dynamically adjusts the execution frequency based on the region type: in the high-frequency fluctuation region, it performs the acquisition and comparison of the current and historical transmission rate levels at a first frequency (e.g., every one routing cycle); in the stable region, it performs the acquisition and comparison of the current and historical transmission rate levels at a second frequency lower than the first frequency (e.g., every 10 routing cycles). Through this orbit-aware dynamic adaptation, this application can significantly reduce the computational and signaling overhead of the control plane while ensuring routing responsiveness, making it particularly suitable for large-scale LEO constellation deployment scenarios.

[0074] Step S25: Select a data transmission path consisting of one or more laser inter-satellite links from multiple laser inter-satellite links based on link cost.

[0075] The following describes in detail a method for selecting a data transmission path based on link cost (or comprehensive routing cost). For data transmission requirements from source node s to destination node d, a data transmission path needs to be selected from many possible paths. This application uses the link cost of each link... Or combined routing cost Select a path.

[0076] Specifically, the satellite network is abstracted as a graph G = (V, E), where V is the set of satellite nodes and E is the set of laser inter-satellite links. Each link (i, j) ∈ E is assigned a weight, which is the calculated link cost. Or combined routing cost Then, a shortest path algorithm is run on the graph to calculate the minimum weight path from source node s to destination node d. In this embodiment, Dijkstra's algorithm can be used to calculate the shortest path. Dijkstra's algorithm is a classic algorithm in graph theory that can efficiently calculate the single-source shortest path. Those skilled in the art will understand that other shortest path algorithms (such as Bellman-Ford algorithm, Floyd-Warshall algorithm, etc.) can also be used to achieve the same function. The calculated shortest path is composed of one or more laser inter-satellite links, represented as: Path = {(s, v1), (v1, v2), …, (v k The total cost of this path is the sum of the costs of each link. The control plane converts the calculated path into routing rules and sends them to the LEO satellites in the data plane via microwave links. The LEO satellites forward data packets according to the routing rules.

[0077] This application implements a routing strategy of "prioritizing stable links and temporarily bypassing fluctuating links", which effectively suppresses routing oscillations caused by high-frequency fluctuations in laser inter-satellite links.

[0078] Figure 3 This is a schematic diagram of a routing controller for a laser satellite network according to an embodiment of this application. Figure 3 As shown, the routing controller 300 includes: The data receiving and quantization module 31 is used to receive the raw status information reported by LEO satellites, quantize the instantaneous transmission rate into discrete transmission rate levels, and obtain the current and historical transmission rate levels of each laser inter-satellite link in the laser satellite network.

[0079] The status comparison module 32 is used to compare the current transmission rate level with the historical transmission rate level.

[0080] The parameter update module 33 calculates cost penalties and cost rewards based on the comparison results and updates the stability counter. Specifically, when the comparison results indicate a change in the link status, it calculates a cost penalty based on the magnitude of the change in the transmission rate level and resets the stability counter to its initial value; when the comparison results indicate no change in the link status, it increments the stability counter and calculates a cost reward based on the stability counter.

[0081] The link cost calculation module 34 is used to calculate the link cost based on the baseline cost, cost penalty, and cost reward.

[0082] Optionally, based on baseline cost The formula for calculating the link cost is as follows: (The formula is missing from the provided text.)

[0083] in, Let $\frac{1}{2}$ be the link cost of the laser inter-satellite link from node $i$ to node $j$. This is the current transmission rate setting. This is the baseline cost corresponding to the current transmission rate tier. As a cost penalty, The penalty coefficient is... The magnitude of the change in transmission rate level. As a cost incentive, As the reward coefficient, For stability counting, It is a monotonically increasing function for stability counting.

[0084] Preferably, the link cost is calculated according to the following formula: .

[0085] The path determination module 35 is used to select a data transmission path based on link cost (or comprehensive routing cost).

[0086] Optionally, the formula for calculating the comprehensive routing cost is:

[0087] in, The overall routing cost of the laser inter-satellite link from node i to node j; Let $C$ be the link cost of the laser inter-satellite link from node $i$ to node $j$. This is a random perturbation factor used to prevent global synchronization oscillations caused by simultaneous updates from multiple paths. Its value can be a random number in the range of (0.9, 1.1). The congestion metric for the laser inter-satellite link from node i to node j (in this embodiment, it is the queue length). As the first weighting coefficient, This is the second weighting coefficient.

[0088] This application is based on the link cost of each link. Or combined routing cost Path selection is performed. Specifically, the satellite network is abstracted as a graph G = (V, E), where V is the set of satellite nodes and E is the set of laser inter-satellite links. Each link (i, j) ∈ E is assigned a weight, which is the calculated link cost. Or combined routing cost Then, a shortest path algorithm is run on the graph to calculate the minimum weighted path from the source node s to the destination node d. In this embodiment, Dijkstra's algorithm can be used to calculate the shortest path.

[0089] The above modules can be deployed in the routing controllers of MEO or GEO satellites, implemented through software, hardware, or a combination of both.

[0090] This application also provides a computer program product containing instructions. The computer program product may be a software or program product containing instructions capable of running on a device or stored on any available medium. When the computer program product runs on at least one device, it causes the at least one device to perform a routing stability control method.

[0091] This application also provides a computer-readable storage medium. The computer-readable storage medium can be any available medium that the device can store, or a data storage device such as a data center that includes one or more available media. The available medium can be a magnetic medium (e.g., floppy disk, hard disk, magnetic tape), an optical medium (e.g., DVD), or a semiconductor medium (e.g., solid-state drive). The computer-readable storage medium includes instructions that instruct the device to perform a routing stability control method.

[0092] The laser satellite network and its routing stability control method and controller disclosed in this application have the following technical advantages: Suppressing routing oscillations: Through an asymmetric mechanism of "penalizing fluctuations and rewarding stability," the routing protocol naturally tends to select historically stable links, effectively suppressing routing oscillations caused by high-frequency fluctuations in laser inter-satellite links.

[0093] Reduce end-to-end latency: By avoiding the accumulation of queuing delays caused by routing oscillations, end-to-end transmission latency is significantly reduced.

[0094] Reduce packet loss rate: By bypassing historically unstable links, routing black holes during control plane updates are avoided, keeping packet loss rate below a low threshold.

[0095] Low computational complexity: Only state comparisons and basic arithmetic operations (addition, subtraction, logarithms) are required, without the need for complex machine learning training or iterative optimization, making it suitable for limited onboard computing resources.

[0096] Orbit-aware adaptation: Dynamically adjusts the link monitoring frequency based on the satellite's orbital position, reducing computational and signaling overhead while ensuring routing responsiveness.

[0097] Flowcharts are used in this application to illustrate the operations performed by the system according to embodiments of this application. It should be understood that the preceding or following operations are not necessarily performed in exact order. Instead, various steps can be processed in reverse order or simultaneously. Furthermore, other operations may be added to these processes, or one or more steps may be removed from these processes.

[0098] Furthermore, it should be noted that the use of terms such as "first" and "second" to define components is merely for the purpose of distinguishing the corresponding components. Unless otherwise stated, these terms have no special meaning and therefore should not be construed as limiting the scope of protection of this application. In addition, although the terminology used in this application is selected from commonly known and used terms, some terms mentioned in this application's specification may have been chosen by the applicant according to his or her judgment, and their detailed meanings are explained in the relevant sections of this description. Moreover, this application should be understood not only through the actual terms used, but also through the meaning implied by each term.

[0099] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the protection scope of the technical solutions of the embodiments of the present invention.

[0100] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product embodied on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0101] Obviously, those skilled in the art can make various modifications and variations to this application without departing from the spirit and scope of this application. Therefore, if such modifications and variations fall within the scope of the claims of this application and their equivalents, this application also intends to include such modifications and variations.

Claims

1. A routing stability control method for laser satellite networks, characterized in that, include: Obtain the current and historical transmission rate levels of each laser inter-satellite link in the laser satellite network. The transmission rate level is a finite number of discrete levels obtained by quantizing the instantaneous transmission rate. The current transmission rate level is compared with the historical transmission rate level to determine whether the link status has changed; When the comparison results indicate a change in the link status, a cost penalty is calculated based on the magnitude of the change in the transmission rate tier, and the stability count is reset to its initial value. When the comparison result shows that the link state has not changed, the stability count is incremented, and the cost reward is calculated based on the stability count. Calculate the link cost based on the baseline cost, the cost penalty, and the cost reward; Based on the link cost, a data transmission path consisting of one or more laser inter-satellite links is selected from multiple laser inter-satellite links.

2. The method as described in claim 1, characterized in that, The transmission rate tiers include at least two discrete levels, each of which corresponds to a preset transmission rate range and a preset baseline cost.

3. The method as described in claim 1, characterized in that, The link cost is calculated using the following formula: in, Let $\frac{1}{2}$ be the link cost of the laser inter-satellite link from node $i$ to node $j$. The current transmission rate level. This is the baseline cost corresponding to the current transmission rate tier. For the aforementioned cost penalty, The penalty coefficient is... The magnitude of the change in transmission rate level. For the aforementioned cost incentive, As the reward coefficient, For the stability count, It is a monotonically increasing function for stability counting.

4. The method as described in claim 3, characterized in that, The monotonically increasing function is: Here, log() is the logarithmic function.

5. The method as described in claim 1, characterized in that, Also includes: Obtain the congestion metric of the laser inter-satellite link; The link cost and the congestion metric are weighted and combined to obtain the comprehensive routing cost; The data transmission path is selected based on the comprehensive routing cost.

6. The method as described in claim 5, characterized in that, The comprehensive routing cost is calculated according to the following formula: in, The overall routing cost of the laser inter-satellite link from node i to node j Let $\frac{1}{2}$ be the link cost of the laser inter-satellite link from node $i$ to node $j$. For random disturbance factors, This is a congestion metric for the laser inter-satellite link from node i to node j. As the first weighting coefficient, This is the second weighting coefficient.

7. The method as described in claim 5, characterized in that, The congestion metrics include at least one of the following: queue length, cache occupancy, queuing latency, and link utilization.

8. The method as described in claim 1, characterized in that, Also includes: Based on the satellite's orbital position, the link operation cycle is divided into at least a high-frequency fluctuation zone and a stable zone; Within the high-frequency fluctuation zone, the steps of acquiring and comparing the current transmission rate level and the historical transmission rate level are performed at a first frequency. Within the stable region, the steps of acquiring and comparing the current transmission rate level and the historical transmission rate level are performed at a second frequency lower than the first frequency.

9. A routing controller for laser satellite networks, characterized in that, include: The data receiving and quantization module is used to obtain the current and historical transmission rate levels of each laser inter-satellite link in the laser satellite network. The transmission rate level is a finite number of discrete levels obtained by quantizing the instantaneous transmission rate. The status comparison module is used to compare the current transmission rate level with the historical transmission rate level to determine whether the link status has changed; Parameter update module: When the comparison result indicates a change in the link status, it calculates the cost penalty based on the magnitude of the change in the transmission rate level and resets the stability count to the initial value. When the comparison result shows that the link status has not changed, the stability count is incremented, and the cost reward is calculated based on the stability count. The link cost calculation module is used to calculate the link cost based on the baseline cost, the cost penalty, and the cost reward. The path determination module is used to select a data transmission path consisting of one or more laser inter-satellite links from multiple laser inter-satellite links based on the link cost.

10. A laser satellite network, characterized in that, include: A data plane consisting of low Earth orbit satellites, which are configured to acquire the instantaneous transmission rate of the laser inter-satellite link and report it to the control plane; A control plane consisting of medium Earth orbit satellites or geostationary orbit satellites, wherein the medium Earth orbit satellites or geostationary orbit satellites are equipped with routing controllers, the routing controllers being used to execute the method of any one of claims 1 to 8.

11. The laser satellite network as described in claim 10, characterized in that, The low Earth orbit satellites in the data plane are connected to the medium Earth orbit satellites or geostationary orbit satellites in the control plane via microwave links.

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