A deterministic satellite network adaptive snapshot routing method

Abstract

A deterministic satellite network adaptive snapshot routing method comprises the following steps: calculating transmission time according to deterministic traffic accessed by a satellite network and satellite link conditions, performing time slice division to form snapshot time slots adaptive to the size of each deterministic traffic, obtaining satellite node relationships connected in each snapshot time slot, and establishing a snapshot graph model adaptive to the traffic; judging whether the wireless link transmission time and the link transmission time between nodes are within the time when the satellite node gate is open according to the gate opening time of each satellite node on the wired connected path in each snapshot time slot, the wireless link transmission time between connected satellite nodes, and the wireless link transmission time slot time of the accessed satellite node, and finding a satellite node set meeting the requirements in each snapshot time slot according to the judgment; and superimposing the satellite node set in each snapshot time slot to obtain a transmission path set, which is the deterministic satellite network adaptive snapshot routing.

Description

Technical Field

[0001] This invention relates to an adaptive snapshot routing method for deterministic satellite networks, belonging to the field of communication technology. Background Technology

[0002] Deterministic satellite networks can build robust transmission paths for different types of services in fields such as emergency communications, emergency rescue, navigation and positioning, remote sensing and telemetry, national defense and security, and smart cities, ensuring the deterministic reach of critical business data. However, due to the high-speed movement of satellites at different periods and the dynamic changes in network load over time, the satellite network topology and multidimensional network resources (such as link capacity and node storage) are time-varying, posing a significant challenge to the construction of end-to-end transmission routes for deterministic satellite networks.

[0003] Currently, snapshot routing is the most commonly used centralized routing method in satellite networks. Snapshot routing is based on the periodicity of the satellite network topology, dividing the constellation into N time periods, abstracting the topology within each time period into a static topology, and performing route calculations within this static topology for each time period. However, it faces the following problems when dealing with massive satellite networks and deterministic transmission of multiple types of services:

[0004] (1) With the increase in the number of satellites and the increase in the number of satellite layers, the operating cycle of the satellite constellation also increases significantly, which will lead to a surge in the number of satellite topology snapshots and waste of on-board storage resources.

[0005] (2) Since the snapshot time period is a fixed time slot, deterministic services with a large volume of traffic need to be transmitted across time slots, which causes uncertainty in the service transmission delay due to storage and waiting at satellite nodes.

[0006] (3) For deterministic satellite networks, each satellite node controls the transmission of deterministic services through a “gate switch” method. This requires optimal matching of the transmission time slots, snapshot time slots and gate switch times of deterministic services to avoid storage and interruption of deterministic services. Summary of the Invention

[0007] The technical problem to be solved by this invention is to overcome the shortcomings of the prior art and solve the deterministic transmission problem of mega-satellite networks and multiple types of services.

[0008] The objective of this invention is achieved through the following technical solutions:

[0009] An adaptive snapshot routing method for deterministic satellite networks includes:

[0010] Transmission time is calculated based on the deterministic traffic volume and satellite link conditions accessed by the satellite network. Time slots are then divided to form snapshot time slots that adapt to the size of each deterministic traffic volume. The relationships between connected satellite nodes within each snapshot time slot are obtained, and an adaptive traffic snapshot graph model is established.

[0011] Based on the gate opening and closing times of each satellite node on the wired connection path within each snapshot time slot, the wireless link transmission time between connected satellite nodes, and the wireless link transmission time slot of the access satellite node, it is determined whether the wireless link transmission time slot and the link transmission time between nodes are within the time of the satellite node's gate opening. Based on this, a set of satellite nodes that meet the requirements within each snapshot time slot is found. The sets of satellite nodes within each snapshot time slot are superimposed to obtain a set of transmission paths, which is the deterministic satellite network adaptive snapshot route.

[0012] Compared with the prior art, the present invention has the following advantages:

[0013] (1) This invention proposes a deterministic network adaptive snapshot map construction method based on service characteristics. The snapshot time slot is calculated according to the service volume and reserved bandwidth, and the snapshot time of different deterministic services is accurately divided. In this way, a satellite network snapshot map with adaptive service traffic characteristics is established, which ensures that the deterministic service can transmit the service data packet completely within the snapshot time slot and eliminates the time delay uncertainty caused by the service waiting in the satellite node storage.

[0014] (2) This invention proposes a deterministic service optimal time slot matching transmission method. By judging the time sequence relationship between different types of time slots in which the deterministic service is located, the optimal matching satellite node for wireless link transmission time slot, wired gated time slot and snapshot time slot is obtained, thus forming a satellite network deterministic routing method, realizing end-to-end accurate transmission of deterministic services under the condition of converged transmission of wireless link and wired link. Attached Figure Description

[0015] Figure 1 This is a deterministic satellite network topology diagram.

[0016] Figure 2 This is a diagram showing the deterministic satellite network connectivity within the first snapshot time slot.

[0017] Figure 3 This is a diagram showing the deterministic satellite network connectivity within the second snapshot time slot.

[0018] Figure 4 This is a diagram showing the deterministic satellite network connectivity within the third snapshot time slot.

[0019] Figure 5 This is a time series relationship diagram. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of the present invention clearer, the embodiments of the present invention will be described in further detail below with reference to the accompanying drawings.

[0021] This invention addresses the problems of existing technologies by proposing an adaptive snapshot routing method for deterministic satellite networks. First, it constructs a deterministic satellite network service adaptive snapshot graph model. Based on the deterministic service volume and satellite link conditions accessing the satellite network, transmission time is calculated. This time slot is then used to divide the network into snapshot time slots suitable for each type of deterministic service volume, and the relationships between connected satellite nodes within each snapshot time slot are obtained, establishing an adaptive service volume snapshot graph model. Second, it proposes an optimal time slot matching transmission method for deterministic services. First, three time slot times are obtained: the gate opening / closing time of each satellite node on the wired connection path within each snapshot time slot, the wireless link transmission time between connected satellite nodes, and the wireless link transmission time slot of the accessing satellite node. Second, it determines whether the wireless link transmission time slot and the link transmission time between nodes are within the time of the satellite node's gate opening, and uses this as a basis to find a set of satellite nodes that meet the requirements within each snapshot time slot. Finally, the sets of satellite nodes within each snapshot time slot are superimposed to obtain a transmission path set, which is the deterministic satellite network adaptive snapshot route.

[0022] An adaptive snapshot routing method for deterministic satellite networks includes:

[0023] When S1.N types of deterministic services access the satellite network, the parameters of the accessed services must be notified to the satellite network management center. These service parameters include the workload V. d (i), i = 1, 2, ..., N, where the service originates at satellite node S and is destined for satellite node D. Simultaneously, the satellite network management center knows the bandwidth C reserved by each satellite node for deterministic services. d ;

[0024] S2. Calculate the transmission time T for each deterministic service on the inter-satellite node link. s (i), transmission time T s (i) Specifically: T s (i)=V d (i) / C d i = 1, 2, ..., N, and T s (i) Divide the time slices to form snapshot time slots with adaptive deterministic service rates;

[0025] S3. Based on the satellite network topology, obtain the connectivity relationships of all satellite nodes within each snapshot time slot, and construct a deterministic service adaptive snapshot graph model; specifically:

[0026] S31. Starting from the first snapshot time slot, let P be the set of satellite nodes connected to the initial satellite node S. If the destination satellite node D∈P, and its connection time T SD (i)>T s (i) then proceed to the next snapshot time slot, until T SD (i)≤T s (i) Record the snapshot slot number as T at this time. SD (i), then the corresponding snapshot graph model is [snapshot slot 1→T] SD (i) Satellite connectivity nodes S→D], the deterministic service adaptive snapshot model is established; if the target satellite node Then proceed to step S32;

[0027] S32. Select satellite node j∈P, if its connectivity time T sj (i)>T s (i) then proceed to the next snapshot time slot, until T sj (i)≤T s (i) Record the snapshot time slot number as t at this time. sj (i), then the corresponding snapshot diagram is [snapshot slot 1→t] sj (i), satellite node S→j], and proceed to step S33;

[0028] S33. From snapshot slot t sj Starting from (i)+1, let P be the set of satellite nodes connected to satellite node j. Select satellite node k∈P, if its connection time T jk (i)>T s (i) then proceed to the next snapshot time slot, until T jk (i)≤T s (i) Record the snapshot time slot number as t at this time. jk (i), then the corresponding snapshot diagram is [snapshot slot t] sj (i)→t jk (i), satellite connected nodes j→k]; repeat step S33 until k=D, the deterministic satellite network adaptive snapshot graph model is established, the snapshot graph model is [snapshot slot 1→t] sj (i)→t jk (i), satellite connectivity nodes S→j,j→k).

[0029] S4. Based on the gate control mechanism adopted by deterministic satellite networks, the gate opening time is the transmission time period G during which each satellite node reserves bandwidth for deterministic services. t The satellite network control center deploys the gate opening times of all satellite nodes in the deterministic satellite network, thereby obtaining the gate opening time G of connected satellite nodes within each snapshot time slot.t-start (i), i = 1, 2, ..., N, and the gate closing time G t-end (i), i = 1, 2, ..., N;

[0030] S5. Within each snapshot time slot, the access satellite node obtains the transmission time of the deterministic service on the connected link, the transmission time slot of the deterministic service radio link, and the gate opening time within the connected satellite node. By determining the time series relationship between these three factors, the optimal time slot matching for the deterministic service is formed, ensuring that the deterministic service does not incur queuing delays at the satellite node. The specific judgment conditions are as follows:

[0031] S51. Let T be the start time of the radio link transmission time slot allocated to the satellite node for deterministic service access. d-start (i), i = 1, 2, ..., N, with a final time T. d-end (i), i = 1, 2, ..., N; Step S4: The door opening and closing times within the access satellite node are known to be G. t-start (i),i=1,2,…,N and G t-end (i), i = 1, 2, ..., N, then the following condition G must be satisfied. t-start (i)≤T d-start (i)≤T d-end (i)≤G t-end (i), i = 1, 2, ..., N;

[0032] S52. Step S4: Given that the gate opening and closing times within the connected next-hop satellite nodes are G... t-start (i)',i=1,2,…,N and G t-end (i)', i = 1, 2, ..., N, and the start time of the wireless link transmission time slot allocated to the satellite node is T. d-start (i)', i = 1, 2, ..., N, ending at time T. d-end (i)', i = 1, 2, ..., N; Step (2) Given that the transmission time of the deterministic service on the connected link is T s (i), i = 1, 2, ..., N, then the following condition must be satisfied:

[0033] G t-start (i)'≤T d-start (i)+T s (i)≤T d-end (i)+T s (i)≤G t-end (i)', i = 1, 2, ..., N

[0034] G t-start (i)'≤T d-start (i)'≤T d-end (i)'≤Gt-end (i)', i = 1, 2, ..., N.

[0035] S6. The aforementioned deterministic service access starts at satellite node S and ends at satellite node D; here, the set of satellite nodes traversed by the deterministic satellite network adaptive snapshot route is set to Q, and step S7 is performed.

[0036] S7. Based on the adaptive snapshot map model obtained in step S3, starting from the first snapshot time slot and the access start satellite node S, in each snapshot time slot, a judgment is made according to the optimal time slot matching method in step S5. If the conditions of steps S51 and S52 are met, the corresponding satellite node is recorded to form the corresponding satellite node set Q(t). If the destination satellite node D∈Q(t), then proceed to step S8; if the destination satellite node D∈Q(t), then proceed to step S8. Then return to step S7;

[0037] S8. Merge the Q(t) obtained in step S7, remove duplicate satellite nodes, and obtain the set of satellite nodes Q. The path traversed by the satellite nodes in this set is the deterministic satellite network adaptive snapshot route, and the routing process ends.

[0038] Example:

[0039] An adaptive snapshot routing method for deterministic satellite networks includes:

[0040] S1. This example illustrates a deterministic service access to a satellite network. The parameters of the accessed service are notified to the satellite network management center. These parameters include a task volume of two units, the initial access satellite node S, and the destination satellite node D. Simultaneously, the satellite network management center knows the bandwidth C reserved by each satellite node for deterministic services. d For 0.25 units of data;

[0041] S2. Calculate the transmission time T for each deterministic service on the inter-satellite node link. s That is, T s =V d / C d = 8 units of time, and in T s Divide the time slices to form snapshot time slots with adaptive deterministic service rates;

[0042] S3. Based on the deterministic satellite network topology, obtain the connectivity relationships of all satellite nodes within each snapshot time slot, and construct a deterministic service adaptive snapshot graph model;

[0043] This assumes that the deterministic satellite network topology contains 5 satellite nodes, such as Figure 1As shown, these are satellite nodes 1, 2, 3, 4, and 5, respectively. The initial access satellite node for the service is set to S=1, and the destination satellite node for the service is set to D=5.

[0044] S31. Starting from the first snapshot time slot, obtain the deterministic satellite network connectivity at this moment, as follows: Figure 2 As shown, the set of satellite nodes connected to the initial satellite node S is P = {2}, and the destination satellite node is... Then proceed to step S32;

[0045] S32. In this example, assuming that the connection time between all satellite nodes is equal to the snapshot time slot time, the corresponding snapshot diagram is [snapshot time slot 1, satellite connected nodes 1→2], and proceed to step S33;

[0046] S33. Starting from snapshot slot 2, obtain the deterministic satellite network connectivity at this moment as follows: Figure 3 As shown, the set of satellite nodes connected to satellite node 2 is P = {3, 4}, and its connection time T 23 =T s T 24 =T s If the snapshot slot number is recorded as 2 at this time, then the corresponding snapshot image is [snapshot slot 1→2, satellite connection node 2→3, 2→4];

[0047] Repeat step S33, starting from snapshot slot 2, to obtain the deterministic satellite network connectivity at this moment, as follows: Figure 4 As shown, the set of satellite nodes connected to satellite node 2 is P = {5}. At this time, the destination node D ∈ P, and the adaptive snapshot graph model of the deterministic satellite network is established. The snapshot graph model is [snapshot slot 1→2→3, satellite connected nodes 1→2, 2→3, 2→4, 3→5, 4→5].

[0048] S4. Based on the gate control mechanism adopted by deterministic satellite networks, the gate opening time is the transmission time period G during which each satellite node reserves bandwidth for deterministic services. t The satellite network control center deploys the gate opening times of all satellite nodes in the deterministic satellite network, thereby obtaining the gate opening time G of connected satellite nodes within each snapshot time slot. t-start and the moment the door closes G t-end In this example, assume G t-start and G t-end These coincide with the start and end times of the snapshot time slot, respectively.

[0049] S5. Within each snapshot time slot, the access satellite node obtains the transmission time of the deterministic service on the connected link, the transmission time slot of the deterministic service radio link, and the gate opening time within the connected satellite node. By determining the time series relationship between the three, the optimal time slot matching for the deterministic service is formed, so that the deterministic service does not incur queuing delay at the satellite node. Specifically:

[0050] S51. Let T be the start time of the radio link transmission time slot allocated to the satellite node for deterministic service access. d-start The end time is T d-end Step S4: The known door opening and closing times within the access satellite node are G. t-start and G t-end Then the following condition G must be met. t-start ≤T d-start ≤T d-end ≤G t-end ;

[0051] S52. Step S4: Given that the gate opening and closing times within the connected next-hop satellite nodes are G... t-start 'and G t-end ', and the start time of the wireless link transmission time slot allocated to the satellite node is T. d-start ', the end time is T d-end Step (2) Given that the transmission time of deterministic services on the connected link is T s Then the following condition must be met: G t-start '≤T d-start +T s ≤T d-end +T s ≤G t-end ', at the same time G t-start '≤T d-start '≤T d-end '≤G t-end '.

[0052] S7. Based on the adaptive snapshot model obtained in step S3, the gate opening time of each satellite node, and the allocated wireless link transmission time slots, a time series relationship diagram is formed, as follows: Figure 5 As shown.

[0053] Starting from the first snapshot time slot and the access start satellite node S (i.e., satellite node 1), in each snapshot time slot, the optimal time slot matching method in step S5 is used to make a judgment. If satellite node 2 in snapshot time slot 1 satisfies the conditions of steps S51 and S52, then the corresponding satellite node is recorded to form the corresponding satellite node set Q(1) = {2}. If satellite node 3 in snapshot time slot 2 satisfies the conditions of steps S51 and S52, then the corresponding satellite node is recorded to form the corresponding satellite node set Q(2) = {3}. This continues until the target satellite node (i.e., satellite node 5) D∈Q(3), then step S8 is performed.

[0054] S8. Merge the Q(t) = {Q(1), Q(2), Q(3)} obtained in step S7, remove duplicate satellite nodes, and obtain the set of satellite nodes Q = {1, 2, 3, 5}. The path traversed by the satellite nodes in this set is the adaptive snapshot route of the deterministic satellite network, and the routing process ends.

[0055] The contents not described in detail in this specification are common knowledge to those skilled in the art.

[0056] Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make possible changes and modifications to the technical solutions of the present invention by utilizing the methods and techniques disclosed above without departing from the spirit and scope of the present invention. Therefore, any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solutions of the present invention shall fall within the protection scope of the technical solutions of the present invention.

Claims

1. A deterministic satellite network adaptive snapshot routing method, characterized in that, include: Calculate the transmission time of each deterministic service on the inter-satellite node link based on the deterministic traffic volume accessed by the satellite network and the satellite link conditions. ,by Time slots are divided to form snapshot time slots with adaptive deterministic service rates, and the relationships between connected satellite nodes within each snapshot time slot are obtained to establish a snapshot graph model of adaptive service volume. Establishing an adaptive traffic snapshot model includes: S41. Starting from the first snapshot time slot, connect to the initial satellite node. The set of connected satellite nodes is If the target satellite node If its connectivity time Then proceed to the next snapshot time slot, until when At that time, record the snapshot time slot number as... The corresponding snapshot model is [snapshot slot]. Satellite connectivity node The deterministic business adaptive snapshot model has been established; if the target satellite node Then proceed to step S32; S42. Select satellite nodes If its connectivity time Then proceed to the next snapshot time slot, until when At that time, record the snapshot time slot number as... The corresponding snapshot image is [snapshot slot]. Satellite nodes ], and proceed to step S33; S43, from snapshot slot Initially, with satellite nodes The set of connected satellite nodes is Select satellite nodes If its connectivity time Then proceed to the next snapshot time slot, until when At that time, record the snapshot time slot number as... The corresponding snapshot image is [snapshot slot]. Satellite connectivity node Repeat step S33 until... The adaptive snapshot map model for deterministic satellite networks has been established. This snapshot map model consists of [snapshot slots]. Satellite connectivity node ]; Based on the gate opening and closing times of each satellite node on the wired connection path within each snapshot time slot, the wireless link transmission time between connected satellite nodes, and the wireless link transmission time slot of the access satellite node, it is determined whether the wireless link transmission time slot and the link transmission time between nodes are within the time of the satellite node's gate opening. Based on this, a set of satellite nodes that meet the requirements within each snapshot time slot is found. The sets of satellite nodes within each snapshot time slot are superimposed to obtain a set of transmission paths, which is the deterministic satellite network adaptive snapshot route.

2. The deterministic satellite network adaptive snapshot routing method according to claim 1, characterized in that, When a deterministic service accesses the satellite network, it needs to notify the satellite network management center of the parameters of the service to be accessed, and the service will initially access the satellite node. Business Purpose Satellite Node Meanwhile, the satellite network management center is aware of the bandwidth reserved by each satellite node for deterministic services. .

3. The deterministic satellite network adaptive snapshot routing method according to claim 1, characterized in that, Based on the gate control mechanism used in deterministic satellite networks, the gate opening time is the transmission period during which each satellite node reserves bandwidth for deterministic services. The satellite network control center deploys the gate opening times of all satellite nodes in the deterministic satellite network, thereby obtaining the gate opening and closing times of connected satellite nodes within each snapshot time slot.

4. The deterministic satellite network adaptive snapshot routing method according to claim 3, characterized in that, Within each snapshot time slot, the access satellite node obtains the transmission time of the deterministic service on the connected link, the transmission time slot of the deterministic service radio link, and the door opening time within the connected satellite node. By judging the time series relationship between the three, the optimal time slot matching for the deterministic service is formed, so that the deterministic service does not need to generate queuing delay at the satellite node.

5. The deterministic satellite network adaptive snapshot routing method according to claim 4, characterized in that, Let the start time of the radio link transmission time slot allocated to the satellite node for deterministic service access be . The end time is Based on the gate opening and closing times within the access satellite node, respectively and Then the following conditions must be met. .

6. The deterministic satellite network adaptive snapshot routing method according to claim 5, characterized in that, Based on the gate opening and closing times within the connected next-hop satellite nodes, respectively and And the start time of the wireless link transmission time slot allocated to the satellite node is The end time is And the transmission time of deterministic services on the connectivity link is Then the following conditions must be met: ， and .

7. The deterministic satellite network adaptive snapshot routing method according to claim 4, characterized in that, Based on the adaptive snapshot map model, starting from the first snapshot slot and the access start satellite node... Initially, in each snapshot time slot, a judgment is made based on the optimal time slot matching method. If the conditions are met, the corresponding satellite node is recorded, forming a corresponding satellite node set. If the target satellite node If so, then a merge operation will be performed.

8. The deterministic satellite network adaptive snapshot routing method according to claim 7, characterized in that, During the merge operation, duplicate satellite nodes are removed, resulting in a set of satellite nodes. .

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