CN115801093A - A path planning method to guarantee the end-to-end deterministic delay of satellite network - Google Patents

Abstract

A path planning method that guarantees the end-to-end deterministic delay of the satellite network. Firstly, the space-time map of the satellite network is constructed for the service characteristics, and the transmission time slot is calculated according to the task traffic and the capacity of the satellite link, and the role of the time slot on the task is calculated. The time domain is divided, and then the satellite network space-time diagram is established according to the connection relationship and connection duration of the satellite network nodes in the time slot; then, according to the time-varying characteristics of the satellite link, the task traffic size, the satellite node connection link capacity and the satellite node resource Allocation is a constraint condition, and the path planning calculation method is determined by the business transmission start and end time and link connection time; finally, the task access satellite node is used as the first hop starting point, and the path planning calculation method is used in all connected adjacent nodes. Find the next hop path node until the destination node, thereby obtaining the deterministic transmission path of the satellite network, thereby forming a satellite network path planning method with deterministic delay guarantee.

Description

A path planning method to guarantee the end-to-end deterministic delay of satellite network

technical field

The invention relates to a path planning method for ensuring end-to-end deterministic time delay of a satellite network, and belongs to the technical field of communication.

Background technique

Spatial information networks need to build robust transmission paths for different types of services in areas such as emergency communications, emergency rescue, navigation and positioning, remote sensing and telemetry, national defense security, and smart cities to ensure the deterministic accessibility of key business data. However, due to the high-speed movement of satellites in different periods and the dynamic change of network load over time, the spatial information network topology and multi-dimensional network resources (such as link capacity, node storage, etc.) are time-varying, resulting in end-to-end deterministic transmission paths. It is difficult to build, and it is difficult to guarantee the quality of service such as deterministic delay and delay jitter.

Existing satellite network routing algorithms (such as open shortest path routing, connected graph routing, etc.) are designed based on static graph theory, without considering the random characteristics of network services and resources themselves, which will cause service packets to be lost in satellite nodes. Inconsistent arrival times and unstable link status will also cause service packets to be stored and waited for, resulting in a long-tail effect of service end-to-end delay, resulting in delay uncertainty and affecting the "punctuality" of deterministic services. , accurate" transmission and the timeliness of business messages.

Contents of the invention

The technical problem to be solved by the present invention is to overcome the deficiencies of the prior art and solve the path planning problem under the condition of ensuring the end-to-end deterministic time delay of the satellite network.

The object of the invention is achieved through the following technical solutions:

A path planning method for ensuring end-to-end deterministic delay of a satellite network, comprising:

Calculate the transmission time slot according to the task traffic and satellite link capacity, and divide the task action time domain according to this time slot, and then establish the satellite network space-time diagram according to the connection relationship and connection duration of the satellite network nodes in the time slot;

Take the task access satellite node as the first hop starting point, find the next hop path node in all connected adjacent nodes according to the path planning method, until the destination node, thereby obtaining the deterministic transmission path of the satellite network, thus forming a deterministic Satellite network path planning method with permanent delay guarantee;

The path planning method is specifically: taking the size of the task traffic, the link capacity of the satellite node connection, and the resource allocation of the satellite node as the constraint conditions, and taking the start and end time of the service transmission and the link connection time as the judgment conditions to perform path planning.

Preferably, the basic unit time τ is calculated based on the greatest common divisor v _φ of all traffic volumes included in the task and the capacity parameter C(t) of the inter-satellite link; the basic unit time is used as time slots to divide the task action time domain.

Preferably, according to the space _- time diagram of the satellite network, the continuous connection time Δt _uv (t _i ,t _{i + m} ).

Preferably, the path planning method is specifically:

则该任务业务量传输时间Δt_sk(M)＝t_{sk_end}-t_{s_start}，在集合Q中选取与起始节点所连通的卫星节点，若Δt_sk(M)在卫星节点(s,k)连通时间的连续区间内，即Δt_sk(M)≤Δt_uv(t_i,t_i+m),u＝s,v＝k,t_{s_start}≥t_i,t_{sk_end}≤t_i+m，则将卫星节点k作为当前的寻路节点，并写入确定性路径节点集合P中，并将该节点从集合Q中删除；若Δt_sk(M)＞Δt_uv(t_i,t_i+m),u＝s,v＝k，即该任务业务量不能在卫星节点(s,k)连通时间的连续区间内完成传输，则卫星节点k不满足要求；If the starting node of the pathfinding is the task access satellite source node S, then the starting time is the task access time t _{s_start} , according to the link capacity C(s,k) between the starting node and the connected satellite node, calculate The transmission end time t _{sk_end} of the task traffic on the satellite link is calculated as:

Then the task traffic transmission time Δt _sk (M) = t _{sk_end} -t _{s_start} , select the satellite node connected to the starting node in the set Q, if Δt _sk (M) is within the satellite node (s,k) connection time In the continuous interval of , that is, Δt _sk (M)≤Δt _uv (t _i ,t _i+m ), u=s,v=k,t _{s_start} ≥t _i ,t _{sk_end} ≤t _i+m , then the satellite node k as the current path-finding node, and write it into the deterministic path node set P, and delete this node from the set Q; if Δt _sk (M)＞Δt _uv (t _i ,t _i+m ), u= s, v=k, that is, the task traffic cannot complete the transmission within the continuous interval of the satellite node (s, k) connection time, then the satellite node k does not meet the requirements;

同时满足节点k的缓存约束：

则该任务业务量传输时间Δt_kj(M)＝t_{kj_end}-t_{kj_start}，若Δt_kj(M)在卫星节点(k,j)连通时间的连续区间内，即Δt_kj(M)≤Δt_uv(t_i,t_i+m),u＝k,v＝j,t_{kj_start}≥t_i,t_{kj_end}≤t_i+m，则将卫星节点j作为当前的寻路节点，并写入确定性路径节点集合P中，并将该节点从集合Q中删除；若Δt_kj(M)＞Δt_uv(t_i,t_i+m),u＝k,v＝j，则表示该任务业务量不能在卫星节点(k,j)连通时间的连续区间内完成传输，则卫星节点j不满足要求；If the starting node of the pathfinding is the intermediate node k of the satellite network, the next hop satellite node j connected to the node k in the set Q, the starting time of its continuous connection time is t _{kj_start} , t _{s_start} <t _{kj_start} ≤ t _{sk_end} ; According to the link capacity C(k,j) between the starting node and the connected satellite node, calculate the transmission end time t _{kj_end} of the task traffic on the satellite link, and the calculation method is:

Simultaneously satisfy the cache constraint of node k:

Then the task traffic transmission time Δt _kj (M) = t _{kj_end} -t _{kj_start} , if Δt _kj (M) is within the continuous interval of the satellite node (k, j) connection time, that is, Δt _kj (M)≤Δt _uv ( t _i ,t _i+m ),u=k,v=j,t _{kj_start} ≥t _i ,t _{kj_end} ≤t _i+m , then take the satellite node j as the current path-finding node and write it into the deterministic path node in the set P, and delete the node from the set Q; if Δt _kj (M)>Δt _uv (t _i ,t _i+m ), u=k, v=j, it means that the task traffic cannot be If the transmission is completed within the continuous interval of the connection time of node (k, j), the satellite node j does not meet the requirements;

If j=D, that is, when the destination satellite node is found, the path finding ends; if j≠D, that is, when the destination satellite node is not found, the path finding is performed again.

A path planning method for ensuring end-to-end deterministic delay of a satellite network, comprising:

S1. Determine the task requirements; determine the capacity parameter C(t) of the inter-satellite link of the satellite network at different times;

S2. Calculate the basic unit time of all business transmissions included in the task as time slots, calculate the basic unit time τ, and use the basic unit time as time slots to divide the task action time domain;

S3. Obtain the connectivity diagram of all satellite nodes in the task action time domain T;

S4. Set the deterministic path node set as P, take the task access satellite node as the source node S, and write this node into the deterministic path node set P;

S5. Set all satellite nodes in the satellite network except the source node S as a set Q, and judge whether the set Q is empty, if it is empty, proceed to step S7; if not empty, proceed to step S6

S6. Taking the task access time as the starting time t _s-start , according to the service transmission time Δt(M), the satellite node buffer capacity Buffer(u) and the connection time between satellite nodes Δt _uv (t _i ,t _i+m ) The relationship between determines the next hop satellite node;

则表示不存在符合条件的路径，寻路结束。S7. Determine whether the deterministic path node set P is the final deterministic path set; if the destination satellite node D is in the deterministic path node set P, that is, D∈P, then the pathfinding ends, and the deterministic path node set P The satellite nodes in the path are combined into paths in sequence, and the transmission time of the task traffic between each node is recorded, which is the end-to-end transmission deterministic delay of the path; if

It means that there is no path that meets the condition, and the pathfinding ends.

Preferably, the task requirements include the task traffic volume M, the task contains the business category N, the traffic volume of each business is V _i (i=1, 2, ..., N), the mission start access satellite node S, the mission destination satellite node Node D, task action time domain T.

Preferably, according to the connection relationship diagram of all satellite nodes in the task action time domain T, the continuous connection time between any two satellite nodes (u, v) at any m moments (t _i , t _i+m ) can be obtained Δt _uv (t _i ,t _i+m ), m∈(1,2,...,n).

Preferably, the basic unit time τ is calculated by using the greatest common divisor v _φ of all traffic in the task and the capacity parameter C(t) of the inter-satellite link.

Preferably, step S6 is specifically:

则该任务业务量传输时间Δt_sk(M)＝t_{sk_end}-t_{s_start}，在集合Q中选取与起始节点所连通的卫星节点，若Δt_sk(M)在卫星节点(s,k)连通时间的连续区间内，即Δt_sk(M)≤Δt_uv(t_i，t_i+m)，u＝s，v＝k，t_{s_start}≥t_i，t_{sk_end}≤t_i+m，则将卫星节点k作为当前的寻路节点，并写入确定性路径节点集合P中，并将该节点从集合Q中删除；若Δt_sk(M)＞Δt_uv(t_i,t_i+m),u＝s,v＝k，即该任务业务量不能在卫星节点(s,k)连通时间的连续区间内完成传输，则卫星节点k不满足要求，返回步骤S5；S61. If the starting node of the pathfinding is the task access satellite source node S, then the starting time is the task access time t _{s_start} . According to the link capacity C(s,k) between the starting node and the connected satellite node, Calculate the transmission end time t _{sk_end} of the task traffic on the satellite link, and the calculation method is:

Then the task traffic transmission time Δt _sk (M) = t _{sk_end} -t _{s_start} , select the satellite node connected to the starting node in the set Q, if Δt _sk (M) is within the satellite node (s,k) connection time In the continuous interval of , that is, Δt _sk (M)≤Δt _uv (t _i , t _i+m ), u=s, v=k, t _{s_start} ≥t _i , t _{sk_end} ≤t _i+m , then the satellite node k as the current path-finding node, and write it into the deterministic path node set P, and delete this node from the set Q; if Δt _sk (M)＞Δt _uv (t _i ,t _i+m ), u= s, v=k, that is, the task traffic cannot be transmitted within the continuous interval of the satellite node (s, k) connection time, then the satellite node k does not meet the requirements, and returns to step S5;

同时满足节点k的缓存约束：

则该任务业务量传输时间Δt_kj(M)＝t_{kj_end}-t_{kj_start}，若Δt_kj(M)在卫星节点(k,j)连通时间的连续区间内，即Δt_kj(M)≤Δt_uv(t_i,t_i+m),u＝k,v＝j,t_{kj_start}≥t_i,t_{kj_end}≤t_i+m，则将卫星节点j作为当前的寻路节点，并写入确定性路径节点集合P中，并将该节点从集合Q中删除；若Δt_kj(M)＞Δt_uv(t_i,t_i+m),u＝k,v＝j，则表示该任务业务量不能在卫星节点(k,j)连通时间的连续区间内完成传输，则卫星节点j不满足要求，返回步骤S5；S62. If the starting node of the pathfinding is the intermediate node k of the satellite network, the next hop satellite node j connected to the node k in the set Q, the starting time of its continuous connection time is t _{kj_start} , t _{s_start} <t _{kj_start} ≤t _{sk_end} ; According to the link capacity C(k ^, j) between the starting node and the connected satellite node, calculate the transmission end time t _{kj_end} of the task traffic on the satellite link, and the calculation method is:

Simultaneously satisfy the cache constraint of node k:

Then the task traffic transmission time Δt _kj (M) = t _{kj_end} -t _{kj_start} , if Δt _kj (M) is within the continuous interval of the satellite node (k, j) connection time, that is, Δt _kj (M)≤Δt _uv ( t _i ,t _i+m ),u=k,v=j,t _{kj_start} ≥t _i ,t _{kj_end} ≤t _i+m , then take the satellite node j as the current path-finding node and write it into the deterministic path node in the set P, and delete the node from the set Q; if Δt _kj (M)>Δt _uv (t _i ,t _i+m ), u=k, v=j, it means that the task traffic cannot be If the transmission is completed within the continuous interval of the connection time of node (k, j), then the satellite node j does not meet the requirements, and returns to step S5;

S63 If j=D, that is, when the route is found to the destination satellite node, then the route finding ends, and proceed to step S7; if j≠D, that is, when the destination satellite node is not found, then return to step S5.

A computer-readable storage medium, on which computer program instructions are stored, and when the computer program instructions are loaded and run by a processor, the processor executes the above-mentioned path planning that guarantees the end-to-end deterministic delay of the satellite network method.

Compared with the prior art, the present invention has the following beneficial effects:

(1) The present invention calculates the transmission time slot according to the traffic volume and the cumulative flow of the satellite link, and divides the task action time domain with this time slot, and then establishes the satellite network time according to the connection relationship and connection duration of the satellite network nodes in the time slot Continuous graph; based on the size of the task business volume, the start time and end time of business transmission, the connection link capacity of the satellite node and the storage occupancy of the satellite node as constraints, a path planning calculation method is formed; and the task access satellite node is used as the first hop starting point, In all connected adjacent nodes, the next hop path node is found according to the path calculation method until the destination node, thereby obtaining the deterministic transmission path of the satellite network, eliminating the waiting delay caused by service storage, and realizing the multi-type service. Deterministic transfer.

(2) The method of the present invention proposes a satellite network spatio-temporal map construction method oriented to service characteristics, calculates the transmission time slot according to the traffic volume and the cumulative flow of satellite link transmission, divides the task action time domain based on this time slot, and divides the time period The space-time map of the satellite network is established based on the connection relationship of satellite nodes, which can accurately adapt to the transmission requirements of different characteristic services.

(3) The method of the present invention carries out transmission time slot calculation according to different satellite network service characteristics, obtains the time slot occupation of different services, guarantees that the service data packet can be completely transmitted within the connection time of the satellite node, and eliminates the problem that the service is caused by waiting for the link to be connected Latency is uncertain.

(4) The method of the present invention determines the start and end time of service transmission according to the cumulative flow of links between different satellite nodes, accurately describes the relationship between the service flow transmission time and the connection time of satellite nodes, and constructs a deterministic delay path with time attributes, ensuring time End-to-end deterministic transmission of services under variable link conditions.

(5) The method of the present invention considers the time-varying characteristics of the links between satellite nodes, calculates the service transmission time according to the cumulative traffic of the link, and realizes the certainty of the service under the dynamic link change condition by accurately controlling the initial transmission time of the upstream and downstream satellite nodes transmission.

Description of drawings

Figure 1 is a schematic diagram of the composition of the satellite network topology.

Figure 2 is a connection diagram of satellite nodes.

Detailed ways

In order to make the object, technical solution and advantages of the present invention clearer, the implementation manner of the present invention will be further described in detail below in conjunction with the accompanying drawings.

A path planning method to ensure the end-to-end deterministic delay of the satellite network. First, construct the space-time map of the satellite network based on the service characteristics, calculate the transmission time slot according to the mission traffic and the capacity of the satellite link, and use this time slot to affect the mission. The time domain is divided, and then the satellite network space-time diagram is established according to the connection relationship and connection duration of the satellite network nodes in the time slot; Satellite node resource allocation (such as storage occupancy) is a constraint condition, and the path planning calculation method is determined by the business transmission start and end time and link connection time; finally, the task access satellite node is used as the first hop starting point, and all connected According to the path planning calculation method, the adjacent nodes find the next hop path node until the destination node, thereby obtaining the deterministic transmission path of the satellite network, thus forming a satellite network path planning method with deterministic delay guarantee.

Example 1:

A path planning method for ensuring end-to-end deterministic delay of a satellite network, comprising:

S1. When a task with a deterministic delay guarantee requirement starts, the user initiates a task requirement and notifies the satellite network management center. The task requirement includes task traffic M, and the task includes service category N, and the traffic volume of each service is V _i (i= 1, 2, ..., N), mission start access satellite node S, mission destination satellite node D, mission action time domain T and other parameter information, the satellite network management center can obtain the satellite network inter-satellite link capacity parameter C at different times (t);

以此基本单位时间为时隙对任务作用时间域进行划分，得到的时刻数目为n，

即t₁，t₂，…t_n。S2. The basic unit time of all business transmissions included in the calculation task is a time slot, and the basic unit time τ is calculated with the greatest common divisor v _φ of all traffic volumes included in the task and the capacity parameter C(t) of the inter-satellite link,

Using this basic unit of time as the time slot to divide the task action time domain, the number of time obtained is n,

That is, t ₁ , t ₂ , . . . t _n .

S3. According to the satellite network topology, obtain the connection relationship diagram of all satellite nodes in the task action time domain T, and obtain any two satellite nodes (u, v) between any m moments (t _i , t _i+m ) The continuous connection time Δt _uv (t _i ,t _i+m ), m∈(1,2,…,n);

S4. Set the deterministic path node set as P, take the task access satellite node as the source node S, and write this node into the deterministic path node set P;

S5. Set all the satellite nodes in the satellite network except the source node S as the set Q, and judge whether the set Q is empty, if it is empty, go to step S7; if not, go to step S6.

S6. Taking the task access time as the starting time t _s-start , according to the service transmission time Δt(M), the satellite node buffer capacity Buffer(u) and the connection time between satellite nodes Δt _uv (t _i ,t _i+m ) The relationship determines the next hop satellite node. Step S6 is specifically:

则该任务业务量传输时间Δt_sk(M)＝t_{sk_end}-t_{s_start}，在集合Q中选取与起始节点所连通的卫星节点，若Δt_sk(M)在卫星节点(s,k)连通时间的连续区间内，即Δt_sk(M)≤Δt_uv(t_i,t_i+m),u＝s,v＝k,t_{s_start}≥t_i,t_{sk_end}≤t_i+m，则将卫星节点k作为当前的寻路节点，并写入确定性路径节点集合P中，并将该节点从集合Q中删除。若Δt_sk(M)＞Δt_uv(t_i,t_i+m),u＝s,v＝k，即该任务业务量不能在卫星节点(s,k)连通时间的连续区间内完成传输，则卫星节点k不满足要求，返回步骤S5。S61 If the starting node of the pathfinding is the task access satellite source node S, then the starting time is the task access time t _{s_start} , and according to the link capacity C(s,k) between the starting node and the connected satellite node, calculate Calculate the transmission end time t _{sk_end} of the task traffic on the satellite link, and the calculation method is:

Then the task traffic transmission time Δt _sk (M) = t _{sk_end} -t _{s_start} , select the satellite node connected to the starting node in the set Q, if Δt _sk (M) is within the satellite node (s,k) connection time In the continuous interval of , that is, Δt _sk (M)≤Δt _uv (t _i ,t _i+m ), u=s,v=k,t _{s_start} ≥t _i ,t _{sk_end} ≤t _i+m , then the satellite node k is used as the current path-finding node, and is written into the deterministic path node set P, and the node is deleted from the set Q. If Δt _sk (M)>Δt _uv (t _i ,t _i+m ), u=s, v=k, that is, the task traffic cannot be transmitted within the continuous interval of the satellite node (s, k) connection time, Then the satellite node k does not meet the requirements, and returns to step S5.

同时满足节点k的缓存约束：

则该任务业务量传输时间Δt_kj(M)＝t_{kj_end}-t_{kj_start}，若Δt_kj(M)在卫星节点(k,j)连通时间的连续区间内，即Δt_kj(M)≤Δt_uv(t_i,t_i+m),u＝k,v＝j,t_{kj_start}≥t_i,t_{kj_end}≤t_i+m，则将卫星节点j作为当前的寻路节点，并写入确定性路径节点集合P中，并将该节点从集合Q中删除。若Δt_kj(M)＞Δt_uv(t_i,t_i+m),u＝k,v＝j，则表示该任务业务量不能在卫星节点(k,j)连通时间的连续区间内完成传输，则卫星节点j不满足要求，返回步骤S5。S62 If the starting node of the pathfinding is the intermediate node k of the satellite network, the next hop satellite node j connected to the node k in the set Q, the starting time of its continuous connection time is t _{kj_start} , t _{s_start} <t _{kj_start ≤tsk_end} . According to the link capacity C(k,j) between the starting node and the connected satellite node, calculate the transmission end time t _{kj_end} of the task traffic on the satellite link, and the calculation method is:

Simultaneously satisfy the cache constraint of node k:

Then the task traffic transmission time Δt _kj (M) = t _{kj_end} -t _{kj_start} , if Δt _kj (M) is within the continuous interval of the satellite node (k, j) connection time, that is, Δt _kj (M)≤Δt _uv ( t _i ,t _i+m ),u=k,v=j,t _{kj_start} ≥t _i ,t _{kj_end} ≤t _i+m , then take the satellite node j as the current path-finding node and write it into the deterministic path node In the set P, and delete the node from the set Q. If Δt _kj (M)>Δt _uv (t _i ,t _i+m ), u=k, v=j, it means that the task traffic cannot be transmitted within the continuous interval of the satellite node (k, j) connection time , then the satellite node j does not meet the requirements, return to step S5.

S63 If j=D, that is, when the route is found to the destination satellite node, then the route finding ends, and proceed to step S7; if j≠D, that is, when the destination satellite node is not found, then return to step S5.

则表示不存在符合条件的路径，寻路结束。S7. Determine whether the deterministic path node set P is the final deterministic path set. If the destination satellite node D is in the deterministic path node set P, that is, D ∈ P, the pathfinding ends, the satellite nodes in the deterministic path node set P are combined into a path in sequence, and the task traffic is recorded at each node The transmission time between is the end-to-end transmission deterministic delay of the path; if

It means that there is no path that meets the condition, and the pathfinding ends.

Example 2:

A path planning method for ensuring end-to-end deterministic delay of a satellite network, comprising:

S1. When a task with a deterministic delay guarantee requirement starts, the user initiates a task requirement to notify the satellite network management center. The task requirement includes the task traffic M being 2 units of data, the task includes business types N=2, and the business rate is V ₁ ＝V ₂ ＝1 unit of data, mission start access satellite node A, mission destination satellite node D, mission action time domain T is divided into 6 unit time and other parameter information, the satellite network intersatellite link obtained by the satellite network management center The road capacity parameter C(t) is 1 unit of data;

得到τ＝1。以此基本单位时间对任务作用时间域进行划分，得到的时刻数目为n，

即(t₀,t₁,t₂,t₃,t₄,t₅)。S2. The calculation task includes the basic unit time of all business transmissions, and calculates the basic unit time τ with the task including the greatest common divisor v _φ =1 of all traffic volumes and the inter-satellite link capacity parameter C(t),

τ=1 is obtained. Based on this basic unit time, the task action time domain is divided, and the number of moments obtained is n,

That is (t ₀ , t ₁ , t ₂ , t ₃ , t ₄ , t ₅ ).

S3. Assume that the satellite network topology contains 4 satellite nodes, as shown in Figure 1, obtain the connection relationship diagram of all satellite nodes in the task action time domain T, you can get (t _i , t _i+m ) of continuous connectivity time Δt _uv (t _i ,t _i+m ), m∈(1,2,…,n), as shown in Figure 2;

S4. Set the deterministic path node set as P, take the task access satellite node as the source node A, and write this node into the deterministic path node set P, that is, P={A};

S5. Set the set of all satellite nodes in the satellite network except the source node A as Q={B, C, D}, and judge that the set Q is not empty, then go to step S6.

S6. Taking the task access time as the starting time t _{s_start} , according to the relationship between the service transmission time Δt(M), the satellite node buffer capacity Buffer(u) and the connection time between satellite nodes Δt _uv (t _i ,t _i+m ) Determine the next hop satellite node. Step S6 is specifically:

S61 According to step S4, the starting node of the pathfinding is the task access satellite source node A, and the starting time is the task access time t ₀ . Here, for the convenience of calculation, assuming that the traffic is transmitted at the full rate of the link capacity, then The transmission time of the task traffic on the satellite link is Δt(M)=2 unit times, and the transmission end time on the satellite link is t ₂ . In the satellite nodes (B, C) that are all connected to the starting node A, in the two links of L _AB and L _AC , the link of L _AC does not have a connection time period starting from time t ₀ , and the link of L _AB The connection time period of the road is [t ₀ -t ₂ ], then Δt _AB (t ₀ ,t ₂ )=Δt(M), satisfying that the traffic of the task is transmitted within the continuous interval of the connection time, t _{sk_end} =t ₂ , then take the satellite node B as the current pathfinding node and write it into the deterministic path node set P, that is, P={A,B}, and delete the satellite node B from the set Q, that is, Q={C, D}.

S62 According to step S61, the current pathfinding node B is the satellite network intermediate node k=B, and the next-hop satellite nodes j=C, D connected to this node. In all satellite nodes (C, D) connected to satellite node B, the starting time t _{kj_start} of its continuous connection time should satisfy t _{s_start} <t _{kj_start} ≤ t _{sk_end} , and the connection time should satisfy Δt _kj (M)≥Δt( M).

In the two links of L _{BC and LBD} , the connection time period of the _LBD link is [t ₃ -t ₅ ], t ₀ <t ₃ >t ₂ , which does not satisfy the transmission condition. And the connection time period of the L _BC link is [t ₁ -t ₄ ], then Δt _BC (t ₁ ,t ₄ )>Δt(M), and t ₀ <t ₁ ≤t ₂ , the starting point of the continuous connection time is The starting time is t _{kj_start} = t ₁ , t _{kj_end} = t ₃ , and the task traffic is satisfied to complete the transmission within the continuous interval of the connection time, then the satellite node C is used as the current path-finding node and written into the deterministic path In the node set P, that is, P={A, B, C}, delete the satellite node C from the set Q, that is, Q={D}.

S63 According to step S62, the current pathfinding node C is the satellite network intermediate node k=C, and the next-hop satellite node j=D connected to this node. In satellite nodes D that are all connected to satellite node C, the starting time t _{kj_start} of its continuous connection time should satisfy t _{s_start} <t _{kj_start} ≤ t _{sk_end} , and the connection time should satisfy Δt _kj (M)≥Δt(M).

The connection time period of the _LCD link is [t ₀ -t ₁ ] and [t ₂ -t ₄ ], where Δt _CD (t ₀ ,t ₁ )<Δt(M), does not meet the transmission condition. But Δt _CD (t ₂ ,t ₄ )=Δt(M), and t ₁ <t ₂ ≤t ₃ , the starting time of its continuous connection time is t _{kj_start} =t ₂ , t _{kj_end} =t ₄ , satisfying the If the task traffic is transmitted within the continuous interval of the connection time, the satellite node D is used as the current pathfinding node and written into the deterministic path node set P, that is, P={A,B,C,D}, Delete the satellite node D from the set Q, namely

S64 According to the satellite node j=D obtained in step S63, that is, the route is found to the destination satellite node, then the route finding ends, and step S7 is performed.

S7. Determine whether the deterministic path node set P is the final deterministic path set. D∈P, then the pathfinding ends, the satellite nodes in the deterministic path node set P are combined into a path in sequence, that is, A→B→C→D, and the transmission time of the task traffic between nodes is recorded, namely is the end-to-end deterministic transmission delay of the path, and the delay value is t ₄ −t ₀ =4 unit times.

The content that is not described in detail in the description of the present invention belongs to the well-known technology of those skilled in the art.

Although the present invention has been disclosed as above with preferred embodiments, it is not intended to limit the present invention, and any person skilled in the art can use the methods disclosed above and technical content to analyze the present invention without departing from the spirit and scope of the present invention. Possible changes and modifications are made in the technical solution. Therefore, any simple modification, equivalent change and modification made to the above embodiments according to the technical essence of the present invention, which do not depart from the content of the technical solution of the present invention, all belong to the technical solution of the present invention. protected range.

Claims (10)

1. A path planning method that guarantees satellite network end-to-end deterministic delay, is characterized in that, comprises: Calculate the transmission time slot according to the task traffic and satellite link capacity, and divide the task action time domain according to this time slot, and then establish the satellite network space-time diagram according to the connection relationship and connection duration of the satellite network nodes in the time slot; Take the task access satellite node as the first hop starting point, find the next hop path node in all connected adjacent nodes according to the path planning method, until the destination node, thereby obtaining the deterministic transmission path of the satellite network, thus forming a deterministic Satellite network path planning method with permanent delay guarantee; The path planning method is specifically: taking the size of the task traffic, the link capacity of the satellite node connection, and the resource allocation of the satellite node as the constraint conditions, and taking the start and end time of the service transmission and the link connection time as the judgment conditions to perform path planning. 2. path planning method according to claim 1, is characterized in that, comprises the greatest common divisor v _φ of all traffic volumes and inter-satellite link capacity parameter C (t) with task and calculates basic unit time τ; With this basic unit Time is the time slot to divide the task action time domain. 3. The path planning method according to claim 1, characterized in that, according to the satellite network space-time diagram, it is possible to obtain any two satellite nodes (u, v) between any m moments (t _i , t _i+m ) of continuous connection time Δt _uv (t _i ,t _i+m ). 4. The path planning method according to any one of claims 1 to 3, wherein the path planning method is specifically: If the starting node of the pathfinding is the task access satellite source node S, then the starting time is the task access time t _{s_start} , according to the link capacity C(s,k) between the starting node and the connected satellite node, calculate The transmission end time t _{sk_end} of the task traffic on the satellite link is calculated as:

Then the task traffic transmission time Δt _sk (M) = t _{sk_end} -t _{s_start} , select the satellite node connected to the starting node in the set Q, if Δt _sk (M) is within the satellite node (s,k) connection time In the continuous interval of , that is, Δt _sk (M)≤Δt _uv (t _i ,t _i+m ), u=s,v=k,t _{s_start} ≥t _i ,t _{sk_end} ≤t _i+m , then the satellite node k as the current path-finding node, and write it into the deterministic path node set P, and delete this node from the set Q; if Δt _sk (M)＞Δt _uv (t _i ,t _i+m ), u= s, v=k, that is, the task traffic cannot complete the transmission within the continuous interval of the satellite node (s, k) connection time, then the satellite node k does not meet the requirements; If the starting node of the pathfinding is the intermediate node k of the satellite network, the next hop satellite node j connected to the node k in the set Q, the starting time of its continuous connection time is t _{kj_start} , t _{s_start} <t _{kj_start} ≤ t _{sk_end} ; According to the link capacity C(k,j) between the starting node and the connected satellite node, calculate the transmission end time t _{kj_end} of the task traffic on the satellite link, and the calculation method is:

Simultaneously satisfy the cache constraint of node k:

Then the task traffic transmission time Δt _kj (M) = t _{kj_end} -t _{kj_start} , if Δt _kj (M) is within the continuous interval of the satellite node (k, j) connection time, that is, Δt _kj (M)≤Δt _uv ( t _i ,t _i+m ),u=k,v=j,t _{kj_start} ≥t _i ,t _{kj_end} ≤t _i+m , then take the satellite node j as the current path-finding node and write it into the deterministic path node in the set P, and delete the node from the set Q; if Δt _kj (M)>Δt _uv (t _i ,t _i+m ), u=k, v=j, it means that the task traffic cannot be If the transmission is completed within the continuous interval of the connection time of node (k, j), the satellite node j does not meet the requirements; If j=D, that is, when the destination satellite node is found, the path finding ends; if j≠D, that is, when the destination satellite node is not found, the path finding is performed again. 5. A path planning method for ensuring end-to-end deterministic delay of a satellite network, characterized in that it comprises: S1. Determine the task requirements; determine the capacity parameter C(t) of the inter-satellite link of the satellite network at different times; S2. Calculate the basic unit time of all business transmissions included in the task as time slots, calculate the basic unit time τ, and use the basic unit time as time slots to divide the task action time domain; S3. Obtain the connectivity diagram of all satellite nodes in the task action time domain T; S4. Set the deterministic path node set as P, take the task access satellite node as the source node S, and write this node into the deterministic path node set P; S5. Set all satellite nodes in the satellite network except the source node S as a set Q, and judge whether the set Q is empty, if it is empty, proceed to step S7; if not empty, proceed to step S6 S6. Taking the task access time as the starting time t _s-start , according to the service transmission time Δt(M), the satellite node buffer capacity Buffer(u) and the connection time between satellite nodes Δt _uv (t _i ,t _i+m ) The relationship between determines the next hop satellite node; S7. Determine whether the deterministic path node set P is the final deterministic path set; if the destination satellite node D is in the deterministic path node set P, that is, D∈P, then the pathfinding ends, and the deterministic path node set P The satellite nodes in the path are combined into paths in sequence, and the transmission time of the task traffic between each node is recorded, which is the end-to-end transmission deterministic delay of the path; if

It means that there is no path that meets the condition, and the pathfinding ends. 6. The path planning method according to claim 5, wherein the task requirements include task traffic M, the task includes service category N, and the traffic of each kind of business is V _i (i=1, 2, ..., N ), mission start access satellite node S, mission destination satellite node D, and mission action time domain T. 7. The path planning method according to claim 5, characterized in that, according to the connectivity diagrams of all satellite nodes in the task action time domain T, any two satellite nodes (u, v) between any m moments can be obtained The continuous connection time Δt _uv (t _i ,t _i+m ) between (t _i ,t _i+m ), m∈(1,2,…,n). 8. The path planning method according to claim 5, wherein the basic unit time τ is calculated with the greatest common divisor v _φ of all traffic volumes included in the task and the capacity parameter C(t) of the inter-satellite link. 9. The path planning method according to any one of claims 5 to 8, characterized in that step S6 is specifically: S61. If the starting node of the pathfinding is the task access satellite source node S, then the starting time is the task access time t _{s_start} . According to the link capacity C(s,k) between the starting node and the connected satellite node, Calculate the transmission end time t _{sk_end} of the task traffic on the satellite link, and the calculation method is:

Then the task traffic transmission time Δt _sk (M) = t _{sk_end} -t _{s_start} , select the satellite node connected to the start node in the set Q, if Δt _sk (M) is within the satellite node (s,k) connection time In the continuous interval of , that is, Δt _sk (M)≤Δt _uv (t _i , t _i+m ), u=s, v=k, t _{s_start} ≥t _i , t _{sk_end} ≤t _i+m , then the satellite node k as the current path-finding node, and write it into the deterministic path node set P, and delete this node from the set Q; if Δt _sk (M)＞Δt _uv (t _i ,t _i+m ), u= s, v=k, that is, the task traffic cannot be transmitted within the continuous interval of the satellite node (s, k) connection time, then the satellite node k does not meet the requirements, and returns to step S5; S62. If the starting node of the pathfinding is the intermediate node k of the satellite network, the next hop satellite node j connected to the node k in the set Q, the starting time of its continuous connection time is t _{kj_start} , t _{s_start} <t _{kj_start} ≤t _{sk_end} ; According to the link capacity C(k,j) between the starting node and the connected satellite node, calculate the transmission end time t _{kj_end} of the task traffic on the satellite link, and the calculation method is:

Simultaneously satisfy the cache constraint of node k:

Then the task traffic transmission time Δt _kj (M) = t _{kj_end} -t _{kj_start} , if Δt _kj (M) is within the continuous interval of the satellite node (k,j) connection time, that is, Δt _kj (M)≤Δt _uv ( t _i ,t _i+m ),u=k,v=j,t _{kj_start} ≥t _i ,t _{kj_end} ≤t _i+m , then take the satellite node j as the current path-finding node and write it into the deterministic path node in the set P, and delete the node from the set Q; if Δt _kj (M)>Δt _uv (t _i ,t _i+m ), u=k, v=j, it means that the task traffic cannot be If the transmission is completed within the continuous interval of the connection time of node (k, j), then the satellite node j does not meet the requirements, and returns to step S5; S63 If j=D, that is, when the route is found to the destination satellite node, then the route finding ends, and proceed to step S7; if j≠D, that is, when the destination satellite node is not found, then return to step S5. 10. A computer-readable storage medium, on which computer program instructions are stored, and when the computer program instructions are loaded and run by a processor, the processor is executed as described in any one of claims 1 to 3. Methods.

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