CN113950104B - A deterministic scheduling method for satellite network services based on dynamic period mapping - Google Patents

Abstract

A satellite network service deterministic scheduling method based on dynamic period mapping includes dividing service grades according to different service requirements, obtaining parameter characteristics of each grade of service, identifying and classifying the service accessed to a satellite network, shaping into different grade service queues, calculating service average rate of each queue, obtaining transmission time of each service queue, dividing forwarding time of satellite nodes, determining transmission period of each queue, determining period mapping relation table among satellite nodes according to satellite network topology, finally accessing service identification period labels, carrying out service forwarding according to service carrying label searching period mapping relation table by satellite nodes, guaranteeing transmission of each service in fixed period of each satellite node, accurately controlling forwarding time of each service, and realizing deterministic transmission of multiple services.

Description

A deterministic scheduling method for satellite network services based on dynamic period mapping

Technical field

The invention relates to a deterministic scheduling method for satellite network services based on dynamic periodic mapping, and belongs to the technical field of satellite communications.

Background technique

With the integration and development of space information networks and ground networks, a large number of terrestrial mobile communication services (such as AR/VR, 4K/8K, high-reliability industrial Internet services, etc.), space intelligence services, and command and control services have experienced a sharp increase in data volume. New services are constantly integrated into spatial information networks, and there are huge differences in the characteristics and service quality requirements of multiple types of services. Therefore, in the context of many services being transmitted simultaneously through spatial information networks, it is difficult to ensure the deterministic service quality (bounded) of highly reliable services. delay and delay jitter) put forward new requirements.

At present, spatial information network exchange and transmission protocols (such as CCSDS, DTN or customized spatial information network protocols) are developed based on the TCP/IP network protocol family. The traditional TCP/IP protocol adopts "best effort" transmission and storage and forwarding methods. Only connection-less, unreliable packet delivery capabilities are provided. Existing methods ensure service quality by setting priorities, reserving bandwidth, etc., but these methods have the following shortcomings:

(1) Adopt the same scheduling strategy for all services, so that when different services arrive at the same time, they will cause micro-bursts due to competition for resources. Under multi-hop accumulation, the forwarding of service data packets will be uncontrollable, and the certainty of different services cannot be guaranteed. Service quality requirements such as latency;

(2) Regarding the priority setting method, when the length of the low-priority service data packet is too large, the high-priority service data packet needs to be stored and waited, which cannot meet the deterministic quality of service requirements.

(3) The resource reservation method performs bandwidth reservation and other operations for all business flows, does not differentiate services in detail, and cannot provide packet-level QoS guarantee;

At the same time, the dynamic nature of satellite network topology and wireless transmission of inter-satellite links will cause changes in service rates and transmission delays, thus posing new challenges to the deterministic transmission of services.

Contents of the invention

The technical problem to be solved by the present invention is to overcome the shortcomings of the existing technology and provide a deterministic scheduling method for satellite network services based on dynamic periodic mapping. First, the service levels are divided according to different business service requirements, and the service levels of each level of business are obtained. Parameter characteristics, and then identify and classify the services connected to the satellite network, thereby shaping them into different levels of service queues, calculating the average service rate of each queue, obtaining the transmission time of each service queue, and then dividing the forwarding time of the satellite nodes , determine the transmission period of each queue, and determine the period mapping relationship table between satellite nodes according to the satellite network topology. Finally, identify the period label for the access service, and the satellite node searches the period mapping relationship table according to the label carried by the service to forward the service, ensuring Each service is transmitted within a fixed period of each satellite node, and the forwarding time of each service is precisely controlled to achieve deterministic transmission of multiple services.

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

A deterministic scheduling method for satellite network services based on dynamic period mapping, including the following steps:

S1. The satellite network management and control center divides deterministic services into service levels according to service quality requirements, and obtains the traffic characteristic parameters of each level;

S2. Classify and identify satellite network services according to the traffic characteristic parameters in step S1, and shape them into service queues of different levels, and calculate the average service rate of each queue;

S3. Calculate the service transmission time of each queue at each satellite node based on the average service rate in step S2;

S4. The satellite node divides the transmission time of each satellite node according to the transmission time of each queue in step S3, and determines the periodic mapping relationship table of service queues between satellite network nodes;

S5. According to the period mapping relationship table in S4, the service data in different levels of queues are identified with corresponding period tags when accessing the satellite network;

S6. The satellite network forwarding node extracts the periodic label carried by each service, finds the transmission period corresponding to the periodic label according to the periodic mapping relationship table, and then forwards the service to the downstream node in this period.

Preferably, in step S1, the service levels are divided according to service quality requirements to include text services, image services, and video services.

Preferably, the traffic characteristic parameters of each level in step S1 include at least the duration of data packets, the average interval of arrival of data packets, the size of data packets, and the total number of packet packets of each level of service.

Preferably, in step S2, an artificial intelligence algorithm is used to classify and identify satellite network services based on the traffic characteristic parameters in step S1.

Preferably, in step S4, the satellite node divides the transmission time of each satellite node according to the transmission time of each queue in step S3, and determines the periodic mapping relationship table of service queues between satellite network nodes; specifically including:

S41. Calculate the transmission time of different satellite forwarding nodes based on the reserved bandwidth and output link rate of each satellite forwarding node;

S42. According to the service queue transmission time obtained in S3, divide the transmission time of each satellite forwarding node and determine the transmission period of different service queues at the satellite forwarding node;

S43. Obtain the distance between any two satellite nodes and the distance offset between satellite nodes according to the characteristics of the satellite network, thereby obtaining the link transmission delay, the offset of the periodic relationship between satellite nodes, and the forwarding cycle delay time of the downstream satellite node; finally Obtain the periodic mapping relationship table between different satellite forwarding nodes.

Preferably, in step S42, the specific method of dividing the transmission time of each satellite forwarding node is: taking the greatest common divisor of the transmission periods of each service queue as the basic transmission period window, and then determining the number of transmission periods of each satellite forwarding node. and the number of basic transmission cycle windows occupied by each service queue, that is, it is determined that each service queue transmits in multiple consecutive basic transmission cycles.

A deterministic scheduling system for satellite network services based on dynamic period mapping, including:

The business service level classification module is used to divide deterministic services into business service levels according to service quality requirements, and obtain the traffic characteristic parameters of each level;

The service identification and rate calculation module classifies and identifies satellite network services according to the traffic characteristic parameters, then shapes them into service queues of different levels, and calculates the average service rate of each queue;

The service transmission time calculation module calculates the service transmission time of each queue at each satellite node based on the average service rate;

The periodic mapping relationship table determination module divides the transmission time of each satellite node according to the transmission time of each queue, and determines the periodic mapping relationship table of business queues between satellite network nodes;

The identification module identifies corresponding period labels for business data in different levels of queues when accessing the satellite network according to the period mapping relationship table;

The forwarding module searches for the transmission cycle corresponding to the cycle label carried by each service based on the cycle mapping relationship table, and then forwards the service to the downstream node in this cycle.

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

(1) The present invention simultaneously implements packet switching and circuit switching functions in the same satellite switching node, thereby ensuring the differentiated service quality requirements of different services while meeting the flexibility of business forwarding;

(2) The present invention generates a period mapping table between satellite network nodes based on service characteristics, ensuring that each service is transmitted within a fixed period of each satellite node, accurately controlling the forwarding time of each service, and realizing deterministic transmission of multiple types of services;

(3) The method for generating a satellite network dynamic period mapping table proposed by the present invention calculates the transmission time of different levels of service queues at satellite nodes, uses its greatest common denominator as the basic transmission period, and dynamically allocates and occupies the basic transmission period according to the characteristics of the service parameters. number; based on different satellite network topologies, a period mapping table is generated by calculating the offset relationship between the inter-satellite link transmission time and the basic transmission period, which can achieve deterministic transmission of different services in different satellite networks;

(4) The present invention identifies and classifies satellite network service characteristics and shapes them into different service queues. It calculates the transmission time at different satellite nodes according to different queue rates. By adjusting the number of occupied basic transmission cycles, it can meet different types of differentiation. Service quality requirements;

(5) The method of the present invention considers the dynamic changing characteristics of the satellite network topology, proposes a comparison method between the transmission time of the inter-satellite link and the basic transmission period, and realizes dynamic link changes by changing the starting transmission time of the downstream satellite network node. Deterministic transmission of services;

(6) According to the period mapping table relationship of different satellite nodes, the maximum delay jitter of data packets in this method is 2*T _c (T _c is the basic transmission period).

Description of drawings

Figure 1 is a schematic diagram of the basic transmission cycle occupied by different services.

Figure 2 is a cycle mapping relationship table.

Detailed ways

In order to make the purpose, 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.

Example 1:

A deterministic scheduling method for satellite network services based on dynamic period mapping, including:

S1. The satellite network management and control center divides business service levels according to service quality requirements, and obtains the traffic characteristic parameters of each level;

S2. Classify and identify satellite network services according to the traffic characteristic parameters in step S1, and shape them into service queues of different levels, and calculate the average service rate of each queue;

S3. Calculate the service transmission time of each queue at each satellite node based on the average service rate in step S2;

S4. The satellite node divides the transmission time of each satellite node according to the transmission time of each queue in step S3, and determines the periodic mapping relationship table of service queues between satellite network nodes;

S5. According to the period mapping relationship table in S4, the service data in different levels of queues are identified with corresponding period tags when accessing the satellite network;

S6. The satellite network forwarding node extracts the periodic label carried by each service, finds the transmission period corresponding to the periodic label according to the periodic mapping relationship table, and then forwards the service to the downstream node in this period.

Step S1 is specifically as follows:

S11. Divide business service levels, define and differentiate the services carried by satellite networks according to user service requirements and application scenarios, and divide them into deterministic services and ordinary services. Deterministic services can be divided into N levels according to different service quality requirements. , ordinary services are scheduled according to the priority criteria of the standard TCP/IP protocol, and no other operations are performed;

S12. Obtain the traffic parameters in N levels of services respectively, including the duration of data packets. Data packet arrival interval/> Data packet size/> The total number of packet messages m _i for each level of service, i=1, 2,...N.

Step S2 is specifically as follows:

Deterministic service classification and queue aggregation, classify and identify satellite network services based on the traffic parameters of N levels of services, and shape the traffic of the same level of services into N service queues, thereby obtaining the average of N deterministic service queues. Rate v _c1 ,v _c2 ,…,v _cN ,

Step S3 is specifically as follows:

The transmission period of different service queues T _ci , i=1,2,...N is the transmission time of the data message on the output link of the satellite forwarding node, and the output link rate is R, then T _ci =v _ci /R.

Step S4 is specifically as follows:

S41. Calculate the transmission time T _s (i) of different satellite forwarding nodes. The reserved bandwidth of each satellite forwarding node is B and the output link rate is R. Then its transmission time is T _s (i) = B/R;

S42. Determine the transmission period of different service queues at the satellite forwarding node. According to the service queue transmission period T _ci obtained in S3, divide the transmission time T _s (i) of each satellite forwarding node. The specific dividing method is: take each service The greatest common denominator of the queue transmission period is the basic transmission period window, that is, T _c = lcd (T _ci ), i = 1, 2,..., N, then the number of transmission periods of each satellite forwarding node The number of basic transmission cycle windows occupied by each service queue is/> That is, each business queue is continuously/> Transmit within a basic transmission cycle;

S43. Obtain the periodic mapping relationship table between different satellite forwarding nodes. If the number of satellite forwarding nodes is M, obtain the distance d _ij between any two satellite nodes according to the characteristics of the satellite network, i=1,2,...,M; j= 1,2,…,M, distance offset Δd _ij between satellite nodes, i=1,2,…,M; j=1,2,…,M, thus obtaining the link transmission delay C is the electromagnetic wave space transmission rate. Calculate the number of period offsets between satellite nodes/> and time offset T _offset , if Get the period offset number/> Time offset/> Then the forwarding cycles of the upstream and downstream satellite nodes are the same, and the downstream nodes only need to postpone the forwarding by T _offset time; if/> Get the number of period offsets Time offset/> Then the forwarding cycle of the downstream satellite node is later than the forwarding cycle of the upstream satellite node/> A basic transmission cycle, and the forwarding time needs to be delayed by T _offset time, from which the cycle mapping relationship table between satellite network nodes is calculated.

Example 2:

S1. The satellite network management and control center divides business service levels according to service quality requirements, and obtains the traffic characteristic parameters of each level;

S11. The satellite network management and control center divides business service levels, and differentiates the services carried by the satellite network according to user service requirements and application scenarios, and divides them into deterministic services and ordinary services. Services that require punctual, accurate and reliable transmission are deterministic services. And according to the deterministic delay requirements, it can be divided into 3 priority levels. The priority order from high to low is text service, image service and video service;

S12. Obtain the traffic parameter characteristics of the three levels of services respectively, including the duration of data packets, the average interval of arrival of data packets, the size of data packets, and the total number of packets for each level of business;

S2. Classify and identify satellite network services according to the traffic parameter characteristics of step S12. The identification and classification method can use artificial intelligence algorithms such as deep learning to establish a traffic characteristic matrix for intelligent learning and identification based on the traffic parameter characteristics of S12, and then perform intelligent learning and identification on the identified The services are classified and shaped into three levels of service queues, and the average service rate of the three queues is calculated. v _c1 = 8kbit/s, v _c2 = 200kbit/s, v _c3 = 80kbit/s,;

S3. Based on the average service rate in step S2, calculate the service transmission time T _ci of the three queues. If the output link rate is R=1Gbps, then T _ci =v _ci /R, i=1,2,3, that is, T _c1 =8us, T _c2 =200us, T _c3 =80us.

S4. The satellite nodes divide the transmission time of each queue according to the transmission time of each queue in step S3, and determine the periodic mapping relationship table of the service queues between satellite network nodes;

S41. Calculate the transmission time T _s (i) of different satellite forwarding nodes. The reserved bandwidth of each satellite forwarding node is B=100Mbps, and the output link rate is R=1Gbps. Then its transmission time is T _s (i)= B/R＝100Mbps/1Gbps＝0.1s;

S42. Determine the transmission period of different service queues at the satellite forwarding node. According to the service queue transmission period T _ci obtained in S3, divide the transmission time T _s (i) of each satellite forwarding node. The specific dividing method is: take each service The greatest common denominator of the queue transmission period is the basic transmission period window, that is, T _c =lcd (T _ci ) = 8us, i = 1, 2, 3, then the number of transmission cycles of each satellite forwarding node The number of basic transmission cycle windows occupied by each service queue is Therefore, the number of basic transmission windows occupied by the three queues are/> That is, each business queue is continuously/> Transmit within a basic transmission cycle, as shown in Figure 1;

S43. Obtain the periodic mapping relationship table between different satellite forwarding nodes, including the distance d _ij = 2000km between any two satellite nodes and the distance offset Δd _ij = 0.5km between any two satellite nodes according to the satellite network characteristics, thereby obtaining the link transmission time extend C is the electromagnetic wave space transmission rate. It can be seen that/> Then the periodic relationship offset between satellite nodes/> Then the forwarding cycle delay time T _offset of the downstream satellite node is obtained; thus, the cycle mapping relationship table between satellite network nodes is obtained, as shown in Figure 2.

S5. According to the period mapping relationship table in S43, the service data packets in the three-level queues are identified with corresponding period labels at the edge nodes of the satellite network;

S6. The satellite network forwarding node extracts the periodic label carried by each service, finds the transmission period corresponding to the periodic label according to the periodic mapping relationship table, and then forwards the service to the downstream node in this period.

Example 3:

A deterministic scheduling system for satellite network services based on dynamic period mapping, including:

The business service level classification module is used to divide deterministic services into business service levels according to service quality requirements, and obtain the traffic characteristic parameters of each level; the traffic characteristic parameters of each level include at least the duration of data packets and the arrival of data packets. The average interval, data packet size, and total number of packets for each level of service;

The service identification and rate calculation module classifies and identifies satellite network services according to the traffic characteristic parameters, then shapes them into service queues of different levels, and calculates the average service rate of each queue;

The service transmission time calculation module calculates the service transmission time of each queue at each satellite node based on the average service rate;

The periodic mapping relationship table determination module divides the transmission time of each satellite node according to the transmission time of each queue, and determines the periodic mapping relationship table of business queues between satellite network nodes;

The identification module identifies corresponding period labels for business data in different levels of queues when accessing the satellite network according to the period mapping relationship table;

The forwarding module searches for the transmission cycle corresponding to the cycle label carried by each service based on the cycle mapping relationship table, and then forwards the service to the downstream node in this cycle.

The periodic mapping relationship table determination module uses the following method to determine the periodic mapping relationship table of service queues between satellite network nodes:

Calculate the transmission time of different satellite forwarding nodes based on the reserved bandwidth and output link rate of each satellite forwarding node;

According to the service queue transmission time, the transmission time of each satellite forwarding node is divided to determine the transmission period of different service queues at the satellite forwarding node;

According to the characteristics of the satellite network, the distance between any two satellite nodes and the distance offset between satellite nodes are obtained, thereby obtaining the link transmission delay, the periodic relationship offset between satellite nodes, and the forwarding cycle delay time of the downstream satellite node; finally, different Periodic mapping relationship table between satellite forwarding nodes.

The specific method of dividing the transmission time of each satellite forwarding node is: taking the greatest common denominator of the transmission periods of each service queue as the basic transmission period window, and then determining the number of transmission periods of each satellite forwarding node and the proportion occupied by each service queue. The number of basic transmission cycle windows determines that each service queue will transmit in multiple consecutive basic transmission cycles.

Contents not described in detail in the specification of the present invention are well-known technologies to those skilled in the art.

Although the present invention has been disclosed above in terms of preferred embodiments, they are not intended to limit the present invention. Any person skilled in the art can utilize the methods and technical contents disclosed above to improve the present invention without departing from the spirit and scope of the present invention. Possible changes and modifications are made to the technical solution. Therefore, any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention, all belong to the technical solution of the present invention. protected range.

Claims (6)

1. A satellite network service deterministic scheduling method based on dynamic period mapping is characterized by comprising the following steps:

s1, dividing service grade of deterministic service according to service quality requirement by a satellite network management control center, and obtaining flow characteristic parameter of each grade;

s2, classifying and identifying satellite network services according to the flow characteristic parameters in the step S1, shaping the satellite network services into service queues of different grades, and calculating to obtain the average service rate of each queue;

s3, calculating the service transmission time of each queue at each satellite node according to the average service rate in the step S2;

s4, dividing the transmission time of each satellite node according to the transmission time of each queue in the step S3 by the satellite node, and determining a periodic mapping relation table of the service queues among the satellite network nodes; the method specifically comprises the following steps:

s41, calculating the transmission time of different satellite forwarding nodes according to the reserved bandwidth and the output link rate of each satellite forwarding node;

s42, dividing the transmission time of each satellite forwarding node according to the service queue transmission time obtained in the S3, and determining the transmission period of different service queues in the satellite forwarding nodes; the specific method for dividing the transmission time of each satellite forwarding node comprises the following steps: taking the greatest common divisor of the transmission periods of each service queue as a basic transmission period window, and then determining the number of the transmission periods of each satellite forwarding node and the number of the basic transmission period windows occupied by each service queue, namely determining that each service queue transmits in a plurality of continuous basic transmission periods;

s43, obtaining the distance between any two satellite nodes and the offset between the satellite nodes according to the satellite network characteristics, so as to obtain the link transmission delay, the offset of the periodic relation between the satellite nodes and the forwarding period delay time of the downstream satellite nodes; finally, a periodic mapping relation table among different satellite forwarding nodes is obtained;

s5, marking corresponding periodic labels when service data in different level queues are accessed to a satellite network according to the periodic mapping relation table in the S4;

s6, the satellite network forwarding node extracts the period label carried by each service, searches the transmission period corresponding to the period label according to the period mapping relation table, and then forwards the service to the downstream node in the period.

2. The deterministic scheduling method for satellite network traffic according to claim 1, wherein the step S1 comprises text traffic, image traffic, and video traffic after classifying the traffic service according to the quality of service requirement.

3. The method according to claim 1, wherein the traffic characteristic parameter of each class in step S1 includes at least a data message duration, an average interval of arrival of data messages, a data message size, and a total packet number of each class of traffic.

4. The deterministic scheduling method of satellite network traffic according to claim 1, wherein in step S2, the satellite network traffic is classified and identified by using an artificial intelligence algorithm according to the flow characteristic parameter of step S1.

5. A satellite network service deterministic scheduling system based on dynamic periodic mapping, comprising:

the business service grade dividing module is used for dividing deterministic business into business service grades according to the service quality requirement and obtaining the flow characteristic parameter of each grade;

the service identification and rate calculation module is used for carrying out classification identification on satellite network service according to the flow characteristic parameters, shaping the satellite network service into service queues with different grades, and calculating to obtain the average service rate of each queue;

the service transmission time calculation module calculates the service transmission time of each queue at each satellite node according to the average service rate;

the periodic mapping relation table determining module divides the transmission time of each satellite node according to the transmission time of each queue and determines the periodic mapping relation table of the service queues among the satellite network nodes; the method comprises the following steps:

calculating the transmission time of different satellite forwarding nodes according to the reserved bandwidth and the output link rate of each satellite forwarding node;

dividing the transmission time of each satellite forwarding node according to the transmission time of the service queues, and determining the transmission period of different service queues in the satellite forwarding nodes;

obtaining the distance between any two satellite nodes and the offset between the satellite nodes according to the satellite network characteristics, so as to obtain the link transmission delay, the offset of the periodic relation between the satellite nodes and the forwarding period delay time of the downstream satellite nodes; finally, a periodic mapping relation table among different satellite forwarding nodes is obtained;

the specific method for dividing the transmission time of each satellite forwarding node comprises the following steps: taking the greatest common divisor of the transmission periods of each service queue as a basic transmission period window, and then determining the number of the transmission periods of each satellite forwarding node and the number of the basic transmission period windows occupied by each service queue, namely determining that each service queue transmits in a plurality of continuous basic transmission periods;

the identification module is used for identifying corresponding periodic labels when the service data in the queues of different levels are accessed to the satellite network according to the periodic mapping relation table;

and the forwarding module searches the transmission period corresponding to the period label carried by each service according to the period mapping relation table, and forwards the service to the downstream node in the period.

6. The deterministic scheduling system for satellite network traffic according to claim 5, wherein the traffic characteristic parameter for each class comprises at least data message duration, average interval of data message arrival, data message size, total number of packet messages for each class of traffic.