A transmission delay simulation method suitable for satellite communication link

Abstract

The application discloses a transmission time delay simulation method suitable for a satellite communication link and belongs to the technical field of satellite communication simulation, and aims to solve the problem of too large error between a transmission time delay simulation result and a theoretical calculation result in the process of digital simulation of a satellite-ground transmission link of a satellite communication system under the condition of multiple links and large service data volume, and the service packets of multiple satellite communication links are accurately transmitted according to transmission time delays by using periodic judgment of a circular link and by using multiple threads. The application can be applied to transmission time delay simulation in the digital simulation of a satellite communication transmission link under the condition of multiple links and large service data volume.

Description

Technical Field

[0001] This invention relates to a method for simulating transmission delay in satellite communication links, belonging to the field of satellite communication simulation technology. Background Technology

[0002] In recent years, satellite communication system simulation technology has been continuously developing to facilitate research on satellite communication-related technologies. For simulating transmission delay in satellite communication links, many simulation software programs directly process the received service packets from the communication link by setting them for timed transmission. However, in cases of multiple links and large volumes of service data, the numerous timed tasks and the time required for task processing can easily lead to significant discrepancies between the simulated transmission delay results and the theoretical calculations. This negatively impacts subsequent digital simulations based on communication link transmission delay. Summary of the Invention

[0003] In view of this, the present invention proposes a transmission delay simulation method suitable for satellite communication links. It utilizes a circular linked list for periodic judgment and uses multi-threading to accurately send service packets of multiple satellite communication links according to the transmission delay, aiming to reduce the error between the simulation results and the theoretical calculation results of transmission delay.

[0004] To achieve the above-mentioned objectives, the technical solution adopted by this invention is as follows:

[0005] A method for simulating transmission delay in satellite communication links, used for the digital simulation of satellite communication links; comprising the following steps:

[0006] (1) Create a circular linked list A with N nodes; where N is a set value;

[0007] (2) Create N cache queues and link them to N nodes in circular linked list A; where each element in the cache queue contains two attributes: service packet and number of rounds to wait for transmission.

[0008] (3) Execute steps (4), (5) and (6) simultaneously;

[0009] (4) Start the thread and use pointer P to poll each node in the circular linked list A at a fixed period of t.

[0010] (5) After receiving the service packet to be transmitted from the satellite communication link, calculate the number of rounds to wait for transmission and the insertion position, and insert the received service packet and the result of the calculation of the number of rounds to wait for transmission into the tail of the buffer queue at the node corresponding to the current position pointed to by pointer P + the insertion position;

[0011] (6) Start another thread. When the position pointed to by pointer P changes, poll all elements in the cache queue pointed to by pointer P. If the current element's round number attribute is 0, send out the business packet in that element; otherwise, decrement the round number of that element by 1.

[0012] In step (5), the number of waiting rounds and the insertion position are calculated as follows: (transmission delay ÷ fixed period t) ÷ number of nodes in the circular linked list N. The quotient of the calculation result is the number of waiting rounds, and the remainder is the insertion position.

[0013] The beneficial effects of this invention are as follows:

[0014] This invention utilizes a circular linked list for periodic judgment and employs multi-threading to accurately send service packets from multiple satellite communication links according to transmission delay, thereby reducing the error between the simulated transmission delay results and the theoretical calculation results. It is suitable for digital simulation of satellite communication links with multiple links and large data volumes. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of a circular linked list, a cache queue, and pointers according to an embodiment of the present invention.

[0016] Figure 2 This is a flowchart illustrating the transmission delay simulation method for satellite communication links according to an embodiment of the present invention. Detailed Implementation

[0017] The present invention will now be described in detail with reference to the accompanying drawings.

[0018] A method for simulating transmission delay in satellite communication links. Figure 1 A schematic diagram of a circular linked list, a cache queue, and pointers is provided. Figure 2 The simulation process for transmission delay is given.

[0019] This method utilizes periodic checks using circular linked lists and employs multi-threading to send service packets from multiple satellite communication links, reducing the error between simulation results and theoretical calculations regarding transmission latency. Specifically, it includes the following steps:

[0020] (1) Create a circular linked list A with N nodes; where N is a set value.

[0021] (2) Create N cache queues and link them to N nodes in circular linked list A; where each element in the cache queue contains two attributes: service packet and number of rounds to wait for sending.

[0022] During implementation, a circular linked list with 128 nodes was created, and each node was linked to a cache queue;

[0023] (3) Execute steps (4), (5) and (6) simultaneously.

[0024] (4) Start the thread and use pointer P to poll each node in the circular linked list A at a fixed period t.

[0025] During implementation, pointer P polls each node in the circular linked list A at a fixed period of 1ms;

[0026] (5) After receiving the service packet to be transmitted from the satellite communication link, calculate the number of rounds to wait for transmission and the insertion position, and insert the received service packet and the result of the calculation of the number of rounds to wait for transmission into the tail of the buffer queue at the node corresponding to the current position pointed to by pointer P + the insertion position;

[0027] The calculation method for the number of sending wait rounds and the insertion position is as follows: (transmission delay ÷ fixed period t) ÷ number of circular linked list nodes N. The quotient of the calculation result is the number of sending wait rounds, and the remainder is the insertion position.

[0028] The service packet to be transmitted is received. The transmission delay of the service packet is 134ms. At this time, the pointer P points to the node at position 10 of the circular linked list. Calculate (134÷1)÷128: the number of rounds to wait is 1, and the insertion position is 6. Therefore, the service packet to be transmitted and the node at position 16 of the circular linked list are linked to the tail of the buffer queue.

[0029] (6) Start another thread. When the position pointed to by pointer P changes, poll all elements in the cache queue pointed to by pointer P. If the current element's round number attribute is 0, send out the business packet in that element; otherwise, decrement the round number of that element by 1.

[0030] When pointer P points to the node at position 16 of the circular linked list, the waiting round count for the service packet to be transmitted is 1, so the waiting round count is decremented by 1 and set to 0; when pointer P points to the node at position 16 of the circular linked list again, the service packet to be transmitted is sent.

[0031] This completes the simulation of transmission delay applicable to satellite communication links.

Claims

1. A method for simulating transmission delay in satellite communication links, characterized in that, Digital simulation for satellite communication links; including the following steps: (1) Create a circular linked list A with N nodes; where N is a set value; (2) Create N cache queues and link them to N nodes in circular linked list A; where each element in the cache queue contains two attributes: service packet and number of rounds to wait for transmission. (3) Execute steps (4), (5) and (6) simultaneously; (4) Start the thread and use pointer P to poll each node in the circular linked list A at a fixed period of t. (5) After receiving the service packet to be transmitted from the satellite communication link, calculate the number of rounds to wait for transmission and the insertion position, and insert the received service packet and the result of the calculation of the number of rounds to wait for transmission into the tail of the buffer queue at the node corresponding to the current position pointed to by pointer P + the insertion position; (6) Start another thread. When the position pointed to by pointer P changes, poll all elements in the cache queue pointed to by pointer P. If the current element's round number attribute is 0, send out the service packet in that element; otherwise, decrement the round number of that element by 1. This completes the simulation of transmission delay applicable to satellite communication links.

2. The transmission delay simulation method for satellite communication links according to claim 1, characterized in that, In step (5), the number of waiting rounds and the insertion position are calculated as follows: (transmission delay ÷ fixed period t) ÷ number of nodes in the circular linked list N. The quotient of the calculation result is the number of waiting rounds, and the remainder is the insertion position.

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