Transmission delay simulation method suitable for satellite communication link

Abstract

The invention discloses a transmission time delay simulation method suitable for a satellite communication link, belongs to the technical field of satellite communication simulation, and aims at solving the problem that in the digital simulation process of a satellite-ground transmission link of a satellite communication system, the error between a transmission time delay simulation result and a theoretical calculation result is too large under the conditions of multiple links and large service data volume. And the service packets of the plurality of satellite communication links are accurately sent according to the transmission time delay by utilizing periodic judgment of a circular linked list and through multiple threads. The method can be applied to transmission delay simulation in digital simulation of satellite communication transmission links under the conditions of multiple links and large service data volume.

Description

Technical Field

[0001] The invention relates to a transmission delay simulation method suitable for a satellite communication link, and belongs to the technical field of satellite communication simulation. Background Art

[0002] In recent years, in order to conduct research on satellite communication related technologies, the simulation technology of satellite communication systems has been continuously developed. For the transmission delay simulation of satellite communication links, many simulation software directly set the service packets received by the communication link to be sent regularly for processing. In the case of multiple links and large business data volume, due to the large number of scheduled tasks and the time required for task processing, it is easy to produce a large error between the simulation results of transmission delay and the theoretical calculation results, which has an adverse effect on other 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, which utilizes periodic judgment of a circular linked list 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 of the transmission delay and the theoretical calculation results.

[0004] In order to achieve the above-mentioned object of the invention, the technical solution adopted by the present invention is:

[0005] A transmission delay simulation method applicable to a satellite communication link is used for digital simulation of a satellite communication link; the method comprises 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 the circular linked list A; each element in the cache queue contains two attributes: a service packet and a waiting round number for sending;

[0008] (3) synchronously executing step (4), step (5) and step (6);

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

[0010] (5) After receiving the service packet to be transmitted on the satellite communication link, the number of waiting rounds for sending and the insertion position are calculated, and the received service packet and the calculation result of the number of waiting rounds for sending are inserted into the tail of the cache 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 round number attribute of the current element is 0, send the business packet in the element. Otherwise, reduce the round number of the element by 1.

[0012] The calculation method for the number of waiting rounds and the insertion position in step (5) is: (transmission delay ÷ fixed period t) ÷ the 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 the present invention are:

[0014] The present invention utilizes the periodic judgment of a circular linked list and uses multi-threading to accurately send the service packets of multiple satellite communication links according to the transmission delay, which can reduce the error between the simulation result and the theoretical calculation result of the transmission delay, and is suitable for the digital simulation of satellite communication links with multi-link large data volumes. BRIEF DESCRIPTION OF THE DRAWINGS

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

[0016] Figure 2 The present invention is a flowchart of a transmission delay simulation method suitable for a satellite communication link according to an embodiment of the present invention. DETAILED DESCRIPTION

[0017] The present invention is described in detail below with reference to the accompanying drawings.

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

[0019] The method utilizes the periodicity judgment of a circular linked list and utilizes multithreading to send service packets of multiple satellite communication links, thereby reducing the error between the simulation result and the theoretical calculation result of the transmission delay; the method specifically comprises 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 the circular linked list A; wherein the elements in each cache queue contain two attributes: a service packet and a number of waiting rounds for sending.

[0022] During the 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] In the implementation, pointer P polls each node in the circular linked list A at a fixed period of 1 ms;

[0026] (5) After receiving the service packet to be transmitted on the satellite communication link, the number of waiting rounds for sending and the insertion position are calculated, and the received service packet and the calculation result of the number of waiting rounds for sending are inserted into the tail of the cache queue at the node corresponding to the current position pointed to by pointer P + the insertion position;

[0027] The calculation method of the number of waiting rounds and the insertion position is: (transmission delay ÷ fixed period t) ÷ the 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.

[0028] A service packet to be transmitted is received, and the transmission delay of the service packet is 134ms. At this time, the pointer P points to the node at position 10 in the circular linked list, and (134÷1)÷128 is calculated: the number of waiting rounds for sending is 1, and the insertion position is 6; therefore, the service packet to be transmitted and the number of waiting rounds 1 are inserted into the tail of the cache queue linked to the node at position 16 in the circular linked list.

[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 round number attribute of the current element is 0, send the business packet in the element. Otherwise, reduce the round number of the element by 1.

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

[0031] At this point, the transmission delay simulation applicable to satellite communication links is completed.

Claims

1. A transmission delay simulation method suitable for satellite communication links, characterized in that: Used for digital simulation of satellite communication links; comprising 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 the circular linked list A; each element in the cache queue contains two attributes: a service packet and a waiting round number for sending; (3) synchronously executing step (4), step (5) and step (6); (4) Start the thread and use pointer P to poll each node in the circular linked list A at a fixed period t; (5) After receiving the service packet to be transmitted on the satellite communication link, the number of waiting rounds for sending and the insertion position are calculated, and the received service packet and the calculation result of the number of waiting rounds for sending are inserted into the tail of the cache 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 round number attribute of the current element is 0, send the service packet in the element. Otherwise, reduce the round number of the element by 1. At this point, the transmission delay simulation applicable to satellite communication links is completed.

2. A transmission delay simulation method suitable for satellite communication links according to claim 1, characterized in that: The calculation method for the number of waiting rounds and the insertion position in step (5) is: (transmission delay ÷ fixed period t) ÷ the 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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