Time-sensitive network periodic service flow single-path redundancy transmission method

Abstract

The invention discloses a single-path redundant transmission method for periodic service flow of a time-sensitive network. The method comprises the following steps: determining network parameters and transmission requirements; calculating the number of redundant windows; establishing a linear shaping constraint condition; establishing a linear shaping multi-objective function; solving the offset of the redundant window; calculating and configuring a redundant window time position; controlling receiving and transmitting time of the data frame; data frame redundancy sending control; and controlling data frame redundancy receiving. According to the method, a plurality of conflict-free transmission windows are planned for each data frame of the periodic service flow of the time-sensitive network in a limited time according to the transmission reliability requirement of the periodic service flow of the time-sensitive network in a wireless or wired network single-path transmission environment, and the data frames are copied to the plurality of windows for transmission, so that the transmission reliability of the periodic service flow of the time-sensitive network is improved. Rapid error recovery of the periodic service flow data frame of the time-sensitive network is realized, and the reliability of service flow end-to-end transmission is improved.

Description

Technical Field

[0001] The present invention belongs to the field of communications, and in particular relates to a single-path redundant transmission method for periodic service flows in a wired or wireless time-sensitive network. Background Art

[0002] In time-sensitive networks, periodic service flows often carry critical control information and place high demands on transmission reliability. Dedicated transmission windows are typically planned to provide reliable end-to-end transmission services for periodic service flows, ensuring that transmission delay and jitter meet requirements. Existing technologies only plan one transmission window for periodic service flows within each cycle of a single path. When an error occurs in a data frame transmitted within a window on the path, the receiving end will not be able to correctly receive the frame, resulting in a transmission failure of the periodic service flow. This problem exists in wireless or wired time-sensitive networks where there is a single transmission path between nodes. In wireless networks, this problem becomes more prominent due to the higher bit error rate of the link.

[0003] Currently, there are two solutions to improve the end-to-end transmission reliability of periodic traffic flows in time-sensitive networks. The first is to use multipath backup transmission. This approach requires establishing at least two redundant transmission links between the source and destination nodes of a time-sensitive traffic flow. Data frames for each period of the periodic traffic flow are simultaneously sent and received on each redundant link. Therefore, as long as each node on the source and destination paths receives a correct data frame, end-to-end reliable transmission is achieved. However, this method requires establishing at least two identical links between the source and destination. It is primarily used in time-sensitive networks in wired environments and significantly increases the number of links required in the network. The second is to adopt the send-response transmission method. This method requires that between the source and destination nodes of the time-sensitive network periodic service flow, a data frame transmission window be planned in the forward transmission direction of each path, and a response frame transmission window corresponding to the frame be planned in the reverse transmission direction. The sender of each path determines whether the corresponding data frame is transmitted correctly by receiving the response frame. If there is a transmission error, the sender resends the transmission error data in the next data frame transmission window. This method requires that each path passed by the source and destination needs to pre-plan multiple paired data frames and response frame windows. Each time a transmission error occurs on any path, the round-trip transmission delay of the path needs to be increased once. Therefore, when more transmission errors occur, the transmission delay will increase significantly, and there is no explanation on how to determine the number of pre-planned data frames and response frame windows on each path. Summary of the Invention

[0004] To improve the reliability of single-path transmission of time-sensitive network periodic services, the present invention proposes a single-path redundant transmission method for time-sensitive network periodic service flows, which specifically includes the following steps:

[0005] Step (1): Determine network parameters and transmission requirements;

[0006] First, various parameters are obtained according to user needs and network environment, and solution variables are set, including: a set of periodic service flows F that need to be redundantly transmitted on a single path, where f i represents the i-th service flow in F, where 1≤i≤FN, FM is the total number of periodic service flows in F, and f i The period is p i , all periodic service flows p in the network i The lowest common multiple of the current network is the super period HP, f i The jth path from the source to the destination in the network is l i，j , 1≤j≤L i , L i f i The total number of paths in the network, f i In l i，j The link transmission delay on the i，j , f i The data frame of each cycle is l i，j The window time occupied is t i，j , f i Each cycle data frame is l i，j The processing delay at the receiving end is pd i，j , f i In l i，j The probability of correctly transmitting a data frame is lr i，j ,0<lr i，j <1, f i The reliability probability requirement on a single path is r i , 0<r i <1, f i The end-to-end transmission delay required for each periodic data frame is td i , f i Each cycle data frame is l i，j The redundancy window time interval corresponding to the sending end is rt i，j , when rt i，j = 0, then at l i，j Only one transmission window needs to be set, f i In l i，j The sender's p i The offset of the kth redundant window relative to the cycle start time is wp i，j，k ;

[0007] Step (2): Calculate the number of redundant windows;

[0008] According to network parameters and transmission requirements, calculate f iIn l i，j The number of redundant transmission windows wn that needs to be planned i，j , where wn i，j To satisfy The minimum integer value under the condition, that is

[0009] Step (3): Establish linear shaping constraints;

[0010] Establish f i In l i，j The linear integer constraint on necessitates the establishment of an end-to-end transmission delay constraint: in Different f in the same link i The transmission window has no conflict constraints: , where p represents the pth business flow, q represents the qth path corresponding to the pth business flow, and m represents f i In the mth cycle of HP, n represents f p In the nth cycle of HP, k represents f i In l i，j The kth redundant window on f, s represents f p In l p,q The sth redundant window on , so fwp i,j,m,k f i In l i,j The mth p in the HP of the sender i The time position values of the k redundant windows within, f i Adjacent link window offset increment constraint: Requirement If wn i,j ≠1, we need to increase f i In l i,j Redundancy window time interval constraints on: Requirements Minimum interval constraint for adjacent redundant windows on the same link: Requirements

[0011] Step (4): Establish a linear shaping multi-objective function;

[0012] Establish a multi-objective function for linear integer solution, objective function 1 is: Objective function 2 is: , by introducing the auxiliary variable redundant window center distance cwp i,j,k , convert the absolute value of objective function 2 into a linear form, where cwp i,j,k Requirements:

[0013]

[0014] Objective function 2 is converted to

[0015] Step (5): solving the redundant window offset;

[0016] Use the multi-objective linear integer solver to solve the problem according to the constraints established in step (3) and the multi-objective function established in step (4). If the solver can obtain a feasible solution, that is, obtain all wp i,j,k , go to step (6), if the solver cannot obtain a feasible solution, report the failure of redundant window planning and terminate the step;

[0017] Step (6): Calculate and configure the redundant window time position;

[0018] According to wp i,j,k The value of l i,j After the transmission and processing delay of the path, calculate f i In l i，j The mth p in the HP of the sender i The time position value fwp of the k redundant windows within i，j，m，k , and corresponds to l in time-sensitive networks i，j The sender configuration fwp i，j，m，k , f i In l i，j The periodic data frame is marked with flag i，j Reset to 0, 2≤j≤L i +1, starts redundant transmission of periodic service flow data frames;

[0019] Step (7): Data frame sending and receiving time control;

[0020] Because f i It is a periodic service flow, so after the network is running, each node starts to send and receive f periodically. i until the network stops running; for any l i，j The receiving and sending ends are currently in the receiving and sending window time to judge, when any l i，j The current time of the sender is equal to fwp i，j，m，k Go to step (8), when any l i，j The current time of the receiving end is equal to ld i，j +fwp i，j，m，k When , go to step (9);

[0021] Step (8): data frame redundant transmission control;

[0022] l i，j The sender is in fwp i，j，m，k Send data frames in the window of the start time;

[0023] Step (8.1): If fwp i，j，m，k Where j=1, the data frame sent is f i The data frame of the current cycle, go to step (8.3), if fwp i，j，m，k If j≠1, go to step (8.2);

[0024] Step (8.2): If flag i，j =0, do not send data frames, and report f i In l i，j If the current cycle data frame sends an error message, go to step (8.3). If flag i,j =1, the data frame sent is f i In l i,j For the data frame saved in the current cycle, go to step (8.3);

[0025] Step (8.3): If k = wn i,j And j≠1, set flag i,j Reset to 0 and go to step (7). If k≠wn i，j Or j=1, go directly to step (7);

[0026] Step (9): data frame redundant reception control;

[0027] l i,j The receiving end receives the i,j +fwp i,j,m,k is the data frame in the window of the starting time;

[0028] Step (9.1): If flag i，j+1 =1, go to step (7), if flag i,j+1 ≠1, go to step (9.2);

[0029] Step (9.2): Check the received data frame. If the received data frame is correct, use the data frame as f i In l i，j The data frames received correctly in the current cycle are saved and the flag i,j+1 Set to 1, go to step (7), if the received data frame is wrong or there is no data frame in the window, go to step (9.3);

[0030] Step (9.3): If k = wn i,j , report f i In l i,j The current cycle data frame receives the wrong information, then go to step (7), if k≠wn i,j , go directly to step (7).

[0031] The present invention plans a certain number of redundant transmission windows on each path according to the transmission reliability requirements, ensuring that the periodic business flow meets the delay, jitter and reliability requirements of end-to-end transmission, and can significantly improve the reliability of the periodic business flow during single-path transmission.

[0032] Compared with the prior art, the present invention has the following advantages:

[0033] (1) The present invention proposes a method for single-path redundant transmission of periodic service flows in time-sensitive network link environments such as wired, wireless, and wired-wireless hybrids. The method adopts a method of planning multiple redundant transmission windows at one time on each path passed by the service flow source and destination. The same data frames are transmitted through the redundant windows. Only one data frame needs to be correctly transmitted on each path to achieve reliable transmission of the service flow from the source to the destination.

[0034] (2) The present invention proposes for the first time a method for determining the number of redundant windows for each periodic flow on each path in a time-sensitive network according to transmission reliability requirements and link transmission characteristics, thereby achieving quantification of the number of redundant windows.

[0035] (3) The present invention proposes for the first time to use a linear integer programming solver in a time-sensitive network to plan the required number of conflict-free redundant windows for each periodic flow at the sending end of each path, and all redundant transmission windows must be planned within a specified time interval. Therefore, compared with the traditional sending and replying transmission method, when a data frame transmission error occurs each time, there is no need to introduce an additional round-trip transmission delay of the corresponding path. Multiple transmissions of the data frame can be completed within the specified time interval. Therefore, the error recovery delay when a data frame error occurs is significantly shorter than the traditional sending and replying transmission method.

[0036] (4) The present invention proposes for the first time to add an objective function that the redundant transmission window tends to be evenly distributed within the redundant window time interval when planning the redundant transmission window of a time-sensitive network, so that the redundant window of each periodic flow on each of its paths is distributed as evenly as possible. When burst errors occur in the channel, the evenly distributed redundant window can improve the ability of the redundant data frame to resist burst errors, thereby significantly improving the reliability of periodic flow transmission. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 The working principle of the single-path redundant transmission method is shown;

[0038] Figure 2 Showing a single path redundant transmission method sending flow chart;

[0039] Figure 3 Shows a single-path redundant transmission method receiving flow chart;

[0040] Figure 4Shows an example of a star network topology. DETAILED DESCRIPTION

[0041] The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0042] The present invention proposes a single-path redundant transmission method for periodic service flows in a time-sensitive network. Figure 1 The basic working principle of the present invention is shown, and the method is specifically as follows.

[0043] Step (1): Determine network parameters and transmission requirements;

[0044] First, various parameters are obtained according to user needs and network environment, and solution variables are set, including: a set of periodic service flows F that need to be redundantly transmitted on a single path, where f i represents the i-th service flow in F, where 1≤i≤FN, FN is the total number of periodic service flows in F, and f i The period is p i , all periodic service flows p in the network i The lowest common multiple of the current network is the super period HP, f i The jth path from the source to the destination in the network is l i，j , 1≤j≤L i , L i f i The total number of paths in the network, f i In l i，j The link transmission delay on the i，j , f i The data frame of each cycle is l i，j The window time occupied is t i,j , f i Each cycle data frame is at t i,j The processing delay at the receiving end is pd i,j , f i In l i，j The probability of correctly transmitting a data frame is lr i，j , 0≤lr i，j ≤1,f i The reliability probability requirement on a single path is r i , 0<r i <1, f i The end-to-end transmission delay required for each periodic data frame is td i , f i Each cycle data frame is l i，j The redundancy window time interval corresponding to the sending end is rt i，j , when rt i，j = 0, then at l i，jOnly one transmission window needs to be set, f i (1≤i≤FN) in l i，j (1≤j≤L i ) The sending end p i The offset of the kth redundant window relative to the cycle start time is wp i，j，k .

[0045] Step (2): Calculate the number of redundant windows;

[0046] According to network parameters and transmission requirements, calculate f i (1≤i≤FN) in l i，j (1≤j≤L i The number of redundant transmission windows wn that needs to be planned i，j , where wn i，j To satisfy The minimum integer value under the condition, that is

[0047] Step (3): Establish linear shaping constraints;

[0048] Establish f i (1≤i≤FN) in l i，j (1≤j≤L i ) requires the establishment of an end-to-end transmission delay constraint: in Different f in the same link i The transmission window has no conflict constraints: , Where p represents the p-th business flow, q represents the q-th path corresponding to the p-th business flow, and m represents f i In the mth cycle of HP, n represents f p In the nth cycle of HP, k represents f i In l i，j The kth redundant window on f, s represents f p In l p，q The sth redundant window on , so fwp i,j,m,k f i In l i，j The mth p in the HP of the sender i The time position values of the k redundant windows within, f i Adjacent link window offset increment constraint: Requirement If wn i,j ≠1(1≤i≤FN,1≤j≤L i ), we also need to increase f i In l i，jRedundancy window time interval constraints on: Requirements Minimum interval constraint for adjacent redundant windows on the same link: Requirements

[0049] Step (4): Establish a linear shaping multi-objective function;

[0050] Establish a multi-objective function for linear integer solution, objective function 1 minimizes f as much as possible under the premise of satisfying all constraints i The end-to-end transmission delay of (1≤i≤FN) is calculated, so the objective function 1 is: Objective function 2 tries to make the redundant window within rt under the premise of satisfying all constraints and objective function 1. i，j Evenly distributed in the middle to avoid adjacent wp due to sudden interference i，j，k Continuous errors improve the reliability of transmission, so the objective function 2 is: Since the objective function 2 is a nonlinear formula, it cannot be directly used as the objective function of the multi-objective linear integer solver. Therefore, the auxiliary variable redundant window center distance cwp is introduced i，j，k , convert the absolute value of objective function 2 into a linear form, where cwp i，j，k Requirements:

[0051]

[0052] Here, by combining the three formulas The absolute value symbol in is converted to a linear expression. Since the value in the absolute value symbol may be positive or negative, when it is positive, if all three formulas are satisfied at the same time, the first two formulas can guarantee the absolute value, and the last formula is a redundant condition. However, when it is negative, if all three formulas are satisfied at the same time, the first and third formulas can guarantee the absolute value, and the second formula is a redundant condition. Therefore, the three formulas can ensure that when the absolute value symbol is positive or negative, cwp i，j，k All take positive values.

[0053] Therefore, the objective function 2 is transformed into

[0054] Step (5): solving the redundant window offset;

[0055] Use a multi-objective linear integer solver (such as Gurobi, CPLEX solver, etc., which are well known to those skilled in the art (these two solvers are relatively well-known solvers)) to solve the problem according to the constraints established in step (3) and the multi-objective function established in step (4). If the solver can obtain a feasible solution, that is, obtain all wp i，j，k , go to step (6), if the solver cannot obtain a feasible solution, report the failure of redundant window planning and terminate the step;

[0056] Step (6): Calculate and configure the redundant window time position;

[0057] According to wp i，j，k The value of l i，j The transmission and processing delay of the previous path (because the wp obtained in step 5) i，j，k is the link l in the network i，j The relative offset of the actual network configuration is l i，j The position of the window needs to adopt the absolute time position, that is, considering l i，j The previous link transmission delay and the fwp after the network node processing delay i,j,m,k ), calculate f i In l i,j The mth p in the HP of the sender i The time position value fwp of the k redundant windows within i,j,m,k (As in step 3 fwp i,j,m,k ), and corresponds to l in time-sensitive networks i,j The sender configuration fwp i,j,m,k , f i (1≤i≤FN) in l i,j (2≤j≤L i +1) periodic data frame available flag i,j Reset to 0, and then start the redundant transmission of periodic service flow data frames;

[0058] Step (7): Data frame sending and receiving time control;

[0059] Because f i It is a periodic service flow, so after the network is running, each node starts to send and receive f periodically. i until the network stops running. i，j (1≤i≤FN,1≤j≤L i ) to determine whether the receiving and sending ends are currently in the receiving and sending window time, such as Figure 2 As shown, when any l i，j The current time of the sender is equal to fwp i，j，m，k When , go to step (8), such as Figure 3 As shown, when any l i，j The current time of the receiving end is equal to ld i，j +fwp i，j，m，k When , go to step (9). Step 7 is mainly to complete Figure 2 and Figure 3 Whether the current system time reaches the receiving or sending window, sending and receiving are executed in parallel. If it reaches the sending window, Figure 2 Execute step 8. If the receiving window is reached, follow Figure 3 Go to step 9.

[0060] Step (8): data frame redundant transmission control;

[0061] like Figure 2 As shown, l i，j The sender is in fwp i，j，m，k Send data frames in the window of the start time;

[0062] Step (8.1): If fwp i，j，m，k Where j=1, the data frame sent is f i The data frame of the current cycle, go to step (8.3), if fwp i,j,m,k If j≠1, go to step (8.2);

[0063] Step (8.2): If flag i,j =0, do not send data frames, and report f i In l i，j If the current cycle data frame sends an error message, go to step (8.3). If flag i，j =1, the data frame sent is f i In l i，j For the data frame saved in the current cycle, go to step (8.3);

[0064] Step (8.3): If k = wn i，j And j≠1, set flag i，j Reset to 0 and go to step (7). If k≠wn i，j Or j=1, go directly to step (7);

[0065] Step (9): data frame redundant reception control;

[0066] like Figure 3 As shown, l i,j The receiving end receives the i,j +fwp i,j,m,k is the data frame in the window of the starting time;

[0067] Step (9.1): If flag i,j+1 =1, go to step (7), if flag i,j+1 ≠1, go to step (9.2);

[0068] Step (9.2): Check the received data frame. If the received data frame is correct, use the data frame as f i In l i，j The data frames received correctly in the current cycle are saved and the flagi，j+1 Set to 1, go to step (7), if the received data frame is wrong or there is no data frame in the window, go to step (9.3);

[0069] Step (9.3): If k = wn i，j , report f i In l i，j The current cycle data frame receives the wrong information, then go to step (7), if k≠wn i，j , go directly to step (7).

[0070] Because f i It is a periodic service flow, so after the network is running, each node starts to send and receive f periodically. i until the network stops running.

[0071] The redundant receiving and sending methods in steps (8) and (9) are f i In l i，j The sending end (i.e. i，j-1 rt of the receiving end) i，j-1 Time will be from wn i,j-1 Each window of the redundant window receives the data frame of the current cycle. As long as a data frame can be received correctly, the flag i，j =1, then you can follow l i，j wp planned by the sender i，j，k , in wn i，j Send the same data frame in the redundant window to achieve f i In l i，j wn of each cycle data frame i，j Redundant backup transmission to ensure f i In each of its i，j The reliability of transmission on the network meets the requirements and makes wp i，j，k Avoid conflicts in rt i，j The network is evenly distributed as much as possible, thus reducing the f caused by link burst errors. i Continuous errors in redundant data frames occur. Specific embodiments

[0073] like Figure 4 As shown, a star network consisting of three end systems (ES1, ES2, ES3) and a bridge (Br) is taken as an example to illustrate the specific implementation method of the present invention.

[0074] Step (1) According to the service flow transmission requirements and network environment, the network periodic service flow attributes are obtained as shown in Table 1 and the network link attributes are shown in Table 2. i，j = frame length / link rate, and since l1,2 and l 2，2 The receiving ends are the destination nodes of f1 and f2 respectively, so there is no need to consider pd 1，2 and pd 2，2 From p1 and p2, we can get HP = 2ms.

[0075] Table 1 Transmission requirements

[0076]

[0077]

[0078] Table 2 Network parameters

[0079]

[0080] Step (2) Calculate f according to the network parameters and transmission requirements in Tables 1 and 2. i (1≤i≤FN) in l i,j (1≤j≤L i The number of redundant transmission windows wn that needs to be planned i,j ,Right now wn i，j The calculation results and actual values are shown in Table 3.

[0081] Table 3 wn i，j Calculation and retrieval of values

[0082] <![CDATA[wn i，j Logo]]> <![CDATA[wn i，j Calculation results]]> <![CDATA[wn i，j Value]]> <![CDATA[wn 1,1 ]]> 1.25 2 <![CDATA[wn 1，2 ]]> 1.25 2 <![CDATA[wn 2，1 ]]> 7.15 8 <![CDATA[wn 2，2 ]]> 1.25 2

[0083] Step (3) Establish f i (1≤i≤2) in l i，j (1≤j≤L i ) linear integer constraint on the end-to-end transmission delay constraint is: td1≤1ms,td2≤2ms, where td1=ld 1，1 +pd 1，1 +rt 1，1 +t 1，1 +wp 1，2，1 +ld 1，2 +rt 1，2 +t 1，2 =wp 1，2，1 +91124ns,td2=ld 2，1 +pd 2，1 +rt 2，1 +t 2，1 +wp 2,2,1 +ld 2,2 +rt 2,2 +t 2,2 =wp 2，2,1 +112148ns

[0084] , so the end-to-end transmission delay constraint requires: wp 1，2，1 ≤908876ns, wp 2，2，1 ≤1887852ns, since f1 and f2 only have l 1，2 and l 2，2 The two links intersect, so different f i The conflict-free transmission window constraint is: , obtain different f in the same link i The transmission window conflict-free constraints are as follows:

[0085] fwp 1，2，0，1 +t 1，2 ≤fwp 2，2，0，1 ∨fwp 1，2，0，1 ≥fwp 2，2，0，1 +t 2，2 (1)

[0086] fwp 1，2，0，2 +t 1，2 ≤fwp 2，2，0，1 ∨fwp 1，2，0，2 ≥fwp 2，2，0，1 +t 2，2 (2)

[0087] fwp 1，2，1，1 +t 1，2 ≤fwp 2，2，0，1 ∨fwp 1，2，1，1 ≥fwp 2，2，0，1 +t 2，2 (3)

[0088] fwp 1，2，1，2 +t 1，2 ≤fwp 2，2，0，1 ∨fwp 1，2，1，2 ≥fwp 2，2，0，1 +t 2，2 (4)

[0089] fwp 1，2，0，1 +t 1，2 ≤fwp 2，2，0，2 ∨fwp 1，2，0，1 ≥fwp 2，2，0，2 +t 2，2 (5)

[0090] fwp 1，2，0，2 +t 1，2 ≤fwp 2，2，0，2 ∨fwp 1，2，0，2 ≥fwp 2，2，0，2 +t 2，2 (6)

[0091] fwp1，2，1，1 +t 1，2 ≤fwp 2，2，0，2 ∨fwp 1，2，1，1 ≥fwp 2，2，0，2 +t 2，2 (7)

[0092] fwp 1，2，1，2 +t 1，2 ≤fwp 2，2，0，2 ∨fwp 1，2，1，2 ≥fwp 2，2，0，2 +t 2，2 (8)

[0093] Also because So fwp 1,2,0,1 =70562ns+wp 1,2,1 ,fwp 1,2,0,2 =70562ns+wp 1,2,2 ,fwp 1，2，1，1 =1070562bs+wp 1，2，1 ,fwp 1，2，1，2 =1070562ns+wp 1，2，2 ,fwp 2，2，0，1 =81074ns+wp 2，2，1 ,fwp 2,2,0,2 =81074ns+wp 2,2,2 , the calculated fwp i，j，m，k and t i，j Substituting into equations (1) to (8) we can get different f in the same link: i The transmission window conflict-free constraints are as follows:

[0094] wp 1，2，1 ≤10000ns+wp 2，2，1 ∨wp 1，2，1 ≥11536ns+wp 2，2，1

[0095] wp 1，2，2 ≤10000ns+wp 2，2，1 ∨wp 1，2，2 ≥11536ns+wp 2，2，1

[0096] 990000ns+wp 1，2，1 ≤wp 2，2，1 ∨988464ns+wp 1，2，1 ≥wp 2，2，1

[0097] 990000ns+wp 1，2，2 ≤wp 2，2，1 ∨988464ns+wp1，2，2 ≥wp 2，2，1

[0098] wp 1，2，1 ≤10000ns+wp 2，2，2 ∨wp 1，2，1 ≥11536ns+wp 2，2，2

[0099] wp 1,2,2 ≤10000ns+wp 2,2,2 ∨wp 1,2,2 ≥11536ns+wp 2,2,2

[0100] 990000ns+wp 1,2,1 ≤wp 2,2,2 ∨988464ns+wp 1,2,1 ≥wp 2,2,2

[0101] 990000ns+wp 1,2,1 ≤wp 2,2,2 ∨988464ns+wp 1,2,1 ≥wp 2,2,2

[0102] f i The incremental constraint of the adjacent link window offset is: wp 1,1,1 ≤wp 1,2,1 , wp 2,1,1 ≤wp 2,2,1 , because wn i，j ≠1(1≤i≤FN,1≤j≤L i ), we also need to increase f i In l i，j The redundancy window time interval constraint on the same link, and the minimum interval constraint of adjacent redundant windows on the same link, f i In l i，j The redundant window time interval constraint on wp is: 1，1，2 -wp 1，1，1 =20000ns, wp 1，2，2 -wp 1，2，1 =20000ns, wp 2，1，8 -wp 2，1，1 =30000ns, wp 2，2，2 -wp 2，2，1 =30000ns, the minimum interval constraint of adjacent redundant windows on the same link is: wp 1，1，1 +t 1，1 ≤wp 1，1，2 , wp 1，2，1 +t 1，2 ≤wp 1，2，2,wp2,1,1+t2,1≤wp2,1,2,wp2,1,2+t2,1≤wp2,1,3,wp2,1,3+t2,1≤wp2,1,4,wp 2，1，4 +t 2，1 ≤wp 2，1，5 , wp 2，1，5 +t 2，1 ≤wp 2，1，6 , wp 2,1,6 +t 2,1 ≤wp 2,1,7 , wp 2,1,7 +t 2,1 ≤wp 2,1,8 , wp 2,2,1 +t 2,2 ≤wp 2,2,2 , t 1，1 and t 1,2 After substituting, the minimum interval constraint of adjacent redundant windows on the same link is obtained as: wp 1,1,1 +512ns≤wp 1,1,2 , wp 1,2,1 +512ns≤wp 1,2,2 , wp 2,1,1 +1024ns≤wp 2,1,2 , wp 2,1,2 +1024ns≤wp 2,1,3 , wp 2,1,3 +1024ns≤wp 2,1,4 , wp 2，1，4 +1024ns≤wp 2，1，5 , wp 2，1，5 +1024ns≤wp 2，1，6 , wp 2，1，6 +1024ns≤wp 2，1，7 , wp 2,1,7 +1024ns≤wp 2,1,8 , wp 2,2,1 +1024ns≤wp 2,2,2 .

[0103] Step (4) establishes a multi-objective function for linear integer solution, objective function 1 is: min(td1+td2), after substituting td1 and td2 and removing the constant term, objective function 1 is: min(wp 1，2， 1+wp 2，2，1 ), objective function 2 is: min(cwp 2，1，2 +cwp 2，1，3 +cwp 2，1，4 +cwp 2，1，5 +cwp 2，1，6 +cwp 2，1，7 ), each cwpi，j，k Converted to a linear form as:

[0104] cwp 2，1，2 ≥0, cwp 2，1，3 ≥0, cwp 2，1，4 ≥0, cwp 2，1，5 ≥0, cwp 2，1，6 ≥0, cwp 2，1，7 ≥0

[0105] cwp 2，1，2 ≥wp 2，1，2 -(wp 2，1，1 +4285ns)

[0106] cwp 2,1,2 ≥-(wp 2,1,2 -(wp 2,1,1 +4285ns))

[0107] cwp 2，1，3 ≥wp 2，1，3 -(wp 2，1，1 +4285ns×2)

[0108] cwp 2，1，3 ≥-(wp 2，1，3 -(wp 2，1，1 +4285ns×2))

[0109] cwp 2，1，4 ≥wp 2，1，4 -(wp 2，1，1 +4285ns×3)

[0110] cwp 2，1，4 ≥-(wp 2，1，4 -(wp 2，1，1 +4285ns×3))

[0111] cwp 2，1，5 ≥wp 2，1，5 -(wp 2，1，1 +4285ns×4)

[0112] cwp 2，1，5 ≥-(wp 2，1，5 -(wp 2，1，1 +4285ns×4))

[0113] cwp 2，1，6 ≥wp 2，1，6 -(wp 2，1，1 +4285ns×5)

[0114] cwp 2，1，6 ≥-(wp 2，1，6 -(wp2，1，1 +4285ns×5))

[0115] cwp 2，1，7 ≥wp 2，1，7 -(wp 2，1，1 +4285ns×6)

[0116] cwp 2，1，7 ≥-(wp 2，1，7 -(wp 2，1，1 +4285ns×6))

[0117] In step (5), a multi-objective linear integer solver (such as Gurobi, CPLEX, etc.) is used to solve the problem according to the constraints and the objective function. In this embodiment, the Gurobi solver is used to obtain a feasible solution. The f1 window planning results are shown in Table 4, and the f2 window planning results are shown in Table 5.

[0118] Table 4 f1 window planning results

[0119] Window logo <![CDATA[wp 1，1，1 ]]> <![CDATA[wp 1，1，2 ]]> <![CDATA[wp 1，2，1 ]]> <![CDATA[wp 1,2,2 ]]> Window value (ns) 0 20000 0 20000

[0120] Table 5 f2 window planning results

[0121] Window logo <![CDATA[wp 2，1，1 ]]> <![CDATA[wp 2，1，2 ]]> <![CDATA[wp 2，1，3 ]]> <![CDATA[wp 2，1，4 ]]> <![CDATA[wp 2，1，5 ]]> <![CDATA[wp 2，1，6 ]]> <![CDATA[wp 2，1，7 ]]> <![CDATA[wp 2，1，8 ]]> <![CDATA[wp 2，2，1 ]]> <![CDATA[wp 2，2，2 ]]> Window value (ns) 0 4285 8570 12855 17140 21425 25710 30000 0 30000

[0122] Step (6) is as follows: i，j，k The value of Get the fwp of f1 and f2 i，j，m，k The values are shown in Table 6 and Table 7 respectively. The corresponding sender configuration fwp in the time-sensitive network i，j，m，k , set flag 1,2 、flag 2,2 、flag 1,3 and flag 2,3 Reset to 0 and then start redundant transmission of periodic service flow.

[0123] Table 6 Time position values of f1 redundant window

[0124] Window logo <![CDATA[fwp 1，1，0，1 ]]> <![CDATA[fwp 1，1，0，2 ]]> <![CDATA[fwp 1，1，1，1 ]]> <![CDATA[fwp 1，1，1，2 ]]> <![CDATA[fwp 1，2，0，1 ]]> <![CDATA[fwp 1，2，0，2 ]]> <![CDATA[fwp 1，2，1，1 ]]> <![CDATA[fwp 1，2，1，2 ]]> Window value (ns) 0 20000 1000000 1002000 70562 90562 1070562 1090562

[0125] Table 7 Time position values of f2 redundant window

[0126]

[0127] Step (7) is to 1，1 and l 1，2 The sending end, l 2，1 and l 2,2The receiving end and the sending end are currently in the receiving and sending window time to judge. 1，1 、l 1，2 、l 2，1 and l 2，2 The sending and receiving ends of multiple links execute steps (8) and (9) simultaneously. 1，1 and l 2，1 The redundant transmission control of data frames corresponds to steps (8-1) and (8-2), respectively. 1，2 and l 2，2 The data frame redundant transmission control corresponds to steps (8-3) and (8-4), respectively. 1，1 and l 2，1 The data frame redundant reception control corresponds to steps (9-1) and (9-2), respectively. 1，2 and l 2，2 The data frame redundant reception control corresponds to steps (9-3) and (9-4) respectively. 1，1 The time of the sender is equal to fwp 1，1，0，1 、fwp 1,1,0,2 、fwp 1,1,1,1 or fwp 1,1,1,2 When f1 is executed, the redundant transmission of the periodic data frame at the source end ES1 is executed, and the process goes to step (8-1); currently l 2，1 The time of the sender is equal to fwp 2，1，0，1 、fwp 2，1，0，2 、fwp 2，1，0，3 、fwp 2，1，0，4 、fwp 2，1，0，5 、fwp 2，1，0，6 、fwp 2，1，0，7 or fwp 2，1，0，8 When f2 is executed, the redundant transmission of periodic data frames at the source end ES2 is executed, and the process goes to step (8-2); currently l 1，1 The time at the receiving end is equal to 50ns+fwp 1，1，0，1 、50ns+fwp 1，1，0，2 、50ns+fwp 1，1，1，1 or 50ns+fwp 1，1，1，2 When executing f1 in l 1，1 The receiving end receives redundant data frames and goes to step (9-1); currently 2，1 The time at the receiving end is equal to 50ns+fwp 2,1,0,1 、50ns+fwp 2,1,0,2 、50ns+fwp 2,1,0,3 、50ns+fwp 2,1,0,4 、50ns+fwp 2,1,0,5 、50ns+fwp 2,1,0,6 、50ns+fwp 2，1，0，7or 50ns+fwp 2，1，0，8 When executing f2 in l 2,1 The data frame of the receiving end is redundantly received, and the process goes to step (9-2); 1,2 The time of the sender is equal to fwp 1，2，0，1 、fwp 1，2，0，2 、fwp 1，2，1，1 or fwp 1，2，1，2 When f1 is executed, redundant data frame transmission is performed in the period of Br, and the process goes to step (8-3); currently l 2，2 The time of the sender is equal to fwp 2，2，0，1 or fwp 2，2，0，2 When f2 is executed, redundant data frames are sent in the period of Br, and the process goes to step (8-4); 1，2 The time at the receiving end is equal to 50ns+fwp 1，2，0，1 、50ns+fwp 1，2，0，2 、50ns+fwp 1，2，1，1 or 50ns+fwp 1，2，1，2 When executing f1 in l 1，2 The receiving end receives the data frame redundantly, and then goes to step (9-3); 2，2 The time at the receiving end is equal to 50ns+fwp 2，2，0，1 or 50ns+fwp 2，2，0，2 When executing f2 in l 2，2 The receiving end receives the data frame redundantly and proceeds to step (9-4);

[0128] Step (8-1) 1 1，1 The sender is in fwp 1，1，0，1 、fwp 1，1，0，2 、fwp 1，1，1，1 or fwp 1，1，1，2 Send data frames in the window of the start time;

[0129] Step (8-1.1) sends the current cycle 64-Byte data frame of data frame f1, and executes step (7) in a loop;

[0130] Step (8-2) 1 2，1 The sender is in fwp 2，1，0，1 、fwp 2，1，0，2 、fwp 2，1，0，3 、fwp 2，1，0，4 、fwp 2，1，0，5 、fwp 2，1，0，6 、fwp 2，1，0，7 or fwp 2，1，0，8 Send data frames in the window of the start time;

[0131] Step (8-2.1) sends the current cycle 128Byte data frame of data frame f2, and executes step (7) in a loop;

[0132] Steps 8 and 9 correspond to the redundant data frame sending and receiving control of a link respectively. Since there are multiple links in the example, multiple links will execute steps (8) and (9) at the same time. Therefore, the subsequent steps are renumbered.

[0133] Step (9-1) 1 1，1 The receiving end receives the signal with 50ns+fwp 1，1，0，1 、50ns+fwp 1，1，0，2 、50ns+fwp 1，1，1，1 or 50ns+fwp 1，1，1，2 The data frame in the window of the start time, the current flag 1，2 ≠1 execute step (9-1.1), current flag 1，2 =1Execute step (9-1.2);

[0134] Step (9-1.1) checks the received 64-Byte data frame of f1. If the received data frame is correct, use the data frame as the data frame of f1 in l 1，1 The data frames received correctly in the current cycle are saved and the flag is set 1，2 Set to 1 and execute step (7) repeatedly;

[0135] Step (9-1.2) loops through step (7);

[0136] Step (9-2) 1 2，1 The receiving end receives the signal with 50ns+fwp 2，1，0，1 、50ns+fwp 2，1，0，2 、50ns+fwp 2，1，0，3 、50ns+fwp 2，1，0，4 、50ns+fwp 2，1，0，5 、50ns+fwp 2,1,0,6 、50ns+fwp 2,1,0,7 or 50ns+fwp 2，1，0，8 The data frame in the window of the start time, the current flag 2，2 ≠1 execute step (9-2.1), current flag 2，2 =1Execute step (9-2.2);

[0137] Step (9-2.1) verifies the received 128Byte data frame of f2, and checks the received 128Byte data frame in 50ns+fwp. 2,1,0,1 or 50ns+fwp 2,1,0,2 The data frame received by the window is wrong, and step (7) is executed in a loop. 2,1,0,3The data received by the window is correct, and the flag 2，2 Set to 1 and execute step (7) repeatedly;

[0138] Step (9-2.2) loops through step (7);

[0139] Step (8-3) 1 1,2 The sender is in fwp 1,2,0,1 、fwp 1,2,0,2 、fwp 1,2,1,1 or fwp 1,2,1,2 Send data frames in the window of the start time;

[0140] Step (8-3.1) because flag 1,2 =1, the data frame sent is f1 at l 1，2 The 64-Byte data frame saved in the current cycle, if the sending window is fwp 1，2，0，2 or fwp 1，2，1，2 When the flag 1，2 Set to 0 and execute step (7) repeatedly;

[0141] Step (8-4) 1 2，2 The sender is in fwp 2，2，0，1 or fwp 2，2，0，2 Send data frames in the window of the start time;

[0142] Step (8-4.1) because flag 2，2 =1, the data frame sent is f2 at l 2，2 The 128-Byte data frame saved in the current cycle, if the sending window is fwp 2，2，0，2 When the flag 2，2 Set to 0 and execute step (7) repeatedly;

[0143] Step (9-3) 1 1，2 The receiving end receives the signal with 50ns+fwp 1，2，0，1 、50ns+fwp 1，2，0，2 、50ns+fwp 1，2，1，1 or 50ns+fwp 1，2，1，2 The data frame in the window of the start time, the current flag 1，3 ≠1 execute step (9-3.1), current flag 1，3 =1Execute step (9-3.2);

[0144] Step (9-3.1) verifies the received 64-byte data frame of f1, 50ns+fwp 1，2，0，1 and 50ns+fwp 1，2，0，2 The received data frames are all wrong and are in 50ns+fwp 1，2，0，2After the window receives the error data frame, because k = 2, it reports f2 at l 1，2 The data frame reception error occurs in the current cycle, and step (7) is executed in a loop;

[0145] Step (9-3.2) loops through step (7);

[0146] Step (9-4) 1 2，2 The receiving end receives the signal with 50ns+fwp 2，2，0，1 or 50ns+fwp 2，2，0，2 The data frame in the window of the start time, the current flag 2，3 ≠1 execute step (9-4.1), current flag 2，3 =1Execute step (9-4.2);

[0147] Step (9-4.1) checks the received 128Byte data frame of f2. If the received data frame is correct, use the data frame as the data frame of f2 in l 2，2 The data frames received correctly in the current cycle are saved and the flag is set 2，3 Set to 1, complete the redundant transmission of the data frame of the current cycle of f2, and loop to execute step (7);

[0148] Step (9-4.2) executes step (7) in a loop.

[0149] A single-path redundant transmission method for periodic traffic flows in time-sensitive networks (TSNs) is presented. This method, in accordance with the transmission reliability requirements of TSNs, plans multiple conflict-free transmission windows for each data frame of a TSN periodic traffic flow within a limited timeframe and copies the data frame into these windows for transmission. This method achieves rapid error recovery for the data frames of TSNs periodic traffic flows, thereby improving the end-to-end transmission reliability of the traffic flows. The method first determines the number of redundant windows required for each link traversed by each TSN periodic traffic flow based on the link reliability indicators and traffic flow transmission reliability requirements. Then, based on the maximum recovery time for each link traversed by the TSN periodic traffic flow and the end-to-end transmission delay requirements for the TSN periodic traffic flow, linear integer constraints and a multi-objective function are established and solved for the multi-window planning. Finally, based on the obtained window planning results, each data frame of the TSN periodic traffic flow is copied into the corresponding multiple windows at the transmitting end of each link and transmitted. At the receiving end, the correct data frames in the multiple windows are received and merged, thereby achieving single-path redundant transmission of TSNs periodic traffic flows.

Claims

1. A single-path redundant transmission method for periodic service flows in a time-sensitive network, characterized in that: The specific steps include: Step (1): Determine network parameters and transmission requirements; First, various parameters are obtained according to user needs and network environment, and solution variables are set, including: a set of periodic service flows F that need to be redundantly transmitted on a single path, where f i represents the i-th service flow in F, where 1≤i≤FN, FN is the total number of periodic service flows in F, and f i The period is p i , all periodic service flows p in the network i The lowest common multiple of the current network is the super period HP, f i The jth path from the source to the destination in the network is l i，j , 1≤j≤L i , L i f i The total number of paths in the network, f i In l i，j The link transmission delay on the i，j , f i The data frame of each cycle is l i，j The window time occupied is t i，j , f i Each cycle data frame is l i，j The processing delay at the receiving end is pd i，j , f i In l i，j The probability of correctly transmitting a data frame is lr i，j ,0<lr i，j <1, f i The reliability probability requirement on a single path is r i , 0<r i <1, f i The end-to-end transmission delay required for each periodic data frame is td i , f i Each cycle data frame is l i，j The redundancy window time interval corresponding to the sending end is rt i，j , when rt i，j = 0, then at l i，j Only one transmission window needs to be set, f i In l i，j The sender's p i The offset of the kth redundant window relative to the cycle start time is wp i，j，k ; Step (2): Calculate the number of redundant windows; According to network parameters and transmission requirements, calculate f i In l i，j The number of redundant transmission windows wn that needs to be planned i，j , where wn i，j To satisfy The minimum integer value under the condition, that is Step (3): Establish linear shaping constraints; Establish f i In l i，j The linear integer constraint on necessitates the establishment of an end-to-end transmission delay constraint: in Different f in the same link i The transmission window has no conflict constraints: ， Where p represents the p-th business flow, m represents the q-th path corresponding to the p-th business flow, and f i In the mth cycle of HP, n represents f p In the nth cycle of HP, k represents f i In l i，j The kth redundant window on f, s represents f p In l p，q The sth redundant window on , so fwp i，j，m，k f i In l i，j The mth p in the HP of the sender i The time position values of the k redundant windows within, f i Adjacent link window offset increment constraint: Requirement If wn i，j ≠1, we need to increase f i In l i，j Redundancy window time interval constraints on: Requirements Minimum interval constraint for adjacent redundant windows on the same link: Requirements Step (4): Establish a linear shaping multi-objective function; Establish a multi-objective function for linear integer solution, objective function 1 is: Objective function 2 is: , By introducing the auxiliary variable redundant window center distance cwp i，j，k , convert the absolute value of objective function 2 into a linear form, where cwp i，j，k Requirements: Objective function 2 is converted to Step (5): solving the redundant window offset; Use the multi-objective linear integer solver to solve the problem according to the constraints established in step (3) and the multi-objective function established in step (4). If the solver can obtain a feasible solution, that is, obtain all wp i，j，k , go to step (6), if the solver cannot obtain a feasible solution, report the failure of redundant window planning and terminate the step; Step (6): Calculate and configure the redundant window time position; According to wp i，j，k The value of l i，j After the transmission and processing delay of the path, calculate f i In l i，j The mth p in the HP of the sender i The time position value fwp of the k redundant windows within i，j，m，k , and corresponds to l in time-sensitive networks i，j The sender configuration fwp i，j，m，k , f i In l i，j The periodic data frame is marked with flag i，j Reset to 0, 2≤j≤L i +1, starts redundant transmission of periodic service flow data frames; Step (7): Data frame sending and receiving time control; Because f i It is a periodic service flow, so after the network is running, each node starts to send and receive f periodically. i until the network stops running; for any l i，j The receiving and sending ends are currently in the receiving and sending window time to judge, when any l i，j The current time of the sender is equal to fwp i，j，m，k Go to step (8), when any l i，j The current time of the receiving end is equal to ld i，j +fwp i，j，m，k When , go to step (9); Step (8): data frame redundant transmission control; l i，j The sender is in fwp i，j，m，k Send data frames in the window of the start time; Step (8.1): If fwp i，j，m，k Where j=1, the data frame sent is f i The data frame of the current cycle, go to step (8.3), if fwp i，j，m，k If j≠1, go to step (8.2); Step (8.2): If flag i，j =0, do not send data frames, and report f i In l i，j If the current cycle data frame sends an error message, go to step (8.3). If flag i，j =1, the data frame sent is f i In l i，j For the data frame saved in the current cycle, go to step (8.3); Step (8.3): If k = wn i，j And j≠1, set flag i，j Reset to 0 and go to step (7). If k≠wn i，j Or j=1, go directly to step (7); Step (9): data frame redundant reception control; l i，j The receiving end receives the i，j +fwp i，j，m，k is the data frame in the window of the starting time; Step (9.1): If flag i，j+1 =1, go to step (7), if flag i，j+1 ≠1, go to step (9.2); Step (9.2): Check the received data frame. If the received data frame is correct, use the data frame as f i In l i，j The data frames received correctly in the current cycle are saved and the flag i，j+1 Set to 1, go to step (7), if the received data frame is wrong or there is no data frame in the window, go to step (9.3); Step (9.3): If k = wn i，j , report f i In l i，j The current cycle data frame receives the wrong information, then go to step (7), if k≠wn i，j , go directly to step (7).

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