CN112291824A - Wireless video low-delay transmission method in 5G network - Google Patents

Abstract

The invention relates to a low-delay transmission method of a wireless video in a 5G network. The method combines wireless network switching with code rate adjustment of real-time video transmission, acquires 5G signal quality sequences at different acquisition moments through a built-in wireless communication module in the terminal moving process, constructs a linear model of the 5G signal quality sequences, judges the trend of the 5G signal quality sequences along with time change by combining the correlation coefficient of the time sequences of the 5G signal quality and the slope of the linear model of the 5G signal quality sequences to predict network switching points, starting the coding parameter switching judgment of the wireless video terminal before the network link is not switched, predicting the possible change of the channel in advance to adjust the video coding rate, the method and the device adjust the data volume of video data transmission, prepare before network signal switching, achieve stable switching, solve the problems of video blockage and high time delay under the condition of ensuring high definition of video as far as possible, and improve the video data transmission performance.

Description

Wireless video low-delay transmission method in 5G network

Technical Field

The invention belongs to the technical field of 5G video transmission, and particularly relates to a low-delay wireless video transmission method in a 5G network.

Background

The development of communication technology has promoted the rise of wireless video monitoring technology, the progress of 4G and 5G network technology has also made streaming media technology become more and more important, people have made higher requirements on video data transmission, especially the emergence of 5G network, which provides possibility for high-rate communication, but there are two networking schemes at present, NSA (non-independent networking) and SA (independent networking), which are obviously different. Under NSA networking, the 5G base station utilizes the existing 4G core network, the construction of the 5G core network is omitted, the early-stage laying speed is high, the cost is low, the SA needs to build an independent base station, and the time cost required for realizing large-scale coverage is higher, so that NSA networking is a networking mode selected by most operators at the initial stage of 5G network construction. The NSA is a networking mode of fusion of a 4G network and a 5G network, the NSA does not need to build a 5G new core network, and the NSA needs to use a 4G wireless air interface (NSA wireless anchor point is at 4G), but the existing 4G core network architecture and the 4G air interface can not meet the requirements of 5G on time delay and transmission reliability, the 5GNR application frequency band is higher, the coverage range is smaller, and the density of the existing 4G network can not meet the 5G coverage. Therefore, when the wireless vehicle-mounted video terminal is switched between the main node 4G base stations in the moving process under the existing 5G NAS networking network environment, because the adjacent 5G cells belonging to different 4G main nodes cannot be directly switched, the 5G NR resource at the side of the source 4G base station needs to be released firstly, then the switching between the source 4G base station and the target 4G base station is executed, and the 5G NR resource is added to the target 4G base station after the switching is finished, so that the process takes longer time, network switching is frequently carried out, switching delay is caused, the network bandwidth is changed greatly, high-delay and other effects are caused to real-time video transmission, and the effects caused by network vertical switching cannot be eliminated by singly depending on the optimization of a video stream and a data transmission scheme. The invention provides a network switching method under the environment of a 5G NAS networking network by combining the characteristics of wireless network switching and real-time video output to realize stable switching of real-time video transmission code rate of a video terminal in the moving process, reduce code rate fluctuation and solve the problem of high video blocking delay.

In addition, a low-delay and high-reliability video transmission method for a 5G network is provided in the prior art. At present, most methods only encode video data in a single way and adjust the data transmission reliability of channel data, and the method can only reduce the blocking control delay by performing smoothing treatment after the channel transmission changes, and can not predict possible channel changes, and once the transmission rate of a network vertical switching channel is changed greatly, the blocking problem can not be solved.

Disclosure of Invention

The technical problem to be solved by the invention is as follows: the method improves the problems of instable real-time video transmission and high delay caused by frequent network switching of a high-definition video real-time monitoring terminal in the moving process under the current 5G NAS networking environment. The method combines wireless network switching with code rate adjustment of real-time video transmission, predicts a network switching point according to the link quality of the current service network in the terminal moving process, adjusts the video data transmission data volume before the network link is not switched, achieves stable switching, solves the problems of video blockage and high time delay under the condition of ensuring high video definition as much as possible, and improves the video data transmission performance.

A low-delay transmission method of wireless video under a 5G network is characterized by comprising the following steps:

step 1: starting up the initialized video coding parameters of the wireless video terminal to be low quality, connecting the wireless video terminal with a wireless network, and starting to transmit video data;

step 2: the wireless video terminal collects the moving speed at different collection moments through a built-in positioning module and collects the quality of 5G signals at different collection moments through a built-in wireless communication module;

and step 3: the wireless video terminal compares the quality of the 5G signals at different acquisition moments with a trigger network switching threshold value in sequence, and sets video coding parameters to be a low-quality minimum value if the quality of the 5G signals at the acquisition moments is less than the trigger network switching threshold value; if the 5G signal quality at the acquisition moment is greater than the threshold value for triggering network switching, further combining distance threshold value judgment, and if the moving distance of the wireless video terminal is greater than the distance threshold value, further combining signal quality sequence intervals to construct a plurality of 5G signal quality sequences;

and 4, step 4: calculating a correlation coefficient of the time sequence of the 5G signal quality, and further judging whether the fitting is successful or not by combining a correlation coefficient threshold;

step 6: if the fitting is successful, a linear model of the 5G signal quality sequence is constructed, and the trend of the 5G signal quality sequence changing along with the time is judged by combining the correlation coefficient of the time sequence of the 5G signal quality and the slope of the linear model of the 5G signal quality sequence;

and 7: judging whether the two continuous 5G signal quality sequences are successfully fitted according to the correlation coefficient of the time sequences of the two continuous 5G signal qualities, and judging the trend of the two continuous 5G signal quality sequences changing along with the time according to the slope of the linear models of the two continuous 5G signal quality sequences if the two continuous 5G signal quality sequences are successfully fitted; when the slopes of the linear models of the two continuous 5G signal quality sequences are both smaller than a slope judgment threshold, and the minimum value of the signal quality of the two continuous 5G signal quality sequences is smaller than the signal quality threshold, starting the switching judgment of the encoding parameters of the wireless video terminal, and setting the video encoding parameters of the wireless video terminal to be the minimum value of low quality;

preferably, in step 2, the moving speed at different times is:

V₁,V₂,...,V_N

wherein, V_tRepresents the moving speed at the t-th acquisition time, t ∈ [1, N]N is the number of acquisition moments;

and 2, the quality of the 5G signals at different moments is as follows:

Q₁,Q₂,...,Q_N

wherein Q is_tRepresents the 5G signal quality at the tth acquisition time, t ∈ [1, N]N is the number of acquisition moments;

preferably, the threshold value for triggering network handover in step 3 is QRSS _ T;

step 3, if the moving distance of the wireless video terminal is greater than the distance threshold value, the step is as follows:

S_m＞K

wherein S is_mThe moving distance of the wireless video terminal at the mth acquisition moment, namely the moment when the 5G signal quality at the acquisition moment is greater than the threshold value for triggering network switching, K is a distance threshold value, and V is_tRepresenting the moving speed of the t-th acquisition moment;

step 3, the signal quality sequence interval is L;

step 3, constructing a plurality of 5G signal quality sequences as follows:

A＝mod[m/L]

B＝m％L

wherein mod [ m/L ] represents an integer part taking m/L, and m% represents a remainder part taking m/L;

the ith 5G signal quality sequence is:

QL_i＝{Q_i,1,Q_i,2,...,Q_i,j}

i∈[1,A]

wherein Q is_i,jRepresents the jth 5G signal quality in the ith 5G signal quality sequence, j ∈ [1, L]；

The A +1 th 5G signal quality sequence is as follows:

QL_A+1＝{Q_A+1,1,Q_A+1,2,...,Q_A+1,B}

wherein Q is_A+1,wRepresents the w-th 5G signal quality in the A + 1-th 5G signal quality sequence, w epsilon [1, B]；

QL₁,QL₂,,...,QL_A+1The A +1 5G signal quality sequences in the step 3;

preferably, the step 4 of calculating the correlation coefficient of the time series of 5G signal quality is:

wherein Q is_i,jRepresents the jth 5G signal quality in the ith 5G signal quality sequence, j ∈ [1, L]L is the signal quality sequence interval in the step 3, and T is the time point of the acquisition time of acquiring 5G signal quality;

the time sequence corresponding to the ith 5G signal quality sequence is as follows:

TL_i＝{T_i,1,T_i,2,...,T_i,j}

i∈[1,A]

wherein, T_i,jRepresents the time point of the jth 5G signal quality acquisition time in the ith 5G signal quality sequence, j is equal to [1, L ∈]；

μ_TThe average value of the time series corresponding to the ith 5G signal quality series is obtained;

μ_Qis the average of the ith 5G signal quality sequence;

δ_Tthe standard deviation of the time series corresponding to the ith 5G signal quality series;

δ_Qis the standard deviation of the ith 5G signal quality sequence;

r_ia correlation coefficient indicating a time series corresponding to the ith 5G signal quality series and the ith 5G signal quality series;

according to the correlation coefficient r_iSolving whether the sequence is successfully fitted;

when r_i|<c is then TL_i、QL_iThe larger the divergence is, the smaller the data correlation is, and the fitting is considered unsuccessful and is a correlation coefficient threshold;

when r_i|>c is then TL_i、QL_iThe fit was considered successful;

|r_ithe relation between the value of | and the degree of correlation

And 5: if the fitting is unsuccessful, adjusting the code rate of the video coding according to the mean value of the 5G signal quality sequence;

preferably, step 5 adjusts the video coding rate according to the mean value of the 5G signal quality sequence, and the formula is as follows:

BitRate_i＝(μ_Q/((QRSS_MAX)-(QRSS_T)))*(BitRate_MAX-BitRate_MIN)+BitRate_MIN；

wherein, Bitrate_iAdjusting the current video bitrate, mu, for the ith 5G signal quality sequence_QThe mean value of the ith 5G signal quality sequence is defined, QRSS _ MAX is the maximum value of network signal quality, QRSS _ T is the threshold value of network switching signal quality, BitRate _ MIN is the minimum value of code rate, and BitRate _ MAX is the maximum value of code rate;

preferably, the step 6 of constructing a linear model of the 5G signal quality sequence is:

TL_i＝k_i QL_i+b_i

wherein k is_iSlope of a linear model for the ith 5G signal quality sequence, b_iFor the axis intercept of the ith 5G signal quality sequence, A_iFirst coefficient of linear model of ith 5G signal quality sequence，B_iSecond coefficient of linear model of i-th 5G signal quality sequence, C_iThird coefficient of linear model of i-th 5G signal quality sequence, D_iA fourth coefficient that is a linear model of the ith 5G signal quality sequence;

step 4, the ith 5G signal quality sequence is as follows:

QL_i＝{Q_i,1,Q_i,2,...,Q_i,j}

wherein T is the time point of the acquisition time of acquiring the 5G signal quality, and the ith 5G signal quality sequence QL_iThe corresponding time T sequence is:

TL_i＝{T_i,1,T_i,2,...,T_i,j}

i∈[1,A]

wherein A is the number of 5G signal quality sequences, T_i,jRepresents the time point of the jth 5G signal quality acquisition time in the ith 5G signal quality sequence, j is equal to [1, L ∈]；

And 6, judging the time variation trend of the 5G signal quality sequence:

when r_i|>c and r_i<At 0, k_iIf < 0, it indicates that the data is negatively correlated, i.e. when T is_i,jAt increasing time Q_i,jDecreasing, as a correlation coefficient threshold;

when r_i|>c and r_i>At 0, k_iWhen the ratio is more than 0, the data are positively correlated, namely when T is_i,jAt increasing time Q_i,jIncreasing;

preferably, the step 7 of judging whether the two consecutive 5G signal quality sequences are successfully fitted according to the correlation coefficient of the two consecutive 5G signal quality time sequences is as follows:

the two continuous 5G signal quality sequences are as follows: QL_i，QL_i+1；

The correlation coefficients corresponding to the two consecutive 5G signal quality sequences are: r is_i，r_i+1；

|r_i|>c and | r_i+1|>c two consecutive 5G signal quality sequences QL_i，QL_i+1Successful fitting, as a correlationA number threshold;

i belongs to [1, A ], A is the number of 5G signal quality sequences;

and 7, judging the trend of the two continuous 5G signal quality sequences along with the change of time by the slope of the linear models of the two continuous 5G signal quality sequences as follows:

the slopes corresponding to the two consecutive 5G signal quality sequences are: k is a radical of_i，k_i+1；

k_i<K _ T and K_i+1<K _ T, wherein the slopes corresponding to two continuous 5G signal quality sequences are smaller than a slope judgment threshold, and the K _ T is the slope judgment threshold;

step 7, Q _ MIN is the minimum value of the signal quality of the two continuous 5G signal quality sequences_i,Q_MIN_i+1；

Q _ MIN, the minimum value of the signal quality of the ith 5G signal quality sequence_iThe specific calculation method is in QL_iSearching for the minimum value;

q _ MIN, which is the minimum value of signal qualities of the (i + 1) th 5G signal quality series_i+1The specific calculation method is in QL_i+1Searching for the minimum value;

Q_MIN_i<QRSS _ C and Q _ MIN_i+1<QRSS_C

QRSS_C＝(QRSS_MAX-QRSS_T)*0.5+QRSS_T；

Wherein, QRSS _ C is a signal quality threshold, QRSS _ MAX is a maximum network signal quality, and QRSS _ T is a threshold for network handover signal quality.

The invention has the advantages that the video coding code rate is adjusted by predicting the possible change of the channel in advance through sampling of the wireless network signal quality, preparation is made before network signal switching, stable switching is realized, and the problems of video blockage and high time delay are solved.

Drawings

FIG. 1: is a schematic diagram of NSA networking.

FIG. 2: is a schematic diagram of terminal network connection under NSA networking.

FIG. 3: is a schematic flow chart of the method.

Detailed Description

NSA networking 5G network connection and switching process:

under 5G NSA networking, the 5G NR control plane is anchored to 4G and follows the 4G core network EPC, and this architecture is called EN-DC, namely EUTRA-NR dual connectivity architecture.

As shown in fig. 1, in an NSA networking, a 4G base station (eNB) is a Master Node (Master Node), and a 5G base station (gNB) is a Secondary Node (Secondary Node).

As shown in fig. 2, in the user plane, that is, when data traffic is transmitted, both the 4G base station and the 5G base station are directly connected to a network element S-GW of the 4G core network; however, in the control plane, that is, when signaling interaction is performed for data transmission, only the 4G base station is directly connected to the 4G core network element MME. When the terminal wants to transmit high-speed data through the 5G base station, the terminal needs to be connected with the 4G base station for signaling interaction, and the terminal can enjoy the 5G high-speed network only after the 4G base station allocates 5G wireless resources.

Under the NSA networking, that is, EN-DC dual connectivity, a terminal firstly registers in a 4G network, and then reports measured 5G signal strength and quality, etc., for example, when the terminal moves to a coverage area of a 5G cell, it is detected that the 5G signal strength and quality are sufficient to support a 5G service, and then the 4G base station communicates with the 5G base station to allocate 5G resources to a mobile phone. Next, the 4G base station notifies the mobile phone of the resources allocated by the 5G NR through an RRC Connection Reconfiguration (RRC Connection Reconfiguration) message, and after the RRC Connection Reconfiguration process is completed, the mobile phone is connected to the 4G and 5G networks at the same time. The EN-DC dual connection significantly increases the complexity of the signaling flow, and the NR RRC Reconfiguration message that could be directly sent to the terminal needs to be encapsulated and forwarded through 4G multiple times.

When the user moves and the switching between the master node 4G base stations occurs, because the direct switching between the 5G adjacent cells belonging to different 4G master nodes can not be carried out, the 5G NR resource at the side of the source 4G base station needs to be released firstly, then the switching between the source 4G base station and the target 4G base station is carried out, and the 5G NR resource is added to the target 4G base station after the switching is finished, so that the double-connection architecture greatly increases the complexity of the wireless access network signaling, which causes the overlarge switching time delay of the 4G LTE and the 5G NR. The video transmission of the wireless video terminal in the moving process is necessarily influenced by network switching, and the problems of video blockage and high time delay occur.

The following describes the embodiments of the present invention with reference to fig. 1 to 3:

step 1: the method comprises the steps that a wireless video terminal is started to initialize video coding parameters to be low quality, namely a video resolution ratio 1080P code rate 1000kbps is used, a wireless network is registered, and under the EN-DC dual connection of an NSA (non-subsampled network) networking, the terminal firstly registers a 4G LTE (long term evolution) network and starts to transmit video data.

Step 2: the wireless video terminal collects the moving speed at different collection moments through a built-in positioning module and collects the quality of 5G signals at different collection moments through a built-in wireless communication module;

and 2, the moving speeds at different moments are as follows:

V₁,V₂,...,V_N

wherein, V_tRepresents the moving speed at the t-th acquisition time, t ∈ [1, N]N is the number of acquisition moments, and N is 15;

and 2, the quality of the 5G signals at different moments is as follows:

Q₁,Q₂,...,Q_N

wherein Q is_tRepresents the 5G signal quality at the tth acquisition time, t ∈ [1, N]N is the number of acquisition moments, and N is 15;

and step 3: the wireless video terminal compares the quality of the 5G signals at different acquisition moments with a trigger network switching threshold value in sequence, and sets video coding parameters to be a low-quality minimum value if the quality of the 5G signals at the acquisition moments is less than the trigger network switching threshold value; if the 5G signal quality at the acquisition moment is greater than the threshold value for triggering network switching, further combining distance threshold value judgment, and if the moving distance of the wireless video terminal is greater than the distance threshold value, further combining signal quality sequence intervals to construct a plurality of 5G signal quality sequences;

step 3, the threshold value for triggering network switching is QRSS _ T, and QRSS _ T is 20;

step 3, if the moving distance of the wireless video terminal is greater than the distance threshold value, the step is as follows:

S_m＞K

wherein S is_mThe moving distance of the wireless video terminal at the mth acquisition moment is the moment when the 5G signal quality at the acquisition moment is greater than the threshold value for triggering network switching, K is 100 meters and is used as a distance threshold value, V_tRepresenting the moving speed of the t-th acquisition moment;

the signal quality sequence interval in the step 3 is L, and L < ═ 15;

step 3, constructing a plurality of 5G signal quality sequences as follows:

A＝mod[m/L]

B＝m％L

wherein mod [ m/L ] represents an integer part taking m/L, and m% represents a remainder part taking m/L;

the ith 5G signal quality sequence is:

QL_i＝{Q_i,1,Q_i,2,...,Q_i,j}

i∈[1,A]

wherein Q is_i,jRepresents the jth 5G signal quality in the ith 5G signal quality sequence, j ∈ [1, L],L<＝15；

The A +1 th 5G signal quality sequence is as follows:

QL_A+1＝{Q_A+1,1,Q_A+1,2,...,Q_A+1,B}

wherein Q is_A+1,wRepresents the w-th 5G signal quality in the A + 1-th 5G signal quality sequence, w epsilon [1, B],B<＝15；

QL₁,QL₂,,...,QL_A+1The A +1 5G signal quality sequences in the step 3;

and 4, step 4: calculating a correlation coefficient of the time sequence of the 5G signal quality, and further judging whether the fitting is successful or not by combining a correlation coefficient threshold;

and 4, calculating the correlation coefficient of the time series of the 5G signal quality as follows:

wherein Q is_i,jRepresents the jth 5G signal quality in the ith 5G signal quality sequence, j ∈ [1, L]L is the signal quality sequence interval in the step 3, and T is the time point of the acquisition time of acquiring 5G signal quality;

the time sequence corresponding to the ith 5G signal quality sequence is as follows:

TL_i＝{T_i,1,T_i,2,...,T_i,j}

i∈[1,A]

wherein, T_i,jRepresents the time point of the jth 5G signal quality acquisition time in the ith 5G signal quality sequence, j is equal to [1, L ∈]；

μ_TThe average value of the time series corresponding to the ith 5G signal quality series is obtained;

μ_Qis the average of the ith 5G signal quality sequence;

δ_Tthe standard deviation of the time series corresponding to the ith 5G signal quality series;

δ_Qis the standard deviation of the ith 5G signal quality sequence;

r_ia correlation coefficient indicating a time series corresponding to the ith 5G signal quality series and the ith 5G signal quality series;

according to the correlation coefficient r_iSolving whether the sequence is successfully fitted;

when r_i|<c is then TL_i、QL_iThe larger the divergence is, the smaller the data correlation is, the fitting is considered unsuccessful, and c is 0.4 which is a correlation coefficient threshold;

when r_i|>c is then TL_i、QL_iThe fit was considered successful;

|r_ithe relationship between the value of | and the degree of correlation is shown in table 1:

table 1: relational table of degree of correlation

|riValue range of |	|riMeaning of |
		0.00-0.19	Extremely low correlation
0.20-0.39	Low degree of correlation
		0.40-0.69	Moderate correlation
0.70-0.89	Correlation of altitude
		0.90-1.00	Extremely high correlation

And 5: if the fitting is unsuccessful, adjusting the code rate of the video coding according to the mean value of the 5G signal quality sequence;

and adjusting the code rate of video coding according to the mean value of the 5G signal quality sequence, wherein the formula is as follows: bitrate_i＝(μ_Q/((QRSS_MAX)-(QRSS_T)))*(BitRate_MAX-BitRate_MIN)+BitRate_MIN；

Wherein, Bitrate_iAdjusting the current video bitrate, mu, for the ith 5G signal quality sequence_QTaking the average value of the ith 5G signal quality sequence, setting QRSS _ MAX as 99 as the maximum value of network signal quality, setting QRSS _ T as 20 as the threshold value of network switching signal quality, setting BitRate _ MIN as the minimum value of code rate, and setting BitRate _ MAX as the maximum value of code rate;

BitRate_MIN＝1000kbps，BitRate_MAX＝6000kbps；

step 6: if the fitting is successful, a linear model of the 5G signal quality sequence is constructed, and the trend of the 5G signal quality sequence changing along with the time is judged by combining the correlation coefficient of the time sequence of the 5G signal quality and the slope of the linear model of the 5G signal quality sequence;

and 6, constructing a linear model of the 5G signal quality sequence as follows:

TL_i＝k_i QL_i+b_i

wherein k is_iSlope of a linear model for the ith 5G signal quality sequence, b_iFor the axis intercept of the ith 5G signal quality sequence, A_iFirst coefficient of linear model of i 5G signal quality sequence, B_iSecond coefficient of linear model of i-th 5G signal quality sequence, C_iThird coefficient of linear model of i-th 5G signal quality sequence, D_iA fourth coefficient that is a linear model of the ith 5G signal quality sequence;

step 4, the ith 5G signal quality sequence is as follows:

QL_i＝{Q_i,1,Q_i,2,...,Q_i,j}

wherein T isTime point of acquisition time for acquiring 5G signal quality, i-th 5G signal quality sequence QL_iThe corresponding time T sequence is:

TL_i＝{T_i,1,T_i,2,...,T_i,j}

i∈[1,A]

wherein A is the number of 5G signal quality sequences, T_i,jRepresents the time point of the jth 5G signal quality acquisition time in the ith 5G signal quality sequence, j is equal to [1, L ∈]；

And 6, judging the time variation trend of the 5G signal quality sequence:

when r_i|>c and r_i<At 0, k_iIf < 0, it indicates that the data is negatively correlated, i.e. when T is_i,jAt increasing time Q_i,jDecreasing, where c is 0.4 is the correlation coefficient threshold;

when r_i|>c and r_i>At 0, k_iWhen the ratio is more than 0, the data are positively correlated, namely when T is_i,jAt increasing time Q_i,jIncreasing;

and 7: judging whether the two continuous 5G signal quality sequences are successfully fitted according to the correlation coefficient of the time sequences of the two continuous 5G signal qualities, and judging the trend of the two continuous 5G signal quality sequences changing along with the time according to the slope of the linear models of the two continuous 5G signal quality sequences if the two continuous 5G signal quality sequences are successfully fitted; when the slopes of the linear models of the two continuous 5G signal quality sequences are both smaller than a slope judgment threshold, and the minimum value of the signal quality of the two continuous 5G signal quality sequences is smaller than the signal quality threshold, starting the switching judgment of the encoding parameters of the wireless video terminal, and setting the video encoding parameters of the wireless video terminal to be the minimum value of low quality;

and 7, judging whether the two continuous 5G signal quality sequences are successfully fitted according to the correlation coefficients of the two continuous 5G signal quality time sequences:

the two continuous 5G signal quality sequences are as follows: QL_i，QL_i+1；

The correlation coefficients corresponding to the two consecutive 5G signal quality sequences are: r is_i，r_i+1；

|r_i|>c and | r_i+1|>c two consecutive 5G signal quality sequences QL_i，QL_i+1The fitting is successful, and c is 0.4, namely a correlation coefficient threshold value;

i belongs to [1, A ], A is the number of 5G signal quality sequences;

and 7, judging the trend of the two continuous 5G signal quality sequences along with the change of time by the slope of the linear models of the two continuous 5G signal quality sequences as follows:

the slopes corresponding to the two consecutive 5G signal quality sequences are: k is a radical of_i，k_i+1；

k_i<K _ T and K_i+1<K _ T, the slopes corresponding to two consecutive 5G signal quality sequences are both smaller than a slope determination threshold, where K _ T ═ tan10 is the slope determination threshold;

step 7, Q _ MIN is the minimum value of the signal quality of the two continuous 5G signal quality sequences_i,Q_MIN_i+1；

Q _ MIN, the minimum value of the signal quality of the ith 5G signal quality sequence_iThe specific calculation method is in QL_iSearching for the minimum value;

q _ MIN, which is the minimum value of signal qualities of the (i + 1) th 5G signal quality series_i+1The specific calculation method is in QL_i+1Searching for the minimum value;

Q_MIN_i<QRSS _ C and Q _ MIN_i+1<QRSS_C

QRSS_C＝(QRSS_MAX-QRSS_T)*0.5+QRSS_T；

Wherein, QRSS _ C is the signal quality threshold, QRSS _ MAX is 99 which is the maximum network signal quality, and QRSS _ T is 20 which is the network handover signal quality threshold.

It should be understood that parts of the specification not set forth in detail are well within the prior art.

It should be understood that the above description of the preferred embodiments is given for clarity and not for any purpose of limitation, and that various changes, substitutions and alterations can be made herein without departing from the spirit and scope of the invention as defined by the appended claims.

Claims (7)

1. A low-delay transmission method of wireless video under a 5G network is characterized in that:

step 1: starting up the initialized video coding parameters of the wireless video terminal to be low quality, connecting the wireless video terminal with a wireless network, and starting to transmit video data;

step 2: the wireless video terminal collects the moving speed at different collection moments through a built-in positioning module and collects the quality of 5G signals at different collection moments through a built-in wireless communication module;

and step 3: the wireless video terminal compares the quality of the 5G signals at different acquisition moments with a trigger network switching threshold value in sequence, and sets video coding parameters to be a low-quality minimum value if the quality of the 5G signals at the acquisition moments is less than the trigger network switching threshold value; if the 5G signal quality at the acquisition moment is greater than the threshold value for triggering network switching, further combining distance threshold value judgment, and if the moving distance of the wireless video terminal is greater than the distance threshold value, further combining signal quality sequence intervals to construct a plurality of 5G signal quality sequences;

and 4, step 4: calculating a correlation coefficient of the time sequence of the 5G signal quality, and further judging whether the fitting is successful or not by combining a correlation coefficient threshold;

step 6: if the fitting is successful, a linear model of the 5G signal quality sequence is constructed, and the trend of the 5G signal quality sequence changing along with the time is judged by combining the correlation coefficient of the time sequence of the 5G signal quality and the slope of the linear model of the 5G signal quality sequence;

and 7: judging whether the two continuous 5G signal quality sequences are successfully fitted according to the correlation coefficient of the time sequences of the two continuous 5G signal qualities, and judging the trend of the two continuous 5G signal quality sequences changing along with the time according to the slope of the linear models of the two continuous 5G signal quality sequences if the two continuous 5G signal quality sequences are successfully fitted; and when the slopes of the linear models of the two continuous 5G signal quality sequences are both smaller than the slope judgment threshold, and the minimum value of the signal quality of the two continuous 5G signal quality sequences is smaller than the signal quality threshold, starting the switching judgment of the encoding parameters of the wireless video terminal, and setting the video encoding parameters of the wireless video terminal to be the minimum value of low quality.

2. The method for wireless video low-latency transmission under a 5G network according to claim 1, wherein:

and 2, the moving speeds at different moments are as follows:

V₁,V₂,...,V_N

wherein, V_tRepresents the moving speed at the t-th acquisition time, t ∈ [1, N]N is the number of acquisition moments;

and 2, the quality of the 5G signals at different moments is as follows:

Q₁,Q₂,...,Q_N

wherein Q is_tRepresents the 5G signal quality at the tth acquisition time, t ∈ [1, N]And N is the number of acquisition moments.

3. The method for wireless video low-latency transmission under a 5G network according to claim 1, wherein:

step 3, the threshold value for triggering network switching is QRSS _ T;

step 3, if the moving distance of the wireless video terminal is greater than the distance threshold value, the step is as follows:

S_m＞K

wherein S is_mThe moving distance of the wireless video terminal at the mth acquisition moment, namely the moment when the 5G signal quality at the acquisition moment is greater than the threshold value for triggering network switching, K is a distance threshold value, and V is_tRepresenting the moving speed of the t-th acquisition moment;

step 3, the signal quality sequence interval is L;

step 3, constructing a plurality of 5G signal quality sequences as follows:

A＝mod[m/L]

B＝m％L

wherein mod [ m/L ] represents an integer part taking m/L, and m% represents a remainder part taking m/L;

the ith 5G signal quality sequence is:

QL_i＝{Q_i,1,Q_i,2,...,Q_i,j}

i∈[1,A]

wherein Q is_i,jRepresents the jth 5G signal quality in the ith 5G signal quality sequence, j ∈ [1, L]；

The A +1 th 5G signal quality sequence is as follows:

QL_A+1＝{Q_A+1,1,Q_A+1,2,...,Q_A+1,B}

wherein Q is_A+1,wRepresents the w-th 5G signal quality in the A + 1-th 5G signal quality sequence, w epsilon [1, B]；

QL₁,QL₂,,...,QL_A+1The a +1 5G signal quality sequences described in step 3.

4. The method for wireless video low-latency transmission under a 5G network according to claim 1, wherein:

and 4, calculating the correlation coefficient of the time series of the 5G signal quality as follows:

wherein Q is_i,jRepresents the jth 5G signal quality in the ith 5G signal quality sequence, j ∈ [1, L]L is the signal quality sequence interval in the step 3, and T is the time point of the acquisition time of acquiring 5G signal quality;

the time sequence corresponding to the ith 5G signal quality sequence is as follows:

TL_i＝{T_i,1,T_i,2,...,T_i,j}

i∈[1,A]

wherein, T_i,jRepresents the time point of the jth 5G signal quality acquisition time in the ith 5G signal quality sequence, j is equal to [1, L ∈]；

μ_TThe average value of the time series corresponding to the ith 5G signal quality series is obtained;

μ_Qis the average of the ith 5G signal quality sequence;

δ_Tthe standard deviation of the time series corresponding to the ith 5G signal quality series;

δ_Qis the standard deviation of the ith 5G signal quality sequence;

r_ia correlation coefficient indicating a time series corresponding to the ith 5G signal quality series and the ith 5G signal quality series;

according to the correlation coefficient r_iSolving whether the sequence is successfully fitted;

when r_i|<c is then TL_i、QL_iThe larger the divergence is, the smaller the data correlation is, and the fitting is considered unsuccessful and is a correlation coefficient threshold;

when r_i|>c is then TL_i、QL_iThe fit was considered successful;

|r_ithe value of | and the correlation degree.

5. The method for wireless video low-latency transmission under a 5G network according to claim 1, wherein:

step 5, adjusting the code rate of video coding according to the mean value of the 5G signal quality sequence, wherein the formula is as follows:

BitRate_i＝

(μ_Q/((QRSS_MAX)-(QRSS_T)))*(BitRate_MAX-BitRate_MIN)+BitRate_MIN；

wherein, Bitrate_iAdjusting the current video bitrate, mu, for the ith 5G signal quality sequence_QThe mean value of the ith 5G signal quality sequence is shown, QRSS _ MAX is the maximum value of network signal quality, QRSS _ T is the threshold value of network switching signal quality, BitRate _ MIN is the minimum value of code rate, and BitRate _ MAX is the maximum value of code rate.

6. The method for wireless video low-latency transmission under a 5G network according to claim 1, wherein:

and 6, constructing a linear model of the 5G signal quality sequence as follows:

TL_i＝k_i QL_i+b_i

wherein k is_iSlope of a linear model for the ith 5G signal quality sequence, b_iFor the axis intercept of the ith 5G signal quality sequence, A_iFirst coefficient of linear model of i 5G signal quality sequence, B_iSecond coefficient of linear model of i-th 5G signal quality sequence, C_iThird coefficient of linear model of i-th 5G signal quality sequence, D_iA fourth coefficient that is a linear model of the ith 5G signal quality sequence;

step 4, the ith 5G signal quality sequence is as follows:

QL_i＝{Q_i,1,Q_i,2,...,Q_i,j}

wherein T is the time point of the acquisition time of acquiring the 5G signal quality, and the ith 5G signal quality sequence QL_iThe corresponding time T sequence is:

TL_i＝{T_i,1,T_i,2,...,T_i,j}

i∈[1,A]

wherein A is the number of 5G signal quality sequences, T_i,jRepresents the time point of the jth 5G signal quality acquisition time in the ith 5G signal quality sequence, j is equal to [1, L ∈]；

And 6, judging the time variation trend of the 5G signal quality sequence:

when r_i|>c and r_i<At 0, k_iIf < 0, it indicates that the data is negatively correlated, i.e. when T is_i,jAt increasing time Q_i,jDecreasing, as a correlation coefficient threshold;

when r_i|>c and r_i>At 0, k_iWhen the ratio is more than 0, the data are positively correlated, namely when T is_i,jAt increasing time Q_i,jAnd is increased.

7. The method for wireless video low-latency transmission under a 5G network according to claim 1, wherein:

and 7, judging whether the two continuous 5G signal quality sequences are successfully fitted according to the correlation coefficients of the two continuous 5G signal quality time sequences:

the two continuous 5G signal quality sequences are as follows: QL_i，QL_i+1；

The correlation coefficients corresponding to the two consecutive 5G signal quality sequences are: r is_i，r_i+1；

|r_i|>c and | r_i+1|>c two consecutive 5G signal quality sequences QL_i，QL_i+1The fitting is successful and is a correlation coefficient threshold value;

i belongs to [1, A ], A is the number of 5G signal quality sequences;

and 7, judging the trend of the two continuous 5G signal quality sequences along with the change of time by the slope of the linear models of the two continuous 5G signal quality sequences as follows:

the slopes corresponding to the two consecutive 5G signal quality sequences are: k is a radical of_i，k_i+1；

k_i<K _ T and K_i+1<K _ T, consecutiveThe slopes corresponding to the two 5G signal quality sequences are both smaller than a slope judgment threshold, wherein K _ T is the slope judgment threshold;

step 7, Q _ MIN is the minimum value of the signal quality of the two continuous 5G signal quality sequences_i,Q_MIN_i+1；

Q _ MIN, the minimum value of the signal quality of the ith 5G signal quality sequence_iThe specific calculation method is in QL_iSearching for the minimum value;

q _ MIN, which is the minimum value of signal qualities of the (i + 1) th 5G signal quality series_i+1The specific calculation method is in QL_i+1Searching for the minimum value;

Q_MIN_i<QRSS _ C and Q _ MIN_i+1<QRSS_C

QRSS_C＝(QRSS_MAX-QRSS_T)*0.5+QRSS_T；

Wherein, QRSS _ C is a signal quality threshold, QRSS _ MAX is a maximum network signal quality, and QRSS _ T is a threshold for network handover signal quality.

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