A video transmission method, server and system based on site discontinuous transmission

Abstract

This application provides a video transmission method, server, and system based on discontinuous transmission at a site, including: obtaining available air interface bandwidth; obtaining video buffer length; selecting the maximum video bitrate when the video buffer length is greater than a threshold upper limit; selecting the minimum video bitrate when the video buffer length is less than a threshold lower limit; selecting a video bitrate not higher than the available air interface bandwidth when the video buffer length is within the threshold range; and using the selected video bitrate as the requested bitrate for the next video block. This application utilizes base station-side wireless data to calculate the available air interface bandwidth, and executes a bitrate adaptive algorithm based on the available air interface bandwidth and client video buffer information to help improve video transmission quality and enhance the user viewing experience. Furthermore, by selectively shutting down the base station's carrier transmission unit in conjunction with video information and wireless link channel conditions, the bandwidth utilization efficiency on the base station side is improved.

Description

Technical Field

[0001] This invention relates to mobile communication technology, and more particularly to a video transmission method, server, and system based on discontinuous transmission from a site. Background Technology

[0002] Mobile communication technology is undergoing rapid development, and 5G (5th Generation Mobile Networks) has arrived. 5G technology will comprehensively improve network speed, stability, reliability, and low latency performance. Based on 5G technology, various innovative scenarios can be enabled, especially video streaming services. In the past, due to technological limitations, the dissemination of higher-definition video was greatly restricted. However, with the continuous development of video shooting and production technologies and telecommunications network technologies, the production and dissemination costs of video media have been continuously reduced, making online dissemination of higher-definition video possible.

[0003] With the development of mobile communication technology, streaming media network protocols are constantly being updated and iterated. Currently, mobile internet video transmission mainly adopts the Dynamic Adaptive Streaming over HTTP (DASH) protocol. Through the HTTP Common Audio-Visual File System (CAFS), high-quality audio-visual content can be transmitted over the network to connected TVs, set-top boxes, and mobile terminal devices. However, due to fluctuations in network conditions and the diversity of video content, users often encounter problems such as video stuttering or low bitrates leading to unclear images when watching videos. To address these issues, network operators and content providers have proposed their own solutions. For example, base stations use carrier aggregation (CA) to increase bandwidth resources and improve the throughput of the transmission link, while clients use adaptive bitrate (ABR) algorithms to dynamically download video segments of different encoding sizes to improve user experience (QoE). However, these methods all have significant drawbacks. First, client-based adaptive bitrate strategies lack real-time information from the base station side, resulting in slow and passive responses to highly dynamic network conditions and poor adaptability. Secondly, carrier aggregation at the base station side consumes a significant amount of bandwidth resources, leading to inefficient bandwidth utilization due to a lack of understanding of client video requirements. Therefore, a video transmission mechanism that combines base station and client information is of great research significance.

[0004] Existing technology as Figure 1As shown, a bitrate adaptive adjustment device and method that balances throughput and video buffering is provided. When the bitrate adaptive module of this device outputs the transmission bitrate information of the requested media segment, it considers both the throughput and video buffering information in other modules: First, the historical throughput is smoothed using the Holt-Winters method to estimate the throughput of the requested media segment; then, based on the current video buffer length in the buffer management module, a buffer weight parameter is calculated, and the estimated throughput is weighted and adjusted to obtain the optimal transmission bitrate; finally, the bitrate adaptive module selects the transmission bitrate of the requested media segment from the list of selectable bitrates based on the optimal transmission bitrate. This technology overcomes the shortcomings of existing technologies while maintaining a relatively excellent playback experience in all aspects.

[0005] Existing technology one primarily addresses the adaptive bitrate issue for video-on-demand in MPEG-DASH systems between clients and servers. While existing technology one can comprehensively consider throughput and buffer length, there is still room for optimization. Details are as follows:

[0006] Application limitations: This invention transforms the actual buffer size into a weighted parameter for correcting the predicted bandwidth by setting minimum and maximum thresholds for the buffer. However, in actual deployments, different video buffer lengths and different video segment sizes usually require different buffer thresholds, which limits the performance of this invention in other scenarios.

[0007] Bitrate decision problem: This invention mainly relies on predicted bandwidth for bitrate decisions; it depends on a single factor. Therefore, in actual deployment, it is prone to causing severe bitrate jitter with fluctuations in network bandwidth, which affects user experience.

[0008] Existing technology two Figure 2 As shown, a video bitrate adaptive adjustment method, apparatus, and electronic device are provided. The method includes: acquiring current network information and current playback information sent by a client while playing the current video; acquiring the current bandwidth load of the server; and inputting the current bandwidth load, current network information, and current playback information into a pre-established bitrate adjustment model corresponding to the current video to obtain an adjustment bitrate for adjusting the client's bitrate. Thus, the adjustment bitrate for adjusting the client's bitrate can be obtained based on the server's current bandwidth load, current network information, and current playback information. This allows for comprehensive consideration of the impact of multiple clients communicating with the server on the server's bandwidth load, as well as the client's current network information and current playback information, to adjust the bitrate of the video being played by the client.

[0009] Existing technology two addresses the adaptive bitrate problem in video-on-demand with multiple clients and servers. While it integrates current network and playback information, overcoming some of the problems and shortcomings of existing adaptive bitrate algorithms, there is still room for optimization. Details are as follows:

[0010] Application limitations: This invention is applied to servers, adjusting the client's video frame rate based on the server's bandwidth load by acquiring current network and playback information sent by the client. Therefore, the optimization process requires the client to send back a large amount of information to the server in real time for decision-making, which is often difficult to implement in actual deployments.

[0011] Bitrate decision problem: The invention first requires pre-training a bitrate adjustment model through reinforcement learning. Model training requires a large amount of user data, and the training convergence process requires a large amount of computing resources.

[0012] Existing technology three Figure 3 As shown, a method for improving the quality and user experience of live video streaming from mobile devices by utilizing aggregated network statistics is disclosed. First, the processing device of the client device obtains the client device's current geographical location and current network conditions such as bandwidth, network type, and network identifier. Based on the bandwidth parameters obtained from the received aggregated network statistics, upload quality parameters for the upload session are initialized to control the format of the upload session. Furthermore, a heuristic estimation model is applied at least once during the upload session to modify the upload quality to adapt to the changing geographical location or network conditions of the client device. Each time the heuristic estimation model is run, a new estimate of the network conditions is obtained using aggregated network statistics of the client device's current network or geographical location.

[0013] Existing technology three utilizes aggregated network statistics to improve the quality and user experience of live video streaming from mobile devices, but many problems still exist in practical applications. These are explained in detail below:

[0014] Application limitations: This invention mainly relies on aggregated network statistics to obtain bandwidth parameters to determine the available bandwidth of the current user and select the best video quality for transmission. However, there are certain limitations in obtaining the user's geographical location and network identifier in actual systems.

[0015] Bitrate decision problem: This invention does not take into account client buffering information and uses as much available bandwidth as possible. Therefore, it is easy to cause video stuttering when bandwidth is insufficient, and it will lead to a waste of bandwidth resources when bandwidth is sufficient. Summary of the Invention

[0016] The purpose of this invention is to provide a video transmission method, server, and system based on discontinuous transmission at a site, which can improve the video transmission quality of the client while improving the bandwidth utilization efficiency of the base station side by combining information from the base station side and the client side.

[0017] The following provides a brief overview of one or more aspects to offer a basic understanding of them. This overview is not an exhaustive summary of all conceived aspects, nor is it intended to identify key or decisive elements of all aspects, nor to define the scope of any or all aspects. Its sole purpose is to present some concepts of one or more aspects in a simplified form to prepare for the more detailed descriptions that follow.

[0018] According to a first aspect of this application, a video transmission method based on discontinuous transmission from a site is provided, comprising:

[0019] Obtain available air interface bandwidth;

[0020] Get the video buffer length;

[0021] When the video buffer length exceeds the upper threshold, the maximum video bitrate is selected;

[0022] When the video buffer length is less than the lower threshold, the minimum video bitrate is selected;

[0023] When the video buffer length is within the threshold range, select a video bitrate that is no higher than the available air interface bandwidth; use the selected video bitrate as the requested bitrate for the next video block.

[0024] In some embodiments, selecting a video bitrate that is not higher than the available air interface bandwidth includes: multiplying the available air interface bandwidth by a loss factor, and selecting a video bitrate that is not higher than the lost bandwidth.

[0025] In some embodiments, the loss factor is 0.8 to 0.9.

[0026] In some embodiments, when the video buffer length is greater than the upper limit of the threshold, after selecting the maximum video bitrate, the method further includes: determining whether the partial carrier antenna link can successfully transmit video at the maximum video bitrate; if so, sending radio frequency switch information to the base station to turn off the excess antennas.

[0027] According to a second aspect of this application, an edge computing server is provided, comprising:

[0028] The bandwidth evaluation module is used to calculate the available air interface bandwidth and send it to the bit rate adaptation module;

[0029] The video evaluation module is used to obtain the video buffer length and send it to the bitrate adaptive module;

[0030] A bitrate adaptive module is used to perform the method described in the first aspect and to transmit the requested video instruction to the DASH storage module;

[0031] The DASH storage module is used to store video clips with different bitrates and resolutions, as well as respond to video requests from the bitrate adaptive module.

[0032] In some embodiments, the bandwidth evaluation module calculates the user's available air interface bandwidth using the Shannon formula based on base station information obtained from the physical layer on the base station side and physical resource block data used in the downlink.

[0033] In some embodiments, the video evaluation module obtains the video buffer length by parsing the HTTP POST command sent by the DASH client.

[0034] In some embodiments, the video evaluation module also obtains the video bitrate and stuttering time of the video player by parsing the HTTP POST command sent by the DASH client, generates the video quality QoE, evaluates the quality of the played video, and assists the bitrate adaptive module in bitrate optimization.

[0035] In some embodiments, the DASH storage module is further configured to maintain MPD files of the DASH protocol, and the bitrate adaptive module selects the bitrate from the MPD files.

[0036] According to a third aspect of this application, a video transmission system is provided, including an edge computing server as described above, a base station, and a DASH client. The base station includes a data acquisition module for acquiring user data and carrier data from the base station side. The DASH client is signal-connected to the base station and the edge computing server, and the edge computing server is signal-connected to the base station.

[0037] In some embodiments, the base station further includes a radio frequency control module, which is used to control the switching of the carrier antenna according to radio frequency switch information.

[0038] The beneficial effects of this invention are: by combining available bandwidth information from the base station and video cache information from the client to optimize video bitrate, it solves the problem that increasing video bitrate with a single optimization variable can cause video stuttering or unclear video. By executing a bitrate adaptive algorithm based on available air interface bandwidth and client video cache information, it helps improve video transmission quality and enhances the user's viewing experience. Attached Figure Description

[0039] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0040] The above-described features and advantages of the present invention will be better understood after reading the following detailed description of embodiments of the present disclosure in conjunction with the accompanying drawings. In the drawings, components are not necessarily drawn to scale, and components having similar related characteristics or features may have the same or similar reference numerals.

[0041] Figure 1 This is a flowchart illustrating the implementation of existing technology one;

[0042] Figure 2 This is a flowchart illustrating the implementation of Existing Technology 2;

[0043] Figure 3 This is a flowchart illustrating the implementation of existing technology three;

[0044] Figure 4 This is a system schematic diagram in one embodiment;

[0045] Figure 5 This is a schematic diagram of a video transmission method in one embodiment;

[0046] Wherein: 1-DASH client; 2-base station; 21-data acquisition module; 22-RF control module; 23-first carrier unit antenna; 24-second carrier unit antenna; 3-MEC server; 31-DASH storage module; 32-bitrate adaptive module; 33-bandwidth evaluation module; 34-video evaluation module. Detailed Implementation

[0047] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments. It should be noted that the aspects described below with reference to the accompanying drawings and specific embodiments are merely exemplary and should not be construed as limiting the scope of protection of the present invention in any way.

[0048] like Figure 4 As shown, this embodiment proposes a video transmission system comprising a DASH client 1, a base station 2, and an edge computing (MEC) server 3. The DASH client 1 is primarily used for downloading and playing DASH videos.

[0049] Base station 2 includes:

[0050] Data acquisition module 21: The data acquisition module 21 acquires user data and carrier data from the base station. The user data mainly describes the configuration information of each user currently connected to the base station and the connection status information between each user and the base station. The carrier data mainly includes configuration information of various parameters such as signal transmission power and coding modulation method.

[0051] Radio frequency control module 22: Receives radio frequency switch information from the bit rate adaptive module 32 to control the shutdown of the base station's carrier unit antennas. In a possible embodiment, base station 2 includes multiple carrier antennas. It can be determined whether some carrier antenna links can successfully transmit video at the maximum video bit rate. If so, radio frequency switch information is sent to the base station to shut down the excess antennas, thereby saving bandwidth resources. In this embodiment, base station 2 is equipped with two carrier unit antennas: a first carrier unit antenna 23 and a second carrier unit antenna 24. By default, both the first carrier unit antenna 23 and the second carrier unit antenna 24 are enabled.

[0052] MEC Server 3 includes:

[0053] DASH storage module 31: Used to store video segments with different bitrates and resolutions and to respond to video requests from the bitrate adaptive module, and to transmit video to DASH client 1; it is also used to maintain the MPD (Media Presentation Description) file of the DASH protocol. The MPD is an XML (Extensible Markup Language) file that fully represents all the information of the video, including the video length, the bitrate and resolution of different video segments, and the segment duration.

[0054] The bitrate adaptive module 32 receives the available air interface bandwidth value sent by the bandwidth evaluation module, combines it with the video quality information returned by the user-side video player, such as the status of the client video buffer, and determines the transmission bitrate of the requested video segment from the list of selectable bitrates. It then transmits the requested video command to the DASH storage module 31. Simultaneously, based on the above information, it determines whether the second carrier unit antenna 24 needs to be switched on or off and sends the RF switch information to the RF control module 22 of the base station 2.

[0055] Bandwidth assessment module 33: Receives base station information such as modulation and coding scheme (MCS) of each carrier and physical resource block (DLOccuPyPRBNum) data used in the downlink sent by data acquisition module 21, calculates the available air interface bandwidth of the user using Shannon formula, and sends the above information to code rate adaptation module 32.

[0056] Video evaluation module 34: Obtains the video bitrate R of the video player by parsing the HTTP POST command sent by the client. k , stuttering time T k Remaining playback time in the buffer (B) k The system collects video information, generates video quality (QoE), evaluates the quality of the played video, and assists the bitrate adaptive module 32 in bitrate optimization.

[0057] like Figure 5 As shown, the video transmission method provided in this embodiment is as follows:

[0058] Step 1: First, obtain the available air interface bandwidth values ​​of the two-carrier antennas from the bandwidth evaluation module, which are as follows: and Total available air interface bandwidth is

[0059] Step 2: Obtain the current video buffer length B of the video player from the video evaluation module. k The video buffer length represents the length of the video that has been downloaded but not yet played, and is used to assist in bitrate adjustment.

[0060] Step 3: When the video buffer length is greater than B H In this embodiment, the length of each video block is l = 4s, and the maximum buffer length is L. max =16s, B H =L max If the maximum video bitrate R is selected, then the maximum video bitrate R is chosen. max And determine the link of the current first carrier unit antenna. Can the code rate of R be successfully transmitted? max If possible, turn off the second carrier unit antenna.

[0061] Step 4: When the video buffer length is less than B L (B L When the bitrate is 1 * 1.5 = 6 seconds, then the minimum video bitrate R is selected. min At this point, the video playback buffer is small, posing a risk of stuttering. Therefore, the lowest bitrate is selected to prevent video stuttering.

[0062] Step 5: When the video buffer length is B L and B H In this case, the video bitrate should be decided based on the assessed available air interface bandwidth, and should not exceed the available air interface bandwidth. To prevent selecting a video bitrate that the network bandwidth cannot handle, the available air interface bandwidth C can be... kMultiply by a loss factor, and then select a video bitrate from the MPD file that is no higher than the network bandwidth after loss. The loss factor can be between 0.8 and 0.9; in this embodiment, it is 0.9. That is, R k+1 ≤C k *0.9.

[0063] Step 6: Set the video bitrate R for the decision. k+1 The request bitrate for the next video block is sent to the DASH storage module, and the radio frequency switch information (except for the judgment of the second carrier unit antenna being turned off in step 3, the second carrier unit antenna is turned on by default) is sent to the radio frequency control module of the base station.

[0064] The following experiments test the improvement of video QoE and base station bandwidth resource utilization of this technical solution, where the QoE expression is as follows:

[0065]

[0066] K represents the number of video blocks downloaded, q(R k )=ln(R k / R min ) Video bitrate R k Mapped to the user's perception of video quality, T k The download bitrate is R. k The buffering time (stuttering time) during video blocks, |q(R) k+1 )-q(R k )| represents the change in video quality (smoothness), and the weighting coefficients for video stuttering and smoothness are 3.68 and 1.0, respectively. The bandwidth resource utilization rate η of the effective transmission video base station is defined as follows:

[0067]

[0068] Where δ(.) indicates whether the second carrier element antenna is used; if not used, it is 0.

[0069] The experiment set up two scenarios and compared the existing rate-based bitrate adjustment algorithm based on the UE download speed as the baseline algorithm. Experimental scenario A was set as a high-speed scenario close to the site, and experimental scenario B was set as a low-speed scenario far from the site. The experimental performance results are shown in Table 1.

[0070] Table 1 Experimental Performance

[0071]

[0072] As shown in Table 1, in scenario A, the average video quality and average QoE performance of the proposed technical solution are improved by 17% and 15% respectively compared to the baseline algorithm, while in scenario B, they are improved by 19% and 24% respectively. Furthermore, the bandwidth resource utilization of the proposed solution is improved by 24% and 8% in both scenarios. Experimental results show that the proposed technical solution not only fully utilizes the base station's wireless air interface transmission capabilities to improve the user viewing experience but also improves the utilization rate of base station bandwidth resources.

[0073] In summary, the beneficial effects of the embodiments of this application are mainly as follows:

[0074] 1. This method uses the underlying physical layer information of the base station to calculate the available air interface bandwidth. Compared with the existing client-based throughput estimation scheme, this method responds quickly to dynamic network conditions and can accurately calculate the air interface bandwidth available to the current user.

[0075] 2. By combining available bandwidth information from the base station and video cache information from the client, video bitrate optimization is achieved, which solves the problem that increasing video bitrate with a single optimization variable can cause video stuttering or unclear video.

[0076] 3. While ensuring successful transmission of high-definition video, the system uses video transmission information to control the switching on and off of the base station's radio frequency antenna, thereby saving bandwidth resources and effectively improving bandwidth utilization.

[0077] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0078] The prior description of this disclosure is provided to enable any person skilled in the art to make or use this disclosure. Various modifications to this disclosure will be apparent to those skilled in the art, and the general principles defined herein may be applied to other variations without departing from the spirit or scope of this disclosure. Therefore, this disclosure is not intended to be limited to the examples and designs described herein, but should be accorded the widest scope consistent with the principles and novel features disclosed herein.

[0079] The above description is merely a preferred example of this application and is not intended to limit this application. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application shall be included within the scope of protection of this application.

Claims

1. An edge computing server, characterized by, The method comprises the following steps: a bandwidth evaluation module for calculating available air interface bandwidth and sending to a rate adaptation module; a video evaluation module for obtaining video buffer length and sending to the rate adaptation module; the rate adaptation module for performing the method comprising the steps of: obtaining available air interface bandwidth; obtaining video buffer length; selecting a maximum video rate when the video buffer length is greater than an upper threshold; selecting a minimum video rate when the video buffer length is less than a lower threshold; selecting a video rate not higher than the available air interface bandwidth when the video buffer length is within a threshold range; selecting a video rate not higher than the available air interface bandwidth, comprising multiplying the available air interface bandwidth by a loss factor and selecting a video rate not higher than the bandwidth after loss; after selecting the maximum video rate when the video buffer length is greater than the upper threshold, further comprising judging whether a part of carrier antenna links can successfully send the maximum video rate and, if so, sending radio frequency switch information to the base station to turn off the excess antennas; and transmitting a request video instruction to a DASH storage module; the DASH storage module for storing video segments of different rates and resolutions and responding to the request video instruction of the rate adaptation module; the bandwidth evaluation module calculates the available air interface bandwidth of the user by using Shannon formula according to the base station information obtained from the base station side and the physical resource block data used in the downlink; the video evaluation module obtains the video buffer length by analyzing the HTTP POST instruction sent by the DASH client; the video evaluation module further obtains the video player video rate and the stall time by analyzing the HTTP POST instruction sent by the DASH client, generates the video quality QoE, evaluates the quality of the played video, and assists the rate adaptation module in rate optimization. The loss factor is 0.8-0.

9.

2. The edge computing server of claim 1, wherein, The DASH storage module is further used for maintaining the MPD file of the DASH protocol, and the rate adaptation module selects the rate from the MPD file.

3. The edge computing server of claim 1, wherein: The edge computing server comprises a base station and a DASH client, the base station comprises a data acquisition module for acquiring user data and carrier data from the base station side, the DASH client is in signal connection with the base station and the edge computing server, and the edge computing server is in signal connection with the base station.

4. A video transmission system characterized by: The base station further comprises a radio frequency control module for controlling the switching of the carrier antenna according to the radio frequency switch information.

5. The video transmission system of claim 4, characterized in that: ​

Images