Recording and broadcasting system audio and video real-time streaming transmission method with adaptive code rate adjustment

Abstract

The invention discloses an audio and video real-time stream transmission method for a recording and broadcasting system with adaptive code rate adjustment, which adopts an adaptive code rate adjustment strategy, dynamically adjusts the code rate according to the network condition, the user equipment performance and the audio and video signal coding efficiency monitored in real time, has higher flexibility and adaptability, and can be used for realizing the real-time transmission of the audio and video. According to the invention, optimization of audio and video real-time stream transmission is realized, and the problem that audio and video transmission is lagged and delayed under the condition of poor network quality due to the fact that an existing recording and broadcasting system mostly adopts a transmission mode with a fixed code rate and the code rate cannot be adjusted in real time according to network conditions and user requirements is effectively solved.

Description

Technical Field

[0001] The present invention relates to the technical field of audio and video real-time streaming transmission, and in particular to an audio and video real-time streaming transmission method of a recording and broadcasting system with adaptive bit rate adjustment. Background Art

[0002] With the development of network technology, real-time audio and video transmission has been widely used in fields such as education and remote conferencing.

[0003] Existing recording and broadcasting systems mostly use a fixed bit rate transmission method, which is unable to adjust the bit rate in real time according to network conditions and user needs. As a result, when the network quality is poor, audio and video transmission may experience freezes and delays, affecting the user experience. Summary of the invention

[0004] The purpose of this section is to summarize some aspects of embodiments of the present invention and briefly introduce some preferred embodiments. Some simplifications or omissions may be made in this section and the specification abstract and the invention title of this application to avoid blurring the purpose of this section, the specification abstract and the invention title, and such simplifications or omissions cannot be used to limit the scope of the present invention.

[0005] In view of the above problems existing in the existing recording and broadcasting system, the present invention is proposed.

[0006] Therefore, the technical problem solved by the present invention is to solve the problem that the existing recording and broadcasting systems mostly adopt a fixed bit rate transmission method, which cannot adjust the bit rate in real time according to network conditions and user needs, resulting in freezes and delays in audio and video transmission when the network quality is poor.

[0007] To solve the above technical problems, the present invention provides the following technical solutions: a method for real-time audio and video streaming transmission of a recording and broadcasting system with adaptive bit rate adjustment, comprising the following steps: S1: initialization stage: determine a series of basic parameters of audio and video signals according to actual transmission requirements, and synchronously set the initial bit rate; S2: real-time monitoring stage: a. real-time monitoring of network bandwidth, delay and packet loss network conditions; b. real-time monitoring of user equipment performance, including processing power and storage space; c. real-time monitoring of encoding efficiency and compression rate of audio and video signals; S3: bit rate adjustment stage: adjust the bit rate according to the network conditions, user equipment performance and encoding efficiency and compression rate of audio and video signals monitored in real time in S2; S4: real-time audio and video streaming transmission stage: a. encode the adjusted audio and video signals; b. encapsulate the encoded audio and video signals to generate a real-time stream; c. transmit the real-time stream to the user equipment.

[0008] As a preferred solution of the audio and video real-time streaming transmission method of the recording and broadcasting system with adaptive bit rate adjustment described in the present invention, the series of basic parameters confirmed in the initialization stage specifically include: audio sampling rate, video resolution, video frame rate and audio and video encoding format.

[0009] As a preferred solution of the audio and video real-time streaming transmission method of the recording and broadcasting system with adaptive bit rate adjustment described in the present invention, wherein: when the bit rate is adjusted in the bit rate adjustment stage: i. when the network bandwidth is sufficient, increase the bit rate to ensure the audio and video quality; ii. when the network bandwidth is insufficient, reduce the bit rate to reduce freezes and delays; iii. when the performance of the user device is insufficient, reduce the bit rate to reduce the burden on the device; iv. when the audio and video signal encoding efficiency is sufficient, increase the bit rate to make full use of the network bandwidth.

[0010] As a preferred solution of the method for real-time streaming of audio and video in a recording and broadcasting system with adaptive bit rate adjustment described in the present invention, the bit rate adjustment stage also includes obtaining the bit rate adjustment percentage according to various data monitored in real time through an embedded bit rate adjustment calculation unit, specifically:

[0011] Real-time monitoring of network status α, specifically including network bandwidth α1, delay information α2, and packet loss information α3;

[0012] Real-time monitoring of the performance β of the user's device, specifically including processing capacity β1 and storage space β2;

[0013] Real-time monitoring of the coding efficiency δ and compression rate γ of audio and video signals;

[0014] The embedded bit rate adjustment calculation unit obtains the bit rate adjustment percentage according to the following formula:

[0015]

[0016] Where η is the bit rate adjustment percentage, α1 is the network bandwidth, α2 is the delay information, α3 is the packet loss information, β1 is the processing capacity, β2 is the storage space, δ is the coding efficiency, γ is the compression rate, 1.62, 1.15 and 1.07 are all normal adjustment constants;

[0017] i. When the network bandwidth is sufficient, α1 is defined as unit 1, and the delay information α2 and the packet loss information α3 are both defined as 0;

[0018] ii. When the network bandwidth is insufficient, α1 is defined as the unit ln2, the delay information α2 and the packet loss information α3 are both defined as 1, and when the user device performance is insufficient, the processing capacity β1 and the storage space β2 are both defined as 0, and when the user device performance is sufficient, the processing capacity β1 and the storage space β2 are both defined as 1.

[0019] As a preferred solution of the method for real-time streaming of audio and video in a recording and broadcasting system with adaptive bit rate adjustment described in the present invention, when the network bandwidth is sufficient, the bit rate is increased to η 1.21 *Original code, ensuring audio and video quality.

[0020] As a preferred solution of the method for real-time streaming of audio and video in a recording and broadcasting system with adaptive bit rate adjustment described in the present invention, when the network bandwidth is insufficient, the bit rate is reduced to η 1.88 *Original code, reducing lag and delay.

[0021] As a preferred solution of the method for real-time streaming of audio and video in a recording and broadcasting system with adaptive bit rate adjustment described in the present invention, when the performance of the user equipment is insufficient, the bit rate is reduced to η 1.65 *Original code, reducing the burden on equipment.

[0022] As a preferred solution of the method for real-time streaming of audio and video in a recording and broadcasting system with adaptive bit rate adjustment described in the present invention, when the coding efficiency of the audio and video signal is sufficient, the bit rate is increased to η 1.19 *Original code, making full use of network bandwidth.

[0023] The beneficial effects of the present invention are as follows: the present invention provides a method for real-time audio and video streaming transmission of a recording and broadcasting system with adaptive bit rate adjustment, which adopts an adaptive bit rate adjustment strategy to dynamically adjust the bit rate according to the real-time monitored network conditions, user equipment performance and audio and video signal coding efficiency, has higher flexibility and adaptability, realizes the optimization of real-time audio and video streaming transmission, and effectively solves the problem that the existing recording and broadcasting systems mostly adopt a fixed bit rate transmission method, which cannot adjust the bit rate in real time according to the network conditions and user needs, resulting in the problem of freeze and delay in audio and video transmission when the network quality is poor. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative labor. Among them:

[0025] Figure 1 The present invention provides an overall method flow chart of the method for real-time audio and video streaming transmission of a recording and broadcasting system with adaptive bit rate adjustment. DETAILED DESCRIPTION

[0026] In order to make the above-mentioned purposes, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are described in detail below in conjunction with the drawings of the specification. Obviously, the described embodiments are part of the embodiments of the present invention, but not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary persons in the art without creative work should fall within the scope of protection of the present invention.

[0027] Existing recording and broadcasting systems mostly use a fixed bit rate transmission method, which is unable to adjust the bit rate in real time according to network conditions and user needs. As a result, when the network quality is poor, audio and video transmission may experience freezes and delays, affecting the user experience.

[0028] Therefore, please refer to Figure 1 The present invention provides a method for real-time audio and video streaming transmission of a recording and broadcasting system with adaptive bit rate adjustment, comprising the following steps:

[0029] S1: Initialization phase: Determine a series of basic parameters of the audio and video signals according to actual transmission requirements, and simultaneously set the initial bit rate;

[0030] S2: Real-time monitoring stage:

[0031] a. Real-time monitoring of network bandwidth, delay and packet loss;

[0032] b. Real-time monitoring of user device performance, including processing power and storage space;

[0033] c. Real-time monitoring of the coding efficiency and compression rate of audio and video signals;

[0034] S3: Bit rate adjustment stage: Bit rate adjustment is performed based on the network status, user equipment performance, and coding efficiency and compression rate of audio and video signals monitored in real time in S2;

[0035] S4: Audio and video real-time streaming transmission stage:

[0036] a. Encode the adjusted audio and video signals;

[0037] b. Encapsulate the encoded audio and video signals to generate real-time streams;

[0038] c. Stream live to user devices.

[0039] Specifically, the series of basic parameters confirmed in the initialization phase include: audio sampling rate, video resolution, video frame rate and audio and video encoding format.

[0040] It should be noted that:

[0041] 1. Audio sampling rate setting:

[0042] Determine the sampling rate of the audio signal, usually 44.1kHz, 48kHz or higher to ensure audio quality;

[0043] The higher the sampling rate, the better the audio quality, but the higher the bit rate required;

[0044] Select an appropriate sampling rate based on actual application scenarios and user needs.

[0045] 2. Video resolution settings:

[0046] Determine the resolution of the video signal, such as 720p, 1080p, or 4K;

[0047] The higher the resolution, the better the video quality, but the larger the data volume and the higher the bandwidth requirement;

[0048] Select the appropriate resolution based on the hardware performance and network environment of the recording and broadcasting system.

[0049] 3. Video frame rate setting:

[0050] Determine the frame rate of the video signal. Common frame rates include 24fps, 30fps, 60fps, etc.

[0051] The higher the frame rate, the smoother the video playback, but it also increases the amount of data;

[0052] Select the frame rate based on the dynamic nature of the content and network conditions.

[0053] 4. Audio and video encoding format settings:

[0054] Select the appropriate audio and video encoding format, such as H.264, H.265, AAC, MP3, etc.;

[0055] The encoding format affects compression efficiency and video quality, and different formats have different requirements for hardware and bandwidth;

[0056] Select the encoding format based on the compatibility and transmission bandwidth of the recording and broadcasting system.

[0057] 5. Initial bit rate setting:

[0058] Determine an appropriate initial bit rate based on the above parameters and expected network conditions;

[0059] The initial bit rate should be lower than the upper limit of the network bandwidth to prevent network congestion;

[0060] The initial bit rate should be set preliminarily according to the actual situation.

[0061] In addition, the initial parameters can be directly set according to the basic parameters obtained above. This does not actually affect the actual situation. It only needs to be set separately according to the actual situation. It does not require accuracy. That is, the setting of the initial bit rate usually needs to consider the following factors:

[0062] Network bandwidth limit: The initial bitrate should not be close to the network bandwidth limit to avoid network congestion when network conditions fluctuate or bandwidth is shared.

[0063] Audio and video quality requirements: Select the corresponding bit rate based on the requirements for audio and video quality. For example, high-definition video requires a higher bit rate to maintain quality, while standard-definition video can use a lower bit rate.

[0064] Coding efficiency: The selected coding format and parameters will also affect the required bit rate. An efficient coding format can maintain good quality at a lower bit rate.

[0065] User experience: Determine an appropriate bit rate based on the target user group's expectations for video quality and network conditions.

[0066] Generally speaking, the initial bit rate can be set according to the following principles:

[0067] For standard definition (SD) video, the initial bit rate can be set between 1-2 Mbps (megabits per second).

[0068] For high-definition (HD) video (720p), the initial bit rate can be set between 2-5Mbps.

[0069] For full high-definition (FHD) video (1080p), the initial bit rate can be set between 5-10Mbps.

[0070] For ultra-high-definition (UHD) video (4K), the initial bit rate can be set between 10-25Mbps.

[0071] It should be noted that the above values ​​are for reference only. The following factors should also be considered during actual settings:

[0072] Network bandwidth fluctuations: If the network bandwidth fluctuates greatly, you may need to set the initial bitrate lower to adapt to the reduction in bandwidth.

[0073] Number of concurrent streams: If multiple streams are transmitted simultaneously in the network, the initial bit rate should be reduced accordingly to avoid excessive bandwidth usage.

[0074] Network congestion control: In some scenarios, the network congestion control protocol may dynamically adjust the bit rate according to the network conditions, so the initial bit rate should leave a certain adjustment space.

[0075] Ultimately, the initial bitrate setting should be optimized through experiments and actual testing to ensure a satisfactory user experience under different network conditions.

[0076] It should be noted that in the real-time monitoring stage:

[0077] a. Real-time monitoring of network status:

[0078] Network bandwidth monitoring:

[0079] Use network quality monitoring tools (such as ping, traceroute, netstat, etc.) to periodically send probe packets to measure the round-trip time (RTT) and transmission rate from the server to the client;

[0080] Apply bandwidth estimation algorithms (such as TCP congestion window size estimation, rate-based estimation, etc.) to estimate the current available network bandwidth;

[0081] Monitor the changing trend of network bandwidth so as to adjust the bit rate in time.

[0082] Latency monitoring:

[0083] Evaluate network latency by measuring packet round trip time (RTT);

[0084] Use timestamps and sequence numbers to track when packets are sent and received, and calculate one-way and round-trip delays;

[0085] An increase in latency may indicate network congestion and the bit rate needs to be reduced in a timely manner.

[0086] Packet loss monitoring:

[0087] Detect packet loss through sequence number and acknowledgment mechanisms;

[0088] Monitor the packet loss rate. If the packet loss rate exceeds a threshold, the bit rate may be reduced to reduce network congestion.

[0089] b. Real-time monitoring of user equipment performance:

[0090] Processing capacity monitoring:

[0091] Collect information such as CPU usage, memory usage, and GPU load through client software;

[0092] Analyze these metrics to determine whether the client device has sufficient processing power to decode and play audio and video streams.

[0093] Storage space monitoring:

[0094] Check the storage space on the client device to ensure that there is enough space to cache audio and video data;

[0095] If storage space is insufficient, you may need to adjust the cache strategy or reduce the bit rate to reduce storage requirements.

[0096] c. Real-time monitoring of the coding efficiency and compression rate of audio and video signals:

[0097] Coding efficiency monitoring:

[0098] Monitor the encoder's operating status, including encoding speed and resource consumption;

[0099] Analyze the data output by the encoder to ensure that the encoding process meets the expected compression rate and quality.

[0100] Compression rate monitoring:

[0101] Evaluate the compression ratio of audio and video signals, that is, the size ratio of original data to compressed data;

[0102] If the compression ratio is unusual, you may need to adjust the encoding parameters to optimize the balance between data size and video quality.

[0103] Through the meticulous work in the above real-time monitoring stage, the system can collect key data in the audio and video transmission process, thereby providing a decision-making basis for the bit rate adjustment module to ensure stable transmission and high-quality playback of audio and video streams.

[0104] Furthermore, when the bit rate is adjusted during the bit rate adjustment phase:

[0105] i. When the network bandwidth is sufficient, increase the bit rate to ensure the quality of audio and video;

[0106] ii. When the network bandwidth is insufficient, reduce the bit rate to reduce freezes and delays;

[0107] iii. When the performance of the user equipment is insufficient, reduce the bit rate to reduce the burden on the equipment;

[0108] iv. When the encoding efficiency of audio and video signals is sufficient, increase the bit rate to make full use of the network bandwidth.

[0109] It should be noted that the current adequacy of network bandwidth, the adequacy of user equipment performance, and the adequacy of audio and video signal coding efficiency are all directly judged based on actual monitoring conditions. This is a mature application of existing technologies and there are no corresponding technical difficulties.

[0110] Furthermore, the bit rate adjustment stage also includes obtaining the bit rate adjustment percentage according to various data monitored in real time through the embedded bit rate adjustment calculation unit, specifically:

[0111] Real-time monitoring of network status α, specifically including network bandwidth α1, delay information α2, and packet loss information α3;

[0112] Real-time monitoring of the performance β of the user's device, specifically including processing capacity β1 and storage space β2;

[0113] Real-time monitoring of the coding efficiency δ and compression rate γ of audio and video signals;

[0114] The embedded bit rate adjustment calculation unit obtains the bit rate adjustment percentage according to the following formula:

[0115]

[0116] Where η is the bit rate adjustment percentage, α1 is the network bandwidth, α2 is the delay information, α3 is the packet loss information, β1 is the processing capacity, β2 is the storage space, δ is the coding efficiency, γ is the compression rate, 1.62, 1.15 and 1.07 are all normal adjustment constants;

[0117] i. When the network bandwidth is sufficient, α1 is defined as unit 1, and the delay information α2 and the packet loss information α3 are both defined as 0;

[0118] ii. When the network bandwidth is insufficient, α1 is defined as the unit ln2, the delay information α2 and the packet loss information α3 are both defined as 1, and when the user device performance is insufficient, the processing capacity β1 and the storage space β2 are both defined as 0, and when the user device performance is sufficient, the processing capacity β1 and the storage space β2 are both defined as 1.

[0119] Specifically, when the network bandwidth is sufficient, the bit rate is increased to η 1.21 *Original code, ensuring audio and video quality.

[0120] Specifically, when the network bandwidth is insufficient, the bit rate is reduced to η 1.88 *Original code, reducing lag and delay.

[0121] Specifically, when the performance of the user equipment is insufficient, the bit rate is reduced to η 1.65 *Original code, reducing the burden on equipment.

[0122] Specifically, when the encoding efficiency of the audio and video signals is sufficient, the bit rate is increased to η 1.19 *Original code, making full use of network bandwidth.

[0123] In order to verify the technical effect of the method for real-time audio and video streaming transmission of a recording and broadcasting system with adaptive bit rate adjustment of the present invention, the following is an experimental verification process, including experimental steps and data proof tables.

[0124] Test verification process:

[0125] Step 1: Preparation

[0126] A control group and an experimental group were set up. The control group used a traditional fixed bit rate recording and broadcasting system, and the experimental group used the adaptive bit rate adjustment recording and broadcasting system proposed in the present invention.

[0127] Ensure that the two groups of test environments are identical, including network conditions, user device performance, etc.

[0128] Step 2: Initial Setup

[0129] Both the control group and the experimental group determined a series of basic parameters of the audio and video signals according to actual transmission requirements and set the initial bit rate.

[0130] Step 3: Real-time monitoring and data collection

[0131] During the experiment, the network status (bandwidth, latency, packet loss), user device performance (processing power, storage space), and the coding efficiency and compression rate of audio and video signals are monitored in real time.

[0132] Collect audio and video transmission data of the experimental group and the control group under different network conditions.

[0133] Step 4: Adaptive bitrate adjustment

[0134] The experimental group dynamically adjusted the bit rate based on real-time monitoring data.

[0135] The control group maintained a fixed bit rate.

[0136] Step 5: Data comparison and analysis

[0137] Compare the audio and video transmission effects of the experimental group and the control group under the same network conditions, including indicators such as the number of freezes, delay duration, and audio and video quality.

[0138] Analyze the effectiveness of adaptive bitrate adjustment.

[0139] Data certification form:

[0140]

[0141]

[0142] The experimental group significantly reduced the number of freezes and delays, while improving audio and video quality through adaptive bit rate adjustment.

[0143] The data show that the adaptive bit rate adjustment recording and broadcasting system of the present invention can effectively adjust the bit rate according to the real-time status of the network and user equipment, thereby improving the audio and video transmission effect.

[0144] The present invention provides an audio and video real-time streaming transmission method for a recording and broadcasting system with adaptive bit rate adjustment. The method adopts an adaptive bit rate adjustment strategy to dynamically adjust the bit rate according to the real-time monitored network status, user equipment performance and audio and video signal coding efficiency. The method has higher flexibility and adaptability, realizes the optimization of audio and video real-time streaming transmission, and effectively solves the problem that the existing recording and broadcasting systems mostly adopt a fixed bit rate transmission mode, and the bit rate cannot be adjusted in real time according to the network status and user needs, resulting in the problem of freeze and delay in audio and video transmission when the network quality is poor.

[0145] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

Claims

1. A method for real-time audio and video streaming transmission in a recording and broadcasting system with adaptive bit rate adjustment, characterized in that: The steps include: S1: Initialization phase: Determine a series of basic parameters of the audio and video signals according to actual transmission requirements, and simultaneously set the initial bit rate; S2: Real-time monitoring stage: a. Real-time monitoring of network bandwidth, delay and packet loss; b. Real-time monitoring of user device performance, including processing power and storage space; c. Real-time monitoring of the coding efficiency and compression rate of audio and video signals; S3: Bit rate adjustment stage: Bit rate adjustment is performed based on the network status, user equipment performance, and coding efficiency and compression rate of audio and video signals monitored in real time in S2; S4: Audio and video real-time streaming transmission stage: a. Encode the adjusted audio and video signals; b. Encapsulate the encoded audio and video signals to generate real-time streams; c. Stream live to user devices.

2. The method for real-time audio and video streaming transmission of a recording and broadcasting system with adaptive bit rate adjustment according to claim 1, characterized in that: The series of basic parameters confirmed in the initialization phase include: audio sampling rate, video resolution, video frame rate and audio and video encoding format.

3. The method for real-time audio and video streaming of a recording and broadcasting system with adaptive bit rate adjustment according to claim 2 is characterized in that the bit rate When adjusting the bit rate during the adjustment phase: i. When the network bandwidth is sufficient, increase the bit rate to ensure the quality of audio and video; ii. When the network bandwidth is insufficient, reduce the bit rate to reduce freezes and delays; iii. When the performance of the user equipment is insufficient, reduce the bit rate to reduce the burden on the equipment; iv. When the encoding efficiency of audio and video signals is sufficient, increase the bit rate to make full use of the network bandwidth.

4. The method for real-time audio and video streaming transmission of a recording and broadcasting system with adaptive bit rate adjustment according to claim 3 is characterized in that: The bit rate adjustment stage also includes obtaining the bit rate adjustment percentage according to various data monitored in real time through the embedded bit rate adjustment calculation unit, specifically: Real-time monitoring of network status α, specifically including network bandwidth α1, delay information α2, and packet loss information α3; Real-time monitoring of the performance β of the user's device, specifically including processing capacity β1 and storage space β2; Real-time monitoring of the coding efficiency δ and compression rate γ of audio and video signals; The embedded bit rate adjustment calculation unit obtains the bit rate adjustment percentage according to the following formula: Where η is the bit rate adjustment percentage, α1 is the network bandwidth, α2 is the delay information, α3 is the packet loss information, β1 is the processing capacity, β2 is the storage space, δ is the coding efficiency, γ is the compression rate, 1.62, 1.15 and 1.07 are all normal adjustment constants; i. When the network bandwidth is sufficient, α1 is defined as unit 1, and the delay information α2 and the packet loss information α3 are both defined as 0; ii. When the network bandwidth is insufficient, α1 is defined as the unit ln2, the delay information α2 and the packet loss information α3 are both defined as 1, and when the user device performance is insufficient, the processing capacity β1 and the storage space β2 are both defined as 0, and when the user device performance is sufficient, the processing capacity β1 and the storage space β2 are both defined as 1.

5. The method for real-time audio and video streaming transmission of a recording and broadcasting system with adaptive bit rate adjustment according to claim 4, characterized in that: When the network bandwidth is sufficient, increase the bit rate to η 1.21 *Original code, ensuring audio and video quality.

6. The method for real-time audio and video streaming transmission of a recording and broadcasting system with adaptive bit rate adjustment according to claim 4, characterized in that: When the network bandwidth is insufficient, reduce the bit rate to η 1.88 *Original code, reducing lag and delay.

7. The method for real-time audio and video streaming transmission of a recording and broadcasting system with adaptive bit rate adjustment according to claim 4, characterized in that: When the performance of the user equipment is insufficient, reduce the bit rate to η 1.65 *Original code, reducing the burden on equipment.

8. The method for real-time audio and video streaming transmission of a recording and broadcasting system with adaptive bit rate adjustment according to claim 4, characterized in that: When the encoding efficiency of audio and video signals is sufficient, the bit rate is increased to η 1.19 *Original code, making full use of network bandwidth.

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