A channel reservation method for video service quality guarantee

Abstract

The application discloses a channel reservation method for video service quality guarantee. First, a V-ST A maps a video frame to a static queue; then, the V-ST A sends a channel reservation request frame; next, a VR-ST A replies a channel reservation response frame; then, the channel reservation response frame is received; finally, in an SP stage, all stations need to end current data transmission, and ensure that the channel is in an idle state when the SP starts. The application can reasonably map different video frame types to different priorities according to a cross-layer queue mapping mechanism, and flexibly perform channel reservation, thereby guaranteeing the QoS requirement of low-latency and high-reliability video stream services.

Description

Technical Field

[0001] This invention belongs to the field of network technology, specifically relating to a channel reservation method for ensuring video service quality. Background Technology

[0002] With the rapid development of information technology, Wireless Local Area Networks (WLANs), with Wi-Fi networks as a typical example, have become an important component of modern communication infrastructure, profoundly impacting people's daily lives and work. Due to their high transmission rates, low costs, and open accessibility, WLANs have received widespread attention from industry and academia. Since the establishment of the 802.11 Committee by the Institute of Electrical and Electronics Engineers (IEEE) in 1990, the Wi-Fi protocol has gradually developed into an important standard in the field of wireless communication. In 1997, IEEE released the first WLAN protocol, the IEEE 802.11 standard, marking the official start of WLAN technology. With the continuous development of wireless communication technology and the increasing demands, the IEEE 802.11 protocol family has undergone several important technological evolutions and expansions, such as IEEE 802.11a / b / g / n / ac / ax, and the 802.11be standard is expected to be released in 2025, and the 802.11bn standard is expected to be released in 2028. Each generation of the protocol has been optimized for new application scenarios and ever-changing needs, achieving significant improvements in transmission rate, spectrum utilization, anti-interference capabilities, and multi-user support to meet the more complex application requirements of the future.

[0003] In WLANs, channel access is primarily based on the Carrier Sense Multiple Access with Collision Avoidance (CSMA / CA) mechanism. This mechanism reduces collisions and improves efficiency by monitoring the air interface status and employing a random backoff algorithm. Early versions of the IEEE 802.11 standard used the Distributed Coordination Function (DCF) as the basic channel access protocol, suitable for general data transmission scenarios. However, with the rise of real-time services such as voice and video, IEEE 802.11 introduced the Enhanced Distributed Channel Access (EDCA) mechanism to better support Quality of Service (QoS). This mechanism ensures timely transmission of critical traffic by differentiating priority queues. However, in practical applications, limited spectrum resources, significant interference, and simultaneous access by multiple users make more efficient channel utilization, collision reduction, and improved overall throughput a key challenge in wireless LAN environments.

[0004] With the rapid development of mobile communication technology and the Internet, video traffic has been steadily increasing as a percentage of total network traffic, becoming one of the core drivers of network traffic growth. From high-definition video-on-demand to ultra-high-definition live video streaming, and new forms of video applications such as virtual reality and augmented reality, user demand for high-quality video content is showing an exponential growth trend. These applications not only pose significant challenges to network bandwidth but also impose stringent requirements on transmission latency, jitter, and reliability. Against this backdrop, real-time interaction, online live streaming, and other application scenarios have further raised expectations for network performance. On the one hand, these scenarios require the ability to efficiently and stably transmit large-scale video traffic even with limited or unevenly distributed bandwidth resources, avoiding service quality degradation due to resource bottlenecks. On the other hand, the network must be able to achieve low-latency, high-reliability transmission performance in complex and dynamic environments to ensure a smooth user experience when watching videos or participating in real-time interactions.

[0005] The EDCA mechanism in IEEE 802.11 is a QoS guarantee mechanism proposed in the IEEE 802.11e standard, designed to address the priority transmission issue for different types of services in WLANs. Through the EDCA mechanism, the network can perform differentiated channel access control for different types of service traffic based on the priority of data flows, thereby improving the QoS of latency-sensitive services such as video and voice.

[0006] The EDCA mechanism achieves QoS guarantees by dividing data flows into four different Access Categories (ACs), such as... Figure 1 As shown. Each AC is assigned a different priority based on the characteristics of the service, specifically categorized as follows:

[0007] 1) Background type (AC_Background, AC_BK): Background traffic, lowest priority, usually used for file download or non-real-time data transmission.

[0008] 2) Best-effort type (AC_Best-Effort, AC_BE): Best-effort type traffic, ordinary services without special priority, suitable for general data transmission.

[0009] 3) Video type (AC_Video, AC_VI): Video traffic that is more sensitive to latency and jitter, with higher priority than AC_BK and AC_BE.

[0010] 4) Voice type (AC_Voice, AC_VO): Voice traffic with the highest requirements for latency and jitter, and has the highest priority.

[0011] The EDCA mechanism prioritizes different service flows and meets their QoS requirements by setting different parameters such as Arbitration Inter-Frame Space (AIFS), Contention Window (CW), and Transmission Opportunity (TXOP) limits for different service categories. The roles of these parameters in the EDCA mechanism will be explained below.

[0012] (1) AIFS

[0013] In the EDCA mechanism, AIFS defines the time slot that each AC must wait when it detects that the channel is idle. Higher priority service classes have shorter AIFS values, enabling them to detect the idle state of the channel earlier and quickly initiate transmission requests, thus reducing channel waiting time.

[0014] Depend on Figure 2 As shown, different Inter-Frame Spaces (IFS) are all designed based on the same basic time architecture. All IFS time periods are extended from the Short Inter-Frame Space (SIFS) as the base time slice. Specifically, the AIFS consists of SIFS and several time slots, with different priority services having different numbers of time slots. The calculation formula is as follows:

[0015]

[0016] in, This indicates the number of time slots associated with service priority. The IEEE 802.11e standard defines different ACs... The values ​​are shown in Table 1. Higher-priority services use smaller values. The higher priority service can enter the channel contention state more quickly, while lower priority services have to wait for a longer AIFS time, causing them to lag behind in the channel contention.

[0017] Table 1. AIFS of the four ACs in EDCA STA Configuration Table

[0018]

[0019] Through this design, the AIFS parameters provide the foundation for QoS guarantees in the EDCA mechanism, ensuring that high-priority services can obtain channel resources first, thereby meeting their strict requirements for latency and jitter.

[0020] (2) CW

[0021] CW (Crossover Time) is one of the key parameters controlling channel contention in the EDCA (Electronic Access Control) mechanism. When a STA attempts to access the channel, after detecting that the channel is idle, it needs to select a random backoff time, which is randomly selected within the range specified by CW. CW is determined by... and These two parameters determine the backoff value. When the STA first enters channel contention, the backoff value will be in the range [0, ...]. The value is randomly selected within the range of -1]. If the contention fails, i.e., the channel is occupied before the backoff time ends, the CW value increases exponentially until it reaches [the desired value]. Until then. This mechanism ensures that high-priority services use smaller... and This shortens the backoff time, allowing it to acquire the channel first and ensuring the QoS of high-priority services.

[0022] As shown in Table 2, the CW parameter configurations differ for different ACs. Specifically, AC_VO and AC_VI are set to smaller values. and This ensures that high-priority services can access the channel faster, thereby improving their transmission performance; while AC_BE and AC_BK have a larger CW range and are relatively lagging in channel contention, avoiding interference with high-priority services.

[0023] Table 2. CW parameter configuration table for four AC types of EDCA

[0024]

[0025] By properly configuring CW parameters, EDCA can effectively guarantee the QoS of different services, enabling high-priority services to have a higher success rate when accessing the channel, and significantly improving the transmission stability and response speed of real-time services.

[0026] (3) TXOP

[0027] TXOP is one of the key parameters in the EDCA mechanism, mainly used to control the maximum data transmission duration after each successful channel acquisition. The TXOP limit parameter allows each AC to occupy the channel for a fixed period of time after successfully acquiring the channel, without having to re-compete for each data packet sent.

[0028] Table 3. TXOP Limitation Configuration Table for Four Types of EDCA ACs

[0029]

[0030] As shown in Table 3, the EDCA mechanism allocates different TXOP limit durations based on the priority of different ACs. AC_VO and AC_VI, as latency-sensitive access classes, are given longer TXOP values, allowing them to transmit more data packets during a single channel access period. This not only effectively reduces the average latency and contention overhead of these services but also significantly improves their QoS. Conversely, AC_BE and AC_BK have TXOP values ​​set to 0, indicating that they can only re-enter channel contention after sending a single data packet, thus freeing up more resources for high-priority services and ensuring their latency and jitter requirements.

[0031] The Quality of Service (QoS) of video services has its own characteristics. For example, the data packets generated at the application layer based on video encoding often have layered or frame-classified features. For instance, video streams can be divided into different frame types such as I-frames, B-frames, and P-frames, and the performance of different frame transmission types contributes differently to or impacts the overall video QoS. However, in existing technologies, WLANs rely solely on MAC layer mechanisms to attempt to guarantee the QoS of video services, often neglecting the frame types and characteristics at the application layer. This results in inefficient resource allocation and management, making it difficult to meet the QoS requirements of video services. Summary of the Invention

[0032] To overcome the shortcomings of existing technologies, this invention provides a channel reservation method for ensuring video service quality (QoS). First, the V-STA performs static queue mapping on video frames; then, the V-STA sends a channel reservation request frame; next, the VR-STA replies with a channel reservation response frame; subsequently, the VR-STA receives the channel reservation response frame; finally, during the SP phase, all stations must terminate their current data transmission to ensure the channel is idle at the start of SP. This invention can reasonably map different video frame types to different priorities according to a cross-layer queue mapping mechanism and flexibly execute channel reservations, ensuring the QoS requirements of low-latency and high-reliability video streaming services.

[0033] The technical solution adopted by this invention to solve its technical problem is as follows:

[0034] Step 1: V-STA performs static queue mapping on video frames;

[0035] V-STA's MAC layer maps different video frames to different priority queues according to their frame type;

[0036] Depending on the encoding standard used, the video stream is encoded into multiple types of frames, denoted as Type 1, Type 2, ..., Type N. Each type of frame has a different impact on the video transmission quality. In the V-STA MAC layer, there are multiple queues. The MAC layer uniquely maps each type of video frame to a priority queue. Different types of video frames are allowed to be mapped to the same priority queue.

[0037] Step 2: V-STA sends a channel reservation request frame;

[0038] After completing the queue mapping, the V-STA sends a channel reservation request frame to the VR-STA to reserve channel resources and ensure the transmission requirements of critical frames.

[0039] The channel reservation request frame contains the following information:

[0040] 1) Video frame type: Used to indicate the type of video frame;

[0041] 2) SP start time: Aligned with the generation time of subsequent V-STA keyframes;

[0042] 3) SP duration: Allow sufficient time for transmitting video frames;

[0043] 4) SP arrival cycle: Based on GOP characteristics, plan the SP arrival cycle of V-STA;

[0044] 5) Silence interval duration: Sets the transmission duration of key frames during the silence period;

[0045] Step 3: VR-STA responds with a channel reservation acknowledgment frame;

[0046] After receiving a channel reservation request frame from a V-STA, the VR-STA replies with a response frame; the response frame includes two implementation methods.

[0047] In Implementation Method 1, the response result field is used to indicate whether the V-STA's channel reservation request is agreed to; if agreed, all subsequent fields must be completely consistent with the information in the channel reservation request frame; if not agreed, all subsequent fields have no effect.

[0048] In implementation method 2, the channel reservation response frame replied by the VR-STA can carry channel reservation information of one or more V-STAs. The STA identifier in each reservation information of the VR-STA is used to indicate the V-STA. A special STA identifier value can be introduced to represent all STAs. All remaining fields are completely consistent with the information in the channel reservation request frame. If the VR-STA does not agree to the channel reservation request of a certain V-STA, the reservation information of that V-STA will not be included in the response frame.

[0049] Step 4: Receive the channel reservation response frame;

[0050] After receiving the channel reservation response frame from the VR-STA, if the channel reservation response frame agrees to the V-STA's channel reservation request, the V-STA records the SP information of the channel reservation and plans to communicate with the VR-STA in the SP.

[0051] After receiving the channel reservation response frame from the VR-STA, the NV-STA records the SP information of the channel reservation;

[0052] Step 5: SP Phase;

[0053] Before the SP reservation begins, all stations must stop their current data transmission to ensure that the channel is idle when the SP starts.

[0054] The NV-STA remains silent from the start of the SP for a duration specified by the silence interval, in order to avoid interfering with the scheduled transmissions of the V-STA and VR-STA.

[0055] V-STA prioritizes transmitting the reserved frame types from the start of SP to ensure timely transmission of key frames and reduce the impact of latency on video quality; if the reserved frame types have been transmitted, other frame types are transmitted.

[0056] A computer program that causes a computer to perform the above-described channel reservation method.

[0057] An electronic device includes: a processor and a memory; the memory is used to store a computer program, and the processor is used to execute the computer program stored in the memory to cause the electronic device to perform the channel reservation method described above.

[0058] A computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the above-described channel reservation method.

[0059] A chip includes a processor for retrieving and running a computer program from a memory, causing a device equipped with the chip to perform the channel reservation method described above.

[0060] A computer program product includes a computer storage medium storing a computer program, the computer program including instructions executable by at least one processor, which, when executed by the at least one processor, implement the aforementioned channel reservation method.

[0061] The beneficial effects of this invention are as follows:

[0062] This invention can reasonably map different video frame types to different priorities according to the cross-layer queue mapping mechanism, and flexibly perform channel reservation, thus ensuring the QoS requirements of low latency and high reliability video streaming services. Attached Figure Description

[0063] Figure 1 These are the four queues for the EDCA mechanism;

[0064] Figure 2 A schematic diagram of AIFS;

[0065] Figure 3 Assign a graph to the static queue;

[0066] Figure 4 The information that needs to be carried in the channel reservation request frame;

[0067] Figure 5 Add a field diagram to the channel reservation response frame: (a) Implementation method 1 of the channel reservation response frame, (b) Implementation method 2 of the channel reservation response frame;

[0068] Figure 6 This is a flowchart of the channel reservation scheme. Detailed Implementation

[0069] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0070] In this invention, "site" includes both AP and non-AP STA. The transmitting end refers to the site that needs to transmit video traffic (Video Station, V-STA), the receiving end is the site that receives and processes video traffic (Video Receiving Station, VR-STA), and other nodes do not participate in the generation or reception of video traffic (Non-Video Station, NV-STA).

[0071] The implementation example uses static cross-layer queue mapping and static setting of silent interval duration in WLAN to ensure the transmission of video key frames, thereby ensuring the QoS of the video.

[0072] Step 1: V-STA performs static queue mapping on video frames.

[0073] V-STA's MAC layer maps different video frames to different priority queues based on their frame type. Specifically, depending on the encoding standard used, video streams are typically encoded into multiple frame types (denoted as Type 1, Type 2, ..., Type N), each with a different impact on video transmission quality. In V-STA's MAC layer, multiple queues often exist (e.g., Queue 1, Queue 2, ..., Queue M). The MAC layer uniquely maps each type of video frame to a single priority queue. It should be noted that different types of video frames are allowed to be mapped to the same priority queue.

[0074] For example, if a video stream contains only I-frames and B-frames, I-frames typically carry core video information and have a higher transmission priority. B-frames (bidirectional prediction frames), on the other hand, are a frame type that enhances video performance but have relatively lower importance to overall video quality. Assuming the V-STA MAC layer has four queues: AC_VO, AC_VI, AC_BE, and AC_BK, I-frames can be mapped to the AC_VO queue, and B-frames to the AC_VI queue, as follows: Figure 3 As shown.

[0075] Step 2: V-STA sends a channel reservation request frame;

[0076] After completing the queue mapping, the V-STA needs to send a channel reservation request frame to the VR-STA to reserve channel resources and ensure the transmission requirements of critical frames.

[0077] The channel reservation request frame contains the following information:

[0078] 1) Video frame type: Used to indicate the type of video frame, such as one or more frames such as I-frame, B-frame, P-frame, etc.

[0079] 2) SP start time: precisely aligned with the generation time of subsequent V-STA keyframes.

[0080] 3) SP duration: Allow sufficient time for transmitting video frames.

[0081] 4) SP arrival cycle: Combine the GOP characteristics to plan the SP arrival cycle of V-STA.

[0082] 5) Silence interval duration: Set the transmission of key frames during the silence period.

[0083] Step 3: VR-STA responds with a channel reservation acknowledgment frame;

[0084] After receiving the channel reservation request frame from the V-STA, the VR-STA replies with a response frame. The response frame has two implementation methods, with implementation method 1 being... Figure 5 As shown in (a), the response result field indicates whether the V-STA's channel reservation request is accepted; for example, a value of 0 represents acceptance, and a value of 1 represents disagreement. If accepted, all subsequent fields must be completely consistent with the information in the channel reservation request frame. If disagreed, all subsequent fields have no effect.

[0085] Implementation method 2 is Figure 5 As shown in (b), the channel reservation response frame replied by the VR-STA can carry channel reservation information for one or more V-STAs. The STA identifier in each reservation information of the VR-STA is used to indicate the V-STA, and a special STA identifier value can be introduced to represent all STAs. All remaining fields must be completely consistent with the information in the channel reservation request frame. If the VR-STA does not agree to the channel reservation request of a V-STA, then the reservation information of that V-STA should not be included in the response frame.

[0086] Step 4: Receive the channel reservation response frame;

[0087] After receiving the channel reservation response frame from the VR-STA, if the channel reservation response frame agrees to the V-STA's channel reservation request, the V-STA records the SP information of the channel reservation and plans to communicate with the VR-STA in the SP.

[0088] After receiving the channel reservation response frame from the VR-STA, the NV-STA records the SP information of the channel reservation.

[0089] Step 5: SP Phase;

[0090] like Figure 6 As shown, before the SP reservation begins, all stations must stop their current data transmission to ensure that the channel is idle when the SP begins.

[0091] The NV-STA remains silent from the start of the SP for a duration specified by the silence interval, in order to avoid interfering with the scheduled transmissions of the V-STA and VR-STA.

[0092] V-STA must prioritize transmitting the reserved frame types from the start of the SP (Service Packet) to ensure timely transmission of key frames and minimize the impact of latency on video quality. Once the reserved frame types have been transmitted, other frame types can be transmitted.

Claims

1. A channel reservation method for video service quality assurance, characterized in that, Includes the following steps: Step 1: V-STA performs static queue mapping on video frames; V-STA's MAC layer maps different video frames to different priority queues according to their frame type; Depending on the encoding standard used, the video stream is encoded into multiple types of frames, denoted as Type 1, Type 2, ..., Type N. Each type of frame has a different impact on the video transmission quality. In the V-STA MAC layer, there are multiple queues. The MAC layer uniquely maps each type of video frame to a priority queue. Different types of video frames can be mapped to the same priority queue; Step 2: V-STA sends a channel reservation request frame; After completing the queue mapping, the V-STA sends a channel reservation request frame to the VR-STA to reserve channel resources and ensure the transmission requirements of critical frames. The channel reservation request frame contains the following information: 1) Video frame type: Used to indicate the type of video frame; 2) SP start time: Aligned with the generation time of subsequent V-STA keyframes; 3) SP duration: Allow sufficient time for transmitting video frames; 4) SP arrival cycle: Based on GOP characteristics, plan the SP arrival cycle of V-STA; 5) Silence interval duration: Sets the transmission duration of key frames during the silence period; Step 3: VR-STA responds with a channel reservation acknowledgment frame; After receiving a channel reservation request frame from a V-STA, the VR-STA replies with a response frame; the response frame includes two implementation methods. In implementation method 1, the response result field is used to indicate whether the V-STA's channel reservation request is agreed to; If agreed, all subsequent fields must be completely consistent with the information in the channel reservation request frame; If you disagree, all subsequent fields will have no effect. In implementation method 2, the channel reservation response frame replied by the VR-STA carries channel reservation information of one or more V-STAs. The STA identifier in each reservation information of the VR-STA is used to indicate the V-STA, and a special STA identifier value can be introduced to represent all STAs; all remaining fields are completely consistent with the information in the channel reservation request frame. If a VR-STA does not agree to a V-STA's channel reservation request, the reservation information for that V-STA will not be included in the response frame; Step 4: Receive the channel reservation response frame; After receiving the channel reservation response frame from the VR-STA, if the channel reservation response frame agrees to the V-STA's channel reservation request, the V-STA records the SP information of the channel reservation and plans to communicate with the VR-STA in the SP. After receiving the channel reservation response frame from the VR-STA, the NV-STA records the SP information of the channel reservation; Step 5: SP Phase; Before the SP reservation begins, all stations must stop their current data transmission to ensure that the channel is idle when the SP starts. The NV-STA remains silent from the start of the SP for a duration specified by the silence interval, in order to avoid interfering with the scheduled transmissions of the V-STA and VR-STA. V-STA prioritizes transmitting the reserved frame types from the start of SP to ensure timely transmission of key frames and reduce the impact of latency on video quality; if the reserved frame types have been transmitted, other frame types are transmitted.

2. An electronic device, characterized in that, include: Processor and memory; The memory is used to store a computer program, and the processor is used to execute the computer program stored in the memory to cause the electronic device to perform the method as described in claim 1.

3. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by a processor, it implements the method as described in claim 1.

4. A chip, characterized in that, include: A processor for retrieving and running a computer program from memory, causing a device on which the chip is mounted to perform the method as described in claim 1.

5. A computer program product, characterized in that, The computer program product includes a computer storage medium storing a computer program, the computer program including instructions executable by at least one processor, which, when executed by the at least one processor, implement the method as described in claim 1.

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