Wireless communication method and device for augmented reality traffic

Abstract

The invention provides a wireless communication method. The method can be performed in a wireless communication device. The device configures a first enhanced configuration grant (CG) for a first uplink flow of an augmented reality (XR) service. The device configures a first downlink flow of the XR service using a first uplink flow of the XR service. The device performs an uplink transmission on the first uplink flow in accordance with the CG belonging to the first enhancement configuration grant. The device monitors the control channel to receive an uplink dynamic grant for the first uplink flow and / or a downlink dynamic allocation for the first downlink flow for a first duration after a predefined offset after the CG.

Description

Technical Field

[0001] The present invention relates to the field of communication systems, and more particularly to a wireless communication method and device for extended reality (eXtended Reality, XR) services. Background Art

[0002] The wireless communication systems of the third generation (3G) mobile phone standards and technologies are well known. Such 3G standards and technologies were developed by the Third Generation Partnership Project (3GPP). The third generation of wireless communication was developed to support macrocellular mobile phone communications, so that the communication systems and networks are moving towards broadband and mobile systems. In a cellular wireless communication system, a user equipment (UE) is connected to a radio access network (RAN) via a radio link. The RAN includes a set of base stations (BS) that provide a radio link with the UE in the cell covered by the base station and an interface to the core network (CN), the former providing a radio link with the UE in the cell covered by the base station and the latter providing overall network control. The RAN and the CN each perform their own functions related to the entire network. The Third Generation Partnership Project developed the Long Term Evolution (LTE) system, the Evolved Universal Mobile Telecommunications System Radio Access Network (E-UTRAN), for mobile access networks, in which one or more macro base stations are supported by base stations called eNodeB or eNB (evolved NodeB). LTE is further developing towards the so-called 5G or NR (New Radio) system, in which one or more cells are supported by base stations called next generation NodeB base stations (gNB). Technical issues

[0003] The 5G wireless communication system is designed to provide enhanced mobile broadband (eMBB), ultra-reliable low-latency communication (URLLC), and massive machine type communication (mMTC) services. In 5G or NR, functions supporting eMBB, URLLC, and mMTC were introduced in Release 15 and further enhanced in Releases 16 and 17.

[0004] Extended reality (XR) and cloud gaming services are important media applications supported by 5G. In a series of 3GPP research projects, it was found that XR services have some unique characteristics in traffic requirements, and the current 5G system may not be able to support XR services well. Some characteristics of XR traffic are listed below: ●Variable video frames: Video stream is the most important data stream in XR services. Video stream consists of a series of continuous video frames. Each video frame is a picture encoded / compressed using different codec mechanisms (such as H.264 / H.265 / H.266, AV1, or the audio video coding standard called AVS) for efficient storage and transmission. Generally, three main frame / picture types (i.e., I-frames, P-frames, and B-frames) are used in encoding. Even for frames of the same type, the data size of each frame is different. During transmission, a frame can basically be split into a set of data packets. However, the variable size of video frames at least results in variable data packet sizes or variable numbers of data packets for different frames. ● Real-time, high data rate, low latency: Obviously, XR service is a real-time service, and it also has the characteristics of high data rate and low latency. For potential services, the guaranteed data rate is about 100 megabits per second (Mbps), the frame rate is 60 to 120Hz, and the video resolution is 8K. The downlink (DL) data rate of UE with low latency (e.g., 2.5 milliseconds latency) can exceed 100Mbps, and the uplink (UL) data rate can be 50Mbps. For communication reliability, the packet error rate of UL transmission should be less than 10 -4 The packet error rate of DL transmission should be less than 10 -5 . ● Non-integer period: According to the XR service traffic model agreed in the Release 17 (Rel-17) XR Study Item (SI) in 3GPP RAN1, the video stream of the XR service can be configured as 30, 60, 90 or 120 frames per second (FPS). Therefore, the XR frames will arrive at the RAN quasi-periodically with a period of 1 / 60, 1 / 90 or 1 / 120 seconds, also known as a non-integer period. Semi-persistent scheduling (SPS) or configured grant (CG) for periodic traffic can reduce the control signaling overhead, which can be a good choice for providing XR traffic. However, the current configuration of the SPS / CG period cannot match the non-integer period of XR traffic. ● Jitter: Due to the different delays caused by XR data encoding, rendering and network delivery, XR traffic has a jitter effect on the arrival time of data packets. The jitter effect makes it impossible for XR traffic receiver devices (such as gNB or UE) to predict the arrival time of specific data packets. In the RAN1 XR SI study, it was decided to use a truncated Gaussian distribution to model the jitter of XR traffic. The jitter range is determined to be [-4, 4] ms (i.e. from -4ms to 4ms) as the baseline and [-5, 5] ms (i.e. from -5ms to 5ms) as the optional range. Due to the jitter problem, the configured period cannot adapt to the random jitter effect, so the performance of SPS / CG cannot well support XR services. ●Multiple data flows: According to the XR service traffic model agreed upon in Rel-17 XR Study Item (SI) in 3GPP RAN1, there are three options for the multi-flow model for downlink (DL) XR traffic: ●Option 1: I frame + P frame; ● Option 2: Video + Audio / Data; and ●Option 3: FOV + omnidirectional stream.

[0005] In option 1, I frame is called intra-coded frame or independent frame, and P frame is called predicted frame. In XR service, XR traffic of option 1 includes I frame stream and P frame stream. In option 2, video, audio, and data respectively represent video stream, audio stream, and data stream in XR traffic. In XR service, XR traffic of option 2 includes video stream and audio / data stream. In option 3, FOV represents field of vision stream (FOV) in XR traffic. In XR service, XR traffic of option 3 includes FOV stream and omnidirectional stream.

[0006] There are also three options for the multiple stream model for uplink (UL) XR traffic: ●Option 2: Gesture / control + aggregate scene, video, data and audio; ● Option 3A: Gesture / Control + Aggregate Scene and Video Streams + Aggregate Audio and Data Streams; and ●Option 3B: Gesture / Control + I-frame stream of video + P-frame stream of video.

[0007] In Option 2, Option 3A, and Option 3B of UL XR traffic, gesture / control refers to gesture and control information flows of XR traffic. The term "aggregated scene, video, data, and audio" refers to aggregated scene, video, data, and audio flows.

[0008] XR traffic has both DL and UL parts, both of which are periodic or quasi-periodic. The current specification does not have a mechanism to align uplink and downlink transmissions. In addition to waking up to receive or transmit traffic, the modem in the UE can enter a low power state to save power. If DL and UL traffic are received and transmitted at different time locations, the modem needs to wake up multiple times to process them, which requires additional state transition time and additional power. In addition, whenever there is DL or UL activity, the UE wake-up time can be extended in conjunction with the current discontinuous reception (DRX) related timer operations. Discontinuous DL and UL traffic will result in more UE wake-up time and therefore more UE power consumption.

[0009] Therefore, a method is needed to provide SPS and CG enhancements for XR services as well as dynamic scheduling / authorization enhancements. Technical Solution

[0010] The purpose of the present invention is to provide a user equipment, a base station and a wireless communication method. In a first aspect, an embodiment of the present invention provides a wireless communication method, which may be executed in a user equipment UE, including: Configuring a first enhanced configuration authorization CG for a first uplink flow, wherein the first uplink flow belongs to a first type of data flow; When there is uplink data and / or a status report of the first uplink flow to be transmitted, performing uplink transmission for the first uplink flow according to a configuration grant belonging to the first enhanced configuration grant; Monitoring a physical downlink control channel (PDCCH) to receive an uplink dynamic grant for the first uplink flow and / or a downlink dynamic allocation for the first downlink flow within a predefined offset of a first time period after a CG belonging to the first enhanced configuration grant; transmitting traffic data of the first uplink flow according to the uplink dynamic grant of the first uplink flow; and Traffic data of the first downlink flow is received according to the downlink dynamic allocation of the first downlink flow.

[0011] In a second aspect, an embodiment of the present invention provides a wireless communication device, which includes a processor, wherein the processor is configured to call and run a computer program stored in a memory so that a device on which the processor is installed executes the method disclosed by the present invention. In a third aspect, an embodiment of the present invention provides a wireless communication method, which may be performed in a base station, including: Configuring a first enhanced configuration authorization CG for a first uplink flow, wherein the first uplink flow belongs to a first type of data flow; receiving an uplink transmission comprising uplink data and / or a status report for a first uplink flow on a CG granted by a first enhanced configuration; transmitting, within a predefined offset of a first duration after the CG belonging to the first enhanced configuration grant, an uplink dynamic grant for the first uplink flow in a physical downlink control channel PDCCH based on a status report of the first uplink flow received on the CG belonging to the first enhanced configuration grant; transmitting, within a predefined offset of a first duration after the CG belonging to the first enhanced configuration grant, a downlink dynamic allocation of the first downlink flow in the PDCCH if there is downlink traffic data for the first downlink flow to be transmitted; receiving, in accordance with the uplink dynamic grant for the first uplink flow, traffic data for the first uplink flow; Traffic data of the first downlink flow is transmitted according to the downlink dynamic allocation of the first downlink flow.

[0012] In a fourth aspect, an embodiment of the present invention provides a wireless communication, including a processor, wherein the processor is configured to call and run a computer program stored in a memory so that a device on which the processor is installed executes the method disclosed by the present invention.

[0013] The method of the present invention can be implemented in a chip. The chip may include a processor configured to call and run a computer program stored in a memory so that a device equipped with the chip executes the disclosed method.

[0014] The method of the present invention can be programmed as computer-executable instructions stored in a non-transitory computer-readable medium. When the non-transitory computer-readable medium is loaded into a computer, it instructs the processor of the computer to execute the method of the present invention.

[0015] The non-transitory computer readable medium may include at least one of the following group: a hard disk, a CD-ROM, an optical storage device, a magnetic storage device, a read-only memory, a programmable read-only memory, an erasable programmable read-only memory, an EPROM, an electrically erasable programmable read-only memory, and a flash memory.

[0016] The present invention provides a computer program product, comprising a computer program, wherein the computer program enables a computer to execute the above method.

[0017] The present invention provides a computer program which enables a computer to execute the above method. Beneficial Effects

[0018] The embodiments of the present invention provide: (1) a method for aligning uplink transmission and downlink reception in XR services, which can improve NR capacity and reduce UE power consumption based on DRX functionality, and (2) A method for RAN-assisted synchronization and alignment between uplink and downlink operations in XR services to coordinate the transmission time of XR traffic at the server and client, and to help the base station gNB reduce the buffer of XR downlink flow. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative work.

[0020] Figure 1 A schematic diagram showing an example of a telecommunication system according to an embodiment of the present invention is shown.

[0021] Figure 2 A schematic diagram illustrating a network embodiment of a wireless communication method according to the present invention is shown.

[0022] Figure 3 A schematic diagram of a wireless communication method according to an embodiment of the present invention is shown.

[0023] Figure 4 FIG. 4 is a schematic diagram illustrating a wireless communication method according to another embodiment of the present invention.

[0024] Figure 5 An example of an XR service processing a data stream is shown.

[0025] Figure 6 Shows an example of an XR service that handles more data streams.

[0026] Figure 7 Another example of XR service that handles more data streams is shown.

[0027] Figure 8 The time interval T1 between every two adjacent CG opportunities, the period of the XR data packet pattern, and the period of the XR frame are shown.

[0028] Fig. 9 FIG. 1 is a schematic diagram showing a first embodiment of sharing time information for transmitting downlink traffic.

[0029] Fig.10 FIG. 4 is a schematic diagram showing a second embodiment of sharing time information for transmitting downlink traffic.

[0030] Fig.11A schematic diagram of a wireless communication system according to an embodiment of the present invention is shown. DETAILED DESCRIPTION

[0031] The embodiments of the present invention describe technical matters, structural features, implementation purposes and effects in detail with reference to the accompanying drawings. Specifically, the terms in the embodiments of the present invention are only used for the purpose of describing specific embodiments, rather than limiting the disclosure.

[0032] The present invention discloses a wireless communication method for processing extended reality (XR) traffic in an extended reality (XR) service. XR services may include augmented reality (AR), virtual reality (VR) or mixed reality (MR). User equipment

[0033] Reference Figure 1 The telecommunication system includes UE 10a, UE 10b, a base station (BS) 20a and a network entity device 30, and the telecommunication system is used to execute the method disclosed according to the embodiment of the present invention. Figure 1 This is only for illustration and not for limiting the present invention. The telecommunication system may include more UE, BS and CN entities. The connections between devices and device components are based on Figure 1 1 and 12. The UE 10a may include a processor 11a, a memory 12a, and a transceiver 13a. The UE 10b may include a processor 11b, a memory 12b, and a transceiver 13b. The base station 20a may include a processor 21a, a memory 22a, and a transceiver 23a. The network entity device 30 may include a processor 31, a memory 32, and a transceiver 33. Each processor 11a, 11b, 21a, and 31 may be configured to implement the functions, processes, and / or methods described in the embodiments of the present invention. The radio interface protocol layer may be implemented in the processors 11a, 11b, 21a, and 31. Each memory 12a, 12b, 22a, and 32 may store various programs and information to cooperate with the operation of the connected processor. Each transceiver 13a, 13b, 23a, and 33 works with the connected processor to send and / or receive radio signals or wired signals. The UE 10a may communicate with the UE 10b via a side link. The base station 20a may be an eNB, a gNB, or one of other types of radio nodes, and may configure radio resources for the UE 10a and the UE 10b.

[0034] The network entity device 30 may be a node in CN. CN may include LTE CN or 5G core network (5GC), including user plane function (UPF), session management function (SMF), 5G core access and mobility management function (AMF), unified data management (UDM), policy control function (PCF), control plane (CP) / user plane (UP) separation (CUPS), authentication server (AUSF), network slice selection function (NSSF) and network exposure function (NEF).

[0035] The UE examples described in the following embodiments may include one of UE 10a or UE 10b. The base station examples described in the following embodiments may include base station 20a. Uplink (UL) transmission of control signals or data refers to a transmission operation from a UE to a base station. Downlink (DL) transmission of control signals or data refers to a transmission operation from a base station to a UE. A downlink control signal may include downlink control information (DCI) or a radio resource control (RRC) signal from a base station to a UE.

[0036] Figure 2 It is an XR service transmission network model supported by the 5G system. UE 10 is a 5G terminal that can support XR services and XR applications, and can also be called a client, client or XR client. gNB 20 is a 5G radio node. gNB 20 communicates with UE 10 and provides NR user plane and control plane protocol terminals to UE through the NR Uu interface. gNB 20 is connected to 5GC 300 through the NG interface. AMF 30b is the AMF in 5GC 300. The XR server 41 providing XR services is located in the data network (Datanetwork, DN) 40. DN 40 can provide network operator services, Internet access or third-party services. The XR server 41 may include a processor 411, a memory 412 and a transceiver 413. The processor 411 may be configured to implement functions, processes and / or methods related to XR services. The processor 411 may implement a layer of a radio interface protocol. The memory 412 may be operable to store various programs and information to cooperate with the connected processor. The transceiver 413 works with a connected processor to send and / or receive radio signals or wired signals.

[0037] Each processor 411, 11a, 11b, 21a and 31 may include an application-specific integrated circuit (ASIC), other chipsets, logic circuits and / or data processing devices. Each memory 412, 12a, 12b, 22a and 32 may include a read-only memory (ROM), a random access memory (RAM), flash memory, a memory card, a storage medium and / or other storage devices. Each transceiver 413, 13a, 13b, 23a and 33 may include a baseband circuit and a radio frequency (RF) circuit to process radio frequency signals. When the embodiment is implemented by software, the technology described herein may be implemented by modules, processes, functions, entities, etc. that perform the functions described herein. These modules may be stored in a memory and executed by a processor. As is well known in the art, the memory may be integrated inside the processor or implemented outside the processor, and the memory may be communicatively coupled to the processor in various ways. The device that performs the wireless communication method may be a sending device that transmits the XR traffic of the XR service to a receiving device or a receiving device that receives the XR traffic. The XR traffic may include one or more XR streams of the XR service. For example, the device performing the wireless communication method may include the gNB 20, the XR server 41 in the data network 40, or the UE. That is, the XR server 41 in the data network 40 may operate as a sending device that performs the wireless communication method in certain XR traffic transmission opportunities, and the UE 10 operates as a receiving device for the XR traffic sent from the sending device. Similarly, the UE 10 may perform the wireless communication method in certain XR traffic transmission opportunities as a transmitter device, and the XR server 41 operates as a receiver device to receive the XR traffic sent from the transmitter device. Optionally, the transmitter device may include an intermediate device between the UE 10 and the XR server 41. The UE 10 may include the UE 10a or UE 10b of the embodiment of the present invention. The gNB 20 may include the base station 20a of the embodiment of the present invention. Please note that although the gNB 20 and the AMF / 5GC 30b are described as examples in the embodiment of the present invention, the wireless communication method may be performed by other types of base stations, such as another gNB, an eNB, a base station integrating an eNB and a gNB, or a base station for technologies other than 5G. AMF / 5GC 30b may include another network entity of 5GC.

[0038] One or more steps (or blocks) in the embodiments of the present invention may be implemented as a computer program, instruction, software module stored in a memory of a transmitter device, or as a circuit or hardware module in a processor of a transmitter device, or as an IC chip, circuit or plug-in of a transmitter device.

[0039] The video stream of the XR service will be quasi-periodically encoded and compressed in the form of frames, with a corresponding frame period of 1 / 60, 1 / 90 or 1 / 120 seconds. Since the transmitter device can divide the video stream of the XR service into multiple transmission units, and then encapsulate and transmit each transmission unit into a transmission data packet transmitted over the network, the transmission mechanism of the XR service is actually based on packets rather than frames. The size of each packet can be variable, the number of packets can be variable, and can be configured according to one or more parameters of QoS requirements and characteristics of the XR service, such as packet delay budget (PDB), packet error rate (PER), packet loss rate (PLR), frame error rate, frame delay budget, resolution, frame rate and / or data rate.

[0040] Reference Figure 3 and Figure 4 , UE 10 and gNB 20 execute the method disclosed in the embodiment of the present invention and start the XR service (A101 and B101).

[0041] When UE 10 performs a wireless communication method, a first enhanced configuration grant (CG) is configured for a first uplink stream of an extended reality (XR) service, wherein the first uplink stream belongs to a first type of XR stream in the XR service (A102). UE 10 configures a first downlink stream of the XR service with a first uplink stream of the XR service, wherein a period of the first downlink stream is synchronizable with a period of the first uplink stream (A103).

[0042] The gNB 20 performs a wireless communication method to configure a first enhanced configuration authorization (CG) for a first uplink flow of an extended reality (XR) service, wherein the first uplink flow belongs to a first type of XR flow in the XR service (B102). The gNB 20 configures a first downlink flow of the XR service with a first uplink flow of the XR service, wherein a period of the first downlink flow is synchronizable with a period of the first uplink flow (B103).

[0043] If there is uplink data and / or status report for the first uplink flow to be transmitted, the UE 10 performs uplink transmission for the first uplink flow belonging to the first enhanced configuration grant (A105). The uplink transmission for the first uplink flow belonging to the first enhanced configuration grant includes the transmission of a buffer status report (BSR). The gNB 20 determines whether the uplink transmission for the first uplink flow is received by the gNB 20 belonging to the first enhanced configuration grant (B105).

[0044] In a first duration predefined offset after the CG belonging to the first enhanced configuration grant, the gNB 20 transmits an uplink dynamic grant for the first uplink stream in a physical downlink control channel (PDCCH) based on a reception status report of the first uplink stream on the CG belonging to the first enhanced configuration grant. In the first duration, in a grant configured at a predefined offset after the CG belonging to the first enhanced grant, if there is downlink service data for the first downlink stream to be transmitted, the gNB 20 transmits a downlink dynamic allocation for the first downlink stream in the PDCCH (B106). In the gNB 20, the first duration is timed by a first timer of the first enhanced configuration grant. The UE 10 monitors the PDCCH to receive an uplink dynamic grant for the first uplink stream and / or a downlink dynamic allocation for the first downlink stream, at a predefined offset after the uplink transmission of the first uplink stream on the CG belonging to the first enhanced configuration grant (A106). In the UE 10, the first duration is timed by a first timer of the first enhanced configuration grant. In one embodiment, the first timer and the predefined offset may be configured in the ConfiguredGrantConfig information element, or may be configured through downlink control information (DCI) or predefined configuration. The first duration may be a portion of a discontinuous reception (DRX) activity time of the UE.

[0045] UE 10 transmits the traffic data of the first uplink flow according to the uplink dynamic grant (A108). gNB 20 receives the traffic data of the first uplink flow according to the uplink dynamic grant (B108).

[0046] The gNB 20 transmits the traffic data of the first downlink flow according to the downlink dynamic allocation (B109). The UE 10 receives the traffic data of the first downlink flow according to the downlink dynamic allocation (A109).

[0047] In one embodiment, UE 10 also configures a second enhanced configuration grant (CG) for a second uplink stream of the XR service, wherein the second uplink stream belongs to a second type of XR stream in the XR service (A102). UE 10 configures the second downlink stream of the XR service with the second uplink stream of the XR service, wherein a period of the second downlink stream can be synchronized with a period of the second uplink stream. gNB 20 also configures a second enhanced configuration grant (CG) for the second uplink stream of the XR service, wherein the second uplink stream belongs to a second type of XR stream in the XR service. gNB 20 configures the second downlink stream of the XR service with the second uplink stream of the XR service, wherein a period of the second downlink stream can be synchronized with a period of the second uplink stream.

[0048] If there is uplink data and / or status report for the second uplink flow to be transmitted, the UE 10 performs an uplink transmission for the second uplink flow on the CG that belongs to the second enhanced configuration grant. The uplink transmission of the second uplink flow on the CG that belongs to the second enhanced configuration grant includes the transmission of the buffer status report. The gNB 20 receives the uplink transmission of the second uplink flow on the CG that belongs to the second enhanced configuration grant.

[0049] During a second duration after the CG belonging to the second enhanced configuration authorization, the gNB 20 transmits an uplink dynamic grant for the second uplink flow in a physical downlink control channel (PDCCH) based on a reception status report of the second uplink flow on the CG belonging to the second enhanced configuration authorization; within a predefined offset of the second duration after the CG belonging to the second enhanced configuration authorization, if there is downlink traffic data of the second downlink flow to be transmitted, the gNB 20 transmits a downlink dynamic allocation for the second downlink flow in the PDCCH. In the gNB 20, the second duration is timed by a second timer of the second enhanced configuration authorization. The UE 10 monitors the PDCCH to receive an uplink dynamic grant for the second uplink flow and / or a downlink dynamic allocation for the second downlink flow, a predefined offset after the uplink transmission of the second uplink flow on the CG belonging to the second enhanced configuration authorization. In the UE 10, the second duration is timed by a second timer of the second enhanced configuration authorization. In one embodiment, the second timer and the predefined offset may be configured in the ConfiguredGrantConfig information element, or may be configured through downlink control information (DCI) or predefined configuration. The second duration may be a portion of a discontinuous reception (DRX) activity time of the UE.

[0050] UE 10 transmits the traffic data of the second uplink flow according to the uplink dynamic grant. gNB 20 receives the traffic data of the second uplink flow according to the uplink dynamic grant.

[0051] The gNB 20 transmits the service data of the second downlink flow according to the downlink dynamic allocation. The UE 10 receives the traffic data of the second downlink flow according to the downlink dynamic allocation.

[0052] In one embodiment, gNB 20 configures semi-persistent scheduling (SPS) for a second downlink flow, wherein the second downlink flow belongs to a data flow of the second type. gNB 20 traffic data for the second downlink flow is based on the semi-persistently scheduled SPS. UE 10 receives traffic data for the second downlink flow on the semi-persistently scheduled SPS.

[0053] In one embodiment, UE 10 configures a normal configuration grant for a third uplink flow of an XR service, wherein the third uplink flow belongs to a third type of XR flow in the XR service. UE 10 performs an uplink transmission for the third XR flow on a CG belonging to the normal configuration grant. gNB 20 configures a normal configuration grant for the third uplink flow of the XR service. gNB 20 receives an uplink transmission of the third XR flow on the CG belonging to the normal configuration grant.

[0054] In one embodiment, the UE 10 transmits time information for transmitting the downlink traffic in the first downlink flow to the XR server. The time information may include one or more of the following information: The estimated transmission delay from the XR server to the base station serving the UE; = time information of downlink radio resources allocated for transmission of downlink traffic in the first downlink flow; and • A better start time at the server for the downlink traffic in the first downlink flow.

[0055] In one embodiment, the time information is obtained from a configuration message sent by the base station.

[0056] In one embodiment, the time information is derived from time information of downlink radio resources allocated for transmission of the downlink traffic in the first downlink flow.

[0057] In one embodiment, the UE sends an initial preferred start time to the base station and receives a start time determined by the base station as a preferred start time for downlink traffic in the first downlink flow. The gNB 20 may determine the start time as the preferred start time for downlink traffic in the first downlink flow based on the initial preferred start time received from the UE 10.

[0058] In one embodiment, the start time determined by the base station is carried by a CG activation message of the CG or a radio resource control (RRC) configuration message of the CG. Transmission alignment between uplink and downlink in RAN:

[0059] Considering the characteristics of XR traffic, in particular: ■ Variable video frames, high data rates, and strong periodicity: Although the video traffic of XR services is periodic or quasi-periodic, the current CG and SPS methods based on semi-static configuration of fixed periodicity and grant size are obviously insufficient to support XR traffic with variable and high data rate characteristics. ■ Jitter: For the downlink, jitter will cause the gNB 20 to be unable to predict the arrival time of a specific data packet. ■ Bidirectional: For uplink, the packet burst time of video frames is predictable because the data generated on the UE side has no jitter and transmission delay.

[0060] In addition, the DRX function is one of the basic configurations for achieving UE energy saving in the RRC connected state. In order to support XR services with lower UE power consumption, a method for uplink and downlink transmission alignment is now disclosed, as shown below. The downlink traffic or uplink traffic in the description may be downlink traffic or uplink traffic of one or more streams belonging to the XR service, and the traffic data in the description may be traffic data of one or more streams belonging to the XR service. The traffic data of the XR service is transmitted via the physical uplink shared channel (PUSCH).

[0061] For gNB: ■gNB 20 is configured with a buffering function for downlink traffic. ■gNB 20 configures one or more enhanced CGs for UE 10 for each enhanced CG. ●The gNB 20 configures the duration and time offset for the UE 10 so that the UE 10 monitors the PDCCH to receive subsequent uplink dynamic grants (or dynamic plans) and / or downlink dynamic allocations (or dynamic plans) in the RRC connected state according to the duration and time offset. ■gNB 20 configures zero or one normal CG and / or SPS, the definitions of which are the same as those in the current 3GPP specifications for UE 10. ■For each enhanced CG opportunity, wait for a period of time defined by the time offset after the transmission of XR traffic in the CG opportunity: ● If gNB 20 receives an uplink scheduling request from UE 10 within the duration, gNB 20 sends an uplink dynamic grant to UE 10; and / or ●If downlink service data is to be transmitted within the duration, gNB 20 transmits the downlink dynamic allocation to UE 10. ■gNB 20 transmits downlink traffic data on PDSCH according to downlink dynamic allocation. ■gNB 20 receives uplink traffic data on PUSCH based on the uplink dynamic grant. ■ If one or more normal SPSs are configured, the gNB 20 transmits downlink traffic data to the UE 10 via the one or more normal SPSs according to procedures in the current 3GPP standards; ■ If one or more normal CGs are configured, the gNB 20 receives uplink traffic data from the UE 10 by one or more normal CGs according to procedures in the current 3GPP standard;

[0062] For UE10: ■ For each enhanced CG, the UE 10 receives one or more CGs as enhanced CGs to the UE 10: ● receiving a duration and a time offset of the UE 10 so that the UE 10 monitors the PDCCH to receive a subsequent uplink dynamic grant (or dynamic schedule) and / or a downlink dynamic allocation (or dynamic schedule) in an RRC connected state according to the duration and the time offset; ■UE 10 receives zero or one normal CG and / or SPS configurations of gNB 20, which are defined as in the current 3GPP specifications. ■For each Enhanced CG opportunity: ● In an attempt to send a scheduling request, the UE 10 transmits an uplink scheduling request to the gNB 20 on the enhanced CG; and ● After waiting for a period of time defined by the time offset after the XR traffic transmission in the CG event, the UE 10 starts monitoring the PDCCH for the duration ■If the BSR was transmitted in the previous enhanced CG, the UE 10 receives the uplink dynamic grant and transmits the uplink traffic data on the PUSCH according to the uplink dynamic grant. ■ If an uplink dynamic grant is received, the UE 10 transmits uplink traffic data on the PUSCH according to the uplink dynamic grant. ■ If a downlink dynamic allocation is received, the UE 10 receives downlink traffic data on the PDSCH according to the downlink dynamic allocation. ■ If one or more normal CGs are configured, the UE 10 transmits uplink traffic data to the gNB 20 via the one or more normal CGs according to the procedures in the current 3GPP standards; ■ If one or more normal SPSs are configured, the UE 10 receives downlink traffic data from the gNB 20 by the one or more normal SPSs according to procedures in the current 3GPP standard; ■The downlink dynamic assignment may include radio resources for PDSCH transmission in one or more time domains, and the gNB 20 may send one or more transport blocks (TBs) to the UE 10 through the downlink dynamic assignment. ■The uplink dynamic grant may include one or more radio resources in the time domain for PUSCH transmission, and the UE 10 may send one or more transport blocks (TBs) to the gNB 20 through the uplink dynamic grant.

[0063] The following are some embodiments of combining the method of the present invention with the DRX function based on XR service traffic.

[0064] Embodiment 1:

[0065] In this embodiment, only one CG (e.g., CG1) is configured as an enhanced CG for XR traffic transmission, and a timer is configured for the enhanced CG. ■The uplink traffic of XR services consists of only one stream with a variable data rate; and ■The downlink traffic for XR services consists of only one variable data rate stream.

[0066] In the example of a single stream model of AR UL / DL in the XR service traffic model agreed in Rel 17XRSI in 3GPP RAN1, stream 1 may be a stream for attitude / control, and stream 2 may be a stream for aggregated scenes, video, data, and audio. Please note that this embodiment is not limited to the example, and the stream may be set according to another option in the two stream models.

[0067] like Figure 5 As shown, in the basic configuration of this embodiment, the disclosed method includes a data transmission procedure including the steps. These steps are not limited to the specific order described. The axis t in the figure represents the time domain. 1. gNB 20 configures a buffer function for downlink traffic. 2.gNB 20 configures enhanced CG1 for UE 10. ●gNB 20 configures a duration counted by a timer. For CG1, gNB 20 can configure a value as the initial value of the timer subsequentDynamicTimer. ●gNB 20 configures a time offset, called the “predefined offset” of CG1. • The time offset can be 0, 1 or more and is measured in time units such as symbols, slots, subslots, minislots or milliseconds. 3. For each CG1 opportunity: ● To send a BSR, UE 10 transmits the BSR to gNB 20 on CG1. The BSR may include an enhanced BSR. Figure 5 As shown, BSR is sent at opportunities 1, 2 and 4, while BSR is not sent at opportunity 3. ●After waiting for the time period defined by the time offset "Predefined offset": The UE 10 starts monitoring the PDCCH until the timer subsequent to the DynamicTimer expires. If gNB 20 receives an uplink scheduling request from UE 10 on the enhanced CG, gNB 20 transmits an uplink dynamic grant (DG1 for short) to UE 10 on PDCCH during the execution of the timer subsequentDynamicTimer. Figure 5 As shown, gNB 20 sends an uplink dynamic grant of BSR to UE 10 at opportunities 1, 2, and 4, but does not send an uplink dynamic grant to UE 10 at opportunity 3 because no BSR is sent to gNB 20 between opportunities 2 and 3. If downlink traffic data is to be transmitted while the timer subsequentDynamicTimer is running, the gNB 20 transmits a downlink dynamic allocation (DA1) to the UE 10 on the PDCCH. Figure 5 As shown, gNB 20 sends downlink dynamic allocation to UE 10 at opportunities 1, 2 and 3, and does not send downlink dynamic allocation to UE 10 at opportunity 4. 4. UE 10 transmits uplink traffic data for XR service received by gNB 20 on PUSCH according to the uplink dynamic grant on PDCCH. 5.UE 10 receives the downlink traffic data of the XR service on PDSCH, and gNB 20 sends the downlink traffic data of the XR service according to the downlink dynamic allocation on PDCCH. Embodiment 2:

[0068] In this embodiment, three CGs are configured for XR traffic transmission; CG1 and CG3 are configured as normal CGs; CG2 is configured as an enhanced CG, and a timer is configured for CG2. This embodiment is applicable to the following situations:

[0069] The uplink traffic of the XR service has three data flows, including the first uplink flow U1, the second uplink flow U2 and the third uplink flow U3. ●The three data streams have different periods; ● The first uplink flow U1 has a stable data rate; • the second uplink flow U2 has a variable data rate; and • The third uplink flow U3 has a stable data rate.

[0070] The downlink traffic of the XR service has two data flows, including a first downlink flow D1 and a second downlink flow D2. ●The two data streams have different periods; • the first downlink flow D1 has a variable data rate; and • The second downlink flow D2 has a stable data rate.

[0071] The period of the second uplink flow U2 is the same as or similar to the period of the first downlink flow D1.

[0072] The period of the third uplink flow U3 is the same as or similar to the period of the second downlink flow D2.

[0073] Table 1 illustrates the association between uplink and downlink flows, the association between uplink flows and CGs, and the association between downlink flows and downlink radio resources (such as DA or SPS). Table 1

[0074] In the example of three stream model 3A for AR UL in the traffic model agreed upon for XR service business as agreed upon in Rel 17XRSI in reference to 3GPP RAN1, the first uplink stream U1 may be a stream for attitude / control, the second uplink stream U2 may be a stream for aggregated scene and video streams, and the third uplink stream U3 may be a stream for aggregated audio and data streams. In the example of dual stream model option 2 with reference to AR DL, the first downlink stream D1 may be a video stream, and the second downlink stream D2 may be an audio / data stream. Please note that this embodiment is not limited to the example, and the streams may be set according to another option in the above stream model.

[0075] like Figure 6 As shown, in the basic configuration of this embodiment, the method disclosed by the present invention includes a data transmission procedure including steps. These steps are not limited to the specific order described in the specification. 1. gNB 20 configures a buffer function for downlink traffic including the first downlink flow D1. 2. gNB 20 configures CG1 and CG3 as normal CGs for the first uplink flow U1 and the third uplink flow U3, respectively, and configures CG2 as an enhanced CG for the second uplink flow U2 to UE 10. For enhanced CG2: The gNB 20 configures the duration timed by the timer, called subsequentDynamicTimer for CG2. The gNB 20 may configure a value as the initial value of the timer subsequentDynamicTimer; ●gNB 20 is configured with a time offset, called the “predefined offset” of CG2. • The time offset can be 0, 1 or greater, in time units such as symbols, slots, subslots, minislots or milliseconds. 3. gNB 20 configures a normal SPS (referred to as SPS1) for the second downlink flow D2 to UE 10. ●The period of SPS1 is the same as or similar to that of CG3. ● For frequency division duplex (FDD) mode, the opportunity of SPS1 is the same as or as close as possible to the CG opportunity of CG3. For time division duplex (TDD) mode, the opportunity of SPS1 is as close as possible to the CG opportunity of CG3. 4. For each periodic or quasi-periodic CG2 opportunity with period P2: ● If a BSR for the second uplink flow U2 is to be transmitted, the UE 10 transmits the BSR to the gNB 20 on CG2. The BSR may include an enhanced BSR. Figure 6 As shown, BSR is sent at opportunities 1, 2 and 4, while no BSR is sent between opportunity 2 and opportunity 3. ●After waiting for the time period defined by the time offset "Predefined offset": UE 10 starts monitoring the PDCCH until the timer subsequentDynamicTimer expires. For the second uplink flow U2, if gNB 20 receives a BSR from UE 10 on enhanced CG2 while timer subsequentDynamicTimer is running, gNB 20 transmits an uplink dynamic grant (referred to as DG2) to UE 10 on PDCCH. Figure 6 As shown, gNB 20 sends an uplink dynamic grant of BSR to UE 10 at opportunities 1, 2, and 4, but does not send an uplink dynamic grant to UE 10 at opportunity 3 because no BSR is sent between opportunity 2 and opportunity 3. For the first downlink flow D1, if downlink traffic data of the first downlink flow D1 is to be transmitted during the timer subsequentDynamicTimer is running, the gNB 20 transmits a downlink dynamic allocation (referred to as DA2) to the UE 10 on the PDCCH. Figure 6 As shown, gNB 20 sends downlink dynamic assignment to UE 10 at opportunities 1, 3 and 4, but does not send downlink dynamic assignment to UE 10 at opportunity 2. 5. UE 10 transmits uplink traffic data of the second uplink flow U2 on PUSCH according to the uplink dynamic grant for the second uplink flow U2 on PDCCH, and gNB 20 receives the data. 6.gNB 20 receives the downlink traffic data of the first downlink flow D1 on the PDSCH according to the downlink dynamic allocation of the first downlink flow D1 on the PDCCH. 7.UE 10 transmits the uplink traffic data of the first uplink flow U1 on CG1 periodically with a period P1 or a quasi-periodic period, and gNB 20 sends with a period P1. 8.UE 10 transmits the uplink traffic data of the third uplink flow U3 on CG3 periodically with a period P3 or a quasi-periodic period, and gNB 20 sends with a period P3. 9.gNB 20 periodically sends through SPS1 with a period P3 or quasi-periodically, and UE 10 receives the downlink service data of the second downlink flow D2. Example 3

[0076] In this embodiment, three CGs are configured for XR traffic transmission. CG1 and CG3 are configured as normal CGs. CG2 is configured as an enhanced CG, and a timer is configured for CG2. This embodiment is applicable to the following situations:

[0077] The uplink traffic of the XR service has three flows, including a first uplink flow U11, a second uplink flow U12, and a third uplink flow U13. ●The three data streams have different periods; ● The first uplink flow U11 has a stable data rate; • the second uplink flow U12 has a variable data rate; and • The third uplink flow U13 has a variable data rate.

[0078] The downlink traffic of the XR service has two flows, including a first downlink flow D11 and a second downlink flow D12, where ●The two data streams have different periods; • the first downlink flow D11 has a variable data rate; and • The second downlink flow D12 has a variable data rate.

[0079] The period of the second uplink flow U12 is the same as or similar to the period of the first downlink flow D11.

[0080] The period of the third uplink flow U13 is the same as or similar to the period of the second downlink flow D12.

[0081] Table 2 illustrates the association between uplink and downlink flows, the association between uplink flows and CGs, and the association between downlink flows and downlink radio resources (such as DA or SPS). Table 2

[0082] In the example of the three-stream model 3A for AR UL in the traffic model for the XR service business agreed in Rel 17XRSI in reference to 3GPP RAN1, the first uplink stream U11 can be a posture / control stream, the second uplink stream U12 can be an I stream for video, and the third uplink stream U13 can be a P stream for video. The dual-stream model option 1 is used for AR DL, where the first downlink stream D11 is an I stream for video and the second downlink stream D12 can be a P stream for video. Please note that this embodiment is not limited to the example, and the streams can be set according to another option in the above-mentioned stream model.

[0083] like Figure 7 As shown, in the basic configuration of this embodiment, the disclosed method includes a data transmission procedure including steps. These steps are not limited to the specific order described. 1.gNB 20 configures a buffer function for the first downlink flow D11 and the second downlink flow D12. 2. gNB 20 configures CG1 as the normal CG for the first uplink flow U11, CG2 as the enhanced CG for the second uplink flow U12, and CG3 as the enhanced CG for the third uplink flow U13 to UE 10. For each enhanced CG: gNB 20 configures the duration of timer subsequentDynamicTimer1. For CG2, gNB 20 may configure a value as the initial value of timer subsequentDynamicTimer1. gNB 20 configures a time offset called “predefined offset 1” for CG2; The gNB 20 configures a duration to be set by the timer subsequentDynamicTimer2. For CG3, the gNB 20 may configure a value as the initial value of the timer subsequentDynamicTimer2. ●gNB 20 configures a time offset, which for CG3 is called “predefined offset 2”; and ●the time offset can be 0, 1 or greater, in time units, such as symbols, time slots, sub-time slots, mini-time slots or milliseconds. 3. For each periodic or quasi-periodic CG2 opportunity with period P2: ● If a BSR for the second uplink flow U12 is to be transmitted, the UE 10 transmits the BSR to the gNB 20 on CG2. The BSR may include an enhanced BSR. Figure 7 As shown, BSR is sent at opportunities 21, 23 and 24, while no BSR is sent at opportunity 22. ●After waiting for the period of time defined by the time offset "Predefined offset1": UE 10 starts monitoring the PDCCH until the timer subsequentDynamicTimer1 expires. For the second uplink flow U12, if gNB 20 receives a BSR from UE 10 on enhanced CG2 while timer subsequentDynamicTimer1 is running, gNB 20 transmits an uplink dynamic grant (referred to as DG2) to UE 10 on PDCCH. Figure 7 As shown, gNB 20 sends an uplink dynamic grant of BSR to UE 10 at opportunities 21, 23, and 24, and does not send an uplink dynamic grant to UE 10 at opportunity 22 because no BSR is sent between opportunity 21 and opportunity 22. For the first downlink flow D11, if downlink traffic data of the first downlink flow D11 is to be transmitted during the timer subsequentDynamicTimer1 is running, the gNB 20 transmits a downlink dynamic assignment (referred to as DA2) to the UE 10 on the PDCCH. Figure 7 As shown, gNB 20 sends downlink dynamic allocation to UE 10 at opportunities 22 and 24, and does not send downlink dynamic allocation to UE 10 at opportunities 21 and 23. 4. UE 10 transmits uplink flow data of the second uplink flow U12 on PUSCH according to the uplink dynamic grant for the second uplink flow U12 on PDCCH, and gNB 20 receives the data. 5. The gNB 20 sends the downlink traffic data of the first downlink flow D11 on the PDSCH according to the downlink dynamic allocation of the first downlink flow D11 on the PDCCH, and the UE 10 receives the downlink traffic data of the first downlink flow D11. 6. For each periodic or quasi-periodic CG3 opportunity with a period of P3: ● If a BSR for the third uplink flow U13 is to be transmitted, the UE 10 transmits the BSR to the gNB 20 on CG3. The BSR may include an enhanced BSR. Figure 7 As shown, a BSR is sent at opportunity 31, but not at opportunity 32. ● After waiting for a period of time defined by the time offset "Predefined offset2": UE 10 starts monitoring the PDCCH until the timer followsequentDynamicTimer2 expires. For the third uplink flow U13, if gNB 20 receives a BSR from UE 10 on enhanced CG3 while timer subsequentDynamicTimer2 is running, gNB 20 transmits an uplink dynamic grant (called DG3) to UE 10 on PDCCH. Figure 7 As shown, gNB 20 sends an uplink dynamic grant to UE 10 for BSR at opportunity 31, but does not send an uplink dynamic grant to UE 10 at opportunity 32 because no BSR is sent between opportunity 31 and opportunity 32. For the second downlink flow D12, if downlink traffic data of the second downlink flow D12 is to be transmitted during the timer subsequentDynamicTimer2 is running, the gNB 20 transmits a downlink dynamic allocation (DA3) to the UE 10 on the PDCCH. Figure 7 As shown, gNB 20 sends downlink dynamic allocation to UE 10 at opportunity 32 and does not send downlink dynamic allocation to UE 10 at opportunity 31. 7. UE 10 transmits, and gNB 20 receives the uplink traffic data of the third uplink flow U13 on PUSCH according to the uplink dynamic grant for the third uplink flow U13 on PDCCH. 8. gNB 20 sends downlink traffic data of the second downlink flow D12 on PDSCH according to the downlink dynamic allocation of the second downlink flow D12 on PDCCH, and UE 10 receives the data. 9.UE 10 transmits the uplink traffic data of the first uplink flow U11 on CG1 periodically with a period P1 or a quasi-periodic period, and gNB 20 sends with a period P1. Enhanced CG configuration: For the configuration of enhanced CG, an additional timer can be introduced compared to the configuration of normal CG defined in the current 3GPP specification, according to which the UE 10 can monitor the PDCCH to receive subsequent uplink dynamic grants after the CG event is in the RRC connected state. In addition, a predefined time offset between the last symbol of the enhanced CG and the first symbol in the timer timing duration can be configured at the same time. Although the timer and time offset are named "subsequentDynamicTimer" and "subsequentDynamicOffset", they can be named by other terms. An example of the configuration of the enhanced CG is shown below, where the timer "subsequentDynamicTimer" is embodied as the field subsequentDynamicTimer-r18, and the time offset "subsequentDynamicOffset" is embodied as the field subsequentDynamicOffset-r18. Table 3: ConfiguredGrantConfig information elements Enhanced CG cycle:

[0084] For XR traffic with multiple streams in an XR service, each stream may have a different period. A stream that aggregates one or more video streams may have a non-integer period. For streams with non-integer periods, an embodiment of configuring a grant (CG) period is as follows: First solution:

[0085] like Figure 8 As shown, gNB 20 configures a mode for CG. In the mode, p1 is the frame period of the video stream, and p2 is the period of the mode;

[0086] gNB 20 configures parameter K so that: p2=K*p1, where p2 is an integer period, which can match the configuration parameters of the grant (CG) configured in the current 3GPP specification, where K is an integer.

[0087] The gNB 20 configures the time interval T1 between every two adjacent CG opportunities in a pattern such that: p2 = M*T1, where T1 is an integer duration, which may match the configuration parameters of the grant (CG) configured in the current 3GPP specification, where M is an integer.

[0088] If M is greater than 1, multiple T1s are configured and the length of each T1 may be different. However, the total length of M*T1 should be equal to p2. Second option:

[0089] gNB 20 configures an integer period (p1) for the CG, which can match the configuration parameters of the authorization (CG) configured in the current 3GPP specification.

[0090] For every N CGs, gNB 20 dynamically changes the period of a CG by transmitting downlink control information (DCI) on PDCCH, so that the change p1 and period (p2) of N CGs are integer periods, which can match the configuration parameter a of the configuration grant (CG) in the current 3GPP specification. The third option:

[0091] gNB 20 configures an integer period (p1) for the CG, which can match the configuration parameters of the authorization (CG) configured in the current 3GPP specification.

[0092] In every N CGs, the period of one CG can be changed by the offset configured in the radio resource control (RRC) message, so the change p1 and period (p2) of N CGs are integer periods that can match the configuration parameters of the authorization (CG) configured in the current 3GPP specification. RAN assisted synchronization and alignment between uplink and downlink XR streams

[0093] On the one hand, the radio resources used for XR traffic transmission in the RAN are managed and allocated by the RAN. On the other hand, the XR traffic data is generated and delivered from an application server (e.g., XR server 41) or an XR client (e.g., XR client 42) running in the UE 10. Transmitting non-aligned uplink and downlink traffic in the RAN will require more UE wake-up time, and therefore consume more UE power. Synchronizing and aligning the uplink and downlink XR streams of the XR stream is very helpful for the alignment of uplink and downlink transmissions in the RAN. A method for helping an XR server (e.g., XR server 41) and a client to synchronize and align uplink and downlink XR streams is disclosed below. The downlink traffic or uplink traffic in the description may be downlink traffic or uplink traffic in one or more streams belonging to the XR service, and the traffic data in the description may be traffic data of one or more streams belonging to the XR service. For example, the downlink traffic data in this embodiment includes one or more downlink stream data in the first downlink stream D1, the first downlink stream D11, and the second downlink stream D12.

[0094] In the first method, if Fig. 9 As shown:

[0095] The gNB 20 allocates aligned uplink and downlink radio resources for transmitting uplink and downlink traffic of the XR service in response to a request (C10), such as a "PDU session resource setup request" message or a "PDU session resource modification request" message received from an AMF (e.g., AMF 30b). In particular, the gNB 20 allocates uplink radio resources for the uplink traffic of the XR service and downlink radio resources for the downlink traffic of the XR service, wherein the uplink radio resources may be aligned with the downlink radio resources according to the above-mentioned embodiments. Please note that each "PDU session resource setup request" or "PDU session resource modify request" message may be modified or replaced by other messages having similar functions.

[0096] The gNB 20 provides the allocated aligned uplink and downlink radio resources to the UE 10 in the RRC reconfiguration procedure, wherein additional timing information for transmitting downlink traffic may also be transmitted to the UE 10 (C12). The timing information for transmitting downlink traffic may be one or more of the following information: ● Estimated transmission delay time from an XR server (e.g., XR server 41) to a base station (e.g., gNB 20); ● time information of downlink radio resources allocated for transmission of downlink traffic; and ●Optimal start time for downlink traffic on the server.

[0097] For a CG that needs to be activated, UE 10 may send an initial preferred start time (C14) to gNB 20, and gNB 20 may determine a start time based on the initial preferred start time and use the determined start time as the preferred start time for downlink traffic to UE 10 through CG activation of the CG (C16). Alternatively, the determined start time may be transmitted in a radio resource control (RRC) configuration message of the CG.

[0098] The UE 10 transmits the time information through the application message in order to transmit the downlink traffic to the XR server.

[0099] In one embodiment, the time information for transmitting downlink traffic can be obtained from the configuration message sent from gNB 20.

[0100] In one embodiment, the time information for transmitting the downlink traffic may be derived from the time information of the downlink radio resources allocated for transmitting the downlink traffic.

[0101] In one embodiment, the time information used to transmit the downlink traffic may include one or more of the following information: The estimated transmission delay time from the XR server to the base station (e.g., gNB 20); ● time information of downlink radio resources allocated for transmission of downlink traffic; and ●Optimal start time for downlink traffic on the server.

[0102] In the second method, if Fig.10 As shown:

[0103] The gNB 20 allocates aligned uplink and downlink radio resources for transmitting uplink and downlink traffic of the XR service in response to a request (D10), such as a "PDU session resource setup request" message or a "PDU session resource modification request" message received from an AMF (e.g., AMF 30b). In particular, the gNB 20 allocates uplink radio resources for the uplink traffic of the XR service and downlink radio resources for the downlink traffic of the XR service, wherein the uplink radio resources may be aligned with the downlink radio resources according to the above-mentioned embodiments. Please note that each "PDU session resource setup request" or "PDU session resourcemodify request" message may be modified or replaced by other messages having similar functions.

[0104] The gNB 20 provides the UE 10 with allocated aligned uplink and downlink radio resources in the RRC reconfiguration procedure (D12).

[0105] For a CG that needs to be activated, UE 10 may transmit an initial preferred start time to gNB 20 (D14), and gNB 20 may determine a start time based on the initial preferred start time and use the determined start time as the preferred start time for downlink traffic to UE 10 through CG activation of the CG (D16). Alternatively, the determined start time may be transmitted in a radio resource control (RRC) configuration message of the CG.

[0106] The gNB 20 transmits the time information (D18) of transmitting the downlink traffic to the AMF through the "PDU Session Resource Setup Response" message or "PDU Session Resource Modification Response" message or other messages in the NG-AP protocol. The time information of transmitting the downlink traffic may include one or more of the following information: The estimated transmission delay from the XR server to the gNB 20; ● time information of downlink radio resources allocated for transmission of downlink traffic; and ●Optimal start time for downlink traffic on the server.

[0107] The AMF directly or indirectly transmits the time information (D19) for transmitting downlink traffic to the XR server.

[0108] If the XR client and XR server transmit traffic data according to the preferred time from the gNB 20, the downlink data can arrive at the gNB 20 while being better aligned with the uplink data so that the gNB 20 can schedule radio resources to transmit the aligned uplink and downlink traffic with a smaller downlink data buffer.

[0109] In addition, the gNB 20 can stagger the XR traffic data transmission between UEs in the cell by allocating different aligned uplink and downlink radio resources to the UEs in the time domain. Therefore, embodiments of the method of the present invention can improve the capacity of the cell for XR services and save the power of the UE 10.

[0110] Fig.11 7 is a block diagram of an example system 700 for wireless communications according to an embodiment of the present invention. The embodiments described herein may be implemented into a system using any suitably configured hardware and / or software. Fig.11 The illustrated system 700 includes a radio frequency (RF) circuit 710, a baseband circuit 720, a processing unit 730, a memory / storage 740, a display 750, a camera 760, a sensor 770, and an input / output (I / O) interface 780, which are coupled to each other.

[0111] Processing unit 730 may include circuitry such as, but not limited to, one or more single-core or multi-core processors. The processor may include any combination of general-purpose processors and special-purpose processors, such as a graphics processor and an application processor. The processor may be coupled to a memory / storage and configured to execute instructions in the memory / storage to enable various applications and / or operating systems running on the system.

[0112] Radio control functions may include, but are not limited to, signal modulation, encoding, decoding, radio frequency shifting, etc. In some embodiments, the baseband circuit may provide communications compatible with one or more radio technologies. For example, in some embodiments, the baseband circuit may support communications with 5G NR, LTE, Evolved Universal Terrestrial Radio Access Network (EUTRAN) and / or other wireless metropolitan area networks (WMAN), wireless local area networks (WLAN), and wireless personal area networks (WPAN). An embodiment in which the baseband circuit is configured to support radio communications of multiple wireless protocols may be referred to as a multi-mode baseband circuit. In various embodiments, the baseband circuit 720 may include circuits for operating signals that are not strictly considered to be in the baseband frequency. For example, in some embodiments, the baseband circuit may include circuits for operating signals with an intermediate frequency, which is between the baseband frequency and the radio frequency.

[0113] In various embodiments, system 700 may be a mobile computing device, such as, but not limited to, a laptop computing device, a tablet computing device, a netbook, an ultrabook, a smart phone, etc. In various embodiments, the system may have more or fewer components, and / or different architectures. Where appropriate, the methods described herein may be implemented as a computer program. The computer program may be stored on a storage medium, such as a non-transitory storage medium.

[0114] Embodiments of the present invention are a combination of techniques / processes that may be adopted in 3GPP specifications to create a final product.

[0115] If the software functional unit is implemented and used and sold as a product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution proposed in the present invention can be implemented basically or partially in the form of a software product. Alternatively, part of the technical plan is beneficial to conventional technology and can be implemented in the form of a software product. The software product is stored in a storage medium in a computer, including multiple commands for a computing device (such as a personal computer, a server, or a network device) to run all or part of the steps disclosed in the embodiment of the present invention. The storage medium includes a USB disk, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a floppy disk, or other medium capable of storing program code.

[0116] While the present invention has been described in connection with what is considered to be the most practical and preferred embodiment, it is to be understood that the invention is not limited to the disclosed embodiment but is intended to cover various arrangements made without departing from the broadest interpretation of the appended claims.

Claims

1. A wireless communication method, which may be performed in a user equipment UE, comprising: Configuring a first enhanced configuration authorization CG for a first uplink flow, wherein the first uplink flow belongs to a first type of data flow; When there is uplink data and / or a status report of the first uplink flow to be transmitted, performing uplink transmission for the first uplink flow according to a configuration grant belonging to the first enhanced configuration grant; Monitoring a physical downlink control channel (PDCCH) to receive an uplink dynamic grant for the first uplink flow and / or a downlink dynamic allocation for the first downlink flow within a predefined offset of a first duration after a CG belonging to the first enhanced configuration grant; transmitting traffic data of the first uplink flow according to the uplink dynamic grant of the first uplink flow; and Traffic data of the first downlink flow is received according to the downlink dynamic allocation of the first downlink flow.

2. The wireless communication method according to claim 1, characterized in that: The first downlink flow is configured to use the first enhanced configuration grant, wherein the first downlink flow may be synchronized with a period of the first uplink flow.

3. The wireless communication method according to claim 1, characterized in that: The status report in the uplink transmission comprises a buffer status report BSR.

4. The wireless communication method according to claim 1, characterized in that: The first duration is counted by a first timer of the first enhanced configuration authorization.

5. The wireless communication method according to claim 4, characterized in that: The first timer and / or the predefined offset are configured in the ConfiguredGrantConfig information element or in the downlink control information DCI or are predefined.

6. The wireless communication method according to claim 1, characterized in that: The first duration is an active time of a portion of the discontinuous reception (DRX) of the UE.

7. The wireless communication method according to claim 1, characterized in that: Also includes: Configuring a second enhanced configuration authorization CG for a second uplink flow, wherein the second uplink flow belongs to a second type of data flow; When there is uplink data and / or a status report of the second uplink flow to be transmitted, performing uplink transmission for the second uplink flow according to the configuration grant belonging to the second enhanced configuration grant; Monitoring a physical downlink control channel (PDCCH) to receive an uplink dynamic grant for the second uplink flow and / or a downlink dynamic allocation for the second downlink flow within a predefined offset of a second duration after an uplink transmission of the CG belonging to the second enhanced configuration grant; transmitting traffic data of the second uplink flow according to the uplink dynamic grant of the second uplink flow; and Traffic data of the second downlink flow is received according to the downlink dynamic allocation of the second downlink flow.

8. The wireless communication method according to claim 7, characterized in that: The second downlink flow is configured to use the second enhanced configuration grant, wherein the second downlink flow may be synchronized with a period of the second uplink flow.

9. The wireless communication method according to claim 7, characterized in that: The second duration is counted by a second timer of the second enhanced configuration authorization.

10. The wireless communication method according to claim 7, characterized in that: The second duration is an active time of a portion of the discontinuous reception (DRX) of the UE.

11. The wireless communication method according to claim 1, characterized in that: Also includes: configuring a normal configuration grant for a third uplink flow, wherein the third uplink flow belongs to a data flow of a third type; as well as Uplink transmission is performed for the third uplink flow according to the configuration grant that belongs to the normal configuration grant.

12. The wireless communication method according to claim 1, characterized in that: Also includes: Configuring a semi-persistent scheduling SPS for a second downlink flow, wherein the second downlink flow belongs to a data flow of a second type; as well as The traffic data of the second downlink flow is received on the SPS belonging to the semi-persistent scheduling.

13. The wireless communication method according to claim 1, characterized in that: Also includes: Transmission time information, used to transmit the downlink service in the first downlink flow to the server, wherein the time information includes one or more of the following information: an estimated transmission delay time from the server to a base station serving the UE; time information of downlink radio resources allocated for transmitting said downlink traffic in said first downlink flow; and A preferred start time for downlink traffic in the first downlink flow at the server.

14. The wireless communication method according to claim 13, characterized in that: The time information is obtained from a configuration message sent by the base station; or The time information is derived from time information of the downlink radio resources allocated for transmission of downlink traffic in the first downlink flow.

15. The wireless communication method according to claim 13, characterized in that: The UE transmits an initial preferred start time to the base station and receives a start time determined by the base station as the preferred start time for the downlink traffic in the first downlink flow.

16. The wireless communication method according to claim 15, characterized in that: The start time determined by the base station is carried by the activation information of the CG or by the configuration message of the radio resource control RRC of the CG.

17. A wireless communication device, comprising: A processor, configured to call and run a computer program stored in a memory so that a device equipped with the processor executes the wireless communication method according to any one of claims 1 to 16.

18. A chip, comprising: A processor configured to call and run a computer program stored in a memory so that a device equipped with the chip executes the wireless communication method according to any one of claims 1 to 16.

19. A computer-readable storage medium storing a computer program, wherein the computer program enables a computer to execute the wireless communication method according to any one of claims 1 to 16.

20. A computer program product comprising a computer program, wherein the computer program enables a computer to execute the wireless communication method according to any one of claims 1 to 16.

21. A computer program, wherein the computer program enables a computer to execute the wireless communication method according to any one of claims 1 to 16.

22. A wireless communication method, which may be performed in a base station, comprising: Configuring a first enhanced configuration authorization CG for a first uplink flow, wherein the first uplink flow belongs to a first type of data flow; receiving an uplink transmission comprising uplink data and / or a status report for a first uplink flow on a CG granted by a first enhanced configuration; transmitting, within a predefined offset of a first duration after the CG belonging to the first enhanced configuration grant, an uplink dynamic grant for the first uplink flow in a physical downlink control channel PDCCH based on a status report of the first uplink flow received on the CG belonging to the first enhanced configuration grant; transmitting, within a predefined offset of a first duration after the CG belonging to the first enhanced configuration grant, a downlink dynamic allocation of the first downlink flow in the PDCCH if there is downlink traffic data for the first downlink flow to be transmitted; receiving, in accordance with the uplink dynamic grant for the first uplink flow, traffic data for the first uplink flow; and Traffic data of the first downlink flow is transmitted according to the downlink dynamic allocation of the first downlink flow.

23. The wireless communication method according to claim 22, characterized in that: The first downlink flow is configured to use the first enhanced configuration grant, wherein the first downlink flow may be synchronized with a period of the first uplink flow.

24. The wireless communication method according to claim 22, characterized in that: The status report in the uplink transmission comprises a buffer status report BSR.

25. The wireless communication method according to claim 22, characterized in that: The first duration is counted by a first timer of the first enhanced configuration authorization.

26. The wireless communication method according to claim 25, characterized in that: The first timer and / or the predefined offset are configured in the ConfiguredGrantConfig information element or in the downlink control information DCI or are predefined.

27. The wireless communication method according to claim 22, characterized in that: The first duration is an active time of a portion of the discontinuous reception (DRX) of the UE.

28. The wireless communication method according to claim 22, characterized in that: Also includes: configuring a second enhanced configuration authorization CG for a second uplink flow, wherein the second uplink flow belongs to a data flow of a second type; receiving an uplink transmission comprising uplink data and / or a status report for a second uplink flow on a CG granted by a second enhanced configuration; transmitting, within a predefined offset of a second duration after the CG belonging to the second enhanced configuration grant, an uplink dynamic grant for the second uplink flow in a physical downlink control channel PDCCH based on a status report of the second uplink flow received on the CG belonging to the second enhanced configuration grant; transmitting, within a predefined offset of a second duration after the CG belonging to the first enhanced configuration grant, a downlink dynamic allocation of the second downlink flow in the PDCCH if there is downlink traffic data for the second downlink flow to be transmitted; receiving traffic data for the second uplink flow in accordance with the uplink dynamic grant for the second uplink flow; and Traffic data of the second downlink flow is transmitted according to the downlink dynamic allocation of the second downlink flow.

29. The wireless communication method according to claim 28, characterized in that: The second downlink flow is configured to use the second enhanced configuration grant, wherein the second downlink flow may be synchronized with a period of the second uplink flow.

30. The wireless communication method according to claim 28, characterized in that: The second duration is counted by a second timer of the second enhanced configuration authorization.

31. The wireless communication method according to claim 28, characterized in that: The second duration is an active time of a portion of the discontinuous reception (DRX) of the UE.

32. The wireless communication method according to claim 22, characterized in that: Also includes: configuring a normal configuration grant for a third uplink flow, wherein the third uplink flow belongs to a data flow of a third type; as well as An uplink transmission is received for the third uplink flow in accordance with the normal configuration grant.

33. The wireless communication method according to claim 22, characterized in that: Also includes: Configuring a semi-persistent scheduling SPS for a second downlink flow, wherein the second downlink flow belongs to a data flow of a second type; as well as The traffic data belonging to the second downlink flow on the semi-persistent scheduling SPS is transmitted.

34. The wireless communication method according to claim 22, characterized in that: Also includes: Transmitting time information for transmitting the downlink service in the first downlink flow to the server through the mobility management function AMF, wherein the time information includes one or more of the following information: an estimated transmission delay time from the server to a base station serving the UE; time information of downlink radio resources allocated for transmitting said downlink traffic in said first downlink flow; and A preferred start time for downlink traffic in the first downlink flow at the server.

35. The wireless communication method according to claim 34, characterized in that: The base station determines the start time according to an initial preferred start time transmitted from the UE, and the start time determined by the base station serves as the preferred start time for the downlink traffic.

36. The wireless communication method according to claim 35, characterized in that: The start time determined by the base station is carried by the activation information in the CG or by the configuration message of the radio resource control RRC of the CG.

37. A wireless communication device, comprising: A processor, used to call and run a computer program stored in a memory so that a device equipped with the processor executes the wireless communication method described in any one of claims 22 to 36.

38. A chip, comprising: A processor configured to call and run a computer program stored in a memory so that a device equipped with the chip executes the wireless communication method described in any one of claims 22 to 36.

39. A computer-readable storage medium storing a computer program, wherein the computer program enables a computer to execute the wireless communication method according to any one of claims 22 to 36.

40. A computer program product, comprising a computer program, wherein the computer program enables a computer to execute the wireless communication method according to any one of claims 22 to 36.

41. A computer program, wherein the computer program enables a computer to execute the wireless communication method according to any one of claims 22 to 36.

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