WO2024119900A1

WO2024119900A1 - Delay report

Info

Publication number: WO2024119900A1
Application number: PCT/CN2023/114800
Authority: WO
Inventors: Xiaoying Xu; Mingzeng Dai; Jing HAN; Congchi ZHANG
Original assignee: Lenovo (Beijing) Limited
Priority date: 2023-08-24
Filing date: 2023-08-24
Publication date: 2024-06-13

Abstract

Various aspects of the present disclosure relate to delay report. In one aspect, a UE determines remaining time of a first timer for a first packet in a synchronization transmission set based on a value of the first timer and time of an initial transmission of a delay report. The synchronization transmission set comprising packets associated with multiple Quality of Service (QoS) flows. In turn, the UE transmits, to a base station, the delay report comprising information about the remaining time.

Description

DELAY REPORT

TECHNICAL FIELD

The present disclosure relates to wireless communications, and more specifically to user equipment (UE) , base station and methods for supporting delay report.

BACKGROUND

A wireless communications system may include one or multiple network communication devices, such as base stations, which may be otherwise known as an eNodeB (eNB) , a next-generation NodeB (gNB) , or other suitable terminology. Each network communication devices, such as a base station may support wireless communications for one or multiple user communication devices, which may be otherwise known as UE, or other suitable terminology. The wireless communications system may support wireless communications with one or multiple user communication devices by utilizing resources of the wireless communication system (e.g., time resources (e.g., symbols, slots, subframes, frames, or the like) or frequency resources (e.g., subcarriers, carriers) . Additionally, the wireless communications system may support wireless communications across various radio access technologies including third generation (3G) radio access technology, fourth generation (4G) radio access technology, fifth generation (5G) radio access technology, among other suitable radio access technologies beyond 5G (e.g., sixth generation (6G) ) .

The tactile and multi-modal communication service can be applied in multiple fields, such as industry, robotics and telepresence, virtual reality, augmented reality, healthcare, road traffic, serious gaming, education, culture and smart grid. These services support applications enabling input from more than one sources and/or output to more than one destinations to convey information more effectively. The input and output can be different modalities which may include at least one of the following: video/audio media; information received by sensors about the environment, such as brightness, temperature, humidity and so on; or haptic (or tactile) data which can be feelings when touching a surface (such as pressure, texture, vibration, temperature) , or kinaesthetic senses (such as gravity, pull forces, sense of position awareness) .

For immersive multi-modal virtual reality (VR) applications, synchronization between different media components is critical in order to avoid having a negative impact on the user experience (i.e., viewers detecting lack of synchronization) , particularly when the synchronization threshold between two or more modalities is less than the latency key performance indicator (KPI) for the application.

SUMMARY

The present disclosure relates to UEs, base station and methods that support delay report. With the UEs, base station and methods, delay report for synchronization flows may be achieved. Thus, good user experience may be obtained.

Some implementations of a UE described herein may include a processor and a transceiver coupled to the processor, wherein the processor is configured to: determine remaining time of a first timer for a first packet in a synchronization transmission set based on a value of the first timer and the time of an initial transmission of a delay report; and transmit, via the transceiver to a base station, the delay report comprising information about the remaining time.

In some implementations, the first timer comprises a discard timer or a synchronization timer.

In some implementations, the processor is further configured to: determine the value of the first timer based on arrival time or arrival orders of the first packet and a second packet in the synchronization transmission set.

In some implementations, the processor is configured to determine the value of the first timer by: receiving, via the transceiver from the base station, a configuration of multiple values of the first timer; and determining, based on the arrival time or the arrival orders, one of the multiple values as the value of the first timer.

In some implementations, the processor is configured to determine the value of the first timer by: receiving, via the transceiver from the base station, a configuration of a first value of the first timer associated with a data radio bearer (DRB) ; and determining the value of the first timer based on the first value of the first timer and the arrival time or the arrival orders.

In some implementations, the processor is configured to determine the value of the first timer by receiving, via the transceiver from the base station, a first configuration of a first value of the first timer; and the processor is further configured to: receive, via the transceiver from the base station, a second configuration of a second value of a second discard timer for the first packet associated with a data radio bearer (DRB) ; start the second discard timer for the first packet based on the second configuration; and based on determining that first arrival time of the first packet is later than second arrival time of the second packet by a second number of time units, start the first timer for the first packet based on the first configuration.

In some implementations, the first value is equal to or less than the second value.

In some implementations, the processor is further configured to: determine the synchronization transmission set; and discard the packets in the synchronization transmission set based on the synchronization transmission set.

In some implementations, the processor is configured to discard the packets in the synchronization transmission set by: based on determining that the first timer expires, discard all the packets in the synchronization transmission set.

In some implementations, the processor is configured to discard the packets in the synchronization transmission set by: receiving a first indication via the transceiver from the base station, the first indication indicating that the UE discards all the packets in the synchronization transmission set when one of the packets in the synchronization transmission set is discarded; and discarding the packets in the synchronization transmission set based on the first indication.

In some implementations, the processor is further configured to: receive a second indication via the transceiver from the base station, the second indication indicating that the UE performs a synchronization transmission for uplink.

In some implementations, the processor is further configured to: discard the packets in the synchronization transmission set based on the second indication.

In some implementations, the synchronization transmission set comprises a first packet associated with a first data radio bearer (DRB) and the second packet associated with a second DRB.

In some implementations, the processor is configured to discard the packets in the synchronization transmission set by: receiving a third indication for the first DRB via the transceiver from the base station, the third indication indicating that the UE considers a second discard timer associated with the second DRB expires if a first timer associated with the first DRB expires.

In some implementations, the processor is configured to discard the packets in the synchronization transmission set by: based on determining that the first discard time expires, providing a fourth indication from a first packet data convergence protocol (PDCP) entity of the UE to a second PDCP entity of the UE, the fourth indication indicating that the packets in the synchronization transmission set are to be discarded, the first PDCP entity being associated with the first DRB, and the second PDCP entity being associated with the second DRB.

In some implementations, the processor is configured to discard the packets in the synchronization transmission set by: receiving a fifth indication for the first DRB and the second DRB via the transceiver from the base station, the fifth indication indicating that the UE considers a second discard timer associated with the second DRB expires if a first timer associated with the first DRB expires, or the UE considers the first timer expires if the second discard timer expires.

In some implementations, the processor is configured to discard the packets in the synchronization transmission set by: based on determining that the first discard time expires, providing a sixth indication from a first packet data convergence protocol (PDCP) entity of the UE to a second PDCP entity of the UE, the sixth indication indicating that the packets in the synchronization transmission set are to be discarded, the first PDCP entity being associated with the first DRB, and the second PDCP entity being associated with the second DRB; and based on determining that the second discard time expires, providing the sixth indication from the second PDCP entity to the first PDCP entity.

In some implementations, the processor is configured to determine the synchronization transmission set by: determine the packets in the synchronization transmission set based on a gap between arrival time of the packets.

In some implementations, the processor is further configured to: determine arrival time or arrival orders of a first packet and a second packet in the synchronization transmission set; and transmit, via the transceiver to the base station, information about the arrival time, delay information or the arrival orders.

In some implementations, the first packet is associated with a first QoS flow or a first data radio bearer (DRB) , and the second packet is associated with a second QoS flow or a second DRB.

In some implementations, the processor is configured to start the first timer for the first packet by: based on determining that the first arrival time of the first packet is later than the second arrival time of the second packet by a second number of time units, starting the first timer for the first packet.

In some implementations, the processor is further configured to: start the first timer for the first packet based on the second indication.

Some implementations of a UE described herein may include a processor and a transceiver coupled to the processor, wherein the processor is configured to: determine a synchronization transmission set; and discard the packets in the synchronization transmission set based on the synchronization transmission set.

In some implementations, the processor is configured to discard the packets in the synchronization transmission set by: based on determining that a first timer for one of the packets in the synchronization transmission set expires, discard all the packets in the synchronization transmission set.

In some implementations, the processor is configured to discard the packets in the synchronization transmission set by: receiving a first indication via the transceiver from a base station, the first indication indicating that the UE discards all the packets in the synchronization transmission set when one of the packets in the synchronization transmission set is discarded; and discarding the packets in the synchronization transmission set based on the first indication.

In some implementations, the processor is configured to discard the packets in the synchronization transmission set by: receiving a second indication via the transceiver from a base station, the second indication indicating that the UE performs a synchronization transmission for uplink; and discarding the packets in the synchronization transmission set based on the second indication.

Some implementations of a base station described herein may include a processor and a transceiver coupled to the processor, wherein the processor is configured to: receive a delay report from a UE, the delay report comprising information about remaining time of a first discard timer for a first packet in a synchronization transmission set; and schedule the UE based on the delay report.

In some implementations, the processor is further configured to: transmit, via the transceiver to the UE, a configuration of multiple values of the first timer.

In some implementations, the processor is further configured to: transmit, via the transceiver to the UE, a configuration of a value of the first timer.

In some implementations, the processor is further configured to: transmit a first indication via the transceiver to the UE, the first indication indicating that the UE discards all the packets in the synchronization transmission set when one of the packets in the synchronization transmission set is discarded.

In some implementations, the processor is further configured to: transmit a second indication via the transceiver to the UE, the second indication indicating that the UE performs a synchronization transmission for uplink.

In some implementations, the synchronization transmission set comprises a first packet associated with a first DRB and the second packet associated with a second DRB.

In some implementations, the processor is further configured to: transmit a third indication for the first DRB via the transceiver to the UE, the third indication indicating that the UE considers a second discard timer associated with the second DRB expires if a first timer associated with the first DRB expires.

In some implementations, the processor is further configured to: transmit a fifth indication for the first DRB and the second DRB via the transceiver to the UE, the fifth indication indicating that the UE considers a second discard timer associated with the second DRB expires if a first timer associated with the first DRB expires, or the UE considers the first timer expires if the second discard timer expires.

In some implementations, the processor is further configured to: receive, via the transceiver from the UE or an apparatus in a core network, information about arrival time or arrival orders of the first packet and a second packet in the synchronization transmission set.

Some implementations of a method described herein may include: determining, at a UE, remaining time of a first discard timer for a first packet in a synchronization transmission set based on a value of the first discard timer and time of an initial transmission of a delay report, the synchronization transmission set comprising packets associated with one or multiple QoS flows; and transmitting, to a base station, the delay report comprising information about the remaining time.

Some implementations of a method described herein may include: determining, at a UE, a synchronization transmission set; and discarding the packets in the synchronization transmission set based on the synchronization transmission set.

Some implementations of a method described herein may include: receiving a delay report at a base station from a UE, the delay report comprising information about remaining time of a first discard timer for a first packet in a synchronization transmission set, ; and scheduling the UE based on the delay report.

Some implementations of a processor described herein may include at least one memory and a controller coupled with the at least one memory and configured to cause the controller to: determine remaining time of a first discard timer for a first packet in a synchronization transmission set based on a value of the first discard timer and time of an initial transmission of a delay report; and transmit, to a base station, the delay report comprising information about the remaining time.

Some implementations of a processor described herein may include at least one memory and a controller coupled with the at least one memory and configured to cause the controller to: determine a synchronization transmission set ; and discard the packets in the synchronization transmission set based on the synchronization transmission set.

It is to be understood that the summary section is not intended to identify key or essential features of embodiments of the present disclosure, nor is it intended to be used to limit the scope of the present disclosure. Other features of the present disclosure will become easily comprehensible through the following description.

BRIEF DESCRIPTION OF THE DRAWINGS

Fig. 1 illustrates an example of a wireless communications system that supports delay report in accordance with aspects of the present disclosure;

Fig. 2 illustrates a signaling diagram illustrating an example process that supports delay report in accordance with aspects of the present disclosure;

Fig. 3 illustrates an example of a synchronization transmission set in accordance with some implementations of the present disclosure;

Fig. 4 illustrates a flowchart of a method that supports delay report in accordance with aspects of the present disclosure;

Fig. 5 illustrates an example of a synchronization transmission set in accordance with some implementations of the present disclosure;

Figs. 6 and 7 illustrate a flowchart of a method that supports delay report in accordance with aspects of the present disclosure, respectively;

Figs. 8, 9 and 10 illustrate a flowchart of a method that supports discarding based on a synchronization transmission set in accordance with aspects of the present disclosure, respectively;

Fig. 11 illustrates an example of a device that supports delay report and discarding based on a synchronization transmission set in accordance with some aspects of the present disclosure; and

Fig. 12 illustrates an example of a processor that supports delay report discarding based on a synchronization transmission set in accordance with aspects of the present disclosure; and

Figs. 13 and 14 illustrate a flowchart of a method that supports delay report in accordance with aspects of the present disclosure, respectively.

DETAILED DESCRIPTION

Principles of the present disclosure will now be described with reference to some embodiments. It is to be understood that these embodiments are described only for the purpose of illustration and help those skilled in the art to understand and implement the present disclosure, without suggesting any limitation as to the scope of the disclosure. The disclosure described herein may be implemented in various manners other than the ones described below.

In the following description and claims, unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skills in the art to which this disclosure belongs.

References in the present disclosure to “one embodiment, ” “an example embodiment, ” “an embodiment, ” “some embodiments, ” and the like indicate that the embodiment (s) described may include a particular feature, structure, or characteristic, but it is not necessary that every embodiment includes the particular feature, structure, or characteristic. Moreover, such phrases do not necessarily refer to the same embodiment (s) . Further, when a particular feature, structure, or characteristic is described in connection with an embodiment, it is submitted that it is within the knowledge of one skilled in the art to affect such feature, structure, or characteristic in connection with other embodiments whether or not explicitly described.

It shall be understood that although the terms “first” and “second” or the like may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another element. For example, a first element could also be termed as a second element, and similarly, a second element could also be termed as a first element, without departing from the scope of embodiments. As used herein, the term “and/or” includes any and all combinations of one or more of the listed terms.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments. As used herein, the singular forms “a” , “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises” , “comprising” , “has” , “having” , “includes” and/or “including” , when used herein, specify the presence of stated features, elements, and/or components etc., but do not preclude the presence or addition of one or more other features, elements, components and/or combinations thereof.

As described above, for immersive multi-modal VR applications, synchronization between different media components is critical in order to avoid having a negative impact on the user experience (i.e., viewers detecting lack of synchronization) , particularly when the synchronization threshold between two or more modalities is less than the latency key performance indicator (KPI) for the application. Table 1 provides an example of typical synchronization thresholds for immersive multi-modality VR applications.

Table 1

It shall be noted that in Table 1, for each media component, “delay” refers to the case where that media component is delayed compared to the other. For example, the “visual delay” of 15 ms refers to the case where visual media is delayed by 15 ms compared to tactile data.

Since each modality may have different Quality of Service (QoS) requirement, it is possible that different modalities are carried by different QoS flows. As described above, synchronization between modalities is critical. However, currently, radio access network (RAN) has no synchronization information regarding QoS flows for different modalities. Lacking the synchronization information for multi-modal communication services, the transmission performances of different flows in RAN are independent. We cannot guarantee the transmission performances (such as packet error ratio (PER) ) of correlated flows in a same level within certain durations. Thus, the user experience for the multi-modal communication services cannot be guaranteed. Therefore, RAN should be aware of synchronization information of different QoS flows for multi-modal communication service.

In Release 18, protocol data unit (PDU) set based transmission based on delay status of buffered data is enabled for Extended Reality (XR) service. That is, a UE reports the delay status of buffered data (i.e., remaining discard timer value, the reference time is the initial transmission of the report) to a network for the delay awareness scheduling for a PDU set. For immersive multi-modal VR applications, synchronization transmission between different media components is critical to avoid having a negative impact on the user experience. How to support synchronization transmission for dependent PDU (s) and/or PDU set (s) among the QoS flows of the multi-modal service with synchronization threshold needs to be solved. For example, how to determine and report the delay status for the PDU set (s) of the synchronization QoS flows with synchronization threshold should be designed. In addition, how to support synchronization discarding needs to be considered.

In view of the above, the present disclosure provides a solution that supports delay report. In this solution, a UE determines remaining time of a first discard timer for a first packet in a synchronization transmission set based on a value of the first discard timer and time of an initial transmission of a delay report. The synchronization transmission set comprising packets associated with multiple Quality of Service (QoS) flows. In turn, the UE transmits, to a base station, the delay report comprising information about the remaining time. In this way, delay report for synchronization flows may be achieved. Thus, good user experience may be obtained.

Aspects of the present disclosure are described in the context of a wireless communications system.

Fig. 1 illustrates an example of a wireless communications system 100 that supports delay report in accordance with aspects of the present disclosure. The wireless communications system 100 may include one at least one of network entities 102 (also referred to as network equipment (NE) ) , one or more terminal devices or UEs 104, a core network 106, and a packet data network 108. The wireless communications system 100 may support various radio access technologies. In some implementations, the wireless communications system 100 may be a 4G network, such as an LTE network or an LTE-advanced (LTE-A) network. In some other implementations, the wireless communications system 100 may be a 5G network, such as an NR network. In other implementations, the wireless communications system 100 may be a combination of a 4G network and a 5G network, or other suitable radio access technology including institute of electrical and electronics engineers (IEEE) 802.11 (Wi-Fi) , IEEE 802.16 (WiMAX) , IEEE 802.20. The wireless communications system 100 may support radio access technologies beyond 5G. Additionally, the wireless communications system 100 may support technologies, such as time division multiple access (TDMA) , frequency division multiple access (FDMA) , or code division multiple access (CDMA) , etc.

The network entities 102 may be collectively referred to as network entities 102 or individually referred to as a network entity 102.

The network entities 102 may be dispersed throughout a geographic region to form the wireless communications system 100. One or more of the network entities 102 described herein may be or include or may be referred to as a network node, a base station (BS) , a network element, a radio access network (RAN) node, a base transceiver station, an access point, a NodeB, an eNodeB (eNB) , a next-generation NodeB (gNB) , or other suitable terminology. A network entity 102 and a UE 104 may communicate via a communication link 110, which may be a wireless or wired connection. For example, a network entity 102 and a UE 104 may perform wireless communication (e.g., receive signaling, transmit signaling) over a Uu interface.

A network entity 102 may provide a geographic coverage area 112 for which the network entity 102 may support services (e.g., voice, video, packet data, messaging, broadcast, etc. ) for one or more UEs 104 within the geographic coverage area 112. For example, a network entity 102 and a UE 104 may support wireless communication of signals related to services (e.g., voice, video, packet data, messaging, broadcast, etc. ) according to one or multiple radio access technologies. In some implementations, a network entity 102 may be moveable, for example, a satellite associated with a non-terrestrial network. In some implementations, different geographic coverage areas 112 associated with the same or different radio access technologies may overlap, but the different geographic coverage areas 112 may be associated with different network entities 102. Information and signals described herein may be represented using any of a variety of different technologies and techniques. For example, data, instructions, commands, information, signals, bits, symbols, and chips that may be referenced throughout the description may be represented by voltages, currents, electromagnetic waves, magnetic fields or particles, optical fields or particles, or any combination thereof.

The one or more UEs 104 may be dispersed throughout a geographic region of the wireless communications system 100. A UE 104 may include or may be referred to as a mobile device, a wireless device, a remote device, a remote unit, a handheld device, or a subscriber device, or some other suitable terminology. In some implementations, the UE 104 may be referred to as a unit, a station, a terminal, or a client, among other examples. Additionally, or alternatively, the UE 104 may be referred to as an internet-of-things (IoT) device, an internet-of-everything (IoE) device, or machine-type communication (MTC) device, among other examples. In some implementations, a UE 104 may be stationary in the wireless communications system 100. In some other implementations, a UE 104 may be mobile in the wireless communications system 100.

The one or more UEs 104 may be devices in different forms or having different capabilities. Some examples of UEs 104 are illustrated in Fig. 1. A UE 104 may be capable of communicating with various types of devices, such as the network entities 102, other UEs 104, or network equipment (e.g., the core network 106, the packet data network 108, a relay device, an integrated access and backhaul (IAB) node, or another network equipment) , as shown in Fig. 1. Additionally, or alternatively, a UE 104 may support communication with other network entities 102 or UEs 104, which may act as relays in the wireless communications system 100.

A UE 104 may also be able to support wireless communication directly with other UEs 104 over a communication link 114. For example, a UE 104 may support wireless communication directly with another UE 104 over a device-to-device (D2D) communication link. In some implementations, such as vehicle-to-vehicle (V2V) deployments, vehicle-to-everything (V2X) deployments, or cellular-V2X deployments, the communication link 114 may be referred to as a sidelink. For example, a UE 104 may support wireless communication directly with another UE 104 over a PC5 interface.

A network entity 102 may support communications with the core network 106, or with another network entity 102, or both. For example, a network entity 102 may interface with the core network 106 through one or more backhaul links 116 (e.g., via an S1, N2, N2, or another network interface) . The network entities 102 may communicate with each other over the backhaul links 116 (e.g., via an X2, Xn, or another network interface) . In some implementations, the network entities 102 may communicate with each other directly (e.g., between the network entities 102) . In some other implementations, the network entities 102 may communicate with each other or indirectly (e.g., via the core network 106) . In some implementations, one or more network entities 102 may include subcomponents, such as an access network entity, which may be an example of an access node controller (ANC) . An ANC may communicate with the one or more UEs 104 through one or more other access network transmission entities, which may be referred to as a radio heads, smart radio heads, or transmission-reception points (TRPs) .

In some implementations, a network entity 102 may be configured in a disaggregated architecture, which may be configured to utilize a protocol stack physically or logically distributed among two or more network entities 102, such as an integrated access backhaul (IAB) network, an open radio access network (O-RAN) (e.g., a network configuration sponsored by the O-RAN Alliance) , or a virtualized RAN (vRAN) (e.g., a cloud RAN (C-RAN) ) . For example, a network entity 102 may include one or more of a central unit (CU) , a distributed unit (DU) , a radio unit (RU) , a RAN intelligent controller (RIC) (e.g., a near-real time RIC (Near-RT RIC) , a non-real time RIC (Non-RT RIC) ) , a service management and orchestration (SMO) system, or any combination thereof.

An RU may also be referred to as a radio head, a smart radio head, a remote radio head (RRH) , a remote radio unit (RRU) , or a transmission reception point (TRP) . One or more components of the network entities 102 in a disaggregated RAN architecture may be co-located, or one or more components of the network entities 102 may be located in distributed locations (e.g., separate physical locations) . In some implementations, one or more network entities 102 of a disaggregated RAN architecture may be implemented as virtual units (e.g., a virtual CU (VCU) , a virtual DU (VDU) , a virtual RU (VRU) ) .

Split of functionality between a CU, a DU, and an RU may be flexible and may support different functionalities depending upon which functions (e.g., network layer functions, protocol layer functions, baseband functions, radio frequency functions, and any combinations thereof) are performed at a CU, a DU, or an RU. For example, a functional split of a protocol stack may be employed between a CU and a DU such that the CU may support one or more layers of the protocol stack and the DU may support one or more different layers of the protocol stack. In some implementations, the CU may host upper protocol layer (e.g., a layer 3 (L3) , a layer 2 (L2) ) functionality and signaling (e.g., radio resource control (RRC) , service data adaption protocol (SDAP) , packet data convergence protocol (PDCP) ) . The CU may be connected to one or more DUs or RUs, and the one or more DUs or RUs may host lower protocol layers, such as a layer 1 (L1) (e.g., physical (PHY) layer) or an L2 (e.g., radio link control (RLC) layer, medium access control (MAC) layer) functionality and signaling, and may each be at least partially controlled by the CU 160.

Additionally, or alternatively, a functional split of the protocol stack may be employed between a DU and an RU such that the DU may support one or more layers of the protocol stack and the RU may support one or more different layers of the protocol stack. The DU may support one or multiple different cells (e.g., via one or more RUs) . In some implementations, a functional split between a CU and a DU, or between a DU and an RU may be within a protocol layer (e.g., some functions for a protocol layer may be performed by one of a CU, a DU, or an RU, while other functions of the protocol layer are performed by a different one of the CU, the DU, or the RU) .

A CU may be functionally split further into CU control plane (CU-CP) and CU user plane (CU-UP) functions. A CU may be connected to one or more DUs via a midhaul communication link (e.g., F1, F1-c, F1-u) , and a DU may be connected to one or more RUs via a fronthaul communication link (e.g., open fronthaul (FH) interface) . In some implementations, a midhaul communication link or a fronthaul communication link may be implemented in accordance with an interface (e.g., a channel) between layers of a protocol stack supported by respective network entities 102 that are in communication via such communication links.

The core network 106 may support user authentication, access authorization, tracking, connectivity, and other access, routing, or mobility functions. The core network 106 may be an evolved packet core (EPC) , or a 5G core (5GC) , which may include a control plane entity that manages access and mobility (e.g., a mobility management entity (MME) , an access and mobility management functions (AMF) ) and a user plane entity that routes packets or interconnects to external networks (e.g., a serving gateway (S-GW) , a packet data network (PDN) gateway (P-GW) , or a user plane function (UPF) ) . In some implementations, the control plane entity may manage non-access stratum (NAS) functions, such as mobility, authentication, and bearer management (e.g., data bearers, signal bearers, etc. ) for the one or more UEs 104 served by the one or more network entities 102 associated with the core network 106.

The core network 106 may communicate with the packet data network 108 over one or more backhaul links 116 (e.g., via an S1, N2, N2, or another network interface) . The packet data network 108 may include an application server 118. In some implementations, one or more UEs 104 may communicate with the application server 118. A UE 104 may establish a session (e.g., a protocol data unit (PDU) session, or the like) with the core network 106 via a network entity 102. The core network 106 may route traffic (e.g., control information, data, and the like) between the UE 104 and the application server 118 using the established session (e.g., the established PDU session) . The PDU session may be an example of a logical connection between the UE 104 and the core network 106 (e.g., one or more network functions of the core network 106) .

In the wireless communications system 100, the network entities 102 and the UEs 104 may use resources of the wireless communications system 100 (e.g., time resources (e.g., symbols, slots, subframes, frames, or the like) or frequency resources (e.g., subcarriers, carriers) ) to perform various operations (e.g., wireless communications) . In some implementations, the network entities 102 and the UEs 104 may support different resource structures. For example, the network entities 102 and the UEs 104 may support different frame structures. In some implementations, such as in 4G, the network entities 102 and the UEs 104 may support a single frame structure. In some other implementations, such as in 5G and among other suitable radio access technologies, the network entities 102 and the UEs 104 may support various frame structures (i.e., multiple frame structures) . The network entities 102 and the UEs 104 may support various frame structures based on one or more numerologies.

One or more numerologies may be supported in the wireless communications system 100, and a numerology may include a subcarrier spacing and a cyclic prefix. A first numerology (e.g., μ=0) may be associated with a first subcarrier spacing (e.g., 15 kHz) and a normal cyclic prefix. In some implementations, the first numerology (e.g., μ=0) associated with the first subcarrier spacing (e.g., 15 kHz) may utilize one slot per subframe. A second numerology (e.g., μ=1) may be associated with a second subcarrier spacing (e.g., 30 kHz) and a normal cyclic prefix. A third numerology (e.g., μ=2) may be associated with a third subcarrier spacing (e.g., 60 kHz) and a normal cyclic prefix or an extended cyclic prefix. A fourth numerology (e.g., μ=3) may be associated with a fourth subcarrier spacing (e.g., 120 kHz) and a normal cyclic prefix. A fifth numerology (e.g., μ=4) may be associated with a fifth subcarrier spacing (e.g., 240 kHz) and a normal cyclic prefix.

A time interval of a resource (e.g., a communication resource) may be organized according to frames (also referred to as radio frames) . Each frame may have a duration, for example, a 10 millisecond (ms) duration. In some implementations, each frame may include multiple subframes. For example, each frame may include 10 subframes, and each subframe may have a duration, for example, a 1 ms duration. In some implementations, each frame may have the same duration. In some implementations, each subframe of a frame may have the same duration.

Additionally or alternatively, a time interval of a resource (e.g., a communication resource) may be organized according to slots. For example, a subframe may include a number (e.g., quantity) of slots. The number of slots in each subframe may also depend on the one or more numerologies supported in the wireless communications system 100. For instance, the first, second, third, fourth, and fifth numerologies (i.e., μ=0, μ=1, μ=2, μ=3, μ=4) associated with respective subcarrier spacings of 15 kHz, 30 kHz, 60 kHz, 120 kHz, and 240 kHz may utilize a single slot per subframe, two slots per subframe, four slots per subframe, eight slots per subframe, and 16 slots per subframe, respectively. Each slot may include a number (e.g., quantity) of symbols (e.g., OFDM symbols) . In some implementations, the number (e.g., quantity) of slots for a subframe may depend on a numerology. For a normal cyclic prefix, a slot may include 14 symbols. For an extended cyclic prefix (e.g., applicable for 60 kHz subcarrier spacing) , a slot may include 12 symbols. The relationship between the number of symbols per slot, the number of slots per subframe, and the number of slots per frame for a normal cyclic prefix and an extended cyclic prefix may depend on a numerology. It should be understood that reference to a first numerology (e.g., μ=0) associated with a first subcarrier spacing (e.g., 15 kHz) may be used interchangeably between subframes and slots.

In the wireless communications system 100, an electromagnetic (EM) spectrum may be split, based on frequency or wavelength, into various classes, frequency bands, frequency channels, etc. By way of example, the wireless communications system 100 may support one or multiple operating frequency bands, such as frequency range designations FR1 (510 MHz –7.125 GHz) , FR2 (24.25 GHz –52.6 GHz) , FR3 (7.125 GHz –24.25 GHz) , FR4 (52.6 GHz –114.25 GHz) , FR4a or FR4-1 (52.6 GHz –71 GHz) , and FR5 (114.25 GHz –300 GHz) . In some implementations, the network entities 102 and the UEs 104 may perform wireless communications over one or more of the operating frequency bands. In some implementations, FR1 may be used by the network entities 102 and the UEs 104, among other equipment or devices for cellular communications traffic (e.g., control information, data) . In some implementations, FR2 may be used by the network entities 102 and the UEs 104, among other equipment or devices for short-range, high data rate capabilities.

FR1 may be associated with one or multiple numerologies (e.g., at least three numerologies) . For example, FR1 may be associated with a first numerology (e.g., μ=0) , which includes 15 kHz subcarrier spacing; a second numerology (e.g., μ=1) , which includes 30 kHz subcarrier spacing; and a third numerology (e.g., μ=2) , which includes 60 kHz subcarrier spacing. FR2 may be associated with one or multiple numerologies (e.g., at least 2 numerologies) . For example, FR2 may be associated with a third numerology (e.g., μ=2) , which includes 60 kHz subcarrier spacing; and a fourth numerology (e.g., μ=3) , which includes 120 kHz subcarrier spacing.

Fig. 2 illustrates a signaling diagram illustrating an example process 200 that supports delay report in accordance with aspects of the present disclosure. The process 200 may involve the UE 104 and the base station 102 in Fig. 1. For the purpose of discussion, the process 200 will be described with reference to Fig. 1.

As shown in Fig. 2, the UE 104 determines 210 remaining time of a first discard timer for a first packet in a synchronization transmission set based on a value of the first discard timer and time of an initial transmission of a delay report.

In some implementations, the synchronization transmission set comprises packets associated with one or multiple QoS flows.

In some implementations, a set of packets which are carried by one or multiple QoS flows and need synchronization transmission may be defined as a synchronization transmission set.

In some implementations, the synchronization transmission set may be referred to as synchronization protocol data unit (PDU) sets. For example, the synchronization transmission set may comprise at least two PDU sets and each of the at least two PDU sets is associated with a QoS flow.

In some implementations, the synchronization transmission set may comprise one or more PDUs associated with a first QoS flow as well as one or more PDUs associated with a second QoS flow. The first QoS flow and the second QoS flow are QoS flows that are indicated by synchronization transmission association of QoS flows.

Alternatively, in some implementations, the synchronization transmission set may comprise one or more PDU sets associated with the first QoS flow as well as one or more PDUs associated with the second QoS flow.

Alternatively, in some implementations, the synchronization transmission set may comprise one or more PDU sets associated with the first QoS flow as well as one or more PDU sets associated with the second QoS flow.

In some implementations, a PDU set may comprise one or more PDUs carrying the payload of one unit of information generated at an application level. For example, the unit of information may be a frame or video slice for XR services. In some implementations, all PDUs in a PDU set are needed by an application layer of the UE 104 to use the corresponding unit of information. In other implementations, the application layer can still recover parts or all of the information unit when some PDUs are missing.

In some implementations, the synchronization transmission set may comprise one or more data bursts associated with the first QoS flow as well as one or more data bursts associated with the second QoS flow. In some implementations, a data burst may be a set of multiple PDUs generated and sent by an application in a short period of time. Alternatively, in some implementations, a data burst may comprise one or multiple PDU sets.

In some implementations, the synchronization transmission set may be carried on one data radio bearer (DRB) . Alternatively, the synchronization transmission set may be carried on multiple DRBs. For example, the multiple DRBs may comprise a first DRB and a second DRB. Hereinafter, some implementations of the present disclosure will be described by taking two DRBs for example.

Fig. 3 illustrates an example of a synchronization transmission set in accordance with some implementations of the present disclosure. As shown in Fig. 3, a synchronization transmission set comprises one or more PDU sets associated with a first QoS flow as well as one or more PDUs associated with the second QoS flow. The first QoS flow may be a video flow and the second QoS flow may be a haptic flow. For example, a synchronization (SYNC) transmission set 300 comprises a PDU set 310 of the video flow as well as PDUs 320, 322 and 324 of the haptic flow. The PDU set 310 comprises three PDUs.

Return to Fig. 2, the UE 104 transmits 220, to the base station 102, the delay report comprising information about the remaining time.

In some implementations, the information about the remaining time may comprise at least one of the following: the remaining time, or amount of buffered data corresponding to the remaining time. The amount of buffered data corresponding to the remaining time is also referred to as a buffer size. The remaining time is less than or equal to a remaining time threshold. The remaining time threshold may be configured to the UE 104 by the base station 102.

In some implementations, the remaining time may be the shortest remaining time of the buffered data of a logical channel (LCH) or a logical channel group (LCG) .

In some implementations, the delay report for an LCG may include more than one information about the remaining time. For example, the delay report for an LCG includes two amounts of buffered data, each of which is corresponding to a different remaining time.

Upon receiving the delay report, the base station 102 schedules 230 the UE 104 based on the delay report.

In some implementations, to guarantee the transmission delay threshold for multi-modality VR applications, the UE 104 may determine the value of the first discard timer based on arrival time or arrival orders of the first packet and a second packet in the synchronization transmission set. This will be described with reference to Figs. 4 to 7.

Fig. 4 illustrates a flowchart of a method 400 that supports delay report in accordance with aspects of the present disclosure. The operations of the method 400 may be implemented by a device or its components as described herein. For example, the operations of the method 400 may be performed by the UE 104 as described herein. In some implementations, the device may execute a set of instructions to control the function elements of the device to perform the described functions. Additionally, or alternatively, the device may perform aspects of the described functions using special-purpose hardware.

At 410, the UE 104 may receive, from the base station 102, a configuration of multiple values of the first discard timer. For example, the configuration of multiple values of the first discard timer may be a configuration of multiple values of the first discard timer associated with a DRB.

At 420, the UE 104 may determine, based on the arrival time or the arrival orders, one of the multiple values as the value of the first discard timer.

In some implementations, the UE 104 may determine whether first arrival time of the first packet is later than second arrival time of the second packet. If the first arrival time of the first packet is earlier than or the same as the second arrival time of the second packet, the UE 104 may determine a first value among the multiple values as the value of the first discard timer. If the first arrival time of the first packet is later than the second arrival time of the second packet, the UE 104 may determine a second value among the multiple values as the value of the first discard timer. The second value may be equal to or less than the first value.

In some implementations, the UE 104 may determine whether first arrival time of the first packet is later than second arrival time of the second packet. If the first arrival time of the first packet is earlier than the second arrival time of the second packet, the UE 104 may further determine whether the first arrival time of the first packet is earlier than the second arrival time of the second packet by a first number of time units. If the first arrival time of the first packet is earlier than second arrival time of the second packet by the first number of time units, the UE 104 may determine a first value among the multiple values as the value of the first discard timer. If the first arrival time of the first packet is later than the second arrival time of the second packet, the UE 104 may further determine whether first arrival time of the first packet is later than second arrival time of the second packet by a second number of time units. If the first arrival time of the first packet is later than the second arrival time of the second packet by the second number of time units, the UE 104 may determine a second value among the multiple values as the value of the first discard timer. The second value may be equal to or less than the first value.

In some implementations, at least one of the first number of time units or the second number of time units may be configured by the base station 102 or pre-defined.

Fig. 5 illustrates an example of a synchronization transmission set in accordance with some implementations of the present disclosure. As shown in Fig. 5, a synchronization transmission set comprises one or more PDU sets associated with a first QoS flow as well as one or more PDUs associated with a second QoS flow. The first QoS flow may be a video flow and the second QoS flow may be a haptic flow. For example, a synchronization (SYNC) transmission set 500 comprises a PDU set 510 of the video flow as well as PDUs 520 and 522 of the haptic flow. The PDU set 510 comprises PDUs 512, 514 and 516. The PDUs 512, 514 and 516 of the video flow are carried on a first DRB. That is, the PDUs 512, 514 and 516 of the video flow are associated with the first DRB. The PDUs 520 and 522 are carried on a second DRB. That is, the PDUs 520 and 522 are associated with the second DRB.

The UE 104 may receive, from the base station 102, a configuration of multiple values of a discard timer. For example, the configuration of multiple values of the discard timer may be a configuration of multiple values of a discard timer associated with a DRB or an LCH. The multiple values may comprise a first value and a second value. The second value may be equal to or less than the first value. In turn, the UE 104 may determine, based on the arrival time or the arrival orders, one of the first value and the second value as the value of the discard timer for the initial service data unit (SDU) corresponding to the initial PDU 512. The UE 104 starts a discard timer for the initial SDU. Further, the UE 104 starts a discard timer for each SDU corresponding to each PDU in the PDU set 510.

In some implementations, the UE 104 may determine whether arrival time of a first PDU in the PDU set 510 is later than arrival time of a second PDU among the PDUs 520 and 522. The second PDU may be the initial PDU or last PDU preceding of the first PDU. The first PDU may be the initial PDU or any PDU in the PDU set 510. If the arrival time of the first PDU is earlier than or the same as the arrival time of the second PDU, the UE 104 may set the first value as the value of the discard timer for the first SDU corresponding to the first PDU. If the arrival time of the first PDU is later than the arrival time of the second PDU, the UE 104 may set the second value as the value of the discard timer for the first SDU corresponding to the first PDU. For example, the UE 104 may determine whether arrival time of the initial PDU 512 in the PDU set 510 is later than arrival time of the initial PDU 520 among the PDUs 520 and 522. If the arrival time of the initial PDU 512 is earlier than or the same as the arrival time of the initial PDU 520, the UE 104 may set the first value as the value of the discard timer for the initial SDU corresponding to the initial PDU 512. If the arrival time of the initial PDU 512 is later than the arrival time of the initial PDU 520, the UE 104 may set the second value as the value of the discard timer for the initial SDU corresponding to the initial PDU 512.

For example, as shown in Fig. 5, the arrival time of the initial PDU 512 is later than the arrival time of the initial PDU 520 by Y time units, the UE 104 may set the second value as the value of the discard timer for the initial SDU corresponding to the initial PDU 512.

If the discard timer for the initial PDU 512 expires, the UE 104 may discard all PDCP SDUs associated with the PDU set 510 or associated with the synchronization transmission set 500. In this way, independent discarding per DRB may be achieved, which is simpler at the cost of the shorter value for a discard timer. Fig. 6 illustrates a flowchart of a method 600 that supports delay report in accordance with aspects of the present disclosure. The operations of the method 600 may be implemented by a device or its components as described herein. For example, the operations of the method 600 may be performed by the UE 104 as described herein. In some implementations, the device may execute a set of instructions to control the function elements of the device to perform the described functions. Additionally, or alternatively, the device may perform aspects of the described functions using special-purpose hardware.

At 610, the UE 104 may receive, from the base station 102, a configuration of a first value of the first discard timer associated with a DRB. In other words, the UE 104 may receive, from the base station 102, a configuration of a single value of the first discard timer associated with a DRB.

At 620, the UE 104 may determine the value of the first discard timer based on the first value and the arrival time or the arrival orders.

In some implementations, the first discard timer may be managed in a PDCP entity of the UE 104. Alternatively, the first discard timer may be managed at a medium access control (MAC) layer of the UE 104.

Still consider the example of Fig. 5. The UE 104 may receive, from the base station 102, a configuration of a first value (i.e., a single value) of a discard timer for an SDU corresponding to a PDU in the PDU set 510. For example, the configuration of the first value of the discard timer may be a configuration of the first value of a discard timer for the SDU corresponding to the PDU 512. In turn, the UE 104 may determine the value of the first discard timer for the SDU corresponding to the PDU 512 based on the first value and the arrival time or the arrival orders.

In some implementations, the UE 104 may determine whether arrival time of the initial PDU 512 in the PDU set 510 is later than arrival time of the initial PDU 520 among the PDUs 520 and 522. If the arrival time of the initial PDU 512 is earlier than or the same as the arrival time of the initial PDU 520, the UE 104 may set the first value as the value of the discard timer for the initial SDU corresponding to the initial PDU 512. If the arrival time of the initial PDU 512 is later than the arrival time of the initial PDU 520, the UE 104 may set a second value as the value of the discard timer for the initial SDU corresponding to the initial PDU 512. The second value may be equal to a difference between the first value and a second number, wherein the arrival time of the initial PDU 512 is later than the arrival time of the initial PDU 520 by the second number (represented by Y) of time units.

In some implementations, the first value may be a synchronization threshold that indicates the time or latency that the synchronization transmission should be satisfied. The transmission delay of two sets of PDUs should not be larger than the synchronization threshold.

For example, as shown in Fig. 5, the arrival time of the initial PDU 512 is later than the arrival time of the initial PDU 520 by Y time units, the UE 104 may set the second value as the value of the discard timer for the initial SDU corresponding to the initial PDU 512. The second value is equal to a difference between the first value and Y.

In some implementations, the second number of time units may be configured by the base station 102 or pre-defined.

In some implementations, the UE 104 may start two discard timers based on arrival order or arrival timing of packets in a synchronization transmission set . This will be described with reference to Fig. 7.

Fig. 7 illustrates a flowchart of a method 700 that supports delay report in accordance with aspects of the present disclosure. The operations of the method 700 may be implemented by a device or its components as described herein. For example, the operations of the method 700 may be performed by the UE 104 as described herein. In some implementations, the device may execute a set of instructions to control the function elements of the device to perform the described functions. Additionally, or alternatively, the device may perform aspects of the described functions using special-purpose hardware.

At 710, the UE 104 may receive, from the base station 102, a first configuration of a first value of the first discard timer for the first packet associated with a first DRB or a first QoS flow.

At 720, The UE 104 may receive, from the base station 102, a second configuration of a second value of a second discard timer for the first packet associated with the first DRB or the first QoS flow. In some implementations, the first value may be equal to or less than the second value.

At 730, the UE 104 may start the second discard timer for the first packet based on the second configuration by default. For example, the UE 104 may start the second discard timer for an SDU corresponding to the first packet.

At 740, if the UE 104 determines that first arrival time of the first packet associated with the first DRB or the first QoS flow is later than second arrival time of the second packet associated with a second DRB or a second QoS flow by a second number of time units, the UE 104 may start the first discard timer for the first packet based on the first configuration. For example, the UE 104 may start the first discard timer for an SDU corresponding to the second packet.

In some implementations, if the discard timer for any PDU in the PDU set or the initial PDU 512 expires, the UE 104 may discard the PDCP SDU, and the UE 104 may further discard all PDCP SDUs associated with the PDU set 510 or associated with the synchronization transmission set 500. For example, if the discard timer for any PDU in the PDU set or for the initial PDU 512 expires, the UE 104 may discard all PDCP SDUs associated with the PDU set 510 based on the PDU set discard indication or associated with the synchronization transmission set 500 based on the synchronization transmission set discard indication.

In some implementations, the first discard timer and the second discard timer may be used in the same case. For example, the first discard timer and the second discard timer are used in either UL non-congestion case or UL congestion case. For example, the first discard timer and the second discard timer are used for packets with one PDU set importance (PSI) in case of the PDU set importance based discard.

In some implementations, the UE 104 may determine arrival time or arrival orders of a first packet and a second packet in the synchronization transmission set. For example, the UE 104 may determine the arrival time or arrival orders of the packets in the synchronization transmission set associated with multiple QoS flows according to the statistics in a period.

In turn, the UE 104 may transmit information about the arrival time, delay information or the arrival orders to the base station 102. For example, the UE 104 may transmit information about which packets in the synchronization transmission set arrives earlier. For example, the UE 104 may transmit information about which QoS flow or DRB carrying the synchronization transmission set arrives earlier. Alternatively or additionally, the UE 104 may transmit the information about the arrival time, delay information or the arrival orders to an apparatus in the core network 106.

Then, based on the information about the arrival time, delay information or the arrival orders, the base station 102 may determine one value of a discard timer for a packet (for example, an initial packet) associated with a DRB in the synchronization transmission set. In turn, the base station 102 may transmit a configuration of the one value of the discard timer to the UE 104. Thus, selecting one of the multiple values of the discard timer may be avoided.

Upon receiving the configuration of the one value of the discard timer, the UE 104 may start the discard timer for the packet. For example, the UE 104 may start the discard timer for an SDU corresponding to the packet.

In some implementations, if the discard timer for the SDU expires, the UE 104 may discards all SDUs associated with a PDU set or associated with the synchronization transmission set.

In some implementations, the second discard timer for a PDU in the PDU set expires, the UE 104 does not discard the PDCP SDU and the corresponding PDU. That means the UE 104 discards the PDCP SDU only based on the expiration of the first discard timer, which is considered as a legacy discard timer.

In some implementations, an apparatus in the core network 106 may transmit, to the base station 102, information about arrival time or arrival orders of a first packet and a second packet in the synchronization transmission set.

For example, an application function (AF) or a mobility management function (AMF) in the core network 106 may transmit the information about arrival time or arrival orders to the base station 102.

Then, based on the information about the arrival time, delay information or the arrival orders, the base station 102 may determine at least one value of a discard timer for a packet (for example, an initial packet) associated with a DRB in the synchronization transmission set. In turn, the base station 102 may transmit a configuration of the at least one value of the discard timer to the UE 104.

In some implementations, to avoid the legacy discard effect by the first discard timer with lower value, the UE 104 may receive, from the base station 102, a configuration of a new timer . The new timer may be referred to as a synchronization timer. The new timer is separate from the discard timer in PDCP entity. The value of the new timer is configured based on the synchronization threshold by the base station 102. The base station 102 may receive the synchronization threshold from the core network 106 or from the UE 104. If the arrival time of the first PDU is later than the arrival time of the second PDU, the UE 104 starts the new timer for the first SDU in the PDU set 510. The second PDU may be the initial PDU 520 or last PDU 522 prior to the first PDU in the PDU set 510. The first PDU may be the initial PDU or every PDU in the PDU set 510. The timer may be maintained in PDCP entity or MAC entity.

In some implementations, for example, the configuration of multiple values of the new timer may be a configuration of multiple values of a timer. The multiple values may comprise a first value and a second value. The second value may be equal to or less than the first value. If the arrival time of the first PDU is later than or the same as the arrival time of the second PDU, the UE 104 may set the second value as the value of the timer for the first SDU corresponding to the first PDU. The second PDU may be the initial PDU 520 or last PDU 522prior to the first PDU in the PDU set 510. The first PDU may be the initial PDU or any PDU in the PDU set 510.

In some implementations, the UE 104 starts the new timer or the first discard timer for a PDU based on the second indication.

In some implementations, the first discard timer for a PDU in the PDU set expires, the UE 104 does not discard the PDCP SDU and the corresponding PDU. That means the UE 104 discards the PDCP SDU only based on the expiration of the second discard timer which is considered as legacy discard timer.

In some implementations, the UE 104 reports the information about the remaining time of the synchronization timer to the based station 102 based on a report configuration for the remaining time of the new timer by the base station 102. The UE 102 may report the information per LCG or per LCH. The new timer is configured to the UE 104 associated with a DRB or an LCH. That means the UE 104 can transmit additional delay report for the remaining synchronization time in addition to the delay report for the remaining discard time.

In some implementation, the UE 104 may transmit information about the first discard timer value or the new timer value to the base station 102. Alternatively, the UE 104 may directly transmit information about delay information related to packets of two QoS flows to the base station 102. For example, if the UE 104 reports the information about delay value of a first QoS flow relative to a second QoS flow for packets in a transmission set as assistant information to the base station 102, the base station 102 considers the value of the first discard timer, or the new timer based on the delay value.

Fig. 8 illustrates a flowchart of a method 800 that supports discarding based on a synchronization transmission set in accordance with aspects of the present disclosure. The operations of the method 800 may be implemented by a device or its components as described herein. For example, the operations of the method 800 may be performed by the UE 104 as described herein. In some implementations, the device may execute a set of instructions to control the function elements of the device to perform the described functions. Additionally, or alternatively, the device may perform aspects of the described functions using special-purpose hardware.

At 810, the UE 104 determines the synchronization transmission set. The synchronization transmission set comprises packets associated with multiple QoS flows.

In some implementations, the UE 104 may determine the packets in the synchronization transmission set based on information in headers of the packets from an upper layer of the UE 104 (such as an application layer) .

Alternatively, in some implementations, the UE 104 may determine the packets in the synchronization transmission set based on a gap between arrival time of the packets.

For example, if a gap from arrival time of a first PDU set to arrival time of a second PDU set is equal to or less than a threshold, the UE 104 may determine the first PDU set and the second PDU set as a synchronization transmission set. The maximum, minimum or range value of the gap may be configured by the base station 102 or an apparatus in the core network 106 (such as AMF or session manage function (SMF) ) .

At 820, the UE 104 discards the packets in the synchronization transmission set based on the synchronization transmission set.

Fig. 9 illustrates a flowchart of a method 900 that supports discarding based on a synchronization transmission set in accordance with aspects of the present disclosure. The operations of the method 900 may be implemented by a device or its components as described herein. The method 900 may be considered as an example implementation of the method 800. For example, the operations of the method 900 may be performed by the UE 104 as described herein. In some implementations, the device may execute a set of instructions to control the function elements of the device to perform the described functions. Additionally, or alternatively, the device may perform aspects of the described functions using special-purpose hardware.

At 910, the UE 104 may receive, from the base station 102, information about the synchronization transmission set. Examples of the information about the synchronization transmission set will be described later.

At 920, the UE 104 determines the synchronization transmission set. The synchronization transmission set comprises packets associated with multiple QoS flows.

As described above, in some implementations, the UE 104 may determine the packets in the synchronization transmission set based on information in headers of the packets from an upper layer of the UE 104 (such as an application layer) . Alternatively, in some implementations, the UE 104 may determine the packets in the synchronization transmission set based on a gap between arrival time of the packets.

At 930, the UE 104 determines a value of a first discard timer for one of the packets in the synchronization transmission set. For example, the UE 104 may determine a value of a first discard timer for an SDU corresponding to one of the packets in the synchronization transmission set.

In some implementations, the UE 104 may determine the value of the first discard timer by performing any of the methods 400, 600 and 700 as described above.

Then, the UE 104 starts the first discard timer.

At 940, if the first discard timer for one of the packets in the synchronization transmission set expires, the UE 104 may consider discard timers for all the packets in the synchronization transmission set expire and discard all the packets in the synchronization transmission set.

Hereinafter, some examples of the information about the synchronization transmission set will be described.

In some implementations, the information about the synchronization transmission set may comprise a first indication. The first indication may indicate that the UE 104 discards all the packets in the synchronization transmission set when one of the packets in the synchronization transmission set is discarded. Thus, the UE 104 may discard the packets in the synchronization transmission set based on the first indication.

In some implementations, the UE 104 may receive the first indication via a radio resource control (RRC) signaling from the base station 102.

In some implementations, the first indication may be configured per Packet Data Convergence Protocol (PDCP) entity.

Hereinafter, the first indication is also referred to as a discard indication of a synchronization transmission set for UL. For example, the discard indication of the synchronization transmission set may be synchronization PDU-sets discard indication for uplink (UL) . Synchronization PDU-sets discard indication for UL may be configured using an RRC signaling to handle the synchronization PDU-sets based discard functionality. That is, the discard indication of the synchronization transmission set may indicate whether the UE 104 discards all packets in the synchronization PDU sets when one PDU is discarded.

Alternatively, in some implementations, the information about the synchronization transmission set may comprise a second indication. The second indication may indicate that the UE 104 performs a synchronization transmission for UL.

In some implementations, the UE 104 may discard the packets in the synchronization transmission set based on the second indication. Hereinafter, the second indication is also referred to as a synchronization transmission indication for UL.

In some implementations, the synchronization transmission indication for UL together with a PDU set discard indication may be configured using an RRC signaling to handle the synchronization transmission set based discard functionality. The configuration may be per PDCP entity.

As described above, in some implementations, the synchronization transmission set may be carried on multiple DRBs. In some implementations, at least one discard timer may be managed at a PDCP layer of the UE 104 with interaction between DRBs. For example, the multiple DRBs may comprise a first DRB and a second DRB. Hereinafter, some implementations of the present disclosure will be described by taking two DRBs for example.

In some implementations, the information about the synchronization transmission set may comprise a third indication for the first DRB. The third indication may indicate that the UE 104 considers a second discard timer associated with the second DRB expires if a first discard timer associated with the first DRB expires.

In such implementations, if the first discard time expires, a first PDCP entity of the UE 104 may provide a fourth indication to a second PDCP entity of the UE 104. The fourth indication may indicate that the packets in the synchronization transmission set are to be discarded. For example, the fourth indication may comprise a sequence number (SN) of the synchronization transmission set. The first PDCP entity may be associated with the first DRB, and the second PDCP entity may be associated with the second DRB. For example, the first PDCP entity may provide the fourth indication to a MAC layer of the UE 104 and the MAC layer may provide the fourth indication to the second PDCP entity. In turn, the UE 104 may consider discard timers for all SDUs corresponding to PDUs in the synchronization transmission set expire and discard all the SDUs corresponding to PDUs in the synchronization transmission set.

Alternatively, in some implementations, the information about the synchronization transmission set may comprise a fifth indication for the first DRB and the second DRB. The fifth indication may indicate that the UE 104 considers a second discard timer associated with the second DRB expires if a first discard timer associated with the first DRB expires, or the UE 104 considers the first discard timer expires if the second discard timer expires.

In such implementations, if the first discard time expires, a first PDCP entity of the UE 104 may provide a sixth indication to a second PDCP entity of the UE 104. The sixth indication may indicate that the packets in the synchronization transmission set are to be discarded. For example, the sixth indication may comprise a sequence number (SN) of the synchronization transmission set. The first PDCP entity may be associated with the first DRB, and the second PDCP entity may be associated with the second DRB. For example, the first PDCP entity may provide the sixth indication to a MAC layer of the UE 104 and the MAC layer may provide the sixth indication to the second PDCP entity. In turn, the UE 104 may consider discard timers for all SDUs corresponding to PDUs in the synchronization transmission set expire and discard all the SDUs corresponding to PDUs in the synchronization transmission set.

In such implementations, if the UE 104 104 determines that the second discard time expires, the second PDCP entity may provide the sixth indication to the first PDCP entity. For example, the second PDCP entity may provide the sixth indication to a MAC layer of the UE 104 and the MAC layer may provide the sixth indication to the first PDCP entity. In turn, the UE 104 may consider discard timers for all SDUs corresponding to PDUs in the synchronization transmission set expire and discard all the SDUs corresponding to PDUs in the synchronization transmission set.

As described above, in some implementations, the synchronization transmission set may be carried on multiple DRBs. In some implementations, one discard timer may be managed at a MAC layer of the UE 104. The discard timer managed at the MAC layer may be separate from a discard timer in PDCP entity. Such implementations will be described with reference to Fig. 10. Fig. 10 illustrates a flowchart of a method 1000 that supports discarding based on a synchronization transmission set in accordance with aspects of the present disclosure. The operations of the method 1000 may be implemented by a device or its components as described herein. For example, the operations of the method 1000 may be performed by the UE 104 as described herein. In some implementations, the device may execute a set of instructions to control the function elements of the device to perform the described functions. Additionally, or alternatively, the device may perform aspects of the described functions using special-purpose hardware.

At 1010, the UE 104 may receive, from the base station 102, a configuration of a value of a discard timer for one of the packets in the synchronization transmission set. The discard timer is managed at a MAC layer of the UE 104. The packets in the synchronization transmission set may be carried on one or multiple DRBs. For example, the multiple DRBs may comprise a first DRB and a second DRB.

At 1020, the UE 104 determines the synchronization transmission set. The synchronization transmission set comprises packets associated with one or multiple QoS flows.

At 1030, the UE 104 sets the value of the discard timer for the synchronization transmission set at the MAC layer. Then, the UE 104 starts the discard timer.

At 1040, if the discard timer for the synchronization transmission set expires, the UE 104 may consider discard timers for all the packets in the synchronization transmission set expire and discard all the packets in the synchronization transmission set. For example, if a discard timer for a SDU corresponding to a PDU in the synchronization transmission set expires, the MAC entity may provide an indication to the first PDCP entity associated with the first DRB and the second PDCP entity associated with the second DRB. The indication may indicate that the packets in the synchronization transmission set are to be discarded. For example, the indication may comprise a sequence number (SN) of the synchronization transmission set.

It shall be understood that any of the methods 400, 600, 700, 800, 900 and 1000 may be performed in combination with or independent from the process 200.

Fig. 11 illustrates an example of a device 1100 that supports delay report and discarding based on a synchronization transmission set in accordance with aspects of the present disclosure. The device 1100 may be an example of a base station 102 or a UE 104 as described herein. The device 1100 may support wireless communication with one or more network entities 102, UEs 104, or any combination thereof. The device 1100 may include components for bi-directional communications including components for transmitting and receiving communications, such as a processor 1102, a memory 1104, a transceiver 1106, and, optionally, an I/O controller 1108. These components may be in electronic communication or otherwise coupled (e.g., operatively, communicatively, functionally, electronically, electrically) via one or more interfaces (e.g., buses) .

The processor 1102, the memory 1104, the transceiver 1106, or various combinations thereof or various components thereof may be examples of means for performing various aspects of the present disclosure as described herein. For example, the processor 1102, the memory 1104, the transceiver 1106, or various combinations or components thereof may support a method for performing one or more of the operations described herein.

In some implementations, the processor 1102, the memory 1104, the transceiver 1106, or various combinations or components thereof may be implemented in hardware (e.g., in communications management circuitry) . The hardware may include a processor, a digital signal processor (DSP) , an application-specific integrated circuit (ASIC) , a field-programmable gate array (FPGA) or other programmable logic device, a discrete gate or transistor logic, discrete hardware components, or any combination thereof configured as or otherwise supporting a means for performing the functions described in the present disclosure. In some implementations, the processor 1102 and the memory 1104 coupled with the processor 1102 may be configured to perform one or more of the functions described herein (e.g., executing, by the processor 1102, instructions stored in the memory 1104) .

For example, the processor 1102 may support wireless communication at the device 1100 in accordance with examples as disclosed herein. The processor 1102 may be configured to operable to support a means for performing the following: determining remaining time of a first discard timer for a first packet in a synchronization transmission set based on a value of the first discard timer and time of an initial transmission of a delay report, the synchronization transmission set comprising packets associated with one or multiple QoS flows; and transmitting, to a base station, the delay report comprising information about the remaining time.

In some implementations, the processor 1102 may be configured to operable to support a means for performing the following: determining a synchronization transmission set which comprises packets associated with one or multiple QoS flows; and discarding the packets in the synchronization transmission set based on the synchronization transmission set.

In some implementations, the processor 1102 may be configured to operable to support a means for performing the following: receiving a delay report from a UE, the delay report comprising information about remaining time of a first discard timer for a first packet in a synchronization transmission set, the synchronization transmission set comprising packets associated with one or multiple QoS flows; and scheduling the UE based on the delay report.

The processor 1102 may include an intelligent hardware device (e.g., a general-purpose processor, a DSP, a CPU, a microcontroller, an ASIC, an FPGA, a programmable logic device, a discrete gate or transistor logic component, a discrete hardware component, or any combination thereof) . In some implementations, the processor 1102 may be configured to operate a memory array using a memory controller. In some other implementations, a memory controller may be integrated into the processor 1102. The processor 1102 may be configured to execute computer-readable instructions stored in a memory (e.g., the memory 1104) to cause the device 1100 to perform various functions of the present disclosure.

The memory 1104 may include random access memory (RAM) and read-only memory (ROM) . The memory 1104 may store computer-readable, computer-executable code including instructions that, when executed by the processor 1102 cause the device 1100 to perform various functions described herein. The code may be stored in a non-transitory computer-readable medium such as system memory or another type of memory. In some implementations, the code may not be directly executable by the processor 1102 but may cause a computer (e.g., when compiled and executed) to perform functions described herein. In some implementations, the memory 1104 may include, among other things, a basic I/O system (BIOS) which may control basic hardware or software operation such as the interaction with peripheral components or devices.

The I/O controller 1108 may manage input and output signals for the device 1100. The I/O controller 1108 may also manage peripherals not integrated into the device M02. In some implementations, the I/O controller 1108 may represent a physical connection or port to an external peripheral. In some implementations, the I/O controller 1108 may utilize an operating system such as or another known operating system. In some implementations, the I/O controller 1108 may be implemented as part of a processor, such as the processor 1106. In some implementations, a user may interact with the device 1100 via the I/O controller 1108 or via hardware components controlled by the I/O controller 1108.

In some implementations, the device 1100 may include a single antenna 1110. However, in some other implementations, the device 1100 may have more than one antenna 1110 (i.e., multiple antennas) , including multiple antenna panels or antenna arrays, which may be capable of concurrently transmitting or receiving multiple wireless transmissions. The transceiver 1106 may communicate bi-directionally, via the one or more antennas 1110, wired, or wireless links as described herein. For example, the transceiver 1106 may represent a wireless transceiver and may communicate bi-directionally with another wireless transceiver. The transceiver 1106 may also include a modem to modulate the packets, to provide the modulated packets to one or more antennas 1110 for transmission, and to demodulate packets received from the one or more antennas 1110. The transceiver 1106 may include one or more transmit chains, one or more receive chains, or a combination thereof.

A transmit chain may be configured to generate and transmit signals (e.g., control information, data, packets) . The transmit chain may include at least one modulator for modulating data onto a carrier signal, preparing the signal for transmission over a wireless medium. The at least one modulator may be configured to support one or more techniques such as amplitude modulation (AM) , frequency modulation (FM) , or digital modulation schemes like phase-shift keying (PSK) or quadrature amplitude modulation (QAM) . The transmit chain may also include at least one power amplifier configured to amplify the modulated signal to an appropriate power level suitable for transmission over the wireless medium. The transmit chain may also include one or more antennas 1110 for transmitting the amplified signal into the air or wireless medium.

A receive chain may be configured to receive signals (e.g., control information, data, packets) over a wireless medium. For example, the receive chain may include one or more antennas 1110 for receive the signal over the air or wireless medium. The receive chain may include at least one amplifier (e.g., a low-noise amplifier (LNA) ) configured to amplify the received signal. The receive chain may include at least one demodulator configured to demodulate the receive signal and obtain the transmitted data by reversing the modulation technique applied during transmission of the signal. The receive chain may include at least one decoder for decoding the processing the demodulated signal to receive the transmitted data.

Fig. 12 illustrates an example of a processor 1200 that supports delay report and discarding based on a synchronization transmission set in accordance with aspects of the present disclosure. The processor 1200 may be an example of a processor configured to perform various operations in accordance with examples as described herein. The processor 1200 may include a controller 1202 configured to perform various operations in accordance with examples as described herein. The processor 1200 may optionally include at least one memory 1204, such as L1/L2/L3 cache. Additionally, or alternatively, the processor 1200 may optionally include one or more arithmetic-logic units (ALUs) 1200. One or more of these components may be in electronic communication or otherwise coupled (e.g., operatively, communicatively, functionally, electronically, electrically) via one or more interfaces (e.g., buses) .

The processor 1200 may be a processor chipset and include a protocol stack (e.g., a software stack) executed by the processor chipset to perform various operations (e.g., receiving, obtaining, retrieving, transmitting, outputting, forwarding, storing, determining, identifying, accessing, writing, reading) in accordance with examples as described herein. The processor chipset may include one or more cores, one or more caches (e.g., memory local to or included in the processor chipset (e.g., the processor 1200) or other memory (e.g., random access memory (RAM) , read-only memory (ROM) , dynamic RAM (DRAM) , synchronous dynamic RAM (SDRAM) , static RAM (SRAM) , ferroelectric RAM (FeRAM) , magnetic RAM (MRAM) , resistive RAM (RRAM) , flash memory, phase change memory (PCM) , and others) .

The controller 1202 may be configured to manage and coordinate various operations (e.g., signaling, receiving, obtaining, retrieving, transmitting, outputting, forwarding, storing, determining, identifying, accessing, writing, reading) of the processor 1200 to cause the processor 1200 to support various operations in accordance with examples as described herein. For example, the controller 1202 may operate as a control unit of the processor 1200, generating control signals that manage the operation of various components of the processor 1200. These control signals include enabling or disabling functional units, selecting data paths, initiating memory access, and coordinating timing of operations.

The controller 1202 may be configured to fetch (e.g., obtain, retrieve, receive) instructions from the memory 1204 and determine subsequent instruction (s) to be executed to cause the processor 1200 to support various operations in accordance with examples as described herein. The controller 1202 may be configured to track memory address of instructions associated with the memory 1204. The controller 1202 may be configured to decode instructions to determine the operation to be performed and the operands involved. For example, the controller 1202 may be configured to interpret the instruction and determine control signals to be output to other components of the processor 1200 to cause the processor 1200 to support various operations in accordance with examples as described herein. Additionally, or alternatively, the controller 1202 may be configured to manage flow of data within the processor 1200. The controller 1202 may be configured to control transfer of data between registers, arithmetic logic units (ALUs) , and other functional units of the processor 1200.

The memory 1204 may include one or more caches (e.g., memory local to or included in the processor 1200 or other memory, such RAM, ROM, DRAM, SDRAM, SRAM, MRAM, flash memory, etc. In some implementation, the memory 1204 may reside within or on a processor chipset (e.g., local to the processor 1200) . In some other implementations, the memory 1204 may reside external to the processor chipset (e.g., remote to the processor 1200) .

The memory 1204 may store computer-readable, computer-executable code including instructions that, when executed by the processor 1200, cause the processor 1200 to perform various functions described herein. The code may be stored in a non-transitory computer-readable medium such as system memory or another type of memory. The controller 1202 and/or the processor 1200 may be configured to execute computer-readable instructions stored in the memory 1204 to cause the processor 1200 to perform various functions. For example, the processor 1200 and/or the controller 1202 may be coupled with or to the memory 1204, the processor 1200, the controller 1202, and the memory 1204 may be configured to perform various functions described herein. In some examples, the processor 1200 may include multiple processors and the memory 1204 may include multiple memories. One or more of the multiple processors may be coupled with one or more of the multiple memories, which may, individually or collectively, be configured to perform various functions herein.

The one or more ALUs 1200 may be configured to support various operations in accordance with examples as described herein. In some implementation, the one or more ALUs 1200 may reside within or on a processor chipset (e.g., the processor 1200) . In some other implementations, the one or more ALUs 1200 may reside external to the processor chipset (e.g., the processor 1200) . One or more ALUs 1200 may perform one or more computations such as addition, subtraction, multiplication, and division on data. For example, one or more ALUs 1200 may receive input operands and an operation code, which determines an operation to be executed. One or more ALUs 1200 be configured with a variety of logical and arithmetic circuits, including adders, subtractors, shifters, and logic gates, to process and manipulate the data according to the operation. Additionally, or alternatively, the one or more ALUs 1200 may support logical operations such as AND, OR, exclusive-OR (XOR) , not-OR (NOR) , and not-AND (NAND) , enabling the one or more ALUs 1200 to handle conditional operations, comparisons, and bitwise operations.

The processor 1200 may support wireless communication in accordance with examples as disclosed herein. The processor 1200 may be configured to operable to support a means for performing the following: determining remaining time of a first discard timer for a first packet in a synchronization transmission set based on a value of the first discard timer and time of an initial transmission of a delay report, the synchronization transmission set comprising packets associated with one or multiple QoS flows; and transmitting, to a base station, the delay report comprising information about the remaining time.

In some implementations, the processor 1200 may be configured to operable to support a means for performing the following: determining a synchronization transmission set which comprises packets associated with one or multiple QoS flows; and discarding the packets in the synchronization transmission set based on the synchronization transmission set.

In some implementations, the processor 1200 may be configured to operable to support a means for performing the following: receiving a delay report from a UE, the delay report comprising information about remaining time of a first discard timer for a first packet in a synchronization transmission set, the synchronization transmission set comprising packets associated with one or multiple QoS flows; and scheduling the UE based on the delay report.

Fig. 13 illustrates a flowchart of a method 1300 that supports delay report in accordance with aspects of the present disclosure. The operations of the method 1300 may be implemented by a device or its components as described herein. For example, the operations of the method 13 may be performed by a UE 104 as described herein. In some implementations, the device may execute a set of instructions to control the function elements of the device to perform the described functions. Additionally, or alternatively, the device may perform aspects of the described functions using special-purpose hardware.

At 1310, the method may include determining remaining time of a first discard timer for a first packet in a synchronization transmission set based on a value of the first discard timer and time of an initial transmission of a delay report, the synchronization transmission set comprising packets associated with one or multiple QoS flows. The operations of 1310 may be performed in accordance with examples as described herein. In some implementations, aspects of the operations of 1310 may be performed by a device as described with reference to Fig. 1.

At 1320, the method may include transmitting, to a base station, the delay report comprising information about the remaining time. The operations of 1320 may be performed in accordance with examples as described herein. In some implementations, aspects of the operations of 1320 may be performed by a device as described with reference to Fig. 1.

Fig. 14 illustrates a flowchart of a method 1400 that supports delay report in accordance with aspects of the present disclosure. The operations of the method 1400 may be implemented by a device or its components as described herein. For example, the operations of the method 14 may be performed by a UE 104 as described herein. In some implementations, the device may execute a set of instructions to control the function elements of the device to perform the described functions. Additionally, or alternatively, the device may perform aspects of the described functions using special-purpose hardware.

At 1410, the method may include receiving a delay report from a UE, the delay report comprising information about remaining time of a first discard timer for a first packet in a synchronization transmission set, the synchronization transmission set comprising packets associated with one or multiple QoS flows. The operations of 1410 may be performed in accordance with examples as described herein. In some implementations, aspects of the operations of 1410 may be performed by a device as described with reference to Fig. 1.

At 1420, the method may include scheduling the UE based on the delay report. The operations of 1420 may be performed in accordance with examples as described herein. In some implementations, aspects of the operations of 1420 may be performed by a device as described with reference to Fig. 1.

It shall be noted that implementations of the present disclosure which have been described with reference to Figs. 2 to 10 are also applicable to the device 1100, the process 1200 and the methods 1300 and 1400.

It should be noted that the methods described herein describes possible implementations, and that the operations and the steps may be rearranged or otherwise modified and that other implementations are possible. Further, aspects from two or more of the methods may be combined.

The various illustrative blocks and components described in connection with the disclosure herein may be implemented or performed with a general-purpose processor, a DSP, an ASIC, a CPU, an FPGA or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. A general-purpose processor may be a microprocessor, but in the alternative, the processor may be any processor, controller, microcontroller, or state machine. A processor may also be implemented as a combination of computing devices (e.g., a combination of a DSP and a microprocessor, multiple microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration.

The functions described herein may be implemented in hardware, software executed by a processor, firmware, or any combination thereof. If implemented in software executed by a processor, the functions may be stored on or transmitted over as one or more instructions or code on a computer-readable medium. Other examples and implementations are within the scope of the disclosure and appended claims. For example, due to the nature of software, functions described herein may be implemented using software executed by a processor, hardware, firmware, hardwiring, or combinations of any of these. Features implementing functions may also be physically located at various positions, including being distributed such that portions of functions are implemented at different physical locations.

Computer-readable media includes both non-transitory computer storage media and communication media including any medium that facilitates transfer of a computer program from one place to another. A non-transitory storage medium may be any available medium that may be accessed by a general-purpose or special-purpose computer. By way of example, non-transitory computer-readable media may include RAM, ROM, electrically erasable programmable ROM (EEPROM) , flash memory, compact disk (CD) ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other non-transitory medium that may be used to carry or store desired program code means in the form of instructions or data structures and that may be accessed by a general-purpose or special-purpose computer, or a general-purpose or special-purpose processor.

As used herein, including in the claims, an article “a” before an element is unrestricted and understood to refer to “at least one” of those elements or “one or more” of those elements. The terms “a, ” “at least one, ” “one or more, ” and “at least one of one or more” may be interchangeable. As used herein, including in the claims, “or” as used in a list of items (e.g., a list of items prefaced by a phrase such as “at least one of” or “one or more of” or “one or both of” ) indicates an inclusive list such that, for example, a list of at least one of A, B, or C means A or B or C or AB or AC or BC or ABC (i.e., A and B and C) . Also, as used herein, the phrase “based on” shall not be construed as a reference to a closed set of conditions. For example, an example step that is described as “based on condition A” may be based on both a condition A and a condition B without departing from the scope of the present disclosure. In other words, as used herein, the phrase “based on” shall be construed in the same manner as the phrase “based at least in part on. Further, as used herein, including in the claims, a “set” may include one or more elements.

The description herein is provided to enable a person having ordinary skill in the art to make or use the disclosure. Various modifications to the disclosure will be apparent to a person having ordinary skill in the art, and the generic principles defined herein may be applied to other variations without departing from the scope of the disclosure. Thus, the disclosure is not limited to the examples and designs described herein but is to be accorded the broadest scope consistent with the principles and novel features disclosed herein.

Claims

A user equipment (UE) , comprising:

a processor; and

a transceiver coupled to the processor,

wherein the processor is configured to:

determine remaining time of a first timer for a first packet in a synchronization transmission set based on a value of the first timer and the time of an initial transmission of a delay report; and

transmit, via the transceiver to a base station, the delay report comprising information about the remaining time.
The UE of claim 1, wherein the first timer comprises a discard timer or a synchronization timer.
The UE of claim 1, wherein the processor is further configured to:

determine the value of the first timer based on arrival time or arrival orders of the first packet and a second packet in the synchronization transmission set.
The UE of claim 3, wherein the processor is configured to determine the value of the first timer by:

receiving, via the transceiver from the base station, a configuration of multiple values of the first timer; and

determining, based on the arrival time or the arrival orders, one of the multiple values as the value of the first timer.
The UE of claim 3, wherein the processor is configured to determine the value of the first timer by:

receiving, via the transceiver from the base station, a configuration of a first value of the first timer associated with a data radio bearer (DRB) ; and

determining the value of the first timer based on the first value of the first timer and the arrival time or the arrival orders.
The UE of claim 3, wherein:

the processor is configured to determine the value of the first timer by:

receiving, via the transceiver from the base station, a first configuration of a first value of the first timer; and

the processor is further configured to:

receive, via the transceiver from the base station, a second configuration of a second value of a second discard timer for the first packet associated with a data radio bearer (DRB) ;

start the second discard timer for the first packet based on the second configuration; and

based on determining that first arrival time of the first packet is later than second arrival time of the second packet, start the first timer for the first packet based on the first configuration.
The UE of claim 4, 5, or 6, wherein the processor is configured to start the first timer for the first packet by:

based on determining that the first arrival time of the first packet is later than the second arrival time of the second packet by a second number of time units, starting the first timer for the first packet.
The UE of claim 1, wherein the processor is further configured to:

determine the synchronization transmission set; and

discard the packets in the synchronization transmission set based on the synchronization transmission set.
The UE of claim 1, wherein the processor is further configured to:

receive a second indication via the transceiver from the base station, the second indication indicating that the UE performs a synchronization transmission for uplink.
The UE of claim 9, wherein the processor is further configured to:

start the first timer for the first packet based on the second indication.
The UE of claim 9, wherein the processor is further configured to:

discard the packets in the synchronization transmission set based on the second indication.
The UE of claim 8, wherein the processor is configured to determine the synchronization transmission set by:

determine the packets in the synchronization transmission set based on a gap between arrival time of the packets.
The UE of claim 1, wherein the processor is further configured to:

determine arrival time or arrival orders of a first packet and a second packet in the synchronization transmission set; and

transmit, via the transceiver to the base station, information about the arrival time, delay information or the arrival orders.
The UE of claim 3 or 13, wherein the first packet is associated with a first QoS flow or a first data radio bearer (DRB) , and the second packet is associated with a second QoS flow or a second DRB.
A user equipment (UE) , comprising:

a processor; and

a transceiver coupled to the processor,

wherein the processor is configured to:

determine a synchronization transmission set; and

discard the packets in the synchronization transmission set based on the synchronization transmission set.
A base station, comprising:

a processor; and

a transceiver coupled to the processor,

wherein the processor is configured to:

receive a delay report via the transceiver from a user equipment (UE) , the delay report comprising information about remaining time of a first timer for a first packet (s) in a synchronization transmission set; and

schedule the UE based on the delay report.
The base station of claim 16, wherein the processor is further configured to:

transmit, via the transceiver to the UE, a configuration of a value of the first timer.
The base station of claim 16, wherein the processor is further configured to:

transmit a first indication via the transceiver to the UE, the first indication indicating that the UE discards all the packets in the synchronization transmission set when one of the packets in the synchronization transmission set is discarded.
The base station of claim 16, wherein the processor is further configured to:

transmit a second indication via the transceiver to the UE, the second indication indicating that the UE performs a synchronization transmission for uplink.
A processor for wireless communication, comprising:

at least one memory; and

a controller coupled with the at least one memory and configured to cause the controller to:

determine remaining time of a first timer for a first packet in a synchronization transmission set based on a value of the first timer and time of an initial transmission of a delay report; and

transmit, to a base station, the delay report comprising information about the remaining time.