Processing of scheduling requests (SR)

Abstract

The present application relates to improved user equipment (UE) behavior in instances of buffer status reporting (BSR) or other Medium Access Control (MAC) Control Elements (CEs) triggered by a particular event, such as packet drop or long packet queuing delay time. In some cases, a UE may avoid unnecessary scheduling request (SR) signaling, e.g., if a pending SR has existent, the UE may cancel the SR if data in the buffer is no longer available due to packet discard. In other cases, if a pending SR has been present, the UE may signal the pending SR to the base station as soon as possible and provide a buffer state update. When a BSR is triggered by a long packet queuing delay and a pending SR has existent, the UE may also want to signal the pending SR as soon as possible to provide packet queuing delay time information.

Description

Technical Field

[0001] The present application relates to wireless devices and wireless networks, including user equipment, terminals, circuits, computer-readable media, and methods for handling scheduling requests (SRs) in the presence of packet drops and / or long packet queuing delay times. Background Art

[0002] The use of wireless communication systems is growing rapidly. In recent years, wireless devices such as smartphones and tablet computers have become increasingly sophisticated. In addition to supporting phone calls, many mobile devices now also provide access to the Internet, email, text messaging, and navigation using the Global Positioning System (GPS), and are capable of operating sophisticated applications that utilize these functionalities. Additionally, there are many different wireless communication technologies and wireless communication standards. Some examples of wireless communication standards include GSM, UMTS (e.g., associated with WCDMA or TD-SCDMA air interfaces), Long Term Evolution (LTE), Advanced LTE (LTE-A), HSPA, 3GPP2 CDMA2000 (e.g., 1xRTT, 1xEV-DO, HRPD, eHRPD), IEEE 802.11 (WLAN or Wi-Fi), and Bluetooth. TM etc.

[0003] The introduction of an ever-increasing number of features and functionalities in wireless communication devices has also created a continuous demand for improvements in wireless communication and improved wireless communication devices. In order to increase coverage and better serve the increasing demand and scope of intended uses of wireless communication, in addition to the above-mentioned communication standards, there are also wireless communication technologies under development, including the fifth generation (5G) standard and the new radio (NR) communication technology. Therefore, there is a need for improvements in the field that support such development and design.

[0004] Specifically, the Buffer Status Report (BSR) is an important mechanism for a user equipment (UE) to inform the base station about the amount of uplink data that has arrived in the UE's buffer. The base station can use this information to allocate uplink resources to accommodate the buffered data. Details on the use of Buffer Status Reports in Third Generation Partnership Project (3GPP) networks are provided in 3GPP Technical Specification 38.300 v17.2.0 (2022-10-01).

[0005] Media streams can now be carried over wireless networks, but the delivery of media content can be particularly challenging for applications with high throughput and low latency requirements, such as video conferencing and so-called extended reality (XR) applications, where XR is defined as an umbrella term referring to all aspects of virtual reality (VR), augmented reality (AR), and / or mixed reality (MR). Wireless networks can implement technologies to improve network capacity and energy efficiency, as well as reduce the impact of packet loss on users.

[0006] For example, the network should be able to process groups of packets based on how critical the packets are to the user experience. Some groups of data packets hold application data units that are processed (e.g., decoded) together by an application. 3GPP defines the term "protocol data unit set" (or "PDU set") to identify these groups of data packets that carry a payload of application data units, which may correspond to data packets of network application layer (NAL) units. Application data units may depend on other application data units to be processed or decoded by an application (e.g., P frames depend on I frames, and higher layers depend on lower layers, etc.).

[0007] The network can perform differentiated processing of groups of data packets, for example, prioritizing the transmission of some groups of packets over other groups in the event of network congestion. The network can also selectively discard data packets depending on which application data units have been lost. The network can also strategically limit the wake-up time (i.e., the time the radio is awake) to send and receive data. Thus, the packet scheduler can benefit from information about the size and periodicity of the traffic, as well as the delay budget and expected jitter of a specific application. Therefore, efficient processing of high-throughput and low-latency traffic can include differentiated processing of groups of packets and configuration of low-layer scheduling.

[0008] In the case of high-throughput and low-latency applications (such as XR applications), it has been proposed that the BSR should be enhanced to include information such as packet queuing delay time and / or the remaining time until the upcoming delivery deadline. This information will allow the base station to allocate uplink resources in a more timely manner. In view of this, new BSR triggering events related to packet drops or long queuing times may exist. These types of BSRs should ideally be transmitted to the base station very urgently. Summary of the Invention

[0009] According to one or more embodiments, disclosed herein is a method of operating a user equipment (UE), the method comprising: detecting a condition of a buffer of the UE corresponding to a first buffer condition; determining a first logical channel (LCH) associated with the first buffer condition; determining whether there is a first scheduling request (SR) pending for the first LCH; and in response to determining that there is a first SR pending for the first LCH, modifying at least one parameter of the first SR pending for the first LCH; however, in response to determining that there is no first SR pending for the first LCH, triggering a second SR for the first LCH, wherein the second SR has at least one parameter modified relative to a parameter for a default SR configuration corresponding to the first LCH.

[0010] According to some aspects, the first buffer condition triggers a first buffer status report (BSR) or other medium access control (MAC) control element (CE), which may be sent to the base station. In some aspects, the first BSR may report information only for the first LCH, while in other aspects, the first BSR may report information for each LCH in the logical channel group (LCG) associated with the first LCH. According to some such aspects, triggering the second SR further includes triggering the second SR to obtain an uplink (UL) resource allocation for the first BSR. In some aspects, triggering the second SR may be performed in response to determining that there is no uplink shared channel (UL-SCH) available for use by the UE.

[0011] According to other aspects, the first buffer condition may be based on at least one of: (a) determining whether the application requires all PDUs in the buffered protocol data unit (PDU) set; (b) comparing the remaining time until the delivery deadline of the buffered data with a predetermined threshold; (c) comparing the queuing time of the buffered data with a predetermined threshold; (d) comparing the amount of buffered data with a predetermined threshold; (e) the importance or priority associated with the buffered PDU set; (f) whether the packet drop is configured for the buffered PDU set or the radio bearer corresponding to the buffered PDU set; (g) whether a packet drop event has occurred; (h) comparing the amount of dropped data with a predetermined threshold; (i) comparing the amount of buffered data remaining after the packet drop event has occurred with a predetermined threshold; or (j) determining whether the amount of buffered data remaining after the packet drop event is zero.

[0012] According to yet other aspects, the method further includes determining that the first buffer condition comprises a packet queuing delay condition or a packet drop condition. In instances where the first buffer condition relates to a packet queuing delay, the method further includes transmitting packet queuing delay time information to a base station. In some such instances, the first buffer condition may indicate at least one of the following conditions: (a) a queuing delay for the buffered data has exceeded a threshold; or (b) an amount of time remaining until a delivery deadline for the buffered data is less than a threshold (where, for example, the delivery deadline for the buffered data is derived at least in part based on a delay budget associated with one or more packets within the buffered data).

[0013] According to yet other aspects, modifying at least one parameter of the first SR pending for the first LCH includes at least one of: (a) stopping an inhibit timer for the first SR; (b) canceling the first SR; (c) triggering a new SR with a different SR configuration than the first SR (e.g., a shorter inhibit timer); (d) modifying a physical uplink control channel (PUCCH) configuration used to signal the first SR; or (e) resetting a value of a counter for the first SR.

[0014] According to still other aspects, signaling the first SR can be accomplished at the next available opportunity (ie, regardless of whether the SR inhibit timer for the first SR is still running).

[0015] According to yet other aspects, a medium access control (MAC) layer may instruct the UE to use a physical layer (PHY) to signal the first SR directly to a base station.

[0016] According to yet other aspects, the second SR having at least one parameter modified relative to a parameter for a default SR configuration includes at least one of: (a) the second SR having an SR configuration different from the default SR configuration; (b) the second SR having an SR inhibit timer configuration different from the default SR configuration (e.g., a shorter inhibit timer); or (c) the second SR uses a PUCCH configuration different from the default SR configuration.

[0017] According to yet other aspects, the buffer may include services for multiple LCHs of one or more logical channel groups (LCGs), wherein the first buffer condition is associated with one or more of the multiple LCHs or with any of the multiple LCHs.

[0018] The various methods and techniques outlined in this section may also be performed by a UE device comprising: a receiver; a transmitter; and a processor configured to perform any of the various methods and techniques outlined herein. The various methods and techniques outlined in this section may also be stored as instructions on a non-transitory computer-readable medium, where these instructions, when executed, cause the various methods and techniques outlined herein to be performed.

[0019] This summary is intended to provide a brief overview of some of the subject matter described in this document. Therefore, it should be understood that the aforementioned features are merely examples and should not be construed as narrowing the scope or spirit of the subject matter described herein in any way. Other features, aspects, and advantages of the subject matter described herein will become apparent from the following detailed description, accompanying drawings, and claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] A better understanding of the present subject matter may be gained when the following detailed description of the various aspects is considered in conjunction with the following drawings:

[0021] Figure 1

[0014] An example wireless communication system according to some aspects is illustrated.

[0022] Figure 2

[0014] Another example of a wireless communication system in accordance with some aspects is illustrated.

[0023] Figure 3 An example block diagram of a UE is illustrated in accordance with some aspects.

[0024] Figure 4 Illustrated is an example block diagram of a base station (BS) in accordance with some aspects.

[0025] Figure 5 A diagram illustrating a method for exchanging buffer status reports (BSRs) and uplink grants between a UE and a base station in accordance with some aspects is described in detail.

[0026] Figure 6 Example PDU sets containing different numbers of data packets according to some aspects are illustrated.

[0027] Figure 7 A flow chart detailing a method for handling a scheduling request (SR) when a BSR is triggered by packet drop or long packet queuing delay is illustrated in accordance with some aspects.

[0028] Figure 8 Various diagrams illustrating exemplary SR configurations for handling a BSR triggered by packet drops or long packet queuing delays are illustrated in detail according to some aspects.

[0029] Figure 9is a flow chart detailing a method for handling a BSR when the BSR is triggered by packet drop or long packet queuing delay, according to some aspects.

[0030] While the features described herein are susceptible to various modifications and alternative forms, specific aspects thereof are shown by way of example in the drawings and described in detail herein. It should be understood, however, that the drawings and detailed description thereof are not intended to be limiting to the particular forms disclosed, but, on the contrary, are intended to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the subject matter as defined by the appended claims. DETAILED DESCRIPTION

[0031] The present application relates to improved user equipment (UE) behavior in instances of a buffer status report (BSR) triggered by an event related to packet drop or long packet queuing delay. In some cases, the UE can avoid unnecessary scheduling request (SR) signaling. For example, if there is already a pending SR, the UE can cancel the SR if data in the buffer is no longer available due to packet drop. In other cases where there is already a pending SR, the UE can signal the pending SR as soon as possible to transmit the BSR to the base station and provide timely buffer status updates. When the BSR is triggered by a long packet queuing delay and there is already a pending SR, the UE may also want to signal the pending SR as soon as possible to transmit a medium access control (MAC) control element (CE) (such as a BSR) to the base station and provide packet queuing delay information. (Note that in some implementations, packet queuing delay information can also be conveyed to the network via other types of MAC CEs (i.e., MAC CEs other than BSRs).) If there is no pending SR, the UE can trigger a new SR to obtain suitable uplink (UL) resources for the BSR.

[0032] The following is a glossary of additional terms that may be used in this disclosure:

[0033] Memory medium – Any of various types of non-transitory memory devices or storage devices. The term “memory medium” is intended to include installation media (e.g., CD-ROM, floppy disk, or tape device; computer system memory or random access memory, such as DRAM, DDR RAM, SRAM, EDO RAM, Rambus RAM), non-volatile memory, such as Flash, magnetic media (e.g., hard drive or optical storage device; registers or other similar types of memory elements). Memory media may also include other types of non-transitory memory or a combination thereof. Furthermore, the memory medium may be located in a first computer system executing a program, or may be located in a different second computer system connected to the first computer system via a network (such as the Internet). In the latter example, the second computer system may provide program instructions to the first computer for execution. The term “memory medium” may include two or more memory media that may reside in different locations (e.g., in different computer systems connected via a network). The memory medium may store program instructions (e.g., represented as a computer program) that may be executed by one or more processors.

[0034] Carrier Medium—memory media as described above, as well as physical transmission media such as a bus, network, and / or other physical transmission media that convey signals such as electrical, electromagnetic, or digital signals.

[0035] Programmable hardware elements - include various hardware devices that include multiple programmable function blocks connected via programmable interconnects. Examples include FPGAs (field programmable gate arrays), PLDs (programmable logic devices), FPOAs (field programmable object arrays), and CPLDs (complex PLDs). Programmable function blocks can range from fine-grained (combinatorial logic or lookup tables) to coarse-grained (arithmetic logic units or processor cores). Programmable hardware elements may also be referred to as "configurable logic units."

[0036] User Equipment (UE) (also called "user device," "UE device," or "terminal") - any of various types of computer systems or devices that are mobile or portable and that perform wireless communication. Examples of UE devices include mobile phones or smartphones (e.g., iPhones). TM , based on Android TM phones), portable gaming devices (e.g., Nintendo Switch TM 、Nintendo DS TM PlayStation Vita TM PlayStation Portable TM 、Gameboy AdvanceTM , iPhone TM ), laptops, wearable devices (e.g., smart watches, smart glasses), PDAs, portable internet devices, music players, data storage devices, other handheld devices, in-vehicle infotainment (IVI), in-car entertainment (ICE) devices, instrument clusters, heads-up display (HUD) devices, on-board diagnostic (OBD) devices, dashboard mobile equipment (DME), mobile data terminals (MDT), electronic engine management systems (EEMS), electronic / engine control units (ECUs), electronic / engine control modules (ECMs), embedded systems, microcontrollers, control modules, engine management systems (EMS), connected or “smart” appliances, machine type communication (MTC) devices, machine-to-machine (M2M) and Internet of Things (IoT) devices, etc. In general, the term “UE” or “UE device” or “terminal” or “user equipment” may be broadly defined to encompass any electronic, computing and / or telecommunication device (or combination of devices) that is easily transportable by a user (or vehicle) and capable of wireless communication.

[0037] Wireless Device—Any of various types of computer systems or devices that perform wireless communications. A wireless device may be portable (or mobile), or may be stationary or fixed in place. A UE is an example of a wireless device.

[0038] Communication Device – Any of various types of computer systems or devices that perform communication, where the communication can be wired or wireless. A communication device can be portable (or mobile), or it can be stationary or fixed in place. A wireless device is one example of a communication device. A UE is another example of a communication device.

[0039] Base Station – The terms “base station,” “wireless base station,” or “wireless station” have the full scope of their ordinary meaning and include at least a wireless communication station installed at a fixed location and used to communicate as part of a wireless telephone system or radio system. For example, if a base station is implemented in the context of LTE, it may alternatively be referred to as an “eNodeB” or “eNB.” If a base station is implemented in the context of 5G NR, it may alternatively be referred to as a “gNodeB” or “gNB.” Although certain aspects are described in the context of LTE or 5G NR, references to “eNB,” “gNB,” “nodeB,” “base station,” and “NB” may also refer to one or more wireless nodes that serve a cell to provide wireless connectivity between user equipment and a generally wider network, and the concepts discussed are not limited to any particular wireless technology. Although certain aspects are described in the context of LTE or 5G NR, references to “eNB,” “gNB,” “nodeB,” “base station,” and “NB” are not intended to limit the concepts discussed herein to any particular wireless technology, and the concepts discussed are applicable to any wireless system.

[0040] Node—The term “node” or “wireless node” as used herein may refer to one or more devices associated with a cell that provides wireless connectivity between user equipment and a typically wired network.

[0041] Processing element (or processor) – refers to any of the various elements or combinations of elements that are capable of performing functions in a device, such as user equipment or a cellular network device. A processing element may include, for example, a processor and associated memory, portions or circuits of individual processor cores, an entire processor core, a separate processor, an array of processors, circuits such as an application-specific integrated circuit (ASIC), programmable hardware elements such as a field-programmable gate array (FPGA), and various combinations thereof.

[0042] Channel - a medium used to transport information from a transmitter (sender) to a receiver. It should be noted that since the characteristics of the term "channel" may vary according to different wireless protocols, the term "channel" as used herein may be considered to be used in a manner that is consistent with the standard of the type of device to which the term is used. In some standards, the channel width may be variable (e.g., depending on device capabilities and frequency band conditions, etc.). For example, LTE may support scalable channel bandwidths of 1.4MHz to 20MHz. A WLAN channel may be 22MHz wide, while a Bluetooth channel may be 1Mhz wide. Other protocols and standards may include different definitions of channels. In addition, some standards may define and use multiple types of channels (e.g., different channels for uplink or downlink and / or different channels for different purposes (such as data and control information, etc.)).

[0043] Frequency band - The term "frequency band" has the full breadth of its ordinary meaning and includes at least a segment of the spectrum (eg, radio frequency spectrum) in which channels are used or set aside for the same purpose.

[0044] Configured to - Various components may be described as being "configured to" perform one or more tasks. In such contexts, "configured to" is a broad statement that generally means "having a structure" to perform one or more tasks during operation. Thus, a component can be configured to perform a task even when the component is not currently performing the task (e.g., a set of electrical conductors can be configured to electrically connect a module to another module even when the two modules are not connected). In some contexts, "configured to" can be a broad statement that generally means "having a structure" to carry out one or more tasks during operation. Thus, a component can be configured to perform a task even when the component is not currently turned on. Generally, the circuitry that forms the structure corresponding to "configured to" may include hardware circuitry.

[0045] For ease of description, various components may be described as performing one or more tasks. Such descriptions should be interpreted as including the phrase "configured to." Representing a component as being configured to perform one or more tasks expressly intends that the component not be interpreted under 35 U.S.C. §112(f).

[0046] Example Wireless Communication System

[0047] Now go to Figure 1 , illustrates a simplified example of a wireless communication system according to some aspects. Note that, Figure 1 The systems are merely non-limiting examples of possible systems, and features of the present disclosure may be implemented in any of a variety of systems as desired.

[0048] As shown, the example wireless communication system includes a base station 102A that communicates with one or more user devices 106A and 106B to 106N via a transmission medium. Each of the user devices may be referred to herein as a "user equipment" (UE). Accordingly, user device 106 is referred to as a UE or UE device.

[0049] The base station (BS) 102A may be a base transceiver station (BTS) or a cell site (eg, a "cellular base station") and may include hardware that enables wireless communications with the UEs 106A- 106N.

[0050] The communication area (or coverage area) of a base station may be referred to as a "cell". The base station 102A and the UE 106 may be configured to communicate over a transmission medium using any of a variety of radio access technologies (RATs), also known as wireless communication technologies or telecommunication standards, such as GSM, UMTS (associated with, for example, WCDMA or TD-SCDMA air interfaces), LTE, LTE-A, 5G NR, HSPA, 3GPP2 CDMA2000. Note that if the base station 102A is implemented in the context of LTE, it may alternatively be referred to as an "eNodeB" or "eNB". Note that if the base station 102A is implemented in the context of 5G NR, it may alternatively be referred to as a "gNodeB" or "gNB".

[0051] In some aspects, UE 106 may be an IoT UE that may include a network access layer designed for low-power IoT applications that utilize short-term UE connections. The IoT UE may utilize technologies such as M2M or MTC to exchange data with an MTC server or device via a public land mobile network (PLMN), proximity service (ProSe), or device-to-device (D2D) communication, a sensor network, or an IoT network. M2M or MTC data exchange may be machine-initiated data exchange. An IoT network describes interconnected IoT UEs that may include uniquely identifiable embedded computing devices (within the Internet infrastructure) with short-term connections. As an example, vehicle-to-everything (V2X) may utilize ProSe features using an SL interface to communicate directly between devices. The IoT UE may also execute background applications (e.g., keep-alive messages, status updates, etc.) to facilitate connectivity to the IoT network.

[0052] As shown, UEs 106 (such as UE 106A and UE 106B) may directly exchange communication data via a SL interface 108. The SL interface 108 may be a PC5 interface that includes one or more physical channels, including but not limited to a physical sidelink shared channel (PSSCH), a physical sidelink control channel (PSCCH), a physical sidelink broadcast channel (PSBCH), and a physical sidelink feedback channel (PSFCH).

[0053] In a V2X scenario, one or more of base stations 102 may be a roadside unit (RSU) or function as an RSU. The term RSU may refer to any transportation infrastructure entity used for V2X communications. An RSU may be implemented in or by a suitable wireless node or stationary (or relatively stationary) UE. An RSU implemented in or by a UE may be referred to as a "UE-type RSU," an RSU implemented in or by an eNB may be referred to as an "eNB-type RSU," an RSU implemented in or by a gNB may be referred to as a "gNB-type RSU," and so on. In one example, an RSU is a computing device coupled to radio frequency circuitry located on the roadside that provides connectivity support to passing vehicle UEs (vUEs). The RSU may also include internal data storage circuitry for storing intersection map geometry, traffic statistics, media, and applications / software for sensing and controlling ongoing vehicular and pedestrian traffic. The RSU may operate on the 5.9 GHz Intelligent Transportation System (ITS) band to provide extremely low latency communications required for high-speed events, such as collision avoidance and traffic warnings. Additionally or alternatively, the RSU may operate on the cellular V2X band to provide the aforementioned low latency communications as well as other cellular communication services. Additionally or alternatively, the RSU may operate as a Wi-Fi hotspot (2.4 GHz band) and / or provide connectivity with one or more cellular networks to provide uplink and downlink communications. Some or all of the RF circuits of the computing device and the RSU may be enclosed in a weatherproof enclosure suitable for outdoor installation and may include a network interface controller to provide a wired connection (e.g., Ethernet) to a traffic signal controller and / or backhaul network.

[0054] As shown, base station 102A may also be configured to communicate with network 100 (e.g., a cellular service provider's core network, a telecommunications network such as the Public Switched Telephone Network (PSTN) and / or the Internet, among other possibilities). Thus, base station 102A may facilitate communications between user devices and / or between user devices and network 100. Specifically, cellular base station 102A may provide UE 106 with various telecommunications capabilities, such as voice, SMS, and / or data services.

[0055] Base station 102A and other similar base stations (such as base stations 102B to 102N) operating according to the same or different cellular communication standards can thus be provided as a network of cells that can provide continuous or nearly continuous overlapping service to UEs 106A to 106N and similar devices over a geographic area via one or more cellular communication standards.

[0056] Thus, although base station 102A may function as Figure 1The illustrated "serving cell" of UEs 106A to 106N, each UE 106 may also be able to receive signals from (and possibly be within communication range of) one or more other cells (which may be provided by base stations 102B to 102N and / or any other base stations), which may be referred to as "neighboring cells." Such cells may also be able to facilitate communications between user devices and / or between user devices and network 100. Such cells may include "macro" cells, "micro" cells, "pico" cells, and / or cells of any other variety of granularity of service area size. For example, Figure 1 The illustrated base stations 102A and 102B may be macro cells, while the base station 102N may be a micro cell. Other configurations are also possible.

[0057] In some aspects, the base station 102A may be a next generation base station (e.g., a 5G New Radio (5GNR) base station or "gNB"). In some aspects, the gNB may be connected to a legacy evolved packet core (EPC) network and / or to an NR core (NRC) / 5G core (5GC) network. In addition, a gNB cell may include one or more transition and reception points (TRPs). In addition, a UE capable of operating in accordance with 5GNR may be connected to one or more TRPs within one or more gNBs. For example, the base station 102A and one or more other base stations 102 may support joint transmissions such that the UE 106 may be able to receive transmissions from multiple base stations (and / or multiple TRPs provided by the same base station). For example, as Figure 1 As illustrated, base station 102A and base station 102C are both shown serving UE 106A.

[0058] It is noted that the UE 106 may be capable of communicating using multiple wireless communication standards. For example, in addition to at least one of the cellular communication protocols discussed in the above definitions, the UE 106 may also be configured to communicate using wireless networking (e.g., Wi-Fi) and / or peer-to-peer wireless communication protocols (e.g., Bluetooth and Wi-Fi peer-to-peer, etc.). If desired, the UE 106 may additionally or alternatively be configured to communicate using one or more global navigation satellite systems (GNSS) (e.g., GPS or GLONASS), one or more mobile television broadcast standards (e.g., ATSC-M / H), and / or any other wireless communication protocols. Other combinations of wireless communication standards (including more than two wireless communication standards) are also possible.

[0059] like Figure 2 As illustrated, in one or more embodiments, the UE 106 may be a device with cellular communication capabilities, such as a mobile phone, handheld device, computer, laptop, tablet, smart watch or other wearable device, or virtually any type of wireless device.

[0060] The UE 106 may include a processor (processing element) configured to execute program instructions stored in a memory. The UE 106 may perform any of the method aspects described herein by executing such stored instructions. Alternatively or in addition, the UE 106 may include a programmable hardware element, such as an FPGA (field programmable gate array), an integrated circuit, and / or any of various other possible hardware components configured to perform (e.g., individually or in combination) any of the method aspects described herein or any portion of any of the method aspects described herein.

[0061] The UE 106 may include one or more antennas for communicating using one or more wireless communication protocols or technologies. In some aspects, the UE 106 may be configured to communicate using, for example, NR or LTE using at least some shared radio components. As an additional possibility, the UE 106 may be configured to communicate using CDMA2000 (1xRTT / 1xEV-DO / HRPD / eHRPD) or LTE using a single shared radio component and / or GSM or LTE using a single shared radio component. The shared radio component may be coupled to a single antenna, or may be coupled to multiple antennas (e.g., for a multiple-input, multiple-output (MIMO) configuration) for performing wireless communications. Generally speaking, the radio component may include any combination of a baseband processor, analog RF signal processing circuitry (e.g., including filters, mixers, oscillators, amplifiers, etc.), or digital processing circuitry (e.g., for digital modulation and other digital processing). Similarly, the radio component may implement one or more receive chains and transmit chains using the aforementioned hardware. For example, UE 106 may share one or more portions of a receive chain and / or a transmit chain between multiple wireless communication technologies, such as those discussed above.

[0062] In some aspects, the UE 106 may include a separate transmit chain and / or receive chain (e.g., including separate antennas and other radio components) for each wireless communication protocol with which it is configured to communicate. As another possibility, the UE 106 may include one or more radio components shared between multiple wireless communication protocols, and one or more radio components used uniquely by a single wireless communication protocol. For example, the UE 106 may include a shared radio component for communicating using either LTE or 5G NR (or either LTE or 1xRTT, or either LTE or GSM, among other possibilities), and separate radio components for communicating using each of Wi-Fi and Bluetooth. Other configurations are also possible.

[0063] In some aspects, a downlink resource grid may be used for downlink transmissions from any of the base stations 102 to the UE 106, while uplink transmissions may utilize similar techniques. The grid may be a time-frequency grid, referred to as a resource grid or a time-frequency resource grid, which is the physical resource in the downlink in each time slot. For orthogonal frequency division multiplexing (OFDM) systems, such a time-frequency plane representation is conventional practice, which makes radio resource selection intuitive. Each column and each row of the resource grid corresponds to an OFDM symbol and an OFDM subcarrier, respectively. The duration of the resource grid in the time domain corresponds to a time slot in the radio frame. The smallest time-frequency unit in the resource grid is represented as a resource element. Each resource grid may include multiple resource blocks, which describe the mapping of specific physical channels to resource elements. Each resource block includes a collection of resource elements. Such resource blocks are used to transport several different physical downlink channels.

[0064] The physical downlink shared channel (PDSCH) can carry user data and higher layer signaling to the UE 106. The physical downlink control channel (PDCCH) can carry information about, among other things, the transport format and resource allocation associated with the PDSCH channel. It can also inform the UE 106 of the transport format, resource allocation, and HARQ (Hybrid Automatic Repeat Request) information associated with the uplink shared channel. Typically, downlink scheduling (assignment of control and shared channel resource blocks to UEs 102 within a cell) can be performed at any of the base stations 102 based on channel quality information fed back from any of the UEs 106. Downlink resource allocation information can be transmitted on the PDCCH for (e.g., assigned to) each of the UEs.

[0065] PDCCH can use control channel elements (CCE) to convey control information. Before being mapped to resource elements, the PDCCH complex-valued symbols can first be organized into quadruples, which can then be arranged using a sub-block interleaver for rate matching. One or more of these CCEs can be used to send each PDCCH, where each CCE can correspond to four sets of nine physical resource elements, called resource element groups (REGs). Four quadrature phase shift keying (QPSK) symbols can be mapped to each REG. Depending on the size of the downlink control information (DCI) and the channel conditions, one or more CCEs can be used to send PDCCH. There may be four or more different PDCCH formats defined in LTE with different numbers of CCEs (e.g., aggregation levels, L=1, 2, 4, or 8).

[0066] Example Communication Device

[0067] Figure 3 1 illustrates an exemplary simplified block diagram of a communication device 106 according to some aspects. Note that Figure 3 The block diagram of the communication device is only one example of a possible communication device. According to various aspects, the communication device 106 can be, among other devices, a UE device or terminal, a mobile device or mobile station, a wireless device or wireless station, a desktop computer or computing device, a mobile computing device (e.g., a laptop, notebook or portable computing device), a tablet computer and / or a combination of devices. As shown, the communication device 106 may include a component set configured to perform core functions. For example, the component set may be implemented as a system on a chip (SOC), which may include parts for various purposes. Alternatively, the component set may be implemented as individual components or groups of components for various purposes. The component set may be coupled (e.g., communicatively; directly or indirectly) to various other circuits of the communication device 106.

[0068] For example, the communication device 106 may include various types of memory (e.g., including NAND flash memory 310), input / output interfaces such as a connector I / F 320 (e.g., for connecting to a computer system; a docking station; a charging station; input devices such as a microphone, a camera, a keyboard; output devices such as a speaker; etc.), a display 360 that may be integrated with the communication device 106 or external to it, and wireless communication circuitry 330 (e.g., for LTE, LTE-A, NR, UMTS, GSM, CDMA2000, Bluetooth, Wi-Fi, NFC, GPS, etc.). In some aspects, the communication device 106 may include wired communication circuitry (not shown), such as a network interface card (e.g., for Ethernet connectivity).

[0069] Wireless communication circuitry 330 may be (e.g., communicatively; directly or indirectly) coupled to one or more antennas, such as antenna 335 as shown. Wireless communication circuitry 330 may include cellular communication circuitry and / or short- to medium-range wireless communication circuitry, and may include multiple receive chains and / or multiple transmit chains for receiving and / or transmitting multiple spatial streams, such as in a MIMO configuration.

[0070] In some aspects, as further described below, the cellular communication circuitry 330 may include one or more receive chains (including and / or coupled to (e.g., communicatively; directly or indirectly) dedicated processors and / or radios) for multiple radio access technologies (RATs) (e.g., a first receive chain for LTE and a second receive chain for 5G NR). Furthermore, in some aspects, the cellular communication circuitry 330 may include a single transmit chain that can switch between radios dedicated to specific RATs. For example, a first radio may be dedicated to a first RAT (e.g., LTE) and may communicate with a dedicated receive chain and a transmit chain shared with a second radio. A second radio may be dedicated to a second RAT (e.g., 5G NR) and may communicate with a dedicated receive chain and a shared transmit chain. In some aspects, the second RAT may operate at millimeter wave frequencies. Because millimeter wave systems operate at higher frequencies than typical frequencies in LTE systems, signals within the millimeter wave frequency range can be significantly attenuated by environmental factors. To help address this attenuation, millimeter wave systems typically utilize beamforming and include more antennas than LTE systems. These antennas can be organized into antenna arrays or panels consisting of individual antenna elements.These antenna arrays can be coupled to a radio link.

[0071] The communication device 106 may also include and / or be configured for use with one or more user interface elements.

[0072] The communication device 106 may also include one or more smart cards 345 , such as one or more Universal Integrated Circuit Cards (UICCs) 345 , that include Subscriber Identity Module (SIM) functionality.

[0073] As shown, SOC 300 may include a processor 302 that can execute program instructions for communication device 106 and a display circuit 304 that can perform graphics processing and provide display signals to display 360. Processor 302 may also be coupled to a memory management unit (MMU) 340 that can be configured to receive addresses from processor 302 and translate these addresses into locations in memory (e.g., memory 306, read-only memory (ROM) 350, NAND flash memory 310); and / or to other circuits or devices such as display circuit 304, wireless communication circuit 330, connector I / F 320, and / or display 360. MMU 340 may be configured to perform memory protection and page table translation or setup. In some aspects, MMU 340 may be included as part of processor 302.

[0074] As described above, the communication device 106 can be configured to communicate using wireless and / or wired communication circuits. As described herein, the communication device 106 may include hardware and software components for implementing any of the various features and techniques described herein. The processor 302 of the communication device 106 can be configured to implement part or all of the features described herein (e.g., by executing program instructions stored on a memory medium). Alternatively (or in addition), the processor 302 can be configured as a programmable hardware element, such as a field programmable gate array (FPGA) or an application specific integrated circuit (ASIC). Alternatively (or in addition), in combination with one or more of the other components 300, 304, 306, 310, 320, 330, 340, 345, 350, 360, the processor 302 of the communication device 106 can be configured to implement part or all of the features described herein.

[0075] Furthermore, as described herein, processor 302 may include one or more processing elements. Thus, processor 302 may include one or more integrated circuits (ICs) configured to perform the functions of processor 302. Furthermore, each integrated circuit may include circuits (e.g., a first circuit and a second circuit, etc.) configured to perform the functions of processor 302.

[0076] Furthermore, as described herein, wireless communication circuitry 330 may include one or more processing elements. In other words, one or more processing elements may be included in wireless communication circuitry 330. Thus, wireless communication circuitry 330 may include one or more integrated circuits (ICs) configured to perform the functions of wireless communication circuitry 330. Furthermore, each integrated circuit may include circuitry (e.g., a first circuit and a second circuit, etc.) configured to perform the functions of wireless communication circuitry 330.

[0077] Example base station

[0078] Figure 4 1 illustrates an exemplary block diagram of a base station 102 according to some aspects. Figure 4 The base stations of are non-limiting examples of possible base stations. As shown, base station 102 may include a processor 404 that may execute program instructions for base station 102. Processor 404 may also be coupled to a memory management unit (MMU) 440 that may be configured to receive addresses from processor 404 and translate those addresses into locations in memory (e.g., memory 460 and read-only memory (ROM) 450); or to other circuits or devices.

[0079] The base station 102 may include at least one network port 470. The network port 470 may be configured to couple to a telephone network and provide access to the telephone network as described above. Figure 1Multiple devices (such as UE device 106) of the telephone network described in.

[0080] The network port 470 (or an additional network port) may also or alternatively be configured to couple to a cellular network, such as a core network of a cellular service provider. The core network may provide mobility-related services and / or other services to a plurality of devices, such as the UE device 106. In some cases, the network port 470 may be coupled to a telephone network via the core network, and / or the core network may provide a telephone network (e.g., in addition to other UE devices served by the cellular service provider).

[0081] In some aspects, base station 102 can be a next-generation base station (e.g., a 5G New Radio (5GNR) base station or "gNB"). In such aspects, base station 102 can be connected to a legacy evolved packet core (EPC) network and / or to an NR core (NRC) / 5G core (5GC) network. Furthermore, base station 102 can be considered a 5G NR cell and can include one or more transition and reception points (TRPs). Furthermore, UEs capable of operating in accordance with 5G NR can be connected to one or more TRPs within one or more gNBs.

[0082] Base station 102 may include at least one antenna 434, and may include multiple antennas. At least one antenna 434 may be configured to operate as a wireless transceiver and may be further configured to communicate with UE device 106 via radio 430. Antenna 434 communicates with radio 430 via communication chain 432. Communication chain 432 may be a receive chain, a transmit chain, or both. Radio 430 may be configured to communicate via various wireless communication standards, including 5G NR, LTE, LTE-A, GSM, UMTS, CDMA2000, and Wi-Fi, among others.

[0083] The base station 102 may be configured to communicate wirelessly using multiple wireless communication standards. In some instances, the base station 102 may include multiple radio components that enable the base station 102 to communicate according to multiple wireless communication technologies. For example, as one possibility, the base station 102 may include an LTE radio component for communicating according to LTE and a 5G NR radio component for communicating according to 5G NR. In this case, the base station 102 may be capable of operating as both an LTE base station and a 5G NR base station. When the base station 102 supports millimeter waves, the 5G NR radio component may be coupled to one or more millimeter wave antenna arrays or panels. As another possibility, the base station 102 may include a multimode radio component capable of communicating according to any of multiple wireless communication technologies (e.g., 5G NR and LTE, 5G NR and Wi-Fi, LTE and Wi-Fi, LTE and UMTS, LTE and CDMA2000, UMTS and GSM, etc.).

[0084] In addition, BS 102 may include hardware and software components for implementing or supporting the specific implementation of the features described herein. The processor 404 of base station 102 may be configured to implement or support a specific implementation of part or all of the methods described herein (e.g., by executing program instructions stored on a memory medium). Alternatively, the processor 404 may be configured as a programmable hardware element (such as a field programmable gate array (FPGA)), or an application specific integrated circuit (ASIC), or a combination thereof. Alternatively (or in addition), in combination with one or more of the other components 430, 432, 434, 440, 450, 460, 470, the processor 404 of BS 102 may be configured to implement or support implementation of part or all of the features described herein.

[0085] Furthermore, as described herein, processor 404 may include one or more processing elements. Thus, processor 404 may include one or more integrated circuits (ICs) configured to perform the functions of processor 404. Furthermore, each integrated circuit may include circuits (e.g., a first circuit and a second circuit, etc.) configured to perform the functions of processor 404.

[0086] Furthermore, as described herein, radio 430 may include one or more processing elements. Thus, radio 430 may include one or more integrated circuits (ICs) configured to perform the functions of radio 430. Furthermore, each integrated circuit may include circuitry (e.g., a first circuit and a second circuit, etc.) configured to perform the functions of radio 430.

[0087] Buffer Status Report

[0088] Now go to Figure 5 , illustrates a diagram 500 of a method for exchanging a buffer status report (BSR) 515 and an uplink grant 520 between a UE 505 and a base station (i.e., a gNodeB 510), according to a detailed description of some aspects. At a high level, a UE 505 may transmit a buffer status report (BSR) 515 to the base station 510 to indicate the amount of uplink data the UE must send. The BSR 515 may be sent as a medium access control (MAC) control element (CE) on a physical uplink shared channel (PUSCH). The BSR 515 may be associated with a logical channel group (LCG) having one or more logical channels (LCHs). Upon receiving the BSR 515, the base station 510 may determine an appropriate amount of uplink resources for the UE. The base station 510 may then send an uplink grant 520 to the UE 505. The UE 505 may then use the UL grant for subsequent uplink transmissions 525.

[0089] In various embodiments, the UE may send a regular BSR, a periodic BSR, or a padding BSR. A regular BSR may be triggered when new uplink data for an LCH in an LCG becomes available in the MAC buffer and the LCH has a higher priority than any other LCH with buffered data; or when no other LCH has buffered data. A regular BSR may also be triggered when the retransmit BSR timer (i.e., retxBSR-Timer) expires and the LCH includes buffered data to be sent. The retransmit BSR timer may be used to avoid deadlock situations that may occur when the base station fails to receive the BSR, but the UE believes that the BSR was sent successfully. Thus, the retransmit BSR timer provides a finite period of time that the UE will wait for an uplink grant before retransmitting the BSR. The retransmit BSR timer is started when the BSR is multiplexed into the MAC PDU.

[0090] A periodic BSR may be triggered when a periodic BSR timer (i.e., periodicBSR-Timer) expires. A padding BSR may be triggered if the allocated uplink resources have a number of padding bits that equals or exceeds the size of the BSR. Thus, a padding BSR provides an opportunity to utilize unused uplink capacity.

[0091] Existing networks may include multiple BSR formats, including short BSR format (fixed size), extended short BSR format (fixed size), long BSR format (variable size), extended long BSR format (variable size), short truncated BSR format (fixed size), long truncated BSR format (variable size), and extended long truncated BSR format (variable size). The selection between these formats in existing networks is fixed in clause 5.4.5 of 3GPP TS 38.321. The selection may be based on the number of LCGs with data available for transmission, whether the MAC entity has a configured logical channel group IAB extension (i.e., logicalChannelGroup-IAB-Ext), and, for padding BSRs, the number of available padding bits compared to the size of the various formats.

[0092] Service types are evolving to accommodate new use cases in developing cellular networks. For example, as described above, efforts are underway to improve RAN operations to support services with characteristics associated with extended reality (XR) services, providing, for example, high throughput, low latency, and high reliability. Various enhancements to SR and BSR operations can be used to improve the capacity and latency of data transmission in XR application use cases. While some embodiments are described with reference to XR services, other embodiments may apply similar concepts to other types of services.

[0093] According to some aspects, the BSR (or other MAC CEs that may be used in a given implementation) can be enhanced for XR use cases by including additional types of information. Existing BSRs only provide information about the size of the buffer. To facilitate delay-aware scheduling of XR traffic with latency constraints, the BSR can also include information related to the delay status of the buffered data. For example, the BSR may include an indication of how long data has been queued or the amount of time remaining until a delivery deadline.

[0094] Protocol Data Unit (PDU) aggregation and Quality of Service (QoS) processing for delay-sensitive applications

[0095] Now go to Figure 6 , according to some aspects, an example 600 of an exemplary PDU set 602 containing different numbers of data packets 604 is illustrated. For example, PDU set #1 (6021) may contain packets 6041, 6042, and 6043, and PDU set #2 (6022) may contain packets 6044 and 6045. XR services are an example of wireless data that can be operated based on PDU sets. Figure 6As illustrated, a PDU set may correspond to an application data unit, which may include multiple packets / PDUs. A user plane function (UPF) may identify a PDU set based on a PDU set sequence number (SN), a start / end PDU of the PDU set, a PDU SN within the PDU set, or the number of PDUs within the PDU set.

[0096] A Quality of Service (QoS) flow can be identified using a QoS flow ID, and each PDU set within a QoS flow can be identified using a PDU set SN. Each QoS flow can be used to transmit one or more PDU sets. The UPF can also identify information related to the PDU set, such as PDU set importance or PDU set dependency. The UPF can provide information related to the PDU set to the RAN. QoS parameters for PDU set-based QoS processing may include a PDU set delay budget (PSDB), a PDU set error rate (PSER), whether to discard a PDU set if the PSDB is exceeded, whether all PDUs are required for application layer use of the PDU set, and PDU set priority. The network can configure the UE to map a first QoS flow (e.g., QoS flow 1) to a first radio bearer (e.g., radio bearer 1), and then map a second QoS flow (e.g., QoS flow 2) to a second radio bearer (e.g., radio bearer 2), and then the network can configure different radio-related configurations and / or parameterizations for different radio bearers (e.g., radio bearer 1 and radio bearer 2). The characteristics of the buffered PDU set (eg, the importance level of the PDU set) may also be indicated in the BSR (or other form of MAC CE as may be used in a given implementation).

[0097] In XR applications (or other time-sensitive applications), there is a chance that some packets of a PDU set may be dropped even before they are sent, for example, if the PSDB is exceeded and / or if the application layer does not need all PDUs to use the PDU set, etc. Other scenarios where proactive packet drops may occur include: (1) if all packets in a PDU set must be successfully delivered for the application layer, then all packets in the PDU set do not have to be sent if one or more of all packets in the PDU set have failed; (2) if at least one critical / essential PDU set has failed, then the remaining packets in the same PDU set do not need to be sent; (3) if it is sufficient for the application layer to successfully receive only a portion of the PDU set, then once the required portion of the PDU set has been successfully delivered, the transmitter may drop the remaining packets in the PDU set to save power / resources; (4) if there are interdependencies between different PDU sets, then the transmitter may determine to drop or continue sending the PDU set based on the status of another interdependent PDU set; or (5) the transmitter may proactively drop some packets in order to relieve traffic congestion.

[0098] When a packet drop decision is made, regardless of the reason for the packet drop, packets from one or more PDU sets still queued in the LCH buffer may be cleared. Therefore, when a packet drop occurs, the UL buffer status will experience a changed buffer condition (e.g., the buffer may become less full or even empty). It is important for the gNB to be aware of such changes in buffer conditions (i.e., due to packet drops) as quickly as possible. Otherwise, the gNB may allocate radio resources based on outdated knowledge of the buffer status (i.e., the buffer status before the most recent packet drop event).

[0099] On the other hand, many services in XR applications are delay-sensitive and need to be delivered within a certain time budget (e.g., PSDB) in order to be useful to the application. To enable delay-aware scheduling, it has been proposed that buffer status reporting should be enhanced to include additional information, such as queuing delay time and / or the remaining time until the delivery deadline. This information would allow the gNB to allocate uplink resources in a more timely manner. According to such proposals, new triggering events for BSRs (or other MAC CEs) related to delay information (such as queuing time) could be introduced. For example, a BSR including queuing delay information could be triggered when buffered data has been waiting in the buffer for a certain amount of time. This type of BSR should be transmitted very urgently so that the gNB can be aware that the buffered data is time-critical.

[0100] A Scheduling Request (SR) can be triggered and become pending by a packet arriving on a logical channel (LCH), where the UE can transmit an SR to obtain a Physical Uplink Shared Channel (PUSCH) allocation in order to transmit a BSR. Therefore, a SR triggered by a BSR is currently only canceled when the BSR containing the corresponding buffer is included in the Medium Access Control (MAC) Protocol Data Unit (PDU) for transmission. Otherwise, it is considered "pending" and the UE will continue to signal these SRs in the corresponding PUCCH. Once an SR is signaled on the PUCCH, the UE should start (or restart) the sr-ProhibitTimer (wherein, if the sr-ProhibitTimer is running, the UE is not allowed to transmit an SR). Therefore, when an SR is canceled (e.g., when a BSR is multiplexed into a MAC PDU), the UE should also stop running the sr-ProhibitTimer. When an SR is signaled, the UE should increment the SR counter. Then, when the SR counter reaches sr-TransMax, the UE may no longer be able to signal an SR. Some example solutions for improving the handling of SRs when certain types of special events occur (such as packet drops or long packet queuing delays) are described below. However, it should be understood that the solutions described herein are not intended to be limited to these types of special events, and they may also be employed in response to the occurrence of other types of special events (e.g., when the UE receives specific types of downlink data, control signals, or other types of messages), as may be desired in a given implementation.

[0101] Example solution for improving handling of SR in the event of packet drops or long packet queuing delays

[0102] Whenever a packet drop event occurs, there may be two potential expected UE behaviors: (1) for the UE to avoid any unnecessary SR signaling; or (2) to transmit a new BSR to update the base station about the buffer status. Regarding potential UE behavior in response to packet drop (1), if there is already a pending SR, the UE may want to cancel the SR if the data in the buffer is no longer available due to the packet drop. However, if there is no pending SR, no action from the UE may be required. Regarding potential UE behavior in response to packet drop (2), if there is already a pending SR, the UE may want to signal the pending SR as soon as possible in order to transmit a BSR to update the base station about the buffer status. However, if there is no pending SR, the UE may trigger an SR to obtain UL resources for the BSR.

[0103] Whenever a BSR is triggered by a long queuing delay, potential expected UE behavior may include the following: if there is already a pending SR, the UE may want to signal the pending SR as soon as possible in order to transmit the BSR and provide queuing delay time information; however, if there is no pending SR, the UE may trigger an SR to obtain UL resources for the BSR. The UE may also preferably want to transmit the SR as soon as possible. Therefore, this document describes various solutions for handling SRs when the BSR is triggered by packet drops or long queuing times.

[0104] Packet discard

[0105] When a BSR is triggered due to an event related to packet drop, the UE may check whether there is any pending SR previously triggered by at least one LCH related to the triggered BSR. If so, the UE may determine to perform one of the following actions: (1) cancel the pending SR and stop the sr-ProhibitTimer if it is running; (2) trigger another SR associated with a different SR configuration; (3) if the sr-ProhibitTimer is running, keep the pending SR but stop the sr-ProhibitTimer; (4) keep the pending SR but switch the PUCCH configuration associated with the pending SR; or (5) reset the value of the SR counter (e.g., to zero).

[0106] Conversely, if there is no pending SR, the UE may determine to perform one of the following actions: (1) trigger an SR associated with a default or special SR configuration (e.g., the relevant LCH may be associated with at least two SR configurations, one default configuration for the LCH, and one special SR configuration for the case where the queuing delay has exceeded a threshold); (2) trigger an SR and use an alternative sr-ProhibitTimer (e.g., a timer with a value shorter than the default); or (3) trigger an SR and signal the SR using a different PUCCH configuration.

[0107] The behavior the UE chooses to take in any given scenario may depend on one or more of the following factors: (1) pre-configuration by the gNB; (2) UE specific implementation; or (3) the buffer status after the packet drop. For example, if the buffer is emptied after the packet drop, the UE may simply cancel the pending SR. Alternatively, if some data is still in the buffer after the packet drop, the UE may keep the pending SR but stop running the sr-ProhibitTimer so that the UE can signal an SR again more quickly.

[0108] Long queue delays

[0109] When a BSR (or other type of MAC CE) for delay information is triggered due to an event related to a long queue time of buffered data and / or the amount of time remaining until a delivery deadline, the UE may check whether there is any pending SR previously triggered by at least one LCH associated with the triggered BSR (or MAC CE element). If so, the UE may determine to perform one of the following actions: (1) cancel the pending SR and, if the sr-ProhibitTimer is running, stop the sr-ProhibitTimer; (2) trigger another SR associated with a different SR configuration; (3) if the sr-ProhibitTimer is running, keep the pending SR but stop the sr-ProhibitTimer; (4) keep the pending SR but switch the PUCCH configuration associated with the pending SR; or (5) reset the value of the SR counter (e.g., to zero).

[0110] Conversely, if there is no pending SR, the UE may determine to perform one of the following actions: (1) trigger an SR associated with a default or special SR configuration (e.g., the relevant LCH may be associated with at least two SR configurations, one default configuration, and one special SR configuration for situations where the queuing delay is too long); (2) trigger an SR and use an alternative sr-ProhibitTimer (e.g., a timer with a shorter value than the default); (3) trigger an SR and signal the SR using a different PUCCH configuration. The specific action the UE determines to take may depend on one or more of: pre-configuration by the gNB; or UE specific implementation.

[0111] Now go to Figure 7 , illustrates a flow chart detailing a method 700 for handling a scheduling request (SR) when a BSR is triggered by a specific event, such as a packet drop or a long packet queuing delay, according to some aspects. As outlined above, the method 700 may begin at block 702 when a BSR is triggered. Next, at block 704, the UE may evaluate whether the BSR was triggered by a packet queuing delay-related event or a packet drop event. If the BSR has not been triggered by one of these two types of events (i.e., "No" at block 704), the method 700 may proceed to block 706, where the UE may trigger an SR using a default SR configuration and procedure.

[0112] Conversely, if a BSR has been triggered by one of these two types of events (i.e., "yes" at block 704), method 700 may proceed to block 708, where the UE may perform a second check to determine whether a pending SR already exists for the LCH associated with the triggered BSR. If no pending SR exists for the LCH (i.e., "no" at block 708), method 700 may proceed to block 710, where the UE may trigger an SR using an alternative (i.e., non-default) SR configuration and procedure (such as the various options outlined in the above sections). Conversely, if a pending SR already exists for the LCH (i.e., "yes" at block 708), method 700 may proceed to block 712, where the UE may stop the sr-ProhibitTimer of the pending SR (if it is still running) and / or change one or more parameters of the pending SR (e.g., change its PUCCH resources).

[0113] In some embodiments, at block 708, the UE may also first determine whether there is an UL-SCH available for BSR transmission, and then the UE should only trigger a new SR if no such UL-SCH is available. In still other embodiments, at block 712, the MAC may instruct the physical layer (PHY) to directly signal the SR.

[0114] Now go to Figure 8 , illustrates diagrams 800 / 820 / 840 of exemplary SR configurations for handling BSRs (or other MAC CEs) triggered by various types of events, such as packet drops or long packet queuing delays, according to a detailed description of some aspects. As shown in diagram 800, a particular logical channel LCH 802 may be associated with multiple SR configurations, e.g., SR configuration #1 (804) and SR configuration #2 (806). These SR configurations may be associated with different types of triggering events for a BSR or other MAC CE. For example, SR configuration #1 (804) may be used for BSRs triggered by normal events that are not related to queuing delays or packet drops, and SR configuration #2 (806) (which may differ from SR configuration #1 in one or more aspects) may be used for BSRs triggered by events related to queuing delays (e.g., when the queuing delay of buffered data has exceeded a threshold, or when the remaining time of a delivery deadline is less than a threshold) or packet drops. In diagram 800, SR configuration #1 (804) is associated with a first PUCCH resource configuration #1 (808), and SR configuration #2 (806) is associated with a second (e.g., different) PUCCH resource configuration #2 (810). The two SR configurations may also have other different SR parameters, such as different sr-ProhibitTimers.

[0115] Turning to diagram 820, an embodiment is illustrated in which a first SR prohibit timer #1 (822) and a second (e.g., different or shorter) SR prohibit timer #2 (824) may each be associated with SR configuration #1 (804), for example, at different times and / or in response to different events or conditions detected at the UE. For example, SR prohibit timer #1 (822) may be used for BSRs triggered by normal events not related to queuing delay or packet drop, and SR prohibit timer #2 (824) may be used for BSRs triggered by events related to queuing delay (e.g., when the queuing delay of buffered data has exceeded a threshold, or when the remaining time of a delivery deadline is less than a threshold) or packet drop.

[0116] Finally, turning to diagram 840, an embodiment is illustrated in which a first PUCCH resource configuration #1 (808) and a second (e.g., different) PUCCH resource configuration #2 (810) may each be associated with SR configuration #1 (804), e.g., at different times and / or in response to different events or conditions detected at the UE. For example, PUCCH resource configuration #1 (808) may be used for a BSR triggered by a normal event not related to queuing delay or packet drop, and PUCCH resource configuration #2 (810) may be used for a BSR triggered by an event related to queuing delay (e.g., when the queuing delay of buffered data has exceeded a threshold, or when the remaining time of a delivery deadline is less than a threshold) or packet drop.

[0117] Exemplary Methods

[0118] Now go to Figure 9 , illustrates a flowchart 900 detailing a method for handling a BSR when a BSR is triggered by a packet drop or a long packet queuing delay, according to some aspects. First, at block 902, a UE practicing the method of 900 may detect a condition corresponding to a first buffer condition (e.g., a packet queuing delay condition or a packet drop condition) of a buffer of the UE. Next, at block 904, the UE may determine a first logical channel (LCH) associated with the first buffer condition. Next, at block 906, the UE may determine whether a first scheduling request (SR) is already pending for the first LCH.

[0119] Next, at box 908, in response to determining that there is a first SR pending for the first LCH (i.e., the response at box 906 is "yes"), the UE may modify at least one parameter of the first SR pending for the first LCH (e.g., stop the inhibit timer of the first SR, cancel the first SR, trigger a new SR with an SR configuration different from the first SR, modify the physical uplink control channel (PUCCH) resource configuration used to signal the first SR, or reset the value of the counter for the first SR, etc.).

[0120] Alternatively, at box 910, in response to determining that there is no first SR pending for the first LCH (i.e., the response at box 906 is "No"), the UE may trigger a second SR for the first LCH, wherein the second SR has at least one parameter modified relative to the parameters used for the default SR configuration corresponding to the first LCH (e.g., a different SR configuration, a different SR prohibit timer, or a different PUCCH resource configuration, etc.).

[0121] Next, method 900 may end, or the UE may simply return to block 902 and continue detecting if and when the first buffer condition is again detected at the UE device, thereby re-performing method 900 until the UE is no longer required to monitor its buffer condition.

[0122] In some embodiments, the first buffer condition detected in block 902 may trigger a first buffer status report (BSR). In some such embodiments, the buffer includes traffic for a plurality of LCHs of one or more logical channel groups (LCGs), and the first buffer condition is associated with one or more of the plurality of LCHs (or it may be associated with any of the plurality of LCHs). In some embodiments, the first BSR reports information only for the first LCH, while in other embodiments, the first BSR reports information for each LCH in the LCG associated with the first LCH.

[0123] Additional Notes

[0124] The use of the conjunction "and / or" is intended to represent all possible alternatives of the conjunction "and" and the conjunction "or." For example, the sentence "the configuration of A and / or B" includes the meaning of the sentence "the configuration of A and B" and "the configuration of A or B."

[0125] It is understood that the use of personally identifiable information should be subject to privacy policies and practices that are generally recognized to meet or exceed industry or government requirements for maintaining user privacy. Specifically, personally identifiable information data should be managed and processed to minimize the risk of unintentional or unauthorized access or use, and the nature of authorized use should be clearly stated to users.

[0126] Aspects of the present disclosure can be implemented in any of a variety of forms. For example, some aspects can be implemented as computer-implemented methods, computer-readable storage media, or computer systems. Other aspects can be implemented using one or more custom-designed hardware devices such as ASICs. Other aspects can be implemented using one or more programmable hardware elements such as FPGAs.

[0127] In some aspects, a non-transitory computer-readable storage medium may be configured such that it stores program instructions and / or data, where the program instructions, when executed by a computer system, cause the computer system to perform a method (e.g., any of the method aspects described herein, or any combination of the method aspects described herein, or any subset of any of the method aspects described herein, or any combination of such subsets).

[0128] In some aspects, a device (e.g., UE 106, BS 102) may be configured to include a processor (or a group of processors) and a memory medium, wherein the memory medium stores program instructions, wherein the processor is configured to read and execute the program instructions from the memory medium, wherein the program instructions are executable to implement any of the various method aspects described herein (or any combination of the method aspects described herein, or any subset of any method aspects of the method aspects described herein, or any combination of such subsets). The device may be implemented in any of various forms.

[0129] Although the above aspects have been described in considerable detail, numerous variations and modifications will become apparent to those skilled in the art once the above disclosure is fully appreciated. It is intended that the following claims be interpreted to encompass all such variations and modifications.

Claims

1. A method of operating a user equipment (UE), the method comprising: detecting a condition of a buffer of the UE corresponding to a first buffer condition; determining a first logical channel (LCH) associated with the first buffer condition; determining whether there is a first scheduling request (SR) pending for the first LCH; In response to determining that there is a first SR pending for the first LCH: modifying at least one parameter of the first SR pending for the first LCH; and In response to determining that there is no first SR pending for the first LCH: A second SR for the first LCH is triggered, wherein the second SR has at least one parameter modified relative to a parameter of a default SR configuration corresponding to the first LCH.

2. The method of claim 1, wherein the first buffer condition triggers a first buffer status report (BSR) or a first medium access control (MAC) control element (CE).

3. The method according to claim 1, further comprising: Determining the first buffer condition includes a packet queuing delay condition or a packet discard condition.

4. The method of claim 3 , wherein the first buffer condition is related to packet queuing delay, and wherein the method further comprises: Transmitting packet queuing delay time information to the base station.

5. The method of claim 3 , wherein the first buffer condition is related to packet queuing delay, and wherein the first buffer condition indicates at least one of the following conditions: (a) the queuing delay of buffered data has exceeded a threshold; or (b) The amount of time remaining until the delivery deadline of the buffered data is less than a threshold value.

6. The method of claim 5, wherein the delivery deadline for the buffered data is derived based at least in part on a delay budget associated with one or more packets within the buffered data.

7. The method of claim 1 , wherein modifying at least one parameter of the first SR pending for the first LCH comprises at least one of: (a) stopping the inhibit timer of the first SR; (b) canceling the first SR; (c) triggering a new SR having a different SR configuration from the first SR; (d) modifying a Physical Uplink Control Channel (PUCCH) configuration used to signal the first SR; or (e) Resetting the value of the counter for the first SR.

8. The method according to claim 7, wherein: (c) triggering a new SR having an SR configuration different from that of the first SR further includes: A new SR is triggered with an inhibit timer shorter than the inhibit timer of the first SR.

9. The method of claim 1 , wherein modifying at least one parameter of the first SR pending for the first LCH further comprises: The first SR is signaled at the next available opportunity, whether or not the SR inhibit timer for the first SR is still running.

10. The method of claim 1, wherein a medium access control (MAC) layer instructs the UE to use a physical layer (PHY) to directly signal the first SR to a base station.

11. The method of claim 1 , wherein the second SR having at least one parameter modified relative to a parameter for a default SR configuration comprises at least one of: (a) the second SR has an SR configuration different from the default SR configuration; (b) the second SR has an SR inhibit timer configuration that is different from the default SR configuration; or (c) The second SR uses a PUCCH configuration different from the default SR configuration.

12. The method according to claim 11, wherein: (b) the second SR having an SR prohibit timer configuration different from the default SR configuration further includes: The second SR has an SR prohibit timer configuration that is shorter than an SR prohibit timer configuration of the default SR configuration.

13. The method according to claim 2, wherein triggering the second SR further comprises: The second SR is triggered to obtain uplink (UL) resource allocation for the first BSR.

14. The method according to claim 1, wherein triggering the second SR further comprises: The second SR is triggered in response to determining that there is no uplink shared channel (UL-SCH) available for use by the UE.

15. The method of claim 1 , wherein the first buffer condition is based on at least one of the following: (a) determining whether the application needs to buffer all PDUs in the protocol data unit (PDU) set; (b) a comparison of the time remaining until the delivery deadline of the buffered data with a predetermined threshold; (c) comparison of the queuing time of the buffered data with a predetermined threshold; (d) comparison of the amount of buffered data with a predetermined threshold; (e) the importance or priority associated with the buffered PDU set; (f) whether the packet drop is configured for a buffered PDU set or a radio bearer corresponding to the buffered PDU set; (g) whether a packet discard event occurs; (h) comparison of the amount of discarded data with a predetermined threshold; (i) a comparison of the amount of buffered data remaining after a packet drop event has occurred with a predetermined threshold; or (j) Determine whether the amount of buffered data remaining after the packet drop event is zero.

16. The method of claim 1 , wherein the buffer comprises traffic for a plurality of LCHs for one or more logical channel groups (LCGs), and wherein the first buffer condition is associated with one or more of the plurality of LCHs or with any of the plurality of LCHs.

17. The method according to claim 2, further comprising: Send the first BSR to the base station.

18. The method according to claim 17, wherein: The first BSR only reports information for the first LCH.

19. The method of claim 17, wherein: The first BSR reports information for each LCH in a logical channel group (LCG) associated with the first LCH.

20. A user equipment (UE) device, the user equipment (UE) device comprising: Receiver; transmitter; and a processor configured to perform any action or combination of actions described in any of the methods according to claims 1 to 19.

21. A non-transitory computer readable medium storing instructions which, when executed, cause any action or combination of actions described in any of the methods of claims 1 to 19 to be performed.

22. A baseband processor configured to cause a user equipment (UE) to perform any action or combination of actions described in any of the methods according to claims 1 to 19.

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