Indicating protocol data unit (PDU) importance information

Abstract

NOT VISIBLE DUE TO STATUS OF PATENT

Description

[0001] INDICATING PROTOCOL DATA UNIT (PDU) IMPORTANCE INFORMATION

[0002] TECHNICAL FIELD

[0003] The present disclosure relates generally to wireless communication networks, and more specifically to techniques for wireless devices to report about importance information associated with buffered data for applications, especially for applications needing guaranteed low latency such as extended reality (XR) and cloud gaming.

[0004] BACKGROUND

[0005] Currently the fifth generation (5G) of cellular is being standardized within the Third- Generation Partnership Project (3GPP). NR is developed for maximum flexibility to support multiple and substantially different use cases. These include enhanced mobile broadband (eMBB), machine type communications (MTC), ultra-reliable low latency communications (URLLC), side-link device-to-device (D2D), and several other use cases.

[0006] Figure 1 illustrates a high-level view of an exemplary 5G network architecture, consisting of a Next Generation Radio Access Network (NG-RAN, 199) and a 5G Core (5GC, 198). The NG-RAN can include one or more gNodeB’s (gNBs) connected to the 5GC via one or more NG interfaces, such as gNBs (100, 150) connected via respective interfaces (102, 152). More specifically, the gNBs can be connected to one or more Access and Mobility Management Functions (AMFs) in the 5GC via respective NG-C interfaces and to one or more User Plane Functions (UPFs) in 5GC via respective NG-U interfaces. The 5GC can include various other network functions (NFs), such as Session Management Function(s) (SMF).

[0007] In addition, the gNBs can be connected to each other via one or more Xn interfaces, such as Xn interface (140) between gNBs (100, 150). The radio technology for the NG-RAN is often referred to as “New Radio” (NR). With respect to the NR interface to user equipment (UEs), each of the gNBs can support frequency division duplexing (FDD), time division duplexing (TDD), or a combination thereof. Each of the gNBs can serve a geographic coverage area including one or more cells and, in some cases, can also use various directional beams to provide coverage in the respective cells. In general, a DL “beam” is a coverage area of a network-transmitted reference signal (RS) that may be measured or monitored by a UE.

[0008] NG RAN logical nodes (e.g., gNB 100) may include a Central Unit (CU or gNB-CU, e.g., 110) and one or more Distributed Units (DU or gNB-DU, e.g., 120, 130). CUs are logical nodes that host higher-layer protocols and perform various gNB functions such controlling the operation of DUs. DUs are decentralized logical nodes that host lower layer protocols and can include, depending on the functional split option, various subsets of the gNB functions. Each CU and DU can include various circuitry needed to perform their respective functions, including processing circuitry, communication interface circuitry (e.g., transceivers), and power supply circuitry. A CU connects to its DUs over respective Fl logical interfaces (e.g., 122 and 132 shown in Figure 1). However, a gNB-DU can be connected to only a single gNB-CU.

[0009] To support communication from UE to RAN, a UE reports status of its buffers containing data awaiting UL transmission to the RAN. The UE reports this information in a medium access control (MAC) message called a buffer status report (BSR). The following BSR formats are used by UEs depending on various factors:

[0010] • Short BSR format (fixed size),

[0011] • Short Truncated BSR format (fixed size),

[0012] • Long Truncated BSR format (variable size), and

[0013] • Long BSR format (variable size).

[0014] After receiving a BSR, a RAN node can adjust scheduling of UE UL transmissions accordingly.

[0015] Extended Reality (XR) and cloud gaming are some of the most important 5G media applications under consideration. XR is an umbrella term that refers to all real-and-virtual combined environments and human-machine interactions generated by computer technology and wearables. It includes exemplary forms such as Augmented Reality (AR), Mixed Reality (MR), and Virtual Reality (VR), as well as various other types that span or sit between these examples. In the following, the term “XR” also refers to cloud gaming and related applications. In general, XR services require relatively high throughput (e.g., bit rates) and a latency that is relatively low and bounded, compared to certain other services.

[0016] 3 GPP Rel-17 included a study item on XR Evaluations for NR, with the main objectives being to identify the traffic model for each application of interest, the evaluation methodology and the key performance indicators of interest for relevant deployment scenarios, and to carry out performance evaluations to investigate possible standardization enhancements in follow-up study or work items in Rel-18.

[0017] SUMMARY

[0018] An application protocol data unit (PDU, e.g., a video frame) may be divided into multiple lower-layer packets, such as Internet Protocol (IP) packets. In such cased, all IP packets associated with a single application PDU are referred to as a “PDU set.” 3GPP has previously agreed that each PDU set may be assigned a PDU Set Importance (PSI) indicator whose value corresponds to level of importance of a PDU Set within a quality-of-service (QoS) flow. Additionally, 3 GPP has agreed that the RAN may use PSI information for selective discarding of PDU sets in the presence of network congestion. Currently, however, there is no way for a UE to report PSI (or similar information) for UL packets in UE buffers, nor for the RAN to use such information if reported.

[0019] An object of embodiments of the present disclosure is to improve reporting and usage of PSI-related information for UL packets, thereby providing, enabling, and / or facilitating solutions to exemplary problems summarized above and described in more detail below.

[0020] Some embodiments include methods (e.g., procedures) for a UE configured to transmit application data to a RAN node (e.g., gNB).

[0021] These exemplary methods include buffering data generated by an application hosted by the UE. The buffered data comprises a plurality of sets of protocol data units (PDUs), with each buffered PDU set being associated with the following: a logical channel group (LCG), at least one importance level, and a packet data convergence protocol (PDCP) discard timer. These exemplary methods also include transmitting a message to the RAN node that indicates the following:

[0022] • at least one LCG associated with buffered PDU sets; and

[0023] • delay information and one or more importance levels the buffered PDU sets associated with the indicated at least one LCG.

[0024] Other embodiments include exemplary methods (e.g., procedures) for a RAN node (e.g., gNB) configured to receive application data from a UE. These embodiments are generally complementary to UE embodiments summarized above.

[0025] These exemplary methods include receiving from the UE a message pertaining to buffered data generated by an application hosted by the UE. The buffered data comprises a plurality of sets of PDUs, with each buffered PDU set being associated with the following: an LCG, at least one importance level, and a PDCP discard timer. The message indicates the following:

[0026] • at least one LCG associated with buffered PDU sets; and

[0027] • delay information and one or more importance levels for the buffered PDU sets associated with the indicated at least one LCG.

[0028] The following applies to both UE and RAN node embodiments summarized above. In some embodiments, the message includes an initial octet of bits, with the bits of the initial octet being associated with respective ones of a plurality of LCGs. Each bit in the initial octet indicates whether the message indicates the delay information and the one or more importance levels associated with the buffered PDU sets for the associated LCG. In some embodiments, the delay information includes the following:

[0029] • a shortest remaining time on PDCP discard timers associated with the buffered PDU sets for the indicated LCG; and

[0030] • an amount of delay-critical data in the buffered PDU sets for the indicated LCG. In some of these embodiments, for each LCG indicated by the initial octet, the message includes a pair of adjacent octets arranged as:

[0031] • a first octet that includes indications of the one or more importance levels and the shortest remaining time on PDCP discard timers associated with the buffered PDU sets for the indicated LCG; and

[0032] • a second octet that indicates the amount of delay-critical data in the buffered PDU sets for the indicated LCG.

[0033] In some variants of these embodiments, for each LCG indicated by the initial octet, the first octet for the LCG indicates one of the following:

[0034] • a single importance level of the buffered PDU sets for the LCG;

[0035] • multiple different importance levels of the buffered PDU sets for the LCG; or

[0036] • whether the message also includes a subsequent pair of adjacent octets for the LCG.

[0037] In some further variants, the indicated single importance level is one of the following

[0038] • a highest importance level of the buffered PDU sets for the LCG;

[0039] • a lowest importance level of the buffered PDU sets for the LCG; or

[0040] • an importance level having the most buffered data in the buffered PDU sets for the LCG.

[0041] In some further variants, when first octet for the LCG indicates the single importance level, the second octet indicates the amount of delay-critical data of the single importance level in the buffered PDU sets for the LCG. In some further variants, the first octet for the LCG includes a bit field of a plurality of bits, and respective values of the bit field indicate one of the following:

[0042] • respective one or more importance levels of the buffered PDU sets for the LCG; or

[0043] • respective portions of the buffered PDU sets for the LCG that are of highest importance level.

[0044] In some further variants, the plurality of bits in the bit field of the first octet include a first bit that is configurable by the RAN node to be used as either of the following: a buffer size mapping table indicator bit (e.g., BT), or an importance level indicator bit.

[0045] In other variants of these embodiments, when the first octet for the LCG indicates that the message also includes a subsequent pair of adjacent octets for the LCG, the first octet indicates the shortest remaining time on PDCP discard timers associated with the buffered PDU sets of a highest importance level for the LCG. Also, the second octet indicates the amount of delay-critical data of the highest importance level in the buffered PDU sets for the LCG.

[0046] In some further variants, when the first octet for the LCG indicates that the message also includes a subsequent pair of adjacent octets for the LCG, the subsequent pair of octets is arranged as follows: • a third octet that indicates the following: whether the message also includes another subsequent pair of adjacent octets for the LCG, and the shortest remaining time on PDCP discard timers associated with the buffered PDU sets of a next highest importance level for the LCG; and

[0047] • a fourth octet that indicates an amount of delay-critical data of the next highest importance level in the buffered PDU sets for the indicated LCG.

[0048] In other embodiments, for each LCG indicated by the initial octet, the message includes one or more pairs of adjacent octets for the LCG, with each pair arranged as:

[0049] • a first octet that indicates the shortest remaining time on PDCP discard timers associated with the buffered PDU sets for the indicated LCG, and

[0050] • a second octet that indicates the amount of delay-critical data in the buffered PDU sets for the indicated LCG.

[0051] The message also includes a bit field in a further octet located in the message after the initial octet but before the one or more pairs of adjacent octets for the LCG, wherein the bit field indicates the one or more importance levels for the indicated LCG.

[0052] In some of these embodiments, the bit field is the entire further octet, such that for each LCG indicated by the initial octet, the message includes a corresponding further octet located after the initial octet but before any pairs of adjacent octets for the indicated LCGs.

[0053] In some of these embodiments, when the bit field in the further octet indicates a plurality of importance levels for the LCG, the message includes a corresponding plurality of pairs of adjacent octets for the LCG. Each first octet indicates the shortest remaining time on PDCP discard timers associated with the buffered PDU set of the corresponding importance level for the LCG. Each second octet indicates the amount of delay-critical data in the buffered PDU sets of the corresponding importance level for the indicated LCG. In some variants of these embodiments, the plurality of pairs of adjacent octets for the LCG are adjacent in the message, and are arranged in increasing or decreasing order of corresponding importance level.

[0054] In other embodiments, for each LCG indicated by the initial octet, the first octet for the LCG includes an importance level indicator bit. The importance level indicator bits for all LCGs indicated by the initial octet are logically combined into a bit field that indicates one or more importance levels associated with the buffered PDU sets for the indicated LCGs. In some of these embodiments, the logically combined bit field indicates one of the following:

[0055] • a percentage or amount of buffered PDU sets for all indicated LCGs, that is high importance or delay-critical; or

[0056] • respective percentages or amounts of buffered PDU sets for the respective indicated LCGs, that is high importance or delay-critical. Other embodiments and variants of the exemplary methods summarized above are described herein. Other embodiments include UEs (e.g., wireless devices) and RAN nodes (e.g., base stations, eNBs, gNBs, ng-eNBs, etc., or components thereof) configured to perform operations corresponding to any of the exemplary methods described herein. Other embodiments include non-transitory, computer-readable media storing program instructions that, when executed by processing circuitry, configure such UEs or RAN nodes to perform operations corresponding to any of the exemplary methods described herein.

[0057] These and other embodiments described herein provide a RAN with importance information (e.g., PSI) about data buffered by served UEs, which may be useful for RAN configuration and / or activation of UE features such as PSI-based discarding. Moreover, such importance information may also facilitate the RAN’s dynamic scheduling of its resources for UEs, through which the performance for the applications will be improved by more reliable reception of higher importance PDU sets. At a high level, embodiments facilitate and / or improve delivery of XR services via wireless networks (e.g., RANs).

[0058] These and other objects, features, and advantages of embodiments of the present disclosure will become apparent upon reading the following Detailed Description in view of the Drawings briefly described below.

[0059] BRIEF DESCRIPTION OF THE DRAWINGS

[0060] Figures 1-2 illustrate two high-level views of an exemplary 5G / NR network architecture.

[0061] Figure 3 shows exemplary NR user plane (UP) and control plane (CP) protocol stacks.

[0062] Figure 4 illustrates a comparison of various characteristics or requirements between Extended Reality (XR) and other 5G applications.

[0063] Figure 5 shows an example of frame latency measured over a RAN (e.g., NG-RAN).

[0064] Figure 6 shows exemplary cumulative distribution functions (CDFs) for the number of transport blocks (TBs) on the NR PHY required to deliver video frames of various sizes.

[0065] Figure 7 shows a comparison of arrival times between XR, voice-over-IP (VoIP), and web browsing traffic.

[0066] Figures 8A-B show two exemplary buffer status report (BSR) formats.

[0067] Figure 9 shows an exemplary delay status report (DSR) format.

[0068] Figures 10-11 show various exemplary octet arrangements for MAC CEs that include importance information, according to various embodiments of the present disclosure.

[0069] Figure 12 shows a flow diagram of an exemplary method for a UE e.g., wireless device), according to various embodiments of the present disclosure. Figure 13 shows a flow diagram of an exemplary method for a RAN node (e.g., base station, eNB, gNB, ng-eNB, etc.), according to various embodiments of the present disclosure.

[0070] Figure 14 shows a communication system according to various embodiments of the present disclosure.

[0071] Figure 15 shows a UE according to various embodiments of the present disclosure.

[0072] Figure 16 shows a network node according to various embodiments of the present disclosure.

[0073] Figure 17 is a block diagram of a virtualization environment in which functions implemented by some embodiments of the present disclosure may be virtualized.

[0074] DETAILED DESCRIPTION

[0075] Some of the embodiments contemplated herein will now be described more fully with reference to the accompanying drawings. Other embodiments, however, are contained within the scope of the subject matter disclosed herein, the disclosed subject matter should not be construed as limited to only the embodiments set forth herein; rather, these embodiments are provided by way of example to convey the scope of the subject matter to those skilled in the art.

[0076] In general, all terms used herein are to be interpreted according to their ordinary meaning to a person of ordinary skill in the relevant technical field, unless a different meaning is expressly defined and / or implied from the context of use. All references to a / an / the element, apparatus, component, means, step, etc. are to be interpreted openly as referring to at least one instance of the element, apparatus, component, means, step, etc., unless explicitly stated otherwise or clearly implied from the context of use. The operations of any methods and / or procedures disclosed herein do not have to be performed in the exact order disclosed, unless an operation is explicitly described as following or preceding another operation and / or where it is implicit that an operation must follow or precede another operation. Any feature of any embodiment disclosed herein can apply to any other disclosed embodiment, as appropriate. Likewise, any advantage of any embodiment described herein can apply to any other disclosed embodiment, as appropriate.

[0077] Furthermore, the following terms are used throughout the description given below:

[0078] • Radio Access Node: As used herein, a “radio access node” (or equivalently “radio network node,” “radio access network node,” or “RAN node”) can be any node in a radio access network (RAN) that operates to wirelessly transmit and / or receive signals. Some examples of a radio access node include, but are not limited to, a base station (e.g., gNB in a 3 GPP 5G / NR network or an enhanced or eNB in a 3GPP LTE network), base station distributed components (e.g., CU and DU), a high-power or macro base station, a low-power base station (e.g., micro, pico, femto, or home base station, or the like), an integrated access backhaul (IAB) node, a transmission point (TP), a transmission reception point (TRP), a remote radio unit (RRU or RRH), and a relay node.

[0079] • Core Network Node: As used herein, a “core network node” is any type of node in a core network. Some examples of a core network node include, e.g., a Mobility Management Entity (MME), a serving gateway (SGW), a PDN Gateway (P-GW), a Policy and Charging Rules Function (PCRF), an access and mobility management function (AMF), a session management function (SMF), a user plane function (UPF), a Charging Function (CHF), a Policy Control Function (PCF), an Authentication Server Function (AUSF), a location management function (LMF), or the like.

[0080] • Wireless Device: As used herein, a “wireless device” (or “WD” for short) is any type of device that is capable, configured, arranged and / or operable to communicate wirelessly with network nodes and / or other wireless devices. Communicating wirelessly can involve transmitting and / or receiving wireless signals using electromagnetic waves, radio waves, infrared waves, and / or other types of signals suitable for conveying information through air. Unless otherwise noted, the term “wireless device” is used interchangeably herein with the term “user equipment” (or “UE” for short), with both of these terms having a different meaning than the term “network node”.

[0081] • Radio Node: As used herein, a “radio node” can be either a “radio access node” (or equivalent term) or a “wireless device.”

[0082] • Network Node: As used herein, a “network node” is any node that is either part of the radio access network (e.g., a radio access node or equivalent term) or of the core network (e.g., a core network node discussed above) of a cellular communications network. Functionally, a network node is equipment capable, configured, arranged, and / or operable to communicate directly or indirectly with a wireless device and / or with other network nodes or equipment in the cellular communications network, to enable and / or provide wireless access to the wireless device, and / or to perform other functions (e.g., administration) in the cellular communications network.

[0083] • Node: As used herein, the term “node” (without prefix) can be any type of node that can in or with a wireless network (including RAN and / or core network), including a radio access node (or equivalent term), core network node, or wireless device. However, the term “node” may be limited to a particular type (e.g., radio access node, IAB node) based on its specific characteristics in any given context.

[0084] The above definitions are not meant to be exclusive. In other words, various ones of the above terms may be explained and / or described elsewhere in the present disclosure using the same or similar terminology. Nevertheless, to the extent that such other explanations and / or descriptions conflict with the above definitions, the above definitions should control.

[0085] Note that the description given herein focuses on a 3 GPP cellular communications system and, as such, 3GPP terminology or terminology similar to 3GPP terminology is oftentimes used. However, the concepts disclosed herein are not limited to a 3GPP system and can be applied to any communication system that may benefit from them.

[0086] Figure 2 shows another high-level view of an exemplary 5G network architecture, including an NG-RAN (299) and a 5GC (298). As shown in the figure, the NG-RAN can include gNBs (e.g., 210a,b) and ng-eNBs (e.g., 220a, b) that are interconnected with each other via respective Xn interfaces. An ng-eNB is similar to a fourth generation (4G) Long-Term Evolution (LTE) eNB, except that it supports the Xn and NG interfaces rather than corresponding X2 and SI interfaces.

[0087] The gNBs and ng-eNBs are also connected via the NG interfaces to the 5GC, more specifically to AMFs ( e.g., 230a, b) via respective NG-C interfaces and to UPFs (e.g., 240a, b) via respective NG-U interfaces. Moreover, the AMFs can communicate with one or more policy control functions (PCFs, e.g., 250a, b) and network exposure functions (NEFs, e.g., 260a, b).

[0088] Each of the gNBs can support the NR radio interface including frequency division duplexing (FDD), time division duplexing (TDD), or a combination thereof. Each of ng-eNBs can support the 4G / LTE radio interface. Each of the gNBs and ng-eNBs can serve a geographic coverage area including one or more cells (e.g., 211a-b and 221a-b). Depending on the cell in which it is located, UEs (e.g., 205) can communicate with the gNB or ng-eNB serving that cell via the NR or LTE radio interface, respectively. Although Figure 2 shows gNBs and ng-eNBs separately, it is also possible that a single NG-RAN node provides both LTE and NR functionality.

[0089] 5G / NR technology shares many similarities with fourth-generation LTE. For example, NR uses CP-OFDM (Cyclic Prefix Orthogonal Frequency Division Multiplexing) in the DL and both CP-OFDM and DFT-spread OFDM (DFT-S-OFDM) in the UL. As another example, in the time domain, NR DL and UL physical resources are organized into equal-sized 1-ms subframes. A subframe is further divided into multiple slots of equal duration, with each slot including multiple OFDM-based symbols. An NR slot can include 14 OFDM symbols for normal cyclic prefix and 12 symbols for extended cyclic prefix. A resource block (RB) consists of a group of 12 contiguous OFDM subcarriers for a duration of a 12- or 14-symbol slot. A resource element (RE) corresponds to one OFDM subcarrier during one OFDM symbol interval.

[0090] Figure 3 shows exemplary NR user plane (UP) and control plane (CP) protocol stacks between a UE (310), a gNB (320), and an AMF (330), such as those shown in Figures 1-2. The Physical (PHY), Medium Access Control (MAC), Radio Link Control (RLC), and Packet Data Convergence Protocol (PDCP) layers between the UE and the gNB are common to UP and CP. PDCP provides ciphering / deciphering, integrity protection, sequence numbering, reordering, and duplicate detection for both CP and UP. In addition, PDCP provides header compression and retransmission for UP data.

[0091] On the UP side, Internet protocol (IP) packets arrive to PDCP as service data units (SDUs), and PDCP creates protocol data units (PDUs) to deliver to RLC. The Service Data Adaptation Protocol (SDAP) layer handles quality-of-service (QoS) including mapping between QoS flows and Data Radio Bearers (DRBs) and marking QoS flow identifiers (QFI) in UE and DL packets.

[0092] When each IP packet arrives, PDCP starts a discard timer. When this timer expires, PDCP discards the associated SDU and the corresponding PDU. If the PDU was delivered to RLC, PDCP also indicates the discard to RLC. The RLC layer transfers PDCP PDUs to the MAC through logical channels (LCH). RLC provides error detection / correction, concatenation, segmentation / reassembly, sequence numbering, reordering of data transferred to / from the upper layers. If RLC receives a discard indication from associated with a PDCP PDU, it will discard the corresponding RLC SDU (or any segment thereof) if it has not been sent to lower layers.

[0093] MAC provides mapping between LCHs and PHY transport channels, LCH prioritization, multiplexing into or demultiplexing from transport blocks (TBs), hybrid ARQ (HARQ) error correction, and dynamic scheduling (in gNB). PHY provides transport channel services to MAC and handles transfer over the NR radio interface, e.g., via modulation, coding, antenna mapping, and beam forming.

[0094] On the CP side, the non-access stratum (NAS) layer between UE and AMF handles UE / gNB authentication, mobility management, and security control. RRC sits below NAS in the UE but terminates in the gNB rather than the AMF. RRC controls communications between UE and gNB at the radio interface as well as the mobility of a UE between cells in the NG-RAN. RRC also broadcasts system information (SI) and performs establishment, configuration, maintenance, and release of DRBs and Signaling Radio Bearers (SRBs) and used by UEs. Additionally, RRC controls addition, modification, and release of carrier aggregation (CA) and dual -connectivity (DC) configurations for UEs, and performs various security functions such as key management.

[0095] After a UE is powered ON it will be in the RRCJCDLE state until an RRC connection is established with the network, at which time the UE will transition to RRC CONNECTED state (e.g., where data transfer can occur). The UE returns to RRC IDLE after the connection with the network is released. In RRC IDLE state, the UE’s radio is active on a discontinuous reception (DRX) schedule configured by upper layers. During DRX active periods (also referred to as “DRX On durations”), an RRC IDLE UE receives SI broadcast in the cell where the UE is camping, performs measurements of neighbor cells to support cell reselection, and monitors a paging channel on PDCCH for pages from 5GC via gNB. An NR UE in RRC IDLE state is not known to the gNB serving the cell where the UE is camping. However, NR RRC includes an RRC_INACTIVE state in which a UE is known (e.g., via UE context) by the serving gNB. RRC INACTIVE has some properties similar to a “suspended” condition used in LTE.

[0096] In general, extended reality (XR) refers to all real-and-virtual combined environments and human-machine interactions generated by computer technology and wearables. It is an umbrella term for different environment types including Virtual reality (VR), Augmented reality (AR), Mixed reality (MR), and any environment types lying between these. The levels of virtuality range from partially sensory inputs to fully immersive VR.

[0097] 5G / NR is designed to support applications demanding high rate and low latency in line with the requirements for supporting XR and cloud gaming applications. 3 GPP Rel-17 includes a study item (SI) on XR Evaluations for NR. The main objectives are to identify the traffic model for each application of interest and the evaluation methodology and the key performance indicators of interest for relevant deployment scenarios, and to carry out performance evaluations accordingly in order to investigate possible standardization enhancements in potential follow-up SI or work item (WI).

[0098] Edge Computing (EC) can be a network architecture enabler for XR. In general, EC facilitates deployment of cloud computing capabilities and service environments close to the cellular radio access network (RAN). It can provide benefits such as lower latency and higher bandwidth for user-plane (UP, e.g., data) traffic, as well as reduced backhaul traffic to the 5G core network (5GC). 3GPP is also studying prospects for several new services on application architecture for enabling Edge Applications, as further described in 3GPP TR 23.758 (vl7.0.0).

[0099] Figure 4 illustrates a high-level comparison of various characteristics requirements for XR and other 5G applications. In particular, Figure 4 shows a comparison of latency, reliability, and data rate requirements for URLLC, streaming, and EC-based XR. While URLLC services have extreme requirements of 1-ms latency and of 10'5, EC-based XR can have relaxed requirements of 5-10 ms latency and 10'4reliability. However, XR services can require a much higher bite rate than either URLLC or streaming, (e.g., due to codec inefficiency). XR traffic can also be very dynamic, e.g., due to eye / viewport tracking.

[0100] XR requires bounded latency but not necessarily ultra-low latency. However, the end-to- end latency (or packet delay) budget (e.g., 20-80 ms) must be distributed over several components including application processing latency, transport latency, radio link latency, etc. For these applications, short transmission time intervals (TTIs) or mini slots may not be effective.

[0101] In general, XR traffic is relatively periodic in arrival time but average data rate requirement and dominant transmission direction (e.g., UL or DL) is dependent on the particular XR-related service. Table 1 below gives an exemplary characterization of XR services by data rate (or throughput) requirements and dominant transmission direction.

[0102] Table 1.

[0103] Figure 5 shows an example of frame latency measured over a radio access network (RAN, e.g., NG-RAN), excluding latencies of application and core network (CN, e.g., 5GC). This measured RAN latency is highly variable across three different users (i.e., 1-3) and time (i.e., 0- 1.6 s), with some spikes as high as 30 ms. The sources for the latency spikes may include queuing delay, time-varying radio environments, time-varying frame sizes, etc. Techniques that can mitigate, reduce, and / or eliminate such latency spikes are beneficial to NG-RAN support for XR traffic requiring bounded and / or predictable latency.

[0104] As briefly mentioned above, XR applications typically require high data rates. This is due to both high frame refresh rates and large video frame sizes that may range from tens to hundreds of kilobytes (kB). As a concrete example, a frame size of 100 kB and a frame refresh rate of 120 Hz can lead to a data rate requirement of 95.8 Mb / s.

[0105] Large video frames are usually fragmented into smaller Internet Protocol (IP) packets and transmitted as several transport blocks (TBs) over several TTIs in RAN. Figure 6 shows exemplary cumulative distribution functions (CDFs) for the number of transport blocks (TBs) on the NR PHY required to deliver a video frame of size ranging from 20 to 300 kB. For example, Figure 6 shows that for video frames of size 200 kB, the median number of TBs is 5 but in ~5% of the cases, 15 or more TBs are required to deliver a 200-kB video frame. A 1-ms TTI and 100-MHz carrier bandwidth is assumed in Figure 6.

[0106] Figure 7 shows a comparison of arrival times between XR, voice-over-IP (VoIP), and web browsing traffic. The characteristics of XR traffic arrival time is quasi-periodic and largely predictable. This is similar to VoIP but different than web browsing, in which arrival is very unpredictable. However, the size of XR traffic (e.g., video frames) is much larger than VoIP traffic, and can vary across arrivals due to dynamics of contents and human motion. As such, XR traffic shares some characteristics with web browsing traffic.

[0107] As briefly mentioned above, a UE reports the status of its buffers containing data waiting for UL transmission to the RAN. The UE reports this information in a MAC -layer control element (CE) called a buffer status report (BSR). The following BSR formats are used by UEs depending on various factors: • Short BSR format (fixed size),

[0108] • Short Truncated BSR format (fixed size),

[0109] • Long Truncated BSR format (variable size), and

[0110] • Long BSR format (variable size).

[0111] After receiving a BSR, a RAN node can adjust scheduling of UE UL transmissions accordingly.

[0112] Figure 8 A shows the format used for short and short truncated BSRs. This format includes a single octet carrying three (3) bits indicating a logical channel group (LCG) ID for which data is buffered, and five (5) bits indicating a size of the data buffered for the LCG ID.

[0113] Figure 8B shows the format used for long and long truncated BSRs. This format includes one octet (Oct 1) that includes a bitmap in which each bit maps to a particular LCG ID, and multiple octets (2 to m+1) indicating sizes of buffered data for various LCG IDs. A bit value of “1” indicates that buffered data for the corresponding LCG ID is reported in one of octets 2 to m+1, while a bit value of “0” indicates that buffered data for the corresponding LCG ID is not reported.

[0114] There are three (3) types of BSRs: regular, periodic, and padding. A regular BSR is triggered if UL data, for a logical channel which belongs to an LCG, becomes available to the MAC entity and one of the following is true:

[0115] • this UL data belongs to a logical channel with higher priority than the priority of any logical channel containing available UL data which belong to any LCG; or

[0116] • none of the logical channels which belong to an LCG contains any available UL data.

[0117] When more than one LCG has data available for transmission, the UE uses the long BSR format and reports all LCGs which have data. In contrast, a UE uses short BSR format when only one LCG has data available for transmission.

[0118] Periodic BSR is configured by the RAN (e.g., serving gNB), including a reporting period. Similar to regular BSR, when more than one LCG has data available for transmission, the UE uses the long BSR format and reports all LCGs which have data. In contrast, a UE uses short BSR format when only one LCG has data available for transmission.

[0119] Padding BSR is an opportunistic method for the UE to provide buffer status information to the RAN when a MAC-layer PDU contains a number of padding (i.e., non-data) bits equal or larger than one of the BSR formats. In this case, the UE replaces the padding bits with a padding BSR having a format that corresponds (i.e., is no larger than) the number of padding bits. Note that one MAC PDU can contain no more than one BSR MAC CE.

[0120] Additionally, the padding BSR format depends on the number of logical channels that have data available for transmissions. When more than one LCG has data for transmission, the padding BSR uses a short truncated, long, or long truncated BSR format, depending on the number of available padding bits. When only one LCG has data for transmission, the padding BSR uses the short BSR format.

[0121] A 3GPP Rel-18 work item (WI) for XR introduced a delay status reporting (DSR), which is handled separately from BSR. Figure 9 shows an example DSR format. Similar to Figure 8B, octet 1 includes a bitmap in which each bit maps to a particular LCG ID. A bit value of “1” in octet 1 indicates that delay information for the corresponding LCG ID is included in subsequent octets, while a bit value of “0” indicates that that delay information for the corresponding LCG ID is not included in in the message.

[0122] Assuming m (<8) LCG IDs with included delay information, the delay information is included in octets 2 to 2m+l, with the delay information for each LCG being included in two consecutive octets (e.g., 2-3), arranged in ascending order based on LCG. The second of these two octets contains a Buffer Size field, which indicates a total amount of delay-critical UL data (in bytes) for the LCG (i.e., according to the data volume calculation procedure specified in clause 3GPP TS 38.322 (vl7.3.0) section 5.5 and 3GPP TS 38.323 (vl7.5.0) section 5.6 for the associated RLC and PDCP entities, respectively) after the MAC PDU has been built.

[0123] The first of these two octets includes a BT field, which is present only if the corresponding LCG is configured with additionalBSR-Table Allowed, otherwise, this field is reserved. If present, the BT field set to 1 indicates that the buffer sizes specified in 3GPP TS 38.321 Table 6.1.3.1-x are used to set the value of the Buffer Size field in octet 2, while the BT field set to 0 indicates that the buffer sizes specified in 3GPP TS 38.321 Table 6.1.3.1-2 are used instead.

[0124] The first of these two octets also includes a Remaining Time field, which indicates the shortest remaining value of PDCP discardTimer (described in 3GPP 38.323 section 7.3) among all PDCP SDUs buffered for an LCG, at the time of the first symbol of the first PUSCH transmission that includes this DSR MAC CE. The length of each Remaining Time field is 6 bits, with any value r in this field indicating a remaining time within the range of (r, r + 1] msec.

[0125] In other words, if the corresponding LCG is configured with additionalBSR-Table Allowed and the amount of delay-critical UL data for an LCG is within the buffer sizes specified in Table 6.1.3.1-x, the MAC entity shall use the buffer sizes specified in Table 6.1.3.1-x to set the value of the Buffer Size field for the LCG. Otherwise, the MAC entity shall use Table 6.1.3.1-2 instead.

[0126] The first octet of each consecutive pair of octets associated with an LCG also includes a reserved bit (R), which is currently unused and undefined.

[0127] An application protocol data unit (PDU, e.g. a video frame) may be divided into multiple lower-layer packets, such as IP packets. In such cased, all IP packets associated with a single application PDU are referred to as a “PDU set.” More specifically, 3GPP TR 23.700-60 (vl 8.0.0) specifies that a “PDU set” is composed of one or more PDUs carrying the payload of one unit of information generated at the application level (e.g. a frame or video slice for XRM Services, as used in 3GPP TR 26.926 (vl9.1.0). In some cases, all PDUs in a PDU set are needed by the application in order to use the corresponding information unit. In other cases, the application can still recover all or part of the information unit, even when one or more of the PDUs of the PDU set are missing.

[0128] 3 GPP has previously agreed that each PDU set may be assigned a PDU set importance (PSI) indicator whose value corresponds to level of importance of a PDU set within a quality-of- service (QoS) flow associated with an application. In other words, PSI indicates how useful the PDU set is for the application, with low importance PDU sets be more amenable to discard by the network than high importance PDU sets, which should be retained.

[0129] A 3GPP Rel-18 work item (WI) for XR introduced UL PSI based discarding. This solution is completely dependent on the UE to identify PSI levels of respective PDU sets, determine what is a low or high importance PDU set, and then applies network-configured discard behavior for each buffered PDU set depending on its determined importance. Although the RAN can obtain delay information based on DSR, no information about the importance of the PDU sets is delivered to the RAN. Since the RAN decides when to use the PSI level based discarding in the UL, and also when to schedule certain UEs, this missing information about the importance of the packets in the UE buffers can be useful to the network.

[0130] Accordingly, embodiments of the present disclosure provide flexible and efficient techniques for a UE to include PSI (or similar importance information) in various delay status reports. Moreover, other embodiments provide techniques for a RAN to configure a UE to provide importance information, and to use importance information received from UEs in various RAN functions.

[0131] Embodiments can provide various benefits and / or advantages. For example, embodiments may provide the RAN with importance information (e.g., PSI) about data buffered by served UEs, which may be useful for RAN configuration and / or activation of UE features such as PSLbased discarding. Moreover, such importance information may also facilitate the RAN’s dynamic scheduling of its resources for UEs, through which the performance for the applications will be improved by more reliable reception of higher importance PDU sets. At a high level, embodiments facilitate delivery of XR services via wireless networks (e.g., RANs).

[0132] In various embodiments, importance information (or indication) for a PDU set can be reported by one or more bits. For example, four bits would be needed to report any of the 16 currently defined PSI levels. In contrast, only one bit would be needed to indicate whether a buffered PDU set is of low or high importance In some embodiments, a legacy DSR such as shown in Figure 9 can be modified to include importance information. Figure 10 shows an octet arrangement for a DSR MAC CE in accordance with these embodiments. In this example, the reserved bit (R) in the first octet of each consecutive pair of octets associated with an LCG is instead used as importance information (called Ixfor LCGX) to indicate with the associated data is of low or high importance. For example, Ix= 1 indicates the buffered data having size and remaining time indicated by other fields of the same two octets is of high importance, while Ix= 0 indicates the buffered data is of low importance. In some variants, the threshold between high and low importance may be RAN-configurable.

[0133] In other embodiments, the value of Ixcan be used to indicate whether one or multiple levels of importance are reported for the LCG. For example, Ix= 1 indicates that buffer size and remaining time is provided for buffered LCG data with high and low importance levels (i.e., in separate pairs of octets) while Ix= 0 indicates that buffer size and remaining time is provided for buffered LCG data a single importance level (e.g., high). In other words, when L = 1, the first two octets for LCGXinclude BT indicator, remaining time, and buffer size for high-importance PDUs (e.g., arranged as in Figure 10), while the next two octets for LCGXinclude BT indicator, remaining time, and buffer size for low-importance PDUs (e.g., arranged as in Figure 10). In some variants, the octet pairs can be ordered by increasing importance level, i.e., low then high.

[0134] In other embodiments, the value of Ixcan be used to indicate whether another level of importance is reported for the LCG after the current octet pair. For example, if the initial octet pair for LCGXis for the buffered data of the highest importance, Ix= 1 in that octet pair indicates that a second octet pair follows for buffered data of LCGXwith next highest importance. In case of only two importance levels, that second octet pair would be the last octet pair for LCGX„ so Ix= 0 in the second octet pair. However, this arrangement can be extended to as more importance levels as needed, such that Ix= 1 in the octet pairs for all except the lowest and last-reported importance level. In some variants, the octet pairs can be ordered by increasing importance level, i.e., low to high.

[0135] In some variants, Ix= 0 in the second octet pair for an LCG can be used to indicate that buffer sizes for any remaining lower (or higher) importance levels for the LCG are zero. In other words, the UE reports buffer sizes and remaining time for all importance levels down (or up) to some final level, and buffer sizes for other non-reported importance levels are implied to be zero.

[0136] Different solutions are possible for when the buffered data for an LCG contains both high and low importance data. In some embodiments, only one importance indication is used for all the buffered data for an LCG, with the reported value being the highest importance level among the buffered data. For example, if both high and low importance are in the LCG buffer then high importance is reported for the LCG. In other embodiments, a single importance indication can indicate that the reported buffered data contains a mixture of PDU sets with differing importance.

[0137] In other embodiments, importance level of buffered data for an LCG can be indicated by one or more octets that follow the initial LCG-indicating octet. The importance information is not added for LCGs not indicated as being reported, thereby reducing overhead. Figure 11 shows an octet arrangement for a DSR MAC CE in accordance with these embodiments. In this example, octet 2 is used to indicate important information for an LCG with buffered data. In particular, the importance information indicates the buffered data for the LCG is associated with first and second importance levels. Octets 3-4 include remaining time and buffer size for the first importance level, while octets 5-6 include remaining time and buffer size for the second importance level, both associated with the same LCG.

[0138] In other variants, the importance information in octet 2 of Figure 12 is associated with multiple LCGs indicated in octet 1 as having data, e.g., a four-bit field for a first LCG and another four-bit field for a second LCG. In such case, octets conveying remaining time and buffer size for all indicated importance levels for the first and second LCGs will follow octet 2, in a similar manner as illustrated in Figure 12.

[0139] In other embodiments, when more than one LCG with buffered data is indicated by the initial octet, the R-bits associated with the multiple LCGs with buffered data may be combined logically to form a single bit field that indicates high importance data across all of the multiple LCGs. For example, when two LCGs are indicated, the two R-bits can be combined to form an index to a four-entry table, with each entry indicating a total amount (or percentage) of high importance data for both LCGs. Alternately, each entry can indicate some amount (or percentage) of high importance data for each of the two LCGs.

[0140] Similarly, when three LCGs are indicated, the three R-bits can be combined to form an index to an eight-entry table, with each entry indicating a total amount (or percentage) of high importance data for all thee LCGs. Alternately, each entry can indicate some amount (or percentage) of high importance data for each of the three LCGs..

[0141] In other embodiments, the RAN can configure a UE to always use one of the two table options for mapping buffered data to buffer size fields, thereby freeing the BT bit to be used for reporting of importance information. For example, in the context of Figure 10, the adjacent BT and R bits in each even numbered octet can be used to indicate importance information together with the remaining time and buffer size for the associated LCG. In this manner, at least four different importance levels can be indicated.

[0142] In other embodiments, the importance information can indicate a percentage or portion of the data indicated by the buffer size field for the LCG is of high importance. Table 2 below shows an example relationship between two-bit values of importance information and percentage ranges for high-importance data indicated by the buffer size field for the LCG. Other percentage ranges can be used as needed.

[0143] Table 2.

[0144] Various features of the embodiments described above correspond to various operations illustrated in Figures 12-13, which show exemplary methods (e.g., procedures) for a UE and a RAN node, respectively. In other words, various features of the operations described below correspond to various embodiments described above. Furthermore, the exemplary methods shown in Figures 12-13 can be used cooperatively to provide various benefits, advantages, and / or solutions to problems described herein. Although Figures 12-13 show specific blocks in particular orders, the operations of the exemplary methods can be performed in different orders than shown and can be combined and / or divided into blocks having different functionality than shown. Optional blocks or operations are indicated by dashed lines.

[0145] In particular, Figure 12 shows an exemplary method (e.g., procedure) for a UE configured to transmit application data to a RAN node, according to various embodiments of the present disclosure. The exemplary method can be performed by a UE (e.g., wireless device, loT device, etc.) such as described elsewhere herein.

[0146] The exemplary method includes the operations of block 1220, where the UE buffers data generated by an application hosted by the UE. The buffered data comprises a plurality of sets of protocol data units (PDUs), with each buffered PDU set being associated with the following: a logical channel group (LCG), at least one importance level, and a packet data convergence protocol (PDCP) discard timer. The exemplary method also includes the operations of block 1230, where the UE transmits a message to the RAN node that indicates the following:

[0147] • at least one LCG associated with buffered PDU sets; and

[0148] • delay information and one or more importance levels for the buffered PDU sets associated with the indicated at least one LCG.

[0149] In some embodiments, the message includes an initial octet of bits, with the bits of the initial octet being associated with respective ones of a plurality of LCGs. Each bit in the initial octet indicates whether the message indicates the delay information and the one or more importance levels associated with the buffered PDU sets for the associated LCG. In some embodiments, the delay information includes the following:

[0150] • a shortest remaining time on PDCP discard timers associated with the buffered PDU sets for the indicated LCG; and

[0151] • an amount of delay-critical data in the buffered PDU sets for the indicated LCG.

[0152] In some of these embodiments, for each LCG indicated by the initial octet, the message includes a pair of adjacent octets arranged as:

[0153] • a first octet that includes indications of the one or more importance levels and the shortest remaining time on PDCP discard timers associated with the buffered PDU sets for the indicated LCG; and

[0154] • a second octet that indicates the amount of delay-critical data in the buffered PDU sets for the indicated LCG.

[0155] Figure 10 shows an example of these embodiments. In some variants of these embodiments, for each LCG indicated by the initial octet, the first octet for the LCG indicates one of the following:

[0156] • a single importance level of the buffered PDU sets for the LCG;

[0157] • multiple different importance levels of the buffered PDU sets for the LCG; or

[0158] • whether the message also includes a subsequent pair of adjacent octets for the LCG.

[0159] In some further variants, the indicated single importance level is one of the following

[0160] • a highest importance level of the buffered PDU sets for the LCG;

[0161] • a lowest importance level of the buffered PDU sets for the LCG; or

[0162] • an importance level having the most buffered data in the buffered PDU sets for the LCG.

[0163] In some further variants, when first octet for the LCG indicates the single importance level, the second octet indicates the amount of delay-critical data of the single importance level in the buffered PDU sets for the LCG. In some further variants, the first octet for the LCG includes a bit field of a plurality of bits, and respective values of the bit field indicate one of the following:

[0164] • respective one or more importance levels of the buffered PDU sets for the LCG; or

[0165] • respective portions of the buffered PDU sets for the LCG that are of highest importance level.

[0166] Table 2 above shows an example of the second option in the above list.

[0167] In some further variants, the plurality of bits in the bit field of the first octet include a first bit that is configurable by the RAN node to be used as either of the following: a buffer size mapping table indicator bit (e.g., BT), or an importance level indicator bit. In other variants of these embodiments, when the first octet for the LCG indicates that the message also includes a subsequent pair of adjacent octets for the LCG, the first octet indicates the shortest remaining time on PDCP discard timers associated with the buffered PDU sets of a highest importance level for the LCG. Also, the second octet indicates the amount of delay-critical data of the highest importance level in the buffered PDU sets for the LCG.

[0168] In some further variants, when the first octet for the LCG indicates that the message also includes a subsequent pair of adjacent octets for the LCG, the subsequent pair of octets is arranged as follows:

[0169] • a third octet that indicates the following: whether the message also includes another subsequent pair of adjacent octets for the LCG, and the shortest remaining time on PDCP discard timers associated with the buffered PDU sets of a next highest importance level for the LCG; and

[0170] • a fourth octet that indicates an amount of delay-critical data of the next highest importance level in the buffered PDU sets for the indicated LCG.

[0171] In other embodiments, for each LCG indicated by the initial octet, the message includes one or more pairs of adjacent octets for the LCG, with each pair arranged as:

[0172] • a first octet that indicates the shortest remaining time on PDCP discard timers associated with the buffered PDU sets for the indicated LCG, and

[0173] • a second octet that indicates the amount of delay-critical data in the buffered PDU sets for the indicated LCG.

[0174] The message also includes a bit field in a further octet located in the message after the initial octet but before the one or more pairs of adjacent octets for the LCG, wherein the bit field indicates the one or more importance levels for the indicated LCG.

[0175] In some of these embodiments, the bit field is the entire further octet, such that for each LCG indicated by the initial octet, the message includes a corresponding further octet located after the initial octet but before any pairs of adjacent octets for the indicated LCGs. Figure 11 shows an example of these embodiments.

[0176] In some of these embodiments, when the bit field in the further octet indicates a plurality of importance levels for the LCG, the message includes a corresponding plurality of pairs of adjacent octets for the LCG. Each first octet indicates the shortest remaining time on PDCP discard timers associated with the buffered PDU set of the corresponding importance level for the LCG. Each second octet indicates the amount of delay-critical data in the buffered PDU sets of the corresponding importance level for the indicated LCG. In some variants of these embodiments, the plurality of pairs of adjacent octets for the LCG are adjacent in the message, and are arranged in increasing or decreasing order of corresponding importance level. In other embodiments, for each LCG indicated by the initial octet, the first octet for the LCG includes an importance level indicator bit. The importance level indicator bits for all LCGs indicated by the initial octet are logically combined into a bit field that indicates one or more importance levels associated with the buffered PDU sets for the indicated LCGs. In some of these embodiments, the logically combined bit field indicates one of the following:

[0177] • a percentage or amount of buffered PDU sets for all indicated LCGs, that is high importance or delay-critical; or

[0178] • respective percentages or amounts of buffered PDU sets for the respective indicated LCGs, that is high importance or delay-critical.

[0179] In some embodiments, the exemplary method also includes the operations of block 1210, where the UE receives from the RAN node a reporting configuration that indicates one or more of the following:

[0180] • which importance levels should be reported for buffered PDU sets;

[0181] • which LCGs with associated buffered PDU sets should be reported;

[0182] • a threshold for distinguishing between high and low importance levels;

[0183] • reporting format to be used; and

[0184] • a buffer size mapping table to be used for reporting delay information.

[0185] The message transmitted to the RAN node in block 1230 is in accordance with the reporting configuration.

[0186] In some embodiments, the exemplary method also includes the operations of blocks 1260- 1270, where in response to the message, the UE receives from the RAN node a grant of uplink resources and transmits at least a portion of the buffered data to the RAN node, using the granted uplink resources.

[0187] In some embodiments, the exemplary method also includes the operations of block 1240, where in response to the message in block 1230, the UE receives from the RAN node a discard configuration indicating one or more of the following:

[0188] • one or more importance levels for which associated buffered PDU sets may be discarded, and

[0189] • one or more importance levels for which associated buffered PDU sets should not be discarded; and

[0190] In such embodiments, the exemplary method also includes the operations of block 1250, where the UE selectively discards the buffered PDU sets in accordance with the discard configuration.

[0191] In some embodiments, the message is a delay status report (DSR) medium access control (MAC) control element (CE). In some embodiments, the application is an extended reality (XR) application and the data generated by the application has a bounded latency requirement. In addition, Figure 13 shows an exemplary method (e.g., procedure) for a RAN node configured to receive application data from a UE, according to various embodiments of the present disclosure. The exemplary method can be performed by a RAN node (e.g., base station, eNB, gNB, ng-eNB, etc., or component thereof) such as described elsewhere herein.

[0192] The exemplary method includes the operations of block 1330, where the RAN node receives from the UE a message pertaining to buffered data generated by an application hosted by the UE. The buffered data comprises a plurality of sets of PDUs, with each buffered PDU set being associated with the following: an LCG, at least one importance level, and a PDCP discard timer. The message also indicates the following:

[0193] • at least one LCG associated with buffered PDU sets; and

[0194] • delay information and one or more importance levels for the buffered PDU sets associated with the indicated at least one LCG.

[0195] In some embodiments, the message includes an initial octet of bits, with the bits of the initial octet being associated with respective ones of a plurality of LCGs. Each bit in the initial octet indicates whether the message indicates the delay information and the one or more importance levels associated with the buffered PDU sets for the associated LCG. In some embodiments, the delay information includes the following:

[0196] • a shortest remaining time on PDCP discard timers associated with the buffered PDU sets for the indicated LCG; and

[0197] • an amount of delay-critical data in the buffered PDU sets for the indicated LCG.

[0198] In some of these embodiments, for each LCG indicated by the initial octet, the message includes a pair of adjacent octets arranged as:

[0199] • a first octet that includes indications of the one or more importance levels and the shortest remaining time on PDCP discard timers associated with the buffered PDU sets for the indicated LCG; and

[0200] • a second octet that indicates the amount of delay-critical data in the buffered PDU sets for the indicated LCG.

[0201] Figure 10 shows an example of these embodiments. In some variants of these embodiments, for each LCG indicated by the initial octet, the first octet for the LCG indicates one of the following:

[0202] • a single importance level of the buffered PDU sets for the LCG;

[0203] • multiple different importance levels of the buffered PDU sets for the LCG; or

[0204] • whether the message also includes a subsequent pair of adjacent octets for the LCG.

[0205] In some further variants, the indicated single importance level is one of the following

[0206] • a highest importance level of the buffered PDU sets for the LCG; • a lowest importance level of the buffered PDU sets for the LCG; or

[0207] • an importance level having the most buffered data in the buffered PDU sets for the LCG.

[0208] In some further variants, when first octet for the LCG indicates the single importance level, the second octet indicates the amount of delay-critical data of the single importance level in the buffered PDU sets for the LCG. In some further variants, the first octet for the LCG includes a bit field of a plurality of bits, and respective values of the bit field indicate one of the following:

[0209] • respective one or more importance levels of the buffered PDU sets for the LCG; or

[0210] • respective portions of the buffered PDU sets for the LCG that are of highest importance level.

[0211] Table 2 above shows an example of the second option in the above list.

[0212] In some further variants, the plurality of bits in the bit field of the first octet include a first bit that is configurable by the RAN node to be used as either of the following: a buffer size mapping table indicator bit (e.g., BT), or an importance level indicator bit.

[0213] In other variants of these embodiments, when the first octet for the LCG indicates that the message also includes a subsequent pair of adjacent octets for the LCG, the first octet indicates the shortest remaining time on PDCP discard timers associated with the buffered PDU sets of a highest importance level for the LCG. Also, the second octet indicates the amount of delay-critical data of the highest importance level in the buffered PDU sets for the LCG.

[0214] In some further variants, when the first octet for the LCG indicates that the message also includes a subsequent pair of adjacent octets for the LCG, the subsequent pair of octets is arranged as follows:

[0215] • a third octet that indicates the following: whether the message also includes another subsequent pair of adjacent octets for the LCG, and the shortest remaining time on PDCP discard timers associated with the buffered PDU sets of a next highest importance level for the LCG; and

[0216] • a fourth octet that indicates an amount of delay-critical data of the next highest importance level in the buffered PDU sets for the indicated LCG.

[0217] In other embodiments, for each LCG indicated by the initial octet, the message includes one or more pairs of adjacent octets for the LCG, with each pair arranged as:

[0218] • a first octet that indicates the shortest remaining time on PDCP discard timers associated with the buffered PDU sets for the indicated LCG, and

[0219] • a second octet that indicates the amount of delay-critical data in the buffered PDU sets for the indicated LCG. The message also includes a bit field in a further octet located in the message after the initial octet but before the one or more pairs of adjacent octets for the LCG, wherein the bit field indicates the one or more importance levels for the indicated LCG.

[0220] In some of these embodiments, the bit field is the entire further octet, such that for each LCG indicated by the initial octet, the message includes a corresponding further octet located after the initial octet but before any pairs of adjacent octets for the indicated LCGs. Figure 11 shows an example of these embodiments.

[0221] In some of these embodiments, when the bit field in the further octet indicates a plurality of importance levels for the LCG, the message includes a corresponding plurality of pairs of adjacent octets for the LCG. Each first octet indicates the shortest remaining time on PDCP discard timers associated with the buffered PDU set of the corresponding importance level for the LCG. Each second octet indicates the amount of delay-critical data in the buffered PDU sets of the corresponding importance level for the indicated LCG. In some variants of these embodiments, the plurality of pairs of adjacent octets for the LCG are adjacent in the message, and are arranged in increasing or decreasing order of corresponding importance level.

[0222] In other embodiments, for each LCG indicated by the initial octet, the first octet for the LCG includes an importance level indicator bit. The importance level indicator bits for all LCGs indicated by the initial octet are logically combined into a bit field that indicates one or more importance levels associated with the buffered PDU sets for the indicated LCGs. In some of these embodiments, the logically combined bit field indicates one of the following:

[0223] • a percentage or amount of buffered PDU sets for all indicated LCGs, that is high importance or delay-critical; or

[0224] • respective percentages or amounts of buffered PDU sets for the respective indicated LCGs, that is high importance or delay-critical.

[0225] In some embodiments, the exemplary method also includes the operations of block 1310, where the RAN node sends to the UE a reporting configuration that indicates one or more of the following:

[0226] • which importance levels should be reported for buffered PDU sets;

[0227] • which LCGs with associated buffered PDU sets should be reported;

[0228] • a threshold for distinguishing between high and low importance levels;

[0229] • reporting format to be used; and

[0230] • a buffer size mapping table to be used for reporting delay information.

[0231] The message received from the UE in block 1320 is in accordance with the reporting configuration. In some embodiments, the exemplary method also includes the operations of blocks 1340- 1350, where in response to the message, the RAN node sends to the UE a grant of uplink resources and receives at least a portion of the buffered data from the UE using the granted uplink resources.

[0232] In some embodiments, the exemplary method also includes the operations of block 1330, where the RAN node sends to the UE a discard configuration indicating one or more of the following: one or more importance levels for which associated buffered PDU sets may be discarded, and one or more importance levels for which associated buffered PDU sets should not be discarded.

[0233] In some embodiments, the message is a DSR MAC CE. In some embodiments, the application is an XR application and the data generated by the application has a bounded latency requirement.

[0234] Although various embodiments are described above in terms of methods, techniques, and / or procedures, the person of ordinary skill will readily comprehend that such methods, techniques, and / or procedures can be embodied by various combinations of hardware and software in various systems, communication devices, computing devices, control devices, apparatuses, non-transitory computer-readable media, computer program products, etc.

[0235] Figure 14 shows an example of a communication system 1400 in accordance with some embodiments. In this example, communication system 1400 includes a telecommunication network 1402 that includes an access network 1404 (e.g., RAN) and a core network 1406, which includes one or more core network nodes 1408. Access network 1404 includes one or more access network nodes, such as network nodes 1410a-b (one or more of which may be generally referred to as network nodes 1410), or any other similar 3 GPP access nodes or non-3GPP access points. Moreover, as will be appreciated by those of skill in the art, a network node is not necessarily limited to an implementation in which a radio portion and a baseband portion are supplied and integrated by a single vendor. Thus, it will be understood that network nodes include disaggregated implementations or portions thereof. For example, in some embodiments, telecommunication network 1402 includes one or more Open-RAN (ORAN) network nodes. An ORAN network node is a node in telecommunication network 1402 that supports an ORAN specification (e.g., a specification published by the O-RAN Alliance, or any similar organization) and may operate alone or together with other nodes to implement one or more functionalities of any node in telecommunication network 1402, including one or more network nodes 1410 and / or core network nodes 1408.

[0236] Examples of an ORAN network node include an open radio unit (O-RU), an open distributed unit (O-DU), an open central unit (O-CU), including an O-CU control plane (O-CU- CP) or an O-CU user plane (O-CU-UP), a RAN intelligent controller (near-real time or non-real time) hosting software or software plug-ins, such as a near-real time control application (e.g., xApp) or a non-real time control application (e.g., rApp), or any combination thereof (the adjective “open” designating support of an ORAN specification). The network node may support a specification by, for example, supporting an interface defined by the ORAN specification, such as an Al, Fl, Wl, El, E2, X2, Xn interface, an open fronthaul user plane interface, or an open fronthaul management plane interface. Moreover, an ORAN access node may be a logical node in a physical node. Furthermore, an ORAN network node may be implemented in a virtualization environment (described further below) in which one or more network functions are virtualized. For example, the virtualization environment may include an O-Cloud computing platform orchestrated by a Service Management and Orchestration Framework via an 0-2 interface defined by the 0-RAN Alliance or comparable technologies. Network nodes 1410 facilitate direct or indirect connection of UEs, such as by connecting UEs 1412a-d (one or more of which may be generally referred to as UEs 1412) to core network 1406 over one or more wireless connections.

[0237] Example wireless communications over a wireless connection include transmitting and / or receiving wireless signals using electromagnetic waves, radio waves, infrared waves, and / or other types of signals suitable for conveying information without the use of wires, cables, or other material conductors. Moreover, in different embodiments, communication system 1400 may include any number of wired or wireless networks, network nodes, UEs, and / or any other components or systems that may facilitate or participate in the communication of data and / or signals whether via wired or wireless connections. Communication system 1400 may include and / or interface with any type of communication, telecommunication, data, cellular, radio network, and / or other similar type of system.

[0238] UEs 1412 may be any of a wide variety of communication devices, including wireless devices arranged, configured, and / or operable to communicate wirelessly with network nodes 1410 and other communication devices. Similarly, network nodes 1410 are arranged, capable, configured, and / or operable to communicate directly or indirectly with UEs 1412 and / or with other network nodes or equipment in telecommunication network 1402 to enable and / or provide network access, such as wireless network access, and / or to perform other functions, such as administration in telecommunication network 1402.

[0239] In the depicted example, core network 1406 connects network nodes 1410 to one or more hosts, such as host 1416. These connections may be direct or indirect via one or more intermediary networks or devices. In other examples, network nodes may be directly coupled to hosts. Core network 1406 includes one or more core network nodes (e.g., 1408) that are structured with hardware and software components. Features of these components may be substantially similar to those described with respect to the UEs, network nodes, and / or hosts, such that the descriptions thereof are generally applicable to the corresponding components of core network node 1408. Example core network nodes include functions of one or more of a Mobile Switching Center (MSC), Mobility Management Entity (MME), Home Subscriber Server (HSS), Access and Mobility Management Function (AMF), Session Management Function (SMF), Authentication Server Function (AUSF), Subscription Identifier De-concealing function (SIDF), Unified Data Management (UDM), Security Edge Protection Proxy (SEPP), Network Exposure Function (NEF), and / or a User Plane Function (UPF).

[0240] Host 1416 may be under the ownership or control of a service provider other than an operator or provider of access network 1404 and / or telecommunication network 1402, and may be operated by the service provider or on behalf of the service provider. Host 1416 may host a variety of applications to provide one or more service. Examples of such applications include live and pre-recorded audio / video content, data collection services such as retrieving and compiling data on various ambient conditions detected by a plurality of UEs, analytics functionality, social media, functions for controlling or otherwise interacting with remote devices, functions for an alarm and surveillance center, or any other such function performed by a server.

[0241] As a whole, communication system 1400 of Figure 14 enables connectivity between the UEs, network nodes, and hosts. In that sense, the communication system may be configured to operate according to predefined rules or procedures, such as specific standards that include, but are not limited to: Global System for Mobile Communications (GSM); Universal Mobile Telecommunications System (UMTS); Long Term Evolution (LTE), and / or other suitable 2G, 3G, 4G, 5G standards, or any applicable future generation standard (e.g., 6G); wireless local area network (WLAN) standards, such as the Institute of Electrical and Electronics Engineers (IEEE) 802.11 standards (WiFi); and / or any other appropriate wireless communication standard, such as the Worldwide Interoperability for Microwave Access (WiMax), Bluetooth, Z-Wave, Near Field Communication (NFC) ZigBee, LiFi, and / or any low-power wide-area network (LPWAN) standards such as LoRa and Sigfox.

[0242] In some examples, telecommunication network 1402 is a cellular network that implements 3 GPP standardized features. Accordingly, telecommunication network 1402 may support network slicing to provide different logical networks to different devices that are connected to telecommunication network 1402. For example, telecommunication network 1402 may provide Ultra Reliable Low Latency Communication (URLLC) services to some UEs, while providing Enhanced Mobile Broadband (eMBB) services to other UEs, and / or Massive Machine Type Communication (mMTC) / Massive loT services to yet further UEs.

[0243] In some examples, UEs 1412 are configured to transmit and / or receive information without direct human interaction. For instance, a UE may be designed to transmit information to access network 1404 on a predetermined schedule, when triggered by an internal or external event, or in response to requests from access network 1404. Additionally, a UE may be configured for operating in single- or multi-RAT or multi-standard mode. For example, a UE may operate with any one or combination of Wi-Fi, NR (New Radio) and LTE, i.e. being configured for multi-radio dual connectivity (MR-DC), such as E-UTRAN (Evolved-UMTS Terrestrial Radio Access Network) New Radio - Dual Connectivity (EN-DC).

[0244] In the example, hub 1414 communicates with access network 1404 to facilitate indirect communication between one or more UEs (e.g., 1412c and / or 1412d) and network nodes (e.g., 1410b). In some examples, hub 1414 may be a controller, router, content source and analytics, or any of the other communication devices described herein regarding UEs. For example, hub 1414 may be a broadband router enabling access to core network 1406 for the UEs. As another example, hub 1414 may be a controller that sends commands or instructions to one or more actuators in the UEs. Commands or instructions may be received from the UEs, network nodes 1410, or by executable code, script, process, or other instructions in hub 1414. As another example, hub 1414 may be a data collector that acts as temporary storage for UE data and, in some embodiments, may perform analysis or other processing of the data. As another example, hub 1414 may be a content source. For example, for a UE that is a VR headset, display, loudspeaker or other media delivery device, hub 1414 may retrieve VR assets, video, audio, or other media or data related to sensory information via a network node, which hub 1414 then provides to the UE either directly, after performing local processing, and / or after adding additional local content. In still another example, hub 1414 acts as a proxy server or orchestrator for the UEs, in particular if one or more of the UEs are low energy loT devices.

[0245] Hub 1414 may have a constant / persistent or intermittent connection to network node 1410b. Hub 1414 may also allow for a different communication scheme and / or schedule between hub 1414 and UEs (e.g., 1412c and / or 1412d), and between hub 1414 and core network 1406. In other examples, hub 1414 is connected to core network 1406 and / or one or more UEs via a wired connection. Moreover, hub 1414 may be configured to connect to an M2M service provider over access network 1404 and / or to another UE over a direct connection. In some scenarios, UEs may establish a wireless connection with network nodes 1410 while still connected via hub 1414 via a wired or wireless connection. In some embodiments, hub 1414 may be a dedicated hub - that is, a hub whose primary function is to route communications to / from the UEs from / to network node 1410b. In other embodiments, hub 1414 may be a non-dedicated hub - that is, a device which is capable of operating to route communications between the UEs and network node 1410b, but which is additionally capable of operating as a communication start and / or end point for certain data channels. In some embodiments, any of network nodes 1410 may be configured to perform operations attributed to a RAN node in various embodiments described above, including the exemplary method shown in Figure 13. In some embodiments, any of UEs 1412 may be configured to perform operations attributed to a UE in various embodiments described above, including the exemplary method shown in Figure 12.

[0246] Figure 15 shows a UE 1500 in accordance with some embodiments. Examples of a UE include, but are not limited to, a smart phone, mobile phone, cell phone, voice over IP (VoIP) phone, wireless local loop phone, desktop computer, personal digital assistant (PDA), wireless cameras, gaming console or device, music storage device, playback appliance, wearable terminal device, wireless endpoint, mobile station, tablet, laptop, laptop-embedded equipment (LEE), laptop-mounted equipment (LME), smart device, wireless customer-premise equipment (CPE), vehicle, vehicle-mounted or vehicle embedded / integrated wireless device, etc. Other examples include any UE identified by 3 GPP, including a narrow band internet of things (NB-IoT) UE, a machine type communication (MTC) UE, and / or an enhanced MTC (eMTC) UE.

[0247] A UE may support device-to-device (D2D) communication, for example by implementing a 3GPP standard for sidelink communication, Dedicated Short-Range Communication (DSRC), vehicle-to-vehicle (V2V), vehicle-to-infrastructure (V2I), or vehicle-to-everything (V2X). In other examples, a UE may not necessarily have a user in the sense of a human user who owns and / or operates the relevant device. Instead, a UE may represent a device that is intended for sale to, or operation by, a human user but which may not, or which may not initially, be associated with a specific human user (e.g., a smart sprinkler controller). Alternatively, a UE may represent a device that is not intended for sale to, or operation by, an end user but which may be associated with or operated for the benefit of a user (e.g., a smart power meter).

[0248] UE 1500 includes processing circuitry 1502 that is operatively coupled via a bus 1504 to an input / output interface 1506, a power source 1508, a memory 1510, a communication interface 1512, and / or any other component, or any combination thereof. Certain UEs may utilize all or a subset of the components shown in Figure 15. The level of integration between the components may vary from one UE to another UE. Further, certain UEs may contain multiple instances of a component, such as multiple processors, memories, transceivers, transmitters, receivers, etc.

[0249] Processing circuitry 1502 is configured to process instructions and data and may be configured to implement any sequential state machine operative to execute instructions stored as machine-readable computer programs in memory 1510. Processing circuitry 1502 may be implemented as one or more hardware-implemented state machines (e.g., in discrete logic, field- programmable gate arrays (FPGAs), application specific integrated circuits (ASICs), etc.); programmable logic together with appropriate firmware; one or more stored computer programs, general -purpose processors, such as a microprocessor or digital signal processor (DSP), together with appropriate software; or any combination of the above. For example, processing circuitry 1502 may include multiple central processing units (CPUs).

[0250] In the example, input / output interface 1506 may be configured to provide an interface or interfaces to an input device, output device, or one or more input and / or output devices. Examples of an output device include a speaker, a sound card, a video card, a display, a monitor, a printer, an actuator, an emitter, a smartcard, another output device, or any combination thereof. An input device may allow a user to capture information into UE 1500. Examples of an input device include a touch-sensitive or presence-sensitive display, a camera (e.g., a digital camera, a digital video camera, a web camera, etc.), a microphone, a sensor, a mouse, a trackball, a directional pad, a trackpad, a scroll wheel, a smartcard, and the like. The presence-sensitive display may include a capacitive or resistive touch sensor to sense input from a user. A sensor may be, for instance, an accelerometer, a gyroscope, a tilt sensor, a force sensor, a magnetometer, an optical sensor, a proximity sensor, a biometric sensor, etc., or any combination thereof. An output device may use the same type of interface port as an input device. For example, a Universal Serial Bus (USB) port may be used to provide an input device and an output device.

[0251] In some embodiments, power source 1508 is structured as a battery or battery pack. Other types of power sources, such as an external power source (e.g., an electricity outlet), photovoltaic device, or power cell, may be used. Power source 1508 may further include power circuitry for delivering power from power source 1508 itself, and / or an external power source, to the various parts of UE 1500 via input circuitry or an interface such as an electrical power cable. Delivering power may be, for example, for charging power source 1508. Power circuitry may perform any formatting, converting, or other modification to the power from power source 1508 to make the power suitable for the respective components of UE 1500 to which power is supplied.

[0252] Memory 1510 may be or be configured to include memory such as random access memory (RAM), read-only memory (ROM), programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), magnetic disks, optical disks, hard disks, removable cartridges, flash drives, and so forth. In one example, memory 1510 includes one or more application programs 1514, such as an operating system, web browser application, a widget, gadget engine, or other application, and corresponding data 1516. Memory 1510 may store, for use by UE 1500, any of a variety of various operating systems or combinations of operating systems.

[0253] Memory 1510 may be configured to include a number of physical drive units, such as redundant array of independent disks (RAID), flash memory, USB flash drive, external hard disk drive, thumb drive, pen drive, key drive, high-density digital versatile disc (HD-DVD) optical disc drive, internal hard disk drive, Blu-Ray optical disc drive, holographic digital data storage (HDDS) optical disc drive, external mini-dual in-line memory module (DIMM), synchronous dynamic random access memory (SDRAM), external micro-DIMM SDRAM, smartcard memory such as tamper resistant module in the form of a universal integrated circuit card (UICC) including one or more subscriber identity modules (SIMs), such as a USIM and / or ISIM, other memory, or any combination thereof. The UICC may for example be an embedded UICC (eUICC), integrated UICC (iUICC) or a removable UICC commonly known as ‘SIM card.’ Memory 1510 may allow UE 1500 to access instructions, application programs and the like, stored on transitory or non- transitory memory media, to off-load data, or to upload data. An article of manufacture, such as one utilizing a communication system may be tangibly embodied as or in memory 1510, which may be or comprise a device-readable storage medium.

[0254] Processing circuitry 1502 may be configured to communicate with an access network or other network using communication interface 1512. Communication interface 1512 may comprise one or more communication subsystems and may include or be communicatively coupled to an antenna 1522. Communication interface 1512 may include one or more transceivers used to communicate, such as by communicating with one or more remote transceivers of another device capable of wireless communication (e.g., another UE or a network node in an access network). Each transceiver may include a transmitter 1518 and / or a receiver 1520 appropriate to provide network communications (e.g., optical, electrical, frequency allocations, and so forth). Moreover, transmitter 1518 and receiver 1520 may be coupled to one or more antennas (e.g., antenna 1522) and may share circuit components, software, or firmware, or alternatively be implemented separately.

[0255] In the illustrated embodiment, communication functions of communication interface 1512 may include cellular communication, Wi-Fi communication, LPWAN communication, data communication, voice communication, multimedia communication, short-range communications such as Bluetooth, near-field communication, location-based communication such as the use of the global positioning system (GPS) to determine a location, another like communication function, or any combination thereof. Communications may be implemented in according to one or more communication protocols and / or standards, such as IEEE 802.11, Code Division Multiplexing Access (CDMA), Wideband Code Division Multiple Access (WCDMA), GSM, LTE, New Radio (NR), UMTS, WiMax, Ethernet, transmission control protocol / internet protocol (TCP / IP), synchronous optical networking (SONET), Asynchronous Transfer Mode (ATM), QUIC, Hypertext Transfer Protocol (HTTP), and so forth.

[0256] Regardless of the type of sensor, a UE may provide an output of data captured by its sensors, through its communication interface 1512, via a wireless connection to a network node. Data captured by sensors of a UE can be communicated through a wireless connection to a network node via another UE. The output may be periodic (e.g., once every 15 minutes if it reports the sensed temperature), random (e.g., to even out the load from reporting from several sensors), in response to a triggering event (e.g., when moisture is detected an alert is sent), in response to a request (e.g., a user initiated request), or a continuous stream (e.g., a live video feed of a patient).

[0257] As another example, a UE comprises an actuator, a motor, or a switch, related to a communication interface configured to receive wireless input from a network node via a wireless connection. In response to the received wireless input the states of the actuator, the motor, or the switch may change. For example, the UE may comprise a motor that adjusts the control surfaces or rotors of a drone in flight according to the received input or to a robotic arm performing a medical procedure according to the received input.

[0258] A UE, when in the form of an Internet of Things (loT) device, may be a device for use in one or more application domains, these domains comprising, but not limited to, city wearable technology, extended industrial application and healthcare. Non-limiting examples of such an loT device are a device which is or which is embedded in: a connected refrigerator or freezer, a TV, a connected lighting device, an electricity meter, a robot vacuum cleaner, a voice controlled smart speaker, a home security camera, a motion detector, a thermostat, a smoke detector, a door / window sensor, a flood / moisture sensor, an electrical door lock, a connected doorbell, an air conditioning system like a heat pump, an autonomous vehicle, a surveillance system, a weather monitoring device, a vehicle parking monitoring device, an electric vehicle charging station, a smart watch, a fitness tracker, a head-mounted display for Augmented Reality (AR) or Virtual Reality (VR), a wearable for tactile augmentation or sensory enhancement, a water sprinkler, an animal- or item-tracking device, a sensor for monitoring a plant or animal, an industrial robot, an Unmanned Aerial Vehicle (UAV), and any kind of medical device, like a heart rate monitor or a remote controlled surgical robot. A UE in the form of an loT device comprises circuitry and / or software in dependence of the intended application of the loT device in addition to other components as described in relation to UE 1500 shown in Figure 15.

[0259] As yet another specific example, in an loT scenario, a UE may represent a machine or other device that performs monitoring and / or measurements, and transmits the results of such monitoring and / or measurements to another UE and / or a network node. The UE may in this case be an M2M device, which may in a 3 GPP context be referred to as an MTC device. As one particular example, the UE may implement the 3GPP NB-IoT standard. In other scenarios, a UE may represent a vehicle, such as a car, a bus, a truck, a ship and an airplane, or other equipment that is capable of monitoring and / or reporting on its operational status or other functions associated with its operation. In practice, any number of UEs may be used together with respect to a single use case. For example, a first UE might be or be integrated in a drone and provide the drone’s speed information (obtained through a speed sensor) to a second UE that is a remote controller operating the drone. When the user makes changes from the remote controller, the first UE may adjust the throttle on the drone (e.g. by controlling an actuator) to increase or decrease the drone’s speed. The first and / or the second UE can also include more than one of the functionalities described above. For example, a UE might comprise the sensor and the actuator, and handle communication of data for both the speed sensor and the actuators.

[0260] In some embodiments, UE 1500 may be configured to perform operations attributed to a UE in various embodiments described above, including the exemplary method shown in Figure 12.

[0261] Figure 16 shows a network node 1600 in accordance with some embodiments. Examples of network nodes include, but are not limited to, access points (APs) (e.g., radio access points), base stations (e.g., radio base stations, Node Bs, eNBs, gNBs), and 0-RAN nodes or components of an 0-RAN node (e g., 0-RU, 0-DU, O-CU).

[0262] Base stations may be categorized based on the amount of coverage they provide (or, stated differently, their transmit power level) and so, depending on the provided amount of coverage, may be referred to as femto base stations, pico base stations, micro base stations, or macro base stations. A base station may be a relay node or a relay donor node controlling a relay. A network node may also include one or more (or all) parts of a distributed radio base station such as centralized digital units, distributed units (e.g., in an 0-RAN access node) and / or remote radio units (RRUs), sometimes referred to as Remote Radio Heads (RRHs). Such remote radio units may or may not be integrated with an antenna as an antenna integrated radio. Parts of a distributed radio base station may also be referred to as nodes in a distributed antenna system (DAS).

[0263] Other examples of network nodes include multiple transmission point (multi-TRP) 5G access nodes, multi-standard radio (MSR) equipment such as MSR BSs, network controllers such as radio network controllers (RNCs) or base station controllers (BSCs), base transceiver stations (BTSs), transmission points, transmission nodes, multi-cell / multicast coordination entities (MCEs), Operation and Maintenance (O&M) nodes, Operations Support System (OSS) nodes, Self-Organizing Network (SON) nodes, positioning nodes (e.g., Evolved Serving Mobile Location Centers (E-SMLCs)), and / or Minimization of Drive Tests (MDTs).

[0264] Network node 1600 includes processing circuitry 1602, memory 1604, communication interface 1606, and power source 1608. Network node 1600 may be composed of multiple physically separate components (e.g., a NodeB component and a RNC component, or a BTS component and a BSC component, etc.), which may each have their own respective components. In certain scenarios in which network node 1600 comprises multiple separate components (e.g., BTS and BSC components), one or more of the separate components may be shared among several network nodes. For example, a single RNC may control multiple NodeBs. In such a scenario, each unique NodeB and RNC pair, may in some instances be considered a single separate network node. In some embodiments, network node 1600 may be configured to support multiple radio access technologies (RATs). In such embodiments, some components may be duplicated (e.g., separate memory 1604 for different RATs) and some components may be reused (e.g., a same antenna 1610 may be shared by different RATs). Network node 1600 may also include multiple sets of the various illustrated components for different wireless technologies integrated into network node 1600, for example GSM, WCDMA, LTE, NR, WiFi, Zigbee, Z-wave, LoRaWAN, Radio Frequency Identification (RFID) or Bluetooth wireless technologies. These wireless technologies may be integrated into the same or different chip or set of chips and other components within network node 1600.

[0265] Processing circuitry 1602 may comprise a combination of one or more of a microprocessor, controller, microcontroller, central processing unit, digital signal processor, application-specific integrated circuit, field programmable gate array, or any other suitable computing device, resource, or combination of hardware, software and / or encoded logic operable to provide, either alone or in conjunction with other network node 1600 components, such as memory 1604, to provide network node 1600 functionality.

[0266] In some embodiments, processing circuitry 1602 includes a system on a chip (SOC). In some embodiments, processing circuitry 1602 includes one or more of radio frequency (RF) transceiver circuitry 1612 and baseband processing circuitry 1614. In some embodiments, RF transceiver circuitry 1612 and baseband processing circuitry 1614 may be on separate chips (or sets of chips), boards, or units, such as radio units and digital units. In alternative embodiments, part or all of RF transceiver circuitry 1612 and baseband processing circuitry 1614 may be on the same chip or set of chips, boards, or units.

[0267] Memory 1604 may comprise any form of volatile or non-volatile computer-readable memory including, without limitation, persistent storage, solid-state memory, remotely mounted memory, magnetic media, optical media, random access memory (RAM), read-only memory (ROM), mass storage media (for example, a hard disk), removable storage media (for example, a flash drive, a Compact Disk (CD) or a Digital Video Disk (DVD)), and / or any other volatile or non-volatile, non-transitory device-readable and / or computer-executable memory devices that store information, data, and / or instructions that may be used by processing circuitry 1602. Memory 1604 may store any suitable instructions, data, or information, including a computer program, software, an application including one or more of logic, rules, code, tables, and / or other instructions (collected denoted computer program 1604a, which may be in the form of a computer program product) capable of being executed by processing circuitry 1602 and utilized by network node 1600. Memory 1604 may be used to store any calculations made by processing circuitry 1602 and / or any data received via communication interface 1606. In some embodiments, processing circuitry 1602 and memory 1604 is integrated.

[0268] Communication interface 1606 is used in wired or wireless communication of signaling and / or data between a network node, access network, and / or UE. As illustrated, communication interface 1606 comprises port(s) / terminal(s) 1616 to send and receive data, for example to and from a network over a wired connection. Communication interface 1606 also includes radio frontend circuitry 1618 that may be coupled to, or in certain embodiments a part of, antenna 1610. Radio front-end circuitry 1618 comprises filters 1620 and amplifiers 1622. Radio front-end circuitry 1618 may be connected to an antenna 1610 and processing circuitry 1602. The radio front-end circuitry may be configured to condition signals communicated between antenna 1610 and processing circuitry 1602. Radio front-end circuitry 1618 may receive digital data that is to be sent out to other network nodes or UEs via a wireless connection. Radio front-end circuitry 1618 may convert the digital data into a radio signal having the appropriate channel and bandwidth parameters using a combination of filters 1620 and / or amplifiers 1622. The radio signal may then be transmitted via antenna 1610. Similarly, when receiving data, antenna 1610 may collect radio signals which are then converted into digital data by radio front-end circuitry 1618. The digital data may be passed to processing circuitry 1602. In other embodiments, the communication interface may comprise different components and / or different combinations of components.

[0269] In certain alternative embodiments, network node 1600 does not include separate radio front-end circuitry 1618, instead, processing circuitry 1602 includes radio front-end circuitry and is connected to antenna 1610. Similarly, in some embodiments, all or some of RF transceiver circuitry 1612 is part of communication interface 1606. In still other embodiments, communication interface 1606 includes one or more ports or terminals 1616, radio front-end circuitry 1618, and RF transceiver circuitry 1612, as part of a radio unit (not shown), and communication interface 1606 communicates with baseband processing circuitry 1614, which is part of a digital unit (not shown).

[0270] Antenna 1610 may include one or more antennas, or antenna arrays, configured to send and / or receive wireless signals. Antenna 1610 may be coupled to radio front-end circuitry 1618 and may be any type of antenna capable of transmitting and receiving data and / or signals wirelessly. In certain embodiments, antenna 1610 is separate from network node 1600 and connectable to network node 1600 through an interface or port. Antenna 1610, communication interface 1606, and / or processing circuitry 1602 may be configured to perform any receiving operations and / or certain obtaining operations described herein as being performed by the network node. Any information, data and / or signals may be received from a UE, another network node and / or any other network equipment. Similarly, antenna 1610, communication interface 1606, and / or processing circuitry 1602 may be configured to perform any transmitting operations described herein as being performed by the network node. Any information, data and / or signals may be transmitted to a UE, another network node and / or any other network equipment.

[0271] Power source 1608 provides power to the various components of network node 1600 in a form suitable for the respective components (e.g., at a voltage and current level needed for each respective component). Power source 1608 may further comprise, or be coupled to, power management circuitry to supply the components of network node 1600 with power for performing the functionality described herein. For example, network node 1600 may be connectable to an external power source (e.g., the power grid, an electricity outlet) via an input circuitry or interface such as an electrical cable, whereby the external power source supplies power to power circuitry of power source 1608. As a further example, power source 1608 may comprise a source of power in the form of a battery or battery pack which is connected to, or integrated in, power circuitry. The battery may provide backup power should the external power source fail.

[0272] Embodiments of network node 1600 may include additional components beyond those shown in Figure 16 for providing certain aspects of the network node’s functionality, including any of the functionality described herein and / or any functionality necessary to support the subject matter described herein. For example, network node 1600 may include user interface equipment to allow input of information into network node 1600 and to allow output of information from network node 1600. This may allow a user to perform diagnostic, maintenance, repair, and other administrative functions for network node 1600.

[0273] In some embodiments, network node 1600 may be configured to perform operations attributed to a RAN node in various embodiments described above, including the exemplary method shown in Figure 13.

[0274] Figure 17 is a block diagram illustrating a virtualization environment 1700 in which functions implemented by some embodiments may be virtualized. In the present context, virtualizing means creating virtual versions of apparatuses or devices which may include virtualizing hardware platforms, storage devices and networking resources. As used herein, virtualization can be applied to any device described herein, or components thereof, and relates to an implementation in which at least a portion of the functionality is implemented as one or more virtual components. Some or all of the functions described herein may be implemented as virtual components executed by one or more virtual machines (VMs) implemented in one or more virtual environments 1700 hosted by one or more of hardware nodes, such as a hardware computing device that operates as a network node, UE, core network node, or host. Further, in embodiments in which the virtual node does not require radio connectivity (e.g., a core network node or host), then the node may be entirely virtualized. In some embodiments, the virtualization environment 1700 includes components defined by the O-RAN Alliance, such as an O-Cloud environment orchestrated by a Service Management and Orchestration Framework via an 0-2 interface.

[0275] Applications 1702 (which may alternatively be called software instances, virtual appliances, network functions, virtual nodes, virtual network functions, etc.) are run in the virtualization environment 1700 to implement some of the features, functions, and / or benefits of some of the embodiments disclosed herein. For example, one or more virtual nodes 1702 may be configured to perform operations attributed to a RAN node in various embodiments described above, including the exemplary method shown in Figure 13.

[0276] Hardware 1704 includes processing circuitry, memory that stores software and / or instructions (collected denoted computer program 1704a, which may be in the form of a computer program product) executable by hardware processing circuitry, and / or other hardware devices as described herein, such as a network interface, input / output interface, and so forth. Software may be executed by the processing circuitry to instantiate one or more virtualization layers 1706 (also referred to as hypervisors or virtual machine monitors (VMMs)), provide VMs 1708a and 1708b (one or more of which may be generally referred to as VMs 1708), and / or perform any of the functions, features and / or benefits described in relation with some embodiments described herein. Virtualization layer 1706 may present a virtual operating platform that appears like networking hardware to the VMs 1708.

[0277] VMs 1708 comprise virtual processing, virtual memory, virtual networking or interface and virtual storage, and may be run by a corresponding virtualization layer 1706. Different embodiments of the instance of a virtual appliance 1702 may be implemented on one or more of VMs 1708, and the implementations may be made in different ways. Virtualization of the hardware is in some contexts referred to as network function virtualization (NFV). NFV may be used to consolidate many network equipment types onto industry standard high volume server hardware, physical switches, and physical storage, which can be located in data centers, and customer premise equipment.

[0278] In the context of NFV, each VM 1708 may be a software implementation of a physical machine that runs programs as if they were executing on a physical, non-virtualized machine. Each VM 1708, and that part of hardware 1704 that executes that VM, be it hardware dedicated to that VM and / or hardware shared by that VM with others of the VMs, forms separate virtual network elements. Still in the context of NFV, a virtual network function is responsible for handling specific network functions that run in one or more VMs 1708 on top of the hardware 1704 and corresponds to the application 1702.

[0279] Hardware 1704 may be implemented in a standalone network node with generic or specific components. Hardware 1704 may implement some functions via virtualization. Alternatively, hardware 1704 may be part of a larger cluster of hardware (e.g. such as in a data center or CPE) where many hardware nodes work together and are managed via management and orchestration function 1710, which, among others, oversees lifecycle management of applications 1702. In some embodiments, hardware 1704 is coupled to one or more radio units that each include one or more transmitters and one or more receivers that may be coupled to one or more antennas. Radio units may communicate directly with other hardware nodes via one or more appropriate network interfaces and may be used in combination with the virtual components to provide a virtual node with radio capabilities, such as a radio access node or a base station. In some embodiments, some signaling can be provided with the use of a control system 1712 which may alternatively be used for communication between hardware nodes and radio units.

[0280] The foregoing merely illustrates the principles of the disclosure. Various modifications and alterations to the described embodiments will be apparent to those skilled in the art in view of the teachings herein. It will thus be appreciated that those skilled in the art will be able to devise numerous systems, arrangements, and procedures that, although not explicitly shown or described herein, embody the principles of the disclosure and can be thus within the spirit and scope of the disclosure. Various embodiments can be used together with one another, as well as interchangeably therewith, as should be understood by those having ordinary skill in the art.

[0281] The term unit, as used herein, can have conventional meaning in the field of electronics, electrical devices and / or electronic devices and can include, for example, electrical and / or electronic circuitry, devices, modules, processors, memories, logic solid state and / or discrete devices, computer programs or instructions for carrying out respective tasks, procedures, computations, outputs, and / or displaying functions, and so on, as such as those that are described herein.

[0282] Any appropriate steps, methods, features, functions, or benefits disclosed herein may be performed through one or more functional units or modules of one or more virtual apparatuses. Each virtual apparatus may comprise a number of these functional units. These functional units may be implemented via processing circuitry, which may include one or more microprocessor or microcontrollers, as well as other digital hardware, which may include Digital Signal Processor (DSPs), special-purpose digital logic, and the like. The processing circuitry may be configured to execute program code stored in memory, which may include one or several types of memory such as Read Only Memory (ROM), Random Access Memory (RAM), cache memory, flash memory devices, optical storage devices, etc. Program code stored in memory includes program instructions for executing one or more telecommunications and / or data communications protocols as well as instructions for carrying out one or more of the techniques described herein. In some implementations, the processing circuitry may be used to cause the respective functional unit to perform corresponding functions according to one or more embodiments of the present disclosure.

[0283] As described herein, device and / or apparatus can be represented by a semiconductor chip, a chipset, or a (hardware) module comprising such chip or chipset; this, however, does not exclude the possibility that a functionality of a device or apparatus, instead of being hardware implemented, be implemented as a software module such as a computer program or a computer program product comprising executable software code portions for execution or being run on a processor. Furthermore, functionality of a device or apparatus can be implemented by any combination of hardware and software. A device or apparatus can also be regarded as an assembly of multiple devices and / or apparatuses, whether functionally in cooperation with or independently of each other. Moreover, devices and apparatuses can be implemented in a distributed fashion throughout a system, so long as the functionality of the device or apparatus is preserved. Such and similar principles are considered as known to a skilled person.

[0284] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. It will be further understood that terms used herein should be interpreted as having a meaning that is consistent with their meaning in the context of this specification and the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

[0285] In addition, certain terms used in the present disclosure, including the specification and drawings, can be used synonymously in certain instances (e.g., “data” and “information”). It should be understood, that although these terms (and / or other terms that can be synonymous to one another) can be used synonymously herein, there can be instances when such words can be intended to not be used synonymously.

[0286] Embodiments of the techniques and apparatus described herein also include, but are not limited to, the following enumerated examples:

[0287] Al . A method for a user equipment (UE) configured to transmit application data to a radio access network (RAN) node, the method comprising: buffering data generated by an application hosted by the UE, wherein: the buffered data comprises a plurality of sets of protocol data units (PDUs), and each buffered PDU set is associated a logical channel group (LCG), at least one importance level, and a packet data convergence protocol (PDCP) discard timer; and transmitting to the RAN node a message that indicates the following: at least one LCG associated with the buffered PDU sets; and for each indicated LCG, delay information and one or more importance levels associated with the buffered PDU sets for the indicated LCG.

[0288] A2. The method of embodiment Al, wherein: the message includes an initial octet of bits, with the bits of the initial octet being associated with respective ones of a plurality of LCGs; and each bit in the initial octet indicates whether the message indicates the delay information and the one or more importance levels associated with the buffered PDU sets for the associated LCG.

[0289] A3. The method of any of embodiments A1-A2, wherein the delay information includes the following: a shortest remaining time on PDCP discard timers associated with the buffered PDU sets for the indicated LCG, and an amount of delay-critical data in the buffered PDU sets for the indicated LCG.

[0290] A4. The method of embodiment A3, wherein for each LCG indicated by the initial octet, the message includes a pair of adjacent octets arranged as: a first octet that includes indications of the one or more importance levels and the shortest remaining time on PDCP discard timers associated with the buffered PDU sets for the indicated LCG; and a second octet that indicates the amount of delay-critical data in the buffered PDU sets for the indicated LCG.

[0291] A4a. The method of embodiment A4, wherein for each LCG indicated by the initial octet, the first octet for the LCG indicates one of the following: a single importance level of the buffered PDU sets for the LCG; multiple different importance levels of the buffered PDU sets for the LCG; or whether the message also includes a subsequent pair of adjacent octets for the LCG. A4b. The method of embodiment A4a, wherein the indicated single importance level is one of the following a highest importance level of the buffered PDU sets for the LCG; a lowest importance level of the buffered PDU sets for the LCG; or an importance level having the most buffered data in the buffered PDU sets for the LCG;

[0292] A4c. The method of any of embodiments A4a-A4b, wherein when first octet for the LCG indicates the single importance level, the second octet indicates the amount of delay-critical data of the single importance level in the buffered PDU sets for the LCG.

[0293] A4d. The method of any of embodiments A4a-A4c, wherein the first octet for the LCG includes a bit field of a plurality of bits, and respective values of the bit field indicate one of the following: respective one or more importance levels of the buffered PDU sets for the LCG; or respective portions of the buffered PDU sets for the LCG that are of highest importance level.

[0294] A4e. The method of embodiment A4d, wherein the plurality of bits include a first bit that is configurable by the RAN node to be used as either of the following: a buffer size mapping table indicator bit, or an importance level indicator bit.

[0295] A4f. The method of embodiment A4a, wherein when the first octet for the LCG indicates that the message also includes a subsequent pair of adjacent octets for the LCG: the first octet indicates the shortest remaining time on PDCP discard timers associated with the buffered PDU sets of a highest importance level for the LCG; and the second octet indicates the amount of delay-critical data of the highest importance level in the buffered PDU sets for the LCG.

[0296] A4g. The method of any of embodiments A4a and A4f, wherein when the first octet for the LCG indicates that the message also includes a subsequent pair of adjacent octets for the LCG, the subsequent pair of octets is arranged as follows: a third octet that indicates the following: whether the message also includes another subsequent pair of adjacent octets for the LCG, and the shortest remaining time on PDCP discard timers associated with the buffered PDU sets of a next highest importance level for the LCG; and a fourth octet that indicates an amount of delay-critical data of the next highest importance level in the buffered PDU sets for the indicated LCG.

[0297] A5. The method of embodiment A3, wherein for each LCG indicated by the initial octet, the message includes the following: one or more pairs of adjacent octets for the LCG, with each pair arranged as: a first octet that indicates the shortest remaining time on PDCP discard timers associated with the buffered PDU sets for the indicated LCG, and a second octet that indicates the amount of delay-critical data in the buffered PDU sets for the indicated LCG; and a bit field in a further octet located in the message after the initial octet but before the one or more pairs of adjacent octets for the LCG, wherein the bit field indicates the one or more importance levels for the indicated LCG.

[0298] A5a. The method of embodiment A5, wherein the bit field is the entire further octet, such that for each LCG indicated by the initial octet, the message includes a corresponding further octet located after the initial octet but before any pairs of adjacent octets for the indicated LCGs.

[0299] A5b. The method of any of embodiments A5-A5a, wherein: when the bit field in the further octet indicates a plurality of importance levels for the LCG, the message includes a corresponding plurality of pairs of adjacent octets for the LCG; each first octet indicates the shortest remaining time on PDCP discard timers associated with the buffered PDU set of the corresponding importance level for the LCG, and each second octet indicates the amount of delay-critical data in the buffered PDU sets of the corresponding importance level for the indicated LCG.

[0300] A5c. The method of embodiment A5b, wherein the plurality of pairs of adjacent octets for the LCG are adjacent in the message, and are arranged in increasing or decreasing order of corresponding importance level.

[0301] A6. The method of embodiment A3, wherein for each LCG indicated by the initial octet, the first octet for the LCG includes an importance level indicator bit, wherein the importance level indicator bits for all LCGs indicated by the initial octet are logically combined into a bit field that indicates one or more importance levels associated with the buffered PDU sets for the indicated LCGs.

[0302] A6a. The method of embodiment A6, wherein the logically combined bit field indicates one of the following: a percentage or amount of buffered PDU sets for all indicated LCGs, that is high importance or delay-critical; or respective percentages or amounts of buffered PDU sets for the respective indicated LCGs, that is high importance or delay-critical.

[0303] A7. The method of any of embodiments Al-A6a, further comprising receiving from the RAN node a reporting configuration that indicates one or more of the following: which importance levels should be reported for buffered PDU sets; which LCGs with buffered PDU sets should be reported; a threshold for distinguishing between high and low importance levels; reporting format to be used; and a buffer size mapping table to be used for reporting delay information, wherein the message transmitted to the RAN node is in accordance with the reporting configuration.

[0304] A8. The method of any of embodiments A1-A7, further comprising: in response to the message, receiving from the RAN node a grant of uplink resources; and transmitting at least a portion of the buffered data to the RAN node, using the granted uplink resources.

[0305] A9. The method of any of embodiments A1-A8, further comprising: in response to the message, receiving from the RAN node a discard configuration indicating one or more of the following: one or more importance levels for which associated buffered PDU sets may be discarded, and one or more importance levels for which associated buffered PDU sets should not be discarded; and selectively discarding the buffered PDU sets in accordance with the discard configuration. A10. The method of any of embodiments A1-A9, wherein the message is a delay status report (DSR) medium access control (MAC) control element (CE).

[0306] Al 1. The method of any of embodiments A1-A10, wherein the application is an extended reality (XR) application and the data generated by the application has a bounded latency requirement.

[0307] Bl. A method for a radio access network (RAN) node configured to receive application data from a user equipment (UE), the method comprising: receiving from the UE a message pertaining to buffered data generated by an application hosted by the UE, wherein: the buffered data comprises a plurality of sets of protocol data units (PDUs); each buffered PDU set is associated a logical channel group (LCG), at least one importance level, and a packet data convergence protocol (PDCP) discard timer; and the message indicates the following: at least one LCG associated with buffered PDU sets; and for each indicated LCG, delay information and one or more importance levels associated with the buffered PDU sets for the indicated LCG.

[0308] B2. The method of embodiment Bl, wherein: the message includes an initial octet of bits, with the bits of the initial octet being associated with respective ones of a plurality of LCGs; and each bit in the initial octet indicates whether the message indicates the delay information and the one or more importance levels associated with the buffered PDU sets for the associated LCG.

[0309] B3. The method of any of embodiments B1-B2, wherein the delay information includes the following: a shortest remaining time on PDCP discard timers associated with the buffered PDU sets for the indicated LCG, and an amount of delay-critical data in the buffered PDU sets for the indicated LCG. B4. The method of embodiment B3, wherein for each LCG indicated by the initial octet, the message includes a pair of adjacent octets arranged as: a first octet that includes indications of the one or more importance levels and the shortest remaining time on PDCP discard timers associated with the buffered PDU sets for the indicated LCG; and a second octet that indicates the amount of delay-critical data in the buffered PDU sets for the indicated LCG.

[0310] B4a. The method of embodiment B4, wherein for each LCG indicated by the initial octet, the first octet for the LCG indicates one of the following: a single importance level of the buffered PDU sets for the LCG; multiple different importance levels of the buffered PDU sets for the LCG; or whether the message also includes a subsequent pair of adjacent octets for the LCG.

[0311] B4b. The method of embodiment B4a, wherein the indicated single importance level is one of the following a highest importance level of the buffered PDU sets for the LCG; a lowest importance level of the buffered PDU sets for the LCG; or an importance level having the most buffered data in the buffered PDU sets for the LCG;

[0312] B4c. The method of any of embodiments B4a-B4b, wherein when first octet for the LCG indicates the single importance level, the second octet indicates the amount of delay-critical data of the single importance level in the buffered PDU sets for the LCG.

[0313] B4d. The method of any of embodiments B4a-B4c, wherein the first octet for the LCG includes a bit field of a plurality of bits, and respective values of the bit field indicate one of the following: respective one or more importance levels of the buffered PDU sets for the LCG; or respective portions of the buffered PDU sets for the LCG that are of highest importance level.

[0314] B4e. The method of embodiment B4d, wherein the plurality of bits include a first bit that is configurable by the RAN node to be used as either of the following: a buffer size mapping table indicator bit, or an importance level indicator bit. B4f. The method of embodiment B4a, wherein when the first octet for the LCG indicates that the message also includes a subsequent pair of adjacent octets for the LCG: the first octet indicates the shortest remaining time on PDCP discard timers associated with the buffered PDU sets of a highest importance level for the LCG; and the second octet indicates the amount of delay-critical data of the highest importance level in the buffered PDU sets for the LCG.

[0315] B4g. The method of any of embodiments B4a and B4f, wherein when the first octet for the LCG indicates that the message also includes a subsequent pair of adjacent octets for the LCG, the subsequent pair of octets is arranged as follows: a third octet that indicates the following: whether the message also includes another subsequent pair of adjacent octets for the LCG, and the shortest remaining time on PDCP discard timers associated with the buffered PDU sets of a next highest importance level for the LCG; and a fourth octet that indicates an amount of delay-critical data of the next highest importance level in the buffered PDU sets for the indicated LCG.

[0316] B5. The method of embodiment B3, wherein for each LCG indicated by the initial octet, the message includes the following: one or more pairs of adjacent octets for the LCG, with each pair arranged as: a first octet that indicates the shortest remaining time on PDCP discard timers associated with the buffered PDU sets for the indicated LCG, and a second octet that indicates the amount of delay-critical data in the buffered PDU sets for the indicated LCG; and a bit field in a further octet located in the message after the initial octet but before the one or more pairs of adjacent octets for the LCG, wherein the bit field indicates the one or more importance levels for the indicated LCG.

[0317] B5a. The method of embodiment B5, wherein the bit field is the entire further octet, such that for each LCG indicated by the initial octet, the message includes a corresponding further octet located after the initial octet but before any pairs of adjacent octets for the indicated LCGs.

[0318] B5b. The method of any of embodiments B5-B5a, wherein: when the bit field in the further octet indicates a plurality of importance levels for the LCG, the message includes a corresponding plurality of pairs of adjacent octets for the LCG; each first octet indicates the shortest remaining time on PDCP discard timers associated with the buffered PDU set of the corresponding importance level for the LCG, and each second octet indicates the amount of delay-critical data in the buffered PDU sets of the corresponding importance level for the indicated LCG.

[0319] B5c. The method of embodiment B5b, wherein the plurality of pairs of adjacent octets for the LCG are adjacent in the message, and are arranged in increasing or decreasing order of corresponding importance level.

[0320] B6. The method of embodiment B3, wherein for each LCG indicated by the initial octet, the first octet for the LCG includes an importance level indicator bit, wherein the importance level indicator bits for all LCGs indicated by the initial octet are logically combined into a bit field that indicates one or more importance levels associated with the buffered PDU sets for the indicated LCGs.

[0321] B6a. The method of embodiment B6, wherein the logically combined bit field indicates one of the following: a percentage or amount of buffered PDU sets for all indicated LCGs, that is high importance or delay-critical; or respective percentages or amounts of buffered PDU sets for the respective indicated LCGs, that is high importance or delay-critical.

[0322] B7. The method of any of embodiments Bl-B6a, further comprising sending to the UE a reporting configuration that indicates one or more of the following: which importance levels should be reported for buffered PDU sets; which LCGs with buffered PDU sets should be reported; a threshold for distinguishing between high and low importance levels; reporting format to be used; and a buffer size mapping table to be used for reporting delay information, wherein the message received from the UE is in accordance with the reporting configuration. B8. The method of any of embodiments B1-B7, further comprising: in response to the message, sending to the UE a grant of uplink resources; and receiving at least a portion of the buffered data from the UE using the granted uplink resources.

[0323] B9. The method of any of embodiments B1-B8, further comprising, in response to the message, sending to the UE a discard configuration indicating one or more of the following: one or more importance levels for which associated buffered PDU sets may be discarded, and one or more importance levels for which associated buffered PDU sets should not be discarded.

[0324] BIO. The method of any of embodiments B1-B9, wherein the message is a delay status report (DSR) medium access control (MAC) control element (CE).

[0325] Bl 1. The method of any of embodiments Bl -BIO, wherein the application is an extended reality (XR) application and the data generated by the application has a bounded latency requirement.

[0326] Cl . A user equipment (UE) configured to transmit application data to a radio access network

[0327] (RAN) node, the UE comprising: communication interface circuitry configured to communicate with the serving cells; and processing circuitry operatively coupled to the communication interface circuitry, whereby the processing circuitry and the communication interface circuitry are configured to perform operations corresponding to any of the methods of embodiments Al -Al 1.

[0328] C2. A user equipment (UE) configured to transmit application data to a radio access network (RAN) node, the UE being further configured to perform operations corresponding to any of the methods of embodiments Al-Al l.

[0329] C3. A non-transitory, computer-readable medium storing computer-executable instructions that, when executed by processing circuitry of a user equipment (UE) configured to transmit application data to a radio access network (RAN) node, configure the UE to perform operations corresponding to any of the methods of embodiments Al -Al 1.

[0330] C4. A computer program product comprising computer-executable instructions that, when executed by processing circuitry of a user equipment (UE) configured to transmit application data to a radio access network (RAN) node, configure the UE to perform operations corresponding to any of the methods of embodiments Al -Al 1.

[0331] DI . A radio access network (RAN) node configured to receive application data from a user equipment (UE), the RAN node comprising: communication interface circuitry configured to communicate with the UE via the serving cells; and processing circuitry operatively coupled to the communication interface circuitry, whereby the processing circuitry and the communication interface circuitry are configured to perform operations corresponding to any of the methods of embodiments B 1 -B 11.

[0332] D2. A radio access network (RAN) node configured to receive application data from a user equipment (UE), the RAN node being further configured to perform operations corresponding to any of the methods of embodiments Bl -Bl 1.

[0333] D3. A non-transitory, computer-readable medium storing computer-executable instructions that, when executed by processing circuitry of a radio access network (RAN) node configured to receive application data from a user equipment (UE), configure the RAN node to perform operations corresponding to any of the methods of embodiments Bl -Bl 1.

[0334] D4. A computer program product comprising computer-executable instructions that, when executed by processing circuitry of a radio access network (RAN) node configured to receive application data from a user equipment (UE), configure the RAN node to perform operations corresponding to any of the methods of embodiments Bl -Bl 1.

Claims

CLAIMS1. A method for a user equipment, UE, configured to transmit application data to a radio access network, RAN, node, the method comprising: buffering (1220) data generated by an application hosted by the UE, wherein: the buffered data comprises a plurality of sets of protocol data units, PDUs; and each buffered PDU set is associated with the following: a logical channel group, LCG; at least one importance level; and a packet data convergence protocol, PDCP, discard timer; and transmitting (1230) to the RAN node a message that indicates the following: at least one LCG associated with the buffered PDU sets; and delay information and one or more importance levels for the buffered PDU sets associated with the indicated at least one LCG.

2. The method of claim 1, wherein the delay information for each indicated LCG includes the following: a shortest remaining time on PDCP discard timers associated with the buffered PDU sets for the indicated LCG, and an amount of delay-critical data in the buffered PDU sets for the indicated LCG.

3. The method of any of claims 1-2, wherein: the message includes an initial octet of bits, with the bits of the initial octet being associated with respective ones of a plurality of LCGs; and the initial octet indicates LCGs, of the plurality of LCGs, for which the message indicates the delay information and the one or more importance levels.

4. The method of claim 3, wherein for each LCG indicated by the initial octet, the message includes a pair of adjacent octets arranged as: a first octet that includes indications of the one or more importance levels and the shortest remaining time on PDCP discard timers associated with the buffered PDU sets for the indicated LCG; and a second octet that indicates the amount of delay-critical data in the buffered PDU sets for the indicated LCG.

5. The method of claim 4, wherein for each LCG indicated by the initial octet, the first octet indicates one of the following: a single importance level of the buffered PDU sets for the indicated LCG; multiple different importance levels of the buffered PDU sets for the indicated LCG; or whether the message also includes a subsequent pair of adjacent octets for the indicated LCG.

6. The method of claim 5, wherein the indicated single importance level is one of the following a highest importance level of the buffered PDU sets for the indicated LCG; a lowest importance level of the buffered PDU sets for the indicated LCG; or an importance level having the most buffered data in the buffered PDU sets for the indicated LCG;7. The method of any of claims 5-6, wherein when first octet indicates the single importance level, the second octet indicates the amount of delay-critical data of the single importance level in the buffered PDU sets for the indicated LCG.

8. The method of any of claims 5-7, wherein the first octet includes a bit field of a plurality of bits, and respective values of the bit field indicate one of the following: respective one or more importance levels of the buffered PDU sets for the indicated LCG; or respective portions of the buffered PDU sets for the indicated LCG that are of highest importance level.

9. The method of claim 8, wherein the plurality of bits include a first bit that is configurable by the RAN node to be used as either of the following: a buffer size mapping table indicator bit, or an importance level indicator bit.

10. The method of claim 5, wherein when the first octet indicates that the message also includes a subsequent pair of adjacent octets: the first octet indicates the shortest remaining time on PDCP discard timers associated with the buffered PDU sets of a highest importance level for the indicated LCG; andthe second octet indicates the amount of delay-critical data of the highest importance level in the buffered PDU sets for the indicated LCG.

11. The method of any of claims 5 and 10, wherein when the first octet indicates that the message also includes a subsequent pair of adjacent octets, the subsequent pair of adjacent octets is arranged as follows: a third octet that indicates the following: whether the message also includes another subsequent pair of adjacent octets for the indicated LCG, and the shortest remaining time on PDCP discard timers associated with the buffered PDU sets of a next highest importance level for the indicated LCG; and a fourth octet that indicates an amount of delay-critical data of the next highest importance level in the buffered PDU sets for the indicated LCG.

12. The method of claim 3, wherein for each LCG indicated by the initial octet, the message includes the following: one or more pairs of adjacent octets for the indicated LCG, with each pair arranged as: a first octet that indicates the shortest remaining time on PDCP discard timers associated with the buffered PDU sets for the indicated LCG, and a second octet that indicates the amount of delay-critical data in the buffered PDU sets for the indicated LCG; and a bit field in a further octet that is after the initial octet but before the one or more pairs of adjacent octets for the indicated LCG, wherein the bit field indicates the one or more importance levels for the indicated LCG.

13. The method of claim 12, wherein the bit field is the entire further octet, such that for each LCG indicated by the initial octet, the message includes a corresponding further octet located after the initial octet but before any pairs of adjacent octets for the LCGs indicated by the initial octet.

14. The method of any of claims 12-13, wherein for each LCG indicated by the initial octet: when the bit field in the further octet indicates a plurality of importance levels for the indicated LCG, the message includes a corresponding plurality of pairs of adjacent octets for the indicated LCG;each first octet indicates the shortest remaining time on PDCP discard timers associated with the buffered PDU set of the corresponding importance level for the indicated LCG, and each second octet indicates the amount of delay-critical data in the buffered PDU sets of the corresponding importance level for the indicated LCG.

15. The method of claim 14, wherein the plurality of pairs of adjacent octets for the indicated LCG are adjacent in the message and are arranged in increasing or decreasing order of corresponding importance level.

16. The method of claim 3, wherein: for each LCG indicated by the initial octet, the first octet includes an importance level indicator bit; and the importance level indicator bits for all LCGs indicated by the initial octet are logically combined into a bit field that indicates one or more importance levels associated with the buffered PDU sets for all LCGs indicated by the initial octet.

17. The method of claim 16, wherein the logically combined bit field indicates one of the following: a percentage or amount of buffered PDU sets for all indicated LCGs, that is high importance or delay-critical; or respective percentages or amounts of buffered PDU sets for the respective indicated LCGs, that are high importance or delay-critical.

18. The method of any of claims 1-17, further comprising receiving (1210) from the RAN node a reporting configuration that indicates one or more of the following: which importance levels should be reported for buffered PDU sets; which LCGs with associated buffered PDU sets should be reported; a threshold for distinguishing between high and low importance levels; reporting format to be used; and a buffer size mapping table to be used for reporting delay information, wherein the message transmitted to the RAN node is in accordance with the reporting configuration.

19. The method of any of claims 1-18, further comprising:in response to the message, receiving (1260) from the RAN node a grant of uplink resources; and transmitting (1270) at least a portion of the buffered data to the RAN node, using the granted uplink resources.

20. The method of any of claims 1-19, further comprising: in response to the message, receiving (1240) from the RAN node a discard configuration indicating one or more of the following: one or more importance levels for which associated buffered PDU sets may be discarded, and one or more importance levels for which associated buffered PDU sets should not be discarded; and selectively discarding (1250) the buffered PDU sets in accordance with the discard configuration.

21. The method of any of claims A1-A9, wherein one or more of the following applies: the message is a delay status report, DSR, medium access control, MAC, control element, CE; and the application is an extended reality, XR, application and the data generated by the application has a bounded latency requirement.

22. A method for a radio access network, RAN, node configured to receive application data from a user equipment, UE, the method comprising: receiving (1320) from the UE a message pertaining to buffered data generated by an application hosted by the UE, wherein: the buffered data comprises a plurality of sets of protocol data units (PDUs); each buffered PDU set is associated with the following: a logical channel group, LCG;, at least one importance level; and a packet data convergence protocol, PDCP, discard timer; and the message indicates the following: at least one LCG associated with buffered PDU sets; and delay information and one or more importance levels for the buffered PDU sets associated with the indicated at least one LCG.

23. The method of claim 22, wherein the delay information for each indicated LCG includes the following: a shortest remaining time on PDCP discard timers associated with the buffered PDU sets for the indicated LCG, and an amount of delay-critical data in the buffered PDU sets for the indicated LCG.

24. The method of any of claims 22-23, wherein: the message includes an initial octet of bits, with the bits of the initial octet being associated with respective ones of a plurality of LCGs; and the initial octet indicates LCGs, of the plurality of LCGs, for which the message indicates the delay information and the one or more importance levels.

25. The method of claim 24, wherein for each LCG indicated by the initial octet, the message includes a pair of adjacent octets arranged as: a first octet that includes indications of the one or more importance levels and the shortest remaining time on PDCP discard timers associated with the buffered PDU sets for the indicated LCG; and a second octet that indicates the amount of delay-critical data in the buffered PDU sets for the indicated LCG.

26. The method of claim 25, wherein for each LCG indicated by the initial octet, the first octet indicates one of the following: a single importance level of the buffered PDU sets for the indicated LCG; multiple different importance levels of the buffered PDU sets for the indicated LCG; or whether the message also includes a subsequent pair of adjacent octets for the indicated LCG.

27. The method of claim 26, wherein the indicated single importance level is one of the following a highest importance level of the buffered PDU sets for the indicated LCG; a lowest importance level of the buffered PDU sets for the indicated LCG; or an importance level having the most buffered data in the buffered PDU sets for the indicated LCG;28. The method of any of claims 26-27, wherein when first octet indicates the single importance level, the second octet indicates the amount of delay-critical data of the single importance level in the buffered PDU sets for the indicated LCG.

29. The method of any of claims 26-28, wherein the first octet includes a bit field of a plurality of bits, and respective values of the bit field indicate one of the following: respective one or more importance levels of the buffered PDU sets for the indicated LCG; or respective portions of the buffered PDU sets for the indicated LCG that are of highest importance level.

30. The method of claim 29, wherein the plurality of bits include a first bit that is configurable by the RAN node to be used as either of the following: a buffer size mapping table indicator bit, or an importance level indicator bit.

31. The method of claim 26, wherein when the first octet indicates that the message also includes a subsequent pair of adjacent octets: the first octet indicates the shortest remaining time on PDCP discard timers associated with the buffered PDU sets of a highest importance level for the indicated LCG; and the second octet indicates the amount of delay-critical data of the highest importance level in the buffered PDU sets for the indicated LCG.

32. The method of any of claims 26 and 31, wherein when the first octet indicates that the message also includes a subsequent pair of adjacent octets, the subsequent pair of adjacent octets is arranged as follows: a third octet that indicates the following: whether the message also includes another subsequent pair of adjacent octets for the indicated LCG, and the shortest remaining time on PDCP discard timers associated with the buffered PDU sets of a next highest importance level for the indicated LCG; and a fourth octet that indicates an amount of delay-critical data of the next highest importance level in the buffered PDU sets for the indicated LCG.

33. The method of claim 24, wherein for each LCG indicated by the initial octet, the message includes the following:one or more pairs of adjacent octets for the indicated LCG, with each pair arranged as: a first octet that indicates the shortest remaining time on PDCP discard timers associated with the buffered PDU sets for the indicated LCG, and a second octet that indicates the amount of delay-critical data in the buffered PDU sets for the indicated LCG; and a bit field in a further octet that is after the initial octet but before the one or more pairs of adjacent octets for the indicated LCG, wherein the bit field indicates the one or more importance levels for the indicated LCG.

34. The method of claim 33, wherein the bit field is the entire further octet, such that for each LCG indicated by the initial octet, the message includes a corresponding further octet located after the initial octet but before any pairs of adjacent octets for the LCGs indicated by the initial octet.

35. The method of any of claims 33-34, wherein for each LCG indicated by the initial octet: when the bit field in the further octet indicates a plurality of importance levels for the indicated LCG, the message includes a corresponding plurality of pairs of adjacent octets for the indicated LCG; each first octet indicates the shortest remaining time on PDCP discard timers associated with the buffered PDU set of the corresponding importance level for the indicated LCG, and each second octet indicates the amount of delay-critical data in the buffered PDU sets of the corresponding importance level for the indicated LCG.

36. The method of claim 35, wherein the plurality of pairs of adjacent octets for the indicated LCG are adjacent in the message, and are arranged in increasing or decreasing order of corresponding importance level.

37. The method of claim 24, wherein: for each LCG indicated by the initial octet, the first octet includes an importance level indicator bit; and the importance level indicator bits for all LCGs indicated by the initial octet are logically combined into a bit field that indicates one or more importance levels associated with the buffered PDU sets for all LCGs indicated by the initial octet.

38. The method of claim 37, wherein the logically combined bit field indicates one of the following: a percentage or amount of buffered PDU sets for all indicated LCGs, that is high importance or delay-critical; or respective percentages or amounts of buffered PDU sets for the respective indicated LCGs, that is high importance or delay-critical.

39. The method of any of claims 22-38, further comprising sending (1310) to the UE a reporting configuration that indicates one or more of the following: which importance levels should be reported for buffered PDU sets; which LCGs with associated buffered PDU sets should be reported; a threshold for distinguishing between high and low importance levels; reporting format to be used; and a buffer size mapping table to be used for reporting delay information, wherein the message received from the UE is in accordance with the reporting configuration.

40. The method of any of claims 22-39, further comprising: in response to the message, sending (1340) to the UE a grant of uplink resources; and receiving (1350) at least a portion of the buffered data from the UE using the granted uplink resources.

41. The method of any of claims 22-40, further comprising, in response to the message, sending (1330) to the UE a discard configuration indicating one or more of the following: one or more importance levels for which associated buffered PDU sets may be discarded, and one or more importance levels for which associated buffered PDU sets should not be discarded.

42. The method of any of claims 22-41, wherein one or more of the following applies: the message is a delay status report, DSR, medium access control, MAC, control element, CE; and the application is an extended reality, XR, application and the data generated by the application has a bounded latency requirement.

43. User equipment, UE (205, 310, 1412, 1500) configured to transmit application data to a radio access network, RAN, node (100, 210, 220, 320, 1410, 1600, 1702), the UE comprising: communication interface circuitry (1512) configured to communicate with the RAN node; and processing circuitry (1502) operatively coupled to the communication interface circuitry, wherein the processing circuitry and the communication interface circuitry are configured to: buffer data generated by an application hosted by the UE, wherein: the buffered data comprises a plurality of sets of protocol data units, PDUs; and each buffered PDU set is associated with the following: a logical channel group, LCG;, at least one importance level; and a packet data convergence protocol, PDCP, discard timer; and transmit to the RAN node a message that indicates the following: at least one LCG associated with the buffered PDU sets; and delay information and one or more importance levels for the buffered PDU sets associated with the indicated at least one LCG.

44. The UE of claim 43, wherein the processing circuitry and the communication interface circuitry are configured to perform operations corresponding to any of the methods of claims 2- 21.

45. User equipment, UE (205, 310, 1412, 1500) configured to transmit application data to a radio access network, RAN, node (100, 210, 220, 320, 1410, 1600, 1702), the UE being further configured to: buffer data generated by an application hosted by the UE, wherein: the buffered data comprises a plurality of sets of protocol data units, PDUs; and each buffered PDU set is associated with the following: a logical channel group, LCG;, at least one importance level; and a packet data convergence protocol, PDCP, discard timer; and transmit to the RAN node a message that indicates the following: at least one LCG associated with the buffered PDU sets; and delay information and one or more importance levels for the buffered PDU sets associated with the indicated at least one LCG.

46. The UE of claim 45, being further configured to perform operations corresponding to any of the methods of claims 2-21.

47. Non-transitory, computer-readable medium (1510) storing computer-executable instructions that, when executed by processing circuitry (1502) of user equipment, UE (205, 310, 1412, 1500) configured to transmit application data to a radio access network, RAN, node (100, 210, 220, 320, 1410, 1600, 1702), configure the UE to perform operations corresponding to any of the methods of claims 1-21.

48. Computer program product (1514) comprising computer-executable instructions that, when executed by processing circuitry (1502) of user equipment, UE (205, 310, 1412, 1500) configured to transmit application data to a radio access network, RAN, node (100, 210, 220, 320, 1410, 1600, 1702), configure the UE to perform operations corresponding to any of the methods of claims 1-21.

49. Radio access network, RAN, node (100, 210, 220, 320, 1410, 1600, 1702) configured to receive application data from user equipment, UE (205, 310, 1412, 1500), the RAN node comprising: communication interface circuitry (1606, 1704) configured to communicate with the UE; and processing circuitry (1602, 1704) operatively coupled to the communication interface circuitry, wherein the processing circuitry and the communication interface circuitry are configured to: receive from the UE a message pertaining to buffered data generated by an application hosted by the UE, wherein: the buffered data comprises a plurality of sets of protocol data units, PDUs; each buffered PDU set is associated with the following: a logical channel group, LCG; at least one importance level; and a packet data convergence protocol, PDCP, discard timer; and the message indicates the following: at least one LCG associated with buffered PDU sets; and delay information and one or more importance levels for the buffered PDU sets associated with the indicated at least one LCG.

50. The RAN node of claim 49, wherein the processing circuitry and the communication interface circuitry are further configured to perform operations corresponding to any of the methods of claims 23-42.

51. Radio access network, RAN, node (100, 210, 220, 320, 1410, 1600, 1702) configured to receive application data from user equipment, UE (205, 310, 1412, 1500), the RAN node being further configured to: receive from the UE a message pertaining to buffered data generated by an application hosted by the UE, wherein: the buffered data comprises a plurality of sets of protocol data units, PDUs; each buffered PDU set is associated with the following: a logical channel group, LCG; at least one importance level; and a packet data convergence protocol, PDCP, discard timer; and the message indicates the following: at least one LCG associated with buffered PDU sets; and delay information and one or more importance levels for the buffered PDU sets associated with the indicated at least one LCG.

52. The RAN node of claim 51, being further configured to perform operations corresponding to any of the methods of claims 23-42.

53. Non-transitory, computer-readable medium (1604, 1704) storing computer-executable instructions that, when executed by processing circuitry (1602, 1704) of a radio access network, RAN, node (100, 210, 220, 320, 1410, 1600, 1702) configured to receive application data from user equipment, UE (205, 310, 1412, 1500), configure the RAN node to perform operations corresponding to any of the methods of claims 22-42.

54. Computer program product (1604a, 1704a) comprising computer-executable instructions that, when executed by processing circuitry (1602, 1704) of a radio access network, RAN, node (100, 210, 220, 320, 1410, 1600, 1702) configured to receive application data from user equipment, UE (205, 310, 1412, 1500), configure the RAN node to perform operations corresponding to any of the methods of claims 22-42.