Timer based discarding of data units

Abstract

This disclosure provides systems, devices, apparatus, and methods, including computer programs encoded on storage media, for discarding data units. A UE (102) receives (420), from a network entity (104), a first indicator to enable discarding data units from a transmit buffer according to a first discard time period. The UE discards (440a), from the transmit buffer, a first data unit after expiration of the first discard time period starting from when the first data unit arrived at the transmit buffer. The UE receives (450), from the network entity (104), a second indicator to enable discarding data units from the transmit buffer according to a second discard time period having a different length than the first discard time period. The UE discards (440b), from the transmit buffer, a second data unit after expiration of the second discard time period starting from when the second data unit arrived at the transmit buffer.

Description

TIMER BASED DISCARDING OF DATA UNITSCROSS REFERENCE TO RELATED APPLICATION(S)

[0001] This application claims the benefit of and priority to U.S. Provisional Application Serial No. 63 / 586,633, entitled “Timer Based Discarding of Data Units” and filed on September 29, 2023, which is expressly incorporated by reference herein in its entirety.TECHNICAL FIELD

[0002] The present disclosure relates generally to wireless communication, and more particularly, to methods and apparatuses for timer based discarding of data units.BACKGROUND

[0003] The Third Generation Partnership Project (3GPP) specifies a radio interface referred to as fifth generation (5G) new radio (NR) (5G NR). An architecture for a 5G NR wireless communication system (5GS) includes a 5G core (5GC) network, a 5G radio access network (5G-RAN), a user equipment (5G UE), etc. The 5G NR architecture seeks to provide increased data rates, decreased latency, and / or increased capacity7compared to prior generation cellular communication systems.

[0004] Wireless communication systems, in general, provide various telecommunication services (e.g., telephony, video, data, messaging, etc.) based on multiple-access technologies, such as orthogonal frequency division multiple access (OFDMA) technologies, that support communication with multiple UEs. Improvements in mobile broadband continue the progression of such wireless communication technologies.

[0005] A user equipment (UE) software application queues data that eventually reaches a transmit buffer (e.g., a service data adaption protocol (SDAP) buffer, a packet data convergence protocol (PDCP) buffer, a radio link control (RLC) buffer, and / or a medium access control (MAC) buffer) for transmission to a network entity. The data is organized into data units (e.g., protocol data units (PDUs), PDU Sets, service data units (SDUs), Data Bursts, Data Burst Groups, etc.). A data unit carries a payload of one unit of information from data generated at an upper layer. When a netw ork entity detects network congestion, a conventional UE data unit discarding procedure might be unable to alleviate the network congestion.BRIEF SUMMARY

[0006] The following presents a simplified summary of one or more aspects in order to provide a basic understanding of such aspects. This summary is not an extensive overview of all contemplated aspects. This summary neither identifies key or critical elements of all aspects nor delineates the scope of any or all aspects. Its sole purpose is to present some concepts of one or more aspects in a simplified form as a prelude to the more detailed description that is presented later.

[0007] Data units transmitted by the UE may have a different level of importance based on the ty pe of data (e.g., i-frame video data, p-frame video data, audio data, haptic data, pose data, etc.) and / or the type of application associated with the data unit (e.g., extended reality (XR) application, conversational or live video, non-conversational or buffered video, conversational voice, etc ). The data units may be classified according to a PDU Set importance (PSI) level, which identifies the relative importance / priority of a data unit compared to other data units within a quality of service (QoS) flow. A radio access network (RAN) uses PSI for controlling UE data unit discarding (e.g., PDU Set packet discarding) in the presence of network congestion. The network entity selects which UE(s) to enable for data unit discarding. For example, the network entity selects UE(s) based on UE buffer status reports or delay status reports providing any of: PSIs of data units, delay information for data units, a data rate for the data units on a per-PSI basis, and / or an amount of data units in the transmit buffer of the UE.

[0008] The network entity transmits a first indicator (e.g., via broadcast, unicast, or groupcast messaging) to the selected UEs to enable data unit discarding based on a first discard time period and / or a PSI. For example, the network entity indicates to the UE a first discard time period value (e.g., a delay budget associated with the data units). The UE starts a discard timer when a data unit arrives in a transmit buffer (e.g.. arrive from an upper layer). If the UE does not transmit the data unit before the timer expires, the UE discards the data unit with an indicated PSI. Each PSI may have the same or a different discard time period. When a data unit arrives in the transmit buffer, a discard timer is started for that new data unit. Alternatively, the same discard timer value is used for any PSI level, and if the UE does not transmit the data unit before the discard timer expires, the UE discards the data unit regardless of the PSI. In other words, the UE discards the data unit during a window of time (e.g., a rolling window of time) that starts when each data unit arrives at the transmit buffer.

[0009] Discarding a data unit after a first discard timer expires helps to alleviate network congestion because the discarded data unit will not be transmitted to the network entity. The network entity periodically reassesses the network congestion level. Sometimes, despite thefirst indicator triggering data unit discarding, the network entity may determine that the network congestion has not been alleviated to a target congestion level.

[0010] To address this problem (and others), the network entity implements network congestion control techniques that further reduce network congestion by configuring the UE to discard a data unit sooner than the data unit discard process using the first discard time period. For example, the network entity transmits a second indicator to the UE to change the rate of discarding a data unit from the transmit buffer. In some aspects, the network entity indicates to the UE a second discard time period (e.g., a shorter time period than the first discard time period). In some aspects, the network entity transmits the second indicator to the UE without transmitting the first indicator to the UE. The indication may be an absolute time period, a relative time period (e.g., a scaling factor applied to the first time period), and / or an index to a table of time periods stored at the UE.

[0011] Additionally or alternatively, the UE may determine the start time and value for the second discard time period without receiving the second indicator, which reduces signaling overhead. The UE may change (e.g., decrease) the data unit timer period from the first discard time period to the second discard time period after a time window. The time window and second discard time period value may be included with the first indicator or using a different signaling mechanism. For example, the UE may select the second discard time period from a table of second discard time periods received from the network entity via RRC messaging. Alternatively, the UE may change the data unit timer period from the first discard time period to the second data discard time period by applying a scaling factor to the first discard time period. In some aspects, the UE may scale down (e.g., shorten) the timer multiple times until the network entity transmits a third indicator to the UE to disable data unit discarding.

[0012] In some aspects, the network entity configures the UE with an On / Off discard cycle period for discarding a data unit according to the first discard time period and / or the second discard time period. The UE receives On / Off discard cycle parameters from the network entity indicating a first discard cycle time period (e.g., On period) and a second discard cycle time period (e.g., Off period). When the UE receives the first data unit into a transmit buffer during the first discard cycle time period (e.g., On period), the UE discards the first data unit when the first discard time period expires. When the UE receives a data unit into the transmit buffer during the second discard cycle time period (e.g., Off period), the UE refrains from discarding that data unit after expiration of the first discard time period. However, during all time periods, the UE still discards the fourth data unit after expiration of a legacy data unitdiscard time period (e.g., 3GPP TS 38.323 discardTimer) that is longer than the first discard time period.

[0013] In order to assist the network entity in determining the PSI for discarding a data unit, the UE(s) in the wireless network transmit a data unit parameter to the network entity . A data unit parameter indicates: (a) an amount of data in the transmit buffer that stores the data unit and / or (b) a data rate for the data unit. The data rate may be determined by the application. Other types of data unit parameters may include: (c) data volume information for a data unit for a logical channel (LCH) or a logical channel group (LCG) or (d) data volume information of urgent data in a transmit buffer for a LCH or LCG whose remaining time for delivery is less than or equal to a given threshold configured by the network. Data unit parameters may be received individually or together as part of various status reports, such as a buffer status report (BSR) or a delay status report (DSR). These status reports may separate out data unit parameters on a per-PSI, per-LCH, and / or pre-LCG basis.

[0014] According to some aspects, a UE receives, from a network entity’, a first indicator to enable data unit discarding. After receiving the first indicator, the UE discards a first data unit after expiration of a first discard time period starting from when the first data unit entered a transmit buffer. The UE receives, from the network entity7, a second indicator to enable the data unit discarding according to a second discard time period. After receiving the second indicator, the UE discards a second data unit after expiration of the second discard time period starting from when the first data unit entered a transmit buffer.

[0015] According to some aspects, a network entity7transmits, to a UE, a first indicator to enable data unit discarding. The network entity transmits, to the UE based on a network congestion level, a second indicator to enable the data unit discarding according to a second discard time period. The network entity transmits, to the UE based on the network congestion level, a third indicator to disable the data unit discarding.

[0016] According to some aspects, a UE receives, from a network entity7, a first indicator to enable discarding a data unit during a discard cycle having a first discard cycle time period and a second discard cycle time period. The UE discards a first data unit received in a transmit buffer during the first discard cycle time period, after expiration of a first discard time period. The UE discards, a fourth data unit received in the transmit buffer during the second discard cycle time period, after expiration of a legacy data unit discard time period that is longer than the first discard time period.

[0017] Technical benefits of the present disclosure include assisting the network entity in alleviating network congestion by configuring the UE to increase the rate of data unit discarding. Further benefits include the network entity and / or the UE controlling the enabling / disabling of data unit discarding using example techniques described herein. Further benefits include the network entity and / or the UE controlling the discarding of data units using the examples described with reference to FIGs. 2-9.BRIEF DESCRIPTION OF THE DRAWINGS

[0018] FIG. 1 illustrates a diagram of a wireless communications system that includes a plurality of user equipments (UEs) and network entities in communication over one or more cells according to an embodiment.

[0019] FIG. 2 illustrates a diagram of a wireless communications system that includes a plurality of UEs and a network entity' in communication over access links according to an embodiment.

[0020] FIG. 3 A is a diagram illustrating a timeline for UE data unit discarding based on first and second indicators according to an embodiment.

[0021] FIG. 3B is a diagram illustrating a timeline for UE data unit discarding based on a first indicator according to an embodiment.

[0022] FIG. 4 is a signaling diagram illustrating communications between a UE and a network entity for discarding a first data unit according to a first discard time period and a second data unit according to a second discard time period according to an embodiment.

[0023] FIG. 5 is a signaling diagram illustrating communications between a UE and a network entity for discarding a first data unit according to a first discard time period and a second data unit according to a second discard time period according to another embodiment.

[0024] FIG. 6 is a flowchart of a method of wireless communication at a UE according to an embodiment with a first discard time period and a second discard time period.

[0025] FIG. 7 is a flowchart of a method of wireless communication at a network entity according to an embodiment with a first discard time period and a second discard time period.

[0026] FIG. 8 is a flowchart of a method of wireless communication at a UE according to another embodiment.

[0027] FIG. 9 is a flowchart of a method of wireless communication at a network entity according to another embodiment.

[0028] FIG. 10 is a diagram illustrating a hardware implementation for an example UE apparatus according to some embodiments.

[0029] FIG. 11 is a diagram illustrating a hardware implementation for one or more example network entities according to some embodiments.

[0030] In FIGs. 1-11 like reference numbers refer to like actions.DETAILED DESCRIPTION

[0031] FIG. 1 illustrates a diagram 100 of a wireless communications system associated with a plurality of cells 190. The wireless communications system includes user equipments (UEs) 102 and base stations / network entities 104. Some base stations may include an aggregated base station architecture and other base stations may include a disaggregated base station architecture. The aggregated base station architecture utilizes a radio protocol stack that is physically or logically integrated within a single radio access network (RAN) node. A disaggregated base station architecture utilizes a protocol stack that is physically or logically distributed among two or more units (e.g., radio unit (RU) 106, distributed unit (DU) 108, central unit (CU) 110). For example, a CU 110 is implemented within aRAN node, and one or more DUs 108 may be co-located with the CU 110, or alternatively, may be geographically or virtually distributed throughout one or multiple other RAN nodes. The DUs 108 may be implemented to communicate with one or more RUs 106. Any of the RU 106, the DU 108 and the CU 110 can be implemented as virtual units, such as a virtual radio unit (VRU), a virtual distributed unit (VDU), or a virtual central unit (VCU). The base station / network entity 104 (e.g., an aggregated base station or disaggregated units of the base station, such as the RU 106 or the DU 108), may be referred to as a transmission reception point (TRP).

[0032] Operations of the base station 104 and / or network designs may be based on aggregation characteristics of base station functionality. For example, disaggregated base station architectures are utilized in an integrated access backhaul (IAB) network, an open-radio access network (O-RAN) network, or a virtualized radio access network (vRAN), which may also be referred to a cloud radio access network (C-RAN). Disaggregation may include distributing functionality across the two or more units at various physical locations, as well as distributing functionality' for at least one unit virtually, which can enable flexibility' in network designs. The various units of the disaggregated base station architecture, or the disaggregated RAN architecture, can be configured for wired or wireless communication with at least one other unit. For example, the base stations 104d, 104e and / or the RUs 106a, 106b, 106c, 106dmay communicate with the UEs 102a, 102b, 102c. 102d, and / or 102s via one or more radio frequency (RF) access links based on a Uu interface. In examples, multiple RUs 106 and / or base stations 104 may simultaneously serve the UEs 102, such as by intra-cell and / or inter-cell access links between the UEs 102 and the RUs 106 / base stations 104.

[0033] The RU 106, the DU 108, and the CU 110 may include (or may be coupled to) one or more interfaces configured to transmit or receive information / signals via a wired or wireless transmission medium. For example, a wired interface can be configured to transmit or receive the information / signals over a wired transmission medium, such as via the fronthaul link 160 between the RU 106d and the baseband unit (BBU) 112 of the base station 104d associated with the cell 190d. The BBU 112 includes a DU 108 and a CU 110, which may also have a wired interface (e.g., midhaul link) configured between the DU 108 and the CU 110 to transmit or receive the information / signals between the DU 108 and the CU 110. In further examples, a wireless interface, which may include a receiver, a transmitter, or a transceiver, such as an RF transceiver, configured to transmit and / or receive the information / signals via the wireless transmission medium, such as for information communicated between the RU 106a of the cell 190a and the base station 104e of the cell 190e via cross-cell communication beams 136-138 of the RU 106a and the base station 104e.

[0034] The RUs 106 may be configured to implement lower layer functionality. For example, the RU 106 is controlled by the DU 108 and may correspond to a logical node that hosts RF processing functions, or lower layer PHY functionality, such as execution of fast Fourier transform (FFT), inverse FFT (iFFT), digital beamforming, physical random access channel (PRACH) extraction and filtering, etc. The functionality of the RU 106 may be based on the functional split, such as a functional split of lower layers.

[0035] The RUs 106 may transmit or receive over-the-air (OTA) communication with one or more UEs 102. For example, the RU 106b of the cell 190b communicates with the UE 102b of the cell 190b via a first set of communication beams 132 of the RU 106b and a second set of communication beams 134b of the UE 102b. which may correspond to inter-cell communication beams or, in some examples, cross-cell communication beams. For instance, the UE 102b of the cell 190b may communicate with the RU 106a of the cell 190a via a third set of communication beams 134a of the UE 102b and a fourth set of communication beams 136 of the RU 106a. DUs 108 can control both real-time and non-real-time features of control plane and user plane communications of the RUs 106.

[0036] Any combination of the RU 106, the DU 108. and the CU 110, or reference thereto individually, may correspond to a base station 104. Thus, the base station 104 may include at least one of the RU 106, the DU 108, or the CU 110. The base stations 104 provide the UEs 102 with access to a core network. The base stations 104 may relay communications between the UEs 102 and the core network (not shown). The base stations 104 may be associated with macrocells for higher-power cellular base stations and / or small cells for lower-power cellular base stations. For example, the cell 190e may correspond to a macrocell, whereas the cells 190a-190d may correspond to small cells. Small cells include femtocells, picocells, microcells, etc. A network that includes at least one macrocell and at least one small cell may be referred to as a “heterogeneous network.’7

[0037] Transmissions from a UE 102 to a base station 104 / RU 106 are referred to as uplink (UL) transmissions, whereas transmissions from the base station 104 / RU 106 to the UE 102 are referred to as downlink (DL) transmissions. Uplink transmissions may also be referred to as reverse link transmissions and downlink transmissions may also be referred to as forward link transmissions. For example, the RU 106d utilizes antennas of the base station 104d of cell 190d to transmit a downlink / forward link communication to the UE 102d or receive an uplink / reverse link communication from the UE 102d based on the Uu interface associated with the access link between the UE 102d and the base station 104d / RU 106d.

[0038] Communication links between the UEs 102 and the base stations 104 / RUs 106 may be based on multiple-input and multiple-output (MIMO) antenna technology, including spatial multiplexing, beamforming, and / or transmit diversity. The communication links may be associated with one or more carriers. The UEs 102 and the base stations 104 / RUs 106 may utilize a spectrum bandwidth of Y MHz (e.g., 5, 10, 15, 20, 100, 400, 800, 1600, 2000, etc. MHz) per earner allocated in a carrier aggregation of up to a total of Yx MHz, where x component carriers (CCs) are used for communication in each of the uplink and downlink directions. The carriers may or may not be adjacent to each other along a frequency spectrum. In examples, uplink and downlink carriers may be allocated in an asymmetric manner, with more or fewer carriers allocated to either the uplink or the downlink. A primary component carrier and one or more secondary component carriers may be included in the component carriers. The primary component carrier may be associated with a primary cell (PCell) and a secondary component carrier may be associated with a secondary cell (SCell).

[0039] Some UEs 102. such as the UEs 102a and 102s, may perform device-to-device (D2D) communications over sidelink. For example, a sidelink communication / D2D linkutilizes a spectrum for a wireless wide area network (WWAN) associated with uplink and downlink communications. Such sidelink / D2D communication may be performed through various wireless communications systems, such as wireless fidelity (Wi-Fi) systems, Bluetooth systems, Long Term Evolution (LTE) systems, New Radio (NR) systems, etc.

[0040] The UEs 102 and the base stations 104 / RUs 106 may each include a plurality of antennas. The plurality of antennas may correspond to antenna elements, antenna panels, and / or antenna arrays that may facilitate beamforming operations. For example, the RU 106b transmits a downlink beamformed signal based on a first set of communication beams 132 to the UE 102b in one or more transmit directions of the RU 106b. The UE 102b may receive the downlink beamformed signal based on a second set of communication beams 134b from the RU 106b in one or more receive directions of the UE 102b. In a further example, the UE 102b may also transmit an uplink beamformed signal (e.g., sounding reference signal (SRS)) to the RU 106b based on the second set of communication beams 134b in one or more transmit directions of the UE 102b. The RU 106b may receive the uplink beamformed signal from the UE 102b in one or more receive directions of the RU 106b. The UE 102b may perform beam training to determine the best receive and transmit directions for the beamformed signals. The transmit and receive directions for the UEs 102 and the base stations 104 / RUs 106 may or may not be the same.

[0041] In further examples, beamformed signals may be communicated between a first base station / RU 106a and a second base station 104e. For instance, the base station 104e of the cell 190e may transmit a beamformed signal to the RU 106a based on the communication beams 138 in one or more transmit directions of the base station 104e. The RU 106a may receive the beamformed signal from the base station 104e of the cell 190e based on the RU communication beams 136 in one or more receive directions of the RU 106a. In further examples, the base station 104e transmits a downlink beamformed signal to the UE 102e based on the communication beams 138 in one or more transmit directions of the base station 104e. The UE 102e receives the downlink beamformed signal from the base station 104e based on UE communication beams 130 in one or more receive directions of the UE 102e. The UE 102e may also transmit an uplink beamformed signal to the base station 104e based on the UE communication beams 130 in one or more transmit directions of the UE 102e, such that the base station 104e may receive the uplink beamformed signal from the UE 102e in one or more receive directions of the base station 104e.

[0042] The base station 104 may include and / or be referred to as a network entity. That is, ‘'network entity” may refer to the base station 104 or at least one unit of the base station 104, such as the RU 106, the DU 108, and / or the CU 110. The base station 104 may also include and / or be referred to as a next generation evolved Node B (ng-eNB), a next generation NB (gNB), an evolved NB (eNB), an access point, a base transceiver station, a radio base station, a radio transceiver, a transceiver function, a basic service set (BSS), an extended service set (ESS), a TRP, a network node, network equipment, or other related terminology. The base station 104 or an entity at the base station 104 can be implemented as an IAB node, a relay node, a sidelink node, an aggregated (monolithic) base station, or a disaggregated base station including one or more RUs 106. DUs 108. and / or CUs 110. A set of aggregated or disaggregated base stations may be referred to as a next generation-radio access network (NG- RAN). In some examples, the UE 102a operates in dual connectivity (DC) with the base station 104e and the base station / RU 106a. In such cases, the base station 104e can be a master node and the base station / RU 160a can be a secondary node.

[0043] Still referring to FIG. 1, in certain aspects, any of the UEs 102 may include a data unit discard component 140 configured to receive, from a network entity, a first indicator to enable discarding data units. The data unit discard component 140 is further configured to discard a first data unit after expiration of a first discard time period. The data unit discard component 140 is further configured to receive, from the network entity, a second indicator to enable the data unit discarding according to a second discard time period. The data unit discard component 140 is further configured to discard a second data unit after expiration of the second discard time period.

[0044] Still referring to FIG. 1. in certain aspects, any of the UEs 102 may include a data unit discard component 140 configured to receive, from a network entity, a first indicator to enable discarding data units during a discard cycle having a first discard cycle time period and a second discard cycle time period. The data unit discard component is further configured to discard a first data unit received in a transmit buffer during the first discard cycle time period, after expiration of a first discard time period. The data unit discard component 140 is further configured to discard a fourth data unit received in a transmit buffer during the second discard cycle time period, after expiration of a legacy data unit discard time period that is longer than the first discard time period.

[0045] In certain aspects, any of the base stations 104 or a network entity of the base stations 104 may include a congestion control component 150 configured to transmit, to a UEbased on a network congestion level, a first indicator to enable first data unit discarding according to a first discard time period. The congestion control component 150 is further configured to transmit, to the UE based on a change in the network congestion level, a second indicator to enable second data unit discarding according to a second discard time period.

[0046] Accordingly, FIG. 1 describes a wireless communication system that may be implemented in connection with aspects of one or more other figures described herein. Further, although the following description may be focused on 5G NR, the concepts described herein may be applicable to other similar areas, such as 5G- Advanced and future versions, LTE, LTE- advanced (LTE- A), and other wireless technologies, such as 6G.

[0047] FIG. 2 illustrates a diagram 200 of a wireless communications system that includes a plurality of UEs 102 and a network entity 104 in communication over access links 250 (e.g., Uu access links) according to an embodiment. In some aspects, a UE 102 software application (e.g., extended reality (XR) application) queues data that eventually reaches a transmit buffer for uplink transmission to network entity 104. The data is organized into data units (e.g., protocol data units (PDUs), PDU Sets, service data units (SDUs), Data Bursts, Data Burst Groups, etc.).

[0048] In some aspects, the network entity 104 detects that the network congestion level on access links 250 has reached a threshold. The network congestion may be caused by uplink data bursts or core network congestion affecting downhnk / uplink radio access. To alleviate the network congestion, network entity 104 and UEs 102 begin congestion control techniques that leverage UE information and additional controls as described below wi th reference to FIGs. 3- 9. The network entity 104 configures the UE 102 to discard a first data unit according a first discard timer. To address the problem of the network congestion not being alleviated based on the UE discarding a first data unit according the first discard timer, the network entity transmits an indicator to the UE to begin discarding a second data unit according to a second discard timer. Alternatively, the UE 102 determines the second discard timer and begins discarding the second data unit according to a second discard timer. In some aspects, the second discard timer is shorter than the first discard timer.

[0049] The network entity 104 implements network congestion control techniques that leverage UE 102 information and additional controls (e.g., an amount of data per data unit, an indication that the data unit comprises single-modal data, an indication that the data unit comprises multi-modal data, a PSI of the data unit, a buffer status report (BSR), or a data rate of the data unit, etc.). The relative importance of the data unit is dictated by the PSI. UEs 102(e.g., UE 102a. UE 102b, and UE 102n) may set a PSI based on a data unit type. For example, when UEs 102 are transmitting video data (e.g., XR video data) to the network entity 104, UEs 102 configure a first data unit type containing I-frame video data to have a higher importance than a second data unit type containing P-frame video data. In some aspects, the PSI may have a range of values (e.g., 2 values, 4 values, 8 values, 16 values, etc.) in which a higher PSI value indicates a higher data unit ty pe importance. Alternatively, a lower PSI value indicates a higher data unit ty pe importance.

[0050] The network entity7104 selects which UE(s) 102 (e.g., UE 102a, UE 102b, or UE 102n) to enable for data unit discarding. For example, the network entity 104 selects UE(s) 102 based on UE 102 buffer status reports, a PSI of the data units, a data rate for each PSI of the data units, and / or an amount of data units in the transmit buffer of the UE 102. The network entity7104 transmits a first indicator (e.g., via broadcast, unicast, or groupcast messaging) to the selected UEs 102 to enable data unit discarding based on a first discard time period and optionally a PSI. For example, the network entity 104 indicates a first discard time period (e.g., a delay budget associated with the first data unit) to the UE 102. The UE 102 starts the first discard timer when the first data unit arrives in a transmit buffer (e.g., arrives in a PDCP buffer from an XR application). If the UE 102 does not transmit the first data unit before the timer expires, the UE 102 discards the first data unit optionally with an indicated PSI. Each PSI may have the same or a different discard time period (e.g., up to 16 discard time period values for 1 PSI values). Alternatively, if the UE 102 does not transmit the first data unit before the timer expires, the UE 102 discards the first data unit regardless of the PSI.

[0051] FIG. 3A is a diagram 300 illustrating a timeline for UE 102 data discarding based on the UE 102 receiving first and second indicators from a network entity according to an embodiment. In some aspects, a network entity 104 determines a network congestion level nears or exceeds a threshold. In order to alleviate the network congestion, the network entity 104 configures the UE 102 to discard data units. At time tl, the network entity7104 transmits a first indicator 303 to the UE 102 to begin data unit discarding according to a first discard time period T4 304 (e.g., a first discard timer period) and optionally a PSI. Each PSI may correspond to the same or a different first discard time period value (e.g., T4-1, T4-2). At time t3, the UE 102 receives a first data unit in a transmit buffer from an upper layer and starts a first discard period timer T4 304a. If the first discard period timer T4 304a expires before the UE 102 transmits the first data unit, the UE 102 discards the first data unit at time t4. As another example, at t5, the UE 102 receives a third data unit into the buffer from the upper layer andstarts another first discard period timer T4 304b. The UE 102 may have multiple overlapping discard timers running where each discard timer starts when additional data units arrive in the buffer. If the first discard period timer T4 304b expires before the UE 102 transmits the third data unit, the UE 102 discards the third data unit at time t6.

[0052] If the network congestion is not alleviated while the UE uses the first discard time period T4 304, the network entity 104 transmits a second indicator 311 to the UE 102 (shown at time t2) for the UE 102 to start discarding a second data unit indicating according to a second discard time period 305 and optionally a PSI. At t7, which occurs after 12, the UE receives a second data unit in the transmit buffer from the upper layer and starts a second discard period timer T5 305. As shown in FIG. 3A the second discard time period T5 305 is shorter than the first discard time period T4 304 resulting in the UE 102 discarding the second data unit sooner relative to the first discard time period T4 304 and further alleviating the netw ork congestion. If the second discard period timer T5 305 expires before the UE 102 transmits the second data unit, the UE 102 discards the second data unit at time t8. In some aspects, the first data unit, the second data unit, and the third data unit have the same PSIs and belong to the same radio bearer or logical channel or logical channel group.

[0053] In some aspects, the network entity' 104 configures the UE 102 with an On / Off discard cycle period T3 312 for discarding data units according to the first discard time period T4 304 and / or the second discard time period T5 305. The UE 102 receives On / Off discard cycle parameters from the network entity 104 indicating an On period T1 314 (e.g., a first discard cycle time period) and an Off period T2 315 (e.g., a second discard cycle time period). For example, the network entity 104 transmits the On / Off discard cycle parameters in one or more RRC messages (e.g. RRCReconfiguration, RRCRelease, RRCSetup. or RRCReestablishment message). When the UE 102 receives the first indicator 303, the UE 102 periodically starts the On / Off discard cycle timer. For example, when UE 102 receives the first indicator 303 in subframe n, the UE 102 periodically starts the On / Off discard cycle timer in the subframe (n+m+k*periodicity) or (k*periodicity), where m is predefined or configured by the network entity 104 and k is an integer. In another example, the UE 102 periodically starts the On / Off discard cycle timer in the subframe (k*periodicity), where k is an integer. The UE 102 receives the first data unit into the transmit buffer at t3 during the On period T1 314 and discards the first data unit at t4 when the first discard time period T4 304a expires similar to the earlier explanation. At tlO, the UE 102 receives a fourth data unit into the transmit buffer during the Off period T2315 and refrains from discarding the fourth data unit based on the firstdiscard time period T4 304. Instead, during the Off period T2 315, the UE 102 discards the fourth data unit after expiration of a legacy discard time period that is longer than the first discard time period T4 304. In this manner, data units arriving in the buffer during the Off period T2 315 have an increased probability of being transmitted by the UE 102 as compared to data units arriving in the buffer during the On period T1 314.

[0054] The network entity 104 optionally transmits a third indicator 370 at time ti l to disable data unit discarding for network congestion alleviation. For example, all discard timers for transmit buffers revert to their legacy discard time period values. The UE 102 continues to discard data units until the UE 102 receives the third indicator 370 from the network entity 104 directing the UE 102 to refrain from data unit discarding for network congestion alleviation.

[0055] FIG. 3A illustrates a timeline for the UE 102 to receive a first indicator to discard a first data unit based on the first discard time period 304 and receive a second indicator to discard a second data unit based on the second discard time period 305. FIG. 3B illustrates a timeline for the UE 102 to receive a first indicator to discard a first data unit based on the first discard time period 304 and subsequently discard a second data unit based on the second discard time period 305 without receiving the second indicator from the network entity 104.

[0056] FIG. 3B is a diagram 350 illustrating a timeline for UE 102 data discarding based on the UE 102 receiving a first indicator from a network entity according to an embodiment. The UE 102 receives a first indicator at tl 303 from the network entity 104 for the UE 102 to apply a first discard time period 304 to a first data unit arriving in the buffer during the first time window T6 307 and apply a second discard time period T5 305 to a second data unit arriving in the buffer after the first time window T6 307. The network entity 104 may include the value of the first time window T6 307 with the indicator, or the length of the first time window T6 307 may be set by a standard or signaled in an RRC message.

[0057] The operation of various discard timers on incoming first and second data units has been described with reference to FIG. 3A. After expiration of the first time window T6 307, at time t9 shown in FIG. 3B, the UE 102 switches to applying the second discard time period T5 305 to data discarding. The UE proceeds to discard a second data unit according to the second discard time period T5 305 value, and continue discarding incoming data units according to the second discard time period T5 305 value, until the UE receives a third indicator 370 at time tl 1 disabling data unit discarding for network congestion alleviation, as previously described.

[0058] FIG. 4 is a signaling diagram of a method 400 illustrating communications between a UE 102 and a network entity 104 for discarding data units according to an embodiment in a wireless communications system as shown in FIGs. 1-2. The signaling diagram of FIG. 4 corresponds to the timing diagram of FIG. 3 A in which the network entity 104 transmits a first indicator to the UE 102 to enable data unit discarding according to a first discard timer and a second indicator to enable data discarding according to a second discard timer.

[0059] The UE 102 transmits 405 a data unit parameter report to the netw ork entity 104. In this regard, the UE 102 transmits 405 the data unit parameter report to the network entity 104 using a radio resource control (RRC) message, a medium access control-control element (MAC-CE), an SDAP control PDU, a PDCP control PDU, an RLC control PDU, or other suitable communication. The data unit parameter report includes several parameters for each data unit type (e.g., PDU Set Type). For example, the parameters include data rate, data rate range, PSI. data modality (e.g.. single-modal data or multi-modal data), data volume, data volume information for a data unit for a LCH or a LCG, data volume information of urgent data in a transmit buffer for a LCH or LCG whose remaining time for delivery is less than or equal to a given threshold configured by the netw ork. Data unit parameters may be received individually or together as part of various status reports, such as a BSR or a DSR. These status reports may separate out data unit parameters on a per-PSl, per-LCH, and / or per-LCG basis. The PSI indicates a relative importance of a data unit. In some aspects, if UE 102 generates data with certain PSI values (e.g., PSI 1, PSI 5, and PSI 7), the UE 102 transmits the data unit parameter report indicating the certain PSI values (e.g., PSI 1, PSI 5, and PSI 7) to network entity 104. The network entity 104 uses this information to determine an optional PSI threshold for the UE to discard data units. The PSI of a data unit is determined by the software application generating the data units. In some aspects, the UE 102 periodically transmits 405 a data unit parameter report to the network entity 104. The periodicity of transmitting the data unit parameter report is configured (e.g., via RRC message) by the network entity 104.

[0060] In some aspects, an application (e.g., XR application) running on the UE 102 determines the data rates to report. In some aspects, the data rate is an average (e.g., statistical average) of data rates. For example, the UE 102 determines a data rate to report by dividing the total data volume of the data units over the time period when the data arrives in the transmit buffer from the application layer (or upper layers). Additionally or alternatively, the UE 102 determines the data rate by aggregating the data rates from more than one data unit ty pe.Additionally or alternatively, the UE 102 indicates the data rate as a range of data rates. For example, the UE 102 may store a lookup table having a set of indexes corresponding to a range of data rates. The UE 102 transmits the data unit parameter report including an index to the range of data rates that the measured data rate for the data units falls into. Other types of data unit parameters include data volume information per data unit type for a logical channel group or data volume information of urgent data in a transmit buffer for a logical channel or a logical channel group whose remaining time for delivery is less than or equal to a threshold. In some aspects, the data unit parameter report may include a bitmap with each bit indicating a data unit type and transmit buffer status.

[0061] The network entity 104 optionally transmits 410 a data unit discarding configuration the UE 102. In this regard, network entity 104 transmits 410 the data unit discarding configuration to the UE 102 using an RRC message and / or a MAC-CE. The data unit discarding configuration indicates the first discard time period value (optionally for a plurality of PSIs), a table of second discard time period values (optionally for the plurality of PSIs), a table of scaling factors (optionally for the plurality of PSIs), a table of second discard time period values (optionally for the plurality of PSIs), a PSI group indicator, and / or a PSI group threshold.

[0062] The network entity 104 measures 415a a first network congestion level in order to determine whether to enable data unit discarding to alleviate network congestion. The network entity' 104 determines 415a whether the first network congestion level fulfills a threshold criterion. For example, if the total data volume reported by the UE 102 and / or other UEs 102 (see FIG. 2) is larger than or equal to a threshold, the network entity 104 enables data unit discarding. Each UE 102 reports a transmit buffer total data volume using the data unit parameter report and / or a BSR and / or a DSR. Additionally or alternatively, if the total data volume of urgent data (e.g., data with a low latency budget) reported by the UE 102 and / or other UEs 102 is larger than or equal to a threshold, the network entity 104 enables data unit discarding. The network entity 104 periodically determines 415 (e.g., reassesses) the network congestion level. The UE 102 discards the data unit after the discard timer expires to help alleviate network congestion because the discarded data unit will not be transmitted to the network entity 104.

[0063] The network entity 104 selects one or more UEs 102 to enable data unit discarding. For example, the network entity 104 selects the UE 102 to enable data unit discarding when the importance (e g., PSI) of the reported data unit types is lower than other UEs 102. In thisway, the network entity 104 selects lower priority data (e.g.. p-frame data) for discarding. In some aspects, the network entity 104 determines an amount of uplink data from the UE(s) 102 that needs to be reduced (e.g., discarded) in order to alleviate the network congestion. If multiple UEs 102 report a data unit of the same PSI. the network entity 104 may select the UE 102 reporting the higher data rate for that data unit type in order to reduce signaling overhead. Additionally or alternatively, if multiple UEs 102 report data of the same PSI, the network entity 104 may select the UE 102 reporting the lower data rate for that data unit type to begin data unit discarding.

[0064] The network entity transmits 420 (e g., via broadcast, unicast, or groupcast messaging), based on the data unit parameter report and the first network congestion level, a first indicator to the UE 102 to enable data unit discarding according to the first discard time period (e.g., equivalent to a delay budget associated with the first data unit). In this regard, the network entity transmits 420 the first indicator via DCI, a MAC-CE, an RRC message, or other suitable communication. The first indicator may indicate the first discard time period value and / or a PSI threshold.

[0065] The UE 102 receives 430a data units in a transmit buffer from a higher layer (e.g., an application layer). For example, referring to FIG. 3 A, the UE 102 receives 430a a first data unit in the transmit buffer at t3 and a third data unit in the transmit buffer at t5. The data units may include a PDU. a PDU Set, a PDU Set group, a service data unit (SDU), a Data Burst and / or Data Burst group.

[0066] The UE 102 starts the first discard period timer 304 when each of the data units arrive in the transmit buffer (e.g., arrive from an upper layer or from an application). If the UE 102 does not transmit the data units before their respective first discard period timer 304 expires, the UE 102 discards 440a the data units. Each PSI may have the same or a different first discard time period 304. Alternatively, the same first discard period timer 304 is used for any PSI level, and if the UE 102 does not transmit the data unit before the first discard period timer 304 expires, the UE 102 discards 440a the data unit regardless of the PSI.

[0067] The network entity 104 measures 415b a second network congestion level in order to determine whether to enable data unit discarding with a second discard time period to further alleviate the network congestion. The second discard time period 305 is shorter than the first discard time period 304. The network entity 104 determines 415b whether the network congestion level fulfills a threshold criterion. For example, the network entity 104 determines 415b whether the second network congestion level is above athreshold.

[0068] The network entity transmits 450 (e.g., via broadcast, unicast, or groupcast messaging), based on the data unit parameter report and the second network congestion level, a second indicator to the UE 102 to enable data unit discarding according to the second discard time period 305 (e.g., a delay budget associated with the second data unit). In this regard, the network entity transmits 450 the second indicator via DCI. a MAC-CE, an RRC message, or other suitable communication. The second indicator may indicate the second discard time period 305 value, a scaling factor, and / or a PSI threshold.

[0069] The second discard time period 305 value indication may be an absolute time period, a relative time period (e.g., a scaling factor applied to the first discard time period 304), and / or an index to a second discard time period table stored at the UE 102. In some aspects, the UE 102 applies the scaling factor by dividing the first discard time period 304 by a multiple of the scaling factor, multiplying the first discard time period 304 by a multiple of the scaling factor, or subtracting a multiple of the scaling factor from the first discard time period 304. In some aspects, the network entity 104 transmits 450 the second indicator to the UE 102 without transmitting 420 the first indicator to the UE 102.

[0070] The UE 102 receives 430b data units in a transmit buffer from a higher layer (e.g., an application layer). For example, referring to FIG. 3A, the UE 102 receives 430b a second data unit in the transmit buffer at t7. The data units may include a PDU. a PDU Set. a PDU Set group, an SDU, a Data Burst and / or Data Burst group.

[0071] The UE 102 starts the second discard period timer 305 when the second data unit arrives in the transmit buffer (e.g., arrive from an upper layer or from an application) after receipt of the second indication. If the UE 102 does not transmit the second data unit before the second discard period timer 305 expires, the UE 102 discards 440b the second data unit with an indicated PSI or discards 440b the second data unit if there is no indicated PSI. Each PSI may have the same or a different second discard time period 305. Alternatively, the same second discard period timer 304 is used for any PSI level, and if the UE 102 does not transmit the second data unit before the second discard period timer 305 expires, the UE 102 discards 440b the second data unit regardless of the PSI.

[0072] The network entity 104 determines 415c a third network congestion level in order to determine whether to disable data unit discarding for network congestion alleviation. The network entity 104 determines 415c whether the network congestion level fulfills a threshold criterion. For example, the network entity 104 determines 415c whether the network congestion level is below a threshold.

[0073] The network entity 104 optionally transmits 470 a third indicator to disable data unit discarding. The UE 102 continues to use the second discard time period T5 305 to start discard timer for new arriving data until the UE 102 receives 470 the third indicator from the network entity 104 directing the UE 102 to refrain 480 from data unit discarding. For example, when the network entity 104 determines 415c that the network congestion has dropped below the network congestion threshold, the network entity 104 transmits 470 (e.g., via RRC, MAC- CE, or DCI) the third indicator to the UE 102 to disable data unit discarding.

[0074] FIG. 5 is a signaling diagram of a method 500 illustrating communications between a UE 102 and a network entity 104 for discarding data units according to an embodiment in a wireless communications system as shown in FIGs. 1-2. The signaling diagram of FIG. 5 corresponds to the timing diagram of FIG. 3B in which the network entity 104 transmits a first indicator to the UE 102 to enable data unit discarding according to a first discard timer and the UE switches to a second discard timer to discard the data units. In FIGs. 4 and 5, like reference numbers refer to like actions.

[0075] FIG. 5 describes discarding data units based on first and second discard timers similar to FIG. 4. However, in FIG. 5, the network entity 104 does not transmit a second indicator to the UE 102. Instead, the UE 102 begins discarding data units based on the second discard time period 305 after determining 555 expiry of the first time window T6. The UE 102 receives 420 a single indicator from the network entity 104 for the UE 102 to apply a first discard time period 304 to data units arriving in the buffer during a first time window and apply a second discard time period 305 to data units arriving in the buffer after the first time window. The network entity configures the length of the first time window.

[0076] FIG. 6 is a flowchart 600 of a method of wireless communication at a UE 102 according to an embodiment with a first discard time period and a second discard time period. The UE 102 transmits 605 a data unit parameter report to the network entity7104. In this regard, the UE 102 transmits 605 the data unit parameter report to the network entity' 104 using an RRC message, a MAC-CE, a SDAP control PDU, a PDCP control PDU, an RLC control PDU, or other suitable communication. The data unit parameter report includes several parameters for each data unit type (e.g., PDU Set Type). For example, the parameters include data rate, data rate range, PSI, data modality' (e.g., single-modal data or multi-modal data), data volume, and / or data volume range in the UE 102 transmit buffer.

[0077] The UE 102 receives 610 a data unit discarding configuration from the network entity7104. The data unit discarding configuration indicates the first discard time period value,a table of second discard time period values for a plurality of PSIs, a table of scaling factors for the plurality of PSIs, a table of second discard time period values, a table of scaling factors, a PSI group indicator, and / or a PSI group threshold.

[0078] The UE 102 receives 620 (e.g., via broadcast, unicast, or groupcast messaging), based on the data unit parameter report and the network congestion level, a first indicator from the network entity 104 to enable data unit discarding according to the first discard time period (e.g., a delay budget associated with the first data unit). The first indicator may indicate the first discard time period and / or a PSI threshold.

[0079] The UE 102 starts 635 the first discard period timer when the first data unit arrives in the transmit buffer (e.g., arrive from an upper layer or from an application). If the UE 102 does not transmit the first data unit before the first discard period timer expires, the UE 102 discards 640a the first data unit with an indicated PSI or discards 640a the first data unit directly if no PSI is indicated.

[0080] If the UE 102 does not receive 650 a second indicator or the UE does not receive670a a third indicator, the UE 102 continues to discard 640a data units based on the first discard timer. If the UE 102 receives 670a the third indicator, the UE 102 refrains 680 from discarding data units.

[0081] If the UE 102 receives 650 a second indicator, the UE 102 determines 655 the second discard timer and begins discarding 640b the second data unit based on the second discard timer. The UE 102 determines the second discard timer value based on the second indicator contents, a configuration received 610 from the network entity 104, or the UE 102 applies a predetermined scaling factor to the first discard timer.

[0082] If the UE 102 does not receive 670b a third indicator, the UE 102 continues to discard data units based on the second discard timer. If the UE 102 receives 670b the third indicator, the UE 102 refrains 680 from discarding data units.

[0083] FIG. 7 is a flowchart 700 of a method of wireless communication at a network entity 104 according to an embodiment with a first discard time period and a second discard time period. The network entity receives 705 a data unit parameter report from the UE 102. In this regard, the network entity7receives 705 the data unit parameter report from the UE 102 using an RRC message, a MAC-CE, a SDAP control PDU, a PDCP control PDU, an RLC control PDU. or other suitable communication. The data unit parameter report includes several parameters for each data unit type (e.g.. PDU Set Type). For example, the parameters includedata rate, data rate range. PSI, data modality (e.g., single-modal data or multi-modal data), data volume, and / or data volume range in the UE 102 transmit buffer.

[0084] The network entity 104 transmits 710 a data unit discarding configuration to the UE 102. The data unit discarding configuration indicates the first discard time period value, a table of second discard time period values for a plurality of PSIs, a table of scaling factors for the plurality of PSIs, a table of second discard time period values, a table of scaling factors, a PSI group indicator, and / or a PSI group threshold.

[0085] If the network entity 104 determines 715a that a network congestion level fulfills a threshold criterion (e.g., congestion level greater than a first threshold), the network entity 104 selects 717 UE(s) 102 for data unit discarding.

[0086] The network entity 104 transmits 720 (e.g., via broadcast, unicast, or groupcast messaging), based on the data unit parameter report and the network congestion level, a first indicator to the UE(s) 102 to enable data unit discarding according to the first discard time period (e g., a delay budget associated with the first data unit). The first indicator may indicate the first discard time period.

[0087] If the network entity’ 104 determines 715b that a network congestion level fulfills a threshold criterion (e.g., congestion level greater than a first threshold or a second threshold), the network entity 104 transmits 750 a second indicator to the UE 102 to enable data unit discarding according to the second discard time period.

[0088] If the network entity' 104 determines 715c that a network congestion level fulfills a threshold criterion (e.g., congestion level less than a first threshold or a second threshold), the network entity 104 transmits 770 a third indicator to the UE 102 to disable data unit discarding.

[0089] FIGs. 2-7 illustrate discarding data units to alleviate network congestion. FIGs. 8 and 9 show methods for implementing one or more aspects of FIGs. 2-7. In particular, FIG. 8 shows an implementation by the UE 102 of the one or more aspects of FIGs. 2-7. FIG. 9 shows an implementation by the network entity 104 of the one or more aspects of FIGs. 2-7.

[0090] FIG. 8 is a flowchart 800 of a method of wireless communication at a UE. With reference to FIGs. 2-6 and 10, the method may be performed by the UE 102 or 1002.

[0091] The UE 102 transmits 805, to a network entity 104, a data unit parameter report indicating a volume of data per data unit, a modality of the data unit, a PSI of the data unit, a BSR. a DSR. and / or a data rate of the data unit. For example, referring to FIGs. 4. 5, and 6, UE 102 transmits 405, 605, to the network entity 104, a data unit parameter report.

[0092] The UE 102 receives 810, from the network entity 104, a data unit discarding configuration indicating first and second discard time periods, scaling factor(s), a PSI group threshold and / or a PSI group indicator. For example, referring to FIGs. 4, 5, and 6, UE 102 receives 410, 610, from the network entity 104, a data unit discarding configuration.

[0093] The UE 102 receives 820, from the network entity 104, a first indicator to enable discarding a first data unit according to a first discard time period. For example, referring to FIGs. 4, 5, and 6, UE 102 receives 420, 620, from the network entity 104, a first indicator to enable discarding a first data unit with an indicated PSI according to a first discard time period.

[0094] The UE 102 discards 840a a first data unit after expiration of a first discard time period. For example, referring to FIGs. 4, 5. and 6, the UE 102 discards 440a, 640a a first data unit after expiration of a first discard time period.

[0095] The UE 102 receives 850, from the network entity 104, a second indicator to enable data unit discarding according to a second discard time period. For example, referring to FIGs. 4, 5, and 6. the UE 102 receives 450, 650, from the network entity 104, a second indicator to enable data unit discarding according to a second discard time period.

[0096] The UE 102 discards 840b a second data unit after expiration of a second discard time period. For example, referring to FIGs. 4, 5, and 6, UE 102 discards 440b, 640b a second data unit after expiration of a second discard time period.

[0097] The UE 102 optionally receives 870, from the network entity 104, a third indicator to disable data unit discarding. For example, referring to FIGs. 4, 5, and 6, the UE 102 optionally receives 470, 870, from the network entity 104, a third indicator to disable data unit discarding.

[0098] The UE 102 refrains 880. from data unit discarding based on receiving the third indicator. For example, referring to FIGs. 4, 5, and 6, the UE 102 refrains 480, 680 from data unit discarding based on receiving the third indicator.

[0099] FIG. 8 describes a method from a UE-side of a wireless communication link, whereas FIG. 9 describes a method from a network-side of the wireless communication link. A UE apparatus 1002, as described in FIG. 10, may perform the method of flowchart 800. The one or more network entities 104, as described in FIG. 11, may perform the method of flowchart 900.

[0100] FIG. 9 is a flowchart 900 of a method of wireless communication at a network entity. With reference to FIGs. 2-5, 7. and 11, the method may be performed by one or morenetwork entities 104. which may correspond to a base station or a unit of the base station, such as the RU 106, the DU 108, and / or the CU 110.

[0101] The network entity 104 receives 905, from a UE 102, a data unit parameter report indicating an amount of data per data unit, a modality of the data unit, a PSI of the data unit, a BSR. a DSR. and / or a data rate of the data unit. For example, referring to FIGs. 4, 5, and 7, the network entity 104 receives 405, 705, from a UE 102, a data unit parameter report.

[0102] The network entity 104 transmits 910, to the UE 102 a data unit discarding configuration including first and second discard time periods, scaling factor(s), a PSI group threshold, and / or aPSI group indicator. For example, referring to FIGs. 4, 5. and 7, the network entity 104 transmits 410. 710, to the UE 102 a data unit discarding configuration.

[0103] The network entity 104 determines 915 a network congestion level based on an indication of data volume of data units associated with the UE 102. For example, referring to FIGs. 4, 5, and 7, network entity 104 measures 415, 715, a network congestion level based on an indication of data volume of data units associated with the UE 102.

[0104] The network entity 104 transmits 920, to the UE 102 based on a network congestion level, a first indicator to enable data unit discarding according to a first discard time period. For example, referring to FIGs. 4, 5, and 7, the netw ork entity 104 transmits 420, 720, to the UE 102 based on a network congestion level, a first indicator to enable data unit discarding according to a first discard time period.

[0105] The network entity 104 transmits 950, to the UE 102 based on a change in the network congestion level, a second indicator to enable data unit discarding according to a second discard time period. For example, referring to FIGs. 4, 5, and 7, the network entity 104 transmits 450, 750. to the UE 102 based on a change in the network congestion level, a second indicator to enable data unit discarding according to a second discard time period.

[0106] The network entity 104 optionally transmits 970, to the UE 102, a third indicator to disable data unit discarding. For example, referring to FIGs. 4. 5, and 7, the network entity 104 optionally transmits 470, 770. to the UE 102. a third indicator to disable data unit discarding.

[0107] FIG. 10 is a diagram 1000 illustrating an example of a hardware implementation for a UE apparatus 1002. The UE apparatus 1002 may be the UE 102, a component of the UE 102, or may implement UE functionality. The UE apparatus 1002 may include an application processor 1006, which may have on-chip memory 1006’. In examples, the application processor 1006 may be coupled to a secure digital (SD) card 1008 and / or a display 1010. Theapplication processor 1006 may also be coupled to a sensor(s) module 1012, a power supply 1014, an additional module of memory 1016, a camera 1018, and / or other related components. For example, the sensor(s) module 1012 may control a barometric pressure sensor / altimeter, a motion sensor such as an inertial management unit (IMU), a gyroscope, accelerometer(s), a light detection and ranging (LIDAR) device, a radio-assisted detection and ranging (RADAR) device, a sound navigation and ranging (SONAR) device, a magnetometer, an audio device, and / or other technologies used for positioning.

[0108] The UE apparatus 1002 may further include a wireless baseband processor 1026, which may be referred to as a modem. The wireless baseband processor 1026 may have on- chip memory 1026'. Along with, and similar to, the application processor 1006, the wireless baseband processor 1026 may also be coupled to the sensor(s) module 1012, the power supply 1014, the additional module of memory71016, the camera 1018, and / or other related components. The wireless baseband processor 1026 may be additionally coupled to one or more subscriber identity module (SIM) card(s) 1020 and / or one or more transceivers 1030 (e.g., wireless RF transceivers).

[0109] Within the one or more transceivers 1030, the UE apparatus 1002 may include a Bluetooth module 1032, a WLAN module 1034, an SPS module 1036 (e.g., GNSS module), and / or a cellular module 1038. The Bluetooth module 1032. the WLAN module 1034, the SPS module 1036, and the cellular module 1038 may each include an on-chip transceiver (TRX). or in some cases, just a transmitter (TX) or just a receiver (RX). The Bluetooth module 1032, the WLAN module 1034, the SPS module 1036, and the cellular module 1038 may each include dedicated antennas and / or utilize antennas 1040 for communication with one or more other nodes. For example, the UE apparatus 1002 can communicate through the transceiver(s) 1030 via the antennas 1040 with another UE (e.g., sidelink communication) and / or with a network entity 104 (e.g., uplink / downlink communication), where the network entity 104 may correspond to a base station or a unit of the base station, such as the RU 106, the DU 108, or the CU 110.

[0110] The wireless baseband processor 1026 and the application processor 1006 may each include a computer-readable medium / memory 1026', 1006', respectively. The additional module of memory71016 may also be considered a computer-readable medium / memory7. Each computer-readable medium / memory 1026', 1006', 1016 may be non-transitory. The wireless baseband processor 1026 and the application processor 1006 may each be responsible for general processing, including execution of software stored on the computer-readable medium / memory 1026', 1006'. 1016. The software, when executed by the wireless baseband processor 1026 / application processor 1006, causes the wireless baseband processor 1026 / application processor 1006 to perform the various functions described herein. The computer-readable medium / memory may also be used for storing data that is manipulated by the wireless baseband processor 1026 / application processor 1006 when executing the software. The wireless baseband processor 1026 / application processor 1006 may be a component of the UE 102. The UE apparatus 1002 may be a processor chip (e.g., modem and / or application) and include just the wireless baseband processor 1026 and / or the application processor 1006. In other examples, the UE apparatus 1002 may be the entire UE 102 and include the additional modules of the apparatus 1002.[OHl] As discussed in FIG. 1 and implemented with respect to FIG. 8, the data unit discard component 140 is configured to receive, from a network entity', a first indicator to enable discarding data units according to a first discard time period. The data unit discard component 140 is further configured to discard a first data unit after expiration of the first discard time period. The data unit discard component 140 is further configured to receive, from the network entity, a second indicator to enable the data unit discarding according to a second discard time period. The data unit discard component 140 is further configured to discard a second data unit after expiration of the second discard time period.

[0112] The data unit discard component 140 may be within the application processor 1006 (e g., at 140a), the wireless baseband processor 1026 (e.g., at 140b), or both the application processor 1006 and the wireless baseband processor 1026. The data unit discard component 140a- 140b may be one or more hardware components specifically configured to carry out the stated processes / algorithm, implemented by one or more processors configured to perform the stated processes / algorithm, stored within a computer-readable medium for implementation by the one or more processors, or a combination thereof.

[0113] FIG. 11 is a diagram 1100 illustrating an example of a hardware implementation for one or more network entities 104. The one or more network entities 104 may be a base station, a component of a base station, or may implement base station functionality. The one or more network entities 104 may include, or may correspond to, at least one of the RU 106, the DU, 108, or the CU 110. The CU 110 may include a CU processor 1146, which may have on- chip memory 1146'. In some aspects, the CU 110 may further include an additional module of memory 1156 and / or a communications interface 1148, both of which may be coupled to the CU processor 1146. The CU 110 can communicate with the DU 108 through a midhaul link162, such as an Fl interface between the communications interface 1148 of the CU 110 and a communications interface 1128 of the DU 108.

[0114] The DU 108 may include a DU processor 1126, which may have on-chip memory 1126'. In some aspects, the DU 108 may further include an additional module of memory 1136 and / or the communications interface 1128, both of which may be coupled to the DU processor 1126. The DU 108 can communicate with the RU 106 through a fronthaul link 160 between the communications interface 1128 of the DU 108 and a communications interface 1108 of the RU 106.

[0115] The RU 106 may include an RU processor 1106, which may have on-chip memory 1106'. In some aspects, the RU 106 may further include an additional module of memory 1116, the communications interface 1108, and one or more transceivers 1130, all of which may be coupled to the RU processor 1106. The RU 106 may further include antennas 1140, which may be coupled to the one or more transceivers 1130, such that the RU 106 can communicate through the one or more transceivers 1130 via the antennas 1140 with the UE 102.

[0116] The on-chip memory 1106', 1126', 1146' and the additional modules of memory 1116, 1136, 1156 may each be considered a computer-readable medium / memory. Each computer-readable medium / memory' may be non-transitory. Each of the processors 1106, 1126, 1146 is responsible for general processing, including execution of software stored on the computer-readable medium / memory. The software, when executed by the corresponding processor(s) 1106, 1126, 1146 causes the processor(s) 1106, 1126, 1146 to perform the various functions described herein. The computer-readable medium / memory' may also be used for storing data that is manipulated by the processor(s) 1106, 1126, 1146 when executing the software. In examples, the congestion control component 150 may’ sit at any of the one or more network entities 104, such as at the CU 110; both the CU 110 and the DU 108; each of the CU 110, the DU 108, and the RU 106; the DU 108; both the DU 108 and the RU 106; or the RU 106.

[0117] As discussed in FIG. 1 and implemented with respect to FIG. 9, the congestion control component 150 is configured to transmit, to a UE based on a network congestion level, a first indicator to enable first data unit discarding according to a first discard time period. The congestion control component 150 is further configured to transmit, to the UE based on a change in the network congestion level, a second indicator to enable second data unit discarding according to a second discard time period.

[0118] The congestion control component 150 may be within one or more processors of the one or more network entities 104, such as the RU processor 1106 (e.g., at 150a), the DU processor 1126 (e.g., at 150b), and / or the CU processor 1146 (e.g., at 150c). The congestion control component 150a-150c may be one or more hardware components specifically configured to carry out the stated processes / algorithm. implemented by one or more processors 1106, 1126, 1146 configured to perform the stated processes / algorithm, stored within a computer-readable medium for implementation by the one or more processors 1106, 1126, 1146, or a combination thereof.

[0119] The specific order or hierarchy of blocks in the processes and flowcharts disclosed herein is an illustration of example approaches. Hence, the specific order or hierarchy of blocks in the processes and flowcharts may be rearranged. Some blocks may also be combined or deleted. Dashed lines may indicate optional elements of the diagrams. The accompanying method claims present elements of the various blocks in an example order, and are not limited to the specific order or hierarchy presented in the claims, processes, and flowcharts.

[0120] The detailed description set forth herein describes various configurations in connection with the drawings and does not represent the only configurations in which the concepts described herein may be practiced. The detailed description includes specific details for the purpose of providing a thorough explanation of various concepts. However, these concepts may be practiced without these specific details. In some instances, well known structures and components are shown in block diagram form in order to avoid obscuring such concepts.

[0121] Aspects of wireless communication systems, such as telecommunication systems, are presented with reference to various apparatuses and methods. These apparatuses and methods are described in the following detailed description and are illustrated in the accompanying drawings by various blocks, components, circuits, processes, call flows, systems, algorithms, etc. (collectively referred to as ‘‘elements”). These elements may be implemented using electronic hardware, computer software, or combinations thereof. Whether such elements are implemented as hardware or software depends upon the particular application and design constraints imposed on the overall system.

[0122] An element, or any portion of an element, or any combination of elements may be implemented as a “processing system” that includes one or more processors. Examples of processors include microprocessors, microcontrollers, graphics processing units (GPUs), central processing units (CPUs), application processors, digital signal processors (DSPs),reduced instruction set computing (RISC) processors, systems-on-chip (SoC), baseband processors, field programmable gate arrays (FPGAs), programmable logic devices (PLDs), state machines, gated logic, discrete hardware circuits, and other similar hardware configured to perform the various functionality described throughout this disclosure. One or more processors in the processing system may execute software, which may be referred to as software, firmware, middleware, microcode, hardware description language, or otherwise. Software shall be construed broadly to mean instructions, instruction sets, code, code segments, program code, programs, subprograms, software components, applications, software applications, software packages, routines, subroutines, objects, executables, threads of execution, procedures, functions, or any combination thereof.

[0123] If the functionality described herein is implemented in software, the functions may be stored on, or encoded as, one or more instructions or code on a computer-readable medium, such as a non-transitory computer-readable storage medium. Computer-readable media includes computer storage media and can include a random-access memory (RAM), a readonly memory (ROM), an electrically erasable programmable ROM (EEPROM), optical disk storage, magnetic disk storage, other magnetic storage devices, combinations of these types of computer-readable media, or any other medium that can be used to store computer executable code in the form of instructions or data structures that can be accessed by a computer. Storage media may be any available media that can be accessed by a computer.

[0124] Aspects, implementations, and / or use cases described herein may be implemented across many differing platform types, devices, systems, shapes, sizes, and packaging arrangements. For example, the aspects, implementations, and / or use cases may come about via integrated chip implementations and other non-module-component based devices, such as end-user devices, vehicles, communication devices, computing devices, industrial equipment, retail / purchasing devices, medical devices, artificial intelligence (Al)-enabled devices, machine learning (ML)-enabled devices, etc. The aspects, implementations, and / or use cases may range from chip-level or modular components to non-modular or non-chip-level implementations, and further to aggregate, distributed, or original equipment manufacturer (OEM) devices or systems incorporating one or more techniques described herein.

[0125] Devices incorporating the aspects and features described herein may also include additional components and features for the implementation and practice of the claimed and described aspects and features. For example, transmission and reception of wireless signals necessarily includes a number of components for analog and digital purposes, such as hardwarecomponents, antennas, RF-chains. power amplifiers, modulators, buffers, processor(s), interleavers, adders / summers, etc. Techniques described herein may be practiced in a wide variety of devices, chip-level components, systems, distributed arrangements, aggregated or disaggregated components, end-user devices, etc., of varying configurations.

[0126] The description herein is provided to enable a person skilled in the art to practice the various aspects described herein. Various modifications to these aspects will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other aspects. Thus, the claims are not limited to the aspects described herein, but are to be interpreted in view of the full scope of the present disclosure consistent with the language of the claims.

[0127] Reference to an element in the singular does not mean “one and only one” unless specifically stated, but rather “one or more.” Terms such as “if,” “when,” and “while” do not imply an immediate temporal relationship or reaction. That is, these phrases, e.g., “when,” do not imply an immediate action in response to or during the occurrence of an action, but simply imply that if a condition is met then an action will occur, but without requiring a specific or immediate time constraint for the action to occur. The terms “may”, “might”, and “can”, as used in this disclosure, often carry certain connotations. For example, “may” refers to a permissible feature that may or may not occur, “might” refers to a feature that probably occurs, and “can” refers to a capability (e.g.. capable of). The phrase “For example” often carries a similar connotation to “may” and, therefore, “may” is sometimes excluded from sentences that include “for example” or other similar phrases.

[0128] Unless specifically stated otherwise, the term “some” refers to one or more. Combinations such as “at least one of A, B. or C” or “one or more of A, B, or C” include any combination of A, B, and / or C, such as A and B, A and C, B and C, or A and B and C, and may include multiples of A, multiples of B, and / or multiples of C, or may include A only, B only, or C only. Sets should be interpreted as a set of elements where the elements number one or more. Terms or articles such as “a”, “an”, and / or “the” may refer to one of an item, feature, element, etc., that the term or article precedes, or may refer to more than one of said item, feature, element, etc. that the term or article precedes. For example, the recitation “a widget” does not preclude reference to multiples of said widget, as “multiple widgets” necessarily includes “a widget”. Hence, the recitation “a widget” may be interpreted as “at least one widget” or. similarly, interpreted as “one or more widgets”.

[0129] Unless otherwise specifically indicated, ordinal terms such as “first” and “second” do not necessarily imply an order in time, sequence, numerical value, etc., but are used to distinguish between different instances of a term or phrase that follows each ordinal term. Reference numbers, as used in the specification and figures, are sometimes cross-referenced among drawings to denote same or similar features. A feature that is exactly the same in multiple drawings may be labeled with the same reference number in the multiple drawings. A feature that is similar among the multiple drawings, but not exactly the same, may be labeled with reference numbers that have different leading numbers, but have one or more of the same trailing numbers (e.g.. 206, 306, 406, etc., may refer to similar features in the drawings). Sometimes an “X” is used to universally denote multiple variations of a feature. For instance, “X06” can universally refer to all reference numbers that end in “06” (e.g., 206, 306, 406, etc.).

[0130] Structural and functional equivalents to elements of the various aspects described throughout this disclosure that are known or later come to be known to those of ordinary skill in the art are expressly incorporated herein by reference and are encompassed by the claims. The words “module,” “mechanism,” “element,” “device,” and the like may not be a substitute for the word “means.” As such, no claim element is to be construed as a means plus function unless the element is expressly recited using the phrase “means for.” As used herein, the phrase “based on” shall not be construed as a reference to a closed set of information, one or more conditions, one or more factors, or the like. In other words, the phrase “based on A”, where “A” may be information, a condition, a factor, or the like, shall be construed as “based at least on A” unless specifically recited differently.

[0131] The following examples are illustrative only and may be combined with other examples or teachings described herein, without limitation.

[0132] Example 1 is a method of wireless communication at a UE, including: receiving, from a network entity, a first indicator to enable discarding data units from a transmit buffer according to a first discard time period; discarding, from the transmit buffer, a first data unit after expiration of the first discard time period starting when the first data unit arrived at the transmit buffer; receiving, from the network entity, a second indicator to enable discarding data units from the transmit buffer according to a second discard time period having a different length than the first discard time period; and discarding, from the transmit buffer, a second data unit after expiration of the second discard time period starting when the second data unit arrived at the transmit buffer.

[0133] Example 2 may be combined with Example 1 and further includes receiving, from the network entity, a configuration for data unit discarding comprising at least one of: a first discard time period value; a second discard time period value; a table of first discard time period values for a plurality of PSIs; a table of second discard time period values for the plurality of PSIs; a table of scaling factors for the plurality of PSIs; a table of first discard time period values; a table of second discard time period values; a table of scaling factors; a PSI group indicator; or a PSI group threshold.

[0134] Example 3 may be combined with any of Examples 1-2 and includes that a data unit comprises at least one of: a PDU; a PDU Set; a PDU Set group; an SDU; a Data Burst; or a Data Burst group.

[0135] Example 4 may be combined with any of Examples 1-3 and includes that the second discard time period is shorter than the first discard time period.

[0136] Example 5 may be combined with any of Examples 1-4 and includes that the second discard time period is applied to the second data unit based on at least one of: the PSI of the second data unit; or a delay budget of the second data unit.

[0137] Example 6 may be combined with any of Examples 1-5 and includes that the second indicator indicates at least one of: the second discard time period value; an index of a table storing second discard time period values; a scaling factor; an index of a table of scaling factors; or a PSI threshold.

[0138] Example 7 may be combined with any of Examples 1-6 and further includes determining the second discard time period by applying a scaling factor to the first discard time period.

[0139] Example 8 may be combined with Example 7 and includes that the applying the scaling factor comprises at least one of: dividing the first discard time period by a multiple of the scaling factor; multiplying the first discard time period by a multiple of the scaling factor; or subtracting a multiple of the scaling factor from the first discard time period.

[0140] Example 9 may be combined with any of Examples 1-8 and further includes transmitting, to the network entity, a data unit parameter set comprising at least one of: a volume of data of a data unit; a volume range of the data unit; an indication that the data unit comprises single-modal data; an indication that the data unit comprises multi-modal data; a PSI of the data unit; a data rate of the data unit; or a data rate range of the data unit.

[0141] Example 10 may be combined with any of Examples 1-9 and further includes receiving, from the network entity, a third indicator to disable the data unit discarding.

[0142] Example 11 may be combined with any of Examples 1-10 and further includes receiving, from an application layer of the UE, the first data unit and the second data unit into a transmit buffer of the UE.

[0143] Example 12 may be combined with any of Examples 1-11 and includes that the receiving, the second indicator comprises: receiving the second indicator via DCI or a MAC- CE message.

[0144] Example 13 may be combined with any of Examples 1-12 and includes that the first data unit or the second data unit comprises at least one of: haptic data; pose data; video data; or audio data.

[0145] Example 14 may be combined with Example 13 and includes that the video data comprises at least one of: I-frame video data; P-frame video data; or B-frame video data.

[0146] Example 15 may be combined with Example 13 and includes that the first data unit or the second data unit comprises at least one of: video data having a first PSI; or video data having a second PSI.

[0147] Example 16 may be combined with any of Examples 1-15 and includes that the discarding the first data unit comprises: discarding the first data unit having a first PSI; and retaining, after expiration of the first discard time period, another data unit without the first PSI.

[0148] Example 17 may be combined with any of Examples 1-16 and further includes receiving discard cycle parameters indicating a first discard cycle time period and a second discard cycle time period, and includes that: the discarding the first data unit further includes: receiving the first data unit into a transmit buffer during the first discard cycle time period; and receiving a fourth data unit into the transmit buffer during the second discard cycle time period and retaining the fourth data unit after expiration of a first discard time period.

[0149] Example 18 may be combined with Example 17 and further includes discarding the fourth data unit after expiration of a legacy data unit discard time period.

[0150] Example 19 is a method of wireless communication performed by a network entity, the method including: transmitting, to a UE, based on a network congestion level, a first indicator to enable first data unit discarding according to a first discard time period starting when the first data unit arrived at the transmit buffer; and transmitting, to the UE based on a change in the network congestion level, a second indicator to enable discarding a second data unit according to a second discard time period having a different length than the first discard time period, starting when the second data unit arrived at the transmit buffer.

[0151] Example 20 may be combined with Example 19 and further includes determining to transmit the first indicator to the UE based on at least one of: a data rate of a data unit associated with a buffer of the UE; or a data volume of data units associated with the buffer of the UE. and includes that the buffer comprises at least one of: an SDAP buffer; a PDCP buffer; an RLC buffer: or a MAC buffer.

[0152] Example 21 may be combined with any of Examples 19-20 and further includes receiving, from the UE, a status report indicating data volume of data units associated with the UE, and includes that: the transmitting the first indicator comprises transmitting the first indicator based on the network congestion level being a total of the data volume from the UE above a first threshold; and the transmitting the second indicator comprises transmitting the second indicator based on the network congestion level being a total of the data volume from the UE above a second threshold.

[0153] Example 22 may be combined with Example 21 and includes that the status report comprises at least one of: a BSR; or a DSR.

[0154] Example 23 may be combined with any of Examples 19-22 and further includes receiving, from a core network, an indicator of the network congestion level and includes that: the transmitting the second indicator comprises transmitting the second indicator when the network congestion level satisfies a third threshold.

[0155] Example 24 may be combined with any of Examples 19-23 and further includes transmitting, to the UE, a configuration for data unit discarding comprising at least one of: a first discard time period value; a second discard time period value; a table of second discard time period values corresponding to a plurality of PSI; a table of first discard time period values for the plurality’ of PSIs; a table of scaling factors corresponding to the plurality ofPSIs; a table of first discard time period values; a table of second discard time period values; a table of scaling factors; a PSI group indicator; or a PSI group threshold.

[0156] Example 25 may be combined with any of Examples 19-24 and includes that the data unit comprises at least one of: a PDU; a PDU Set; a PDU Set group; an SDU; a Data Burst; or a Data Burst group.

[0157] Example 26 may be combined with any of Examples 19-25 and includes that the second discard time period is shorter than the first discard time period.

[0158] Example 27 may be combined with any of Examples 19-26 and includes that the second discard time period is based on at least one of: a PSI of the second data unit; or a delay budget of the second data unit.

[0159] Example 28 may be combined with any of Examples 19-27 and includes that the second indicator indicates at least one of: the second discard time period value; an index of a table storing second discard time period values; a scaling factor; an index of a table of scaling factors; or a PSI threshold.

[0160] Example 29 may be combined with any of Examples 19-28 and further includes receiving, from the UE, a parameter set comprising at least one of: a volume of data of a data unit; an indication that the data unit comprises single-modal data; an indication that the data unit comprises multi-modal data; a PSI of the data unit; a data rate of the data unit; or a data rate range of the data unit.

[0161] Example 30 may be combined with any of Examples 19-29 and further includes transmitting, to the UE based on the network congestion level, a third indicator to disable the data unit discarding.

[0162] Example 31 may be combined with any of Examples 19-30 and includes that the transmitting, the second indicator comprises transmitting the second indicator via DCI or a MAC-CE message.

[0163] Example 32 may be combined with any of Examples 19-31 and includes that the data unit comprises at least one of: haptic data; pose data; video data; or audio data.

[0164] Example 33 may be combined with Example 32 and includes that the video data comprises at least one of: 1-frame video data; P-frame video data; or B-frame video data.

[0165] Example 34 may be combined with any of Examples 19-33 and includes that the first indicator further enables first data unit discarding according to a PSI.

[0166] Example 35 is a method of wireless communication performed by a UE, the method comprising: receiving, from a network entity, a first indicator to enable discarding data units with an indicated PSI during a discard cycle having a first discard cycle time period and a second discard cycle time period; discarding, a first data unit received in a transmit buffer during the first discard cycle time period, after expiration of a first discard time period; and discarding, a fourth data unit received in the transmit buffer during the second discard cycle time period, after expiration of a legacy data unit discard time period that is longer than the first discard time period.

[0167] Example 36 is an apparatus for wireless communication for implementing a method as in any of Examples 1-35.

[0168] Example 37 is an apparatus for wireless communication including means for implementing a method as in any of Examples 1-35.

[0169] Example 38 is a non-transitory computer-readable medium storing computer executable code, the code when executed by a processor causes the processor to implement a method as in any of Examples 1-35.

Claims

CLAIMSWHAT IS CLAIMED IS:

1. A method of wireless communication performed by a user equipment, UE, (102) the method comprising: receiving (420), from a network entity (104), a first indicator to enable discarding data units from a transmit buffer according to a first discard time period; discarding (440a), from the transmit buffer, a first data unit after expiration of the first discard time period starting when the first data unit arrived at the transmit buffer; receiving (450), from the network entity (104), a second indicator to enable discarding data units from the transmit buffer according to a second discard time period having a different length than the first discard time period; and discarding (440b), from the transmit buffer, a second data unit after expiration of the second discard time period starting when the second data unit arrived at the transmit buffer.

2. The method of claim 1, further comprising: receiving (410), from the network entity (104), a configuration for data unit discarding comprising at least one of: a first discard time period value (304); a second discard time period value (305); a table of first discard time period values (304) for a plurality of protocol data unit, PDU, set importance, PSIs; a table of second discard time period values (305) for the plurality’ of PSIs; a table of scaling factors for the plurality’ of PSIs; a table of first discard time period values (304); a table of second discard time period values (305); a table of scaling factors; a PSI group indicator; or a PSI group threshold.

3. The method of any of claims 1 to 2, wherein a data unit comprises at least one of: a PDU; a PDU Set;a PDU Set group; a service data unit, SDU; a Data Burst; or a Data Burst group.

4. The method of any of claims 1 to 3, wherein the second discard time period (305) is shorter than the first discard time period (304).

5. The method of any of claims 1 to 4, wherein the second discard time period (305) is applied to the second data unit based on at least one of: the PSI of the second data unit; or a delay budget of the second data unit.

6. The method of any of claims 1 to 5, wherein the second indicator indicates at least one of: the second discard time period value (305); an index of a table storing second discard time period values (305); a scaling factor; an index of a table of scaling factors; or a PSI threshold.

7. The method of any of claims 1 to 6, further comprising: determining (455) the second discard time period (305) by applying a scaling factor to the first discard time period (304), wherein the applying the scaling factor comprises at least one of: dividing the first discard time period by a multiple of the scaling factor; multiplying the first discard time period by a multiple of the scaling factor; or subtracting a multiple of the scaling factor from the first discard time period.

8. The method of any of claims 1 to 7, further comprising: transmitting (405), to the network entity (104), a data unit parameter set comprising at least one of: a volume of data of a data unit; a volume range of the data unit; an indication that the data unit comprises single-modal data; an indication that the data unit comprises multi-modal data; a PSI of the data unit; a data rate of the data unit; or a data rate range of the data unit.

9. The method of any of claims 1 to 8, further comprising: receiving (470), from the network entity (104), a third indicator to disable the data unit discarding.

10. The method of any of claims 1 to 9, further comprising: receiving, from an application layer of the UE, the first data unit and the second data unit into a transmit buffer of the UE.

11. The method of any of claims 1 to 10, wherein the receiving (450), the second indicator comprises: receiving (450) the second indicator via downlink control information, DCI, or a medium access control -control element. MAC-CE, message.

12. The method of any of claims 1 to 11, wherein the discarding the first data unit comprises: discarding the first data unit having a first PSI; and retaining, after expiration of the first discard time period, another data unit without the first PSI.

13. A method of any of claims 1 to 12. further comprising: receiving discard cycle parameters indicating a first discard cycle time period and a second discard cycle time period,wherein: the discarding the first data unit further comprises: receiving the first data unit into a transmit buffer during the first discard cycle time period; and receiving a fourth data unit into the transmit buffer during the second discard cycle time period and retaining the fourth data unit after expiration of a first discard time period.

14. A method of wireless communication performed by a network entity (104), the method comprising: transmitting (420), to a user equipment, UE, (102) based on a netw ork congestion level, a first indicator to enable first data unit discarding according to a first discard time period starting when the first data unit arrived at the transmit buffer; and transmitting (450), to the UE (102) based on a change in the network congestion level, a second indicator to enable discarding a second data unit according to a second discard time period having a different length than the first discard time period, starting w hen the second data unit arrived at the transmit buffer.

15. An apparatus for wireless communication comprising a transceiver, a memory, and a processor coupled to the transceiver and the memory' and configured to implement a method as in any of claims 1-14.

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