DSR trigger for scheduling restrictions / measurement gaps

Abstract

A User Equipment, UE, configured to: perform a first determining of a start time and an end time of a first time window comprising at least a second time window with uplink scheduling restrictions; pe

Description

TECHNOLOGY

[0001] The present disclosure relates to uplink scheduling with delay status report, in particular to scheduling restrictions during uplink transmissions. BACKGROUND

[0002] Any discussion of the background art throughout the specification should in no way be considered as an admission that such art is widely known or forms part of common general knowledge in the field.

[0003] Delay Status Report (DSR) is introduced in Rel-18 to convey delay status information to the gNB, so that the gNB can perform delay-based packet scheduling (inter-UE) based on such information. With scheduling restriction enhancements currently under specifications in 3GPP Rel-19, the gNB may for example decide to indicate to the UE, based on e g. DSR, to skip an SSB measurement time configuration (SMTC) or a measurement gap (MG) for Radio Resource Management (RRM) measurements and prioritize PUSCH transmission, so that the Packet Delay Budget / PDU Set Delay Budget (PDB / PSDB) can be fulfilled. However, if the DSR cannot be transmitted because its transmission overlaps with an SMTC / MG, or even in case the DSR is transmitted too close to the start of the SMTC / MG, then the gNB does not have a chance to indicate to the UE to skip the SMTC / MG to prioritize the UL transmission. Therefore, the PDB / PSDB requirements may not be fulfilled.

[0004] An example of an overlapping MG with UL slots is depicted in Figure 1, wherein it is assumed numerology value of p=l (i.e., SCS = 30 kHz) and a DDDSU frame structure. Additionally, it is assumed a PDCP discard timer of 20 ms, which gives the UE at maximum 7 UL slots to transmit it before discarding occurs (i.e., the UL slot where the data arrives cannot be used to transmit it). However, in the example, it can be noticed that the UE only have four UL slots available for transmission of the packet due to the configuration of a MG with duration of 6ms (i.e., within the block with dashed frame in Figure 1). It means the resource availability has been reduced by approx. 43%. Therefore, if the data has not been transmitted after the first three UL slots (i.e., at the arrow immediately before the block with dashed frame in Figure 1), the UE will have one more attempt after the measurement gap occurs, which would not be sufficient for the UE to transmit the data before PDCP discard timer expires.

[0005] If a DSR trigger indicating to the gNB scheduler the presence of delay-critical data in the UE buffer is overlapping with the SMTC / MG window, or even happening too close to the start of the SMTC / MG window, it may prevent the gNB to indicating skipping of the SMTC / MG thus exceeding the PDB / PSDB.

[0006] In R2-2404426, it is proposed considering a DSR enhancement (e.g., allowance of earlier DSR triggering) to cover this issue, however without giving further details about the solution.

[0007] Hence, there is a need to propose a new mechanism to trigger a DSR that can avoid overlapping with scheduling instructions during uplink transmissions, e.g., scheduling instructions due to SMTC / MG. SUMMARY

[0008] In accordance with a first aspect of the present disclosure, there is provided a User Equipment, UE, comprising: at least one processor, and at least one memory storing instructions that, when executed by the at least one processor, cause the UE at least to: perform a first determining of a start time and an end time of a first time window comprising at least a second time window with uplink scheduling restrictions; perform a second determining of an estimated time for triggering a Delay Status Report, DSR based on a minimum remaining time for a Logical Channel, LCH, or a Logical Channel Group, LCG, and a remaining time threshold configured for triggering the DSR; if, based on the first determining and the second determining, the estimated time is within the first time window, adjust at least one of the minimum remaining time for the LCH or LCG and the remaining time threshold configured for triggering the DSR based on an amount corresponding to a difference between the estimated time for the triggering of the DSR and the start time of the first time window; and based on a comparison between adjusted values of the minimum remaining time for the LCH or LCG and the remaining time threshold, perform triggering of the DSR, so that the DSR is triggered earlier than or at the start of the first time window.

[0009] In some examples, the first time window and the second time window have a same start time and a same end time, and / or the start time of the first time window is before a start time of the second time window, and / or the end time of the first time window is after an end time of the second second window.

[0010] In some examples, the UE is further configured to determine a difference between start times and / or end times of the first time window and the second time window based on UE capability for skipping the uplink scheduling restrictions.

[0011] In some examples, the UE is further configured to increase a value of the remaining time threshold configured for triggering the DSR by said amount for adjusting.

[0012] In some examples, the UE is further configured to increase a value of the remaining time threshold configured for triggering the DSR to infinity.

[0013] In some examples, the UE is further configured to decrease a value of the minimum remaining time for the LCH or LCG by said amount for adjusting.

[0014] In some examples, the remaining time for the LCH or LCG refers to the smallest value of remaining times of running Packet Data Convergence Protocol, PDCP, discard Timers among all Service Data Units, SDUs that are buffered for the LCG or LCH and that have not been transmitted in any Medium Access Control, MAC, Protocol Data Unit, PDU and that have not been reported as data volume in a DSR MAC control element, CE.

[0015] In some examples, the remaining time threshold configured for triggering the DSR is a threshold on the minimum remaining time for the LCH or LCG, wherein a value of the remaining timethreshold for triggering the DSR corresponds to a pre-configured period of time until expiration of a PDCP discard timer corresponding to an SDU associated with uplink data, wherein when a value of the minimum remaining time for the LCH or LCG is equal to or smaller than a value of the remaining time threshold configured for triggering the DSR, the UE is configured to trigger the DSR.

[0016] In some examples, the second time window is associated with an SSB Measurement Time Configuration, SMTC, or a Measurement Gap, MG, for Radio Resource Management, RRM, measurements.

[0017] In accordance with a second aspect of the present disclosure, there is provided a system comprising a User Equipment, UE, according to any one of the first aspect and the related examples and a network node of a radio access network, wherein the network node and the UE are configured to establish a communication to each other, wherein the network node comprises: at least one processor, and at least one memory storing instructions that, when executed by the at least one processor, cause the network node at least to: receive the DSR from the UE; and if, based on the received DSR, the network node determines that there are insufficient radio resources for serving uplink data buffered at the UE within a period of time until the start time of the first time window: instruct the UE to skip the uplink scheduling restrictions.

[0018] In some examples, the network node is further configured to, for determining whether there are sufficient radio resources: at a time at which the determination in relation to radio resources is executed, select for the UE a scheduling configuration with the smallest expected delivery time, and evaluate a condition of whether the smallest expected delivery time is smaller than the period of time until the start time of the first time window; wherein if the network determines that the condition holds true: determine that there are sufficient radio resources for serving the UE within the period of time until the start time of the first time window.

[0019] In accordance with a third aspect of the present disclosure, there is provided a method of a User Equipment, UE, the method comprising: performing a first determining of a start time and an end time of a first time window comprising at least a second time window with uplink scheduling restrictions; performing a second determining of an estimated time for triggering a Delay Status Report, DSR based on a minimum remaining time for a Logical Channel, LCH, or a Logical Channel Group, LCG, and a remaining time threshold configured for triggering the DSR; if, based on the first determining and the second determining, the estimated time is within the first time window, adjusting at least one of the minimum remaining time for the LCH or LCG and the remaining time threshold configured for triggering the DSR based on an amount corresponding to a difference between the estimated time for the triggering of the DSR and the start time of the first time window; and based on a comparison between adjusted values of the minimum remaining time for the LCH or LCG and the remaining time threshold, performing triggering of the DSR, so that the DSR is triggered earlier than or at the start of the first time window.

[0020] In accordance with a fourth aspect of the present disclosure, there is provided a method of a system comprising a User Equipment, UE and a network node of a radio access network, wherein the network node and the UE are configured to establish a communication to each other, the method comprising the steps according to the third aspect performed by the UE, and the method further comprising the following steps performed by the network node: receiving the DSR from the UE; and if, based on the received DSR, the network node determines that there are insufficient radio resources for serving uplink data buffered at the UE within a period of time until the start time of the first time window: instructing the UE to skip the uplink scheduling restrictions.

[0021] In accordance with a fifth aspect of the present disclosure, there is provided a computer program comprising instructions for causing an apparatus to perform the method according to the third aspect, or for causing an apparatus to perform the method according to the fourth aspect.

[0022] In accordance with a sixth aspect of the present disclosure, there is provided a memory storing computer readable instructions for causing an apparatus to perform the method according to the third aspect, or for causing an apparatus to perform the method according to the fourth aspect.

[0023] In addition, according to some other example embodiments, there is provided, for example, a computer program product for a wireless communication device comprising at least one processor, including software code portions for performing the respective steps disclosed in the present disclosure, when said product is run on the device. The computer program product may include a computer-readable medium on which said software code portions are stored. Furthermore, the computer program product may be directly loadable into the internal memory of the computer and / or transmittable via a network by means of at least one of upload, download and push procedures.

[0024] While some example embodiments will be described herein with particular reference to the above application, it will be appreciated that the present disclosure is not limited to such a field of use, and is applicable in broader contexts.

[0025] Notably, it is understood that methods according to the present disclosure relate to methods of operating the apparatuses according to the above example embodiments and variations thereof, and that respective statements made with regard to the apparatuses likewise apply to the corresponding methods, and vice versa, such that similar description may be omitted for the sake of conciseness. In addition, the above aspects may be combined in many ways, even if not explicitly disclosed. The skilled person will understand that these combinations of aspects and features / steps are possible unless it creates a contradiction which is explicitly excluded.

[0026] Implementations of the disclosed apparatuses may include using, but not limited to, one or more processor, one or more application specific integrated circuit (ASIC) and / or one or more field programmable gate array (FPGA). Implementations of the apparatus may also include using other conventional and / or customized hardware such as software programmable processors, such as graphics processing unit (GPU) processors.

[0027] Other and further example embodiments of the present disclosure will become apparent during the course of the following discussion and by reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Example embodiments of the disclosure will now be described, by way of example only, with reference to the accompanying drawings in which:

[0029] Figure 1 schematically illustrates an example of a measurement gap overlapping uplink slots;

[0030] Figure 2 schematically illustrates an example of impact of a measurement gap on delay-critical data transmission;

[0031] Figure 3 schematically illustrates an example of a timing diagram for adjusting Remaining Time Threshold according to an example embodiment of the present disclosure;

[0032] Figure 4 schematically illustrates an example of a method for adjusting Remaining Time Threshold according to an example embodiment of the present disclosure;

[0033] Figure 5 schematically illustrates an example of a timing diagram for adjusting Remaining Time according to an example embodiment of the present disclosure;

[0034] Figure 6 schematically illustrates an example of a timing diagram for a DSR trigger according to an example embodiment of the present disclosure;

[0035] Figure 7 schematically illustrates an example of a method for a DSR trigger according to an example embodiment of the present disclosure; and

[0036] Figure 8 schematically illustrates an example of a method for skipping a measurement gap according to an example embodiment of the present disclosure. DESCRIPTION OF EXAMPLE EMBODIMENTS

[0037] In the following, different exemplifying embodiments will be described using, as an example of a communication network to which examples of embodiments may be applied, a communication network architecture based on 3GPP standards for a communication network, such as a 5G / NR, without restricting the embodiments to such an architecture, however. It is apparent for a person skilled in the art that the embodiments may also be applied to other kinds of communication networks where mobile communication principles are integrated with a D2D (device-to-device) or V2X (vehicle to everything) configuration, such as SL (side link), e.g. Wi-Fi, worldwide interoperability for microwave access (WiMAX), Bluetooth®, personal communications services (PCS), ZigBee®, wideband code division multiple access (WCDMA), systems using ultra-wideband (UWB) technology, mobile ad-hoc networks (MANETs), wired access, etc. Furthermore, without loss of generality, the description of some examples of embodiments is related to a mobile communication network, but principles of the disclosure can be extended and applied to any other type of communication network, such as a wired communication network.

[0038] The following examples and embodiments are to be understood only as illustrative examples. Although the specification may refer to “an”, “one”, or “some” example(s) or embodiments) in several locations, this does not necessarily mean that each such reference is related to the same example(s) or embodiment(s), or that the feature only applies to a single example or embodiment. Single features of different embodiments may also be combined to provide other embodiments. Furthermore, terms like “comprising” and “including” should be understood as not limiting the described embodiments to consist of only those features that have been mentioned; such examples and embodiments may also contain features, structures, units, modules, etc., that have not been specifically mentioned.

[0039] A basic system architecture of a (tele)communication network including a mobile communication system where some examples of embodiments are applicable may include an architecture of one or more communication networks including wireless access network subsystem(s) and core network(s). Such an architecture may include one or more communication network control elements or functions, access network elements, radio access network elements, access service network gateways or base transceiver stations, such as a base station (BS), an access point (AP), a NodeB (NB), an eNB or a gNB, a distributed unit (DU) or a centralized / central unit (CU), which controls a respective coverage area or cell(s) and with which one or more communication stations such as communication elements or functions, like user devices or terminal devices, like a user equipment (UE), or another device having a similar function, such as a modem chipset, a chip, a module etc., which can also be part of a station, an element, a function or an application capable of conducting a communication, such as a UE, an element or function usable in a machine-to-machine communication architecture, or attached as a separate element to such an element, function or applicati on capable of conducting a communication, or the like, are capable to communicate via one or more channels via one or more communication beams for transmitting several types of data in a plurality of access domains. Furthermore, core network elements or network functions, such as gateway network elements / functions, mobility management entities, a mobile switching center, servers, databases and the like may be included.

[0040] The following description may provide further details of alternatives, modifications and variances: a gNB comprises e.g., a node providing NR user plane and control plane protocol terminations towards the UE, and connected via the NG interface to the 5GC, e.g., according to 3GPP TS 38.300 V16.6.0 (2021-06) section 3.2 incorporated by reference.

[0041] A gNB Central Unit (gNB-CU) comprises e.g., a logical node hosting e.g., RRC, SDAP and PDCP protocols of the gNB or RRC and PDCP protocols of the en-gNB that controls the operation of one or more gNB-DUs. The gNB-CU terminates the Fl interface connected with the gNB-DU.

[0042] A gNB Distributed Unit (gNB-DU) comprises e.g., a logical node hosting e g., RLC, MAC and PHY layers of the gNB or en-gNB, and its operation is partly controlled by the gNB-CU. One gNB-DU supports one or multiple cells. One cell is supported by only one gNB-DU. The gNB-DU terminates the Fl interface connected with the gNB-CU.

[0043] A gNB-CU-Control Plane (gNB-CU-CP) comprises e.g., a logical node hosting e.g., the RRC and the control plane part of the PDCP protocol of the gNB-CU for an en-gNB or a gNB. The gNB-CU-CP terminates the El interface connected with the gNB-CU-UP and the Fl-C interface connected with the gNB-DU.

[0044] A gNB-CU-User Plane (gNB-CU-UP) comprises e.g., a logical node hosting e.g., the user plane part of the PDCP protocol of the gNB-CU for an en-gNB, and the user plane part of the PDCP protocol and the SDAP protocol of the gNB-CU for a gNB. The gNB-CU-UP terminates the El interface connected with the gNB-CU-CP and the Fl-U interface connected with the gNB-DU, e.g., according to 3GPP TS 38.401 V16.6.0 (2021-07) section 3.1 incorporated by reference.

[0045] Different functional splits between the central and distributed unit are possible, e.g., called options: Option 1 (lA-like split): • The function split in this option is similar to the 1A architecture in DC. RRC is in the central unit. PDCP, RLC, MAC, physical layer and RF are in the distributed unit. Option 2 (3C-like split): • The function split in this option is similar to the 3C architecture in DC. RRC and PDCP are in the central unit. RLC, MAC, physical layer and RF are in the distributed unit. Option 3 (intra RLC split): • Low RLC (partial function of RLC), MAC, physical layer and RF are in the distributed unit. PDCP and high RLC (the other partial function of RLC) are in the central unit. Option 4 (RLC-MAC split): • MAC, physical layer and RF are in the distributed unit. PDCP and RLC are in the central unit. Or else, e.g., according to 3GPP TR 38.801 V14.0.0 (2017-03) section 11 incorporated by reference.

[0046] A gNB supports different protocol layers, e.g., Layer 1 (LI) - physical layer.

[0047] The layer 2 (L2) of NR is split into the following sublayers: Medium Access Control (MAC), Radio Link Control (RLC), Packet Data Convergence Protocol (PDCP) and Service Data Adaptation Protocol (SDAP), where e.g.: • The physical layer offers to the MAC sublayer transport channels; • The MAC sublayer offers to the RLC sublayer logical channels; • The RLC sublayer offers to the PDCP sublayer RLC channels; • The PDCP sublayer offers to the SDAP sublayer radio bearers; • The SDAP sublayer offers to 5GC QoS flows; • Comp, refers to header compression and Segm. To segmentation; • Control channels include (BCCH, PCCH).

[0048] Layer 3 (L3) includes e.g., Radio Resource Control (RRC), e.g., according to 3GPP TS 38.300 V16.6.0 (2021-06) section 6 incorporated by reference.

[0049] A RAN (Radio Access Network) node or network node like e.g. a gNB, base station, gNB CU or gNB DU or parts thereof may be implemented using e.g. an apparatus with at least one processor and / or at least one memory (with computer-readable instructions (computer program)) configured to support and / or provision and / or process CU and / or DU related functionality and / or features, and / or at least one protocol (sub-)layer of a RAN (Radio Access Network), e.g. layer 2 and / or layer 3.

[0050] The gNB CU and gNB DU parts may e.g., be co-located or physically separated. The gNB DU may even be split further, e.g., into two parts, e.g., one including processing equipment and one including an antenna. A Central Unit (CU) may also be called BBU / REC / RCC / C-RAN / V-RAN, O-RAN, or part thereof. A Distributed Unit (DU) may also be called RRH / RRU / RE / RU, or part thereof. Hereinafter, in various example embodiments of the present disclosure, the CU-CP (or more generically, the CU) may also be referred to as a (first) network node that supports at least one of central unit control plane functionality or a layer 3 protocol of a radio access network; and similarly, the DU may be referred to as a (second) network node that supports at least one of distributed unit functionality or the layer 2 protocol of the radio access network.

[0051] A gNB-DU supports one or multiple cells, and could thus serve as e.g., a serving cell for a user equipment (UE).

[0052] A user equipment (UE) may include a wireless or mobile device, an apparatus with a radio interface to interact with a RAN (Radio Access Network), a smartphone, an in-vehicle apparatus, an loT device, a M2M device, or else. Such UE or apparatus may comprise: at least one processor; and at least one memory including computer program code; wherein the at least one memory and the computer program code are configured to, with the at least one processor, cause the apparatus at least to perform certain operations, like e.g. RRC connection to the RAN. A UE is e.g., configured to generate a message (e.g., including a cell ID) to be transmitted via radio towards a RAN (e.g., to reach and communicate with a serving cell). A UE may generate and transmit and receive RRC messages containing one or more RRC PDUs (Packet Data Units).

[0053] The UE may have different states (e.g., according to 3GPP TS 38.331 V16.5.0 (2021-06) sections 42.1 and 4.4, incorporated by reference).

[0054] A UE is e.g., either in RRC ^CONNECTED state or in RRC IXACTIVE state when an RRC connection has been established.

[0055] In RRC CONNECTED state a UE may: • store the AS context; • transfer unicast data to / from the UE; • monitor control channels associated with the shared data channel to determine if data is scheduled for the data channel; • provide channel quality and feedback information; • perform neighboring cell measurements and measurement reporting.

[0056] The RRC protocol includes e.g. the following main functions: • RRC connection control; • measurement configuration and reporting; • establishment / modification / release of measurement configuration (e.g. intrafrequency, inter-frequency and inter-RAT measurements); • setup and release of measurement gaps; • measurement reporting.

[0057] The general functions and interconnections of the described elements and functions, which also depend on the actual network type, are known to those skilled in the art and described in corresponding specifications, so that a detailed description thereof may omitted herein for the sake of conciseness. However, it is to be noted that several additional network elements and signaling links may be employed for a communication to or from an element, function or application, like a communication endpoint, a communication network control element, such as a server, a gateway, a radio network controller, and other elements of the same or other communication networks besides those described in detail herein below.

[0058] A communication network architecture as being considered in examples of embodiments may also be able to communicate with other networks, such as a public switched telephone network or the Internet. The communication network may also be able to support the usage of cloud services for virtual network elements or functions thereof, wherein it is to be noted that the virtual network part of the telecommunication network can also be provided by non-cloud resources, e.g. an internal network or the like. It should be appreciated that network elements of an access system, of a core network etc., and / or respective functionalities may be implemented by using any node, host, server, access node or entity etc. being suitable for such a usage. Generally, a network function can be implemented either as a network element on a dedicated hardware, as a software instance running on a dedicated hardware, or as a virtualized function instantiated on an appropriate platform, e.g., a cloud infrastructure.

[0059] Furthermore, a network element, such as communication elements, like a UE, a terminal device, control elements or functions, such as access network elements, like a base station / BS, a gNB, a radio network controller, a core network control element or function, such as a gateway element, or other network elements or functions, as described herein, and any other elements, functions or applications may be implemented by software, e.g., by a computer program product for a computer, and / or by hardware. For executing their respective processing, correspondingly used devices, nodes, functions or network elements may include several means, modules, units, components, etc. (not shown) which are required for control, processing and / or communication / signaling functionality. Such means, modules, units and components may include, for example, one or more processors or processor units including one or more processing portions for executing instructions and / or programs and / or for processing data, storage or memory units or means for storing instructions, programs and / or data, for serving as a work area of the processor or processing portion and the like (e.g. ROM, RAM, EEPROM, and the like), input or interface means for inputting data and instructions by software (e.g. floppy disc, CD-ROM, EEPROM, and the like), a user interface for providing monitor and manipulation possibilities to a user (e.g. a screen, a keyboard and the like), other interface or means for establishing links and / or connections under the control of the processor unit or portion (e.g. wired and wireless interface means, radio interface means including e.g. an antenna unit or the like, means for forming a radio communication part etc.) and the like, wherein respective means forming an interface, such as a radio communication part, can be also located on a remote site (e.g. a radio head or a radio station etc.). It is to be noted that in the present specification processing portions should not be only considered to represent physical portions of one or more processors, but may also be considered as a logical division of the referred processing tasks performed by one or more processors. It should be appreciated that according to some examples, a so-called “liquid” or flexible network concept may be employed where the operations and functionalities of a network element, a network function, or of another entity of the network, may be performed in different entities or functions, such as in a node, host or server, in a flexible manner. In other words, a “division of labor” between involved network elements, functions or entities may vary case by case.

[0060] As illustrated above, the present disclosure generally seeks to provide a specific solution for addressing the issue where a DSR trigger / transmission (or trigger of the transmission of a DSR) relating to uplink data in the UE buffer overlaps with scheduling restrictions during the corresponding uplink transmissions.

[0061] Within the Rei. 19 XR Phase 3 objectives, among others, the following objectives 5 have been identified: • Specify enhancements to enable transmission / reception in gaps / restrictions that are caused by RRM measurements (from inter-frequency RRM measurement gaps, or intra-frequency measurements, or other scheduling restrictions etc). [RANI, RAN2, RAN4] o Specify the corresponding measurement gap and scheduling restriction to enable the identified enhancements with RRM performance impact taken into consideration, work being triggered by LS. [RAN4] • Specify Enhancements for Scheduling, as follows: o For the UL, Study and if justified, Specify enhancements using delay / deadline information, for support of UL scheduling to enable high XR capacity while meeting delay requirements / avoiding too late PDUs. [RAN2], NOTE: LCP implementation complexity need to be taken into account when evaluating solutions. NOTE: Check in RAN#105

[0062] Both refer to the need to improve scheduling - one in view of RRM measurements and the other in terms of UL scheduling, with DSR being one of the new options available to the gNB for that task. The present disclosure relates to the interaction between scheduling 10 restriction enhancements during RRM measurements and uplink scheduling enhancements in particular for improving DSR triggering and transmission. Current discussions in 3 GPP Rei. 19 XR Agenda Items

[0063] [R2-2402629] makes the following proposal: 15 “ ...Regarding how to define the delay critical data, e.g. whether to reuse the existing remaining time threshold or introduce a new threshold to determine the delay-critical data, could be further discussed. Furthermore, in case there is some scheduling restriction, e.g. due to MG, during the period of PDB / PSDB of a frame burst, the actual available time period(s) for transmission of the frame burst will be further reduced. In such case, the LCP parameters based on PDB / PSDB requirements may not be enough for the buffered data. The gNB has to allocate the radio resources to empty the UE buffer within the available period(s) that could be much shorter than the actual PDB / PSDB requirements.

[0064] Observation 3 The available time periodfor a UL transmission of a frame burst may be shorter than the PDB / PSDB requirements in case of scheduling restriction, e.g. due to MG in the period of PDB / PSDB, the LCP parameters can become not enough to empty the UE buffer.

[0065] Proposal 2 The scheduling enhancements on LCP (e.g. LCHpriority adaptation, rate restriction adjustments) could be considered as a potential solution for UL transmission of delay-critical data.

[0066] Proposal 3 FFS on how to define delay-critical data, e.g. whether to reuse the existing remaining time threshold or introduce a new threshold to determine the delay-critical data, whether / how to consider the scheduling restriction (e.g. due to MG)... ”

[0067] [R2-2404426] makes the following proposal: . .According the study scope, the impact from measurement gap should also be considered. Some measurement gap could be disabled if there is XR frame burst which needs to be transmitted in the time period of the measurement gap. However, as measurement gap is designed for the UE to perform mobility measurement, at least some of the measurement gap should be kept in order to monitor the candidate carrier / cells for mobility purposes. The measurement gap may overlap with the remaining time period of the delay-critical data (see Figure 2), which can result in the DSR report is delayed and / or no enough time for the gNB to schedule the UL transmissions for the delay-critical data.

[0068] Observation 8 There is high packet loss risk for the delay-critical data when the MG overlaps with the end part of the corresponding PDB / PSDB window.

[0069] Proposal 7 RAN2 consider the DSR triggering enhancement (e.g. allowance of earlier DSR triggering) when the measurement gap overlaps with PDB / PSDB window... ” Scheduling Restrictions

[0070] As per the current NR specifications, the network configures the UE with respect to when the UE measures RSRP from e.g. SSBs by means of RRC signaling of the so-called SMTC (see section 5.5.2.10 in 38.331). The time-resolution of SMTC is on subframe level, corresponding to 1 ms intervals. It should be noted that the SMTC only instructs the UE when (in time domain) it could / should measure RSRP, while it is left for UE implementation to decide exactly when to measure, and which antenna panel is to be used for conducting such measurement(s) during those measurement windows.

[0071] Scheduling restrictions that may apply to the UE during time-intervals where it may be performing RSRP measurements as per the SMTC configuration appear in 38.133, Section 9.5.6.3. In particular, for FR2 and Ll-RSRP on SSB, “The UE is not expected to transmit PUCCH / PUSCH / SRS or receive PDCCH / PDSCH / CSI-RS....”. A typical network configuration may use a setting with SMTC windows of 5 ms every 20 ms (aligned to the SSB periodicity), meaning that 25% of the time the UE cannot be scheduled, and its transmissions get delayed by up to 5ms, which corresponds to half the time of the packet delay budget (PDB) of AR / VR services. This poses serious scheduling restrictions that likely challenge the network’s capability to efficiently schedule and serve its XR users according to their QoS constraints, severely limiting the XR capacity if such scheduling restrictions are valid.

[0072] Therefore, 3GPP has agreed to specify solutions to reduce such scheduling restrictions by enabling the UE to prioritize PDCCH / PDSCH reception and / or PUSCH / PUCCH transmissions within an SMTC and / or a MG. Delay Status Report (DSR)

[0073] DSR was introduced in R.el.18 M.AC CE specification (TS 38.321). It is a new message used by the UE to inform the gNB about the data volume, in bytes, along with the corresponding smallest remaining time below a gNB configured threshold. This threshold is associated to the discard timer in PDCP. The discard timer is a parameter that allows discarding packets that would not fulfill the PDB such that time-frequency resources will not be wasted. Details are given below for context. 5.4.9 Delay status reporting The Delay Status Reporting (DSR) procedure is used to provide the serving gNB with delay status of LCGs. This delay status for an LCG includes remaining time, which is the smallest remaining value of the running PDCP discardTimers among SDUs that are buffered for the LCG but have not been transmitted in any MAC PDU as specified in clause 7.3 in TS 38.323 [4], and the total amount of delay-critical UL data for the LCG according to the data volume calculation procedure specified in clause 5.5 in TS 38.322 [3] and clause 5.6 in TS 38.323 [4] for the associated RLC and PDCP entities, respectively. RRC controls the DSR procedure by configuring the following parameter: remainingTimeThreshold, the threshold on remaining time for triggering a DSR for an LCG. If an LCG is configured for delay status reporting, the MAC entity shall: 1> if the smallest remaining value of the running PDCP discardTimers among all the SDUs buffered for the LCG that has not been transmitted in any MAC PDU and has not been reported as data volume in a DSR MAC CE becomes below remainingTimeThreshold of the LCG; and 1> if there is no DSR pending for the LCG: 2> trigger a DSR for the LCG. If there is at least one DSR pending, the MAC entity shall: 1 >if UL-SCH resources are available for a new transmission and the UL-SCH resources can accommodate the DSR MAC CE plus its subheader as a result of logical channel prioritization: 2> instruct the Multiplexing and Assembly procedure to generate the DSR MAC CE as specified in clause 6.1.3.72. 1> else if there is no pending SR already triggered by the DSR procedure for the same logical channel as of this DSR: 2> trigger a Scheduling Request. NOTE: The availability of UL-SCH resources for the transmission of the DSR MAC CE follows the same critieria specified in clause 5.4.5. An SDU is considered to be associated with a DSR if it has not been transmitted in any MAC PDU and it is associated with the LCG which triggered the DSR and the remaining value of its PDCP discardTimer is below remainingTimeThreshold. A MAC PDU shall contain at most one DSR MAC CE. The MAC entity shall not include a DSR MAC CE in a MAC PDU if the MAC PDU can accommodate the SDUs associated with all the pending DSRs. After a DSR is triggered, it is considered as pending until it is cancelled. The MAC entity shall cancel a pending DSR, either when all the SDUs associated with the DSR have been discarded, or when a MAC PDU is transmitted and this MAC PDU includes a DSR MAC CE that contains the delay information of all the SDUs associated with the DSR (as described in the clause 6.1.3.72). The MAC entity may cancel a pending DSR when a MAC PDU is transmitted and this MAC PDU includes all the SDUs associated with the DSR but is not sufficient to include the DSR MAC CE and its subheader.

[0074] In view of the above, it is proposed in accordance with the present disclousure that the UE dynamically modifies the value of the remaining time threshold (RT threshold) (or, alternatively, the value of the remaining time, RT, or the minimum remaining time) used for triggering the DSR based on at least one of the following: ■ The value of the remaining time RT ■ The time to the start of the next MG / SMTC with scheduling restrictions ■ The duration of the MG / SMTC ■ The configured RT threshold (remamingTimeThreshold)

[0075] With remaining time RT (also referred to as minimum remaining time) it is referred to the “smallest remaining value of the running PDCP discardTimers among all the SDUs buffered for a LCG (or LCH) that has not been transmitted in any MAC PDU and has not been reported as data volume in a DSR MAC CE” in MAC specifications, whose value is compared against remamingTimeThreshold to determine if a DSR should be triggered. Therein, the DSR, the RT, the RT threshold and the corresponding discard timer correspond to the same uplink data that arrives to the buffer. The SDUs are essentially the MAC SDUs that arrive from upper layers (i.e. PDCP and RLC) that need to be transmitted. More specifically, PDCP PDU is a RLC SDU and an RLC PDU is a MAC SDU and so on. Additionally, it is mentioned SDUs since at RLC segmentation occurs.

[0076] In the present disclosure, the terms “the remaining time, RT”, “the minimum remaining time” and “the minimum remaining time for the LCH or LCG” are used interchangeably, for simplicity purposes; and further, the terms “the remaining time threshold, RT threshold” and “the remaining time threshold configured for triggering of the DSR” are used interchangeably, for simplicity purposes.

[0077] More specifically, according to the present disclousure: 1) In one implementation option / alternative (Alt. 1), it is proposed to increase the value of the RT threshold (or alternatively reduce the value of the RT) used for triggering a DSR if the UE estimates that the DSR -without the proposed modifications- would be triggered within a time window comprising at least the MG / SMTC. The RT threshold is modified so that the DSR is triggered at the start of the time window. 2) In the second implementation option / alternative (Alt. 2), it is proposed to always trigger a DSR a certain amount of time (NW configured) prior to the start of a MG / SMTC. This could be implemented with a new DSR trigger, or by using the current DSR trigger and changing the value of the RT threshold (e.g., threshold is set to infinity) depending on the time to the start of the next MG / SMTC with scheduling restrictions.

[0078] References are now made to the figures. In particular, it is to be noted that identical or like reference numbers used in the figures of the present disclosure may, unless indicated otherwise, indicate identical or like elements, such that repeated description thereof may be omitted for reasons of conciseness. First Implementation Alternative / Option

[0079] For the first implementation option (Alt. 1), the value of the RT Threshold or the value of the RT changes dynamically. It covers two implementation sub-options as follows.

[0080] Sub-option la): RT corresponds to the smallest remaining value of the running PDCP discardTimers among SDUs that are buffered for the LCH or LCG but have not been transmitted in any MAC PDU (defined in TS 38.321, clause 5.4.9). THRESHOLD corresponds to the remainingTimeThreshold (i.e., the threshold on remaining time for triggering a DSR for an LCG). TMGS is the MG starting time. According to the present disclosure, it is proposed dynamic RT threshold as a function of time t THR(t). THR(t) changes when the UE estimates the DSR will be triggered within the MG duration.

[0081] Therein, RT(t) relates to the expiry of the discard timer, and t = 0 refers to the start of the discard timer. Each packet will have it’s own start of the discard timer depending on when it arrives in PDCP. Therefore, t=0 may refer to that the first packet goes out of the PDCP FIFO.

[0082] Further, the time t refers also to the time lapsed since the arrival of the data to the buffer that needs to be transmitted before the discard timer expired. Between the data arrival and discard timer, transmission (and retransmissions) take place. Therefore, the parameter t refers to any point of time between the data arrival and the discard timer expiration.

[0083] An example is depicted in Figure 3 that schematically illustrates a timing diagram according to the sub-option la for dynamic change / adaptation / adjustment of the RT threshold being a function of time.

[0084] According to the present discloure, first the UE determines, for a specific LCH or LCG, RT at time t RT(t), further, the UE performs the following steps: - Step S31: If RT(t) - THRESHOLD <0 - THR(t) = THRESHOLD - Step S32: Else If 0 <«T(t) - THRESHOLD <TMGs - t - THR(t) = THRESHOLD - Step S33: Else if TMGS - t <RT(t') - THRESHOLD <TMGe - t - THR(t) = THRESHOLD + [RT^ - THRESHOLD - ( TMGS - t)] - Step S34 Else if TMGe - t <RT(t) - THRESHOLD - THR(t) = THRESHOLD

[0085] Based on Step S33, it is proposed in accordance with the present disclosure that the value of the remaining time threshold to be used for DSR triggering is only changed / adjusted when the estimated time for DSR trigger falls within a specified time window which corresponds, in this specific example, to the MG / SMTC.

[0086] This example implemenration of method according to the present disclosure proposes to increase (dynamically) THR(t) if the UE estimates that the DSR would have been triggered within the MG duration. The threshold is increased by an amount (^^(t) — THRESHOLD — ( TMGS — t)) corresponding to the difference between the time when the DSR would have been triggered (i.e., the time marked with the vertical dashed line in Figure 3) and the start of the MG, TMGS. This means, the DSR is triggered exactly at the start of the MG with the proposed modification of the RT threshold.

[0087] Additionally or alternatively, it may be beneficial to add a (time) margin so that the DSR is not triggered at the exact point the MG starts. Instead, the DSR is triggered at least X ms prior to TMGS. In this case the abvove step S33 is modified as step S33a: - If TMGS -X-t< RT(t) - THRESHOLD <TMGe - t - THR(t) = THRESHOLD + [RT(t) - THRESHOLD - ( TMGS - t)] + X

[0088] Similarly, it may be beneficial to trigger the DSR transmission prior to the MG starts even if the UE estimates that the DSR would have been triggered within the first Y ms after end of the MG (i.e., TMGe). in which case the abvove step S33 is modified as Step S33b: - If TMGS -X-t< RT(t) - THRESHOLD <TMGe + Y-t - THR(t) = THRESHOLD + [RT(t) - THRESHOLD - ( TMGS - t)] + X

[0089] Numerical examples for the above proposed method are given in the following.

[0090] As a first numerical example, assume that a PDCP PDU arrives in the UE buffer at time t — 9 ms. The PDCP discard timer is set to 20 ms. At time t the remaining time is 11 ms. There is an MG with a duration of 6 ms that starts at TMGS = t + 8 ms and ends at TMGe = t + 14 ms. Further, the remaining time threshold is set to 5 ms, i.e., THRESHOLD = 5 ms.

[0091] At timet: RT(t) = 11 ms, RT(tj — THRESHOLD = 11ms — 5 ms = 6 ms, TMGS — t = 8 ms, and TMGe — t = 14 ms.

[0092] In the above example, since 0 <RT(t) — THRESHOLD <TMGS — t (i.e., 0 <6 ms <8 ms), THR(t) = THRESHOLD =5 ms. In this case, according to Step S32 it is not necessary to change THR(t).

[0093] As a second numerical example, assume that the MG with a duration of 6 ms starts at TMGS = t + 5 ms and ends at TMGe = t + 11 ms. The remaining time threshold is still set to 5 ms.

[0094] At timet: / ?(t) = 11 ms R(t) - THRESHOLD = Ums - 5 ms = 6 ms. TMGS — t = 5 ms. TMGe — t = 11 ms.

[0095] In the above example, since TMGS — t < / ?(t) — THRESHOLD <TMGe — t (i.e., 5 ms <6 ms <11 ms), then THR(t) = THRESHOLD + [RT(t) - THRESHOLD - ( TMGS - t)] = 5 ms + [11 ms — 5 ms — (5 ms)] = 6 ms

[0096] In this case, according to Step S33, THR(t) changes and the DSR is triggered when the minimum remaining time becomes smaller than 6 ms, i.e., exactly at the start of the measurement gap.

[0097] Figure 4 schematically illustrates a method according to the sub-option la for dynamic change / adaptation / adjustment of the RT threshold being a function of time.

[0098] At step S40: the UE determines the RT at time t -> RT(t).

[0099] At step S41: the UE determines according to sub-option la if TMGS — X — t< RT(t) — THRESHOLD <TMGe+ Y — t based on the above step S33b (or the UE determines the condition alternatively based on either of the above steps S33 and S33a).

[00100] At step S42: if the above condition in step S41 is determined to be true, the value of the remaining time threshold is adjusted based on any one of the above steps S33, S33a and S33b.

[00101] At step S43: Otherwise, if the above condition in step S41 is determined not to be true, the value of the remaining time threshold is kept unchanged, i.e. equal to the value which is configured by RRC (i.e., remainmgTimelhresM

[00102] At step S44, RT(t) is compared against the value of the remaining time threshold determined at step S42 or step S43, to determine if a DSR is to be triggered at step S45.

[00103] Sub-option lb): The purpose is to change RT when the UE estimates the DSR will be triggered within the MG duration. In this sub-option, it is proposed to define a dynamic RT as a function of time t RT'(t).

[00104] An example is depicted in Figure 5 that schematically illustrates a timing diagram according to the sub-option lb for dynamic change / adaptation / adjustment of the RT being a function of time.

[00105] According to the present discloure, first the UE determines RT at time t -> RT(t), and then performs the following steps: - Step S51: If RT(t) - THRESHOLD <0 - RT'^t') = RT(t) - Step S52: If 0 <RT(t) - THRESHOLD <TMGS - t - RT'^ = RT(t) - Step S53: Else if TMGS - t <RT(t) - THRESHOLD <TMGe - t - RT'^ = RT(t) - [RT^) - THRESHOLD - ( TMGS - £)] - Step S54: Else if TMGe - t <RT(t) - THRESHOLD - RT'(t) = RT(t)

[00106] Based on the above step S53, it is proposed in accordance with the present disclosure that the value of the remaining time, RT, to be used for DSR triggering is only changed / adjusted when the estimated time for DSR trigger falls within a specified time window which corresponds to the MG / SMTC.

[00107] According to the present disclosure, if the UE estimates that the DSR would have been triggered within the MG duration, RT'(t) is decreased such that a DSR could be triggered beforehand. The remaining time is decreased by an amount [RT(t) — THRESHOLD — ( TMGS — t)] corresponding to the difference between the time when the DSR would have been triggered (i.e., the time marked with the vertical dashed line in Figure 5) and the start of the MG. This means, the DSR is triggered exactly at the start of the MG with the proposed modification of the RT.

[00108] Additionally or alternatively, it may be beneficial to add a (time) margin so that the DSR is not triggered at the exact point the MG starts. Instead, the DSR is triggered at least X ms prior to TMGS. In this case the above step S53 is modified as S53a: - If TMGS -X-t< RT(t) - THRESHOLD <TMGe - t - RT'^t) = RT(t) - [RT(t) - THRESHOLD - ( TMGS - £)] - X

[00109] Similarly, it may be beneficial to trigger the DSR transmission prior to the MG starts even if the UE estimates that the DSR would have been triggered within the first Y ms after end of the MG (i.e., TMGe), in which case the above step S53 is modified as S53b: - If TMGS -X-t< RT(t) - THRESHOLD <TMGe + Y-t - RT'(t) = THRESHOLD - [RT(t) - THRESHOLD - ( TMGS - t)] - X

[00110] For sub-option lb, the same first numerical example is used as for sub-option la, with the following assumptions: • A PDCP PDU arrives in the UE buffer at time t — 9 ms. • The PDCP discard timer is 20 ms. • At time t the remaining time is 11 ms. • A MG, with a duration of 6 ms, starts at TMGS = t + 8 ms and ends at TMGe = t + 14 ms. • The remaining time threshold is set to 5 ms, i.e., THRESHOLD = 5 ms.

[00111] The above assumptions lead to the following results: RT(t) = 11 ms, RT(t) — THRESHOLD = 11 ms — Sms = 6 ms, TMGS — t = 8 ms, and TMGe — t = 14 ms.

[00112] In this example, since 0 <RT(t) — THRESHOLD <TMGS — t (0 <6 ms <8 ms), RT'(t) = RT = 11ms. In this case, according to the above step S52, it is not necessary to change RT'(t)

[00113] Further, for sub-option lb, the same second numerical example is also used as for sub-option la, wherein it is assumed that the MG with a duration of 6 ms starts at TMGS = t + 5 ms and ends at TMGe = t + 11 ms. The remaining time threshold is still set to 5 ms. This leads to the following results: R(t) = 11 ms R(t) — THRESHOLD = 11 ms — 5 ms = 6 ms. TMGS — t = 5 ms. TMGe — t = 11 ms.

[00114] In this example, since TMGS — t <R(t) — THRESHOLD <TMGe — t (5 ms <6 ms <11 ms), then RT'^t) = RT - [RT(t) - THRESHOLD - ( TMGS - t)] = 5 ms — [11 ms — 5 ms — (5 ms)] = 4 ms

[00115] In this case, RT'(t) changes / is adjusted and the DSRis triggered when the minimum remaining time becomes smaller than 5 ms, i.e., exactly at the start of the measurement gap. Second implementation option / alternative (Alt. 2)

[00116] For the second implementation option (Alt. 2), it is proposed in accordance with the present disclosure to introduce a new DSR trigger prior to the start of a MG / SMTC with scheduling restrictions. According to the present disclosure, the trigger occurs so that the DSR can be transmitted at the latest in the last UL slot available prior the MG / SMTC starts. The time between the start of the MG and the latest UL slot prior to the start of the MG is denoted as the minimum re-tuning time (f).

[00117] An example is depicted in Figure 6 that schematically illustrates a timing diagram according to the alternative Alt.2 for introducing a new DSR trigger based on a pre-configured time margin, e.g., a minimum re-tuning time. As shown in this Figure, it is proposed in accordance with Alt. 2 that at the determined time for triggering the DSR, the amount of time that remains before the start of the time window is at least equal to t'

[00118] According to the present disclosure, there are proposed two sub-options for introducing such a new DSR trigger e.g., in MAC specifications.

[00119] Implementation sub-option 2a) is to introduce a new DSR triggering mechanism (which may be in addition to the existing one based on remaining time). This could be implemented by using e.g., a DSR timer. The DSR timer is first set (at time t) to a value corresponding to (TMGSn — t) — T', where (TMGSn — t) is the time to the start of the next MG (MG #n) and T' is a network configured parameter. The parameter T' may be dependent on the UE capability related to UE timeline constraint for skipping a MG. This is because the DSR needs to be transmitted in time for the gNB to possibly indicate (based on the content of the DSR) to the UE to skip the next MG. Such skipping indication needs to be transmitted to the UE a minimum time prior to the start of the MG, depending on UE capability. Such minimum time may include e.g. the RF re-tuning time. Hence, the dependency of parameter T' on the UE capability. IfT' is properly dimensioned, the gNB can make sure that there is always at least one UL slot available to transmit the DSR prior to the start of the MG. - When the DSR timer expires, a DSR is triggered and the DSR timer is reset to (TMGSn+1 — t) — T', where (TMGSn+1 — t) — T', is the time to the start of the MG following the next MG (i.e., MG#w+l).

[00120] Implementation sub-option 2b): the existing DSR triggering based on remaining time threshold is modified so that DSR is always triggered a certain amount of time (T1) prior to a MG / SMTC with scheduling restrictions. In practice, this can be realized as a special case of the method according to sub-option la that modifies the value of the RT threshold, based on the following aspects: ■ The value of the remaining time RT ■ The time to the start of the next MG / SMTC with scheduling restrictions

[00121] More specifically, the method therefore proposed in accordance with sub-option 2b is illustrated in Figure 7, wherein the UE performs the following steps.

[00122] At step S70: the UE determines the RT at time t -> RTQty

[00123] At step S71: the UE determines according to sub-option 2b if the time to the start of the next MG / SMTC with scheduling restrictions is smaller or equal than the predefined value T', i.e. if (TMGs-t) <T'.

[00124] At step S72: if the above condition in step S71 is determined to be true, the value of the remaining time threshold is set to infinity.

[00125] At step S73: Otherwise, if the above condition in step S71 is determined not to be true, the value of the remaining time threshold is kept unchanged, i.e. equal to the value which is configured by RRC (i.e., remamingTimeThresholdy

[00126] According to the present disclosure, the UE may use a timer-based approach as the one proposed in implementation sub-option 2a to determine if this condition in step S71 is true, i.e. the condition is true if the DSR timer has expired.

[00127] At step S74, RT(t) is compared against the value of the remaining time threshold determined at step S72 or step S73, to determine if a DSR is to be triggered at step S75.

[00128] According to the present disclosure, after the UE performs adjustment of the minimum remaining time for the LCH or LCG and / or the remaining time threshold configured for triggering of the DSR, a comparison between the adjusted values of the minimum remaining time for the LCH or LCG and the remaining time threshold configured for triggering of the DSR is performed.

[00129] Therein, the comparison of adjusted values may include e.g. perform a third determining of an adjusted estimated time for triggering a Delay Status Report, DSR based on an adjusted minimum remaining time for a Logical Channel, LCH, or a Logical Channel Group, LCG, and / or an adjusted remaining time threshold configured for triggering the DSR, and a comparison of the actual time with the determined adjusted estimated time, and if both times are equal or within a time window, e.g. a (preconfigured) time margin, then the triggering is initiated. The (preconfigured) time margin may include a fix amount of time, or a flexible, e.g. last allocated UL time slot before start time of first time window, e.g. to enable receipt via DL of instruction of network to cancelling of planed measurements and re-use of measurement gap to transmit DSR. In addition, the adjustments of the parameters (remaining time (threshold)) could also be initiated if, based on the first determining and the second determining, the estimated time is within the first time window or a (preconfigured) time margin before the start time or a (preconfigured) time margin after the end time. The (preconfigured) time margin may include a fix amount of time, e.g. Y ms, or a flexible, e.g. time till next allocated UL time slot after end time of first time window, or last allocated UL time slot before start time of first time window. E.g. it may be beneficial to trigger the DSR transmission prior to the MG starts even if the UE estimates that the DSR would have been triggered within the first Y ms after end of theMG(i.e., ETMG2 _e). Network-side RRM method based on DSR

[00130] Upon reception of the DSR report sent by the UE, the network determines whether there are enough radio resources to serve the UE buffered data within the remaining time before the next measurement gap. If the network determines that it cannot successfully serve the UE before the next measurement gap, it sends an indication to skip the next measurement gap to the UE. The indication informs the UE to prioritize PDCCH reception and PUCCH transmission over RRM measurements during the next measurement gap.

[00131] Figure 8 illustrates the flowchart of the determination executed by the network.

[00132] At step S80, the network node recevices a DSR MAC CE from the UE.

[00133] At step S81, the network node determines whether there are enough radio resources to serve the UE buffered data within the remaining time before the next measurement gap.

[00134] At step S82, if the network node determines that there are enough radio resources to serve the UE buffered data within the remaining time before the next measurement gap, the network node proceeds to step S83, whereas if the network node determines that there are not enough radio resources to serve the UE buffered data within the remaining time before the next measurement gap, the network node proceeds to step S84.

[00135] At step S83, the network node schedules radio resources according to the resources determined in step S81.

[00136] At step S84, the network node sends to the UE an indication to skip the next measurement gap.

[00137] In one example, the determination S81 executed by the network is based on the following information: Latest BSR report; TDD frame stricture; Cell load in Uplink (UL): sum across all UEs in the cell of volume of data to be served in UL; Recent CSI and CQI reports; Recent Modulation and Coding Schemes (MCSs) assigned to the UE; - Number of retransmissions in UL; Recent UL MIMO configurations; Recent Power Control (PC) commands transmitted to the UE; Recent physical resource blocks (PRBs) allocated to the UE.

[00138] Additionally, the determination S81 executed by the network consists of the following steps: The network evaluates a plurality of scheduling configurations, wherein each configuration consists of a UL MCS, a UL MIMO configuration, and a UL transmission power assuming the same number of PRBs allocated to the UE in the last U slot where at least a PRB was allocated to the UE. Then, the network computes the expected delivery time of the UL data communicated in the last BSR report by the UE. As last step, the network selects the configuration with the smallest expected delivery time EDT(tp), where Id is the time at which the determination 102 is executed, and evaluates whether this time is smaller than the time to the next measurement gap Ip = TMGS — (i.e., the network evaluates if EDT(t^ <lD). If the condition holds true, then there are enough radio resources to serve the UE before the next MG.

[00139] In summary, it is proposed in accordance with the present disclosure a specific solution for triggering DSR, which avoids overlapping with scheduling restrictions that take place during the uplink transmission. Therein, the triggering of the DSR is based on the minimum remaining time and / or the remaining time threshold associated with the uplink data buffered at the UE; additionally or alternatively, the triggering of the DSR is based on a preconfigured time margin before a start time relating to uplink scheduling restrictions. Therein, the triggering of the DSR may be controlled by means of a DSR trigger timer.

[00140] It is noted that, although in the above-illustrated example embodiments (with reference to the figures), the messages communicated / exchanged between the network components / elements may appear to have specific / explicit names, depending on various implementations (e.g., the underlining technologies), these messages may have different names and / or be communicated / exchanged in different forms / formats, as can be understood and appreciated by the skilled person.

[00141] According to some example embodiments, there are also provided corresponding methods suitable to be carried out by the apparatuses (network elements / components) as described above, such as the UE, the CU, the DU, etc.

[00142] It should nevertheless be noted that the apparatus (device) features described above correspond to respective method features that may however not be explicitly described, for reasons of conciseness. The disclosure of the present document is considered to extend also to such method features. In particular, the present disclosure is understood to relate to methods of operating the devices described above, and / or to providing and / or arranging respective elements of these devices.

[00143] Further, according to some further example embodiments, there is also provided a respective apparatus (e.g., implementing the UE, the CU, the DU, etc., as described above) that comprises at least one processing circuitry, and at least one memory for storing instructions to be executed by the processing circuitry, wherein the at least one memory and the instructions are configured to, with the at least one processing circuitry, cause the respective apparatus to at least perform the respective steps as described above.

[00144] Yet in some other example embodiments, there is provided a respective apparatus (e.g., implementing the UE, the CU, the DU, etc., as described above) that comprises respective means configured to at least perform the respective steps as described above.

[00145] It is to be noted that examples of embodiments of the disclosure are applicable to various different network configurations. In other words, the examples shown in the above described figures, which are used as a basis for the above discussed examples, are only illustrative and do not limit the present disclosure in any way. That is, additional further existing and proposed new functionalities available in a corresponding operating environment may be used in connection with examples of embodiments of the disclosure based on the principles defined.

[00146] It should also to be noted that the disclosed example embodiments can be implemented in many ways using hardware and / or software configurations. For example, the disclosed embodiments may be implemented using dedicated hardware and / or hardware in association with software executable thereon. The components and / or elements in the figures are examples only and do not limit the scope of use or functionality of any hardware, software in combination with hardware, firmware, embedded logic component, or a combination of two or more such components implementing particular embodiments of the present disclosure.

[00147] It should further be noted that the description and drawings merely illustrate the principles of the present disclosure. Those skilled in the art will be able to implement various arrangements that, although not explicitly described or shown herein, embody the principles of the present disclosure and are included within its spirit and scope. Furthermore, all examples and embodiment outlined in the present disclosure are principally intended expressly to be only for explanatory purposes to help the reader in understanding the principles of the proposed method. Furthermore, all statements herein providing principles, aspects, and embodiments of the present disclosure, as well as specific examples thereof, are intended to encompass equivalents thereof. List of abbreviations: BSR: Buffer Status Report CQI: Channel Quality Indicator CSI: Channel State Information DSR: Delay Status Report LCH: Logical Channel MCS: Modulation and Coding Scheme MG: Measurement Gap NW: Network PC: Power Control RT: Remaining Time UE: User Equipment 5 UL: Uplink XR: Extended Reality 10

Claims

1. A User Equipment, UE, comprising:at least one processor, andat least one memory storing instructions that, when executed by the at least one processor, cause the UE at least to:perform a first determining of a start time and an end time of a first time window comprising at least a second time window with uplink scheduling restrictions;perform a second determining of an estimated time for triggering a Delay Status Report, DSR based on a minimum remaining time for a Logical Channel, LCH, or a Logical Channel Group, LCG, and a remaining time threshold configured for triggering the DSR;if, based on the first determining and the second determining, the estimated time is within the first time window, adjust at least one of the minimum remaining time for the LCH or LCG and the remaining time threshold configured for triggering the DSR based on an amount corresponding to a difference between the estimated time for the triggering of the DSR and the start time of the first time window; andbased on a comparison between adjusted values of the minimum remaining time for the LCH or LCG and the remaining time threshold, perform triggering of the DSR, so that the DSR is triggered earlier than or at the start of the first time window.

2. The UE according to claim 1, wherein the first time window and the second time window have a same start time and a same end time, and / or the start time of the first time window is before a start time of the second time window, and / or the end time of the first time window is after an end time of the second second window.

3. The UE according to claim 1 or claim 2, wherein the UE is further configured to determine a difference between start times and / or end times of the first time window and the second time window based on UE capability for skipping the uplink scheduling restrictions.

4. The UE according to any one of claims 1 to 3, wherein the UE is further configured to increase a value of the remaining time threshold configured for triggering the DSR by said amount for adjusting.

5. The UE according to any one of claims 1 to 4, wherein the UE is further configured to increase a value of the remaining time threshold configured for triggering the DSR to infinity.

6. The UE according to any one of claims 1 to 5, wherein the UE is further configured to decrease a value of the minimum remaining time for the LCH or LCG by said amount for adjusting.

7. The UE according to any one of claims 1 to 6, wherein the remaining time for the LCH or LCG refers to the smallest value of remaining times of running Packet Data Convergence Protocol, PDCP, discard Timers among all Service Data Units, SDUs that are buffered for the LCG or LCH and that have not been transmitted in any Medium Access Control, MAC, Protocol Data Unit, PDU and that have not been reported as data volume in a DSR MAC control element, CE.

8. The UE according to any one of claims 1 to 7, wherein the remaining time threshold configured for triggering the DSR is a threshold on the minimum remaining time for the LCH or LCG, wherein a value of the remaining time threshold for triggering the DSR corresponds to a pre-configured period of time until expiration of a PDCP discard timer corresponding to an SDU associated with uplink data, wherein when a value of the minimum remaining time for the LCH or LCG is equal to or smaller than a value of the remaining time threshold configured for triggering the DSR, the UE is configured to trigger the DSR.

9. The UE according to any one of claims 1 to 8, wherein the second time window is associated with an SSB Measurement Time Configuration, SMTC, or a Measurement Gap, MG, for Radio Resource Management, RRM, measurements.

10. A system comprising a User Equipment, UE, according to any one of claims 1 to 9 and a network node of a radio access network, wherein the network node and the UE are configured to establish a communication to each other, wherein the network node comprises: at least one processor, andat least one memory storing instructions that, when executed by the at least one processor, cause the network node at least to:receive the DSR from the UE; andif, based on the received DSR, the network node determines that there are insufficient radio resources for serving uplink data buffered at the UE within a period of time until the start time of the first time window:instruct the UE to skip the uplink scheduling restrictions.

11. The system according to claim 10, wherein the network node is further configured to, for determining whether there are sufficient radio resources:at a time at which the determination in relation to radio resources is executed, select for the UE a scheduling configuration with the smallest expected delivery time, and evaluate a condition of whether the smallest expected delivery time is smaller than the period of time until the start time of the first time window;wherein if the network determines that the condition holds true: determine that there are sufficient radio resources for serving the UE within the period of time until the start time of the first time window.

12. A method of a User Equipment, UE, the method comprising:performing a first determining of a start time and an end time of a first time window comprising at least a second time window with uplink scheduling restrictions;performing a second determining of an estimated time for triggering a Delay Status Report, DSR based on a minimum remaining time for a Logical Channel, LCH, or a Logical Channel Group, LCG, and a remaining time threshold configured for triggering the DSR;if, based on the first determining and the second determining, the estimated time is within the first time window, adjusting at least one of the minimum remaining time for the LCH or LCG and the remaining time threshold configured for triggering the DSR based on an amount corresponding to a difference between the estimated time for the triggering of the DSR and the start time of the first time window; andbased on a comparison between adjusted values of the minimum remaining time for the LCH or LCG and the remaining time threshold, performing triggering of the DSR, so that the DSR is triggered earlier than or at the start of the first time window.

13. A method of a system comprising a User Equipment, UE and a network node of a radio access network, wherein the network node and the UE are configured to establish a communication to each other, the method comprising the steps according to claim 16 performed by the UE, and the method further comprising the following steps performed by 5 the network node:receiving the DSR from the UE; andif, based on the received DSR, the network node determines that there are insufficient radio resources for serving uplink data buffered at the UE within a period of time until the start time of the first time window:10 instructing the UE to skip the uplink scheduling restrictions.

14. A computer program comprising instructions for causing an apparatus to perform the method according to claim 12 or claim 13.15 15. A memory storing computer readable instructions for causing an apparatus to perform themethod according to claim 12 or claim 13.

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