DSR trigger for scheduling restrictions / measurement gaps

Abstract

Described herein is 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: determine a start time and an end time of a first time window comprising at least a second time window with uplink scheduling restrictions; and if, based on the determining, a time that remains before the start time of the first time window is equal to or smaller than a pre-configured time margin, perform triggering of a Delay Status Report, DSR.

Description

DSR TRIGGER FOR SCHEDULING RESTRICTIONS / MEASUREMENT GAPS TECHNOLOGY

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

[0002] Any discussion of the background art throughout the specification should in no waybe 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 informationto 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 RadioResource Management (RRM) measurements and prioritize PUSCH transmission, so that thePacket Delay Budget / PDU Set Delay Budget (PDB / PSDB) can be fulfilled. However, if theDSR 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 itis assumed numerology value of μ=1 (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 7UL slots to transmit it before discarding occurs (i.e., the UL slot where the data arrives cannotbe 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 durationof 6ms (i.e., within the block with dashed frame in Figure 1). It means the resource availabilityhas been reduced by approx.43%. Therefore, if the data has not been transmitted after the firstthree 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 datain the UE buffer is overlapping with the SMTC / MG window, or even happening too close tothe 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 ofearlier DSR triggering) to cover this issue, however without giving further details about thesolution.

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

[0008] In accordance with a first aspect of the present disclosure, there is provided a UserEquipment, 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:determine a start time and an end time of a first time window comprising at least asecond time window with uplink scheduling restrictions; andif, based on the determining, a time that remains before the start time of the first timewindow is equal to or smaller than a pre-configured time margin, perform triggering of aDelay Status Report, DSR.

[0009] In some examples, the first time window and the second time window have a samestart 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 set a value of a DSR trigger timerto a difference between said time that remains before the start time of the first time window andthe pre-configured time margin, wherein when the DSR trigger timer expires, the UE is configured to trigger the DSR.

[0011] In some examples, after the DSR trigger timer associated with the first time windowexpires, the UE is further configured to set a value of the DSR trigger timer associated with anext time window that follows the first time window to a difference between a time that remainsbefore a start time of the next time window and the pre-configured time margin.

[0012] In some examples, if determining that said time that remains before the start time ofthe first time window is smaller than or equal to the pre-configured time margin, the UE isfurther configured to adjust a value of a remaining time threshold configured for triggering theDSR to infinity.

[0013] In some examples, if determining that said time that remains before the start time ofthe first time window is greater than the pre-configured time margin, the UE is configured tokeep a value of ^^^(^) of a remaining time threshold configured for triggering the DSR as apre-configured value.

[0014] In some examples, the UE is further configured to, based on a comparison betweenvalues of 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, perform triggering ofthe DSR..

[0015] In some examples, the pre-configured time margin is equal to or greater than a timedifference between the start time of the first time window and the last available uplink slot before the start time of the first time window.

[0016] In some examples, the UE is further configured to determine the pre-configured timemargin based on UE capability for skipping the uplink scheduling restrictions.

[0017] In some examples, the pre-configured time margin comprises a period of time for theDSR to be transmitted to a network node and a period of time for the network node to, inresponse to the received DSR, send to the UE an indication for skipping the uplink scheduling restrictions.

[0018] In some examples, the pre-configured time margin comprises a Radio Frequency, RF,re-tuning time.

[0019] In some examples, a remaining time threshold configured for triggering the DSR is athreshold on a minimum remaining time for a Logical Channel, LCH, or a Logical ChannelGroup, LCG for triggering the DSR, wherein a value of the remaining time threshold configuredfor triggering the DSR corresponds to a pre-configured period of time until expiration of aPacket Data Convergence Protocol, PDCP, discard timer corresponding to a Service Data Unit, SDU, associated with uplink data for which the DSR is to be triggered.

[0020] In some examples, a minimum remaining time for a Logical Channel, LCH, or aLogical Channel Group, LCG refers to the smallest value of remaining times of running PacketData Convergence Protocol, PDCP, discard Timers among all Service Data Units, SDUs thatare buffered for the LCG or LCH and that have not been transmitted in any Medium AccessControl, MAC, Protocol Data Unit, PDU and that have not been reported as data volume in aDSR MAC control element, CE.

[0021] In some examples, the second time window is associated with an SSB MeasurementTime Configuration, SMTC, or a Measurement Gap, MG, for the RRM measurements.

[0022] In accordance with a second aspect of the present disclosure, there is provided anetwork node of a radio access network, configured to establish a communication to a User Equipment, UE, the network node comprising: 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: transmit to the UE configuration information comprising a pre-configured time margin for the UE to perform triggering of a Delay Status Report, DSR, earlier than or at a starttime of a first time window comprising at least a second time window with uplinkscheduling restrictions.

[0023] In some examples, the network node is further configured to receive from the UE theDSR and if, based on the received DSR, the network node determines that there are insufficient radio resources for serving uplink data buffered at UE within a period of time that remainsbefore the start time of the first time window, the network node is further configured to instructthe UE to skip the uplink scheduling restrictions.

[0024] In some examples, the network node is further configured to, for determining whetherthere are sufficient radio resources: at a time at which the determination in relation to radio resources is executed, selectfor the UE a scheduling configuration with the smallest expected delivery time, andevaluate a condition of whether the smallest expected delivery time is smaller than theperiod of time that remains before the start time of the first time window;wherein if the network determines that the condition holds true: determine that thereare sufficient radio resources for serving the UE within the period of time that remainsbefore the start time of the first time window.

[0025] In accordance with a third aspect of the present disclosure, there is provided a methodof a User Equipment, UE, the method comprising:determining a start time and an end time of a first time window comprising at least asecond time window with uplink scheduling restrictions; andif, based on the determining, a time that remains before the start time of the first timewindow is equal to or smaller than a pre-configured time margin, performing triggeringof a Delay Status Report, DSR.

[0026] In accordance with a fourth aspect of the present disclosure, there is provided amethod of a network node of a radio access network, configured to establish a communication to a User Equipment, UE, the method comprising: transmitting to the UE configuration information comprising a pre-configured time margin for the UE to perform triggering of a Delay Status Report, DSR, earlier than orat a start time of a first time window comprising at least a second time window withuplink scheduling restrictions.

[0027] In accordance with a fifth aspect of the present disclosure, there is provided acomputer program comprising instructions for causing an apparatus to perform the methodaccording to the third aspect, or for causing an apparatus to perform the method according tothe fourth aspect.

[0028] In accordance with a sixth aspect of the present disclosure, there is provided amemory storing computer readable instructions for causing an apparatus to perform the methodaccording to the third aspect, or for causing an apparatus to perform the method according tothe fourth aspect.

[0029] In accordance with a seventh aspect of the present disclosure, there is provided a firstnetwork node that supports at least one of central unit control plane, CU-CP, functionality or a layer 3 protocol of a radio access network, comprising: at least one processor; and at least one memory storing instruction which, when executed by the at least one processor, cause the first network node at least to: establish a connection with a user equipment apparatus, UE, via a serving cell; andtransmit to the UE configuration information comprising a pre-configured time margin for the UE to perform triggering of a Delay Status Report, DSR, earlier than or at a starttime of a first time window comprising at least a second time window with uplinkscheduling restrictions.

[0030] In accordance with an eighth aspect of the present disclosure, there is provided asecond network node that supports at least one of the distributed unit, DU, functionality or a layer 2 protocol of a radio access network, and which supports a first cell, further comprising: at least one processor; and at least one memory storing instruction which, when executed by the at least one processor, cause the second network node at least to: establish a connection with a user equipment apparatus, UE, via the first cell acting asa serving cell; and transmit to the UE configuration information comprising a pre-configured time margin for the UE to perform triggering of a Delay Status Report, DSR, earlier than or at a starttime of a first time window comprising at least a second time window with uplinkscheduling restrictions.

[0031] In addition, according to some other example embodiments, there is provided, forexample, a computer program product for a wireless communication device comprising at leastone 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.

[0032] While some example embodiments will be described herein with particular referenceto the above application, it will be appreciated that the present disclosure is not limited to sucha field of use, and is applicable in broader contexts.

[0033] Notably, it is understood that methods according to the present disclosure relate tomethods of operating the apparatuses according to the above example embodiments andvariations thereof, and that respective statements made with regard to the apparatuses likewiseapply 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.

[0034] 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 ormore field programmable gate array (FPGA). Implementations of the apparatus may also include using other conventional and / or customized hardware such as software programmableprocessors, such as graphics processing unit (GPU) processors.

[0035] Other and further example embodiments of the present disclosure will becomeapparent during the course of the following discussion and by reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Example embodiments of the disclosure will now be described, by way of exampleonly, with reference to the accompanying drawings in which:

[0037] Figure 1 schematically illustrates an example of a measurement gap overlappinguplink slots;

[0038] Figure 2 schematically illustrates an example of impact of a measurement gap ondelay-critical data transmission;

[0039] Figure 3 schematically illustrates an example of a timing diagram for adjustingRemaining Time Threshold according to an example embodiment of the present disclosure;

[0040] Figure 4 schematically illustrates an example of a method for adjusting RemainingTime Threshold according to an example embodiment of the present disclosure;

[0041] Figure 5 schematically illustrates an example of a timing diagram for adjustingRemaining Time according to an example embodiment of the present disclosure;

[0042] Figure 6 schematically illustrates an example of a timing diagram for a DSR triggeraccording to an example embodiment of the present disclosure;

[0043] Figure 7 schematically illustrates an example of a method for a DSR trigger accordingto an example embodiment of the present disclosure; and

[0044] Figure 8 schematically illustrates an example of a method for skipping a measurementgap according to an example embodiment of the present disclosure.DESCRIPTION OF EXAMPLE EMBODIMENTS

[0045] In the following, different exemplifying embodiments will be described using, as anexample 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 kindsof 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.

[0046] The following examples and embodiments are to be understood only as illustrativeexamples. Although the specification may refer to “an”, “one”, or “some” example(s) or embodiment(s) 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.

[0047] A basic system architecture of a (tele)communication network including a mobilecommunication 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) ora centralized / central unit (CU), which controls a respective coverage area or cell(s) and withwhich 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 attachedas a separate element to such an element, function or applicati on capable of conducting acommunication, or the like, are capable to communicate via one or more channels via one ormore 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.

[0048] The following description may provide further details of alternatives, modificationsand variances: a gNB comprises e.g., a node providing NR user plane and control plane protocolterminations 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.

[0049] 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 F1 interface connected with the gNB-DU.

[0050] 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 F1 interface connected with the gNB-CU.

[0051] 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 E1 interface connected with the gNB-CU-UP and the F1-C interface connected with the gNB-DU.

[0052] A gNB-CU-User Plane (gNB-CU-UP) comprises e.g., a logical node hosting e.g., theuser 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 E1 interface connected with the gNB-CU-CP and the F1-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.

[0053] Different functional splits between the central and distributed unit are possible, e.g.,called options: Option 1 (1A-like split): ^The function split in this option is similar to the 1A architecture in DC. RRC isin 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 andPDCP 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 thedistributed 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 inthe central unit. Or else, e.g., according to 3GPP TR 38.801 V14.0.0 (2017-03) section 11 incorporated by reference.

[0054] A gNB supports different protocol layers, e.g., Layer 1 (L1) – physical layer.

[0055] 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).

[0056] Layer 3 (L3) includes e.g., Radio Resource Control (RRC), e.g., according to 3GPPTS 38.300 V16.6.0 (2021-06) section 6 incorporated by reference.

[0057] 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 (computerprogram)) configured to support and / or provision and / or process CU and / or DU relatedfunctionality 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.

[0058] The gNB CU and gNB DU parts may e.g., be co-located or physically separated. ThegNB DU may even be split further, e.g., into two parts, e.g., one including processing equipmentand 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 calledRRH / RRU / RE / RU, or part thereof. Hereinafter, in various example embodiments of the presentdisclosure, the CU-CP (or more generically, the CU) may also be referred to as a (first) networknode that supports at least one of central unit control plane functionality or a layer 3 protocolof a radio access network; and similarly, the DU may be referred to as a (second) network nodethat supports at least one of distributed unit functionality or the layer 2 protocol of the radioaccess network.

[0059] A gNB-DU supports one or multiple cells, and could thus serve as e.g., a serving cellfor a user equipment (UE).

[0060] A user equipment (UE) may include a wireless or mobile device, an apparatus with aradio interface to interact with a RAN (Radio Access Network), a smartphone, an in-vehicle apparatus, an IoT 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 viaradio towards a RAN (e.g., to reach and communicate with a serving cell). A UE may generateand transmit and receive RRC messages containing one or more RRC PDUs (Packet Data Units).

[0061] 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).

[0062] A UE is e.g., either in RRC_CONNECTED state or in RRC_INACTIVE state whenan RRC connection has been established.

[0063] 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 determineif data is scheduled for the data channel; ^provide channel quality and feedback information;^ perform neighboring cell measurements and measurement reporting.

[0064] 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. intra-frequency, inter-frequency and inter-RAT measurements); ^setup and release of measurement gaps;^ measurement reporting.

[0065] 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 omittedherein for the sake of conciseness. However, it is to be noted that several additional networkelements 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.

[0066] A communication network architecture as being considered in examples ofembodiments 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 benoted that the virtual network part of the telecommunication network can also be provided bynon-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.

[0067] Furthermore, a network element, such as communication elements, like a UE, aterminal 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, andany other elements, functions or applications may be implemented by software, e.g., by acomputer 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 andcomponents 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 ormeans for establishing links and / or connections under the control of the processor unit orportion (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.

[0068] As illustrated above, the present disclosure generally seeks to provide a specificsolution 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.

[0069] Within the Rel.19 XR Phase 3 objectives, among others, the following objectiveshave been identified: ^Specify enhancements to enable transmission / reception in gaps / restrictions thatare caused by RRM measurements (from inter-frequency RRM measurement gaps, or intra-frequency measurements, or other scheduling restrictions etc). [RAN1, RAN2, RAN4]o Specify the corresponding measurement gap and scheduling restriction toenable 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 usingdelay / 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

[0070] Both refer to the need to improve scheduling - one in view of RRM measurementsand the other in terms of UL scheduling, with DSR being one of the new options available tothe gNB for that task. The present disclosure relates to the interaction between schedulingrestriction enhancements during RRM measurements and uplink scheduling enhancements inparticular for improving DSR triggering and transmission.Current discussions in 3GPP Rel.19 XR Agenda Items

[0071] [R2-2402629] makes the following proposal:“…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.

[0072] Observation 3 The available time period for a UL transmission of a frame burst maybe 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.

[0073] Proposal 2 The scheduling enhancements on LCP (e.g. LCH priority adaptation,rate restriction adjustments) could be considered as a potential solution for UL transmission of delay-critical data.

[0074] Proposal 3 FFS on how to define delay-critical data, e.g. whether to reuse theexisting 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)...”

[0075] [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.

[0076] Observation 8 There is high packet loss risk for the delay-critical data when the MGoverlaps with the end part of the corresponding PDB / PSDB window.

[0077] Proposal 7 RAN2 consider the DSR triggering enhancement (e.g. allowance ofearlier DSR triggering) when the measurement gap overlaps with PDB / PSDB window…” Scheduling Restrictions

[0078] As per the current NR specifications, the network configures the UE with respect towhen 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.

[0079] Scheduling restrictions that may apply to the UE during time-intervals where it maybe performing RSRP measurements as per the SMTC configuration appear in 38.133, Section 9.5.6.3. In particular, for FR2 and L1-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 SSBperiodicity), 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.

[0080] Therefore, 3GPP has agreed to specify solutions to reduce such schedulingrestrictions 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)

[0081] DSR was introduced in Rel.18 MAC CE specification (TS 38.321). It is a newmessage 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 reportingThe 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 DSRfor 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 discardTimersamong all the SDUs buffered for the LCG that has not been transmitted in anyMAC PDU and has not been reported as data volume in a DSR MAC CE becomes below remainingTimeThreshold of the LCG; and1> 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 theDSR MAC CE as specified in clause 6.1.3.72. 1> else if there is no pending SR already triggered by the DSR procedure forthe 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 remainingvalue 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.

[0082] In view of the above, it is proposed in accordance with the present disclousure thatthe 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 (remainingTimeThreshold)

[0083] With remaining time RT (also referred to as minimum remaining time) it is referredto 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 comparedagainst remainingTimeThreshold 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 uplinkdata that arrives to the buffer. The SDUs are essentially the MAC SDUs that arrive from upperlayers (i.e. PDCP and RLC) that need to be transmitted. More specifically, PDCP PDU is aRLC SDU and an RLC PDU is a MAC SDU and so on. Additionally, it is mentioned SDUs since at RLC segmentation occurs.

[0084] In the present disclosure, the terms “the remaining time, RT”, “the minimumremaining 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.

[0085] More specifically, according to the present disclousure:1) In one implementation option / alternative (Alt. 1), it is proposed to increase thevalue 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 theMG / 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 alwaystrigger 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 thecurrent 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.

[0086] References are now made to the figures. In particular, it is to be noted that identicalor 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

[0087] For the first implementation option (Alt. 1), the value of the RT Threshold or thevalue of the RT changes dynamically. It covers two implementation sub-options as follows.

[0088] Sub-option 1a): ^^ corresponds to the smallest remaining value of the runningPDCP discardTimers among SDUs that are buffered for the LCH or LCG but have not beentransmitted in any MAC PDU (defined in TS 38.321, clause 5.4.9). ^^^^^^^^^ correspondsto the remainingTimeThreshold (i.e., the threshold on remaining time for triggering a DSR foran LCG). ^^^^ is the MG starting time. According to the present disclosure, it is proposeddynamic RT threshold as a function of time^^^(^). ^^^(^) changes when the UEestimates the DSR will be triggered within the MG duration.

[0089] Therein, RT(t) relates to the expiry of the discard timer, and ^ = ^ refers to the startof the discard timer. Each packet will have it’s own start of the discard timer depending onwhen it arrives in PDCP. Therefore, t=0 may refer to that the first packet goes out of the PDCPFIFO.

[0090] Further, the time ^ refers also to the time lapsed since the arrival of the data to thebuffer 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 ^refers to any point of time between the data arrival and the discard timer expiration.

[0091] An example is depicted in Figure 3 that schematically illustrates a timing diagramaccording to the sub-option 1a for dynamic change / adaptation / adjustment of the RTthreshold being a function of time.

[0092] According to the present discloure, first the UE determines, for a specific LCH orLCG, ^^ at time ^^^(^); further, the UE performs the following steps:- Step S31: If ^^(^) − ^^^^^^^^^ ≤ ^- ^^^(^) = ^^^^^^^^^- Step S32: Else If ^ < ^^(^) − ^^^^^^^^^ < ^^^^ − ^- ^^^(^) = ^^^^^^^^^- Step S33: Else if ^^^^ − ^ ≤ ^^(^) − ^^^^^^^^^ ≤ ^^^^ − ^- ^^^(^) = ^^^^^^^^^ + [^^(^) − ^^^^^^^^^ − ( ^^^^ − ^)]- Step S34 Else if ^^^^ − ^ < ^^(^) − ^^^^^^^^^- ^^^(^) = ^^^^^^^^^

[0093] Based on Step S33, it is proposed in accordance with the present disclosure that thevalue of the remaining time threshold to be used for DSR triggering is only changed / adjustedwhen the estimated time for DSR trigger falls within a specified time window which corresponds, in this specific example, to the MG / SMTC.

[0094] This example implemenration of method according to the present disclosure proposesto increase (dynamically) ^^^(^) if the UE estimates that the DSR would have been triggeredwithin the MG duration. The threshold is increased by an amount (^^(^) − ^^^^^^^^^ −( ^^^^ − ^)) corresponding to the difference between the time when the DSR would havebeen triggered (i.e., the time marked with the vertical dashed line in Figure 3) and the start ofthe MG, ^^^^. This means, the DSR is triggered exactly at the start of the MG with the proposed modification of the RT threshold.

[0095] Additionally or alternatively, it may be beneficial to add a (time) margin so that theDSR is not triggered at the exact point the MG starts. Instead, the DSR is triggered at least ^ms prior to ^^^^. In this case the abvove step S33 is modified as step S33a:- If ^^^^ − ^ − ^ ≤ ^^(^) − ^^^^^^^^^ ≤ ^^^^ − ^- ^^^(^) = ^^^^^^^^^ + [^^(^) − ^^^^^^^^^ − ( ^^^^ − ^)] + ^

[0096] Similarly, it may be beneficial to trigger the DSR transmission prior to the MG startseven if the UE estimates that the DSR would have been triggered within the first ^ ms after endof the MG (i.e., ^^^^), in which case the abvove step S33 is modified as Step S33b:- If ^^^^ − ^ − ^ ≤ ^^(^) − ^^^^^^^^^ ≤ ^^^^ + ^ − ^- ^^^(^) = ^^^^^^^^^ + [^^(^) − ^^^^^^^^^ − ( ^^^^ − ^)] + ^

[0097] Numerical examples for the above proposed method are given in the following.

[0098] As a first numerical example, assume that a PDCP PDU arrives in the UE buffer attime ^ − 9 ^^. The PDCP discard timer is set to 20 ms. At time ^ the remaining time is 11 ms.There is an MG with a duration of 6 ms that starts at ^^^^ = ^ + 8 ^^ and ends at ^^^^ =^ + 14 ^^. Further, the remaining time threshold is set to 5 ms, i.e., ^^^^^^^^^ = 5 ^^.

[0099] At time ^:^^(^) = 11 ^^,^^(^) − ^^^^^^^^^ = 11 ^^ − 5 ^^ = 6 ^^,^^^^ − ^ = 8 ^^, and^^^^ − ^ = 14 ^^.

[0100] In the above example, since 0 < ^^(^) − ^^^^^^^^^ < ^^^^ − ^ (i.e., 0 < 6 ms< 8 ms), ^^^(^) = ^^^^^^^^^ = 5 ^^ . In this case, according to Step S32 it is notnecessary to change ^^^(^).

[0101] As a second numerical example, assume that the MG with a duration of 6 ms startsat ^^^^ = ^ + 5 ^^ and ends at ^^^^ = ^ + 11 ^^. The remaining time threshold is still setto 5 ms.

[0102] At time ^:^(^) = 11 ^^^(^) − ^^^^^^^^^ = 11 ^^ − 5 ^^ = 6 ^^.^^^^ − ^ = 5 ^^.^^^^ − ^ = 11 ^^.

[0103] In the above example, since ^^^^ − ^ < ^(^) − ^^^^^^^^^ < ^^^^ − ^ (i.e., 5ms < 6 ms < 11 ms), then

[0104] In this case, according to Step S33, ^^^(^) changes and the DSR is triggered whenthe minimum remaining time becomes smaller than 6 ms, i.e., exactly at the start of the measurement gap.

[0105] Figure 4 schematically illustrates a method according to the sub-option 1a fordynamic change / adaptation / adjustment of the RT threshold being a function of time.

[0106] At step S40: the UE determines the ^^ at time ^^(^).

[0107] At step S41: the UE determines according to sub-option 1a if ^^^^ − ^ − ^ ≤^^(^) − ^^^^^^^^^ ≤ ^^^^ + ^ − ^ based on the above step S33b (or the UEdetermines the condition alternatively based on either of the above steps S33 and S33a).

[0108] At step S42: if the above condition in step S41 is determined to be true, the value ofthe remaining time threshold is adjusted based on any one of the above steps S33, S33a and S33b.

[0109] At step S43: Otherwise, if the above condition in step S41 is determined not to betrue, the value of the remaining time threshold is kept unchanged, i.e. equal to the value which is configured by RRC (i.e., remainingTimeThreshold).

[0110] At step S44, ^^(^) is compared against the value of the remaining time thresholddetermined at step S42 or step S43, to determine if a DSR is to be triggered at step S45.

[0111] Sub-option 1b): The purpose is to change RT when the UE estimates the DSR willbe triggered within the MG duration. In this sub-option, it is proposed to define a dynamic RTas a function of time ^ ^ ^^^(^).

[0112] An example is depicted in Figure 5 that schematically illustrates a timing diagramaccording to the sub-option 1b for dynamic change / adaptation / adjustment of the RT being afunction of time.

[0113] According to the present discloure, first the UE determines ^^ at time ^^^(^),and then performs the following steps:- Step S51: If ^^(^) − ^^^^^^^^^ ≤ ^- ^^^(^) = ^^(^)- Step S52: If ^ < ^^(^) − ^^^^^^^^^ < ^^^^ − ^- ^^^(^) = ^^(^)- Step S53: Else if ^^^^ − ^ ≤ ^^(^) − ^^^^^^^^^ ≤ ^^^^ − ^- ^^^(^) = ^^(^) − [^^(^) − ^^^^^^^^^ − ( ^^^^ − ^)]- Step S54: Else if ^^^^ − ^ < ^^(^) − ^^^^^^^^^- ^^^(^) = ^^(^)

[0114] Based on the above step S53, it is proposed in accordance with the present disclosurethat 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 whichcorresponds to the MG / SMTC.

[0115] According to the present disclosure, if the UE estimates that the DSR would havebeen triggered within the MG duration, ^^^(^) is decreased such that a DSR could be triggeredbeforehand. The remaining time is decreased by an amount [^^(^) − ^^^^^^^^^ −( ^^^^ − ^)] corresponding to the difference between the time when the DSR would havebeen triggered (i.e., the time marked with the vertical dashed line in Figure 5) and the start ofthe MG. This means, the DSR is triggered exactly at the start of the MG with the proposed modification of the RT.

[0116] Additionally or alternatively, it may be beneficial to add a (time) margin so that theDSR is not triggered at the exact point the MG starts. Instead, the DSR is triggered at least ^ms prior to ^^^^. In this case the above step S53 is modified as S53a:- If ^^^^ − ^ − ^ ≤ ^^(^) − ^^^^^^^^^ ≤ ^^^^ − ^- ^^^(^) = ^^(^) − [^^(^) − ^^^^^^^^^ − ( ^^^^ − ^)] − ^

[0117] Similarly, it may be beneficial to trigger the DSR transmission prior to the MG startseven if the UE estimates that the DSR would have been triggered within the first ^ ms after endof the MG (i.e., ^^^^), in which case the above step S53 is modified as S53b:- If ^^^^ − ^ − ^ ≤ ^^(^) − ^^^^^^^^^ ≤ ^^^^ + ^ − ^- ^^^(^) = ^^^^^^^^^ − [^^(^) − ^^^^^^^^^ − ( ^^^^ − ^)] −^

[0118] For sub-option 1b, the same first numerical example is used as for sub-option 1a,with the following assumptions:^ A PDCP PDU arrives in the UE buffer at time ^ − 9 ^^.^ The PDCP discard timer is 20 ms.^ At time ^ the remaining time is 11 ms.^ A MG, with a duration of 6 ms, starts at ^^^^ = ^ + 8 ^^ and ends at ^^^^ =^ + 14 ^^.^ The remaining time threshold is set to 5 ms, i.e., ^^^^^^^^^ = 5 ^^.

[0119] The above assumptions lead to the following results:^^(^) = 11 ^^,^^(^) − ^^^^^^^^^ = 11 ^^ − 5 ^^ = 6 ^^,^^^^ − ^ = 8 ^^, and^^^^ − ^ = 14 ^^.

[0120] In this example, since 0 < ^^(^) − ^^^^^^^^^ < ^^^^ − ^ (0 < 6 ms < 8 ms),^^^(^) = ^^ = 11 ^^. In this case, according to the above step S52, it is not necessary tochange ^^^(^).

[0121] Further, for sub-option 1b, the same second numerical example is also used as forsub-option 1a, wherein it is assumed that the MG with a duration of 6 ms starts at ^^^^ = ^ +5 ^^ and ends at ^^^^ = ^ + 11 ^^. The remaining time threshold is still set to 5 ms. Thisleads to the following results: ^(^) = 11 ^^^(^) − ^^^^^^^^^ = 11 ^^ − 5 ^^ = 6 ^^.^^^^ − ^ = 5 ^^.^^^^ − ^ = 11 ^^.

[0122] In this example, since ^^^^ − ^ < ^(^) − ^^^^^^^^^ < ^^^^ − ^ (5 ms < 6 ms< 11 ms), then

[0123] In this case, ^^^(^) changes / is adjusted and the DSR is triggered when the minimumremaining time becomes smaller than 5 ms, i.e., exactly at the start of the measurement gap.Second implementation option / alternative (Alt. 2)

[0124] For the second implementation option (Alt. 2), it is proposed in accordance withthe present disclosure to introduce a new DSR trigger prior to the start of a MG / SMTC withscheduling restrictions. According to the present disclosure, the trigger occurs so that the DSRcan be transmitted at the latest in the last UL slot available prior the MG / SMTC starts. The timebetween 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 (^^).

[0125] An example is depicted in Figure 6 that schematically illustrates a timing diagramaccording to the alternative Alt.2 for introducing a new DSR trigger based on a pre-configuredtime margin, e.g., a minimum re-tuning time. As shown in this Figure, it is proposed inaccordance with Alt.2 that at the determined time for triggering the DSR, the amount of timethat remains before the start of the time window is at least equal to ^^.

[0126] According to the present disclosure, there are proposed two sub-options forintroducing such a new DSR trigger e.g., in MAC specifications.

[0127] 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 beimplemented by using e.g., a DSR timer. -The DSR timer is first set (at time ^) to a value corresponding to ^^^^^,^ − ^^ − ^′,where ^^^^^,^ − ^^ is the time to the start of the next MG (MG #n) and ^′ is a networkconfigured parameter. The parameter ^^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 ^^on the UE capability. If ^^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^^^^^,^^^ − ^^ − ^′, where ^^^^^,^^^ − ^^ − ^′, is the time to the start of the MGfollowing the next MG (i.e., MG#n+1).

[0128] Implementation sub-option 2b): the existing DSR triggering based on remainingtime threshold is modified so that DSR is always triggered a certain amount of timeprior to a MG / SMTC with scheduling restrictions. In practice, this can be realized as a special case of the method according to sub-option 1a 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

[0129] More specifically, the method therefore proposed in accordance with sub-option 2bis illustrated in Figure 7, wherein the UE performs the following steps.

[0130] At step S70: the UE determines the ^^ at time ^ ^ ^^(^).

[0131] At step S71: the UE determines according to sub-option 2b if the time to the start ofthe next MG / SMTC with scheduling restrictions is smaller or equal than the predefined value^′, i.e. if (^^^^ − ^) ≤ ^′.

[0132] At step S72: if the above condition in step S71 is determined to be true, the value ofthe remaining time threshold is set to infinity.

[0133] At step S73: Otherwise, if the above condition in step S71 is determined not to betrue, the value of the remaining time threshold is kept unchanged, i.e. equal to the value which is configured by RRC (i.e., remainingTimeThreshold).

[0134] According to the present disclosure, the UE may use a timer-based approach as theone 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.

[0135] At step S74, ^^(^) is compared against the value of the remaining time thresholddetermined at step S72 or step S73, to determine if a DSR is to be triggered at step S75.

[0136] According to the present disclosure, after the UE performs adjustment of theminimum remaining time for the LCH or LCG and / or the remaining time threshold configuredfor triggering of the DSR, a comparison between the adjusted values of the minimum remainingtime for the LCH or LCG and the remaining time threshold configured for triggering of theDSR is performed.

[0137] Therein, the comparison of adjusted values may include e.g. perform a thirddetermining 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 the MG (i.e.,〖TMG〗_e). Network-side RRM method based on DSR

[0138] Upon reception of the DSR report sent by the UE, the network determines whetherthere 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.

[0139] Figure 8 illustrates the flowchart of the determination executed by the network.

[0140] At step S80, the network node recevices a DSR MAC CE from the UE.

[0141] At step S81, the network node determines whether there are enough radio resourcesto serve the UE buffered data within the remaining time before the next measurement gap.

[0142] At step S82, if the network node determines that there are enough radio resources toserve 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.

[0143] At step S83, the network node schedules radio resources according to the resourcesdetermined in step S81.

[0144] At step S84, the network node sends to the UE an indication to skip the nextmeasurement gap.

[0145] In one example, the determination S81 executed by the network is based on thefollowing 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 servedin 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.

[0146] Additionally, the determination S81 executed by the network consists of thefollowing steps: -The network evaluates a plurality of scheduling configurations, wherein eachconfiguration 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 communicatedin the last BSR report by the UE. -As last step, the network selects the configuration with the smallest expected deliverytime ^^^(^^), where ^^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 ^^= ^^^^ − ^^ (i.e., the network evaluates if ^^^^^^ ^ < ^^).- If the condition holds true, then there are enough radio resources to serve the UEbefore the next MG.

[0147] In summary, it is proposed in accordance with the present disclosure a specificsolution 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 pre- configured 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.

[0148] It is noted that, although in the above-illustrated example embodiments (withreference to the figures), the messages communicated / exchanged between the networkcomponents / elements may appear to have specific / explicit names, depending on variousimplementations (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.

[0149] According to some example embodiments, there are also provided correspondingmethods suitable to be carried out by the apparatuses (network elements / components) as described above, such as the UE, the CU, the DU, etc.

[0150] It should nevertheless be noted that the apparatus (device) features described abovecorrespond 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.

[0151] Further, according to some further example embodiments, there is also provided arespective apparatus (e.g., implementing the UE, the CU, the DU, etc., as described above) thatcomprises at least one processing circuitry, and at least one memory for storing instructions tobe 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 atleast perform the respective steps as described above.

[0152] 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.

[0153] It is to be noted that examples of embodiments of the disclosure are applicable tovarious 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.

[0154] It should also to be noted that the disclosed example embodiments can beimplemented 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 figuresare 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 twoor more such components implementing particular embodiments of the present disclosure.

[0155] It should further be noted that the description and drawings merely illustrate theprinciples 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 UL: Uplink XR: Extended Reality

Claims

CLAIMS:

1. 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:determine a start time and an end time of a first time window comprising at least asecond time window with uplink scheduling restrictions; andif, based on the determining, a time that remains before the start time of the first timewindow is equal to or smaller than a pre-configured time margin, perform triggering of aDelay Status Report, DSR.

2. The UE according to claim 1, wherein the first time window and the second time windowhave a same start time and a same end time, and / or the start time of the first time window isbefore a start time of the second time window, and / or the end time of the first time window isafter 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 set a valueof a DSR trigger timer to a difference between said time that remains before the start time ofthe first time window and the pre-configured time margin, wherein when the DSR trigger timerexpires, the UE is configured to trigger the DSR.

4. The UE according to claim 3, wherein after the DSR trigger timer associated with the first time window expires, the UE is further configured to set a value of the DSR trigger timerassociated with a next time window that follows the first time window to a difference betweena time that remains before a start time of the next time window and the pre-configured timemargin.

5. The UE according to any one of claims 1 to 4, wherein if determining that said time thatremains before the start time of the first time window is smaller than or equal to the pre-configured time margin, the UE is further configured to adjust a value of a remaining timethreshold configured for triggering the DSR to infinity.

6. The UE according to any one of claims 1 to 5, wherein if determining that said time thatremains before the start time of the first time window is greater than the pre-configured timemargin, the UE is configured to keep a value of a remaining time threshold configured fortriggering the DSR as a pre-configured value.

7. The UE according to any one of claims 1 to 6, wherein the UE is further configured to, basedon a comparison between values of a minimum remaining time for a Logical Channel, LCH, ora Logical Channel Group, LCG and a remaining time threshold configured for triggering theDSR, perform triggering of the DSR.

8. The UE according to any one of claims 1 to 7, wherein the pre-configured time margin isequal to or greater than a time difference between the start time of the first time window and the last available uplink slot before the start time of the first time window.

9. The UE according to any one of claims 1 to 8, wherein the UE is further configured to determine the pre-configured time margin based on UE capability for skipping the uplink scheduling restrictions.

10. The UE according to any one of claims 1 to 9, wherein the pre-configured time margin comprises a period of time for the DSR to be transmitted to a network node and a period of timefor the network node to, in response to the received DSR, send to the UE an indication forskipping the uplink scheduling restrictions.

11. The UE according to any one of claims 1 to 10, wherein the pre-configured time margin comprises a Radio Frequency, RF, re-tuning time.

12. The UE according to any one of claims 1 to 11, wherein a remaining time thresholdconfigured for triggering the DSR is a threshold on a minimum remaining time for a LogicalChannel, LCH, or a Logical Channel Group, LCG, wherein a value of the remaining timethreshold configured for triggering the DSR corresponds to a pre-configured period of timeuntil expiration of a Packet Data Convergence Protocol, PDCP, discard timer corresponding toa Service Data Unit, SDU, associated with uplink data for which the DSR is to be triggered.

13. The UE according to any one of claims 1 to 12, wherein a minimum remaining time for aLogical Channel, LCH, or a Logical Channel Group, LCG refers to the smallest value ofremaining times of running Packet Data Convergence Protocol, PDCP, discard Timers amongall Service Data Units, SDUs that are buffered for the LCG or LCH and that have not beentransmitted in any Medium Access Control, MAC, Protocol Data Unit, PDU and that have notbeen reported as data volume in a DSR MAC control element, CE.

14. The UE according to any one of claims 1 to 13, wherein the second time window isassociated with an SSB Measurement Time Configuration, SMTC, or a Measurement Gap, MG, for the RRM measurements.

15. A network node of a radio access network, configured to establish a communication to aUser Equipment, UE, the network node comprising: 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: transmit to the UE configuration information comprising a pre-configured time margin for the UE to perform triggering of a Delay Status Report, DSR, earlier than or at a starttime of a first time window comprising at least a second time window with uplinkscheduling restrictions.

16. The network node according to claim 15, wherein the network node is further configured toreceive from the UE the DSR and if, based on the received DSR, the network node determinesthat there are insufficient radio resources for serving uplink data buffered at UE within a periodof time that remains before the start time of the first time window, the network node is furtherconfigured to instruct the UE to skip the uplink scheduling restrictions.

17. The network node according to claim 16, wherein the network node is further configuredto, for determining whether there are sufficient radio resources:at a time at which the determination in relation to radio resources is executed, selectfor the UE a corresponding scheduling configuration with the smallest expecteddelivery time, andevaluate a condition of whether the smallest expected delivery time is smaller than theperiod of time that remains before the start time of the first time window;wherein if the network determines that the condition holds true: determine that thereare sufficient radio resources for serving the UE within the period of time that remainsbefore the start time of the first time window.

18. A method of a User Equipment, UE, the method comprising:determining a start time and an end time of a first time window comprising at least asecond time window with uplink scheduling restrictions; andif, based on the determining, a time that remains before the start time of the first timewindow is equal to or smaller than a pre-configured time margin, performing triggeringof a Delay Status Report, DSR.

19. A method of a network node of a radio access network, configured to establish acommunication to a User Equipment, UE, the method comprising:transmitting to the UE configuration information comprising a pre-configured time margin for the UE to perform triggering of a Delay Status Report, DSR, earlier than orat a start time of a first time window comprising at least a second time window withuplink scheduling restrictions.

20. A computer program comprising instructions for causing an apparatus to perform the method according to claim 18 or claim 19.

21. A memory storing computer readable instructions for causing an apparatus to perform the method according to claim 18 or claim 19.

22. A first network node that supports at least one of central unit control plane, CU-CP,functionality or a layer 3 protocol of a radio access network, comprising: at least one processor; and at least one memory storing instruction which, when executed by the at least one processor, cause the first network node at least to: establish a connection with a user equipment apparatus, UE, via a serving cell; andtransmit to the UE configuration information comprising a pre-configured time margin for the UE to perform triggering of a Delay Status Report, DSR, earlier than or at a starttime of a first time window comprising at least a second time window with uplinkscheduling restrictions.

23. A second network node that supports at least one of the distributed unit, DU, functionality or a layer 2 protocol of a radio access network, and which supports a first cell, further comprising: at least one processor; and at least one memory storing instruction which, when executed by the at least one processor, cause the second network node at least to: establish a connection with a user equipment apparatus, UE, via the first cell acting asa serving cell; and transmit to the UE configuration information comprising a pre-configured time margin for the UE to perform triggering of a Delay Status Report, DSR, earlierthan or at a start time of a first time window comprising at least a second timewindow with uplink scheduling restrictions.

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