Network- or UE-controlled resumption of radio resource management measurements in measurement windows

Abstract

Techniques are provided, which enable network-controlled or User Equipment (UE)- controlled resumption of Radio Resource Measurement (RRM) measurements in a next measurement window (e.g., a Measurement Gap (MG) or Synchronization Signal (SS) / Physical Broadcast Channel (PBCH) Block Measurement Timing Configuration (SMTC) window) after receiving a skipping command. According to the techniques, either a UE or a network node is configured to evaluate whether at least one condition for resuming the RRM measurements in the next measurement window is satisfied during a pre-defined evaluation timer. If this is the case, the UE may decide itself or be instructed by the network node to ignore the skipping command and resume the RRM measurements in the next measurement window.

Description

[0001] NETWORK- OR UE-CONTROLLED RESUMPTION OF RADIO RESOURCE MANAGEMENT MEASUREMENTS IN MEASUREMENT WINDOWS

[0002] TECHNICAL FIELD

[0003] The present disclosure relates generally to the field of wireless communications. In particular, the present disclosure relates to techniques for network-controlled or User Equipment (UE)-controlled resumption of Radio Resource Measurement (RRM) measurements in a next measurement window after receiving a skipping command.

[0004] BACKGROUND

[0005] In line with the Rel-17 extended Reality (XR) simulation assumptions (see 3GPP TR 38.838) for Frequency Range 2 (FR2), UEs are equipped with multiple antenna panels, and the UEs may only be able to measure and perform transmission / reception (Tx / Rx) on a single antenna panel at a time. A UE may select its best antenna panel for Tx / Rx with its serving cell based on local RRM measurements (e.g., Reference Signal Received Power (RSRP) measurements). The UE may also perform intra-frequency RRM measurements for mobility and beam management purposes. However, in some cases, there are additional scheduling restrictions due to, e.g., the intra-frequency or inter-frequency RRM measurements that challenge XR performance. Some examples of such scheduling restrictions are given in 3GPP TR 38.133.

[0006] As follows from the current New Radio (NR) specifications, a network node (e.g., gNB) configures the UE's schedule of when the UE is to measure an RSRP from, e.g., Synchronization Signal (SS) Blocks (SSBs) by means of Radio Resource Control (RRC) signaling of the so-called SS / Physical Broadcast Channel (PBCH) Block Measurement Timing Configuration (SMTC) (see section 5.5.2.10 in 3GPP TR 38.331). The time resolution of an SMTC window is on subframe level, corresponding to 1-ms intervals. It should be noted that the SMTC only instructs the UE when (in the time domain) it can / should measure, e.g., the RSRP from the SSB, while it is left completely open for the UE implementation when exactly it will perform the RRM measurements and which antenna panel will be used to perform such RRM measurements during SMTC windows.

[0007] Scheduling restrictions apply to UEs during time slots when they can perform SSB-based measurements in accordance with the SMTC configuration presented in3GPP TR 38.133 (see Section 9.5.6.3). Some network configurations may use a setting with SMTC windows of 5 ms every 20 ms (aligned to a SSB periodicity), meaning that this poses serious scheduling restrictions that likely challenge the gNB's capability to efficiently schedule and serve its XR users according to their Quality-of-Service (QoS) constraint, severely limiting the XR capacity if such scheduling restrictions are valid. The consideration that the scheduling restrictions will apply to SSBs to be measured, starting one symbol before and ending one symbol after, means that in practice each slot where SSBs are to be measured is limited in terms of a Physical Downlink Shared Channel (PDSCH), resulting in almost 25% of the time (i.e., the SMTC windows of 5 ms every 20 ms) being blocked if 64 SSBs are to be measured. In addition, the current NR specifications are silent on how / when a UE should / can take measurements on different antenna panels, and / or when it should only take measurements on its currently selected best antenna panel (aligned with a serving cell).

[0008] Currently, there are solutions that allow UEs to skip the RRM measurements in a certain MG or SMTC window shortly before it starts (to avoid the scheduling restrictions). Such solutions can be grouped into network-centric solutions and UE-centric solutions. In the networkcentric solutions, the gNB signals a skipping command to the UE, which indicates when the UE should prioritize Rx / Tx over the RRM measurements in a next MG or SMTC window (i.e., skip the RRM measurements). In the UE-centric solutions, a set of conditions configured by the gNB allows the UE to make an autonomous decision on whether to prioritize Rx / Tx over the RRM measurements or vice versa. However, in all these solutions, the impact of UE mobility is not explicitly discussed when a radio environment is more dynamic. More specifically, for the network-centric solutions, the skipping command may already be outdated when the UE is moving towards a cell edge and an event-based handover (HO) procedure is initiated. SUMMARY

[0009] This summary is provided to introduce a selection of concepts in a simplified form that are further described below in the detailed description. This summary is not intended to identify key features of the present disclosure, nor is it intended to be used to limit the scope of the present disclosure.

[0010] It is an objective of the present disclosure to provide a technical solution that allows a UE to resume a RRM measurement in next measurement windows (e.g., MGs or SMTC windows) based on its mobility status after receiving a skipping command from a network node.

[0011] The objective above is achieved by the features of the independent claims in the appended claims. Further embodiments and examples are apparent from the dependent claims, the detailed description, and the accompanying drawings.

[0012] According to a first aspect, a UE in a wireless communication network is provided. The UE comprises at least one processor and at least one memory storing instructions that, when executed by the at least one processor, cause the UE to operate at least as follows. At first, the UE receives configuration information from a network node in the wireless communication network. The configuration information comprises an instruction for the UE to continuously transmit at least one of a RRM measurement and a mobility state parameter to the network node during an evaluation timer before a next measurement window (e.g., MG or SMTC window). Then, the UE receives a skipping command from the network node, which instructs the UE to skip the RRM measurement in the next measurement window. Next, the UE triggers the evaluation timer and continuously transmits said at least one of the RRM measurement and the mobility state parameter to the network node until the evaluation timer expires. After that, the UE receives a first message or a second message from the network node. The first message indicates the UE is allowed to ignore the skipping command and resume the RRM measurement in the next measurement window. The second message indicates that the UE needs to execute the skipping command, i.e., skip the RRM measurement in the next measurement window. The UE thus configured may verify (with the aid of the network node) whether the skipping command for the next measurement window (e.g., MG / SMTC window) is still valid based on its mobility status (which is implied due to the evaluation of the condition(s) during the duration of the evaluation timer). The resumption of the RRM measurement in the next measurement window instantiates again the legacy UE approach of prioritizing RRM measurements over Physical Downlink Control Channel (PDCCH) / PDSCH decoding or Physical Uplink Control Channel (PUCCH) / Physical Uplink Shared Channel (PUSCH) transmission.

[0013] In one example embodiment of the first aspect, the UE is further caused, in response to the skipping command, to perform the RRM measurement before the next measurement window and determine whether the RRM measurement is less than a threshold value. If the RRM measurement is less than the threshold value, the UE is caused to trigger the evaluation timer. Thus, the UE may not trigger the evaluation timer automatically in response to receiving the skipping command, but only after checking the additional condition that the RRM measurement is below a certain threshold value. By doing so, the UE may trigger the evaluation timer at the most appropriate times, thus reducing energy and computational costs.

[0014] In one example embodiment of the first aspect, the mobility state parameter of the UE comprises at least one of: (i) a maximum number of handover failures, (ii) a maximum number of radio link failures, (iii) a maximum outage time; (iv) a speed variation range, (v) a maximum number of beam switches between the UE and the network node, (vi) a maximum value of a Beam Failure Indication (BFI) counter, and (vii) a maximum value of a UE panel switch counter. These mobility state parameters may facilitate more efficient verification of the validity of the current skipping command.

[0015] In one example embodiment of the first aspect, the UE is further caused, before receiving the configuration information, to transmit a request for the configuration information to the network node. Thus, the UE may request the RRM resumption-related configuration information on its own, or the network node (e.g., gNB) may directly send the configuration on top of the legacy RRM and scheduling restrictions signaling procedures. All of this may make the UE according to the first aspect more flexible in use.

[0016] According to a second aspect, a network node in a wireless communication network is provided. 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 to operate at least as follows. At first, the network node transmits configuration information to a UE in the wireless communication network. The configuration information comprises an instruction for the UE to continuously transmit at least one of a RRM measurement and a mobility state parameter to the network node during an evaluation timer before a next measurement window (e.g., MG or SMTC window). Then, the network node transmits a skipping command to the UE, which instructs the UE to skip the RRM measurement in the next measurement window. Next, the network node continuously receives, from the UE, said at least one of the RRM measurement and the mobility state parameter during the evaluation timer. By using said at least one of the RRM measurement and the mobility state parameter, the network node determines whether at least one condition for resuming the RRM measurement in the next measurement window has been satisfied during the evaluation timer. Further, the network node transmits, to the UE, a first message if the at least one condition for resuming the RRM measurement in the next measurement window has been satisfied during the evaluation timer or a second message if the at least one condition for resuming the RRM measurement in the next measurement window has not been satisfied during the evaluation timer. The first message indicates that the UE is allowed to ignore the skipping command and resume the RRM measurement in the next measurement window. The second message indicates that UE needs to execute the skipping command (i.e., skip the RRM measurement) in the next measurement window. The network node thus configured may provide network-controlled verification of whether the skipping command for the next measurement window (e.g., MG / SMTC window) is still valid based on the UE mobility status. The resumption of the RRM measurement in the next measurement window instantiates again the legacy UE approach of prioritizing RRM measurements over PDCCH / PDSCH decoding or PUCCH / PUSCH transmission.

[0017] In one example embodiment of the second aspect, the list of conditions comprises at least one of: (i) the RRM measurement is lower than a threshold value upon expiration of the evaluation timer, (ii) no RRM measurement is possible to perform for a maximum allowable period of time, and (iii) a mobility state parameter of the UE changes by a threshold value during the evaluation timer. By using these conditions, it is possible to verify the validity of the current skipping command more efficiently.

[0018] In one example embodiment of the second aspect, the mobility state parameter of the UE comprises at least one of: (i) a maximum number of handover failures, (ii) a maximum number of radio link failures, (iii) a maximum outage time, (iv) a speed variation range, (v) a maximum number of beam switches between the UE and the network node, (vi) a maximum value of a BFI counter, and (vii) a maximum value of a UE panel switch counter. These mobility state parameters may additionally facilitate more efficient verification of the validity of the current skipping command.

[0019] In one example embodiment of the second aspect, the network node is caused to transmit each of the first message and the second message via an independent LI or L2 signaling channel. By using the L1 / L2 signaling channel, the network node may provide the first and second messages to the UE more efficiently.

[0020] In one example embodiment of the second aspect, the network node is further caused receive a request for the configuration information from the UE and, in response, transmit the configuration information to the UE. Thus, the UE may request the RRM resumption- related configuration information on its own, or the network node (e.g., gNB) may directly send the configuration on top of the legacy RRM and scheduling restrictions signaling procedures. All of this may make the network node according to the second aspect more flexible in use.

[0021] According to a third aspect, a method for operating a UE in a wireless communication network is provided. The method starts with the step of receiving configuration information from a network node in the wireless communication network. The configuration information comprises an instruction for the UE to continuously transmit at least one of a RRM measurement and a mobility state parameter to the network node during an evaluation timer before a next measurement window (e.g., MG or SMTC window). Then, the method proceeds to the step of receiving a skipping command from the network node, which instructs the UE to skip the RRM measurement in the next measurement window. Next, the method goes on to the steps of triggering the evaluation timer and continuously transmitting said at least one of the RRM measurement and the mobility state parameter to the network node until the evaluation timer expires. Further, the method proceeds to the step of receiving, from the network node, one of: (i) a first message indicating that the UE is allowed to ignore the skipping command and resume the RRM measurement in the next measurement window, and (ii) a second message indicating that the UE needs to execute the skipping command (i.e., skip the RRM measurement) in the next measurement window. By doing so, the UE may verify (with the aid of the network node) whether the skipping command for the next measurement window (e.g., MG / SMTC window) is still valid based on its mobility status (which is implied due to the evaluation of the condition(s) during the duration of the evaluation timer). The resumption of the RRM measurement in the next measurement window instantiates again the legacy UE approach of prioritizing RRM measurements over PDCCH / PDSCH decoding or PUCCH / PUSCH transmission.

[0022] According to a fourth aspect, a method for operating a network node in a wireless communication network is provided. The method starts with the step of transmitting configuration information to a UE in the wireless communication network. The configuration information comprises an instruction for the UE to continuously transmit at least one of a RRM measurement and a mobility state parameter to the network node during an evaluation timer before a next measurement window (e.g., MG or SMTC window). Then, the method proceeds to the step of transmitting a skipping command to the UE, which instructs the UE to skip the RRM measurement in the next measurement window. Next, the method goes on to the step of continuously receiving, from the UE, said at least one of the RRM measurement and the mobility state parameter during the evaluation timer. Further, the method goes on to the step of using said at least one of the RRM measurement and the mobility state parameter to determine whether at least one condition for resuming the RRM measurement in the next measurement window has been satisfied during the evaluation timer. Subsequently, the method proceeds to the step of transmitting, to the UE, a first message if the at least one condition for resuming the RRM measurement in the next measurement window has been satisfied during the evaluation timer or a second message if the at least one condition for resuming the RRM measurement in the next measurement window has not been satisfied during the evaluation timer. The first message indicates that the UE is allowed to ignore the skipping command and resume the RRM measurement in the next measurement window. The second message indicates that UE needs to execute the skipping command (i.e., skip the RRM measurement) in the next measurement window. By doing so, the network node may provide network-controlled verification of whether the skipping command for the next measurement window (e.g., MG / SMTC window) is still valid based on the UE mobility status. The resumption of the RRM measurement in the next measurement window instantiates again the legacy UE approach of prioritizing RRM measurements over PDCCH / PDSCH decoding or PUCCH / PUSCH transmission.

[0023] According to a fifth aspect, a computer program product is provided. The computer program product comprises a computer-readable storage medium that stores a computer code. Being executed by at least one processor, the computer code causes the at least one processor to perform the method according to the third aspect. By using such a computer program product, it is possible to simplify the implementation of the method according to the third aspect in any UE, like the UE to the first aspect.

[0024] According to a sixth aspect, a computer program product is provided. The computer program product comprises a computer-readable storage medium that stores a computer code. Being executed by at least one processor, the computer code causes the at least one processor to perform the method according to the fourth aspect. By using such a computer program product, it is possible to simplify the implementation of the method according to the fourth aspect in any network node, like the network node to the second aspect.

[0025] According to a seventh aspect, a UE in a wireless communication network is provided. The UE comprises a means for receiving configuration information from a network node in the wireless communication network. The configuration information comprises an instruction for the UE to continuously transmit at least one of a RRM measurement and a mobility state parameter to the network node during an evaluation timer before a next measurement window (e.g., MG or SMTC window). The UE further comprises a means for receiving a skipping command from the network node, which instructs the UE to skip the RRM measurement in the next measurement window. The UE further comprises a means for triggering the evaluation timer and a means for continuously transmitting said at least one of the RRM measurement and the mobility state parameter to the network node until the evaluation timer expires. The UE further comprises a means for receiving a first message or a second message from the network node. The first message indicates the UE is allowed to ignore the skipping command and resume the RRM measurement in the next measurement window. The second message indicates that the UE needs to execute the skipping command, i.e., skip the RRM measurement in the next measurement window. The UE thus configured may verify (with the aid of the network node) whether the skipping command for the next measurement window (e.g., MG / SMTC window) is still valid based on its mobility status (which is implied due to the evaluation of the condition(s) during the duration of the evaluation timer). The resumption of the RRM measurement in the next measurement window instantiates again the legacy UE approach of prioritizing RRM measurements over PDCCH / PDSCH decoding or PUCCH / PUSCH transmission.

[0026] According to an eighth aspect, a network node in a wireless communication network is provided. The network node comprises a means for transmitting configuration information to a UE in the wireless communication network. The configuration information comprises an instruction for the UE to continuously transmit at least one of a RRM measurement and a mobility state parameter to the network node during an evaluation timer before a next measurement window (e.g., MG or SMTC window). The network node further comprises a means for transmitting a skipping command to the UE, which instructs the UE to skip the RRM measurement in the next measurement window. The network node further comprises a means for continuously receiving, from the UE, said at least one of the RRM measurement and the mobility state parameter during the evaluation timer. The network node further comprises a means for using said at least one of the RRM measurement and the mobility state parameter to determine whether at least one condition for resuming the RRM measurement in the next measurement window has been satisfied during the evaluation timer. The network node further comprises a means for transmitting, to the UE, a first message if the at least one condition for resuming the RRM measurement in the next measurement window has been satisfied during the evaluation timer or a second message if the at least one condition for resuming the RRM measurement in the next measurement window has not been satisfied during the evaluation timer. The first message indicates that the UE is allowed to ignore the skipping command and resume the RRM measurement in the next measurement window. The second message indicates that UE needs to execute the skipping command (i.e., skip the RRM measurement) in the next measurement window. The network node thus configured may provide network-controlled verification of whether the skipping command for the next measurement window (e.g., MG / SMTC window) is still valid based on the UE mobility status. The resumption of the RRM measurement in the next measurement window instantiates again the legacy UE approach of prioritizing RRM measurements over PDCCH / PDSCH decoding or PUCCH / PUSCH transmission. Other features and advantages of the present disclosure will be apparent upon reading the following detailed description and reviewing the accompanying drawings.

[0027] BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The present disclosure is explained below with reference to the accompanying drawings in which:

[0029] FIG. 1 shows a schematic structure of an SMTC window with scheduling restrictions, and the arrival of XR frames;

[0030] FIG. 2 shows a block diagram of a UE in a wireless communication network in accordance with one example embodiment;

[0031] FIG. 3 shows a block diagram of a network node in the wireless communication network in accordance with one example embodiment;

[0032] FIG. 4 shows a signaling procedure for performing a network-controlled resumption of RRM measurements in a next measurement window in accordance with a first example embodiment;

[0033] FIG. 5 schematically illustrates how an evaluation timer used in the signaling procedure of FIG. 4 may be used to evaluate conditions for resuming RRM measurements in the next measurement window;

[0034] FIG. 6 shows a signaling procedure for performing the network-controlled resumption of RRM measurements in the next measurement window in accordance with a second example embodiment;

[0035] FIG. 7 shows a signaling procedure for performing a UE-controlled resumption of RRM measurements in a next measurement window in accordance with a first example embodiment; and

[0036] FIG. 8 shows a signaling procedure for performing the UE-controlled resumption of RRM measurements in the next measurement window in accordance with a second example embodiment. DETAILED DESCRIPTION

[0037] Various embodiments of the present disclosure are further described in more detail with reference to the accompanying drawings. However, the present disclosure can be embodied in many other forms and should not be construed as limited to any certain structure or function discussed in the following description. In contrast, these embodiments are provided to make the description of the present disclosure detailed and complete.

[0038] According to the detailed description, it will be apparent to the ones skilled in the art that the scope of the present disclosure encompasses any embodiment thereof, which is disclosed herein, irrespective of whether this embodiment is implemented independently or in concert with any other embodiment of the present disclosure. For example, the apparatuses and methods disclosed herein can be implemented in practice by using any numbers of the embodiments provided herein. Furthermore, it should be understood that any embodiment of the present disclosure can be implemented using one or more of the elements presented in the appended claims.

[0039] Unless otherwise stated, any embodiment recited herein as "example embodiment" should not be construed as preferable or having an advantage over other embodiments.

[0040] According to the example embodiments disclosed herein, a User Equipment (UE) may refer to an electronic computing device that is configured to perform wireless communications. The UE may be implemented as a mobile station, a mobile terminal, a mobile subscriber unit, a mobile phone, a cellular phone, a smart phone, a cordless phone, a personal digital assistant (PDA), a wireless communication device, a laptop computer, a tablet computer, a gaming device, a netbook, a smartbook, an ultrabook, a medical mobile device or equipment, a biometric sensor, a wearable device (e.g., a smart watch, smart glasses, a smart wrist band, etc.), an entertainment device (e.g., an audio player, a video player, etc.), a vehicular component or sensor (e.g., a driver-assistance system), a smart meter / sensor, an unmanned vehicle (e.g., an industrial robot, a quadcopter, etc.) and its component (e.g., a self-driving car computer), industrial manufacturing equipment, a global positioning system (GPS) device, an Internet-of-Things (loT) device, an Industrial loT (HoT) device, a machine-type communication (MTC) device, a group of Massive loT (MIoT) or Massive MTC (mMTC) devices / sensors, or any other suitable mobile device configured to support wireless communications. In some embodiments, the UE may refer to at least two collocated and inter-connected UEs thus defined.

[0041] As used in the example embodiments disclosed herein, a network node may refer to a fixed point of communication / communication node for a UE in a particular wireless communication network. More specifically, the network node may be used to connect the UE to a Data Network (DN) through a Core Network (CN) and may be referred to as a base transceiver station (BTS) in terms of the 2G communication technology, a NodeB in terms of the 3G communication technology, an evolved NodeB (eNodeB) in terms of the 4G communication technology, and a gNB in terms of the 5G New Radio (NR) communication technology. The network node may serve different cells, such as a macrocell, a microcell, a picocell, a femtocell, and / or other types of cells. The macrocell may cover a relatively large geographic area (for example, at least several kilometers in radius). The microcell may cover a geographic area less than two kilometers in radius, for example. The picocell may cover a relatively small geographic area, such, for example, as offices, shopping malls, train stations, stock exchanges, etc. The femtocell may cover an even smaller geographic area (for example, a home).

[0042] According to the example embodiments disclosed herein, a wireless communication network, in which a UE and a network node communicate with each other, may refer to a cellular or mobile network, a Wireless Local Area Network (WLAN), a Wireless Personal Area Networks (WPAN), a Wireless Wide Area Network (WWAN), a satellite communication (SATCOM) system, or any other type of wireless communication networks. Each of these types of wireless communication networks supports wireless communications according to one or more communication protocol standards. For example, the cellular network may operate according to the Global System for Mobile Communications (GSM) standard, the Code-Division Multiple Access (CDMA) standard, the Wide-Band Code-Division Multiple Access (WCDM) standard, the Time-Division Multiple Access (TDMA) standard, or any other communication protocol standard, the WLAN may operate according to one or more versions of the IEEE 802.11 standards, the WPAN may operate according to the Infrared Data Association (IrDA), Wireless USB, Bluetooth, or ZigBee standard, and the WWAN may operate according to the Worldwide Interoperability for Microwave Access (WiMAX) standard.

[0043] FIG. 1 shows a schematic structure of an SMTC window with scheduling restrictions, and the arrival of XR frames. The SMTC window is configured by a gNB for a UE. As can be seen, the timing of each SMTC window (schematically shown as a solid box) is assumed to be 5 ms, and the SMTC-induced scheduling restrictions are assumed to come every 20 ms. In the meantime, the average inter-arrival time of the XR frames (schematically shown as vertical bars) is 16.6 ms (assuming 60 fps). On top of that, each XR frame arrival is subject to + / -4ms jitter, as illustrated with dashed arrows. As follows from FIG. 1, the SMTC windows with the scheduling restrictions often collide with the time periods where a gNB would prefer to schedule XR transmissions. This will impact the XR Quality of Experience (QoE) and will negatively impact the obtained network XR capacity.

[0044] The system-level performance degradation from the above-mentioned scheduling restrictions in FR2 have been evaluated in several contributions to both RANI and RAN, showing a capacity loss ranging from about 5% to more than 50%, depending on the assumed Packet Delay Budget (PDB) and SMTC configuration. The performance degradation is summarized in Table 1 below (where "CG" refers to " Cloud gaming", "AR" and "VR" stand for "Augmented Reality" and "Virtual Reality", respectively). More specifically, Table 1 shows the percentage of satisfied XR users obtained from system-level simulations for a Distributed Unit (DU) at FR2 with 30 Mbps and 99% of XR frames received within PDBs of 10ms and 15 ms, with / without scheduling restrictions during SMTC periods. As can be seen, the relaxation of the scheduling restrictions based on the network configuration is needed to improve the XR capacity, at least in medium to low mobility scenarios.

[0045] Table 1: Number of satisfied XR users per cell for different SMTC configurations in FR2, DU, 30 Mbps

[0046] In any telecom technology (like 2G, 3G, 4G or 5G), a mobility (handover) decision whether / when a mobile UE (e.g., a mobile phone) will perform handover (HO) is made by a network node (e.g., gNB) based on measurement reports from the mobile UE. There are multiple measurement items (e.g., Channel State Indicator (CSI), Channel Quality Indicator (CQI), Reference Signal Received Power (RSRP), Reference Signal Received Quality (RSRQ), Carrier Received Signal Strength Indicator (RSSI), Signal-to-Noise-and-lnterference Ratio (SINR), etc.) and multiple ways (e.g., periodic, event-triggered, etc.) to measure the signal quality of a serving cell and neighbor cells.

[0047] In an ideal case, a network node should allow a mobile UE to report the serving cell's and neighbor cell's signal qualities and trigger a HO with a single measurement, but in practice that can create overload conditions due to unnecessary Ping-Pong (PP) HOs. To avoid such situations, the 3GPP specifications include a predefined set of measurement report mechanisms to be performed by the UE. This predefined measurement report type is called "Event". The type of "Event" the UE must report is specified by an RRC signaling message sent by the network node. More specifically, the following events are currently defined for 5G NR (see 3GPP TR 38.331):

[0048] Event Al (A serving cell becomes better than a threshold);

[0049] Event A2 (A serving cell becomes worse than a threshold);

[0050] Event A3 (A neighbor becomes offset better than a Special Cell (SpCell ));

[0051] Event A4 (A neighbor becomes better than a threshold);

[0052] Event A5 (A SpCell becomes worse than thresholdl and a neighbor becomes better than threshold2);

[0053] Event A6 (A neighbour becomes offset better than a Secondary Cell (SCell ));

[0054] Event Bl (An Inter RAT neighbour becomes better than a threshold);

[0055] Event B2 (A Primary Cell (PCell) becomes worse than thresholdl and an inter RAT neighbor becomes better than threshold2). Event A2 is typically used to trigger a mobility procedure when a UE moves towards a cell edge. Event A2 does not involve any neighbor cell measurements, so it may be used to trigger a blind mobility procedure or it may be used to trigger neighbor cell measurements which can then be used for a measurement-based mobility procedure.

[0056] For example, a gNB may configure measurement gaps (MGs) and inter-frequency or intersystem RRM measurements after Event A2 has been triggered. This approach means that a UE only needs to complete the intra / inter frequency or inter-system RRM measurements where coverage conditions are relatively poor and there is a higher chance that a HO will be required.

[0057] A Baseline HO (BHO) BHO procedure employed to hand over data in the Long Term Evolution (LTE) standard is re-used in 5G networks as per 3GPP release 15. It consists of the following phases:

[0058] Trigger Phase: It defines configurations for neighboring frequencies as measurement (meas) objects, event report thresholds, and neighbor relation at a serving gNB's Operations, Administration and Maintenance (0AM) or Element Management System (EMS) entity, such that without these configurations the BHO will not trigger.

[0059] Measurement Phase: It includes delivery of meas objects and report configurations to a UE from the serving gNB as part of RRC Configuration. The UE then applies it successfully, where based on the configuration the UE does measure a neighbor and report a measurement report to the serving gNB, which includes the potential target cell PCI and signal strength.

[0060] Target Cell Decision Phase: After receiving the measurement report, the serving gNB must decide a target cell. The gNB selection for the target cell involves the following: o Processing the measurement report (Not required for a Blind HO); o Determining a HO Policy (i.e., HO or redirection); o Identifying the target cell or a target frequency.

[0061] Handover Phase: Once the target cell or the target frequency is identified, the HO procedure kicks off. Based on the network capability, the serving gNB can perform Xn based or N2 based HO, or can perform the redirection. Ll / L2-Triggered Mobility (LTM) is one of the objectives for upcoming mobility enhancement in release 18 and highly recommended for release 19. In contrast to L3 based-mobility procedures where the HO between two cells is decided by an RRC layer and terminated at a Control Unit (CU), the LTM is performed by a Media Access Control (MAC) layer terminated in a Distributed Unit (DU). The main phases of the LTM are summarized in the following:

[0062] In a preparation phase, a serving gNB decides to configure potential target cells for the LTM based on a measurement report received from a UE. The configuration for the LTM is sent to the UE.

[0063] After confirming RRC Reconfiguration to the serving gNB, the UE starts to report periodically LI beam measurements of serving and candidate target cells.

[0064] Upon determining that there is a target candidate cell having a better radio link beam measurement than the serving cell, e.g., the Ll-RSRP of a target beam measurement > the Ll-RSRP of a serving beam measurement + Off for, e.g., Time -to-Trigger (TTT) time, the serving gNB sends a MAC Control Element (MAC CE) or a LI message to trigger the cell change to the target candidate cell.

[0065] The HO from the serving cell to the target cell is executed by the UE.

[0066] The main benefit of the LTM compared to the BHO and a conditional HO is that the interruption during the HO execution can be reduced substantially as the UE does not need to perform higher layer (RRC, Packet Data Convergence Protocol (PDCP)) reconfiguration and for some scenarios UE can perform contention free Random Access (RACH) / RACHIess when connecting to the target cell.

[0067] It should be noted that skipping the RRM measurements and the scheduling restrictions in a next MG or SMTC window in the context of UE mobility in 5G networks can lead to a number of problems, especially when the UE rate is high or signal quality is low (e.g., in a cell edge scenario). The non-exhaustive list of problems is given below:

[0068] Problem 1 (HOF): Skipping the RRM measurements in the next MG / SMTC window or not adhering to the prescribed timing configurations can disrupt a HO process. In a mobile environment, UEs need time to perform necessary measurements to evaluate neighboring cells before executing a HO. If these measurements are skipped or not done correctly, it might result in incomplete or inaccurate information, leading to HO Failures (HOFs) or degraded quality during HOs.

[0069] Problem 2 (Unnecessary HOs / PPs): Skipping the RRM measurements or inaccurate HO decisions can trigger frequent and unnecessary HOs between cells, or PP.

[0070] Problem 3 (Suboptimal HO cell selection): Inaccurate RRM measurements or skipping the RRM measurements in the next MG / SMTC window can lead to suboptimal HO decisions. UEs might not choose the best-suited cell for a HO, resulting in degraded performance, dropped calls, or reduced user happiness.

[0071] Problem 4 (Extended interruption): If the RRM measurements are skipped or not performed accurately, a UE might need additional time to evaluate the quality of neighboring cells before making a HO decision. This delay can extend the interruption time, causing a longer period of connection loss for users during the HO process.

[0072] The example embodiments disclosed herein provide a technical solution that allows mitigating or eliminating the above-mentioned problems which may occur due to skipping the RRM measurements a next measurement window (e.g., MG / SMTC window). More specifically, the technical solution disclosed herein allows a UE to resume the RRM measurements in the next measurement window based on its mobility status after receiving a skipping command from a network node. For this purpose, either the UE or the network node is configured to evaluate whether at least one condition for resuming the RRM measurements in the next measurement window is satisfied during a pre-defined evaluation timer. If this is the case, the UE may decide itself or be instructed by the network node to ignore (or bypass, override, etc.) the previously issued skipping command and resume the RRM measurements in the next measurement window.

[0073] It should be noted that the measurement window used herein may refer to a time window in which a UE is configured to perform RRM measurements. The measurement window may be configured by a network node for the UE in accordance with different measurement configuration concepts, including (but not limited to) the existing STMC and MG configurations. FIG. 2 shows a block diagram of a UE 200 in a wireless communication network in accordance with one example embodiment. The UE 200 comprises a processor 202 and a memory 204. The memory 204 stores processor-executable instructions 206 which, when executed by the processor 202, cause the processor 202 to perform the aspects of the present disclosure, as will be described below in more detail. It should be noted that the number, arrangement, and interconnection of the constructive elements constituting the UE 200, which are shown in FIG. 2, are not intended to be any limitation of the present disclosure, but merely used to provide a general idea of how the constructive elements may be implemented within the UE 200. For example, the processor 202 may be replaced with several processors, as well as the memory 204 may be replaced with several removable and / or fixed storage devices, depending on particular applications. Furthermore, in some embodiments, the processor 202 may perform different operations required to perform data reception and transmission, such, for example, as signal modulation / demodulation, encoding / decoding, etc. Alternatively, the UE 200 may further comprise an individual transceiver which can be configured to perform the required operations for data reception and transmission based on commands from the processor 202.

[0074] The processor 202 may be implemented as a CPU, general-purpose processor, singlepurpose processor, microcontroller, microprocessor, application specific integrated circuit (ASIC), field programmable gate array (FPGA), digital signal processor (DSP), complex programmable logic device, etc. It should be also noted that the processor 202 may be implemented as any combination of one or more of the aforesaid. As an example, the processor 202 may be a combination of two or more microprocessors.

[0075] The memory 204 may be implemented as a classical nonvolatile or volatile memory used in the modern electronic computing machines. As an example, the nonvolatile memory may include Read-Only Memory (ROM), ferroelectric Random-Access Memory (RAM), Programmable ROM (PROM), Electrically Erasable PROM (EEPROM), solid state drive (SSD), flash memory, magnetic disk storage (such as hard drives and magnetic tapes), optical disc storage (such as CD, DVD and Blu-ray discs), etc. As for the volatile memory, examples thereof include Dynamic RAM, Synchronous DRAM (SDRAM), Double Data Rate SDRAM (DDR SDRAM), Static RAM, etc. The processor-executable instructions 206 stored in the memory 204 may be configured as a computer-executable program code which causes the processor 202 to perform the aspects of the present disclosure. The computer-executable program code for carrying out operations or steps for the aspects of the present disclosure may be written in any combination of one or more programming languages, such as Java, C++, Python, or the like. In some examples, the computer-executable program code may be in the form of a high- level language or in a pre-compiled form and be generated by an interpreter (also pre-stored in the memory 204) on the fly.

[0076] FIG. 3 shows a block diagram of a network node 300 in a wireless communication network in accordance with one example embodiment. The network node 300 is assumed to communicate with the UE 200 in the wireless communication network. As shown in FIG. 3, the network node 300 comprises a processor 302 and a memory 304. The memory 304 stores processor-executable instructions 306 which, when executed by the processor 302, cause the processor 302 to implement the aspects of the present disclosure, as will be described below in more detail. It should be again noted that the number, arrangement, and interconnection of the constructive elements constituting the network node 300, which are shown in FIG. 3, are not intended to be any limitation of the present disclosure, but merely used to provide a general idea of how the constructive elements may be implemented within the network node 300. In general, the processor 302, the memory 304, and the processorexecutable instructions 306 may be implemented in the same or similar manner as the processor 202, the memory 204, and the processor-executable instructions 206, respectively.

[0077] FIG. 4 shows a signaling procedure 400 for performing a network-controlled resumption of RRM measurements in a next measurement window in accordance with a first example embodiment. In the signaling procedure 400, a UE is assumed to be configured as the UE 200, a gNB is assumed to be configured as the network node 300, and the measurement window is assumed to be configured as an MG or SMTC window. The signaling procedure 400 describes the interaction between or joint operation of the UE and the gNB, which is aimed at the network-controlled resumption of the RRM measurements in the next MG / SMTC window. The signaling procedure 400 includes a step S402, in which the UE and the gNB perform capability exchange via RRC (re)configuration. In this step, the gNB also signals (e.g., together with RRC (re)configuration information) resumption-related configuration information comprising a list or a set of conditions comprising one or more conditions for resuming the RRM measurements in the next MG / SMTC window and an evaluation timer for jointly evaluating each condition of the list of conditions before the next MG. The evaluation timer defines a resumption evaluation time window, period, duration, or the like (i.e., a maximum allowed time duration for evaluation of the condition(s)). Optionally, the resumption-related configuration information may further comprise an indication whether the resumption of the RRM measurements in the next MG / SMTC window should be decided with the aid of the gNB or by the UE alone (i.e., whether the UE should apply the network-controlled or UE- controlled resumption approach to the RRM measurements in the next MG / SMTC window). The gNB may directly signal the resumption-related configuration information to the UE (e.g., during the legacy RRM and scheduling restrictions signaling procedures), or the UE may separately request it according to its capability.

[0078] As for the list of conditions, it may comprise, for example, one or more of the following conditions: a certain type of RRM measurements (e.g., RSRP) is lower than a threshold value (e.g., in dBm) upon expiration of the evaluation timer; no RRM measurement is possible to perform for a maximum allowable period of timer (during the evaluation timer); and a mobility state parameter of the UE changes by a threshold value during the evaluation timer.

[0079] The mobility state parameter may indicate whether the UE is stationary, non-stationary, slow-moving, or fast-moving (which may be determined based on a UE movement speed). As an example, the mobility state parameter may comprise one or more of the following: a maximum number of handover failures; a maximum number of radio link failures; a maximum outage time; a speed variation range (e.g., in km / h); a maximum number of beam switches between the UE and the gNB; a maximum value of a Beam Failure Indication (BFI) counter; and a maximum value of a UE panel switch counter.

[0080] In some embodiments, the list of conditions may further comprise other legacy mobility and measurement related conditions (e.g., the ones indicated in 3GPP TS 38.331), such as Event A2 related legacy parameters (e.g., threshold, hysteresis, TTT, etc.), RRM measurement relaxation conditions (e.g., cellEdgeEvaluation and lowMobilityEvaluation, etc.), Mobility state parameters (e.g., n-CellChangeMedium, n-CellChangeHigh, t-Evaluation, etc.), etc.

[0081] After the step S402, the signaling procedure proceeds to a step S404, in which the gNB transmits a skipping command to the UE to skip the RRM measurements in the next MG / SMTC window. Said skipping may involve both skipping the RRM measurements by the UE and relaxing scheduling restrictions by the gNB (i.e., prioritizing data communications over the RRM measurements) in the next MG / SMTC window. In accordance with the prior art, steps S406 and S408 should be further initiated, in which the UE and the gNB perform the RRM measurement skipping procedures after receiving the skipping command. More specifically, the gNB relaxes the RRM measurement restrictions in the next MG / SMTC window to prioritize PDCCH and PDSCH transmission, while the UE skips the RRM measurements in the next MG / SMTC window to prioritize PDCCH and PDSCH decoding (which is required for PDCCH and PDSCH reception).

[0082] However, in accordance with the present disclosure, the UE should first determine whether the skipping command is still valid. To do this, the UE should check, in a next step S410, whether one or more conditions of the list of conditions received in the step S402 are satisfied during the evaluation timer. Thus, the UE needs to trigger the evaluation timer and monitor the satisfaction or fulfillment of the condition(s). Depending on the number of conditions on the list of conditions the UE may evaluate a standalone condition or multiple conditions jointly.

[0083] Furthermore, in one example embodiment, the UE may not automatically trigger the evaluation timer in response to the skipping command, but first perform a preliminary RRM measurement before the next MG / SMTC window and check whether the preliminary RRM measurement is less than a threshold value. The UE may be configured to trigger the evaluation timer only if the preliminary RRM measurement is less than the threshold value.

[0084] In the signaling procedure 400, it is assumed that at least one condition has been satisfied during the evaluation timer, whereupon a next step S412 is initiated, in which the UE generates and transmits, to the gNB, a UE report comprising a request for ignoring the skipping command and resuming the RRM measurements in the next MG / SMTC window and the at least one condition that has been satisfied during the evaluation timer. By default, the UE indicates its intention to resume the RRM measurements by using 1 bit report signal that may be transmitted in PUCCH and multiplexed with other Uplink Control Information (UCI). Depending on timing constraints, alternatively, the UE report may be transmitted via an independent L1 / L2 signaling channel, such as being embedded in a MAC CE format.

[0085] In one embodiment, the resumption-related configuration information may further comprise a bitmap having a size equal to the number of conditions on the list of conditions and an instruction for the UE to indicate, in the bitmap, each condition that has been satisfied during the evaluation timer by using a first bit value and (if any) each condition that is not satisfied during the evaluation timer by using a second bit value. For example, the first bit value may a binary one and the second bit value may be a binary zero, or vice versa. Thus, when 2 conditions are jointly evaluated and both are verified in the step S410, the bitmap may look as follows: "11". In this embodiment, the UE is configured to include the bitmap in the UE report when sending it to the gNB in the step S412.

[0086] After the step S412, the signaling procedure 400 goes on to a step S414, in which the gNB analyzes the UE report transmitted by the UE and decides whether to accept the UE request, i.e., whether to allow the UE to resume the RRM measurements in the next MG / SMTC window. For example, if the list of conditions comprises a single condition (any one of the above-mentioned conditions) and this condition is found to be satisfied during the evaluation timer, then the gNB may know about its satisfaction from the UE report and decide to allow the UE to resume the RRM measurements in the next MG / SMTC window. If the list of conditions comprises two or more conditions previously prioritized by the gNB and some of them are found to be satisfied during the evaluation timer, the gNB may make the above decision in the step S414 depending on the priorities of the satisfied conditions. Further, in a next step S416, the gNB transmits (e.g., by using the same L1 / L2 channel as used by the UE in the step S412) a response (e.g., as DCI) to the UE, which indicates whether the UE is allowed to ignore the skipping command and resume the RRM measurements in the next MG. Such a response may be configured as an ACK / NACK message to the UE to resume.

[0087] If the ACK message is transmitted by the gNB to the UE in the step S416 (see "If True" in FIG. 4), it means that the UE is granted to resume the scheduling restrictions to prioritize the RRM measurements in the next MG / SMTC window (see a step S418). In turn, the gNB will resume scheduling restrictions in the next MG / SMTC window (see a step S420).

[0088] If the NACK message is transmitted by the gNB to the UE in the step S416 (see "If False" in FIG. 4), it means that the UE is not granted to resume the scheduling restrictions but to continue to execute the skipping command in the next MG / SMTC window (see a step S422), and the gNB will relax the scheduling restrictions in the next MG / SMTC window (see a step S424).

[0089] FIG. 5 schematically illustrates how the evaluation timer used in the signaling procedure 400 may be used to evaluate the conditions for resuming the RRM measurements in the next MG / SMTC window. In FIG. 5, it is assumed that the UE verifies the condition whether a serving cell signal level (e.g., RSRP) is lower than a threshold value and, if so, triggers the evaluation timer. Then, the UE is assumed to find that the serving cell signal level is still lower than the threshold value at the end of the evaluation time window (i.e., when the evaluation timer expires). In this case, the UE will send the UE report to the gNB with the request for resuming the RRM measurements in the next MG / SMTC window. In other words, after said verification, the UE will prefer to prioritize the RRM measurements over PDCCH / PDSCH decoding of PUCCH / PUSCH transmission. Therefore, the skipping command previously received by the UE may be put on hold.

[0090] FIG. 6 shows a signaling procedure 600 for performing the network-controlled resumption of RRM measurements in the next measurement window in accordance with a second example embodiment. In the signaling procedure 600, a UE is again assumed to be configured as the UE 200, a gNB is again assumed to be configured as the network node 300, and the measurement window is again assumed to be configured as an MG or SMTC window. Like the signaling procedure 400, the signaling procedure 600 describes the interaction between or joint operation of the UE and the gNB, which is aimed at the network-controlled resumption of the RRM measurements in the next MG / SMTC window.

[0091] The signaling procedure 600 includes steps S602-S608, which may be performed in the same or similar manner as the steps S402-S408, respectively. More specifically, in the step S602, the UE and the gNB perform the capability exchange via the RRC (re)configuration, and the gNB also signals (e.g., together with the RRC (re)configuration information) the same resumption-related configuration information comprising the list of conditions comprising one or more conditions for resuming the RRM measurements in the next MG / SMTC window and the evaluation timer for jointly evaluating each condition of the list of conditions before the next MG / SMTC window. The list of conditions may comprise one or more of the above- mentioned conditions. In the step S604, the gNB transmits the skipping command to the UE to skip the RRM measurements in the next MG / SMTC window. Next, the steps S606 and S608 should be initiated in accordance with the legacy RRM measurement skipping procedures.

[0092] However, in accordance with the present disclosure and unlike the signaling procedure 400, the signaling procedure 600 further goes on to a step S610, in which the gNB itself determines whether to ignore the skipping command and resume the RRM measurements in the next MG / SMTC window. Thus, the condition evaluation step is performed on the network side because the gNB may use RRM measurement reports from the UE for said condition evaluation. The UE may additionally be configured by the gNB (e.g., in the step S602) to continuously provide such RRM measurement reports during the evaluation timer. In this case, the UE report will not be necessarily needed and signaling cost is relatively lower compared to the signaling procedure 400.

[0093] In a next step S612, the gNB generates and transmits (e.g., via an independent L1 / L2 channel) either a first message or a second message to the UE. The first message may be configured as an ACK message indicating that the UE is allowed to ignore the skipping command and resume the RRM measurements in the next MG / SMTC window. The second message may be configured as a NACK message indicating that the UE needs to execute the skipping command and skip the RRM measurements in the next MG / SMTC window. If the first (ACK) message is transmitted by the gNB to the UE in the step S612, the UE will resume the scheduling restrictions to prioritize the RRM measurements in the next MG / SMTC window (see a step S614), and the gNB will resume the scheduling restrictions in the next MG / SMTC window (see a step S616).

[0094] If the second (NACK) is transmitted by the gNB to the UE in the step S612 (this situation is not shown in FIG. 6), the UE will not resume the scheduling restrictions but to continue to execute the skipping command, and the gNB will relax the scheduling restrictions in the next MG / SMTC window.

[0095] FIG. 7 shows a signaling procedure 700 for performing a UE-controlled resumption of RRM measurements in a next measurement window in accordance with a first example embodiment. In the signaling procedure 700, a UE is again assumed to be configured as the UE 200, a gNB is again assumed to be configured as the network node 300, and the measurement window is again assumed to be configured as an MG or SMTC window. Unlike the signaling procedures 400 and 600, the signaling procedure 700 describes the interaction between or joint operation of the UE and the gNB, which is aimed at the UE-controlled resumption of the RRM measurements in the next MG / SMTC window.

[0096] The signaling procedure 700 includes steps S702-S710, which may be performed in the same or similar manner as the steps S402-S410, respectively. More specifically, in the step S702, the UE and the gNB perform the capability exchange via the RRC (re)configuration, and the gNB also signals (e.g., together with the RRC (re)configuration information) the same resumption-related configuration information comprising the list of conditions comprising one or more conditions for resuming the RRM measurements in the next MG / SMTC window and the evaluation timer for jointly evaluating each condition of the list of conditions before the next MG / SMTC window. The list of conditions may comprise one or more of the above- mentioned conditions. In the step S704, the gNB transmits the skipping command to the UE to skip the RRM measurements in the next MG / SMTC window. Next, the steps S706 and S708 should be initiated in accordance with the legacy RRM measurement skipping procedures. However, in accordance with the present disclosure, the UE further verify the validity of the skipping command in the step S710 by performing the above-mentioned condition evaluation during the evaluation timer. In the signaling procedure 700, it is assumed that at least one condition of the list of conditions has been satisfied during the evaluation timer, whereupon a next step S712 is initiated, in which the UE generates and transmits, to the gNB, a UE report (e.g., via an independent L1 / L2 channel). Unlike the UE report transmitted by the UE in the step S412 of the signaling procedure 400, the UE report now comprises not a request, but an indication that the UE is going to / will ignore the skipping command and resume the RRM measurements in the next MG / SMTC window. In the meantime, the UE report transmitted in the step S712 may further comprise a bitmap indicating the satisfied and (if any) unsatisfied conditions in the same manner as discussed above with respect to the signaling procedure 400. In the signaling procedure 700, it is also assumed that the UE report is always successfully transmitted and received by the gNB. Given this, the UE will autonomously resume the scheduling restrictions to prioritize the RRM measurement in the next MG / SMTC window (see a step S714), and the gNB will resume the scheduling restrictions in the next MG / SMTC window in accordance with the UE report (see a step S716).

[0097] It should be noted that, if the UE finds no satisfied condition in the step S710 (this situation is not shown in FIG. 7), then it will not autonomously resume the scheduling restrictions but to continue to execute the skipping command in the next MG / SMTC window, and the gNB will relax the scheduling restrictions in the next MG / SMTC window.

[0098] FIG. 8 shows a signaling procedure 800 for performing the UE-controlled resumption of RRM measurements in the next measurement window in accordance with a second example embodiment. In the signaling procedure 800, a UE is again assumed to be configured as the UE 200, a gNB is again assumed to be configured as the network node 300, and the measurement window is again assumed to be configured as an MG or SMTC window. Like the signaling procedure 700, the signaling procedure 800 describes the interaction between or joint operation of the UE and the gNB, which is aimed at the UE-controlled resumption of the RRM measurements in the next MG / SMTC window.

[0099] The signaling procedure 800 includes steps S802-S810, which may be performed in the same or similar manner as the steps S402-S410, respectively. More specifically, in the step S802, the UE and the gNB perform the capability exchange via the RRC (re)configuration, and the gNB also signals (e.g., together with the RRC (re)configuration information) the same resumption-related configuration information comprising the list of conditions comprising one or more conditions for resuming the RRM measurements in the next MG / SMTC window and the evaluation timer for jointly evaluating each condition of the list of conditions before the next MG / SMTC window. The list of conditions may comprise one or more of the above- mentioned conditions. In the step S804, the gNB transmits the skipping command to the UE to skip the RRM measurements in the next MG / SMTC window. Next, the steps S806 and S808 should be initiated in accordance with the legacy RRM measurement skipping procedures. However, in accordance with the present disclosure, the UE further verify the validity of the skipping command in the step S810 by performing the above-mentioned condition evaluation during the evaluation timer.

[0100] In the signaling procedure 800, it is again assumed that at least one condition of the list of conditions has been satisfied during the evaluation timer, whereupon a next step S812 is initiated, which is similar to the step S712 of the signaling procedure 700. In other words, the UE generates and transmits, to the gNB, a UE report (e.g., via an independent L1 / L2 channel) that comprises not a request (like in the signaling procedure 400), but an indication that the UE is going to / will ignore the skipping command and resume the RRM measurements in the next MG / SMTC window. It should be also noted that the UE report transmitted in the step S812 may further comprise a bitmap indicating the satisfied and (if any) unsatisfied conditions in the same manner as discussed above with respect to the signaling procedure 400.

[0101] Unlike the signaling procedure 700, the signaling procedure 800 covers two outcomes: (i) the UE report is successfully transmitted and received by the gNB, and (ii) the UE report is lost (i.e., unsuccessfully transmitted and received by the gNB). When outcome (i) takes place, steps S814 and S816 are performed, which are similar to the steps S714 and S716, respectively. In other words, in case of outcome (i), the UE will autonomously resume the scheduling restrictions to prioritize the RRM measurement in the next MG / SMTC window (see the step S814), and the gNB will resume the scheduling restrictions in the next MG in accordance with the UE report (see the step S816). When outcome (ii) takes place, the UE will also autonomously resume the scheduling restrictions to prioritize the RRM measurements in the next MG / SMTC window (see a step S818), but the gNB cannot resume the scheduling restrictions in the next MG / SMTC window due to the unsuccessful transmission and reception of the UE report. Thus, outcome (ii) may lead to the inconsistency between the gNB and the UE due to the lost UE report.

[0102] It should be noted that each step or operation of the signaling procedures 400, 600-800, or any combinations of the steps or operations, can be implemented by various means, such as hardware, firmware, and / or software. As an example, one or more of the steps or operations described above can be embodied by processor executable instructions, data structures, program modules, and other suitable data representations. Furthermore, the processorexecutable instructions which embody the steps or operations described above can be stored on a corresponding data carrier and executed by the processors 202 and 302, respectively. This data carrier can be implemented as any computer-readable storage medium configured to be readable by said at least one processor to execute the processor executable instructions. Such computer-readable storage media can include both volatile and nonvolatile media, removable and non-removable media. By way of example, and not limitation, the computer-readable media comprise media implemented in any method or technology suitable for storing information. In more detail, the practical examples of the computer-readable media include, but are not limited to information-delivery media, RAM, ROM, EEPROM, flash memory or other memory technology, CD-ROM, digital versatile discs (DVD), holographic media or other optical disc storage, magnetic tape, magnetic cassettes, magnetic disk storage, and other magnetic storage devices.

[0103] Although the example embodiments of the present disclosure are described herein, it should be noted that any various changes and modifications could be made in the embodiments of the present disclosure, without departing from the scope of legal protection which is defined by the appended claims. In the appended claims, the word "comprising" does not exclude other elements or operations, and the indefinite article "a" or "an" does not exclude a plurality. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage.

Claims

CLAIMS1. A User Equipment (UE) in a wireless communication network, 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: receive configuration information from a network node in the wireless communication network, the configuration information comprising an instruction for the UE to continuously transmit at least one of a Radio Resource Management (RRM) measurement and a mobility state parameter to the network node during an evaluation timer before a next measurement window; receive a skipping command from the network node, the skipping command instructing the UE to skip the RRM measurement in the next measurement window; trigger the evaluation timer; continuously transmit said at least one of the RRM measurement and the mobility state parameter to the network node until the evaluation timer expires; and receive, from the network node, one of: a first message indicating that the UE is allowed to ignore the skipping command and resume the RRM measurement in the next measurement window; and a second message indicating that the UE needs to execute the skipping command in the next measurement window.

2. The UE of claim 1, wherein the UE is further caused, upon receiving the skipping command, to: perform the RRM measurement before the next measurement window; determine whether the RRM measurement is less than a threshold value; and if the RRM measurement is less than the threshold value, trigger the evaluation timer.

3. The UE of claim 1 or 2, wherein the mobility state parameter of the UE comprises at least one of:a maximum number of handover failures; a maximum number of radio link failures; a maximum outage time; a speed variation range; a maximum number of beam switches between the UE and the network node; a maximum value of a Beam Failure Indication (BFI) counter; and a maximum value of a UE panel switch counter.

4. The UE of any one of claims 1 to 3, wherein the UE is further caused, before receiving the configuration information, to transmit a request for the configuration information to the network node.

5. A network node in a wireless communication network, 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 configuration information to a User Equipment (UE) in the wireless communication network, the configuration information comprising an instruction for the UE to continuously transmit at least one of a Radio Resource Management (RRM) measurement and a mobility state parameter to the network node during an evaluation timer before a next measurement window; transmit a skipping command to the UE, the skipping command instructing the UE to skip the RRM measurement in the next measurement window; continuously receive, from the UE, said at least one of the RRM measurement and the mobility state parameter during the evaluation timer; based on said at least one of the RRM measurement and the mobility state parameter, determine whether at least one condition for resuming the RRM measurement in the next measurement window has been satisfied during the evaluation timer; and transmit, to the UE, a first message if the at least one condition for resuming the RRM measurement in the next measurement window has been satisfied during the evaluation timer or a second message if the at least one condition for resumingthe RRM measurement in the next measurement window has not been satisfied during the evaluation timer, the first message indicating that the UE is allowed to ignore the skipping command and resume the RRM measurement in the next measurement window, and the second message indicating that UE needs to execute the skipping command in the next measurement window.

6. The network node of claim 5, wherein the at least one condition comprises at least one of: the RRM measurement is lower than a threshold value upon expiration of the evaluation timer; no RRM measurement is possible to perform for a maximum allowable period of time; and the mobility state parameter of the UE changes by a threshold value during the evaluation timer.

7. The network node of claim 5 or 6, wherein the mobility state parameter of the UE comprises at least one of: a maximum number of handover failures; a maximum number of radio link failures; a maximum outage time; a speed variation range; a maximum number of beam switches between the UE and the network node; a maximum value of a Beam Failure Indication (BFI) counter; and a maximum value of a UE panel switch counter.

8. The network node of any one of claims 5 to 7, wherein the network node is caused to transmit each of the first message and the second message via an independent LI or L2 signaling channel.

9. The network node of any one of claims 5 to 8, wherein the network node is further caused to: receive a request for the configuration information from the UE; andin response to the request, transmit the configuration information to the UE.

10. A method for operating a User Equipment (UE) in a wireless communication network, comprising: receiving configuration information from a network node in the wireless communication network, the configuration information comprising an instruction for the UE to continuously transmit at least one of a Radio Resource Management (RRM) measurement and a mobility state parameter to the network node during an evaluation timer before a next measurement window; receiving a skipping command from the network node, the skipping command instructing the UE to skip the RRM measurement in the next measurement window; triggering the evaluation timer; continuously transmitting said at least one of the RRM measurement and the mobility state parameter to the network node until the evaluation timer expires; and receiving, from the network node, one of: a first message indicating that the UE is allowed to ignore the skipping command and resume the RRM measurement in the next measurement window; and a second message indicating that the UE needs to execute the skipping command in the next measurement window.

11. A method for operating a network node in a wireless communication network, comprising: transmitting configuration information to a User Equipment (UE) in the wireless communication network, the configuration information comprising an instruction for the UE to continuously transmit at least one of a Radio Resource Management (RRM) measurement and a mobility state parameter to the network node during an evaluation timer before a next measurement window; transmitting a skipping command to the UE, the skipping command instructing the UE to skip the RRM measurement in the next measurement window; continuously receiving, from the UE, said at least one of the RRM measurement and the mobility state parameter during the evaluation timer;based on said at least one of the RRM measurement and the mobility state parameter, determining whether at least one condition for resuming the RRM measurement in the next measurement window has been satisfied during the evaluation timer; and transmitting, to the UE, a first message if the at least one condition for resuming the RRM measurement in the next measurement window has been satisfied during the evaluation timer or a second message if the at least one condition for resuming the RRM measurement in the next measurement window has not been satisfied during the evaluation timer, the first message indicating that the UE is allowed to ignore the skipping command and resume the RRM measurement in the next measurement window, and the second message indicating that UE needs to execute the skipping command in the next measurement window.

12. A computer program product comprising a computer-readable storage medium, wherein the computer-readable storage medium stores a computer code which, when executed by at least one processor, causes the at least one processor to perform the method according to claim 10.

13. A computer program product comprising a computer-readable storage medium, wherein the computer-readable storage medium stores a computer code which, when executed by at least one processor, causes the at least one processor to perform the method according to claim 11.

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