Beam selection in RACH-less conditional LTM execution

Abstract

Systems and methods for beam selection in Random Access Channel (RACH)-less Conditional L1 / L2-Triggered Mobility (CLTM) execution are provided. In some embodiments, a method at a User Equipment (UE) for performing beam selection during a CLTM execution procedure (which may be considered as an LTM Cell Switch upon fulfillment of an LTM execution condition) based on one or more criteria / rules is provided.

Description

BEAM SELECTION IN RACH-LESS CONDITIONAL LTM EXECUTIONTECHNICAL FIELD

[0001] The present disclosure relates generally to beam selection.BACKGROUND

[0002] Ll / L2-Triggered Mobility (LTM) in Rel-18

[0003] LTM is a procedure in which a gNB receives LI measurement report(s) from a UE, and on their basis the gNB changes UE serving cell by a cell switch command signaled via a MAC CE. The cell switch command indicates an LTM candidate configuration that the gNB previously prepared and provided to the UE through RRC signaling. Then the UE switches to the target configuration according to the cell switch command (See, e.g., TS 38.300 V18.0.0 (2023-12); 3rd Generation Partnership Project; Technical Specification Group Radio Access Network; NR; NR and NG-RAN Overall Description; Stage 2 (Release 18)).

[0004] When configured by the network, it is possible to activate Transmission Configuration Indication (TCI) states of one or multiple cells that are different from the current serving cell. This is sometimes called pre-activation of a candidate TCI state, since this is pre- activating a TCI state of an LTM candidate cell before the UE receives the LTM cell switch command i.e., before the LTM cell switch procedure. For instance, the TCI states of the LTM candidate cells can be activated in advance before any of those cells become the serving cell. This allows the UE to be downlink (DL) synchronized with those cells (or DL pre-sync), thereby facilitating a faster cell switch to one of those cells when cell switch is triggered.

[0005] Cell switch command is conveyed in a MAC CE, which contains the necessary information to perform the LTM cell switch. The overall procedure for LTM is shown in Figure 1.

[0006] The procedure for LTM is as follows:

[0007] 1. The UE sends a MeasurementReport message to the gNB. The gNB decides to configure LTM and initiates LTM preparation.

[0008] 2. The gNB transmits an RRCReconfiguration message to the UE including the LTM candidate configurations.

[0009] 3. The UE stores the LTM candidate configurations and transmits anRRCReconfigurationComplete message to the gNB.

[0010] 4a. The UE performs DL synchronization with the candidate cell(s) before receiving the cell switch command. This is triggered upon reception by the UE of a “Candidate Cell TCIStates Activation / Deactivation MAC CE” for LTM candidate cell(s) configured in CandidateTCI- State and CandidateTCI-UL-State. Upon reception, in the UE’ s MAC entity, the UE’ s MAC entity receives a Candidate Cell TCI States Activation / Deactivation MAC CE on a Serving Cell, the UE indicate to lower layers the information regarding the Candidate Cell TCI States Activation / Deactivation MAC CE.

[0011] 4b. The UE may also perform UL pre- synchronization with the LTM candidate cell(s) if it receives the PDCCH order for early timing advance (TA) acquisition for those candidate cells.

[0012] 5. The UE performs LI measurements on the configured candidate cell(s) and transmits LI measurement reports to the gNB. LI measurement should be performed as long as RRC reconfiguration (step 2) is applicable.

[0013] 6. The gNB decides to execute cell switch to a target cell and transmits a MAC CE triggering cell switch by including the candidate configuration index of the target cell. The UE switches to the target cell and applies the configuration indicated by candidate configuration index.

[0014] 7. The UE performs the random-access procedure towards the target cell, if UE does not have valid TA of the target cell. Otherwise if the UE receives a valid TA value in LTM cell switch command using early TA acquisition method in step 4b, the UE is not required to perform random- access.

[0015] 8. The UE completes the LTM cell switch procedure by sendingRRCReconfigurationComplete message to target cell. If the UE has performed a RA procedure in step 7, the UE considers that LTM cell switch execution is successfully completed when the random-access procedure is successfully completed. For RACH-less LTM, the UE considers that LTM cell switch execution is successfully completed when the UE determines that the network has successfully received its first UL data.

[0016] Conditional LTM in ReL 19

[0017] LTM was introduced in Rel-18 and can offer improvements in handover latency and interruption time compared to Layer 3 based mobility. However, LTM as introduced in Rel-18 also has a number of limitations compared to Layer 3 mobility. The Rel-19 work item aims to remove a number of these limitations. Layer 3 mobility has evolved over several releases and includes Conditional handover (CHO) and other conditional mobility procedures (CP AC, SCPAC) were developed to achieve high robustness by enabling the procedure to be executed without necessitating a signaling exchange with source cell beforehand. LTM as introduced in Rel-18 offers short interruption time but not with the same level of robustness as the conditional L3mobility procedures. In Rel-19, enhancements should be specified so that the system can benefit from both the high robustness of CHO and short interruption offered by LTM.

[0018] One such attempt for providing the benefits of both the LTM and CHO is the Conditional LTM, which is proposed to be a part of Rel-19 Mobility enhancements. Regarding conditional LTM, the following objectives have been captured in (RP-234036, New WID: NR mobility enhancements Phase 4, 3GPP TSG RAN Meeting #102, Edinburgh, Scotland, December 11- 15, 2023):

[0019] Specify support of conditional LTM [RAN2, RAN3, RANI] a. Specify UE evaluated conditions for triggering LTM. b. Aim to support conditional LTM including subsequent LTM

[0020] Improved systems and methods for beam selection are needed.SUMMARY

[0021] Systems and methods for beam selection in Random Access Channel (RACH)-less Conditional Ll / L2-Triggered Mobility (CLTM) execution are provided. In some embodiments, a method at a User Equipment (UE) for performing beam selection during a CLTM execution procedure (which may be considered as an LTM Cell Switch upon fulfillment of an LTM execution condition) based on one or more criteria / rules is provided.

[0022] In some embodiments, the UE is configured with at least one CLTM candidate cell, each having an associated CLTM Candidate cell configuration (e.g., to be applied and used by the UE in CLTM execution, like an RRC Reconfiguration or IES of an RRC Reconfiguration), and an associated LTM execution condition (also called a CLTM execution condition). In some embodiments, the CLTM execution condition is “a measurement of the LTM candidate cell (e.g., a beam measurement) becomes an offset (or threshold) better than a measurement of the serving cell (e.g., a beam measurement)”. In some embodiments, an LTM execution condition is configured at the UE by the UE receiving a measurement configuration identifier (e.g., a CSI reporting configuration identifier) associated to one or more measurements.

[0023] When the CLTM execution condition is fulfilled, the UE selects a CLTM candidate cell for which the CLTM execution condition has been fulfilled and applies the CLTM candidate cell configuration associated to the selected CLTM candidate cell. For the selected CLTM candidate cell, the UE determines to perform a RACH-less CLTM execution (e.g., when a previously provided Timing Advanced (TA) value is valid) and / or selects a beam (e.g., RS, SSB, CSLRS) of the selected CLTM candidate cell based on one or more of the following criteria / rules:

[0024] Based on the availability of a valid UL grant; Based on the availability of the Scheduling Request (SR) configuration; Based on a measurement quantity e.g., RSRP threshold, RSRQ threshold, SINR threshold, highest quantity, etc.; Based on an availability of a pre- activated TCI state; Based on the Downlink (DL) synchronization ‘status’ associated to a beam (e.g., SSB) of the selected CLTM candidate cell; Based on the Uplink (UL) synchronization ‘status’ associated to a beam of the selected CLTM candidate cell; and / or based on the contention free random access dedicated configuration (e.g., CFRA) associated to a beam of the selected CLTM candidate cell.BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The accompanying drawing figures incorporated in and forming a part of this specification illustrate several aspects of the disclosure, and together with the description serve to explain the principles of the disclosure.

[0026] Figure 1 illustrates an overall procedure for LTM;

[0027] Figure 2 shows an example of a communication system in accordance with some embodiments of the present disclosure;

[0028] Figure 3 illustrates a method performed by a User Equipment (UE), according to some embodiments of the present disclosure;

[0029] Figure 4 illustrates a method performed by a network node, according to some embodiments of the present disclosure;

[0030] Figure 5 shows a UE in accordance with some embodiments of the present disclosure;

[0031] Figure 6 shows a network node in accordance with some embodiments of the present disclosure; and

[0032] Figure 7 is a block diagram illustrating a virtualization environment in which functions implemented by some embodiments may be virtualized in accordance with some embodiments of the present disclosure.DETAILED DESCRIPTION

[0033] The embodiments set forth below represent information to enable those skilled in the art to practice the embodiments and illustrate the best mode of practicing the embodiments. Upon reading the following description in light of the accompanying drawing figures, those skilled in the art will understand the concepts of the disclosure and will recognize applications of these concepts not particularly addressed herein. It should be understood that these concepts and applications fall within the scope of the disclosure.

[0034] Some of the embodiments contemplated herein will now be described more fully with reference to the accompanying drawings. Embodiments are provided by way of example to convey the scope of the subject matter to those skilled in the art.

[0035] There currently exist certain challenge(s). For LTM legacy, the UE performs a RACH- less LTM Cell Switch (i.e., without performing random access in response to the LTM Cell Switch command) when the UE had been previously configured for early UL sync, received a Timing Advanced (TA) value in the LTM Cell Switch command which is applied at the execution. The LTM Cell Switch command also includes a Transmission Configuration Indication (TCI) state ID, indicating to the UE what TCI state of the LTM candidate cell (also indicated in the LTM Cell Switch command) is to be activated. Such a TCI state ID may also be considered as a ‘beam indication’, since it indicates which downlink (DL) beam the UE is to ‘align’ or synchronize with, to when monitoring Physical Downlink Control Channel (PDCCH) for dynamic grant reception and / or to transmit a Scheduling Request (SR) on the Physical Uplink Control Channel (PUCCH) and / or uplink (UL) data e.g., the RRC Reconfiguration complete message over an UL grant on the Physical Uplink Shared Channel (PUSCH), in the LTM candidate cell (which becomes the target in the LTM cell Switch). In other words, in LTM Rel-18 solution, the UE selects the beam indicated in the TCI state ID included in the LTM Cell Switch command to perform the LTM execution in response to the LTM Cell Switch command.

[0036] A problem in ReL 19, for Conditional LTM (CLTM), is that in CLTM the UE does not trigger the LTM Cell Switch upon reception of an LTM Cell Switch command, but in response to the fulfillment of a Conditional LTM execution condition e.g., when a measurement on an LTM candidate cell becomes an offset better than the serving cell (like the PCell). Then, it is not clear how the UE performs beam selection and, consequently, how the UE transmits an SR over PUCCH and / or UL data (e.g., RRC Reconfiguration Complete) over a configured UL grant on PUSCH; or / and, how to monitor PDCCH for receiving the dynamic grant in the target cell selected in Conditional LTM execution.

[0037] Certain aspects of the disclosure and their embodiments may provide solutions to these or other challenges. Systems and methods for beam selection in RACH-less Conditional LTM execution are provided. In some embodiments, a method at a User Equipment (UE) for performing beam selection during a Conditional LTM (CLTM) execution procedure (which may be considered as an LTM Cell Switch upon fulfillment of an LTM execution condition) based on one or more criteria / rules is provided.

[0038] In some embodiments, the UE is configured with at least one CLTM candidate cell, each having an associated CLTM Candidate cell configuration (e.g., to be applied and used by theUE in CLTM execution, like an RRC Reconfiguration or IES of an RRC Reconfiguration), and an associated LTM execution condition (also called a CLTM execution condition). In some embodiments, the CLTM execution condition is “a measurement of the LTM candidate cell (e.g., a beam measurement) becomes an offset (or threshold) better than a measurement of the serving cell (e.g., a beam measurement)”. In some embodiments, an LTM execution condition is configured at the UE by the UE receiving a measurement configuration identifier (e.g., a CSI reporting configuration identifier) associated to one or more measurements.

[0039] When the CLTM execution condition is fulfilled, the UE selects a CLTM candidate cell for which the CLTM execution condition has been fulfilled and applies the CLTM candidate cell configuration associated to the selected CLTM candidate cell. For the selected CLTM candidate cell, the UE determines to perform a RACH-less CLTM execution (e.g., when a previously provided Timing Advanced (TA) value is valid) and / or selects a beam (e.g., RS, SSB, CSLRS) of the selected CLTM candidate cell based on one or more of the following criteria / rules:

[0040] Based on the availability of a valid UL grant; Based on the availability of the Scheduling Request (SR) configuration; Based on a measurement quantity e.g., RSRP threshold, RSRQ threshold, SINR threshold, highest quantity, etc.; Based on an availability of a pre- activated TCI state; Based on the Downlink (DL) synchronization ‘status’ associated to a beam (e.g., SSB) of the selected CLTM candidate cell; Based on the Uplink (UL) synchronization ‘status’ associated to a beam of the selected CLTM candidate cell; and / or based on the contention free random access dedicated configuration (e.g., CFRA) associated to a beam of the selected CLTM candidate cell.

[0041] Based on the availability of a valid UL grant: In other words, when there are multiple beams (e.g., SSBs) in the selected CLTM candidate cell (also called CLTM candidate cell), the UE selects the beam for which an UL grant on an UL physical channel (e.g., Physical UL Shared Channel - PUSCH) has been received by the UE. The benefit is that the UE would transmit a complete message (e.g., RRC Reconfiguration Complete message) much faster, since the UE would not need first send a Scheduling Request on PUCCH, monitor PDCCH and obtain an UL grant. Instead, the UE selects a beam (SSB) with an associated UL grant and directly transmits the RRC Reconfiguration complete message.

[0042] Based on the availability of the Scheduling Request (SR) configuration: In other words, when there are multiple beams (e.g., SSBs) in the selected CLTM candidate cell, the UE selects the one for which an SR configuration with the PUCCH resources has been provided. The benefit is that the UE can utilize the SR configuration and the allocated PUCCH resources for sending SR and then obtain an UL grant via PDCCH, without initiating random-access. In otherwords, the UE can select a beam (SSB) with SR configuration available such that the UE can execute a RACH-less cell switch.

[0043] Based on a measurement quantity e.g., RSRP threshold, RSRQ threshold, SINR threshold, highest quantity, etc.: In other words, when there are multiple beams (e.g., SSBs) in the selected CLTM candidate cell, the UE selects the beam (e.g., SSB) based on a measurement quantity of the beam(s) e.g., UE selects a beam above a threshold, such as selecting an SSB with an SS-RSRP above a threshold. The benefit is that the UE transmits the RRC Reconfiguration complete in a robust beam, and network is less likely to trigger a beam switching shortly after the LTM Cell Switch, or the UE to detect a beam failure right after the LTM Cell Switch.

[0044] Based on an availability of a pre-activated TCI state: In other words, when there are multiple beams (e.g., SSBs) in the selected CLTM candidate cell, the UE selects a beam (e.g., SSB) of the selected LTM candidate cell associated to a pre-activated TCI state. Being associated in this context means, for example, that the beam (SSB) is configured as Quasi-Co-Location (QCL) source of the TCI state which has been pre-activated. In some embodiments, the selected beam is QCLed with the SSB and the TCI state. A TCI state of an LTM candidate cell is pre-activated when the UE receives a command from a serving cell (e.g., a Candidate Cell TCI States Activation / Deactivation MAC CE) while configured with Conditional LTM, before the fulfillment of the LTM execution condition for that LTM candidate cell.

[0045] Based on the Downlink (DL) synchronization ‘status’ associated to a beam (e.g., SSB) of the selected CLTM candidate cell: In other words, when there are multiple beams (e.g., SSBs) in the selected LTM candidate cell, the UE selects a beam (SSB) of the selected LTM candidate cell for which the UE is DL synchronized. In one option, the UE DL synchronizes with a beam of the selected candidate cell before the fulfillment of the CLTM execution condition(s), so that this may be called a DL pre-synchronization, or Early DL sync.

[0046] Based on the Uplink (UL) synchronization ‘status’ associated to a beam of the selected CLTM candidate cell: In other words, when there are multiple beams (e.g., SSBs) in the selected LTM candidate cell, the UE selects a beam (SSB) of the selected LTM candidate cell for which the UE is UL synchronized. In one option, the UE UL synchronizes with a beam of the selected cell before the fulfillment of the CLTM execution condition(s), so that this may be called a UL pre-synchronization or Early UL sync.

[0047] Based on the contention free random access dedicated configuration (e.g., CFRA) associated to a beam of the selected CLTM candidate cell: In other words, when there are multiple beams (e.g., SSBs) in the selected LTM candidate cell, the UE selects a beam (SSB) which is associated to a contention free random-access configuration associated to the selected LTMcandidate cell. In such a case, the dedicated random-access configuration is different from the random-access configuration used for the early UL synchronization procedure. This dedicated random-access configuration is the random-access configuration that is used by the UE to perform a contention free random-access procedure (CFRA). In one option, the UE performs a RACH- based solution using the CFRA resources associated to the selected beam of the CLTM candidate cell. In another option, the UE selects the beam of the CLTM candidate cell with associated CFRA resources in case the RACH-less procedure fails, and the UE is allowed to perform a RACH-based solution towards the same selected beam. In another option, the UE selects the beam of the CLTM candidate cell with associated CFRA resources in case the RACH-less procedure is not possible e.g., when time alignment timer has expired. Then, the UE needs to perform a RACH-based solution towards a selected beam of a selected CLTM candidate cell.

[0048] Certain embodiments may provide one or more of the following technical advantage(s). One advantage of the embodiments is that the method enables a RACH-less LTM Cell Switch for Conditional LTM execution, which reduces the interruption time in a procedure meant to improve the connection robustness.

[0049] For the different criteria, there may be different specific benefits. In the case the UE selects a beam (SSB) based on an availability of a valid UL grant, the benefit is that the UE would transmit the RRC Reconfiguration complete message much faster, since the UE would not need first send a SR on PUCCH, monitor PDCCH and obtain an UL grant. Instead, the UE selects a beam (SSB) with an associated UL grant and directly transmits the RRC Reconfiguration complete message.

[0050] In a further option, the UE selects a beam (SSB) based on the presence of the SR configuration and the associated PUCCH resources for sending the SR directly without performing any random-access.

[0051] In the case the UE selects a beam (SSB) based on a measurement quantity, e.g., beam with highest RSPR value, the benefit is that the UE transmits the RRC Reconfiguration complete in the most robust beam, and network is less likely to trigger a beam switching shortly after the LTM Cell Switch. Or, if the UE selects a beam above a threshold, the beam is robust, so that there is a lower likelihood of a Beam failure detection and / or a radio link failure after the LTM Cell Switch.

[0052] In the case the UE selects a beam (SSB) based on the status of a pre-configured TCI state e.g., whether the TCI state is activated and / or deactivated, is that the UE selects the beam (SSB) for which the UE is DL synchronized i.e., is has a pre-activated TCI state, which saves time for the UE which is not required to perform further SSB measurements on the LTM candidate cellafter conditions are fulfilled. The benefit is also on the network side, which is monitoring the beam(s) (and / or UL channel(s) associated) for which TCI state(s) have been pre-activated. In a further option, the UE selects a beam (SSB) based on the SSB(s) indicated within a contention free random access configuration. In such a case, the UE selects a beam (SSB) which is among the one indicated in the CFRA RACH configuration. In this case, if more than one SSB is indicated in the CFRA RACH configuration, the UE may select the SSB according to the one or more rule described above.

[0053] The teachings of certain embodiments may improve the e.g., data rate, latency, power consumption, etc.

[0054] Figure 2 shows an example of a communication system 200 in accordance with some embodiments.

[0055] In the example, the communication system 200 includes a telecommunication network 202 that includes an access network 204, such as a Radio Access Network (RAN), and a core network 206, which includes one or more core network nodes 208. The access network 204 includes one or more access network nodes, such as network nodes 210A and 210B (one or more of which may be generally referred to as network nodes 210), or any other similar Third Generation Partnership Project (3GPP) access nodes or non-3GPP Access Points (APs). Moreover, as will be appreciated by those of skill in the art, a network node is not necessarily limited to an implementation in which a radio portion and a baseband portion are supplied and integrated by a single vendor. Thus, it will be understood that network nodes include disaggregated implementations or portions thereof. For example, in some embodiments, the telecommunication network 202 includes one or more Open-RAN (ORAN) network nodes. An ORAN network node is a node in the telecommunication network 202 that supports an ORAN specification (e.g., a specification published by the O-RAN Alliance, or any similar organization) and may operate alone or together with other nodes to implement one or more functionalities of any node in the telecommunication network 202, including one or more network nodes 210 and / or core network nodes 208.

[0056] Examples of an ORAN network node include an Open Radio Unit (O-RU), an Open Distributed Unit (O-DU), an Open Central Unit (O-CU), including an O-CU Control Plane (O- CU-CP) or an O-CU User Plane (O-CU-UP), a RAN intelligent controller (near-real time or non- real time) hosting software or software plug-ins, such as a near-real time control application (e.g., xApp) or a non-real time control application (e.g., rApp), or any combination thereof (the adjective “open” designating support of an ORAN specification). The network node may support a specification by, for example, supporting an interface defined by the ORAN specification, such asan Al, Fl, Wl, El, E2, X2, Xn interface, an open fronthaul user plane interface, or an open fronthaul management plane interface. Moreover, an ORAN access node may be a logical node in a physical node. Furthermore, an ORAN network node may be implemented in a virtualization environment (described further below) in which one or more network functions are virtualized. For example, the virtualization environment may include an O-Cloud computing platform orchestrated by a Service Management and Orchestration Framework via an 0-2 interface defined by the 0-RAN Alliance or comparable technologies. The network nodes 210 facilitate direct or indirect connection of User Equipment (UE), such as by connecting UEs 212A, 212B, 212C, and 212D (one or more of which may be generally referred to as UEs 212) to the core network 206 over one or more wireless connections.

[0057] Example wireless communications over a wireless connection include transmitting and / or receiving wireless signals using electromagnetic waves, radio waves, infrared waves, and / or other types of signals suitable for conveying information without the use of wires, cables, or other material conductors. Moreover, in different embodiments, the communication system 200 may include any number of wired or wireless networks, network nodes, UEs, and / or any other components or systems that may facilitate or participate in the communication of data and / or signals whether via wired or wireless connections. The communication system 200 may include and / or interface with any type of communication, telecommunication, data, cellular, radio network, and / or other similar type of system.

[0058] The UEs 212 may be any of a wide variety of communication devices, including wireless devices arranged, configured, and / or operable to communicate wirelessly with the network nodes 210 and other communication devices. Similarly, the network nodes 210 are arranged, capable, configured, and / or operable to communicate directly or indirectly with the UEs 212 and / or with other network nodes or equipment in the telecommunication network 202 to enable and / or provide network access, such as wireless network access, and / or to perform other functions, such as administration in the telecommunication network 202.

[0059] In the depicted example, the core network 206 connects the network nodes 210 to one or more hosts, such as host 216. These connections may be direct or indirect via one or more intermediary networks or devices. In other examples, network nodes may be directly coupled to hosts. The core network 206 includes one more core network nodes (e.g., core network node 208) that are structured with hardware and software components. Features of these components may be substantially similar to those described with respect to the UEs, network nodes, and / or hosts, such that the descriptions thereof are generally applicable to the corresponding components of the core network node 208. Example core network nodes include functions of one or more of a MobileSwitching Center (MSC), Mobility Management Entity (MME), Home Subscriber Server (HSS), Access and Mobility Management Function (AMF), Session Management Function (SMF), Authentication Server Function (AUSF), Subscription Identifier De-Concealing Function (SIDF), Unified Data Management (UDM), Security Edge Protection Proxy (SEPP), Network Exposure Function (NEF), and / or a User Plane Function (UPF).

[0060] The host 216 may be under the ownership or control of a service provider other than an operator or provider of the access network 204 and / or the telecommunication network 202, and may be operated by the service provider or on behalf of the service provider. The host 216 may host a variety of applications to provide one or more service. Examples of such applications include live and pre-recorded audio / video content, data collection services such as retrieving and compiling data on various ambient conditions detected by a plurality of UEs, analytics functionality, social media, functions for controlling or otherwise interacting with remote devices, functions for an alarm and surveillance center, or any other such function performed by a server.

[0061] As a whole, the communication system 200 of Figure 2 enables connectivity between the UEs, network nodes, and hosts. In that sense, the communication system 200 may be configured to operate according to predefined rules or procedures, such as specific standards that include, but are not limited to: Global System for Mobile Communications (GSM); Universal Mobile Telecommunications System (UMTS); Long Term Evolution (LTE), and / or other suitable Second, Third, Fourth, or Fifth Generation (2G, 3G, 4G, or 5G) standards, or any applicable future generation standard (e.g., Sixth Generation (6G)); Wireless Local Area Network (WLAN) standards, such as the Institute of Electrical and Electronics Engineers (IEEE) 802.11 standards (WiFi); and / or any other appropriate wireless communication standard, such as the Worldwide Interoperability for Microwave Access (WiMax), Bluetooth, Z-Wave, Near Field Communication (NFC) ZigBee, LiFi, and / or any Low Power Wide Area Network (LPWAN) standards such as LoRa and Sigfox.

[0062] In some examples, the telecommunication network 202 is a cellular network that implements 3GPP standardized features. Accordingly, the telecommunication network 202 may support network slicing to provide different logical networks to different devices that are connected to the telecommunication network 202. For example, the telecommunication network 202 may provide Ultra Reliable Low Latency Communication (URLLC) services to some UEs, while providing enhanced Mobile Broadband (eMBB) services to other UEs, and / or massive Machine Type Communication (mMTC) / massive Internet of Things (loT) services to yet further UEs.

[0063] In some examples, the UEs 212 are configured to transmit and / or receive information without direct human interaction. For instance, a UE may be designed to transmit information to the access network 204 on a predetermined schedule, when triggered by an internal or external event, or in response to requests from the access network 204. Additionally, a UE may be configured for operating in single- or multi-Radio Access Technology (RAT) or multi-standard mode. For example, a UE may operate with any one or combination of WiFi, New Radio (NR), and LTE, i.e., being configured for Multi-Radio Dual Connectivity (MR-DC), such as Evolved UMTS Terrestrial RAN (E-UTRAN) NR - Dual Connectivity (EN-DC).

[0064] In the example, a hub 214 communicates with the access network 204 to facilitate indirect communication between one or more UEs (e.g., UE 212C and / or 212D) and network nodes (e.g., network node 210B). In some examples, the hub 214 may be a controller, router, content source and analytics, or any of the other communication devices described herein regarding UEs. For example, the hub 214 may be a broadband router enabling access to the core network 206 for the UEs. As another example, the hub 214 may be a controller that sends commands or instructions to one or more actuators in the UEs. Commands or instructions may be received from the UEs, network nodes 210, or by executable code, script, process, or other instructions in the hub 214. As another example, the hub 214 may be a data collector that acts as temporary storage for UE data and, in some embodiments, may perform analysis or other processing of the data. As another example, the hub 214 may be a content source. For example, for a UE that is a Virtual Reality (VR) headset, display, loudspeaker or other media delivery device, the hub 214 may retrieve VR assets, video, audio, or other media or data related to sensory information via a network node, which the hub 214 then provides to the UE either directly, after performing local processing, and / or after adding additional local content. In still another example, the hub 214 acts as a proxy server or orchestrator for the UEs, in particular if one or more of the UEs are low energy loT devices.

[0065] The hub 214 may have a constant / persistent or intermittent connection to the network node 210B. The hub 214 may also allow for a different communication scheme and / or schedule between the hub 214 and UEs (e.g., UE 212C and / or 212D), and between the hub 214 and the core network 206. In other examples, the hub 214 is connected to the core network 206 and / or one or more UEs via a wired connection. Moreover, the hub 214 may be configured to connect to a Machine-to-Machine (M2M) service provider over the access network 204 and / or to another UE over a direct connection. In some scenarios, UEs may establish a wireless connection with the network nodes 210 while still connected via the hub 214 via a wired or wireless connection. In some embodiments, the hub 214 may be a dedicated hub - that is, a hub whose primary function is to route communications to / from the UEs from / to the network node 210B. In otherembodiments, the hub 214 may be a non-dedicated hub - that is, a device which is capable of operating to route communications between the UEs and the network node 210B, but which is additionally capable of operating as a communication start and / or end point for certain data channels.

[0066] Systems and methods for beam selection in Random Access Channel (RACH)-less Conditional Ll / L2-Triggered Mobility (CLTM) execution are provided. In some embodiments, a method at a User Equipment (UE) for performing beam selection during a CLTM execution procedure (which may be considered as an LTM Cell Switch upon fulfillment of an LTM execution condition) based on one or more criteria / rules is provided.

[0067] The current disclosure mentions Conditional LTM (CLTM), which may be seen as a type of conditional reconfiguration, in which execution conditions are associated to the evaluation of conditions associated to lower layer measurements e.g., Layer 1 (LI) RSRP, and / or SS-RSRP, based on SSB(s) and / or CSLRSs of a serving cell and / or of an LTM candidate cell (which may also be called a CLTM candidate cell). A lower layer measurement is this context may be defined as a measurement which is reported to support lower layer procedures, such as beam management, TCI state activation(s) / deactivations, early timing advance (TA) acquisition, link adaptation, etc. Lower layers measurements are not filtered according to Layer 3 (L3) parameters.

[0068] In this context, a CLTM relies on the UE evaluating an execution condition (or conditional LTM execution condition, or LTM execution condition, or triggering condition) or a combination of multiple executing conditions, that is / are evaluated, and when fulfilled, results in that the UE executes LTM Cell Switch (sometimes known as executing the condition) or conditional LTM execution; As part of that CLTM execution, the UE applies a message (e.g., RRC Reconfiguration including the LTM candidate cell configuration), parts of a message or at least one Information Element (IE), or performing a serving cell switch or change. Known existing examples of conditional reconfiguration are Conditional Handover (CHO), Conditional PSCell Change (CPC) and Conditional PSCell Addition (CPA). According to some embodiments of the current disclosure, upon fulfillment of the execution conditions(s) the UE performs an LTM Cell Switch

[0069] The current disclosure refers to an LTM candidate cell for conditional LTM, which may be called a conditional LTM candidate cell or CLTM candidate cell, or, simply candidate cell or LTM Candidate cell; or L1 / L2 inter-cell mobility candidate cell or target candidate cell or simply target cell for L1 / L2 inter-cell mobility to refer to a cell the UE is configured with when configured with conditional L1 / L2 inter-cell mobility; which is a cell the UE moves to or switches to in the execution of a conditional L1 / L2 inter-cell mobility procedure upon fulfillment of theassociated execution condition. These cells may also be called candidate cells, candidates, mobility candidates, non-serving cells, additional cells, deactivated cells, etc.

[0070] Figure 3 illustrates a method performed by a UE, according to some embodiments of the present disclosure. In some embodiments, the UE is configured (step 300) with at least one CLTM candidate cell, each of the at least one CLTM candidate cell having an associated CLTM Candidate cell configuration, and / or an associated LTM execution condition. The UE evaluates (step 302) the CLTM execution condition. In response to the CLTM execution condition being fulfilled, the UE selects (step 304) a CLTM candidate cell for which the CLTM execution condition has been fulfilled and applies (step 306) the CLTM candidate cell configuration of the selected CLTM candidate cell. For the selected CLTM candidate cell, the UE determines (step 308) to perform a RACH-less CLTM execution and / or selects a beam of the selected CLTM candidate cell based on one or more criteria / rules. The UE performs (step 310) beam selection during a CLTM execution procedure based on one or more criteria / rules.

[0071] Figure 4 illustrates a method performed by a network node, according to some embodiments of the present disclosure. In some embodiments, the network node configures (step 400) a UE with at least one CLTM candidate cell, each of the at least one CLTM candidate cell having an associated CLTM Candidate cell configuration, and / or an associated LTM execution condition. In response to the CLTM execution condition being fulfilled, a UE selects (step 402) a CLTM candidate cell for which the CLTM execution condition has been fulfilled and the UE applies (step 404) the CLTM candidate cell configuration of the selected CLTM candidate cell. For the selected CLTM candidate cell, the network node receives (step 406) a RACH-less CLTM execution and / or selection of a beam of the selected CLTM candidate cell based on one or more criteria / rules. The network node receives (step 408) a beam selection during a CLTM execution procedure based on one or more criteria / rules.

[0072] In some embodiments, the UE receives an LTM candidate cell configuration for conditional LTM, for an LTM candidate cell. The LTM candidate cell configuration may be received in the form of an RRC Reconfiguration message (e.g., RRCReconfiguration) which the UE stores and applies upon fulfillment of the conditional LTM execution condition associated to that LTM candidate cell. The LTM candidate cell configuration contains parameters the UE uses to operate in the associated LTM candidate cell when the UE moves to it in an LTM Cell switch. The LTM candidate cell configuration may be applied on top of the UE’s current configuration and / or on top of a reference configuration (also received by the UE e.g., as part of a conditional LTM configuration).

[0073] In the method the UE receives a conditional LTM execution condition. That may correspond to the UE receiving an indication of a conditional LTM execution condition and / or one or more parameters for configuring a conditional LTM execution condition e.g., event identifier, offset(s), threshold(s), reference signal (RS) type, trigger quantity, time to trigger, etc.

[0074] An LTM candidate cell may also be an LTM candidate cell in a 5G Radio access technology, such as NR, or a 6G Radio Access Technology.

[0075] Also, in the different embodiments, the co-called “beam” or RS of an LTM candidate cell comprises an SSB and / or an RS transmitted in a beam or spatial direction, and / or a Mobility Reference Signal (MRS), a Channel State Information - RS (CSI-RS), or a RS defined for a 6G radio interface. The term “beam” may also be used to express a spatial direction in which a Reference Signal (e.g., SSB) associated to an index (e.g., SSB index, or CSLRS index) is being transmitted, so that a beam measurement may correspond to a measurement on an RS transmitted in that beam e.g., an SSB measurement. In that sense, the steps for beam selection may corresponds to steps for selecting a Reference signal (RS) e.g., SSB, or SSB identifier, or beam identifier, or MRS, or CSLRS, etc. The steps may comprising further selecting one or more parameters associated to the selected beam (or RS).

[0076] In some embodiments disclosed herein, a beam (or RS) may be associated to a TCI e.g., by the RS (e.g., SSB) being configured as QCL source of a TCI state configuration. So, the term ‘beam’ and ‘RS’ (e.g., SSB) may be interchangeably used. For example, when the UE selects a beam, the UE selects an SSB.

[0077] An activated TCI state of an LTM candidate cell may also be called a pre-activated TCI state of the LTM candidate cell. The reason is that the UE receives the command to activate the LTM candidate cell before it receives the command to perform an LTM Cell Switch or, in the scenario of Conditional LTM, before the UE fulfills the LTM execution condition(s) and / or before the LTM Cell Switch execution.

[0078] According to the method when the UE receives a command to pre-activate (or activate) a TCI state of an LTM candidate cell, it may be said that the UE would be performing one or more DL synchronization actions (also called DL pre-synchronization, pre-synchronization, pre-sync, early DL synchronization) with an LTM candidate cell, comprising the UE detecting and / or measuring at least one synchronization signal of the LTM candidate cell, such as an Synchronization Signal Block (SSB), e.g., an SSB of the LTM candidate cell associated to an SSB index and / or identifier and transmitted in a spatial direction (beam), and / or a Channel State Information - Reference Signal (CSI-RS) and / or a Tracking Reference Signal (TRS) and / or a Primary Sync Signal (PSS) and / or a Secondary Sync Signal (SSS); in this context, measuringcomprises determining a measurement quantity value such as a Synchronization Signal based Reference Signal Received Power (SS-RSRP) and / or Synchronization Signal based Reference Signal Received Quality (SS-RSRQ) and / or Synchronization Signal based Signal to Noise and Interference Ratio (SS-SINR).

[0079] The UE performing DL synchronization with an LTM candidate cell comprises the UE performing fine time tracking and acquiring full timing information of the LTM candidate cell. Timing acquisition comprises obtaining the time boundaries of time units of a given LTM candidate cell such as time slot, OFDM symbol, subframe, radio frame. Timing acquisition comprises synchronizing a clock with the boundaries of time units of a given LTM candidate cell such as time slot, OFDM symbol, subframe, radio frame. The acquired fine timing is used as reference point for PRACH transmission and UE uplink transmissions.

[0080] The current disclosure refers to a RACH-less LTM execution procedure, which is an LTM execution (for LTM or CLTM) in which the UE does not transmit a Physical Random- Access Channel (PRACH) preamble to the LTM candidate cell as its first UL message. For the selected CLTM candidate cell, the UE can perform a RACH-less CLTM execution (e.g., when a previously acquired TA value is valid). However, the UE may be prepared to perform RACH-less but when the TA value becomes invalid the UE may perform RACH-based CLTM execution.

[0081] The current disclosure refers to the trigger condition in which a measurement is an offset better than another measurement, which may correspond to the measurement being an offset higher or above the other measurement.

[0082] Some embodiments describe an LTM Cell Switch procedure (which may also be called an execution of the Conditional LTM procedure) which the UE performs in response to the fulfillment of the LTM execution condition. In that procedure the UE applies (or switches to) the configuration of the LTM candidate cell which is to become the new PCell (i.e., a target cell in the mobility), selects a beam (e.g., an SSB, CSLRS or other RS) of that cell, and performs either random access or a RACH-less procedure, to then transmit a complete message (e.g., an RRC Reconfiguration Complete message).

[0083] In some embodiments, a method at a User Equipment (UE) for performing RACH-lessConditional LTM execution (or LTM Cell Switch upon fulfillment of an LTM execution condition). The UE is configured with at least one LTM candidate cell, with an LTM Candidate cell configuration, and an associated LTM execution condition e.g., measurement of the LTM candidate cell becomes offset better than a measurement of the serving cell. In some conditions, even if this is for the UE to perform RACH-less, when the UE is not able to perform RACH-less, beam selection may still be performed for a RACH-based solution.

[0084] When the CLTM execution condition is fulfilled, the UE selects an LTM candidate cell for which the LTM execution condition has been fulfilled and applies the LTM candidate cell configuration associated. For the selected LTM candidate cell, the UE determines that it needs to perform a RACH-less CLTM execution.

[0085] In one option, the UE determines to perform RACH-less CLTM execution when a previously provided Timing Advanced (TA) value is valid (e.g., a Time Alignment timer is running); and, when the UE determines that the TA value is valid (e.g., Time Alignment timer is running).

[0086] When the UE selects a CLTM candidate cell, to perform RACH-less CLTM execution, the UE selects a beam (in LTM cell Switch, that is provided in the MAC CE) based on one or more of the following rules / criteria. And, when there are multiple beams (SSBs) of the selected LTM candidate cell for which a first rule is fulfilled (denoted triggered beam(s)), the UE further selects one of the triggered beams (SSBs) of the CLTM candidate cell based on a further rule / criteria (a second rule). In other words, in one option, the UE selects a beam based on a combination of one or more of the rules / criteria.

[0087] Some of the rules / criteria based on which the UE may select a beam (e.g., SSB) or a selected CLTM candidate cell for RACH-less CLTM execution are detailed below.

[0088] Based on the availability of a valid UL grant

[0089] In other words, when there are multiple beams (e.g., SSBs) in the selected CLTM candidate cell, the UE selects the one for which an UL grant on an L physical channel (e.g., PUSCH) has been received at the UE. The benefit is that the UE would transmit in the UL of the CLTM candidate cell (e.g., the RRC Reconfiguration complete message) much faster, since the UE would not need first send a SR (e.g., on PUCCH), monitor a DL control channel (e.g., PDCCH) and only then obtain an UL grant for transmission of UL in an UL physical channel (e.g., PUSCH). Instead, the UE selects a beam (e.g., an SSB of the CLTM candidate cell) with an associated UL grant and directly transmits the RRC Reconfiguration complete message.

[0090] This UL grant may be called a pre-configured UL grant, and be associated to at least a beam, and / or a TCI state and / or a RS and / or a sync signal of the CLTM candidate cell which is selected for RACH-less CLTM execution.

[0091] When there are multiple beams (e.g., multiple SSBs of the CLTM candidate cell) for which UL grant(s) are configured (or pre-configured), the UE selects one of these beams (e.g., one of these SSBs) based on a further rule / criterion, e.g.:

[0092] In some embodiments, UE further selects a beam (e.g., SSB) of the selected LTM candidate cell associated to a pre-activated TCI state. In other words, the combined rule is as a follows: “select a beam (SSB) for which an UL grant is configured AND, if there are multiple, select the beam (SSB) associated to a pre-activated TCI state, if any”. The benefit is also on the network side, which is monitoring the beam(s) for which TCI state(s) have been pre-activated.

[0093] In some embodiments, UE further selects a beam (e.g., SSB) for which the UL grant is associated to the first UL resource available in the LTM candidate cell (i.e., pre-configured) after the moment the UE determined the fulfillment of the execution condition. The benefit is that the UE transmits the RRC Reconfiguration complete as fast as possible when multiple beams have a pre-configured UL grant.

[0094] In some embodiments, UE further selects a beam (e.g., SSB) for which a measurement quantity (e.g., RSRP, RSRQ or SINR) is the highest among other beams with at least one available UL grant. The benefit is that the UE transmits the RRC Reconfiguration complete in the most robust beam, and network is less likely to trigger a beam switching shortly after the LTM Cell Switch.

[0095] In some embodiments, UE further selects a beam (e.g., SSB) for which a measurement quantity (e.g., RSRP, RSRQ, SINR) is above a threshold or a pre-defined value. The benefit is that the UE transmits the RRC Reconfiguration complete in a robust beam, and the UE is less likely to have a beam failure detection, and / or radio link failure.

[0096] Based on the availability of SR Configuration

[0097] In other words, when there are multiple beams (e.g., SSBs) in the selected LTM candidate cell, the UE selects the one for which the UE has received SR configuration along with the pre-configured PUCCH resources (for SR transmission in the CLTM candidate cell). The benefit is that the UE would not be required to perform random-access to the LTM candidate cell upon the fulfillment of execution conditions. Instead, the UE selects a beam (e.g., SSB) with available SR configuration and uses the corresponding PUCCH resources for requesting an UL grant. The UE then monitors the PDCCH to receive the UL grant for sending RRC Reconfiguration complete message after CLTM execution.

[0098] This SR configuration can be associated to at least a beam, and / or a TCI state and / or a RS and / or a sync signal of the CLTM candidate cell which is selected for RACH-less CLTM execution.

[0099] When there are multiple beams (SSBs) for which SR configuration is provided, the UE selects one of them based on a further rule / criterion, e.g.:

[0100] UE further selects a beam (SSB) of the selected LTM candidate cell associated to a pre-activated TCI state. In other words, the combined rule is described as: “select a beam (SSB) for which SR configuration is provided AND, if there are multiple, select the beam (SSB) associated to a pre-activated TCI state, if any”. The benefit is also on the network side, which is monitoring the beam(s) for which TCI state(s) have been pre-activated, to receive the SR sent by the UE.

[0101] UE further selects a beam for which the SR configuration points to the first available PUCCH resource in the LTM candidate cell after the moment the UE determined the fulfillment of the execution condition. The benefit is that the UE can send the SR for obtaining UL grant in the first PUCCH resource available as fast as possible.

[0102] UE further selects a beam (SSB) for which a measurement quantity (e.g., RSRP, RSRQ or SINR) is the highest among other beams. The benefit is that the UE transmits the SR after cell switch in the most robust beam, and the network is more likely to receive the SR transmitted and less likely to trigger a beam switching shortly after the LTM Cell Switch.

[0103] UE further selects a beam (SSB) for which a measurement quantity (e.g., RSRP, RSRQ, SINR) is above a threshold or a pre-defined value. The benefit is that the UE transmits the SR after cell switch in a robust beam, and the UE is less likely to have a beam failure detection, and / or radio link failure.

[0104] Selection among the beam(s) with SR Configuration and the beam(s) with preconfigured UL grant: In other words, when there is one or more beam(s) for which the UE has received the SR configuration with the corresponding PUCCH resources and also one or more beam(s) for which there is available UL grant on PUSCH resources, the UE selects the beam with valid UL grant. The benefit is that the UE can use the UL grant directly to send RRC Reconfiguration complete message on the UL grant faster, and is not required to send SR over PUCCH to obtain the UL grant.

[0105] Based on a threshold or pre-defined value I interval for a measurement quantity e.g., RSRP threshold or value / interval, RSRQ threshold or value / interval, SINR threshold or value / interval: In other words, when there are multiple beams (e.g., SSBs) in the selected LTM candidate cell, the UE selects the beam(s) with a measurement quantity above a threshold.

[0106] For example, the UE selects a beam (e.g., SSB, MRS, CSLRS, or other RS or sync signal) with RSRP above an RSRP threshold or within an RSRP interval or above an RSRP value or interval. For example, the UE selects a beam (e.g., SSB, MRS, CSLRS, or other RS or sync signal) with RSRQ above an RSRQ threshold or within an RSRQ interval or above an RSRQ valueor interval. For example, the UE selects a beam (e.g., SSB, MRS, CSI-RS, or other RS or sync signal) with SINR above an SINR threshold or within an SINR interval or above an SINR value or interval. The benefit is that the UE transmits the RRC Reconfiguration complete in the most robust beam, and network is less likely to trigger a beam switching shortly after the LTM Cell Switch.

[0107] When there are multiple beams (SSBs) for which the measurement quantity is above the threshold, the UE further selects one of the beams (SSBs) based on a further rule, e.g.:

[0108] UE further selects a beam (e.g., SSB) of the selected LTM candidate cell associated to a pre-activated TCI state. In other words, the combined rule is as a follows: “select a beam (SSB) for which measurement quantity (e.g., RSRP) is above the threshold (RSRP threshold) AND, if there are multiple, select the beam (SSB) associated to a pre-activated TCI state, if any”. The benefit of the combine rule is that the UE selects, among the robust beams (whose RSRP is good enough), the one for which the UE is DL synchronized i.e., is has a pre-activated TCI state. The benefit is also on the network side, which is monitoring the beam(s) for which TCI state(s) have been pre-activated.

[0109] UE further selects a beam for which an UL grant is available in the LTM candidate cell. In other words, the combined rule is as a follows: “select a beam (SSB) for which measurement quantity (e.g., RSRP) is above the threshold (RSRP threshold) AND, if there are multiple, select the beam (SSB) for which an UL grant is available. The benefit is that the UE transmits the RRC Reconfiguration complete faster, compared to a beam for which the UE would first need to send an SR over PUCCH.

[0110] UE further selects a beam for which the UL grant is associated to the first UL resource available in the LTM candidate cell, after the moment the UE determined the fulfillment of the execution condition (UE implementation). In other words, the combined rule is as a follows: “select a beam (SSB) for which measurement quantity (e.g., RSRP) is above the threshold (RSRP threshold) AND, if there are multiple, select the beam (SSB) for which the UL grant is associated to the first UL resource available in the LTM candidate cell”. The benefit is that the UE transmits the RRC Reconfiguration complete as fast as possible, even among other beams for which an UL grant has been configured.

[0111] UE further selects a beam for which SR configuration is available in the LTM candidate cell. The combined rule is stated as follows: “select a beam (SSB) for which measurement quantity (e.g., RSRP) is above the pre-defined threshold (i.e., RSRP threshold) AND, if there are multiple such beams, select the beam (SSB) for which the UE has obtained the SR configuration and the configured PUCCH resources”. The benefit is that the UE does not haveto perform random- access, and the UE can directly send SR on the available PUCCH resource over a robust beam to request the UL grant for sending RRC Reconfiguration complete.

[0112] UE further selects a beam for which the SR configuration points to the first available PUCCH resource in the LTM candidate cell. The combined rule is stated as: “select a beam (SSB) for which measurement quantity (e.g., RSRP) is above the pre-defined threshold (i.e., RSRP threshold) AND, if there are multiple such beams, select the beam (SSB) for which the SR configuration points to the first available PUCCH resource in the LTM candidate cell.” The benefit is that the UE can send the SR for obtaining UL grant in the first PUCCH resource available as fast as possible even among other beams for which the SR configuration has been provided, over a robust beam.

[0113] When there is at least one beam with SR configuration available and at least one beam with pre-allocated UL grant. In this case, the UE always selects the beam with UL grant available. The combined rule for selection can be stated as: “select a beam (SSB) for which measurement quantity (e.g., RSRP) is above the threshold (RSRP threshold) AND, if there is at least one beam with pre-allocated UL grant and another beam with SR configuration available, select the beam (SSB) for which the UL grant is provided. The benefit is that the UE transmits the RRC Reconfiguration complete faster, compared to a beam for which the UE would first need to send an SR over PUCCH.

[0114] UE further selects a beam (SSB) for which measurement quantity (e.g., RSRP) is the highest. In other words, the combined rule is as a follows: “select a beam (SSB) for which measurement quantity (e.g., RSRP) is above the threshold (RSRP threshold) AND, if there are multiple, select the beam (SSB) for which the measurement quantity (RSRP) is the highest”. The benefit is that the UE transmits the RRC Reconfiguration complete not only to a robust beam, but to the most robust beam, and network is less likely to trigger a beam switching shortly after the LTM Cell Switch.

[0115] Based on an availability of a pre-activated TCI state

[0116] In other words, when there are multiple beams (e.g., SSBs) in the selected LTM candidate cell, the UE selects a beam (e.g., SSB) of the selected LTM candidate cell associated to a pre-activated TCI state.

[0117] Being associated in this context means, for example, that the beam (SSB) is configured as Quasi-Co-Location (QCL) source of the TCI state which has been pre- activated. In some embodiments, the selected beam is QCLed with the SSB and the TCI state.

[0118] A TCI state of an LTM candidate cell is pre-activated when the UE receives a command from a serving cell (e.g., a Candidate Cell TCI States Activation / Deactivation MAC CE) while configured with Conditional LTM, before the fulfillment of the LTM execution condition for that LTM candidate cell. At the network side, the S-DU transmits a command to activate a TCI state of an CLTM candidate cell and becomes aware of which beam the UE may select and may transmit an SR and / or pre-configured UL grant, which benefits the NW in becoming aware of the beam it needs to monitor during a potential CLTM execution.

[0119] The benefit of the rule is that the UE selects the beam (SSB) for which the UE is DL synchronized i.e., has a pre-activated TCI state. The benefit is also on the network side, which is monitoring the beam(s) for which TCI state(s) have been pre-activated.

[0120] When there are multiple beams (SSBs) of the selected CLTM candidate cell for which associated pre-activated TCI state(s) are available, the UE further selects one of the beams (SSBs) based on a further rule, e.g.:

[0121] UE further selects a beam for which an UL grant is available in the LTM candidate cell. In other words, the combined rule is as a follows: “select a beam (SSB) for which a TCI state is pre-activated AND, if there are multiple, select the beam (SSB) for which an UL grant is available”. The benefit is that the UE transmits the RRC Reconfiguration complete faster, compared to a beam for which the UE would first need to send an SR over PUCCH, for a beam for which TCI is pre-activated i.e., for which the UE is DL synchronized.

[0122] UE further selects a beam for which the UL grant is associated to the first UL resource available in the LTM candidate cell, after the moment the UE determined the fulfillment of the execution condition (UE implementation). In other words, the combined rule is as a follows: “select a beam (SSB) for which a TCI state is pre-activated AND, if there are multiple, select the beam (SSB) for which the UL grant is associated to the first UL resource available in the LTM candidate cell”. The benefit is that the UE transmits the RRC Reconfiguration complete as fast as possible, even among other beams for which an UL grant has been configured, and among the beams for which a TCI state is pre-activated i.e., for which the UE is DL synchronized.

[0123] UE further selects a beam for which SR configuration is available in the LTM candidate cell. The combined rule is stated as follows: “select a beam (SSB) for which TCI state is pre-activated AND, if there are multiple such beams, select the beam (SSB) for which the UE has obtained the SR configuration and the configured PUCCH resources”. The benefit is that the UE does not have to perform random- access, and the UE can directly send SR on the available PUCCH resource over a beam with pre-activated TCI state to request the UL grant for sending RRC Reconfiguration complete.

[0124] UE further selects a beam for which the SR configuration points to the first available PUCCH resource in the LTM candidate cell. The combined rule is stated as: “select a beam (SSB) for which TCI state is pre-activated AND, if there are multiple such beams, select the beam (SSB) for which the SR configuration points to the first available PUCCH resource in the LTM candidate cell.” The benefit is that the UE can send the SR for obtaining UL grant in the first PUCCH resource available as fast as possible even among other beams for which the SR configuration has been provided, over a beam with activated TCI state.

[0125] When there is at least one beam with SR configuration available and at least one beam with pre-allocated UL grant. In this case, the UE always selects the beam with UL grant available. The combined rule for selection can be stated as: “select a beam (SSB) for which TCI state is preactivated AND, if there is at least one beam with pre-allocated UL grant and another beam with SR configuration available, select the beam (SSB) for which the UL grant is provided. The benefit is that the UE transmits the RRC Reconfiguration complete faster, compared to a beam for which the UE would first need to send an SR over PUCCH.

[0126] UE further selects a beam (SSB) for which a measurement quantity is above a threshold and / or a measurement quantity value or within a measurement quantity interval. In other words, the combined rule is as a follows: “select a beam (SSB) for which a TCI state is preactivated AND, if there are multiple, select the beam (SSB) for which a measurement quantity (RSRP) is above a threshold. The benefit is that the UE transmits the RRC Reconfiguration complete in a robust beam, and the UE is less likely to trigger a beam failure detection.

[0127] UE further selects a beam (SSB) for which measurement quantity (e.g., RSRP) is the highest. In other words, the combined rule is as a follows: “select a beam (SSB) for which a TCI state is pre-activated AND, if there are multiple, select the beam (SSB) for which the measurement quantity (RSRP) is the highest”. The benefit is that the UE transmits the RRC Reconfiguration complete not only to a robust beam, but to the most robust beam, and network is less likely to trigger a beam switching shortly after the LTM Cell Switch.

[0128] Based on the Downlink (DL) synchronization ‘status’ associated to a beam of the selected CLTM candidate cell

[0129] In other words, when there are multiple beams (e.g., SSBs) in the selected LTM candidate cell, the UE selects a beam (SSB) of the selected LTM candidate cell for which the UE is DL synchronized.

[0130] In one option, the UE DL synchronizes with a beam of the selected CLTM candidate cell before the fulfillment of the CLTM execution condition(s), so that this may be called a DL pre-synchronization, or Early DL sync.

[0131] In other words, the UE has performed for the selected beam and / or for the selected CLTM candidate cell one or more of the following steps: a. detected and / or measured at least one synchronization signal of the LTM candidate cell, such as an SSB of the LTM candidate cell associated to an SSB index and / or identifier and transmitted in a spatial direction (beam), and / or a CSLRS and / or a TRS and / or a PSS and / or a SSS; b. performed fine time tracking and acquired full timing information of the LTM candidate cell (and beam). c. obtained the time boundaries of time units of a given LTM candidate cell (and beam) such as time slot, OFDM symbol, subframe, radio frame. d. synchronized a clock with the boundaries of time units of a given LTM candidate cell (and beam) such as time slot, OFDM symbol, subframe, radio frame.

[0132] When there are multiple beams (SSBs) of the selected CLTM candidate cell for which the UE has performed DL sync (or pre-sync), the UE further selects one of the beams (SSBs) based on a further rule, e.g.:

[0133] UE further selects a beam for which an UL grant is available in the LTM candidate cell. In other words, the combined rule is as a follows: “select a beam (SSB) for which the UE has performed DL sync AND, if there are multiple, select the beam (SSB) for which an UL grant is available”. The benefit is that the UE transmits the RRC Reconfiguration complete faster, compared to a beam for which the UE would first need to send an SR over PUCCH, for a beam for which the UE has performed DL sync.

[0134] UE further selects a beam for which the UL grant is associated to the first UL resource available in the LTM candidate cell, after the moment the UE determined the fulfillment of the execution condition (UE implementation). In other words, the combined rule is as a follows: “select a beam (SSB) for which the UE has performed DL sync AND, if there are multiple, select the beam (SSB) for which the UL grant is associated to the first UL resource available in the LTM candidate cell”. The benefit is that the UE transmits the RRC Reconfiguration complete as fast as possible, even among other beams for which an UL grant has been configured, and among the beams for which the UE has DL sync.

[0135] UE further selects a beam for which SR configuration is available in the LTM candidate cell. The combined rule is stated as follows: “select a beam (SSB) for which UE has performed DL Sync. AND, if there are multiple such beams, select the beam (SSB) for which the UE has obtained the SR configuration and the configured PUCCH resources”. The benefit is that the UE does not have to perform random-access, and the UE can directly send SR on the available PUCCH resource over a beam for which the UE has performed DL Sync., to request the UL grant.

[0136] UE further selects a beam for which the SR configuration points to the first available PUCCH resource in the LTM candidate cell. The combined rule is stated as: “select a beam (SSB) for which UE has performed DL Sync. AND, if there are multiple such beams, select the beam (SSB) for which the SR configuration points to the first available PUCCH resource in the LTM candidate cell.” The benefit is that the UE can send the SR for obtaining UL grant in the first PUCCH resource available as fast as possible even among other beams for which the SR configuration has been provided, over a beam for which the UE has performed DL Sync.

[0137] When there is at least one beam with SR configuration available and at least one beam with pre-allocated UL grant. In this case, the UE always selects the beam with UL grant available. The combined rule for selection can be stated as : “select a beam (SSB) for which UE has performed DL Sync. And, if there is at least one beam with pre-allocated UL grant and another beam with SR configuration available, select the beam (SSB) for which the UL grant is provided. The benefit is that the UE transmits the RRC Reconfiguration complete faster, compared to a beam for which the UE would first need to send an SR over PUCCH.

[0138] UE further selects a beam (SSB) for which a measurement quantity is above a threshold and / or a measurement quantity value or within a measurement quantity interval. In other words, the combined rule is as a follows: “select a beam (SSB) for which the UE has performed DL sync AND, if there are multiple, select the beam (SSB) for which a measurement quantity (RSRP) is above a threshold. The benefit is that the UE transmits the RRC Reconfiguration complete in a robust beam, and the UE is less likely to trigger a beam failure detection.

[0139] UE further selects a beam (SSB) for which measurement quantity (e.g., RSRP) is the highest. In other words, the combined rule is as a follows: “select a beam (SSB) for which the UE has performed DL sync AND, if there are multiple, select the beam (SSB) for which the measurement quantity (RSRP) is the highest”. The benefit is that the UE transmits the RRC Reconfiguration complete not only to a robust beam, but to the most robust beam, and network is less likely to trigger a beam switching shortly after the LTM Cell Switch.

[0140] Based on the Uplink (UL) synchronization ‘status’ associated to a beam of the selected CLTM candidate cell:

[0141] In other words, when there are multiple beams (e.g., SSBs) in the selected LTM candidate cell, the UE selects a beam (SSB) of the selected LTM candidate cell for which the UE is UL synchronized.

[0142] In one option, the UE UL synchronizes with a beam of the selected cell before the fulfillment of the CLTM execution condition(s), so that this may be called a UL presynchronization or Early UL sync.

[0143] In one option, the UE is UL synchronized to a beam (e.g., SSB) for which the UE has been configured with a TA acquisition procedure and for which the UE has further received a trigger (e.g., PDCCH order) for transmitting a Physical Random Access Channel (PRACH) preamble to the CLTM candidate cell, and to an indicated beam (e.g., indicated SSB in the PDCCH order), based on which the UE has selected a beam and a PRACH resource configuration for transmitting the PRACH preamble; that indicated beam may be considered the beam which the UE is UL sync with, and the beam which the UE further selects when the CLTM execution condition is fulfilled for that CLTM candidate cell.

[0144] When there are multiple beams (SSBs) of the selected CLTM candidate cell for which the UE has performed UL sync (or pre- sync, TA acquisition), the UE further selects one of the beams (SSBs) based on a further rule, e.g.:

[0145] UE further selects a beam for which the UE has also performed DL sync. In other words, the combined rule is as a follows: “select a beam (SSB) for which the UE has perform UL sync AND DL sync”. The benefit is that the UE transmits the RRC Reconfiguration complete faster, compared to a beam for which the UE would first need to send an SR over PUCCH, for a beam for which the UE has performed UL sync, but also would not require DL sync.

[0146] UE further selects a beam for which an UL grant is available in the LTM candidate cell. In other words, the combined rule is as a follows: “select a beam (SSB) for which the UE has perform UL sync AND, if there are multiple, select the beam (SSB) for which an UL grant is available”. The benefit is that the UE transmits the RRC Reconfiguration complete faster, compared to a beam for which the UE would first need to send an SR over PUCCH, for a beam for which the UE has performed UL sync.

[0147] UE further selects a beam for which the UL grant is associated to the first UL resource available in the LTM candidate cell, after the moment the UE determined the fulfillment of the execution condition (UE implementation). In other words, the combined rule is as a follows:“select a beam (SSB) for which the UE has perform UL sync AND, if there are multiple, select the beam (SSB) for which the UL grant is associated to the first UL resource available in the LTM candidate cell”. The benefit is that the UE transmits the RRC Reconfiguration complete as fast as possible, even among other beams for which an UL grant has been configured, and among the beams for which the UE has UL sync.

[0148] UE further selects a beam for which SR configuration is available in the LTM candidate cell. The combined rule is stated as follows: “select a beam (SSB) for which UE has performed UL Sync. AND, if there are multiple such beams, select the beam (SSB) for which the UE has obtained the SR configuration and the configured PUCCH resources”. The benefit is that the UE does not have to perform random-access, and the UE can directly send SR on the available PUCCH resource over a beam for which the UE has performed UL Sync., to request the UL grant.

[0149] UE further selects a beam for which the SR configuration points to the first available PUCCH resource in the LTM candidate cell. The combined rule is stated as: “select a beam (SSB) for which UE has performed UL Sync. AND, if there are multiple such beams, select the beam (SSB) for which the SR configuration points to the first available PUCCH resource in the LTM candidate cell.” The benefit is that the UE can send the SR for obtaining UL grant in the first PUCCH resource available as fast as possible even among other beams for which the SR configuration has been provided, over a beam for which the UE has performed UL Sync.

[0150] When there is at least one beam with SR configuration available and at least one beam with pre-allocated UL grant. In this case, the UE always selects the beam with UL grant available. The combined rule for selection can be stated as : “select a beam (SSB) for which UE has performed UL Sync. AND, if there is at least one beam with pre-allocated UL grant and another beam with SR configuration available, select the beam (SSB) for which the UL grant is provided. The benefit is that the UE transmits the RRC Reconfiguration complete faster, compared to a beam for which the UE would first need to send an SR over PUCCH.

[0151] UE further selects a beam (SSB) for which a measurement quantity is above a threshold and / or a measurement quantity value or within a measurement quantity interval. In other words, the combined rule is as a follows: “select a beam (SSB) for which the UE has perform UL sync AND, if there are multiple, select the beam (SSB) for which a measurement quantity (RSRP) is above a threshold. The benefit is that the UE transmits the RRC Reconfiguration complete in a robust beam, and the UE is less likely to trigger a beam failure detection.

[0152] UE further selects a beam (SSB) for which measurement quantity (e.g., RSRP) is the highest. In other words, the combined rule is as a follows: “select a beam (SSB) for which the UE has perform UL sync AND, if there are multiple, select the beam (SSB) for which the measurementquantity (RSRP) is the highest”. The benefit is that the UE transmits the RRC Reconfiguration complete not only to a robust beam, but to the most robust beam, and network is less likely to trigger a beam switching shortly after the LTM Cell Switch.

[0153] Based on the contention free random access dedicated configuration (e.g., CFRA) associated to a beam of the selected CLTM candidate cell

[0154] In other words, when there are multiple beams (e.g., SSBs) in the selected LTM candidate cell, the UE selects a beam (SSB) which is also associated to a contention free random access configuration associated to the selected LTM candidate cell.

[0155] In such a case, the dedicated random access configuration is different from the random access configuration used for the early UL synchronization procedure. This dedicated random access configuration is the random access configuration that is used by the UE to perform a contention free random access procedure (CFRA).

[0156] When there are multiple beams (SSBs) of the selected CLTM candidate cell which are mapped also to a contention free random access configuration, the UE further selects one of the beams (SSBs) based on a further rule, e.g.:

[0157] UE further selects a beam (SSB) of the selected LTM candidate cell associated to a pre-activated TCI state. In other words, the combined rule is as a follows: “select a beam (SSB) which is mapped to a contention free random access configuration AND, if there are multiple, select the beam (SSB) associated to a pre-activated TCI state, if any”. The benefit is also on the network side, which is monitoring the beam(s) for which TCI state(s) have been pre-activated.

[0158] UE further selects a beam for which the UL grant is associated to the first UL resource available in the LTM candidate cell (i.e., pre-configured) after the moment the UE determined the fulfillment of the execution condition. The benefit is that the UE transmits the RRC Reconfiguration complete as fast as possible when multiple beams have a pre-configured UL grant.

[0159] UE further selects a beam (SSB) for which a measurement quantity (e.g., RSRP, RSRQ or SINR) is the highest among other beams with at least one available UL grant. The benefit is that the UE transmits the RRC Reconfiguration complete in the most robust beam, and network is less likely to trigger a beam switching shortly after the LTM Cell Switch.

[0160] UE further selects a beam (SSB) for which a measurement quantity (e.g., RSRP, RSRQ, SINR) is above a threshold or a pre-defined value. The benefit is that the UE transmits the RRC Reconfiguration complete in a robust beam, and the UE is less likely to have a beam failure detection, and / or radio link failure.

[0161] In one option, the UE receives an indication of a rule / criteria to be used during beam selection of a beam of a selected LTM candidate cell for excitation. For example, the UE receives an indication (e.g., in the CLTM configuration) that it shall select a beam of a selected CLTM candidate cell based on the DL synchronization ‘status’ associated to a beam of the selected CLTM candidate cell, so that upon fulfillment of the CLTM execution condition the UE selects a CLTM candidate cell fulfilling the CLTM execution condition, and selects a beam of the CLTM candidate cell for which the UE is DL sync with it e.g., the TCI state is activated (pre-activated) for that beam.

[0162] In one option of the method, after having selected the beam of the selected CTLM candidate cell, the UE performs the execution of CLTM by transmitting a Scheduling Request (SR) e.g., over a Physical Uplink Control Channel (PUCCH) associated to the selected beam (e.g., a selected SSB, or selected RS, or selected CSLRS, or selected MRS, etc.) of the selected CLTM candidate cell. The UE may receive in response an UL grant over a DL control channel (PDCCH), and transmit UL information (e.g., LTM complete message) using that UL grant, over a Physical UL Shared Channel (PUSCH) of the CLTM candidate cell.

[0163] In one option of the method, after having selected the beam of the selected CTLM candidate cell, the UE performs the execution of CLTM by transmitting UL information (e.g., LTM complete message, or payload associated to the LTM complete message, like an RRC Reconfiguration Complete) using pre-configured UL grant over a Physical UL Shared Channel (PUSCH), wherein the pre-configured UL grant is associated with the selected beam of the selected CLTM candidate cell.

[0164] In one option of the method, after having selected the beam of the selected CTLM candidate cell, the UE performs the execution of CLTM by monitoring an UL grant over a DL control channel (e.g., PDCCH), wherein the DL control channel is associated to the selected beam.

[0165] In one option of the method, the CLTM execution condition is based on a beam (e.g., an SSB) measurement of a CLTM candidate cell and, the beam fulfilling the execution condition is denoted a triggered beam of a CLTM candidate cell. For example, a CLTM execution condition may be” a beam of a CLTM candidate cell is better (e.g., higher) than a threshold”. When at least one beam of a CLTM candidate cell fulfills the condition, the CLTM candidate cell is a triggered cell and when that cell is selected, the UE further selects one of the beams (e.g., one of the SSBs) of that CLTM candidate cell which are triggered beams. In other words, the UE further selects a triggered beam out of multiple triggered beams, from the selected triggered CLTM candidate cell. Further examples of CLTM execution conditions are provided herein. Additionally, some examples of CLTM execution condition(s) which may be specified are described. Upon thefulfillment of the CLTM execution condition(s) the UE initiated the RACH-less CLTM execution and, upon selecting a CLTM candidate cell, the UE initiates the beam selection, according to some embodiments.

[0166] In some embodiments, the CLTM execution condition may be one or more of the following: a. A measurement of a CLTM candidate cell becoming an offset better (e.g., offset higher, offset larger) than a measurement of a serving cell (e.g., of the PCell); b. A measurement of a CLTM candidate cell becoming higher than a threshold; c. A measurement of a CLTM candidate cell becoming better (e.g., higher) than a threshold AND a measurement of a serving cell becoming worse (e.g., lower) than a second threshold.

[0167] In some embodiments, the CLTM execution condition is based on at least an activated TCI state of a CLTM candidate cell.

[0168] In some embodiments, the CLTM execution condition (or simply called triggering condition) is defined as a first measurement associated to an LTM candidate cell becoming an offset better than a second measurement associated to a serving cell for which a TCI state is activated.

[0169] In some embodiments, the second measurement is performed on a beam and / or RS and / or an SSB and / or a CSLRS associated to the TCI state which is activated in the serving cell.

[0170] In some embodiments, the serving cell for which a TCI state is activated comprises a Special Cell (SpCell), such as a Primary Cell (PCell) of the Master Cell Group (MCG) or a Primary SCG Cell (PSCell) of a Secondary Cell Group (SCG).

[0171] In some embodiments, the serving cell for which a TCI state is activated comprises a Secondary Cell (SCell) of the MCG or a SCell of a SCG.

[0172] In some embodiments, before the UE evaluates the LTM execution condition, the UE is configured by the network with one or more parameters associated to the triggering condition. The one or more parameters associated to the triggering condition comprises one or more of: a triggering condition identifier (e.g., event ID), a Time To Trigger (TTT) value, a time-domain filtering configuration, a relative threshold and / or an offset associated to a trigger quantity, a trigger quantity (e.g., RSRP, RSRQ, SINR).

[0173] In some embodiments, the second measurement is performed on a beam and / or RS and / or an SSB and / or a CSLRS associated to a subset of TCI states of the serving cell which are configured to evaluate the triggering condition.

[0174] In some embodiments, the first measurement associated to an LTM Candidate cell comprises a measurement of a beam (or RS transmitted in a beam) of the LTM Candidate cell; and, the second measurement associated to the serving cell for which a TCI state is activated (and / or indicated) comprises a beam measurement associated to the serving cell.

[0175] The first measurement may be associated to an LTM Candidate cell and includes a measurement of a beam (or RS transmitted in a beam) of the LTM Candidate cell for which a TCI state is activated (and / or indicated and / or pre-activated). The first measurement may be associated to an LTM Candidate cell, including a measurement of a beam (or RS transmitted in a beam) of the LTM Candidate cell which is associated to a TCI state belonging to a subset of TCI states which are configured in order the UE to evaluate the triggering condition.

[0176] In some embodiments, the triggering condition may be defined as: a “best” beam (or RS) of the LTM candidate cell becoming an offset better than a “best” beam (or RS) of the serving cell.

[0177] In some embodiments, the triggering condition comprises: a “best” beam (or RS) of the LTM candidate cell becoming an offset better than a “best” beam (or RS) of the serving cell, wherein the best “beam” of the LTM candidate cell is associated to a pre-activated TCI state of the LTM candidate cell.

[0178] In some embodiments, the first measurement associated to an LTM Candidate cell comprises a cell level measurement of the LTM Candidate cell and the second measurement associated to the serving cell for which a TCI state is activated (and / or indicated) comprises a cell level measurement associated to the serving cell.

[0179] In some embodiments, the triggering condition comprises: the cell quality of an LTM candidate cell becomes an offset better than the cell quality of the serving cell, wherein the cell quality is based on at least one LTM related configuration.

[0180] In some embodiments, the first measurement is associated to an LTM candidate cell which has at least one TCI state activated (and / or indicated or and / or pre-activated).

[0181] In some embodiments, the first measurement is associated to an LTM candidate cell which has a subset of TCI states which are configured in order the UE to evaluate the triggering condition.

[0182] In some embodiments, the LTM candidate cell on which the first measurement is performed is an LTM candidate cell which has at least one TCI state activated (and / or indicated or and / or pre-activated).

[0183] In some embodiments, the LTM candidate cell on which the first measurement is performed is an LTM candidate cell which has a subset of TCI states which are configured in order the UE to evaluate the triggering condition.

[0184] In some embodiments, the first measurement is performed on a beam and / or RS and / or SSB and / or CSLRS and / or a Mobility Reference Signal (MRS) associated with an activated TCI state (pre-activated) of the LTM candidate cell.

[0185] In some embodiments, the first measurement is performed on a beam and / or RS and / or SSB and / or CSLRS configured as QCL source of an activated TCI state (pre-activated and / or indicated) of the LTM candidate cell.

[0186] In some embodiments, the first measurement is performed on a beam and / or RS and / or SSB and / or CSLRS and / or a Mobility Reference Signal (MRS) associated to a TCI state belonging to a subset of TCI states which are configured in order the UE to evaluate the triggering condition.

[0187] In some embodiments, before the UE evaluates and / or monitors the triggering condition (LTM execution condition), the UE receives a configuration of at least one TCI state of the LTM candidate cell in a first message (e.g., RRC Reconfiguration), and further receives in a second message (e.g., MAC CE for activating a candidate TCI state) an activation command to activate and / or to pre-activate the at least one TCI state of the LTM candidate cell. And, in response to further receiving in the second message the activation command to activate and / or to pre-activate the at least one TCI state of the LTM candidate cell, the UE evaluates the fulfillment of the triggering condition (LTM execution condition).

[0188] In some embodiments, the UE evaluates the fulfillment of the triggering condition (LTM execution condition) for any RS ID(s) and / or beam(s) and / or SSB ID(s) and / or CSLRS identifiers associated to TCI states of an LTM candidate cell which are not pre-activated, when there is no pre-activated TCI state of the LTM candidate cell.

[0189] In some embodiments, the LTM candidate cell on which the first measurement is associated is an LTM candidate cell which has a TCI state deactivated (e.g., the LTM candidate cell may have multiple TCI states, at least one activated, but at least one deactivated).

[0190] In some embodiments, the first measurement is associated to only LTM candidate cells on which TCI state(s) are activated.

[0191] In some embodiments, the TCI state which is pre-activated is associated to a QCL source configured as an SSB identifier, and / or a CSLRS resource identifier.

[0192] In some embodiments, the UE considers an LTM candidate cell to be used as input to the execution condition when the UE has a valid time alignment for that cell.

[0193] Figure 5 shows a UE 500 in accordance with some embodiments. As used herein, a UE refers to a device capable, configured, arranged, and / or operable to communicate wirelessly with network nodes and / or other UEs. Examples of a UE include, but are not limited to, a smart phone, mobile phone, cell phone, Voice over Internet Protocol (VoIP) phone, wireless local loop phone, desktop computer, Personal Digital Assistant (PDA), wireless camera, gaming console or device, music storage device, playback appliance, wearable terminal device, wireless endpoint, mobile station, tablet, laptop, Laptop Embedded Equipment (LEE), Laptop Mounted Equipment (LME), smart device, wireless Customer Premise Equipment (CPE), vehicle, vehicle-mounted or vehicle embedded / integrated wireless device, etc. Other examples include any UE identified by the 3GPP, including a Narrowband Internet of Things (NB-IoT) UE, a Machine Type Communication (MTC) UE, and / or an enhanced MTC (eMTC) UE.

[0194] A UE may support Device-to-Device (D2D) communication, for example by implementing a 3GPP standard for sidelink communication, Dedicated Short-Range Communication (DSRC), Vehicle-to-Vehicle (V2V), Vehicle-to-Infrastructure (V2I), or Vehicle- to-Everything (V2X). In other examples, a UE may not necessarily have a user in the sense of a human user who owns and / or operates the relevant device. Instead, a UE may represent a device that is intended for sale to, or operation by, a human user but which may not, or which may not initially, be associated with a specific human user (e.g., a smart sprinkler controller). Alternatively, a UE may represent a device that is not intended for sale to, or operation by, an end user but which may be associated with or operated for the benefit of a user (e.g., a smart power meter).

[0195] The UE 500 includes processing circuitry 502 that is operatively coupled via a bus 504 to an input / output interface 506, a power source 508, memory 510, a communication interface 512, and / or any other component, or any combination thereof. Certain UEs may utilize all or a subset of the components shown in Figure 5. The level of integration between the components may vary from one UE to another UE. Further, certain UEs may contain multiple instances of a component, such as multiple processors, memories, transceivers, transmitters, receivers, etc.

[0196] The processing circuitry 502 is configured to process instructions and data and may be configured to implement any sequential state machine operative to execute instructions stored as machine-readable computer programs in the memory 510. The processing circuitry 502 may be implemented as one or more hardware-implemented state machines (e.g., in discrete logic, Field Programmable Gate Arrays (FPGAs), Application Specific Integrated Circuits (ASICs), etc.); programmable logic together with appropriate firmware; one or more stored computer programs, general purpose processors, such as a microprocessor or Digital Signal Processor (DSP), togetherwith appropriate software; or any combination of the above. For example, the processing circuitry 502 may include multiple Central Processing Units (CPUs).

[0197] In the example, the input / output interface 506 may be configured to provide an interface or interfaces to an input device, output device, or one or more input and / or output devices. Examples of an output device include a speaker, a sound card, a video card, a display, a monitor, a printer, an actuator, an emitter, a smartcard, another output device, or any combination thereof. An input device may allow a user to capture information into the UE 500. Examples of an input device include a touch-sensitive or presence-sensitive display, a camera (e.g., a digital camera, a digital video camera, a web camera, etc.), a microphone, a sensor, a mouse, a trackball, a directional pad, a trackpad, a scroll wheel, a smartcard, and the like. The presence-sensitive display may include a capacitive or resistive touch sensor to sense input from a user. A sensor may be, for instance, an accelerometer, a gyroscope, a tilt sensor, a force sensor, a magnetometer, an optical sensor, a proximity sensor, a biometric sensor, etc., or any combination thereof. An output device may use the same type of interface port as an input device. For example, a Universal Serial Bus (USB) port may be used to provide an input device and an output device.

[0198] In some embodiments, the power source 508 is structured as a battery or battery pack. Other types of power sources, such as an external power source (e.g., an electricity outlet), photovoltaic device, or power cell, may be used. The power source 508 may further include power circuitry for delivering power from the power source 508 itself, and / or an external power source, to the various parts of the UE 500 via input circuitry or an interface such as an electrical power cable. Delivering power may be, for example, for charging of the power source 508. Power circuitry may perform any formatting, converting, or other modification to the power from the power source 508 to make the power suitable for the respective components of the UE 500 to which power is supplied.

[0199] The memory 510 may be or be configured to include memory such as Random Access Memory (RAM), Read Only Memory (ROM), Programmable ROM (PROM), Erasable PROM (EPROM), Electrically EPROM (EEPROM), magnetic disks, optical disks, hard disks, removable cartridges, flash drives, and so forth. In one example, the memory 510 includes one or more application programs 514, such as an operating system, web browser application, a widget, gadget engine, or other application, and corresponding data 516. The memory 510 may store, for use by the UE 500, any of a variety of various operating systems or combinations of operating systems.

[0200] The memory 510 may be configured to include a number of physical drive units, such as Redundant Array of Independent Disks (RAID), flash memory, USB flash drive, external hard disk drive, thumb drive, pen drive, key drive, High Density Digital Versatile Disc (HD-DVD)optical disc drive, internal hard disk drive, Blu-Ray optical disc drive, Holographic Digital Data Storage (HDDS) optical disc drive, external mini Dual In-line Memory Module (DIMM), Synchronous Dynamic RAM (SDRAM), external micro-DIMM SDRAM, smartcard memory such as a tamper resistant module in the form of a Universal Integrated Circuit Card (UICC) including one or more Subscriber Identity Modules (SIMs), such as a Universal SIM (USIM) and / or Internet Protocol Multimedia Services Identity Module (ISIM), other memory, or any combination thereof. The UICC may for example be an embedded UICC (eUICC), integrated UICC (iUICC) or a removable UICC commonly known as a ‘SIM card.’ The memory 510 may allow the UE 500 to access instructions, application programs, and the like stored on transitory or non-transitory memory media, to off-load data, or to upload data. An article of manufacture, such as one utilizing a communication system, may be tangibly embodied as or in the memory 510, which may be or comprise a device-readable storage medium.

[0201] The processing circuitry 502 may be configured to communicate with an access network or other network using the communication interface 512. The communication interface 512 may comprise one or more communication subsystems and may include or be communicatively coupled to an antenna 522. The communication interface 512 may include one or more transceivers used to communicate, such as by communicating with one or more remote transceivers of another device capable of wireless communication (e.g., another UE or a network node in an access network). Each transceiver may include a transmitter 518 and / or a receiver 520 appropriate to provide network communications (e.g., optical, electrical, frequency allocations, and so forth). Moreover, the transmitter 518 and receiver 520 may be coupled to one or more antennas (e.g., the antenna 522) and may share circuit components, software, or firmware, or alternatively be implemented separately.

[0202] In the illustrated embodiment, communication functions of the communication interface 512 may include cellular communication, WiFi communication, LPWAN communication, data communication, voice communication, multimedia communication, short- range communications such as Bluetooth, NFC, location-based communication such as the use of the Global Positioning System (GPS) to determine a location, another like communication function, or any combination thereof. Communications may be implemented according to one or more communication protocols and / or standards, such as IEEE 802.11, Code Division Multiplexing Access (CDMA), Wideband CDMA (WCDMA), GSM, LTE, NR, UMTS, WiMax, Ethernet, Transmission Control Protocol / Internet Protocol (TCP / IP), Synchronous Optical Networking (SONET), Asynchronous Transfer Mode (ATM), Quick User Datagram Protocol Internet Connection (QUIC), Hypertext Transfer Protocol (HTTP), and so forth.

[0203] Regardless of the type of sensor, a UE may provide an output of data captured by its sensors, through its communication interface 512, via a wireless connection to a network node. Data captured by sensors of a UE can be communicated through a wireless connection to a network node via another UE. The output may be periodic (e.g., once every 15 minutes if it reports the sensed temperature), random (e.g., to even out the load from reporting from several sensors), in response to a triggering event (e.g., when moisture is detected, an alert is sent), in response to a request (e.g., a user initiated request), or a continuous stream (e.g., a live video feed of a patient).

[0204] As another example, a UE comprises an actuator, a motor, or a switch related to a communication interface configured to receive wireless input from a network node via a wireless connection. In response to the received wireless input the states of the actuator, the motor, or the switch may change. For example, the UE may comprise a motor that adjusts the control surfaces or rotors of a drone in flight according to the received input or to a robotic arm performing a medical procedure according to the received input.

[0205] A UE, when in the form of an loT device, may be a device for use in one or more application domains, these domains comprising, but not limited to, city wearable technology, extended industrial application, and healthcare. Non-limiting examples of such an loT device are a device which is or which is embedded in: a connected refrigerator or freezer, a television, a connected lighting device, an electricity meter, a robot vacuum cleaner, a voice controlled smart speaker, a home security camera, a motion detector, a thermostat, a smoke detector, a door / window sensor, a flood / moisture sensor, an electrical door lock, a connected doorbell, an air conditioning system like a heat pump, an autonomous vehicle, a surveillance system, a weather monitoring device, a vehicle parking monitoring device, an electric vehicle charging station, a smart watch, a fitness tracker, a head-mounted display for Augmented Reality (AR) or VR, a wearable for tactile augmentation or sensory enhancement, a water sprinkler, an animal- or item-tracking device, a sensor for monitoring a plant or animal, an industrial robot, an Unmanned Aerial Vehicle (UAV), and any kind of medical device, like a heart rate monitor or a remote controlled surgical robot. A UE in the form of an loT device comprises circuitry and / or software in dependence of the intended application of the loT device in addition to other components as described in relation to the UE 500 shown in Figure 5.

[0206] As yet another specific example, in an loT scenario, a UE may represent a machine or other device that performs monitoring and / or measurements and transmits the results of such monitoring and / or measurements to another UE and / or a network node. The UE may in this case be an M2M device, which may in a 3GPP context be referred to as an MTC device. As one particular example, the UE may implement the 3GPP NB-IoT standard. In other scenarios, a UEmay represent a vehicle, such as a car, a bus, a truck, a ship, an airplane, or other equipment that is capable of monitoring and / or reporting on its operational status or other functions associated with its operation.

[0207] In practice, any number of UEs may be used together with respect to a single use case. For example, a first UE might be or be integrated in a drone and provide the drone’s speed information (obtained through a speed sensor) to a second UE that is a remote controller operating the drone. When the user makes changes from the remote controller, the first UE may adjust the throttle on the drone (e.g., by controlling an actuator) to increase or decrease the drone’s speed. The first and / or the second UE can also include more than one of the functionalities described above. For example, a UE might comprise the sensor and the actuator and handle communication of data for both the speed sensor and the actuators.

[0208] Figure 6 shows a network node 600 in accordance with some embodiments. As used herein, network node refers to equipment capable, configured, arranged, and / or operable to communicate directly or indirectly with a UE and / or with other network nodes or equipment in a telecommunication network. Examples of network nodes include, but are not limited to, APs (e.g., radio APs), Base Stations (BSs) (e.g., radio BSs, Node Bs, evolved Node Bs (eNBs), NR Node Bs (gNBs)), and O-RAN nodes or components of an O-RAN node (e.g., O-RU, O-DU, O-CU).

[0209] Base stations may be categorized based on the amount of coverage they provide (or, stated differently, their transmit power level) and so, depending on the provided amount of coverage, may be referred to as femto base stations, pico base stations, micro base stations, or macro base stations. A base station may be a relay node or a relay donor node controlling a relay. A network node may also include one or more (or all) parts of a distributed radio base station such as centralized digital units, distributed units (e.g., in an O-RAN access node), and / or Remote Radio Units (RRUs), sometimes referred to as Remote Radio Heads (RRHs). Such RRUs may or may not be integrated with an antenna as an antenna integrated radio. Parts of a distributed radio base station may also be referred to as nodes in a Distributed Antenna System (DAS).

[0210] Other examples of network nodes include multiple Transmission Point (multi-TRP) 5G access nodes, Multi-Standard Radio (MSR) equipment such as MSR BSs, network controllers such as Radio Network Controllers (RNCs) or BS Controllers (BSCs), Base Transceiver Stations (BTSs), transmission points, transmission nodes, Multi-Cell / Multicast Coordination Entities (MCEs), Operation and Maintenance (O&M) nodes, Operations Support System (OSS) nodes, Self-Organizing Network (SON) nodes, positioning nodes (e.g., Evolved Serving Mobile Location Centers (E-SMLCs)), and / or Minimization of Drive Tests (MDTs).

[0211] The network node 600 includes processing circuitry 602, memory 604, a communication interface 606, and a power source 608. The network node 600 may be composed of multiple physically separate components (e.g., a NodeB component and an RNC component, or a BTS component and a BSC component, etc.), which may each have their own respective components. In certain scenarios in which the network node 600 comprises multiple separate components (e.g., BTS and BSC components), one or more of the separate components may be shared among several network nodes. For example, a single RNC may control multiple NodeBs. In such a scenario, each unique NodeB and RNC pair may in some instances be considered a single separate network node. In some embodiments, the network node 600 may be configured to support multiple RATs. In such embodiments, some components may be duplicated (e.g., separate memory 604 for different RATs) and some components may be reused (e.g., a same antenna 610 may be shared by different RATs). The network node 600 may also include multiple sets of the various illustrated components for different wireless technologies integrated into network node 600, for example GSM, WCDMA, LTE, NR, WiFi, Zigbee, Z-wave, Long Range Wide Area Network (LoRaWAN), Radio Frequency Identification (RFID), or Bluetooth wireless technologies. These wireless technologies may be integrated into the same or different chip or set of chips and other components within the network node 600.

[0212] The processing circuitry 602 may comprise a combination of one or more of a microprocessor, controller, microcontroller, CPU, DSP, ASIC, FPGA, or any other suitable computing device, resource, or combination of hardware, software, and / or encoded logic operable to provide, either alone or in conjunction with other network node 600 components, such as the memory 604, to provide network node 600 functionality.

[0213] In some embodiments, the processing circuitry 602 includes a System on a Chip (SOC). In some embodiments, the processing circuitry 602 includes one or more of Radio Frequency (RF) transceiver circuitry 612 and baseband processing circuitry 614. In some embodiments, the RF transceiver circuitry 612 and the baseband processing circuitry 614 may be on separate chips (or sets of chips), boards, or units, such as radio units and digital units. In alternative embodiments, part or all of the RF transceiver circuitry 612 and the baseband processing circuitry 614 may be on the same chip or set of chips, boards, or units.

[0214] The memory 604 may comprise any form of volatile or non-volatile computer-readable memory including, without limitation, persistent storage, solid state memory, remotely mounted memory, magnetic media, optical media, RAM, ROM, mass storage media (for example, a hard disk), removable storage media (for example, a flash drive, a Compact Disk (CD), or a Digital Video Disk (DVD)), and / or any other volatile or non-volatile, non- transitory device-readable,and / or computer-executable memory devices that store information, data, and / or instructions that may be used by the processing circuitry 602. The memory 604 may store any suitable instructions, data, or information, including a computer program, software, an application including one or more of logic, rules, code, tables, and / or other instructions capable of being executed by the processing circuitry 602 and utilized by the network node 600. The memory 604 may be used to store any calculations made by the processing circuitry 602 and / or any data received via the communication interface 606. In some embodiments, the processing circuitry 602 and the memory 604 are integrated.

[0215] The communication interface 606 is used in wired or wireless communication of signaling and / or data between a network node, access network, and / or UE. As illustrated, the communication interface 606 comprises port(s) / terminal(s) 616 to send and receive data, for example to and from a network over a wired connection. The communication interface 606 also includes radio front-end circuitry 618 that may be coupled to, or in certain embodiments a part of, the antenna 610. The radio front-end circuitry 618 comprises filters 620 and amplifiers 622. The radio front-end circuitry 618 may be connected to the antenna 610 and the processing circuitry 602. The radio front-end circuitry 618 may be configured to condition signals communicated between the antenna 610 and the processing circuitry 602. The radio front-end circuitry 618 may receive digital data that is to be sent out to other network nodes or UEs via a wireless connection. The radio front-end circuitry 618 may convert the digital data into a radio signal having the appropriate channel and bandwidth parameters using a combination of the filters 620 and / or the amplifiers 622. The radio signal may then be transmitted via the antenna 610. Similarly, when receiving data, the antenna 610 may collect radio signals which are then converted into digital data by the radio front-end circuitry 618. The digital data may be passed to the processing circuitry 602. In other embodiments, the communication interface 606 may comprise different components and / or different combinations of components.

[0216] In certain alternative embodiments, the network node 600 does not include separate radio front-end circuitry 618; instead, the processing circuitry 602 includes radio front-end circuitry and is connected to the antenna 610. Similarly, in some embodiments, all or some of the RF transceiver circuitry 612 is part of the communication interface 606. In still other embodiments, the communication interface 606 includes the one or more ports or terminals 616, the radio front-end circuitry 618, and the RF transceiver circuitry 612 as part of a radio unit (not shown), and the communication interface 606 communicates with the baseband processing circuitry 614, which is part of a digital unit (not shown).

[0217] The antenna 610 may include one or more antennas, or antenna arrays, configured to send and / or receive wireless signals. The antenna 610 may be coupled to the radio front-end circuitry 618 and may be any type of antenna capable of transmitting and receiving data and / or signals wirelessly. In certain embodiments, the antenna 610 is separate from the network node 600 and connectable to the network node 600 through an interface or port.

[0218] The antenna 610, the communication interface 606, and / or the processing circuitry 602 may be configured to perform any receiving operations and / or certain obtaining operations described herein as being performed by the network node 600. Any information, data, and / or signals may be received from a UE, another network node, and / or any other network equipment. Similarly, the antenna 610, the communication interface 606, and / or the processing circuitry 602 may be configured to perform any transmitting operations described herein as being performed by the network node 600. Any information, data, and / or signals may be transmitted to a UE, another network node, and / or any other network equipment.

[0219] The power source 608 provides power to the various components of the network node 600 in a form suitable for the respective components (e.g., at a voltage and current level needed for each respective component). The power source 608 may further comprise, or be coupled to, power management circuitry to supply the components of the network node 600 with power for performing the functionality described herein. For example, the network node 600 may be connectable to an external power source (e.g., the power grid or an electricity outlet) via input circuitry or an interface such as an electrical cable, whereby the external power source supplies power to power circuitry of the power source 608. As a further example, the power source 608 may comprise a source of power in the form of a battery or battery pack which is connected to, or integrated in, power circuitry. The battery may provide backup power should the external power source fail.

[0220] Embodiments of the network node 600 may include additional components beyond those shown in Figure 6 for providing certain aspects of the network node’s functionality, including any of the functionality described herein and / or any functionality necessary to support the subject matter described herein. For example, the network node 600 may include user interface equipment to allow input of information into the network node 600 and to allow output of information from the network node 600. This may allow a user to perform diagnostic, maintenance, repair, and other administrative functions for the network node 600. In some embodiments providing a core network node, such as core network node 108 of FIG. 2, some components, such as the radio front-end circuitry 618 and the RF transceiver circuitry 612 may be omitted.

[0221] Figure 7 is a block diagram illustrating a virtualization environment 700 in which functions implemented by some embodiments may be virtualized. In the present context, virtualizing means creating virtual versions of apparatuses or devices which may include virtualizing hardware platforms, storage devices, and networking resources. As used herein, virtualization can be applied to any device described herein, or components thereof, and relates to an implementation in which at least a portion of the functionality is implemented as one or more virtual components. Some or all of the functions described herein may be implemented as virtual components executed by one or more Virtual Machines (VMs) implemented in one or more virtualization environments 700 hosted by one or more of hardware nodes, such as a hardware computing device that operates as a network node, a UE, a core network node, or a host. Further, in embodiments in which the virtual node does not require radio connectivity (e.g., a core network node or host), then the node may be entirely virtualized. In some embodiments, the virtualization environment 700 includes components defined by the O-RAN Alliance, such as an O-Cloud environment orchestrated by a Service Management and Orchestration Framework via an O-2 interface. Virtualization may facilitate distributed implementations of a network node, a UE, a core network node, or a host.

[0222] Applications 702 (which may alternatively be called software instances, virtual appliances, network functions, virtual nodes, virtual network functions, etc.) are run in the virtualization environment 700 to implement some of the features, functions, and / or benefits of some of the embodiments disclosed herein.

[0223] Hardware 704 includes processing circuitry, memory that stores software and / or instructions executable by hardware processing circuitry, and / or other hardware devices as described herein, such as a network interface, an input / output interface, and so forth. Software may be executed by the processing circuitry to instantiate one or more virtualization layers 706 (also referred to as hypervisors or Virtual Machine Monitors (VMMs)), provide VMs 708A and 708B (one or more of which may be generally referred to as VMs 708), and / or perform any of the functions, features, and / or benefits described in relation with some embodiments described herein. The virtualization layer 706 may present a virtual operating platform that appears like networking hardware to the VMs 708.

[0224] The VMs 708 comprise virtual processing, virtual memory, virtual networking, or interface and virtual storage, and may be run by a corresponding virtualization layer 706. Different embodiments of the instance of a virtual appliance 702 may be implemented on one or more of VMs 708, and the implementations may be made in different ways. Virtualization of the hardware is in some contexts referred to as Network Function Virtualization (NFV). NFV may be used toconsolidate many network equipment types onto industry standard high volume server hardware, physical switches, and physical storage, which can be located in data centers and customer premise equipment.

[0225] In the context of NFV, a VM 708 may be a software implementation of a physical machine that runs programs as if they were executing on a physical, non-virtualized machine. Each of the VMs 708, and that part of the hardware 704 that executes that VM, be it hardware dedicated to that VM and / or hardware shared by that VM with others of the VMs, forms separate virtual network elements. Still in the context of NFV, a virtual network function is responsible for handling specific network functions that run in one or more VMs 708 on top of the hardware 704 and corresponds to the application 702.

[0226] The hardware 704 may be implemented in a standalone network node with generic or specific components. The hardware 704 may implement some functions via virtualization. Alternatively, the hardware 704 may be part of a larger cluster of hardware (e.g., such as in a data center or CPE) where many hardware nodes work together and are managed via management and orchestration 710, which, among others, oversees lifecycle management of the applications 702. In some embodiments, the hardware 704 is coupled to one or more radio units that each include one or more transmitters and one or more receivers that may be coupled to one or more antennas. Radio units may communicate directly with other hardware nodes via one or more appropriate network interfaces and may be used in combination with the virtual components to provide a virtual node with radio capabilities, such as a radio access node or a base station. In some embodiments, some signaling can be provided with the use of a control system 712 which may alternatively be used for communication between hardware nodes and radio units.

[0227] Although the computing devices described herein (e.g., UEs, network nodes) may include the illustrated combination of hardware components, other embodiments may comprise computing devices with different combinations of components. It is to be understood that these computing devices may comprise any suitable combination of hardware and / or software needed to perform the tasks, features, functions, and methods disclosed herein. Determining, calculating, obtaining, or similar operations described herein may be performed by processing circuitry, which may process information by, for example, converting the obtained information into other information, comparing the obtained information or converted information to information stored in the network node, and / or performing one or more operations based on the obtained information or converted information, and as a result of said processing making a determination. Moreover, while components are depicted as single boxes located within a larger box, or nested within multiple boxes, in practice, computing devices may comprise multiple different physicalcomponents that make up a single illustrated component, and functionality may be partitioned between separate components. For example, a communication interface may be configured to include any of the components described herein, and / or the functionality of the components may be partitioned between the processing circuitry and the communication interface. In another example, non-computationally intensive functions of any of such components may be implemented in software or firmware and computationally intensive functions may be implemented in hardware.

[0228] In certain embodiments, some or all of the functionality described herein may be provided by processing circuitry executing instructions stored on in memory, which in certain embodiments may be a computer program product in the form of a non-transitory computer- readable storage medium. In alternative embodiments, some or all of the functionality may be provided by the processing circuitry without executing instructions stored on a separate or discrete device-readable storage medium, such as in a hard-wired manner. In any of those particular embodiments, whether executing instructions stored on a non-transitory computer-readable storage medium or not, the processing circuitry can be configured to perform the described functionality. The benefits provided by such functionality are not limited to the processing circuitry alone or to other components of the computing device, but are enjoyed by the computing device as a whole, and / or by end users and a wireless network generally.

[0229] Those skilled in the art will recognize improvements and modifications to the embodiments of the present disclosure. All such improvements and modifications are considered within the scope of the concepts disclosed herein.

[0230] p.ABBREVIATIONSAt least some of the following abbreviations may be used in this disclosure. If there is an inconsistency between abbreviations, preference should be given to how it is used above. If listed multiple times below, the first listing should be preferred over any subsequent listing(s).3GPP 3rd Generation Partnership Project 5G 5 th Generation 6G 6thGeneration ABS Almost Blank Subframe ARQ Automatic Repeat Request AWGN Additive White Gaussian Noise BCCH Broadcast Control Channel BCH Broadcast Channel CA Carrier Aggregation CC Carrier ComponentCCCH SDU Common Control Channel SDU CDMA Code Division Multiplex Access CGI Cell Global Identity CIR Channel Impulse Response CP Cyclic Prefix CPICH Common Pilot Channel CQI Channel Quality Information C-RNTI Cell RNTI CSI Channel State Information DCCH Dedicated Control Channel DL Downlink DM Demodulation DMRS Demodulation Reference Signal DRX Discontinuous Reception DTX Discontinuous Transmission DTCH Dedicated Traffic Channel DUT Device Under Test E-CID Enhanced Cell-ID (positioning method) Ec / No Received energy per chip divided by the power density in the band eMBMS Evolved Multimedia Broadcast Multicast Services ECGI Evolved CGI eNB E-UTRAN NodeB ePDCCH Enhanced Physical Downlink Control Channel E-SMLC Evolved Serving Mobile Location Center E-UTRAN Evolved Universal Terrestrial Radio Access Network FDD Frequency Division Duplex FFS For Further Study gNB Base station in NR GNSS Global Navigation Satellite System HARQ Hybrid Automatic Repeat Request HO Handover HSPA High Speed Packet Access HRPD High Rate Packet Data LOS Line of SightLPP LTE Positioning Protocol LTE Long-Term Evolution MAC Medium Access Control MAC Message Authentication Code MBSFN Multimedia Broadcast Multicast Service Single Frequency Network MBSFN ABS MBSFN Almost Blank Subframe MDT Minimization of Drive Tests MIB Master Information Block MME Mobility Management Entity MSC Mobile Switching Center NPDCCH Narrowband Physical Downlink Control Channel NR New Radio OCNG OFDMA Channel Noise Generator OFDM Orthogonal Frequency Division Multiplexing OFDMA Orthogonal Frequency Division Multiple Access OSS Operations Support System OTDOA Observed Time Difference of Arrival O&M Operation and Maintenance PBCH Physical Broadcast Channel P-CCPCH Primary Common Control Physical Channel PCell Primary Cell PCFICH Physical Control Format Indicator Channel PDCCH Physical Downlink Control Channel PDCP Packet Data Convergence Protocol PDP Power Delay Profile PDSCH Physical Downlink Shared Channel PGW Packet Gateway PHICH Physical Hybrid- ARQ Indicator Channel PLMN Public Land Mobile Network PMI Precoding Matrix Indicator PRACH Physical Random Access Channel PRS Positioning Reference Signal PSS Primary Synchronization Signal PUCCH Physical Uplink Control Channel PUSCH Physical Uplink Shared Channel RACH Random Access Channel QAM Quadrature Amplitude Modulation RAN Radio Access Network RAT Radio Access Technology RLC Radio Link Control RLM Radio Link Monitoring RNC Radio Network Controller RNTI Radio Network Temporary Identifier RRC Radio Resource Control RRM Radio Resource Management RS Reference Signal RSCP Received Signal Code Power RSRP Reference Symbol Received Power ORReference Signal Received PowerRSRQ Reference Signal Received Quality ORReference Symbol Received QualityRSSI Received Signal Strength Indicator RSTD Reference Signal Time Difference SCH Synchronization Channel SCell Secondary Cell SDAP Service Data Adaptation Protocol SDU Service Data Unit SFN System Frame Number SGW Serving Gateway SI System Information SIB System Information Block SNR Signal to Noise Ratio SON Self-Organizing Network ss Synchronization Signal sss Secondary Synchronization Signal TDD Time Division Duplex TDOA Time Difference of Arrival TOA Time of Arrival TSS Tertiary Synchronization Signal TTI Transmission Time Interval UE User Equipment UL Uplink UMTS Universal Mobile Telecommunications System USIM Universal Subscriber Identity Module UTDOA Uplink Time Difference of Arrival WCDMA Wideband CDMA WLAN Wireless Local Area Network

Claims

CLAIMS1. A method performed by a User Equipment, UE, (500) the method comprising: being configured (300) with at least one Conditional Ll / L2-Triggered Mobility, CLTM, candidate cell, each of the at least one CLTM candidate cell having an associated CLTM Candidate cell configuration, and / or an associated LTM execution condition; evaluating (302) the CLTM execution condition; in response to the CLTM execution condition being fulfilled, selecting (304) a CLTM candidate cell for which the CLTM execution condition has been fulfilled and applying (306) the CLTM candidate cell configuration of the selected CLTM candidate cell; for the selected CLTM candidate cell, determining (308) to perform a Random Access Channel, RACH,-less CLTM execution and / or selecting a beam of the selected CLTM candidate cell based on one or more criteria / rules; and performing (310) beam selection during a CLTM execution procedure based on one or more criteria / rules.

2. The method of claim 1 wherein: each CLTM candidate cell has an associated CLTM Candidate cell configuration to be applied and used by the UE (500) in CLTM execution.

3. The method of any of claims 1-2 wherein: each CLTM candidate cell has an associated LTM execution condition.

4. The method of any of claims 1-3 wherein: the CLTM execution condition comprises: a measurement of the LTM candidate cell becomes an offset (or threshold) better than a measurement of the serving cell.

5. The method of any of claims 1-4 wherein: an LTM execution condition is configured by receiving a measurement configuration identifier associated to one or more measurements.

6. The method of any of claims 1-5 wherein: when the CLTM execution condition is fulfilled, selecting a CLTM candidate cell for which the CLTM execution condition has been fulfilled and / or applying the CLTM candidate cell configuration associated to the selected CLTM candidate cell.

7. The method of any of claims 1-6 wherein the criteria / rules comprise one or more of: the availability of a valid Uplink, UL, grant; the availability of the Scheduling Request, SR, configuration; a measurement quantity; an availability of a pre-activated Transmission Configuration Indication, TCI, state; the Downlink, DL, synchronization ‘status’ associated to a beam of the selected CLTM candidate cell; the UL synchronization ‘status’ associated to a beam of the selected CLTM candidate cell; and the contention free random access dedicated configuration associated to a beam of the selected CLTM candidate cell.

8. The method of any of claims 1-7 wherein an CLTM execution condition comprises one or more of: a measurement of a CLTM candidate cell becoming an offset better than a measurement of a serving cell; a measurement of a CLTM candidate cell becoming higher than a threshold; and a measurement of a CLTM candidate cell becoming better than a threshold AND a measurement of a serving cell becoming worse than a second threshold.

9. The method of any of claims 1-8 further comprising: determining that the TA value is not valid, and in response to it, performing a randomaccess procedure with the selected LTM candidate cell.

10. The method of any of claims 1-9 wherein determining whether a previously provided Time Alignment, TA, value for the selected LTM candidate cell is valid or not comprises: determining whether a TA timer associated to the TA value is running.

11. The method of any of claims 1-10 wherein the TA timer associated to the TA value for the selected CLTM candidate cell is started when the UE (500) receives the TA value, wherein the UE (500) receives the TA value from a serving cell before the fulfillment of the LTM execution condition.

12. The method of any of claims 1-11 wherein when the TA timer expires the TA value is not valid.

13. A method performed by a network node (600) the method comprising: configuring (400) a User Equipment, UE, (500) with at least one Conditional L1 / L2- Triggered Mobility, CLTM, candidate cell, each of the at least one CLTM candidate cell having an associated CLTM Candidate cell configuration, and / or an associated LTM execution condition; in response to the CLTM execution condition being fulfilled, a UE (500) selecting (402) a CLTM candidate cell for which the CLTM execution condition has been fulfilled and the UE (500) applying (404) the CLTM candidate cell configuration of the selected CLTM candidate cell; for the selected CLTM candidate cell, receiving (406) a Random Access Channel, RACH,- less CLTM execution and / or selection of a beam of the selected CLTM candidate cell based on one or more criteria / rules; and receiving (408) a beam selection during a CLTM execution procedure based on one or more criteria / rules.

14. The method of claim 13 wherein: each CLTM candidate cell has an associated CLTM Candidate cell configuration to be applied and used by the UE (500) in CLTM execution.

15. The method of any of claims 13-14 wherein: each CLTM candidate cell has an associated LTM execution condition.

16. The method of any of claims 13-15 wherein: the CLTM execution condition comprises: a measurement of the LTM candidate cell becomes an offset (or threshold) better than a measurement of the serving cell.

17. The method of any of claims 13-16 wherein: an LTM execution condition is configured by receiving a measurement configuration identifier associated to one or more measurements.

18. The method of any of claims 13-17 wherein:when the CLTM execution condition is fulfilled, the UE (500) selecting a CLTM candidate cell for which the CLTM execution condition has been fulfilled and / or the UE (500) applying the CLTM candidate cell configuration associated to the selected CLTM candidate cell.

19. The method of any of claims 13-18 wherein the criteria / rules comprise one or more of: the availability of a valid Uplink, UL, grant; the availability of the Scheduling Request, SR, configuration; a measurement quantity; an availability of a pre-activated Transmission Configuration Indication, TCI, state; the Downlink, DL, synchronization ‘status’ associated to a beam of the selected CLTM candidate cell; the UL synchronization ‘status’ associated to a beam of the selected CLTM candidate cell; and the contention free random access dedicated configuration associated to a beam of the selected CLTM candidate cell.

20. The method of any of claims 13-19 wherein an CLTM execution condition comprises one or more of: a measurement of a CLTM candidate cell becoming an offset better than a measurement of a serving cell; a measurement of a CLTM candidate cell becoming higher than a threshold; and a measurement of a CLTM candidate cell becoming better than a threshold AND a measurement of a serving cell becoming worse than a second threshold.

21. The method of any of claims 13-20 further comprising: determining that the TA value is not valid, and in response to it, performing a randomaccess procedure with the selected LTM candidate cell.

22. The method of any of claims 13-21 wherein determining whether a previously provided Time Alignment, TA, value for the selected LTM candidate cell is valid or not comprises: determining whether a TA timer associated to the TA value is running.

23. The method of any of claims 13-22 wherein the TA timer associated to the TA value for the selected CLTM candidate cell is started when the UE (500) receives the TA value, whereinthe UE (500) receives the TA value from a serving cell before the fulfillment of the LTM execution condition.

24. The method of any of claims 13-23 wherein when the TA timer expires the TA value is not valid.

25. A User Equipment, UE, (500) comprising processing circuitry (502) and memory (510), the memory (510) comprising instructions to cause the UE (500) to: be configured (300) with at least one Conditional Ll / L2-Triggered Mobility, CLTM, candidate cell, each of the at least one CLTM candidate cell having an associated CLTM Candidate cell configuration, and / or an associated LTM execution condition; evaluate(302) the CLTM execution condition; in response to the CLTM execution condition being fulfilled, select (304) a CLTM candidate cell for which the CLTM execution condition has been fulfilled and apply (306) the CLTM candidate cell configuration of the selected CLTM candidate cell; for the selected CLTM candidate cell, determine (308) to perform a Random Access Channel, RACH,-less CLTM execution and / or selecting a beam of the selected CLTM candidate cell based on one or more criteria / rules; and perform (310) beam selection during a CLTM execution procedure based on one or more criteria / rules.

26. The UE (500) of claim 25 further comprising instructions to cause the UE (500) to: implement any of the features of claims 2-12.

27. A computer-readable medium comprising instructions which, when executed on at least one processor, cause the at least one processor to carry out the method according to any one of claims 1-12.

28. A network node (600) comprising processing circuitry (602) and memory (604), the memory (604) comprising instructions to cause the network node (600) to: configure (400) a User Equipment, UE, (500) with at least one Conditional L1 / L2- Triggered Mobility, CLTM, candidate cell, each of the at least one CLTM candidate cell having an associated CLTM Candidate cell configuration, and / or an associated LTM execution condition;in response to the CLTM execution condition being fulfilled, a UE (500) selecting (402) a CLTM candidate cell for which the CLTM execution condition has been fulfilled and the UE (500) applying (404) the CLTM candidate cell configuration of the selected CLTM candidate cell; for the selected CLTM candidate cell, receive (406) a Random Access Channel, RACH,- less CLTM execution and / or selection of a beam of the selected CLTM candidate cell based on one or more criteria / rules; and receive (408) a beam selection during a CLTM execution procedure based on one or more criteria / rules.

29. The network node (600) of claim 28 further comprising instructions to cause the network node (600) to: implement any of the features of claims 14-24.

30. A computer-readable medium comprising instructions which, when executed on at least one processor, cause the at least one processor to carry out the method according to any one of claims 13-24.

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